Semiconductor light-emitting device

Abstract

This semiconductor light-emitting device comprises: a substrate; a plurality of obverse-surface electrodes; a plurality of reverse-surface electrodes; a semiconductor light-emitting element; a first drive circuit; and a second drive circuit. The substrate has a substrate obverse surface and a substrate reverse surface. The obverse-surface electrodes are formed on the substrate obverse surface. The reverse-surface electrodes are formed on the substrate reverse surface, and are configured such that the semiconductor light-emitting device is mounted thereon. The semiconductor light-emitting element includes a first light-emitting unit and a second light-emitting unit. The first drive circuit drives the first light-emitting unit. The second drive circuit drives the second light-emitting unit. The semiconductor light-emitting element, the first drive circuit, and the second drive circuit are mounted on the obverse-surface electrodes.

Description

Semiconductor light-emitting device

[0001] The present disclosure relates to semiconductor light emitting devices.

[0002] One type of semiconductor light-emitting device is a semiconductor laser device that includes a semiconductor light-emitting element as a laser light source (see, for example, Patent Document 1). The semiconductor laser device of Patent Document 1 includes a plurality of leads that are rod-shaped members. The leads serve as terminal portions used when mounting the semiconductor laser device on electronic equipment or the like.

[0003] JP 2016-29718 A

[0004] [Summary] In recent years, there has been a demand for higher output semiconductor light emitting devices. To achieve this, semiconductor light emitting devices including multiple light emitting portions are increasingly being adopted. However, as the output of semiconductor light emitting devices increases, there is a need to prevent the semiconductor light emitting devices from becoming excessively hot.

[0005] a first driving circuit electrically connected to the first element surface electrode and configured to drive the first light emitting element; and a second driving circuit electrically connected to the second element surface electrode and configured to drive the second light emitting element. The semiconductor light emitting device according to one aspect of the present disclosure includes: a substrate having a substrate surface and a substrate back surface facing opposite to the substrate surface; a plurality of surface electrodes formed on the substrate surface; a plurality of back surface electrodes formed on the substrate back surface and configured to mount the semiconductor light emitting device; a semiconductor light emitting element including a first light emitting portion and a second light emitting portion; a first element surface electrode electrically connected to the first light emitting portion; a second element surface electrode electrically connected to the second light emitting portion; and an element back surface electrode electrically connected to both the first light emitting portion and the second light emitting portion; a first driving circuit electrically connected to the first element surface electrode and configured to drive the first light emitting portion; and a second driving circuit electrically connected to the second element surface electrode and configured to drive the second light emitting portion. The element back surface electrodes, the first driving circuit, and the second driving circuit of the semiconductor light emitting element are mounted on the plurality of surface electrodes.

[0006] FIG. 1 is a schematic plan view of a semiconductor light emitting device of a first embodiment. FIG. 2 is a schematic back view of the semiconductor light emitting device of FIG. 1. FIG. 3 is a schematic cross-sectional view of the semiconductor light emitting device taken along line F3-F3 in FIG. 1. FIG. 4 is a schematic cross-sectional view of the semiconductor light emitting device taken along line F4-F4 in FIG. 3. FIG. 5 is a schematic circuit diagram of a light emitting system including the semiconductor light emitting device of the first embodiment. FIG. 6 is a schematic cross-sectional view of the semiconductor light emitting device of FIG. 3 mounted on a circuit board. FIG. 7 is a schematic cross-sectional view for explaining a current path flowing within the semiconductor light emitting device. FIG. 8 is a schematic plan view of a semiconductor light emitting device of a second embodiment. FIG. 9 is a schematic back view of the semiconductor light emitting device of FIG. 8. FIG. 10 is a schematic plan view of a front-side intermediate electrode of the semiconductor light emitting device of FIG. 8. FIG. 11 is a schematic circuit diagram of a light emitting system including the semiconductor light emitting device of the second embodiment. FIG. 12 is a schematic plan view of a semiconductor light emitting device of a third embodiment. FIG. 13 is a schematic back view of the semiconductor light emitting device of FIG. 12. 14 is a schematic cross-sectional view of the semiconductor light emitting device taken along line F14-F14 in FIG. 12. FIG. 15 is a schematic cross-sectional view of the semiconductor light emitting device taken along line F15-F15 in FIG. 12. FIG. 16 is a schematic plan view of the semiconductor light emitting device of the fourth embodiment. FIG. 17 is a schematic back view of the semiconductor light emitting device of FIG. 16. FIG. 18 is a schematic enlarged plan view of a portion of the semiconductor light emitting device of FIG. 16. FIG. 19 is a schematic enlarged plan view of another portion of the semiconductor light emitting device of FIG. 16. FIG. 20 is a schematic circuit diagram of a light emitting system including the semiconductor light emitting device of the fifth embodiment. FIG. 21 is a schematic plan view of the semiconductor light emitting device of FIG. 20. FIG. 22 is a schematic back view of the semiconductor light emitting device of FIG. 21. FIG. 23 is a schematic plan view of a front-side intermediate electrode of the semiconductor light emitting device of FIG. 21. FIG. 24 is a schematic enlarged plan view of a portion of the semiconductor light emitting device of FIG. 20. FIG. 25 is a schematic enlarged plan view of another portion of the semiconductor light emitting device of FIG. 20. Fig. 26 is a schematic plan view enlarging yet another part of the semiconductor light emitting device of Fig. 20. Fig. 27 is a schematic circuit diagram of a light emitting system including a semiconductor light emitting device of a sixth embodiment. Fig. 28 is a schematic plan view of the semiconductor light emitting device of Fig. 27. Fig. 29 is a schematic back view of the semiconductor light emitting device of Fig. 28. Fig. 30 is a schematic plan view of a front surface side intermediate electrode of the semiconductor light emitting device of Fig. 28. Fig. 31 is a schematic plan view of a back surface side intermediate electrode of the semiconductor light emitting device of Fig. 28.Fig. 32 is a schematic plan view showing an enlargement of a portion of the semiconductor light emitting device of Fig. 28. Fig. 33 is a schematic plan view showing an enlargement of another portion of the semiconductor light emitting device of Fig. 28. Fig. 34 is a schematic plan view showing an enlargement of yet another portion of the semiconductor light emitting device of Fig. 28.

[0007] DETAILED DESCRIPTION Hereinafter, several embodiments of semiconductor light emitting devices according to the present disclosure will be described with reference to the accompanying drawings. Note that for simplicity and clarity of description, components shown in the drawings are not necessarily drawn to scale. Also, hatching lines may be omitted in cross-sectional views to facilitate understanding. The accompanying drawings merely illustrate embodiments of the present disclosure and should not be considered as limiting the present disclosure.

[0008] The following detailed description includes devices, systems, and methods embodying exemplary embodiments of the present disclosure. This detailed description is merely illustrative in nature and is not intended to limit the embodiments of the present disclosure or the application and uses of such embodiments.

[0009] First Embodiment A semiconductor light-emitting device 10 according to a first embodiment will be described with reference to FIGS. 1 to 7. FIG. 1 shows a schematic planar structure of the semiconductor light-emitting device 10. FIG. 2 shows a schematic rear surface structure of the semiconductor light-emitting device 10. FIG. 3 shows a schematic cross-sectional structure of the semiconductor light-emitting device 10 taken along line F3-F3 in FIG. 1. FIG. 4 shows a schematic cross-sectional structure of the semiconductor light-emitting device 10 taken along line F4-F4 in FIG. 3. FIG. 5 shows a schematic circuit configuration of a light-emitting system 800 including the semiconductor light-emitting device 10. FIG. 6 shows a schematic cross-sectional structure of the semiconductor light-emitting device 10 mounted on a circuit board 900. FIG. 7 is an explanatory diagram illustrating the flow of current through the semiconductor light-emitting device 10. Note that hatching has been omitted in FIG. 4 to facilitate understanding of the drawing. The term "planar view" used in the present disclosure refers to viewing the semiconductor light-emitting device 10 in the Z direction of the mutually orthogonal X, Y, and Z axes shown in FIG. 1. In the first embodiment, the "X direction" is an example of the "second direction," and the "Y direction" is an example of the "first direction."

[0010] 1, the semiconductor light emitting device 10 includes a substrate 20, a semiconductor light emitting element 30, a first drive circuit 40, and a second drive circuit 50 arranged on the substrate 20. The semiconductor light emitting element 30, the first drive circuit 40, and the second drive circuit 50 are arranged spaced apart from each other on the substrate 20.

[0011] The substrate 20 is a component that supports the semiconductor light emitting element 30, the first drive circuit 40, and the second drive circuit 50. The substrate 20 is formed in the shape of a rectangular flat plate with its thickness direction aligned in the Z direction. In the following description, "plan view" is synonymous with "viewed from the thickness direction of the substrate."

[0012] The substrate 20 is formed in a rectangular shape with the X direction as the longitudinal direction and the Y direction as the lateral direction in a plan view. The substrate 20 has a substrate front surface 21, a substrate back surface 22 facing the opposite side from the substrate front surface 21 in the Z direction, and first to fourth substrate side surfaces 23 to 26 connecting the substrate front surface 21 and the substrate back surface 22. The first substrate side surface 23 and the second substrate side surface 24 constitute both end surfaces of the substrate 20 in the X direction, and the third substrate side surface 25 and the fourth substrate side surface 26 constitute both end surfaces of the substrate 20 in the Y direction. The shape of the substrate 20 in a plan view can be changed as desired.

[0013] As shown in Fig. 3, the substrate 20 is a multilayer substrate. In the example shown in Fig. 3, the substrate 20 is a four-layer substrate. That is, the substrate 20 includes a plurality of front electrodes 28A, a plurality of rear electrodes 28B, a plurality of front-side intermediate electrodes 28C, and a plurality of rear-side intermediate electrodes 28D provided on a base material 27. Each of the front electrodes 28A, each rear electrode 28B, each front-side intermediate electrode 28C, and each rear-side intermediate electrode 28D is formed of a material including one or more appropriately selected from the group consisting of titanium (Ti), titanium nitride (TiN), gold (Au), silver (Ag), copper (Cu), aluminum (Al), and tungsten (W).

[0014] The base material 27 is made of, for example, an insulating material. The insulating material may be made of, for example, a material containing an epoxy resin. As an example, the base material 27 may be made of glass epoxy resin. The insulating material may also be made of, for example, a material containing ceramic. As a material containing ceramic, for example, aluminum nitride (AlN) or alumina (Al ２ O ３ ) and the like. When the substrate 27 is formed from a material containing ceramic, the heat dissipation performance of the substrate 27 is improved, thereby preventing the temperature of the semiconductor light-emitting device 10 from becoming excessively high. Here, the substrate front surface 21, the substrate back surface 22, and the first to fourth substrate side surfaces 23 to 26 refer to the substrate front surface, substrate back surface, and first to fourth substrate side surfaces of the substrate 27. More specifically, the substrate 27 includes three substrates: a front surface substrate 27A, a back surface substrate 27B, and an intermediate substrate 27C. The substrate front surface 21 of the substrate 20 is formed by the substrate front surface of the front surface substrate 27A. The substrate back surface 22 of the substrate 20 is formed by the substrate back surface of the back surface substrate 27B. The first to fourth substrate side surfaces of the substrate 20 are formed by the first to fourth substrate side surfaces of the front surface substrate 27A, the back surface substrate 27B, and the intermediate substrate 27C, respectively. On the first to fourth substrate side surfaces 23 to 26 (FIG. 3 shows the third substrate side surface 25 and the fourth substrate side surface 26), the ends of the front-side intermediate electrode 28C and the back-side intermediate electrode 28D are covered by the respective base materials 27A, 27B, and 27C. For convenience, in FIG. 3, the base materials 27A, 27B, and 27C and the portions covering the ends of the front-side intermediate electrode 28C and the back-side intermediate electrode 28D are distinguished by solid lines. The interfaces between the respective base materials 27A, 27B, and 27C may not be clear.

[0015] 1, a plurality of surface electrodes 28A are formed on the substrate surface 21. The plurality of surface electrodes 28A include a first surface electrode 61, second surface electrodes 62A and 62B, third surface electrodes 63A and 63B, and fourth surface electrodes 64A and 64B that are arranged spaced apart from one another.

[0016] The first surface electrode 61 is formed in a substantially rectangular ring shape on the outer periphery of the substrate surface 21. The first surface electrode 61 is symmetrical with respect to an imaginary center line VC extending along the Y direction at the center in the X direction of the substrate surface 21. The first surface electrode 61 includes first to fourth wiring portions 61A to 61D that form the respective sides of the substantially rectangular ring shape, and an opening 61E formed by the first to fourth wiring portions 61A to 61D.

[0017] The first wiring portion 61A is a wiring that extends along the Y direction at a position adjacent to the first substrate side surface 23 in the X direction. The second wiring portion 61B is a wiring that extends along the Y direction at a position adjacent to the second substrate side surface 24 in the X direction. The third wiring portion 61C is a wiring that extends along the X direction at a position adjacent to the third substrate side surface 25 in the Y direction. The fourth wiring portion 61D is a wiring that extends along the X direction at a position adjacent to the fourth substrate side surface 26 in the Y direction.

[0018] The width dimension WA3 of the third wiring portion 61C is larger than the width dimension WA1 of the first wiring portion 61A. The width dimension WA3 is larger than the width dimension WA2 of the second wiring portion 61B. The width dimension WA3 is smaller than the width dimension WA4 of the fourth wiring portion 61D. Here, the width dimension WA3 of the third wiring portion 61C is the dimension in the direction (Y direction) perpendicular to the direction (X direction) in which the third wiring portion 61C extends in a plan view. The width dimension WA1 of the first wiring portion 61A and the width dimension WA2 of the second wiring portion 61B are the dimensions in the direction (X direction) perpendicular to the direction (Y direction) in which the first wiring portion 61A and the second wiring portion 61B extend in a plan view. The width dimension WA4 of the fourth wiring portion 61D is the dimension in the direction (Y direction) perpendicular to the direction (X direction) in which the fourth wiring portion 61D extends in a plan view.

[0019] Enlarged regions 61F and 61G are formed between the first wiring portion 61A and the third wiring portion 61C, and between the second wiring portion 61B and the third wiring portion 61C, respectively. The enlarged region 61F is a region that enlarges the area of ​​the first surface electrode 61 between the first wiring portion 61A and the third wiring portion 61C. The enlarged region 61G is a region that enlarges the area of ​​the first surface electrode 61 between the second wiring portion 61B and the third wiring portion 61C. In the example shown in FIG. 1 , the enlarged regions 61F and 61G are formed in the shape of a right-angled trapezoid. Virtual lines VL1 and VL2 indicated by two-dot chain lines in FIG. 1 indicate portions of the first wiring portion 61A, the second wiring portion 61B, and the third wiring portion 61C, assuming that the enlarged regions 61F and 61G are not formed.

[0020] The second surface electrodes 62A and 62B, the third surface electrodes 63A and 63B, and the fourth surface electrodes 64A and 64B are arranged within the opening 61E of the first surface electrode 61 on the substrate surface 21 in a plan view. The second surface electrode 62A, the third surface electrode 63A, and the fourth surface electrode 64A are arranged closer to the first substrate side surface 23 than the imaginary center line VC, and the second surface electrode 62B, the third surface electrode 63B, and the fourth surface electrode 64B are arranged closer to the second substrate side surface 24 than the imaginary center line VC. In the example shown in FIG. 1 , the second surface electrode 62A, the third surface electrode 63A, and the fourth surface electrode 64A are in a line-symmetric relationship with the second surface electrode 62B, the third surface electrode 63B, and the fourth surface electrode 64B with respect to the imaginary center line VC. Therefore, in the following, only the second surface electrode 62A, the third surface electrode 63A, and the fourth surface electrode 64A will be described, and a description of the second surface electrode 62B, the third surface electrode 63B, and the fourth surface electrode 64B will be omitted.

[0021] The second surface electrode 62A is formed in a substantially L-shape in plan view. The second surface electrode 62A is disposed closer to the imaginary center line VC than the third surface electrode 63A and the fourth surface electrode 64A. The second surface electrode 62A includes a narrow portion 62AA and a wide portion 62AB. The narrow portion 62AA is a portion of the second surface electrode 62A that is smaller in dimension in the X direction. The wide portion 62AB is a portion of the second surface electrode 62A that is larger in dimension in the X direction. The narrow portion 62AA and the wide portion 62AB are aligned in the Y direction. In one example, the narrow portion 62AA and the wide portion 62AB are integrated. The narrow portion 62AA is disposed closer to the third wiring portion 61C of the first surface electrode 61, and the wide portion 62AB is disposed closer to the fourth wiring portion 61D of the first surface electrode 61. The second surface electrode 62B includes a narrow portion 62BA and a wide portion 62BB, similar to the second surface electrode 62A.

[0022] The third surface electrode 63A is formed to surround the wide portion 62AB of the second surface electrode 62A from one side in the X direction and one side in the Y direction. The third surface electrode 63A includes a first opposing portion, a second opposing portion, and a connecting portion. The first opposing portion and the second opposing portion constitute both ends of the third surface electrode 63A in the extension direction.

[0023] The first opposing portion is located closer to the third wiring portion 61C than the wide portion 62AB and faces the narrow portion 62AA in the X direction. The first opposing portion is disposed adjacent to the narrow portion 62AA in the X direction. The second opposing portion is located closer to the first wiring portion 61A than the wide portion 62AB and faces the fourth wiring portion 61D in the Y direction. The connecting portion connects the first opposing portion and the second opposing portion. The connecting portion extends obliquely toward the fourth wiring portion 61D as it approaches the first wiring portion 61A. In the example shown in FIG. 1 , the third surface electrode 63A is composed of a wiring having a constant width.

[0024] The fourth surface electrode 64A is formed to surround the third surface electrode 63A from one side in the X direction and one side in the Y direction. The fourth surface electrode 64A includes a first opposing portion, a second opposing portion, and a connecting portion. The first opposing portion and the second opposing portion constitute both ends of the fourth surface electrode 64A in the extension direction.

[0025] The first opposing portion is located closer to the third wiring portion 61C than the first opposing portion of the third surface electrode 63A and faces the narrow portion 62AA in the X direction. The first opposing portion is located adjacent to the narrow portion 62AA in the X direction. The first opposing portion of the fourth surface electrode 64A is aligned with the first opposing portion of the third surface electrode 63A in the Y direction. The second opposing portion of the fourth surface electrode 64A is located closer to the first wiring portion 61A than the second opposing portion of the third surface electrode 63A and faces the fourth wiring portion 61D in the Y direction. The connecting portion of the fourth surface electrode 64A connects the first opposing portion and the second opposing portion of the fourth surface electrode 64A. This connecting portion is located closer to the expanded region 61F than the connecting portion of the third surface electrode 63A. In the example shown in FIG. 1, the width dimension (dimension in the X direction) of the second opposing portion of the fourth surface electrode 64A is larger than the width dimension (dimension in the Y direction) of the first opposing portion of the fourth surface electrode 64A.

[0026] 1 , in a plan view, the area of ​​the first surface electrode 61 is larger than the areas of the second surface electrodes 62A and 62B, the third surface electrodes 63A and 63B, and the fourth surface electrodes 64A and 64B. In one example, the area of ​​the first surface electrode 61 is larger than the total area of ​​the second surface electrodes 62A and 62B, the third surface electrodes 63A and 63B, and the fourth surface electrodes 64A and 64B.

[0027] 2, the plurality of back surface electrodes 28B are formed on the substrate back surface 22. The plurality of back surface electrodes 28B include a first back surface electrode 71, second back surface electrodes 72A and 72B, third back surface electrodes 73A and 73B, and fourth back surface electrodes 74A and 74B that are arranged apart from one another.

[0028] The first back surface electrode 71 is a back surface electrode electrically connected to the first surface electrode 61 (see FIG. 1 ). The first back surface electrode 71 is formed so as to overlap the first surface electrode 61 in a plan view. The first back surface electrode 71 is formed so as to overlap at least the first wiring portion 61A and the fourth wiring portion 61D in a plan view. The first back surface electrode 71 is formed in a T-shape in a plan view. In one example, the first back surface electrode 71 has an axisymmetric shape with respect to the imaginary center line VC. The first back surface electrode 71 includes a wide portion 71A and a narrow portion 71B. In one example, the wide portion 71A and the narrow portion 71B are integrated.

[0029] The wide portion 71A is disposed closer to the third substrate side surface 25 than the center in the Y direction of the substrate back surface 22. The wide portion 71A is formed in the X direction over substantially the entire substrate back surface 22. In one example, the Y direction dimension WB1 of the wide portion 71A is greater than one-third and less than one-half of the Y direction dimension of the substrate back surface 22.

[0030] The narrow portion 71B is disposed closer to the fourth substrate side surface 26 than the wide portion 71A. The narrow portion 71B is disposed at the center of the substrate rear surface 22 in the X direction. In the Y direction, the tip of the narrow portion 71B is formed in a position adjacent to the fourth substrate side surface 26 in a plan view. In one example, the width dimension WB2 of the narrow portion 71B is larger than the dimension WB1 in the Y direction of the wide portion 71A.

[0031] The second back surface electrodes 72A, 72B are arranged dispersedly on both sides in the X direction of the narrow width portion 71B of the first back surface electrode 71. The third back surface electrodes 73A, 73B are arranged dispersedly on both sides in the X direction of the narrow width portion 71B of the first back surface electrode 71. The fourth back surface electrodes 74A, 74B are arranged dispersedly on both sides in the X direction of the narrow width portion 71B of the first back surface electrode 71. The second back surface electrode 72A, the third back surface electrode 73B, and the fourth back surface electrode 74A are arranged closer to the first substrate side surface 23 than the narrow width portion 71B, and the second back surface electrode 72B, the third back surface electrode 73B, and the fourth back surface electrode 74B are arranged closer to the second substrate side surface 24 than the narrow width portion 71B.

[0032] The second back surface electrode 72A and the second back surface electrode 72B are in a line-symmetric relationship with respect to the imaginary center line VC. The fourth back surface electrode 74A and the fourth back surface electrode 74B are in a line-symmetric relationship with respect to the imaginary center line VC. Therefore, hereinafter, the second back surface electrode 72A, the third back surface electrode 73A, and the fourth back surface electrode 74A will be described, and a description of the second back surface electrode 72B, the third back surface electrode 73B, and the fourth back surface electrode 74B will be omitted.

[0033] The second back surface electrode 72A is a back surface electrode electrically connected to the second surface electrode 62A (see FIG. 1). The second back surface electrode 72A includes a portion that overlaps with the wide portion 62AB (see FIG. 1) of the second surface electrode 62A in a plan view. The second back surface electrode 72A is disposed adjacent to the narrow portion 71B in the X direction. The second back surface electrode 72A extends in the Y direction. Of both Y direction ends of the second back surface electrode 72A, the end closer to the third substrate side surface 25 is disposed adjacent to the wide portion 71A in the Y direction. Of both Y direction ends of the second back surface electrode 72A, the end closer to the fourth substrate side surface 26 is formed adjacent to the fourth substrate side surface 26 in the Y direction. The end of the second back surface electrode 72A adjacent to the wide portion 71A in the Y direction includes a protrusion 72AA that protrudes toward the opposite side from the narrow portion 71B in the X direction. The protrusion 72AA is formed in a triangular shape in a plan view. The second back surface electrode 72B includes a protrusion 72BA, similar to the second back surface electrode 72A.

[0034] The third back surface electrode 73A is a back surface electrode electrically connected to the third surface electrode 63A (see FIG. 1 ). The third back surface electrode 73A includes a portion that overlaps with the second opposing portion of the third surface electrode 63A in a plan view. The third back surface electrode 73A is disposed on the opposite side of the narrow portion 71B with respect to the second back surface electrode 72A in the X direction. The third back surface electrode 73A extends in the Y direction. The Y direction dimension of the third back surface electrode 73A is smaller than the Y direction dimension of the second back surface electrode 72A. Of both Y direction end portions of the third back surface electrode 73A, the end closest to the fourth substrate side surface 26 is formed adjacent to the fourth substrate side surface 26 in the Y direction. Therefore, the distance between the third back surface electrode 73A and the wide portion 71A in the Y direction is greater than the distance between the second back surface electrode 72A and the wide portion 71A in the Y direction. A notch 73AA is formed at an end of the second back surface electrode 72A closer to the wide portion 71A in the Y direction so as to avoid the protrusion 72AA. Similarly to the third back surface electrode 73A, a notch 73BA is formed at the third back surface electrode 73B so as to avoid the protrusion 72BA.

[0035] The fourth back surface electrode 74A is a back surface electrode electrically connected to the fourth surface electrode 64A (see FIG. 1 ). The fourth back surface electrode 74A is disposed on the opposite side of the third back surface electrode 73A from the second back surface electrode 72A in the X direction. The fourth back surface electrode 74A extends in the Y direction. The Y direction dimension of the fourth back surface electrode 74A is smaller than the Y direction dimension of the third back surface electrode 73A. Of both Y direction end portions of the fourth back surface electrode 74A, the end portion closer to the fourth substrate side surface 26 is formed in a position adjacent to the fourth substrate side surface 26 in the Y direction. Therefore, the distance in the Y direction between the fourth back surface electrode 74A and the wide portion 71A is greater than the distance in the Y direction between the third back surface electrode 73A and the wide portion 71A.

[0036] 2 , in a plan view, the area of ​​the first back surface electrode 71 is larger than the areas of the second back surface electrodes 72A and 72B, the third back surface electrodes 73A and 73B, and the fourth back surface electrodes 74A and 74B. In one example, the area of ​​the first back surface electrode 71 is larger than the sum of the areas of the second back surface electrodes 72A and 72B, the third back surface electrodes 73A and 73B, and the fourth back surface electrodes 74A and 74B. In one example, the area of ​​the first back surface electrode 71 is more than twice the sum of the areas of the second back surface electrodes 72A and 72B, the third back surface electrodes 73A and 73B, and the fourth back surface electrodes 74A and 74B. In one example, the area of ​​the first back surface electrode 71 is more than three times the sum of the areas of the second back surface electrodes 72A and 72B, the third back surface electrodes 73A and 73B, and the fourth back surface electrodes 74A and 74B. In one example, the area of ​​the first rear surface electrode 71 is larger than half the area of ​​the rear surface 22 of the substrate.

[0037] 4, the plurality of surface-side intermediate electrodes 28C are formed within the substrate 27. More specifically, the plurality of surface-side intermediate electrodes 28C are sandwiched between the surface-side substrate 27A and the intermediate substrate 27C (see FIG. 3 for both). The plurality of surface-side intermediate electrodes 28C include a first intermediate electrode 81, second intermediate electrodes 82A and 82B, third intermediate electrodes 83A and 83B, and fourth intermediate electrodes 84A and 84B that are arranged spaced apart from one another.

[0038] The first intermediate electrode 81 is an intermediate electrode electrically connected to both the first front surface electrode 61 (see FIG. 1 ) and the first back surface electrode 71 (see FIG. 2 ). In a plan view, the area of ​​the first intermediate electrode 81 is larger than the area of ​​each of the second intermediate electrodes 82A and 82B, the third intermediate electrodes 83A and 83B, and the fourth intermediate electrodes 84A and 84B. In a plan view, the area of ​​the first intermediate electrode 81 is larger than the combined area of ​​the second intermediate electrodes 82A and 82B, the third intermediate electrodes 83A and 83B, and the fourth intermediate electrodes 84A and 84B. In a plan view, the area of ​​the first intermediate electrode 81 is larger than half the area of ​​the substrate surface of the intermediate substrate 27C. In a plan view, the area of ​​the first intermediate electrode 81 is larger than two-thirds the area of ​​the substrate surface of the intermediate substrate 27C. In one example, the first intermediate electrode 81 is formed over substantially the entire surface of the intermediate substrate 27C in a plan view.

[0039] The first intermediate electrode 81 includes two first openings 81AA and 81AB, two second openings 81BA and 81BB, and two third openings 81CA and 81CB. The first openings 81AA and 81AB are line-symmetric with respect to the imaginary center line VC. The second openings 81BA and 81BB are line-symmetric with respect to the imaginary center line VC. The third openings 81CA and 81CB are line-symmetric with respect to the imaginary center line VC. The first opening 81AA, the second opening 81BA, and the third opening 81CA are positioned closer to the first substrate side surface 23 than the imaginary center line VC, and the first opening 81AB, the second opening 81BB, and the third opening 81CB are positioned closer to the second substrate side surface 24 than the imaginary center line VC.

[0040] The first openings 81AA, 81AB are positioned closer to the imaginary center line VC than the second openings 81BA, 81BB and the third openings 81CA, 81CB. The second opening 81BA is positioned so as to overlap with the first opening 81AA when viewed from the X direction. The second opening 81BA is connected to an end of the first opening 81AA closer to the first substrate side surface 23 in the X direction. The third opening 81CA is positioned on the opposite side of the second opening 81BA from the first opening 81AA in the X direction. The third opening 81CA is positioned apart from the first opening 81AA and the second opening 81BA. The third opening 81CA is positioned so as to overlap with the second opening 81BA when viewed from the X direction. The second opening 81BB is positioned so as to overlap with the first opening 81AB when viewed from the X direction. The second opening 81BB communicates with an end of the second opening 81BA closer to the second substrate side surface 24 in the X direction. The third opening 81CB is located on the opposite side of the second opening 81BB from the first opening 81AB in the X direction. The third opening 81CB is located apart from the first opening 81AB and the second opening 81BB. The third opening 81CB is located at a position overlapping with the second opening 81BB when viewed from the X direction.

[0041] In a plan view, the second intermediate electrode 82A is disposed within the first opening 81AA. In a plan view, the second intermediate electrode 82B is disposed within the first opening 81AB. In a plan view, the third intermediate electrode 83A is disposed within the second opening 81BA. In a plan view, the third intermediate electrode 83B is disposed within the second opening 81BB. In a plan view, the fourth intermediate electrode 84A is disposed within the third opening 81CA. In a plan view, the fourth intermediate electrode 84B is disposed within the third opening 81CB.

[0042] The first openings 81AA, 81AB are formed in a substantially right-angled trapezoidal shape. Each corner of the first openings 81AA, 81AB is formed in a curved shape. The second openings 81BA, 81BB are formed in an elliptical shape with the Y direction as the longitudinal direction. The second openings 81BA, 81BB include portions that extend beyond the first openings 81AA, 81AB toward the fourth substrate side surface 26 when viewed from the X direction. The third openings 81CA, 81CB are formed in an elliptical shape with the X direction as the longitudinal direction.

[0043] The second intermediate electrodes 82A and 82B are in a line-symmetric relationship with respect to the imaginary center line VC. The third intermediate electrodes 83A and 83B are in a line-symmetric relationship with respect to the imaginary center line VC. The fourth intermediate electrodes 84A and 84B are in a line-symmetric relationship with respect to the imaginary center line VC. Therefore, the following description will focus on the second intermediate electrodes 82A, 83A, and 84A, and will omit a description of the second intermediate electrodes 82B, 83B, and 84B.

[0044] The second intermediate electrode 82A is formed in a substantially right-angled trapezoidal shape in a plan view. The second intermediate electrode 82A is slightly smaller than the first opening 81AA. The third intermediate electrode 83A is formed in an oval shape with the Y direction as the longitudinal direction and the X direction as the transverse direction in a plan view. The third intermediate electrode 83A is slightly smaller than the second opening 81BA. The fourth intermediate electrode 84A is formed in an oval shape with the X direction as the longitudinal direction and the Y direction as the transverse direction in a plan view. The fourth intermediate electrode 84A is slightly smaller than the third opening 81CA. The multiple back-side intermediate electrodes 28D have the same configuration as the multiple front-side intermediate electrodes 28C. Therefore, a detailed description of the multiple back-side intermediate electrodes 28D will be omitted.

[0045] 1 to 4 , the substrate 20 includes first vias 91A and 91B, second vias 92A and 92B, third vias 93A and 93B, and fourth vias 94A and 94B. The first vias 91A and 91B, second vias 92A and 92B, third vias 93A and 93B, and fourth vias 94A and 94B are provided to penetrate the respective base materials 27A, 27B, and 27C, the front-side intermediate electrode 28C, and the back-side intermediate electrode 28D in the Z direction. The first vias 91A and 91B, second vias 92A and 92B, third vias 93A and 93B, and fourth vias 94A and 94B may be provided to penetrate the front-side electrode 28A and the back-side electrode 28B in the Z direction. The first vias 91A, 91B, the second vias 92A, 92B, the third vias 93A, 93B, and the fourth vias 94A, 94B are formed from a material containing one or more appropriately selected from the group consisting of Ti, TiN, Au, Ag, Cu, Al, and W.

[0046] A plurality of first vias 91A and a plurality of first vias 91B are provided. The first vias 91A and the first vias 91B are electrically connected to the first surface electrode 61, the first intermediate electrode 81 of the surface-side intermediate electrode 28C, the first intermediate electrode 81 of the back-side intermediate electrode 28D, and the first back-side electrode 71. As a result, the first surface electrode 61, the first intermediate electrode 81 of the surface-side intermediate electrode 28C, the first intermediate electrode 81 of the back-side intermediate electrode 28D, and the first back-side electrode 71 are electrically connected to one another.

[0047] As shown in FIG. 1 , the multiple first vias 91A are provided in the third wiring portion 61C of the first surface electrode 61. More specifically, the multiple first vias 91A are provided in the center of the third wiring portion 61C in the X direction. Therefore, in a plan view, the multiple first vias 91A are arranged in positions of the third wiring portion 61C that overlap with the semiconductor light emitting element 30. The multiple first vias 91A are arranged spaced apart from each other in the X direction and the Y direction. The number of first vias 91A arranged in the X direction is greater than the number of first vias 91A arranged in the Y direction. In a plan view, the region in which the multiple first vias 91A are formed is larger than the area of ​​the semiconductor light emitting element 30. Therefore, some of the multiple first vias 91A are arranged outward from the semiconductor light emitting element 30 in a plan view.

[0048] As shown in FIG. 1 , the multiple first vias 91B are provided in the fourth wiring portion 61D of the first surface electrode 61. More specifically, the multiple first vias 91B are provided in the center of the fourth wiring portion 61D in the X direction. In the example shown in FIG. 1 , the multiple first vias 91B are provided closer to the fourth substrate side surface 26 in the fourth wiring portion 61D. In other words, the multiple first vias 91B are not provided at the end of the fourth wiring portion 61D in the Y direction that is closer to the second surface electrodes 62A, 62B. The multiple first vias 91B are arranged spaced apart from each other in the X and Y directions. The arrangement and number of the multiple first vias 91B are the same as those of the multiple first vias 91A. In the example shown in FIG. 1 , the multiple first vias 91B are provided at the same position in the X direction as the multiple first vias 91A.

[0049] As shown in FIGS. 1 to 4 , a plurality of second vias 92A and a plurality of second vias 92B are provided. The number of second vias 92A and a plurality of second vias 92B are fewer than the number of first vias 91A and a plurality of first vias 91B. The second vias 92A are electrically connected to the second surface electrode 62A, the second intermediate electrode 82A of the surface-side intermediate electrode 28C, the second intermediate electrode 82A of the back-side intermediate electrode 28D, and the second back-side electrode 72A. As a result, the second surface electrode 62A, the second intermediate electrode 82A of the surface-side intermediate electrode 28C, the second intermediate electrode 82A of the back-side intermediate electrode 28D, and the second back-side electrode 72A are electrically connected to one another. The second via 92B is electrically connected to the second surface electrode 62B, the second intermediate electrode 82B of the surface-side intermediate electrode 28C, the second intermediate electrode 82B of the back-side intermediate electrode 28D, and the second back-side electrode 72B. As a result, the second front surface electrode 62B, the second intermediate electrode 82B of the front surface side intermediate electrode 28C, the second intermediate electrode 82B of the rear surface side intermediate electrode 28D, and the second rear surface electrode 72B are electrically connected to one another.

[0050] 1, the plurality of second vias 92A are provided in a portion of the wide portion 62AB of the second surface electrode 62A that is closer to the first substrate side surface 23. As shown in Fig. 2, the plurality of second vias 92A are provided in one of both Y-direction end portions of the second back surface electrode 72A that is closer to the wide portion 71A of the first back surface electrode 71. Some of the plurality of second vias 92A are provided in the protruding portion 72AA of the second back surface electrode 72A.

[0051] 1, the plurality of second vias 92B are provided in a portion of the wide portion 62BB of the second surface electrode 62B that is closer to the second substrate side surface 24. As shown in Fig. 2, the plurality of second vias 92B are provided in one of both Y-direction end portions of the second back surface electrode 72B that is closer to the wide portion 71A of the first back surface electrode 71. Some of the plurality of second vias 92B are provided in the protruding portion 72BA of the second back surface electrode 72B.

[0052] As shown in FIGS. 1 to 4 , a plurality of third vias 93A and a plurality of third vias 93B are provided. The number of third vias 93A and a plurality of third vias 93B are fewer than the number of second vias 92A and a plurality of second vias 92B. The third via 93A is electrically connected to the third surface electrode 63A, the third intermediate electrode 83A of the surface-side intermediate electrode 28C, the third intermediate electrode 83A of the back-side intermediate electrode 28D, and the third back-side electrode 73A. As a result, the third surface electrode 63A, the third intermediate electrode 83A of the surface-side intermediate electrode 28C, the third intermediate electrode 83A of the back-side intermediate electrode 28D, and the third back-side electrode 73A are electrically connected to one another. The third via 93B is electrically connected to the third surface electrode 63B, the third intermediate electrode 83B of the surface-side intermediate electrode 28C, the third intermediate electrode 83B of the back-side intermediate electrode 28D, and the third back-side electrode 73B. As a result, the third front surface electrode 63B, the third intermediate electrode 83B of the front surface side intermediate electrode 28C, the third intermediate electrode 83B of the rear surface side intermediate electrode 28D, and the third rear surface electrode 73B are electrically connected to one another.

[0053] As shown in Fig. 1, the multiple third vias 93A are provided in the second opposing portion of the third surface electrode 63A. The multiple third vias 93A are arranged at the same position in the X direction and spaced apart from each other in the Y direction. As shown in Fig. 2, the multiple third vias 93A are provided at one of both Y direction end portions of the third back surface electrode 73A that is closer to the wide portion 71A of the first back surface electrode 71. In other words, the multiple third vias 93A are provided in a position of the third back surface electrode 73A adjacent to the notch 73AA in the X direction.

[0054] As shown in Fig. 1, the multiple third vias 93B are provided in the second opposing portion of the third surface electrode 63B. The multiple third vias 93B are arranged at the same position in the X direction and spaced apart from each other in the Y direction. As shown in Fig. 2, the multiple third vias 93B are provided at one of both Y direction end portions of the third back surface electrode 73B that is closer to the wide portion 71A of the first back surface electrode 71. In other words, the multiple third vias 93B are provided in a position adjacent to the notch 73BA in the X direction of the third back surface electrode 73B.

[0055] As shown in FIGS. 1 to 4 , a plurality of fourth vias 94A and a plurality of fourth vias 94B are provided. The number of fourth vias 94A and 94B is smaller than the number of second vias 92A and 92B. In one example, the number of fourth vias 94A and 94B is the same as the number of third vias 93A and 93B. The fourth via 94A is electrically connected to the fourth surface electrode 64A, the fourth intermediate electrode 84A of the surface-side intermediate electrode 28C, the fourth intermediate electrode 84A of the back-side intermediate electrode 28D, and the fourth back-side electrode 74A. As a result, the fourth surface electrode 64A, the fourth intermediate electrode 84A of the surface-side intermediate electrode 28C, the fourth intermediate electrode 84A of the back-side intermediate electrode 28D, and the fourth back-side electrode 74A are electrically connected to one another. The fourth via 94B is electrically connected to the fourth surface electrode 64B, the fourth intermediate electrode 84B of the surface-side intermediate electrode 28C, the fourth intermediate electrode 84B of the back-side intermediate electrode 28D, and the fourth back-side electrode 74B. As a result, the fourth surface electrode 64B, the fourth intermediate electrode 84B of the surface-side intermediate electrode 28C, the fourth intermediate electrode 84B of the back-side intermediate electrode 28D, and the fourth back-side electrode 74B are electrically connected to one another.

[0056] As shown in Fig. 1, the plurality of fourth vias 94A are provided in the second opposing portion of the fourth surface electrode 64A. The plurality of fourth vias 94A are arranged at the same position in the Y direction and spaced apart from each other in the X direction. As shown in Fig. 2, the plurality of fourth vias 94A are provided in one of both Y direction end portions of the fourth back surface electrode 74A, the end portion being closer to the wide portion 71A of the first back surface electrode 71.

[0057] 1, the plurality of fourth vias 94B are provided in the second opposing portion of the fourth surface electrode 64B. The plurality of fourth vias 94B are arranged at the same position in the Y direction and spaced apart from each other in the X direction. As shown in FIG. 2, the plurality of fourth vias 94B are provided at one of both Y-direction end portions of the fourth back surface electrode 74B, the end portion being closer to the wide portion 71A of the first back surface electrode 71.

[0058] 3, the substrate front surface 21 of the substrate 20 may be covered with a front surface resist 29A. Furthermore, the substrate back surface 22 of the substrate 20 may be covered with a back surface resist 29B. The front surface resist 29A and the back surface resist 29B are formed of an insulating material. The insulating material for forming the front surface resist 29A and the back surface resist 29B may be an insulating resin such as an epoxy resin or a polyimide resin. Furthermore, the front surface resist 29A and the back surface resist 29B may contain a filler such as silica or alumina.

[0059] The surface resist 29A includes openings that expose portions of the plurality of surface electrodes 28A. The semiconductor light emitting element 30, components of the first drive circuit 40, and components of the second drive circuit 50 are mounted on the surface electrodes 28A exposed by the openings in the surface resist 29A. In FIG. 1, the openings in the surface resist 29A are indicated by two-dot chain lines.

[0060] The back surface resist 29B includes openings that expose portions of the plurality of back surface electrodes 28B. The semiconductor light emitting device 10 is mounted on the circuit board 900 shown in Fig. 6 by the back surface electrodes 28B exposed by the openings in the back surface resist 29B. Therefore, the semiconductor light emitting device 10 can be said to be a surface-mounted device that is mounted on the surface of the circuit board 900. In Fig. 2, the openings in the back surface resist 29B are indicated by two-dot chain lines.

[0061] 1, semiconductor light-emitting elements 30, first drive circuits 40, and second drive circuits 50 are mounted on the plurality of surface electrodes 28A. The detailed configurations and mounting modes of the semiconductor light-emitting elements 30, first drive circuits 40, and second drive circuits 50 will be described below.

[0062] 1 and 3, the semiconductor light emitting element 30 is mounted on the third wiring portion 61C of the first surface electrode 61. More specifically, as shown in Fig. 3, the semiconductor light emitting element 30 is joined to the third wiring portion 61C by a conductive bonding material SD. The conductive bonding material SD may be a solder paste, a silver paste, a gold paste, or a copper paste.

[0063] 1, the semiconductor light emitting element 30 is disposed at the center of the third wiring portion 61C in the X direction. The semiconductor light emitting element 30 is disposed biased toward the third substrate side surface 25 with respect to the center of the third wiring portion 61C in the Y direction.

[0064] The semiconductor light emitting element 30 is formed in a rectangular plate shape with its thickness direction in the Z direction. In plan view, the shape of the semiconductor light emitting element 30 is a rectangle (rectangular shape) with its longitudinal direction in the X direction and its lateral direction in the Y direction. In one example, the dimension of the semiconductor light emitting element 30 in the Y direction is approximately half the width dimension WA3 of the third wiring portion 61C.

[0065] The semiconductor light-emitting element 30 is a laser diode that outputs laser light in a predetermined wavelength band and functions as a light source for the semiconductor light-emitting device 10. The semiconductor light-emitting element 30 is, for example, an edge-emitting laser (EEL). The semiconductor light-emitting element 30 includes a plurality of (eight in the first embodiment) light-emitting portions 33. Each light-emitting portion 33 is configured to emit laser light in a predetermined wavelength band. In other words, the semiconductor light-emitting element 30 is a multi-array edge-emitting laser element. This laser light may be visible light or laser light with a wavelength longer than visible light, such as infrared light. The plurality of light-emitting portions 33 are arranged side by side in the X direction.

[0066] As shown in FIG. 3 , the semiconductor light emitting element 30 includes an element front surface 31 and an element back surface 32 that face opposite each other in the Z direction. As shown in FIG. 1 , the element front surface 31 includes a plurality of element front surface electrodes 34 (eight in the first embodiment). The number of element front surface electrodes 34 is set according to the number of light emitting portions 33. That is, the plurality of element front surface electrodes 34 are provided individually for the plurality of light emitting portions 33. The plurality of element front surface electrodes 34 are individually electrically connected to the plurality of light emitting portions 33. The plurality of element front surface electrodes 34 are arranged at the same positions as each other in the Y direction and spaced apart from each other in the X direction. In one example, the plurality of element front surface electrodes 34 constitute anode electrodes for the plurality of light emitting portions 33.

[0067] 3 , an element back surface electrode 35 is formed on the element back surface 32. In one example, the element back surface electrode 35 is formed over the entire surface of the element back surface 32. The element back surface electrode 35 is electrically connected to the plurality of light-emitting portions 33. In other words, the element back surface electrode 35 serves as a common electrode for the plurality of light-emitting portions 33. In one example, the element back surface electrode 35 constitutes a common cathode electrode for the plurality of light-emitting portions 33.

[0068] 1, the first drive circuit 40 is a circuit that drives four of the eight light-emitting units 33 that are closer to the first substrate side surface 23. In the first embodiment, the four light-emitting units 33 driven by the first drive circuit 40 are referred to as "first light-emitting units 33A."

[0069] The second drive circuit 50 is a circuit that drives four of the eight light-emitting units 33 that are closer to the second substrate side surface 24. In the first embodiment, the four light-emitting units 33 driven by the second drive circuit 50 are referred to as "second light-emitting units 33B."

[0070] Hereinafter, the element surface electrode 34 provided for the first light-emitting portion 33A will be referred to as the "first element surface electrode 34A," and the element surface electrode 34 provided for the second light-emitting portion 33B will be referred to as the "second element surface electrode 34B." In the first embodiment, the first element surface electrode 34A is composed of four element surface electrodes 34, and the second element surface electrode 34B is composed of another four element surface electrodes 34. Furthermore, the first element surface electrode 34A constitutes the "first anode electrode," and the second element surface electrode 34B constitutes the "second anode electrode."

[0071] The first drive circuit 40 includes a first switching element 41 that controls the driving of the first light-emitting unit 33 A, and a first capacitor 42 that supplies current to the first light-emitting unit 33 A. The first switching element 41 and the first capacitor 42 are arranged apart from the semiconductor light-emitting element 30.

[0072] The first switching element 41 is mounted on the second surface electrode 62A. More specifically, as shown in Fig. 3, the first switching element 41 is joined to the second surface electrode 62A by a conductive bonding material SD.

[0073] 1, the first switching element 41 is mainly mounted on the narrow portion 62AA of the second surface electrode 62A. A portion of the first switching element 41 protrudes into the wide portion 62AB of the second surface electrode 62A. In other words, the first switching element 41 is disposed on the second surface electrode 62A near the semiconductor light emitting element 30. More specifically, the first switching element 41 is disposed on the second surface electrode 62A near the first light emitting portion 33A of the semiconductor light emitting element 30. When viewed from the Y direction, the first switching element 41 is disposed in a position overlapping with the first light emitting portion 33A.

[0074] For example, a vertical transistor is used as the first switching element 41. For example, a transistor such as a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor), an IGBT (Insulated Gate Bipolar Transistor), or a bipolar transistor is used as the first switching element 41. In the first embodiment, a MOSFET is used as the first switching element 41.

[0075] The first switching element 41 is formed in a rectangular plate shape with its thickness direction aligned in the Z direction. The first switching element 41 is formed in a square shape in plan view. The shape of the first switching element 41 in plan view can be changed as desired.

[0076] 3 , the first switching element 41 includes a second element front surface 41A and a second element back surface 41B that face opposite each other in the Z direction. The second element front surface 41A faces the same side as the substrate front surface 21, and the second element back surface 41B faces the same side as the substrate back surface 22. In other words, the second element back surface 41B faces the second surface electrode 62A. Here, the second element front surface 41A is an example of the "element front surface of the first switching element 41," and the second element back surface 41B is an example of the "element back surface of the first switching element 41."

[0077] As shown in FIG. 1 , a source electrode 41S and a gate electrode 41G are formed on the second element surface 41A. The source electrode 41S is formed over most of the second element surface 41A. The gate electrode 41G is formed at an end of the second element surface 41A closer to the first substrate side surface 23 in the X direction and at the center of the second element surface 41A in the Y direction. In one example, the gate electrode 41G is accommodated in a recess formed in the source electrode 41S. In a plan view, the gate electrode 41G faces the first opposing portion of the third surface electrode 63A in the X direction. In a plan view, the source electrode 41S includes a portion facing the first opposing portion of the fourth surface electrode 64A in the X direction.

[0078] 3, a drain electrode 41D is formed on the second element rear surface 41B. The drain electrode 41D is formed over the entire second element rear surface 41B. The drain electrode 41D is joined to the second surface electrode 62A by a conductive bonding material SD. In other words, the drain electrode 41D of the first switching element 41 is mounted on the second surface electrode 62A.

[0079] 1, the source electrode 41S of the first switching element 41 and the plurality of first element surface electrodes 34A are individually and electrically connected by a plurality of wires W1. The source electrode 41S of the first switching element 41 and the fourth surface electrode 64A are electrically connected by a wire W2. The gate electrode 41G of the first switching element 41 and the third surface electrode 63A are electrically connected by a wire W3. The wires W1 to W3 are bonding wires formed by a wire bonding device and are made of a conductor containing, for example, Au, Al, Cu, or the like.

[0080] 1 , in a plan view, the semiconductor light emitting element 30 and the first capacitor 42 are arranged spaced apart from each other in the Y direction. The first capacitor 42 is arranged on the opposite side of the first switching element 41 from the semiconductor light emitting element 30 in the Y direction. In other words, in a plan view, the first switching element 41 is arranged between the semiconductor light emitting element 30 and the first capacitor 42 in the Y direction.

[0081] A plurality of first capacitors 42 (six in the first embodiment) are provided. The plurality of first capacitors 42 are arranged spaced apart from one another in the X direction. Each first capacitor 42 is arranged to straddle the second surface electrode 62A and the fourth wiring portion 61D of the first surface electrode 61 in the Y direction. Each first capacitor 42 is mounted on the second surface electrode 62A and the fourth wiring portion 61D. More specifically, each first capacitor 42 is individually joined to the second surface electrode 62A and the fourth wiring portion 61D by a conductive bonding material SD.

[0082] Each first capacitor 42 includes a first electrode 42A and a second electrode 42B. In each first capacitor 42, the first electrode 42A and the second electrode 42B are disposed at the same position in the X direction and spaced apart in the Y direction. In the example of FIG. 1 , the first electrode 42A is bonded to the second surface electrode 62A by a conductive bonding material SD. This electrically connects the first electrode 42A to the second surface electrode 62A. The second electrode 42B is bonded to the fourth wiring portion 61D by a conductive bonding material SD. This electrically connects the second electrode 42B to the fourth wiring portion 61D (first surface electrode 61).

[0083] The first electrode 42A of each first capacitor 42 is disposed on the wide portion 62AB of the second surface electrode 62A. In the example of FIG. 1 , the first electrode 42A is disposed on the end of the wide portion 62AB closer to the fourth wiring portion 61D in the Y direction. The multiple first capacitors 42 arranged in the X direction are disposed across the entire wide portion 62AB in the X direction. In other words, the dimension of the wide portion 62AB in the X direction is set so that the multiple first capacitors 42 arranged in the X direction can be disposed thereon.

[0084] The second electrode 42B of each first capacitor 42 is disposed at one of the Y-direction ends of the fourth wiring portion 61D that is closer to the second surface electrode 62A. That is, the second electrode 42B of each first capacitor 42 is disposed closer to the second surface electrode 62A than the plurality of first vias 91B in the Y-direction. Some of the plurality of first capacitors 42 are disposed closer to the first substrate side surface 23 than the first switching elements 41 when viewed from the Y-direction.

[0085] The second drive circuit 50 includes a second switching element 51 that controls the driving of the second light-emitting unit 33B and a second capacitor 52 that supplies current to the second light-emitting unit 33B. The second switching element 51 is mounted on the narrow portion 62BA of the second surface electrode 62B. The arrangement and mounting of the second switching element 51 on the second surface electrode 62B are the same as the arrangement and mounting of the first switching element 41 on the second surface electrode 62A. Therefore, in a plan view, the distance D1 between the semiconductor light-emitting element 30 and the first switching element 41 in the Y direction is equal to the distance D2 between the semiconductor light-emitting element 30 and the second switching element 51 in the Y direction. Here, if the difference between the distance D1 and the distance D2 is, for example, within 10% of the distance D1, it can be said that the distance D1 is equal to the distance D2.

[0086] A vertical transistor is used as the second switching element 51. The second switching element 51 includes a second element front surface 51A and a second element back surface (not shown) facing opposite each other in the Z direction. A source electrode 51S and a gate electrode 51G are formed on the second element front surface 51A. A drain electrode 51D (see FIG. 5 ) is formed on the second element back surface. The drain electrode 51D is mounted on a second surface electrode 62B. The second switching element 51 has the same configuration as the first switching element 41. Therefore, detailed description of each component of the second switching element 51 will be omitted. Here, the second element front surface 51A is an example of the "front surface of the second switching element 41," and the second element back surface is an example of the "back surface of the second switching element 41."

[0087] 1, the source electrode 51S of the second switching element 51 and the plurality of second element surface electrodes 34B are individually and electrically connected by a plurality of wires W1. The source electrode 51S of the second switching element 51 and the third surface electrode 63B are electrically connected by a wire W2. The gate electrode 51G and the second surface electrode 62B are electrically connected by a wire W3.

[0088] In a plan view, the source electrode 41S of the first switching element 41 includes a portion facing the first light-emitting portion 33A in the Y direction. Wires W1 individually connected to the four first element surface electrodes 34A are connected to the end of the source electrode 41S of the first switching element 41 that is closer to the first light-emitting portion 33A in the Y direction, of both ends of the source electrode 41S of the first switching element 41. In a plan view, the source electrode 51S of the second switching element 51 includes a portion facing the second light-emitting portion 33B in the Y direction. Wires W1 individually connected to the four second element surface electrodes 34B are connected to the end of the source electrode 51S of the second switching element 51 that is closer to the second light-emitting portion 33B in the Y direction, of both ends of the source electrode 51S of the second switching element 51.

[0089] In one example, the four wires W1 individually connected to the four first element surface electrodes 34A are all equal in length. In another example, the four wires W1 individually connected to the four second element surface electrodes 34B are all equal in length. The number of wires W1 connected to each first element surface electrode 34A can be changed as desired. In one example, four wires W1 may be connected to each first element surface electrode 34A. In this case, 16 wires W1 are connected to the first light-emitting portion 33A, and 16 wires W1 are connected to the second light-emitting portion 33B.

[0090] Since the distance D1 between the semiconductor light-emitting element 30 and the first switching element 41 in the Y direction is equal to the distance D2 between the semiconductor light-emitting element 30 and the second switching element 51 in the Y direction, the total length of the four wires W1 individually connected to the four first element surface electrodes 34A and the total length of the four wires W1 individually connected to the four second element surface electrodes 34B can be adjusted to be equal to each other in a planar view.

[0091] 1 , in a plan view, the semiconductor light emitting element 30 and the second capacitor 52 are arranged spaced apart from each other in the Y direction. The second capacitor 52 is arranged on the opposite side of the second switching element 51 from the semiconductor light emitting element 30 in the Y direction. In other words, in a plan view, the second switching element 51 is arranged between the semiconductor light emitting element 30 and the second capacitor 52 in the Y direction.

[0092] A plurality of second capacitors 52 (six in the first embodiment) are provided. The plurality of second capacitors 52 are arranged spaced apart from one another in the X direction. Each second capacitor 52 is arranged to straddle the second surface electrode 62B and the fourth wiring portion 61D of the first surface electrode 61 in the Y direction. Each second capacitor 52 is mounted on the second surface electrode 62B and the fourth wiring portion 61D. More specifically, each second capacitor 52 includes a first electrode 52A and a second electrode 52B. Although not shown, the first electrode 52A is bonded to the second surface electrode 62B by a conductive bonding material SD. This electrically connects the first electrode 52A to the second surface electrode 62B. The second electrode 52B is bonded to the fourth wiring portion 61D by a conductive bonding material SD. This electrically connects the second electrode 52B to the fourth wiring portion 61D (first surface electrode 61). The arrangement of the second capacitors 52 is similar to the arrangement of the first capacitors 42, and therefore a detailed description thereof will be omitted.

[0093] The semiconductor light emitting device 10 further includes a first protection diode 101 and a second protection diode 102. The first protection diode 101 is a diode that protects the first light emitting portion 33A of the semiconductor light emitting element 30. The first protection diode 101 is disposed closer to the first substrate side surface 23 in the X direction than the semiconductor light emitting element 30, the first switching element 41, and the plurality of first capacitors 42. The first protection diode 101 is disposed on the opposite side of the semiconductor light emitting element 30 from the first switching element 41 in the Y direction. The first protection diode 101 is disposed in the same position as the first capacitor 42 in the Y direction. The first protection diode 101 is disposed so as to straddle the Y direction between the fourth surface electrode 64A and the fourth wiring portion 61D of the first surface electrode 61. The first protection diode 101 is mounted on the fourth surface electrode 64A and the first surface electrode 61. More specifically, the first protection diode 101 is individually bonded to the fourth surface electrode 64A and the first surface electrode 61 by a conductive bonding material SD.

[0094] The first protection diode 101 is connected in anti-parallel to the first light-emitting portion 33A. More specifically, the first protection diode 101 includes a first anode electrode 101A and a first cathode electrode 101B. The first protection diode 101 is arranged such that the first anode electrode 101A and the first cathode electrode 101B are at the same position in the X direction and spaced apart from each other in the Y direction. The first anode electrode 101A is bonded to the first surface electrode 61 by a conductive bonding material SD (not shown). The first anode electrode 101A is disposed on a fourth wiring portion 61D of the first surface electrode 61. This electrically connects the first anode electrode 101A to the back surface electrode 35 of the semiconductor light-emitting element 30 via the first surface electrode 61. The first cathode electrode 101B is bonded to the fourth surface electrode 64A by a conductive bonding material SD (not shown). The first cathode electrode 101B is disposed in the second opposing portion of the fourth surface electrode 64A, and is thereby electrically connected to the plurality of first element surface electrodes 34A corresponding to the first light-emitting portions 33A of the semiconductor light-emitting element 30 via the wire W2, the source electrode 41S of the first switching element 41, and the wire W1.

[0095] The second protection diode 102 is a diode that protects the second light-emitting portion 33B of the semiconductor light-emitting element 30. The second protection diode 102 is disposed closer to the second substrate side surface 24 in the X direction than the semiconductor light-emitting element 30, the second switching element 51, and the plurality of second capacitors 52. The second protection diode 102 is disposed on the opposite side of the semiconductor light-emitting element 30 from the second switching element 51 in the Y direction. The second protection diode 102 is disposed in the same position as the second capacitor 52 in the Y direction. The second protection diode 102 is disposed so as to straddle the Y-direction between the fourth surface electrode 64B and the fourth wiring portion 61D of the first surface electrode 61. The second protection diode 102 is mounted on the fourth surface electrode 64B and the first surface electrode 61. The mounting manner of the second protection diode 102 is the same as that of the first protection diode 101.

[0096] The second protection diode 102 is connected in anti-parallel to the second light-emitting portion 33B. More specifically, the second protection diode 102 includes a second anode electrode 102A and a second cathode electrode 102B. The second anode electrode 102A is bonded to the fourth wiring portion 61D of the first surface electrode 61 by a conductive bonding material SD. This electrically connects the second anode electrode 102A to the element back surface electrode 35 of the semiconductor light-emitting element 30 via the first surface electrode 61. The second cathode electrode 102B is bonded to a second opposing portion of the fourth surface electrode 64B by a conductive bonding material SD. This electrically connects the second cathode electrode 102B to a plurality of second element surface electrodes 34B corresponding to the second light-emitting portion 33B of the semiconductor light-emitting element 30 via the wire W2, the source electrode 51S of the second switching element 51, and the wire W1.

[0097] [Circuit Configuration of Semiconductor Light-Emitting Device] As shown in FIG. 5 , a light-emitting system 800 including the semiconductor light-emitting device 10 includes a DC power supply 801, a capacitor 802 connected in parallel with the DC power supply 801, a current-limiting resistor 803, backflow prevention diodes 804A and 804B, a gate driver IC 805, a pulse generator 806, and a control power supply 807.

[0098] A first terminal of the current limiting resistor 803 is electrically connected to the positive electrode of the DC power supply 801. The anodes of the reverse current prevention diodes 804A and 804B are electrically connected to the second terminal of the current limiting resistor 803. The cathode of the reverse current prevention diode 804A is electrically connected to the second back surface electrode 72A, and the cathode of the reverse current prevention diode 804B is electrically connected to the second back surface electrode 72B.

[0099] The gate driver IC 805 is electrically connected to the gate electrode 41G of the first switching element 41 and the gate electrode 51G of the second switching element 51 individually. That is, the gate driver IC 805 can individually control the first switching element 41 and the second switching element 51. In the first embodiment, an insulated gate driver is used as the gate driver IC 805. The gate driver IC 805 is electrically connected to the third rear surface electrodes 73A, 73B individually.

[0100] The pulse generator 806 and the control power supply 807 are electrically connected to the gate driver IC 805. The pulse generator 806 is configured to output pulse signals to the gate driver IC 805 for controlling the first switching element 41 and the second switching element 51. The control power supply 807 is a power supply for operating the gate driver IC 805. The control power supply 807 is configured to apply an operating voltage to the gate driver IC 805.

[0101] The negative electrode of the DC power supply 801, the capacitor 802, the pulse generator 806, and the negative electrode of the control power supply 807 are each electrically connected to the first back surface electrode 71. On the other hand, the negative electrode of the DC power supply 801, the capacitor 802, the pulse generator 806, and the negative electrode of the control power supply 807 are each connected to ground. Therefore, the first back surface electrode 71 is connected to ground.

[0102] In the semiconductor light-emitting device 10, the cathode of the reverse current prevention diode 804A is electrically connected to both the drain electrode 41D of the first switching element 41 and the first electrode 42A of the first capacitor 42 via the second back surface electrode 72A. The cathode of the reverse current prevention diode 804B is electrically connected to both the drain electrode 51D of the second switching element 51 and the first electrode 52A of the second capacitor 52 via the second back surface electrode 72B.

[0103] The source electrode 41S of the first switching element 41 is electrically connected to the first element surface electrode 34A (first anode electrode) corresponding to the first light-emitting portion 33A of the semiconductor light-emitting element 30 and the first cathode electrode 101B of the first protection diode 101. The second electrode 42B of the first capacitor 42, the element back surface electrode 35 (cathode) corresponding to the first light-emitting portion 33A of the semiconductor light-emitting element 30, and the first anode electrode 101A of the first protection diode 101 are each electrically connected to the first back surface electrode 71 via the first surface electrode 61.

[0104] The source electrode 51S of the second switching element 51 is electrically connected to the second element front surface electrode 34B (second anode electrode) corresponding to the second light-emitting portion 33B of the semiconductor light-emitting element 30 and the second cathode electrode 102B of the second protection diode 102. The second electrode 52B of the second capacitor 52, the element rear surface electrode 35 (cathode) corresponding to the second light-emitting portion 33B of the semiconductor light-emitting element 30, and the second anode electrode 102A of the second protection diode 102 are each electrically connected to the first rear surface electrode 71 via the first surface electrode 61. In this manner, the first surface electrode 61 constitutes ground wiring. The first rear surface electrode 71 electrically connected to the first surface electrode 61 constitutes a ground terminal.

[0105] In the semiconductor light-emitting device 10, when the first switching element 41 is in the OFF state, the first capacitor 42 is charged by the DC power supply 801. When the first switching element 41 is changed from the OFF state to the ON state, a current flows from the first capacitor 42 through the first switching element 41 to the first light-emitting unit 33A of the semiconductor light-emitting element 30. This causes pulsed laser light to be emitted from the first light-emitting unit 33A. When the second switching element 51 is in the OFF state, the second capacitor 52 is charged by the DC power supply 801. When the second switching element 51 is changed from the OFF state to the ON state, a current flows from the second capacitor 52 through the second switching element 51 to the second light-emitting unit 33B of the semiconductor light-emitting element 30. This causes pulsed laser light to be emitted from the second light-emitting unit 33B. In this way, the driving of the first light-emitting unit 33A is controlled by the first drive circuit 40 including the first switching element 41 and the first capacitor 42, and the driving of the second light-emitting unit 33B is controlled by the second drive circuit 50 including the second switching element 51 and the second capacitor 52. In other words, the first light-emitting unit 33A and the second light-emitting unit 33B are individually controlled by the first drive circuit 40 and the second drive circuit 50.

[0106] As an example, the first and second light-emitting units 33A and 33B are sequentially driven by the first and second drive circuits 40 and 50. In this case, the pulsed light emissions of the first and second light-emitting units 33A and 33B can be adjusted so that the pulse interval of the semiconductor light-emitting element 30 is shorter than in a semiconductor light-emitting device having, for example, a single light-emitting unit. This allows for an increase in the number of pulses per unit time. In addition, the alternating light emission of the first and second light-emitting units 33A and 33B can suppress heat generation in the semiconductor light-emitting element 30 compared to a semiconductor light-emitting device having a single light-emitting unit.

[0107] Furthermore, since each of the first light-emitting section 33A and the second light-emitting section 33B includes multiple (four in the first embodiment) light-emitting sections 33, the average output power of the laser light can be increased compared to a semiconductor light-emitting device having one light-emitting section.

[0108] [Operation] The operation of the semiconductor light emitting device 10 of the first embodiment will be described. In order to increase the output power of the semiconductor light emitting element, the semiconductor light emitting device 10 employs a semiconductor light emitting element 30 including a plurality of (eight in the first embodiment) light emitting portions 33. As the output power of the semiconductor light emitting element 30 increases, the amount of heat generated by the semiconductor light emitting element 30 also increases. For this reason, the semiconductor light emitting device 10 requires a structure for dissipating heat from the semiconductor light emitting element 30.

[0109] Therefore, in the semiconductor light emitting device 10 of the first embodiment, the semiconductor light emitting element 30 is mounted on a first surface electrode 61 formed on the substrate surface 21. In addition, a plurality of back surface electrodes 28B configured to mount the semiconductor light emitting device 10 are formed on the substrate back surface 22. Therefore, for example, as shown in Fig. 6, when the semiconductor light emitting device 10 is mounted on a circuit board 900, each back surface electrode 28B is joined to wiring 901 of the circuit board 900 by a conductive bonding material SDA. The conductive bonding material SDA may be any of solder paste, copper paste, gold paste, and silver paste.

[0110] 6 , the first back surface electrode 71 formed over most of the substrate back surface 22 is joined to the wiring 901 of the circuit board 900 by the conductive bonding material SDA. Therefore, heat from the semiconductor light emitting element 30 is transferred to the wiring 901 via the conductive bonding material SD joined to the element back surface electrode 35, the first surface electrode 61, the plurality of first vias 91A, the first back surface electrode 71, and the conductive bonding material SDA. Here, compared to a mounting structure on a circuit board using a plurality of leads in a semiconductor laser device with a CAN-type package structure, for example, the bonding area between the first back surface electrode 71, the conductive bonding material SDA, and the wiring 901 is larger, so that heat from the semiconductor light emitting element 30 is more likely to be transferred to the circuit board 900.

[0111] The semiconductor light-emitting device 10 may also be used in a laser system such as LiDAR (Light Detection and Ranging, Laser Imaging Detection and Ranging), which is an example of three-dimensional distance measurement. The semiconductor light-emitting device 10 may also be used in a laser system for two-dimensional distance measurement.

[0112] However, in LiDAR, in order to measure longer distances, a wider field of view and improved resolution are required. To meet such requirements, a driver circuit may be provided to individually drive the first light-emitting unit 33A and the second light-emitting unit 33B as channels. This allows the light emission timing of the first light-emitting unit 33A and the light emission timing of the second light-emitting unit 33B to be shifted, thereby shortening the pulse length of the laser light emitted by the semiconductor light-emitting element 30 and increasing the number of times the semiconductor light-emitting element 30 emits laser light per unit time.

[0113] However, if such a drive circuit is provided external to the semiconductor light-emitting device 10, the length of the first loop-shaped current path formed by the drive circuit and the first light-emitting unit 33A and the length of the second loop-shaped current path formed by the drive circuit and the second light-emitting unit 33B will both be long. As a result, the inductance caused by these current paths increases, making it difficult to further shorten the pulse width of the laser light emitted by the first light-emitting unit 33A and the second light-emitting unit 33B. In addition, as the lengths of the first and second current paths increase, the lengths of the first and second current paths become more variable. As a result, there is a risk that the pulse widths of the laser light emitted by the first and second light-emitting units 33A and 33B will vary from each other.

[0114] Therefore, the semiconductor light-emitting device 10 includes a first drive circuit 40 and a second drive circuit 50 that drive the first light-emitting portion 33A and the second light-emitting portion 33B, respectively. In other words, the semiconductor light-emitting device 10 incorporates the first drive circuit 40 and the second drive circuit 50. As shown in FIG. 7 , current flows through the first electrode 42A of the first capacitor 42, the second surface electrode 62A, the drain electrode 41D of the first switching element 41, the source electrode 41S, the wire W1, the first element surface electrode 34A, the element back surface electrode 35, the first surface electrode 61, the first intermediate electrode 81 of the surface-side intermediate electrode 28C, and the second electrode 42B of the first capacitor 42 in this order. In other words, a loop-shaped first current path is formed by the first light-emitting portion 33A and the first drive circuit 40. Although not shown, a loop-shaped second conduction path similar to the first current path is also formed by the second light-emitting portion 33B and the second drive circuit 50. Therefore, compared to a configuration in which the drive circuit is provided external to the semiconductor light-emitting device 10, the length of the loop-shaped first current path formed by the first light-emitting unit 33A and the first drive circuit 40 and the length of the loop-shaped second current path formed by the second light-emitting unit 33B and the second drive circuit 50 are both shorter. This reduces the inductance caused by the lengths of the first and second current paths. In addition, because the lengths of the first and second current paths are both short, the inductance variation caused by the variation in the lengths of the first and second current paths is reduced. This reduces the pulse width of the laser light emitted by the first light-emitting unit 33A and the second light-emitting unit 33B, and reduces the variation in the pulse width of the laser light emitted by the first light-emitting unit 33A and the second light-emitting unit 33B. In one example, the pulse width of the laser beam emitted by the first light-emitting unit 33A and the pulse width of the laser beam emitted by the second light-emitting unit 33B are each 4 ns or less. In another example, the absolute value of the variation between the pulse width of the laser beam emitted by the first light-emitting unit 33A and the pulse width of the laser beam emitted by the second light-emitting unit 33B is 10% or less.

[0115] [Effects] According to the semiconductor light emitting device 10 of the first embodiment, the following effects can be obtained. (1-1) A semiconductor light emitting device 10 includes a substrate 20 having a substrate surface 21 and a substrate back surface 22 facing opposite to the substrate surface 21; a plurality of front electrodes 28A formed on the substrate surface 21; a plurality of back surface electrodes 28B formed on the substrate back surface 22 and configured to mount the semiconductor light emitting device 10; a semiconductor light emitting element 30 including a first light emitting portion 33A and a second light emitting portion 33B; a first element front surface electrode 34A electrically connected to the first light emitting portion 33A; a second element front surface electrode 34B electrically connected to the second light emitting portion; and an element back surface electrode 35 electrically connected to both the first light emitting portion 33A and the second light emitting portion 33B; a first drive circuit 40 electrically connected to the first element front surface electrode 34A and driving the first light emitting portion 33A; and a second drive circuit 50 electrically connected to the second element front surface electrode 34B and driving the second light emitting portion 33B. The back surface electrodes 35 of the semiconductor light emitting elements 30, the first driving circuit 40, and the second driving circuit 50 are mounted on the plurality of front surface electrodes 28A.

[0116] With this configuration, the semiconductor light-emitting element 30 is mounted on the front electrode 28A, and the back electrode 28B is formed on the back surface 22 of the substrate. This facilitates transfer of heat from the semiconductor light-emitting element 30 to the outside of the semiconductor light-emitting device 10 via the front electrode 28A and the back electrode 28B. This prevents the temperature of the semiconductor light-emitting element 30 from becoming excessively high. In addition, since the semiconductor light-emitting device 10 includes the first drive circuit 40 and the second drive circuit 50, the first current path between the semiconductor light-emitting element 30 and the first drive circuit 40 and the second current path between the semiconductor light-emitting element 30 and the second drive circuit 50 are each shorter than in a configuration in which the first drive circuit 40 and the second drive circuit 50 are provided outside the semiconductor light-emitting device 10. This reduces the inductance due to the length of these current paths and reduces variations in inductance of the first current path and the second current path. As a result, the pulse width of the laser light emitted by the first light-emitting unit 33A and the pulse width of the laser light emitted by the second light-emitting unit 33B can be shortened, and the variation between the pulse width of the laser light emitted by the first light-emitting unit 33A and the pulse width of the laser light emitted by the second light-emitting unit 33B can be reduced.

[0117] (1-2) The first drive circuit 40 includes a first switching element 41 that controls the drive of the first light-emitting unit 33A and a first capacitor 42 that supplies current to the first light-emitting unit 33A. The second drive circuit 50 includes a second switching element 51 that controls the drive of the second light-emitting unit 33B and a second capacitor 52 that supplies current to the second light-emitting unit 33B.

[0118] According to this configuration, a loop-shaped first current path formed by the first light-emitting portion 33A, the first switching element 41, and the first capacitor 42 of the semiconductor light-emitting element 30 can be formed within the semiconductor light-emitting device 10. This shortens the length of the first current path compared to when both the first switching element 41 and the first capacitor 42 are provided externally to the semiconductor light-emitting device 10, thereby reducing inductance due to the length of the first current path. Furthermore, a loop-shaped second current path formed by the second light-emitting portion 33B, the second switching element 51, and the second capacitor 52 of the semiconductor light-emitting element 30 can be formed within the semiconductor light-emitting device 10. This shortens the length of the second current path compared to when both the second switching element 51 and the second capacitor 52 are provided externally to the semiconductor light-emitting device 10, thereby reducing inductance due to the length of the second current path. Additionally, because the lengths of both the first and second current paths are shortened, variation in the lengths of the first and second current paths can be reduced. Therefore, the variation in inductance between the first current path and the second current path can be reduced.

[0119] (1-3) In a plan view, the semiconductor light-emitting element 30 and the first capacitor 42 are arranged spaced apart from each other in the Y direction. In a plan view, the first switching element 41 is arranged between the semiconductor light-emitting element 30 and the first capacitor 42 in the Y direction. In a plan view, the semiconductor light-emitting element 30 and the second capacitor 52 are arranged spaced apart from each other in the Y direction. In a plan view, the second switching element 51 is arranged between the semiconductor light-emitting element 30 and the second capacitor 52 in the Y direction.

[0120] According to this configuration, the loop-shaped first current path formed by the first light-emitting unit 33A of the semiconductor light-emitting element 30, the first switching element 41, and the first capacitor 42 can be shortened compared to a configuration in which the first switching element 41 is arranged on the opposite side of the semiconductor light-emitting element 30 with respect to the first capacitor 42 in the Y direction. Also, the loop-shaped second current path formed by the second light-emitting unit 33B of the semiconductor light-emitting element 30, the second switching element 51, and the second capacitor 52 can be shortened compared to a configuration in which the second switching element 51 is arranged on the opposite side of the semiconductor light-emitting element 30 with respect to the second capacitor 52 in the Y direction.

[0121] (1-4) The distance D1 between the semiconductor light emitting element 30 and the first switching element 41 in the Y direction is equal to the distance D2 between the semiconductor light emitting element 30 and the second switching element 51 in the Y direction.

[0122] According to this configuration, the length of the current path between the semiconductor light emitting element 30 and the first switching element 41 is equal to the length of the current path between the semiconductor light emitting element 30 and the second switching element 51. This reduces variation in the length of the loop-shaped first current path formed by the first light emitting unit 33A of the semiconductor light emitting element 30, the first switching element 41, and the first capacitor 42, and the length of the loop-shaped second current path formed by the second light emitting unit 33B of the semiconductor light emitting element 30, the second switching element 51, and the second capacitor 52.

[0123] (1-5) There are provided a plurality of first capacitors 42 and a plurality of second capacitors 52. The plurality of first capacitors 42 are connected in parallel with one another. The plurality of second capacitors 52 are connected in parallel with one another.

[0124] According to this configuration, since the multiple first capacitors 42 are connected in parallel with each other, the total inductance of the multiple first capacitors 42 can be reduced below the inductance of each of the first capacitors 42. Furthermore, since the multiple second capacitors 52 are connected in parallel with each other, the total inductance of the multiple second capacitors 52 can be reduced below the inductance of each of the second capacitors 52.

[0125] (1-6) The multiple first capacitors 42 are arranged spaced apart from one another in the X direction. The multiple second capacitors 52 are arranged spaced apart from one another in the X direction. With this configuration, the arrangement direction (X direction) of the multiple first capacitors 42 is perpendicular to the arrangement direction (Y direction) of the semiconductor light-emitting element 30, the first switching element 41, and the first capacitor 42 in a planar view. Therefore, the length of the loop-shaped first current path formed by the first light-emitting unit 33A, the first switching element 41, and the first capacitor 42 of the semiconductor light-emitting element 30 can be shortened. The arrangement direction (X direction) of the multiple second capacitors 52 is perpendicular to the arrangement direction (Y direction) of the semiconductor light-emitting element 30, the second switching element 51, and the second capacitor 52 in a planar view. Therefore, the length of the loop-shaped second current path formed by the second light-emitting unit 33B, the second switching element 51, and the second capacitor 52 of the semiconductor light-emitting element 30 can be shortened.

[0126] (1-7) The semiconductor light emitting element 30 further includes a first protection diode 101 connected in anti-parallel to the first light emitting portion 33A and a second protection diode 102 connected in anti-parallel to the second light emitting portion 33B. With this configuration, the first protection diode 101 and the second protection diode 102 can prevent an excessive reverse bias from being applied to the first light emitting portion 33A and the second light emitting portion 33B due to the resonant current. Therefore, the peak optical output of the semiconductor light emitting element 30 can be increased.

[0127] (1-8) The first protection diode 101 is disposed on the opposite side of the first switching element 41 from the semiconductor light emitting element 30 in the Y direction. The second protection diode 102 is disposed on the opposite side of the second switching element 51 from the semiconductor light emitting element 30 in the Y direction. The first protection diode 101 is disposed spaced apart from the first capacitor 42 in the X direction. The second protection diode 102 is disposed spaced apart from the second capacitor 52 in the X direction.

[0128] According to this configuration, the length of the loop-shaped first current path formed by the semiconductor light emitting element 30, the first switching element 41, and the first capacitor 42 can be shortened compared to a configuration in which the first protection diode 101 is arranged between the semiconductor light emitting element 30 and the first switching element 41 or between the first switching element 41 and the first capacitor 42. Furthermore, the length of the loop-shaped second current path formed by the semiconductor light emitting element 30, the second switching element 51, and the second capacitor 52 can be shortened compared to a configuration in which the second protection diode 102 is arranged between the semiconductor light emitting element 30 and the second switching element 51 or between the second switching element 51 and the second capacitor 52.

[0129] (1-9) In plan view, the area of ​​the first surface electrode 61 is larger than the areas of the second surface electrodes 62A and 62B, the third surface electrodes 63A and 63B, and the fourth surface electrodes 64A and 64B.

[0130] According to this configuration, heat from the semiconductor light emitting element 30 mounted on the first surface electrode 61 is easily transferred to the first surface electrode 61. Therefore, the temperature of the semiconductor light emitting element 30 can be prevented from becoming excessively high.

[0131] (1-10) In plan view, the area of ​​the first surface electrode 61 is larger than the total area of ​​the second surface electrodes 62A and 62B, the third surface electrodes 63A and 63B, and the fourth surface electrodes 64A and 64B.

[0132] According to this configuration, heat from the semiconductor light emitting element 30 mounted on the first surface electrode 61 can be more easily transferred to the first surface electrode 61. Therefore, the temperature of the semiconductor light emitting element 30 can be further prevented from becoming excessively high.

[0133] (1-11) In plan view, the area of ​​the first back surface electrode 71 is larger than the area of ​​each of the second back surface electrodes 72A and 72B, the third back surface electrodes 73A and 73B, and the fourth back surface electrodes 74A and 74B.

[0134] According to this configuration, the heat capacity of the first back surface electrode 71 is increased, and therefore heat from the semiconductor light emitting element 30 is more likely to transfer to the first back surface electrode 71. In addition, when the semiconductor light emitting device 10 is mounted on the circuit board 900, the bonding area between the first back surface electrode 71 and the circuit board 900 is increased, and therefore heat from the semiconductor light emitting element 30 is more likely to transfer to the circuit board 900 via the first back surface electrode 71. Therefore, it is possible to prevent the temperature of the semiconductor light emitting element 30 from becoming excessively high.

[0135] (1-12) In plan view, the area of ​​the first back surface electrode 71 is larger than the total area of ​​the second back surface electrodes 72A and 72B, the third back surface electrodes 73A and 73B, and the fourth back surface electrodes 74A and 74B.

[0136] According to this configuration, the heat capacity of the first back surface electrode 71 is increased, which makes it easier for heat from the semiconductor light emitting element 30 to transfer to the first back surface electrode 71. In addition, when the semiconductor light emitting device 10 is mounted on the circuit board 900, the bonding area between the first back surface electrode 71 and the circuit board 900 is increased, which makes it easier for heat from the semiconductor light emitting element 30 to transfer to the circuit board 900 via the first back surface electrode 71. Therefore, it is possible to further prevent the temperature of the semiconductor light emitting element 30 from becoming excessively high.

[0137] (1-13) In plan view, the area of ​​the first intermediate electrode 81 is larger than the areas of the second intermediate electrodes 82A and 82B, the third intermediate electrodes 83A and 83B, and the fourth intermediate electrodes 84A and 84B.

[0138] According to this configuration, the heat capacity of the first intermediate electrode 81 is increased, and therefore heat from the semiconductor light emitting element 30 is more easily transferred to the first intermediate electrode 81. Therefore, the temperature of the semiconductor light emitting element 30 can be prevented from becoming excessively high.

[0139] (1-14) In plan view, the area of ​​the first intermediate electrode 81 is larger than the total area of ​​the second intermediate electrodes 82A and 82B, the third intermediate electrodes 83A and 83B, and the fourth intermediate electrodes 84A and 84B.

[0140] According to this configuration, the heat capacity of the first intermediate electrode 81 is increased, and therefore heat from the semiconductor light emitting element 30 is more easily transferred to the first intermediate electrode 81. Therefore, the temperature of the semiconductor light emitting element 30 can be further prevented from becoming excessively high.

[0141] (1-15) The element back surface electrode 35 of the semiconductor light emitting element 30 is electrically connected to the first surface electrode 61. The drain electrode 41D of the first switching element 41 is electrically connected to the second surface electrode 62A. The source electrode 41S of the first switching element 41 is electrically connected to the first element surface electrode 34A. The first electrode 42A of the first capacitor 42 is electrically connected to the second surface electrode 62A. The second electrode 42B of the first capacitor 42 is electrically connected to the first surface electrode 61. The drain electrode 51D of the second switching element 51 is electrically connected to the second surface electrode 62B. The source electrode 51S of the second switching element 51 is electrically connected to the second element surface electrode 34B. The first electrode 52A of the second capacitor 52 is electrically connected to the second surface electrode 62B. The second electrode 52B of the second capacitor 52 is electrically connected to the first surface electrode 61. The first intermediate electrode 81 is electrically connected to the first surface electrode 61.

[0142] With this configuration, a portion of the loop of the first current path, through which current flows in the order of the first electrode 42A of the first capacitor 42, the drain electrode 41D and source electrode 41S of the first switching element 41, the first element front surface electrode 34A and back surface electrode 35 of the semiconductor light-emitting element 30, and the second electrode 42B of the first capacitor 42, is defined by the first intermediate electrode 81. This reduces the loop area of ​​the first current path, thereby reducing the inductance of the first current path. Furthermore, a portion of the loop of the second current path, through which current flows in the order of the first electrode 52A of the second capacitor 52, the drain electrode 51D and source electrode 51S of the second switching element 51, the second element front surface electrode 34B and back surface electrode 35 of the semiconductor light-emitting element 30, and the second electrode 52B of the second capacitor 52, is defined by the first intermediate electrode 81. This reduces the loop area of ​​the second current path, thereby reducing the inductance of the second current path.

[0143] (1-16) The multiple first vias 91A are arranged at positions that overlap the semiconductor light emitting element 30 in a plan view. With this configuration, heat from the semiconductor light emitting element 30 is more likely to transfer to the first intermediate electrode 81 and the first back surface electrode 71. Therefore, it is possible to prevent the temperature of the semiconductor light emitting element 30 from becoming excessively high.

[0144] (1-17) When viewed from the Y direction, the region where the plurality of first vias 91B are formed is disposed at a position that overlaps the region where the plurality of first vias 91A are formed. With this configuration, of the loop of the first current path through which current flows in this order, the first electrode 42A of the first capacitor 42, the drain electrode 41D and source electrode 41S of the first switching element 41, the first element front surface electrode 34A and element back surface electrode 35 of the semiconductor light emitting element 30, and the second electrode 42B of the first capacitor 42, the path through the first intermediate electrode 81 is a path along the Y direction. Therefore, the area of ​​the loop of the first current path can be reduced, thereby reducing the inductance of the first current path. Furthermore, of the loop of the second current path in which current flows in this order through the first electrode 52A of the second capacitor 52, the drain electrode 51D and source electrode 51S of the second switching element 51, the second element front surface electrode 34B and back surface electrode 35 of the semiconductor light emitting element 30, and the second electrode 52B of the second capacitor 52, the path through the first intermediate electrode 81 is a path along the Y direction. Therefore, the area of ​​the loop of the second current path can be reduced, and the inductance of the second current path can be reduced.

[0145] (1-18) The second surface electrode 62A includes a narrow portion 62AA and a wide portion 62AB. The first switching element 41 is mounted on the narrow portion 62AA. Both the third surface electrode 63A and the fourth surface electrode 64A include a portion located adjacent to the narrow portion 62AA of the second surface electrode 62A in the X direction. The second surface electrode 62B includes a narrow portion 62BA and a wide portion 62BB. The second switching element 51 is mounted on the narrow portion 62BA. Both the third surface electrode 63B and the fourth surface electrode 64B include a portion located adjacent to the narrow portion 62BA of the second surface electrode 62B in the X direction.

[0146] This configuration makes it possible to shorten the length of the wire W2 connecting the source electrode 41S and the fourth surface electrode 64A of the first switching element 41 and the length of the wire W3 connecting the gate electrode 41G and the third surface electrode 63A of the first switching element 41. Also, it is possible to shorten the length of the wire W2 connecting the source electrode 51S and the fourth surface electrode 64B of the second switching element 51 and the length of the wire W3 connecting the gate electrode 51G and the third surface electrode 63B of the second switching element 51.

[0147] (1-19) The first switching element 41 is disposed at a position overlapping the first light-emitting portion 33A of the semiconductor light-emitting element 30 when viewed from the Y direction. The second switching element 51 is disposed at a position overlapping the second light-emitting portion 33B of the semiconductor light-emitting element 30 when viewed from the Y direction.

[0148] According to this configuration, the distance between the first switching element 41 and the semiconductor light emitting element 30 can be shortened compared to a configuration in which the first switching element 41 is disposed at a position offset in the X direction with respect to the semiconductor light emitting element 30. Therefore, when the source electrode 41S of the first switching element 41 and the first element surface electrode 34A of the semiconductor light emitting element 30 are connected by a wire W1, the length of the wire W1 can be shortened. Compared to a configuration in which the second switching element 51 is disposed at a position offset in the X direction with respect to the semiconductor light emitting element 30, the distance between the second switching element 51 and the semiconductor light emitting element 30 can be shortened. Therefore, when the source electrode 51S of the second switching element 51 and the second element surface electrode 34B of the semiconductor light emitting element 30 are connected by a wire W1, the length of the wire W1 can be shortened.

[0149] (1-20) Vertical transistors of the same configuration are used for the first switching element 41 and the second switching element 51. With this configuration, only one type of switching element is used in the semiconductor light emitting device 10, which reduces the manufacturing cost of the semiconductor light emitting device 10 compared to when two types of switching elements are used.

[0150] 8 to 11, a semiconductor light emitting device 10 according to a second embodiment will be described. The semiconductor light emitting device 10 according to the second embodiment differs from the semiconductor light emitting device 10 according to the first embodiment in the number of light emitting units that are individually controlled. Below, differences from the first embodiment will be described in detail, and components that are common to the first embodiment will be assigned the same reference numerals, and their description may be omitted.

[0151] Fig. 8 shows a schematic planar structure of the semiconductor light emitting device 10 of the second embodiment. Fig. 9 shows a schematic back surface structure of the semiconductor light emitting device 10 of Fig. 8. Fig. 10 shows a schematic planar structure of the front surface side intermediate electrode 28C of the semiconductor light emitting device 10 of Fig. 8. Fig. 11 shows a schematic circuit configuration of a light emitting system 800 including the semiconductor light emitting device 10 of the second embodiment.

[0152] As shown in FIG. 8 , the semiconductor light emitting element 30 of the second embodiment includes first to fourth light emitting portions 33A to 33D, each including two light emitting portions 33 out of eight light emitting portions 33, and first to fourth element surface electrodes 34A to 34D provided corresponding to the first to fourth light emitting portions 33A to 33D. The first element surface electrode 34A is provided on the first light emitting portion 33A, the second element surface electrode 34B is provided on the second light emitting portion 33B, the third element surface electrode 34C is provided on the third light emitting portion 33C, and the fourth element surface electrode 34D is provided on the fourth light emitting portion 33D. The number of each of the first to fourth element surface electrodes 34A to 34D is set according to the number of the first to fourth light emitting portions 33A to 33D. In the second embodiment, since the number of each of the first to fourth light emitting portions 33A to 33D is two, the number of each of the first to fourth element surface electrodes 34A to 34D is two. The first element surface electrode 34A is an example of a "first anode electrode," the second element surface electrode 34B is an example of a "second anode electrode," the third element surface electrode 34C is an example of a "third anode electrode," and the fourth element surface electrode 34D is an example of a "fourth anode electrode."

[0153] The semiconductor light-emitting device 10 includes a configuration for individually controlling the driving of the first to fourth light-emitting portions 33A to 33D. More specifically, the semiconductor light-emitting device 10 includes a first drive circuit 40 for driving the first light-emitting portion 33A, a second drive circuit 50 for driving the second light-emitting portion 33B, a third drive circuit 110 for driving the third light-emitting portion 33C, and a fourth drive circuit 120 for driving the fourth light-emitting portion 33D. The first drive circuit 40 is electrically connected to the first element surface electrode 34A of the first light-emitting portion 33A. The second drive circuit 50 is electrically connected to the second element surface electrode 34B of the second light-emitting portion 33B. The third drive circuit 110 is electrically connected to the third element surface electrode 34C of the third light-emitting portion 33C. The fourth drive circuit 120 is electrically connected to the fourth element surface electrode 34D of the fourth light-emitting portion 33D.

[0154] The first drive circuit 40 includes a first switching element 41 and a first capacitor 42, as in the first embodiment. The second drive circuit 50 includes a second switching element 51 and a second capacitor 52, as in the first embodiment.

[0155] The third drive circuit 110 includes a third switching element 111 that controls the driving of the third light-emitting unit 33 C, and a third capacitor 112 that supplies current to the third light-emitting unit 33 C. The third switching element 111 and the third capacitor 112 are arranged apart from the semiconductor light-emitting element 30.

[0156] The fourth drive circuit 120 includes a fourth switching element 121 that controls the driving of the fourth light-emitting unit 33D and a fourth capacitor 122 that supplies current to the fourth light-emitting unit 33D. The fourth switching element 121 and the fourth capacitor 122 are arranged apart from the semiconductor light-emitting element 30.

[0157] Due to these changes in the configuration of the drive circuit, the configuration of the substrate 20 differs from that of the first embodiment. The configuration of the substrate 20 in the second embodiment will be described below. The substrate 20 includes first surface electrodes 131A, 131B, second surface electrodes 132A to 132D, third surface electrodes 133A to 133D, and fourth surface electrodes 134A to 134D as surface electrodes 28A formed on the substrate surface 21. The first surface electrodes 131A, 131B, second surface electrodes 132A to 132D, third surface electrodes 133A to 133D, and fourth surface electrodes 134A to 134D are arranged at a distance from one another.

[0158] The first surface electrode 131A is a surface electrode on which the semiconductor light emitting element 30 is mounted. The first surface electrode 131A is disposed near the third substrate side surface 25 of the substrate surface 21 and at the center of the substrate surface 21 in the X direction in a plan view. The first surface electrode 131A is formed in a rectangular shape with the X direction as the longitudinal direction and the Y direction as the lateral direction in a plan view. In one example, the first surface electrode 131A has an axisymmetric shape with respect to the imaginary center line VC.

[0159] The first surface electrode 131B is a surface electrode that constitutes a ground wiring electrically connected to a ground terminal. The first surface electrode 131B is formed in a substantially U-shape on the outer periphery of the substrate surface 21. The first surface electrode 131B includes a first wiring portion 131BA formed along the first substrate side surface 23, a second wiring portion 131BB formed along the second substrate side surface 24, and a third wiring portion 131BC formed along the fourth substrate side surface 26. In one example, the first wiring portion 131BA, the second wiring portion 131BB, and the third wiring portion 131BC are integrated. In one example, the first surface electrode 131B has an axisymmetric shape with respect to the imaginary center line VC.

[0160] In a plan view, the first surface electrode 131B is formed to surround the first surface electrode 131A, the second surface electrodes 132A to 132D, the third surface electrodes 133A to 133D, and the fourth surface electrodes 134A to 134D. The area of ​​the first surface electrode 131B is larger than the area of ​​each of the first surface electrode 131A, the second surface electrodes 132A to 132D, the third surface electrodes 133A to 133D, and the fourth surface electrodes 134A to 134D.

[0161] The second surface electrode 132A, the third surface electrode 133A, the fourth surface electrode 134A, and the first surface electrode 131B are electrodes that electrically connect to the first drive circuit 40. The second surface electrode 132B, the third surface electrode 133B, the fourth surface electrode 134B, and the first surface electrode 131B are electrodes that electrically connect to the second drive circuit 50. The second surface electrode 132C, the third surface electrode 133C, the fourth surface electrode 134C, and the first surface electrode 131B are electrodes that electrically connect to the third drive circuit 110. The second surface electrode 132D, the third surface electrode 133D, the fourth surface electrode 134D, and the first surface electrode 131B are electrodes that electrically connect to the fourth drive circuit 120.

[0162] The second surface electrodes 132A and 132B are arranged adjacent to each other on either side of the imaginary center line VC in the X direction. The second surface electrodes 132A and 132B are formed in a substantially L-shape in a plan view. In one example, the second surface electrodes 132A and 132B are in a line-symmetric relationship with respect to the imaginary center line VC.

[0163] The second surface electrodes 132A and 132B are located between the first surface electrode 131A and the third wiring portion 131BC of the first surface electrode 131B in the Y direction. Therefore, the second surface electrodes 132A and 132B are arranged at positions overlapping with the first surface electrode 131A when viewed from the Y direction.

[0164] The second surface electrodes 132A, 132B include a narrow portion, a wide portion, and a connecting portion. The narrow portion and the wide portion of the second surface electrodes 132A, 132B are arranged at a distance from each other in the Y direction. The connecting portion connects the narrow portion and the wide portion between them in the Y direction.

[0165] The wide portion constitutes the end of each of the second surface electrodes 132A and 132B in the Y direction that is closer to the third wiring portion 131BC. The narrow portion includes the end of each of the second surface electrodes 132A and 132B in the Y direction that is closer to the first surface electrode 131A. In the example shown in FIG. 8 , the dimension of the narrow portion in the X direction is approximately half the dimension of the wide portion in the X direction. The connecting portion is a portion whose dimension in the X direction gradually increases from the narrow portion toward the wide portion.

[0166] The second surface electrode 132C and the second surface electrode 132D are disposed on both sides of the first surface electrode 131A in the X direction. The second surface electrode 132C is disposed closer to the first substrate side surface 23 than the first surface electrode 131A, and the second surface electrode 132D is disposed closer to the second substrate side surface 24 than the first surface electrode 131A. In one example, the second surface electrodes 132C and 132D are in an axisymmetric relationship with respect to the imaginary center line VC.

[0167] In one example, the size and shape of the second surface electrode 132C are the same as those of the second surface electrode 132B. The second surface electrode 132C has a shape obtained by rotating the second surface electrode 132B by 90 degrees counterclockwise. Therefore, the narrow and wide portions of the second surface electrode 132C are arranged at a distance in the X direction. The narrow portion of the second surface electrode 132C is disposed near the first surface electrode 131A in the X direction. The wide portion of the second surface electrode 132C is disposed near the first wiring portion 131BA in the X direction. The connecting portion of the second surface electrode 132C connects the narrow portion and the wide portion between them in the X direction.

[0168] In one example, the size and shape of the second surface electrode 132D are the same as those of the second surface electrode 132A. The second surface electrode 132D has a shape obtained by rotating the second surface electrode 132A by 90 degrees clockwise. Therefore, the narrow and wide portions of the second surface electrode 132D are arranged at a distance in the X direction. The narrow portion of the second surface electrode 132D is disposed near the first surface electrode 131A in the X direction. The wide portion of the second surface electrode 132D is disposed near the second wiring portion 131BB in the X direction. The connecting portion of the second surface electrode 132D connects the narrow portion and the wide portion between them in the X direction.

[0169] The third surface electrode 133A is disposed closer to the first substrate side surface 23 than the narrow portion of the second surface electrode 132A in the X direction. The third surface electrode 133A is disposed between the connecting portion of the first surface electrode 131A and the second surface electrode 132A in the Y direction.

[0170] The third surface electrode 133B is disposed closer to the second substrate side surface 24 than the narrow portion of the second surface electrode 132B in the X direction. The third surface electrode 133B is disposed between the connecting portion of the first surface electrode 131A and the second surface electrode 132B in the Y direction. In one example, the third surface electrodes 133A and 133B are in an axisymmetric relationship with respect to the imaginary center line VC.

[0171] The third surface electrode 133C is arranged closer to the fourth substrate side surface 26 than the narrow portion of the second surface electrode 132C in the Y direction. The third surface electrode 133C is arranged between the connecting portion of the first surface electrode 131A and the second surface electrode 132C in the X direction. In one example, the third surface electrode 133C is arranged closer to the fourth substrate side surface 26 than the first surface electrode 131A in the Y direction. In one example, the size and shape of the third surface electrode 133C are the same as those of the third surface electrode 133B. The third surface electrode 133C has a shape obtained by rotating the third surface electrode 133B by 90 degrees counterclockwise.

[0172] The third surface electrode 133D is arranged closer to the fourth substrate side surface 26 than the narrow portion of the second surface electrode 132D in the Y direction. The third surface electrode 133D is arranged between the connecting portion of the first surface electrode 131A and the second surface electrode 132D in the X direction. In one example, the third surface electrode 133D is arranged closer to the fourth substrate side surface 26 than the first surface electrode 131A in the Y direction. In one example, the size and shape of the third surface electrode 133D are the same as those of the third surface electrode 133A. The third surface electrode 133D has a shape obtained by rotating the third surface electrode 133A by 90 degrees clockwise.

[0173] The fourth surface electrode 134A is disposed closer to the first substrate side surface 23 in the X direction than the second surface electrode 132A. The fourth surface electrode 134A is disposed between the first surface electrode 131A and the third wiring portion 131BC in the Y direction. The fourth surface electrode 134A includes a first opposing portion opposing the narrow portion of the second surface electrode 132A in the X direction and a second opposing portion opposing the third wiring portion 131BC in the Y direction. The fourth surface electrode 134A further includes a first connecting portion connected to the first opposing portion and a second connecting portion connected to the second opposing portion. The first opposing portion is disposed between the first surface electrode 131A and the third surface electrode 133A in the Y direction. In other words, the third surface electrode 133A is disposed between the first opposing portion and the connecting portion of the second surface electrode 132A in the Y direction. The first connecting portion and the second connecting portion are connected to each other. The first connecting portion extends obliquely toward the first substrate side surface 23 and the fourth substrate side surface 26 as it approaches the second connecting portion. The second connecting portion is a portion whose dimension in the X direction gradually increases as it approaches the second opposing portion.

[0174] The fourth surface electrode 134B is disposed closer to the second substrate side surface 24 than the second surface electrode 132B in the X direction. The fourth surface electrode 134B is disposed between the first surface electrode 131A and the third wiring portion 131BC in the Y direction. The fourth surface electrodes 134A and 134B are in an axisymmetric relationship with respect to the imaginary center line VC. Therefore, the first opposing portion of the fourth surface electrode 134B is disposed between the first surface electrode 131A and the third surface electrode 133B in the Y direction. In other words, the third surface electrode 133B is disposed between the first opposing portion and the connecting portion of the second surface electrode 132B in the Y direction.

[0175] The fourth surface electrode 134C is disposed adjacent to the fourth surface electrode 134A in the X and Y directions. The fourth surface electrode 134C is disposed between the second surface electrode 132C and the third wiring portion 131BC in the Y direction. The fourth surface electrode 134C is disposed between the first surface electrode 131A and the first wiring portion 131BA in the X direction. In one example, the size and shape of the fourth surface electrode 134C are the same as those of the fourth surface electrode 134B. The fourth surface electrode 134C has a shape obtained by rotating the fourth surface electrode 134B by 90 degrees counterclockwise. Therefore, the first opposing portion of the fourth surface electrode 134C faces the narrow portion of the second surface electrode 132C in the Y direction. The second opposing portion of the fourth surface electrode 134C faces the first wiring portion 131BA in the X direction.

[0176] The fourth surface electrode 134D is disposed adjacent to the fourth surface electrode 134B in the X and Y directions. The fourth surface electrode 134D is disposed between the second surface electrode 132D and the third wiring portion 131BC in the Y direction. The fourth surface electrode 134D is disposed between the first surface electrode 131A and the second wiring portion 131BB in the X direction. In one example, the size and shape of the fourth surface electrode 134D are the same as those of the fourth surface electrode 134A. The fourth surface electrode 134D has a shape obtained by rotating the fourth surface electrode 134A by 90 degrees clockwise. Therefore, the first opposing portion of the fourth surface electrode 134D faces the narrow portion of the second surface electrode 132D in the Y direction. The second opposing portion of the fourth surface electrode 134D faces the second wiring portion 131BB in the X direction.

[0177] 9, the back surface electrode 28B includes a first back surface electrode 141, second back surface electrodes 142A to 142D, third back surface electrodes 143A to 143D, and fourth back surface electrodes 144A to 144D. The first back surface electrode 141, second back surface electrodes 142A to 142D, third back surface electrodes 143A to 143D, and fourth back surface electrodes 144A to 144D are arranged spaced apart from one another.

[0178] The first back surface electrode 141 is formed in a substantially T-shape in plan view. The first back surface electrode 141 includes a first wide portion 141A, a second wide portion 141B, and a narrow portion 141C. In one example, the first wide portion 141A, the second wide portion 141B, and the narrow portion 141C are integrated. In one example, the first back surface electrode 141 has an axisymmetric shape with respect to the imaginary center line VC.

[0179] The first wide portion 141A and the second wide portion 141B are arranged closer to the third substrate side surface 25 than the center of the substrate back surface 22 in the Y direction. The first wide portion 141A is arranged closer to the third substrate side surface 25 than the second wide portion 141B. The first wide portion 141A is formed over substantially the entire substrate back surface 22 in the X direction. The X direction dimension of the second wide portion 141B is smaller than the X direction dimension of the first wide portion 141A. In one example, the Y direction dimension of the second wide portion 141B is equal to the Y direction dimension of the first wide portion 141A. The narrow portion 141C extends in the Y direction at the center of the substrate back surface 22 in the X direction. The tip of the narrow portion 141C is arranged in a position adjacent to the fourth substrate side surface 26 in the Y direction in a plan view.

[0180] In a plan view, the area of ​​the first back surface electrode 141 is larger than the area of ​​each of the second back surface electrodes 142A to 142D, the third back surface electrodes 143A to 143D, and the fourth back surface electrodes 144A to 144D. In one example, the area of ​​the first back surface electrode 141 is equal to or larger than the total area of ​​the second back surface electrodes 142A to 142D, the third back surface electrodes 143A to 143D, and the fourth back surface electrodes 144A to 144D.

[0181] The first back surface electrode 141, the second back surface electrode 142A, the third back surface electrode 143A, and the fourth back surface electrode 144A are electrodes electrically connected to the first drive circuit 40 (see FIG. 8). The first back surface electrode 141, the second back surface electrode 142B, the third back surface electrode 143B, and the fourth back surface electrode 144B are electrodes electrically connected to the second drive circuit 50 (see FIG. 8). The first back surface electrode 141, the second back surface electrode 142C, the third back surface electrode 143C, and the fourth back surface electrode 144C are electrodes electrically connected to the third drive circuit 110 (see FIG. 8). The first back surface electrode 141, the second back surface electrode 142D, the third back surface electrode 143D, and the fourth back surface electrode 144D are electrodes electrically connected to the fourth drive circuit 120 (see FIG. 8).

[0182] The second back surface electrodes 142A and 142B are distributed on both sides of the narrow width portion 141C of the first back surface electrode 141 in the X direction. The third back surface electrodes 143A and 143B are distributed on both sides of the narrow width portion 141C of the first back surface electrode 141 in the X direction. The fourth back surface electrodes 144A and 144B are distributed on both sides of the narrow width portion 141C of the first back surface electrode 141 in the X direction. The second back surface electrodes 142A, 143A, and 144A are each disposed closer to the first substrate side surface 23 than the narrow width portion 141C. The second back surface electrodes 142B, 143B, and 144B are each disposed closer to the second substrate side surface 24 than the narrow width portion 141C. The second back surface electrode 142A is disposed closer to the narrow portion 141C in the X direction than the third back surface electrode 143A and the fourth back surface electrode 144A. The fourth back surface electrode 144A is disposed farther from the narrow portion 141C in the X direction than the second back surface electrode 142A and the third back surface electrode 143A. The second back surface electrode 142B is disposed closer to the narrow portion 141C in the X direction than the third back surface electrode 143B and the fourth back surface electrode 144B. The fourth back surface electrode 144B is disposed farther from the narrow portion 141C in the X direction than the second back surface electrode 142B and the third back surface electrode 143B.

[0183] In one example, the second back surface electrodes 142A and 142B are line-symmetric with respect to the imaginary center line VC. The second back surface electrodes 142A and 142B extend in the Y direction. In one example, the third back surface electrodes 143A and 143B are line-symmetric with respect to the imaginary center line VC. The third back surface electrode 143A extends in the Y direction and is formed to surround the second back surface electrode 142A from the first substrate side surface 23 side in the X direction and the third substrate side surface 25 side in the Y direction. The third back surface electrode 143B extends in the Y direction and is formed to surround the second back surface electrode 142B from the second substrate side surface 24 side in the X direction and the third substrate side surface 25 side in the Y direction. Therefore, the ends of the third back surface electrodes 143A and 143B closer to the third substrate side surface 25 in the Y direction are positioned adjacent to the second wide portion 141B in the Y direction.

[0184] 9 , the tip of the narrow portion 141C of the first back-surface electrode 141, the ends of the second back-surface electrodes 142A and 142B near the fourth substrate side surface 26 in the Y direction, the ends of the third back-surface electrodes 143A and 143B near the fourth substrate side surface 26 in the Y direction, and the ends of the fourth back-surface electrodes 144A and 144B near the fourth substrate side surface 26 in the Y direction are all located at the same position in the Y direction and adjacent to the fourth substrate side surface 26.

[0185] The second back surface electrodes 142C and 142D are distributed on both sides of the second wide portion 141B of the first back surface electrode 141 in the X direction. The third back surface electrodes 143C and 143D are distributed on both sides of the second wide portion 141B of the first back surface electrode 141 in the X direction. The fourth back surface electrodes 144C and 144D are distributed on both sides of the second wide portion 141B of the first back surface electrode 141 in the X direction. The second back surface electrodes 142C, 143C, and 144C are each disposed closer to the first substrate side surface 23 than the second wide portion 141B. The second back surface electrodes 142D, 143D, and 144D are each disposed closer to the second substrate side surface 24 than the second wide portion 141B.

[0186] The second, third, and fourth back-surface electrodes 142C, 143C, and 144C are arranged at a distance from one another in the Y direction. The second back-surface electrode 142C is disposed closer to the first wide portion 141A in the Y direction than the third and fourth back-surface electrodes 143C and 144C. The fourth back-surface electrode 144C is disposed at a position farther from the first wide portion 141A in the Y direction than the second and third back-surface electrodes 142C and 143C.

[0187] The second, third, and fourth back-surface electrodes 142D, 143D, and 144D are arranged spaced apart from one another in the Y direction. The second back-surface electrode 142D is disposed closer to the first wide portion 141A in the Y direction than the third and fourth back-surface electrodes 143D and 144D. The fourth back-surface electrode 144D is disposed at a position farther from the first wide portion 141A in the Y direction than the second and third back-surface electrodes 142D and 143D.

[0188] In one example, the second back surface electrodes 142C and 142D are in an axisymmetric relationship with respect to the imaginary center line VC. The second back surface electrodes 142C and 142D extend in the X direction. The second back surface electrode 142C has a shape obtained by rotating the second back surface electrode 142B by 90 degrees clockwise. The second back surface electrode 142D has a shape obtained by rotating the second back surface electrode 142A by 90 degrees counterclockwise.

[0189] In one example, the third back-surface electrodes 143C and 143D are symmetrical with respect to the imaginary center line VC. The third back-surface electrode 143C extends in the Y direction and is formed to surround the second back-surface electrode 142C from the fourth substrate side surface 26 side in the Y direction and the second wide portion 141B side in the X direction. The third back-surface electrode 143D extends in the Y direction and is formed to surround the second back-surface electrode 142D from the fourth substrate side surface 26 side in the Y direction and the second wide portion 141B side in the X direction. Therefore, the ends of the third back-surface electrodes 143C and 143D closer to the second wide portion 141B in the X direction are positioned adjacent to the second wide portion 141B in the X direction.

[0190] 9 , of both ends in the X direction of the first wide portion 141A of the first back surface electrode 141, the end closer to the first substrate side surface 23 in the X direction of the first wide portion 141A of the first back surface electrode 141, the end closer to the first substrate side surface 23 in the X direction of the second back surface electrode 142C, the end closer to the first substrate side surface 23 in the X direction of the third back surface electrode 143C, and the end closer to the first substrate side surface 23 in the X direction of the fourth back surface electrode 144C are arranged at the same position in the X direction and adjacent to the first substrate side surface 23. Furthermore, of the two X-direction ends of the first wide portion 141A of the first back surface electrode 141, the end closer to the second substrate side surface 24, the end closer to the second substrate side surface 24 in the X-direction of the second back surface electrode 142D, the end closer to the second substrate side surface 24 in the X-direction of the third back surface electrode 143D, and the end closer to the second substrate side surface 24 in the X-direction of the fourth back surface electrode 144D are arranged at the same position as each other in the X-direction and adjacent to the second substrate side surface 24.

[0191] As shown in FIG. 10, the front surface side intermediate electrode 28C includes a first intermediate electrode 151, second intermediate electrodes 152A to 152D, third intermediate electrodes 153A to 153D, and fourth intermediate electrodes 154A to 154D.

[0192] In a plan view, the area of ​​the first intermediate electrode 151 is larger than the area of ​​each of the second intermediate electrodes 152A to 152D, the third intermediate electrodes 153A to 153D, and the fourth intermediate electrodes 154A to 154D. In a plan view, the area of ​​the first intermediate electrode 151 is larger than the combined area of ​​the second intermediate electrodes 152A to 152D, the third intermediate electrodes 153A to 153D, and the fourth intermediate electrodes 154A to 154D. In a plan view, the area of ​​the first intermediate electrode 151 is larger than half the area of ​​the surface of the intermediate substrate 27C. In a plan view, the area of ​​the first intermediate electrode 151 is larger than two-thirds the area of ​​the surface of the intermediate substrate 27C. In one example, the first intermediate electrode 151 is formed over substantially the entire surface of the intermediate substrate 27C in a plan view. The first intermediate electrode 151 has first openings 151AA to 151AD, second openings 151BA to 151BD, and third openings 151CA to 151CD.

[0193] In one example, the first openings 151AA and 151AB are in a line-symmetric relationship with respect to the imaginary center line VC. In one example, the second openings 151BA and 151BB are in a line-symmetric relationship with respect to the imaginary center line VC. In one example, the third openings 151CA and 151CB are in a line-symmetric relationship with respect to the imaginary center line VC.

[0194] The first openings 151AA and 151AB are oval in shape with the X direction as the longitudinal direction and the Y direction as the transverse direction. The second openings 151BA and 151BB are circular in shape. The third openings 151CA and 151CB are oval in shape with the X direction as the longitudinal direction and the Y direction as the transverse direction.

[0195] In one example, first openings 151AC and 151AD are in a line-symmetric relationship with respect to the imaginary center line VC. In one example, second openings 151BC and 151BD are in a line-symmetric relationship with respect to the imaginary center line VC. In one example, third openings 151CC and 151CD are in a line-symmetric relationship with respect to the imaginary center line VC.

[0196] The first openings 151AC and 151AD are oval in shape with their longitudinal direction in the Y direction and their transverse direction in the X direction. The second openings 151BC and 151BD are circular. The third openings 151CC and 151CD are oval in shape with their longitudinal direction in the Y direction and their transverse direction in the X direction.

[0197] Second intermediate electrode 152A is disposed within first opening 151AA, second intermediate electrode 152B is disposed within first opening 151AB, second intermediate electrode 152C is disposed within first opening 151AC, and second intermediate electrode 152D is disposed within first opening 151AD. Second intermediate electrodes 152A to 152D are formed in an oval shape that is one size smaller than first openings 152AA to 152AD in a plan view.

[0198] A third intermediate electrode 153A is disposed in the second opening 151BA, a third intermediate electrode 153B is disposed in the second opening 151BB, a third intermediate electrode 153C is disposed in the second opening 151BC, and a third intermediate electrode 153D is disposed in the second opening 151BD. The third intermediate electrodes 153A to 153D are formed in a circular shape that is one size smaller than the second openings 151BA to 151BD in a plan view.

[0199] Fourth intermediate electrode 154A is disposed in third opening 151CA, fourth intermediate electrode 154B is disposed in third opening 151CB, fourth intermediate electrode 154C is disposed in third opening 151CC, and fourth intermediate electrode 154D is disposed in third opening 151CD. Fourth intermediate electrodes 154A to 154D are formed in an oval shape that is one size smaller than third openings 151CA to 151CD in a plan view.

[0200] 8 to 10 , the substrate 20 includes first vias 161A to 161D, second vias 162A to 162D, third vias 163A to 163D, and fourth vias 164A to 164D. The first vias 161A to 161D, second vias 162A to 162D, third vias 163A to 163D, and fourth vias 164A to 164D are provided to penetrate each of the base materials 27A, 27B, and 27C, the front-side intermediate electrode 28C, and the back-side intermediate electrode 28D in the Z direction. The first vias 161A to 161D, the second vias 162A to 162D, the third vias 163A to 163D, and the fourth vias 164A to 164D are formed from a material including one or more appropriately selected from the group consisting of Ti, TiN, Au, Ag, Cu, Al, and W.

[0201] The first via 161A is electrically connected to the first surface electrode 131A, the first intermediate electrode 151 of the surface-side intermediate electrode 28C, the first intermediate electrode 151 of the back-side intermediate electrode 28D, and the first back-side electrode 141. As a result, the first surface electrode 131A, the first intermediate electrode 151 of the surface-side intermediate electrode 28C, the first intermediate electrode 151 of the back-side intermediate electrode 28D, and the first back-side electrode 141 are electrically connected to one another.

[0202] As shown in FIG. 8 , a plurality of first vias 161A are provided. The plurality of first vias 161A are provided on the first surface electrode 131A closer to the third substrate side surface 25. Therefore, in a plan view, the plurality of first vias 161A are arranged at positions on the first surface electrode 131A that overlap with the semiconductor light emitting element 30. The plurality of first vias 161A are arranged spaced apart from each other in the X direction and the Y direction. The number of first vias 161A arranged in the X direction is greater than the number of first vias 161A arranged in the Y direction. In a plan view, the region in which the plurality of first vias 161A are formed is larger than the area of ​​the semiconductor light emitting element 30. Therefore, some of the plurality of first vias 161A are arranged outward from the semiconductor light emitting element 30 in a plan view.

[0203] 8 to 10 , the first vias 161B to 161D are electrically connected to the first surface electrode 131B, the first intermediate electrode 151 of the surface-side intermediate electrode 28C, the first intermediate electrode 151 of the back-side intermediate electrode 28D, and the first back-side electrode 141. As a result, the first surface electrode 131B, the first intermediate electrode 151 of the surface-side intermediate electrode 28C, the first intermediate electrode 151 of the back-side intermediate electrode 28D, and the first back-side electrode 141 are electrically connected to one another. The first surface electrode 131A and the first surface electrode 131B are electrically connected by such electrode connections through the first vias 161A to 161D.

[0204] A plurality of first vias 161B to 161D are provided. The number of each of first vias 161B to 161D is smaller than the number of first vias 161A. The plurality of first vias 161B connect an end of first wiring portion 131BA of first surface electrode 131B that is closer to third substrate side surface 25 and first substrate side surface 23 to an end of first wide portion 141A of first back surface electrode 141 that is closer to third substrate side surface 25 and first substrate side surface 23. The plurality of first vias 161C connect an end of second wiring portion 131BB of first surface electrode 131B that is closer to third substrate side surface 25 and second substrate side surface 24 to an end of first wide portion 141A of first back surface electrode 141 that is closer to third substrate side surface 25 and second substrate side surface 24. The plurality of first vias 161D connect the center in the X direction of the third wiring portion 131BC of the first front surface electrode 131B and the narrow width portion 141C of the first rear surface electrode 141.

[0205] 8 to 10 , a plurality of second vias 162A to 162D are provided. The number of each of the second vias 162A to 162D is smaller than the number of each of the first vias 161A to 161D. The second via 162A is electrically connected to the second surface electrode 132A, the second intermediate electrode 152A of the surface-side intermediate electrode 28C, the second intermediate electrode 152A of the back-side intermediate electrode 28D, and the second back-side electrode 142A. As a result, the second surface electrode 132A, the second intermediate electrode 152A of the surface-side intermediate electrode 28C, the second intermediate electrode 152A of the back-side intermediate electrode 28D, and the second back-side electrode 142A are electrically connected to one another. The second via 162B is electrically connected to the second surface electrode 132B, the second intermediate electrode 152B of the surface-side intermediate electrode 28C, the second intermediate electrode 152B of the back-side intermediate electrode 28D, and the second back-side electrode 142B. As a result, the second surface electrode 132B, the second intermediate electrode 152B of the surface-side intermediate electrode 28C, the second intermediate electrode 152B of the back-side intermediate electrode 28D, and the second back-side electrode 142B are electrically connected to one another. The second via 162C is electrically connected to the second surface electrode 132C, the second intermediate electrode 152C of the surface-side intermediate electrode 28C, the second intermediate electrode 152C of the back-side intermediate electrode 28D, and the second back-side electrode 142C. As a result, the second surface electrode 132C, the second intermediate electrode 152C of the surface-side intermediate electrode 28C, the second intermediate electrode 152C of the back-side intermediate electrode 28D, and the second back-side electrode 142C are electrically connected to one another. The second via 162D is electrically connected to the second surface electrode 132D, the second intermediate electrode 152D of the surface-side intermediate electrode 28C, the second intermediate electrode 152D of the back-side intermediate electrode 28D, and the second back-side electrode 142D. As a result, the second surface electrode 132D, the second intermediate electrode 152D of the surface-side intermediate electrode 28C, the second intermediate electrode 152D of the back-side intermediate electrode 28D, and the second back-side electrode 142D are electrically connected to one another.

[0206] As shown in Figures 8 to 10, one third via 163A is provided for each of the third vias 163A to 163D. The third via 163A is electrically connected to the third surface electrode 133A, the third intermediate electrode 153A of the surface-side intermediate electrode 28C, the third intermediate electrode 153A of the back-side intermediate electrode 28D, and the third back-side electrode 143A. As a result, the third surface electrode 133A, the third intermediate electrode 153A of the surface-side intermediate electrode 28C, the third intermediate electrode 153A of the back-side intermediate electrode 28D, and the third back-side electrode 143A are electrically connected to one another. The third via 163B is electrically connected to the third surface electrode 133B, the third intermediate electrode 153B of the surface-side intermediate electrode 28C, the third intermediate electrode 153B of the back-side intermediate electrode 28D, and the third back-side electrode 143B. As a result, the third surface electrode 133B, the third intermediate electrode 153B of the front-side intermediate electrode 28C, the third intermediate electrode 153B of the rear-side intermediate electrode 28D, and the third rear-side electrode 143B are electrically connected to one another. The third via 163C is electrically connected to the third surface electrode 133C, the third intermediate electrode 153C of the front-side intermediate electrode 28C, the third intermediate electrode 153C of the rear-side intermediate electrode 28D, and the third rear-side electrode 143C. As a result, the third surface electrode 133C, the third intermediate electrode 153C of the front-side intermediate electrode 28C, the third intermediate electrode 153C of the rear-side intermediate electrode 28D, and the third rear-side electrode 143C are electrically connected to one another. The third via 163D is electrically connected to the third surface electrode 133D, the third intermediate electrode 153D of the front-side intermediate electrode 28C, the third intermediate electrode 153D of the rear-side intermediate electrode 28D, and the third rear-side electrode 143D. As a result, the third front surface electrode 133D, the third intermediate electrode 153D of the front surface side intermediate electrode 28C, the third intermediate electrode 153D of the rear surface side intermediate electrode 28D, and the third rear surface electrode 143D are electrically connected to one another.

[0207] 8 to 10 , a plurality of fourth vias 164A to 164D are provided. In one example, the number of fourth vias 164A to 164D is the same as the number of second vias 162A to 162D. The fourth via 164A is electrically connected to the fourth surface electrode 134A, the fourth intermediate electrode 154A of the surface-side intermediate electrode 28C, the fourth intermediate electrode 154A of the back-side intermediate electrode 28D, and the fourth back-side electrode 144A. As a result, the fourth surface electrode 134A, the fourth intermediate electrode 154A of the surface-side intermediate electrode 28C, the fourth intermediate electrode 154A of the back-side intermediate electrode 28D, and the fourth back-side electrode 144A are electrically connected to one another. The fourth via 164B is electrically connected to the fourth surface electrode 134B, the fourth intermediate electrode 154B of the surface-side intermediate electrode 28C, the fourth intermediate electrode 154B of the back-side intermediate electrode 28D, and the fourth back-side electrode 144B. As a result, the fourth surface electrode 134B, the fourth intermediate electrode 154B of the surface-side intermediate electrode 28C, the fourth intermediate electrode 154B of the back-side intermediate electrode 28D, and the fourth back-side electrode 144B are electrically connected to one another. The fourth via 164C is electrically connected to the fourth surface electrode 134C, the fourth intermediate electrode 154C of the surface-side intermediate electrode 28C, the fourth intermediate electrode 154C of the back-side intermediate electrode 28D, and the fourth back-side electrode 144C. As a result, the fourth surface electrode 134C, the fourth intermediate electrode 154C of the surface-side intermediate electrode 28C, the fourth intermediate electrode 154C of the back-side intermediate electrode 28D, and the fourth back-side electrode 144C are electrically connected to one another. The fourth via 164D is electrically connected to the fourth surface electrode 134D, the fourth intermediate electrode 154D of the surface-side intermediate electrode 28C, the fourth intermediate electrode 154D of the back-side intermediate electrode 28D, and the fourth back-side electrode 144D. As a result, the fourth surface electrode 134D, the fourth intermediate electrode 154D of the surface-side intermediate electrode 28C, the fourth intermediate electrode 154D of the back-side intermediate electrode 28D, and the fourth back-side electrode 144D are electrically connected to one another.

[0208] 8, a semiconductor light emitting element 30, a first drive circuit 40, a second drive circuit 50, a third drive circuit 110, and a fourth drive circuit 120 are mounted on a plurality of surface electrodes 28A. Detailed configurations and embodiments of the semiconductor light emitting element 30 and the first to fourth drive circuits 40, 50, 110, and 120 will be described below. Note that components common to the first embodiment are designated by the same reference numerals, and their description may be omitted.

[0209] The semiconductor light emitting element 30 is mounted on the first surface electrode 131A. That is, the element back surface electrode 35 (not shown in FIG. 8, see FIG. 3) of the semiconductor light emitting element 30 is joined to the first surface electrode 131A by a conductive bonding material SD (not shown in FIG. 8, see FIG. 3). This electrically connects the element back surface electrode 35 to the first surface electrode 131A. The semiconductor light emitting element 30 is disposed biased toward the third substrate side surface 25 with respect to the center of the first surface electrode 131A in the Y direction.

[0210] The size, shape, and configuration of the semiconductor light emitting device 30 of the second embodiment are similar to those of the semiconductor light emitting device 30 of the first embodiment. On the other hand, as described above, the semiconductor light emitting device 30 of the second embodiment divides the eight light emitting portions 33 into first to fourth light emitting portions 33A to 33D, each of which is made up of two light emitting portions 33.

[0211] The first light-emitting portion 33A is composed of two of the eight light-emitting portions 33 that are closest to the imaginary center line VC and are arranged closer to the first substrate side surface 23 than the imaginary center line VC. The second light-emitting portion 33B is composed of two of the eight light-emitting portions 33 that are closest to the imaginary center line VC and are arranged closer to the second substrate side surface 24 than the imaginary center line VC. The third light-emitting portion 33C is composed of two of the eight light-emitting portions 33 that are located at the end closer to the first substrate side surface 23 in the X direction. The fourth light-emitting portion 33D is composed of two of the eight light-emitting portions 33 that are located at the end closer to the second substrate side surface 24 in the X direction.

[0212] In the first drive circuit 40, a vertical transistor is used as the first switching element 41 in the second embodiment, as in the first embodiment. However, the shape of the source electrode 41S and the position of the gate electrode 41G of the first switching element 41 in the second embodiment are different from those in the first embodiment. More specifically, the gate electrode 41G is disposed at one of the four corners of the second element surface 41A that is closest to the first substrate side surface 23 and the fourth substrate side surface 26. The source electrode 41S is formed over most of the second element surface 41A and includes a recessed portion that avoids the gate electrode 41G.

[0213] The first switching element 41 is mounted on the second surface electrode 132A. That is, the drain electrode 41D (not shown in FIG. 8, see FIG. 3) of the first switching element 41 is joined to the second surface electrode 132A by a conductive bonding material SD (not shown in FIG. 8, see FIG. 3). This electrically connects the drain electrode 41D to the second surface electrode 132A. The first switching element 41 is disposed in a narrow portion of the second surface electrode 132A.

[0214] The source electrode 41S of the first switching element 41 is electrically connected to a plurality of first element surface electrodes 34A corresponding to the first light-emitting portion 33A of the semiconductor light-emitting element 30 by a plurality of wires W1. The source electrode 41S of the first switching element 41 is electrically connected to the fourth surface electrode 134A by a wire W2. The gate electrode 41G of the first switching element 41 is electrically connected to the third surface electrode 133A by a wire W3.

[0215] In a plan view, the semiconductor light emitting element 30 and the first capacitor 42 are arranged spaced apart from each other in the Y direction. The first capacitor 42 is arranged on the opposite side of the first switching element 41 from the semiconductor light emitting element 30 in the Y direction. In other words, in a plan view, the first switching element 41 is arranged between the semiconductor light emitting element 30 and the first capacitor 42 in the Y direction.

[0216] A plurality of first capacitors 42 (four in the second embodiment) are provided. The plurality of first capacitors 42 are connected in parallel to each other. The plurality of first capacitors 42 are arranged spaced apart from each other in the X direction. Each first capacitor 42 is arranged to straddle the second surface electrode 132A and the third wiring portion 131BC of the first surface electrode 131B in the Y direction. Each first capacitor 42 is mounted on the second surface electrode 132A and the third wiring portion 131BC. More specifically, each first capacitor 42 is individually bonded to the second surface electrode 132A and the third wiring portion 131BC by a conductive bonding material SD (not shown in FIG. 8 , see FIG. 3 ). In the example of FIG. 8 , the first electrode 42A is bonded to the second surface electrode 132A by the conductive bonding material SD. This electrically connects the first electrode 42A to the second surface electrode 132A. The second electrode 42B is joined to the third wiring portion 131BC by a conductive bonding material SD, so that the second electrode 42B is electrically connected to the third wiring portion 131BC (first surface electrode 131B).

[0217] The first electrode 42A of each first capacitor 42 is disposed on the wide portion of the second surface electrode 132A. The first capacitors 42 arranged in the X direction are disposed across the entire wide portion in the X direction. In other words, the dimension of the wide portion in the X direction is set so that the first capacitors 42 arranged in the X direction can be disposed.

[0218] The second electrode 42B of each first capacitor 42 is disposed at one of the Y-direction ends of the third wiring portion 131BC that is closer to the second surface electrode 132A. That is, the second electrode 42B of each first capacitor 42 is disposed closer to the second surface electrode 132A than the plurality of first vias 161D in the Y-direction. Some of the plurality of first capacitors 42 are disposed closer to the first substrate side surface 23 than the first switching elements 41 when viewed from the Y-direction.

[0219] In the second drive circuit 50, the second switching element 51 of the second embodiment uses a vertical transistor, as in the first embodiment. However, the shape of the source electrode 51S and the position of the gate electrode 51G of the second switching element 51 of the second embodiment differ from those of the first embodiment. More specifically, the gate electrode 51G is disposed at one of the four corners of the second element surface 51A that is closest to the second substrate side surface 24 and the fourth substrate side surface 26. The source electrode 51S is formed over most of the second element surface 51A and includes a recessed portion that avoids the gate electrode 51G. Thus, in the second embodiment, the configuration of the second switching element 51 differs from the configuration of the first switching element 41.

[0220] The second switching element 51 is mounted on the second surface electrode 132B. That is, the drain electrode 51D (not shown in FIG. 8, see FIG. 11) of the second switching element 51 is joined to the second surface electrode 132B by a conductive bonding material SD. As a result, the drain electrode 51D is electrically connected to the second surface electrode 132B.

[0221] The second switching element 51 is disposed in a narrow portion of the second surface electrode 132B. In a plan view, the distance D1 between the semiconductor light emitting element 30 and the first switching element 41 in the Y direction is equal to the distance D2 between the semiconductor light emitting element 30 and the second switching element 51 in the Y direction. Here, if the difference between the distance D1 and the distance D2 is, for example, within 10% of the distance D1, it can be said that the distance D1 is equal to the distance D2.

[0222] The source electrode 51S of the second switching element 51 is electrically connected to the plurality of second element surface electrodes 34B corresponding to the second light-emitting portion 33B of the semiconductor light-emitting element 30 by a plurality of wires W1. The source electrode 51S of the second switching element 51 is electrically connected to the fourth surface electrode 134B by a wire W2. The gate electrode 51G of the second switching element 51 is electrically connected to the third surface electrode 133B by a wire W3.

[0223] In one example, the lengths of the two wires W1 connecting the first element surface electrode 34A and the source electrode 41S of the first switching element 41 are equal to each other in a planar view. In another example, the lengths of the two wires W1 connecting the second element surface electrode 34B and the source electrode 51S of the second switching element 51 are equal to each other in a planar view.

[0224] Since the distance D1 and the distance D2 are equal, the length of each wire W1 can be adjusted so that the total length of the two wires W1 connecting the first element surface electrode 34A and the source electrode 41S of the first switching element 41 is equal to the total length of the two wires W1 connecting the second element surface electrode 34B and the source electrode 51S of the second switching element 51 when viewed in a plane. Here, if the difference between the total length of the two wires W1 connecting the first element surface electrode 34A and the source electrode 41S of the first switching element 41 in a planar view and the total length of the two wires W1 connecting the second element surface electrode 34B and the source electrode 51S of the second switching element 51 in a planar view is, for example, within 10% of the total length of the two wires W1 connecting the first element surface electrode 34A and the source electrode 41S of the first switching element 41 in a planar view, it can be said that the total length of the two wires W1 connecting the first element surface electrode 34A and the source electrode 41S of the first switching element 41 in a planar view is equal to the total length of the two wires W1 connecting the second element surface electrode 34B and the source electrode 51S of the second switching element 51.

[0225] In a plan view, the semiconductor light emitting element 30 and the second capacitor 52 are arranged spaced apart from each other in the Y direction. The second capacitor 52 is arranged on the opposite side of the second switching element 51 from the semiconductor light emitting element 30 in the Y direction. In other words, in a plan view, the second switching element 51 is arranged between the semiconductor light emitting element 30 and the second capacitor 52 in the Y direction.

[0226] A plurality of second capacitors 52 (four in the second embodiment) are provided. The plurality of second capacitors 52 are connected in parallel to each other. The plurality of second capacitors 52 are arranged spaced apart from each other in the X direction. Each second capacitor 52 is disposed so as to straddle the second surface electrode 132B and the third wiring portion 131BC of the first surface electrode 131B in the Y direction. Each second capacitor 52 is mounted on the second surface electrode 132B and the third wiring portion 131BC. More specifically, each second capacitor 52 is individually bonded to the second surface electrode 132B and the third wiring portion 131BC by a conductive bonding material SD (not shown). In the example of FIG. 8 , the first electrode 52A is bonded to the second surface electrode 132B by the conductive bonding material SD. This electrically connects the first electrode 52A to the second surface electrode 132B. The second electrode 52B is joined to the third wiring portion 131BC by a conductive bonding material SD. This electrically connects the second electrode 52B to the third wiring portion 131BC (first surface electrode 131B). Therefore, it can be said that the second electrode 52B of the second capacitor 52 and the second electrode 42B of the first capacitor 42 are electrically connected.

[0227] The first electrode 52A of each second capacitor 52 is disposed on the wide portion of the second surface electrode 132B. The second capacitors 52 arranged in the X direction are disposed across the entire wide portion in the X direction. In other words, the dimension of the wide portion in the X direction is set so that the second capacitors 52 arranged in the X direction can be disposed.

[0228] The second electrode 52B of each second capacitor 52 is disposed at one of the Y-direction ends of the third wiring portion 131BC that is closer to the second surface electrode 132B. That is, the second electrode 52B of each second capacitor 52 is disposed closer to the second surface electrode 132B than the plurality of first vias 161D in the Y-direction. Some of the plurality of second capacitors 52 are disposed closer to the second substrate side surface 24 than the second switching elements 51 when viewed from the Y-direction.

[0229] In the third drive circuit 110, a vertical transistor is used as the third switching element 111. The third switching element 111 has the same configuration and size as the second switching element 51 of the second embodiment. The third switching element 111 includes a second element front surface 111A and a second element back surface (not shown) facing opposite each other in the Z direction. A source electrode 111S and a gate electrode 111G are formed on the second element front surface 111A. A drain electrode 111D (not shown in FIG. 8, see FIG. 11) is formed on the second element back surface. The source electrode 111S and the gate electrode 111G have the same shape, configuration, and arrangement as the source electrode 51S and the gate electrode 51G.

[0230] The third switching element 111 is mounted on the second surface electrode 132C. That is, the drain electrode 111D of the third switching element 111 is joined to the second surface electrode 132C by a conductive bonding material SD. As a result, the drain electrode 111D is electrically connected to the second surface electrode 132C.

[0231] The third switching element 111 is disposed in a narrow portion of the second surface electrode 132C. Therefore, the third switching element 111 is disposed closer to the first substrate side surface 23 in the X direction than the semiconductor light emitting element 30. The third switching element 111 is disposed at a position overlapping with the semiconductor light emitting element 30 when viewed from the X direction.

[0232] The source electrode 111S of the third switching element 111 is electrically connected to a plurality of third element surface electrodes 34C corresponding to the third light-emitting portion 33C of the semiconductor light-emitting element 30 by a plurality of wires W1. The source electrode 111S of the third switching element 111 is electrically connected to the fourth surface electrode 134C by a wire W2. The gate electrode 111G of the third switching element 111 is electrically connected to the third surface electrode 133C by a wire W3.

[0233] In a plan view, the semiconductor light emitting element 30 and the third capacitor 112 are arranged spaced apart from each other in the X direction. The third capacitor 112 is arranged on the opposite side of the third switching element 111 from the semiconductor light emitting element 30 in the X direction. In other words, in a plan view, the third switching element 111 is arranged between the semiconductor light emitting element 30 and the third capacitor 112 in the X direction.

[0234] A plurality of third capacitors 112 (four in the second embodiment) are provided. The third capacitors 112 are connected in parallel to each other. The third capacitors 112 are arranged spaced apart from each other in the Y direction. Each third capacitor 112 is arranged to straddle the second surface electrode 132C and the first wiring portion 131BA of the first surface electrode 131B in the X direction. Each third capacitor 112 is mounted on the second surface electrode 132C and the first wiring portion 131BA. Each third capacitor 112 is individually bonded to the second surface electrode 132C and the first wiring portion 131BA by a conductive bonding material SD (not shown). More specifically, each third capacitor 112 includes a first electrode 112A and a second electrode 112B. In the example of FIG. 8 , the first electrode 112A is bonded to the second surface electrode 132C by the conductive bonding material SD. As a result, the first electrode 112A is electrically connected to the second surface electrode 132C. The second electrode 112B is joined to the first wiring portion 131BA by the conductive bonding material SD. As a result, the second electrode 112B is electrically connected to the first wiring portion 131BA (first surface electrode 131B). Therefore, it can be said that the second electrode 112B of the third capacitor 112 and the second electrode 42B of the first capacitor 42 are electrically connected.

[0235] The first electrode 112A of each third capacitor 112 is disposed on the wide portion of the second surface electrode 132C. The third capacitors 112 arranged in the Y direction are disposed across the entire wide portion in the Y direction. In other words, the dimension of the wide portion in the Y direction is set so that the third capacitors 112 arranged in the Y direction can be disposed thereon.

[0236] The second electrode 112B of each third capacitor 112 is disposed at one of the ends of the first wiring portion 131BA in the X direction that is closer to the second surface electrode 132C. That is, the second electrode 112B of each third capacitor 112 is disposed closer to the second surface electrode 132C than the plurality of first vias 161B in the X direction. Some of the plurality of third capacitors 112 are disposed closer to the fourth substrate side surface 26 than the third switching elements 111 when viewed from the X direction.

[0237] In the fourth drive circuit 120, a vertical transistor is used as the fourth switching element 121. The fourth switching element 121 has the same configuration and size as the first switching element 41 of the second embodiment. The fourth switching element 121 includes a second element front surface 121A and a second element back surface (not shown) facing opposite each other in the Z direction. A source electrode 121S and a gate electrode 121G are formed on the second element front surface 121A. A drain electrode 121D (not shown in FIG. 8, see FIG. 11) is formed on the second element back surface. The shape, configuration, and arrangement of the source electrode 121S and the gate electrode 121G are the same as those of the source electrode 41S and the gate electrode 41G.

[0238] The fourth switching element 121 is mounted on the second surface electrode 132D. That is, the drain electrode 121D of the fourth switching element 121 is joined to the second surface electrode 132D by a conductive bonding material SD (not shown). This electrically connects the drain electrode 121D to the second surface electrode 132D.

[0239] The fourth switching element 121 is disposed in a narrow portion of the second surface electrode 132D. Therefore, the fourth switching element 121 is disposed closer to the second substrate side surface 24 than the semiconductor light emitting element 30 in the X direction. The fourth switching element 121 is disposed in a position overlapping the semiconductor light emitting element 30 when viewed from the X direction. In this manner, the third switching element 111 and the fourth switching element 121 can be said to be disposed dispersedly on both sides of the semiconductor light emitting element 30 in the X direction. In a plan view, the distance D3 between the semiconductor light emitting element 30 and the third switching element 111 in the X direction is equal to the distance D4 between the semiconductor light emitting element 30 and the fourth switching element 121 in the X direction. Here, if the difference between the distances D3 and D4 is, for example, within 10% of the distance D3, then the distance D3 can be said to be equal to the distance D4.

[0240] The source electrode 121S of the fourth switching element 121 is electrically connected to a plurality of fourth element surface electrodes 34D corresponding to the fourth light-emitting portion 33D of the semiconductor light-emitting element 30 by a plurality of wires W1. The source electrode 121S of the fourth switching element 121 is electrically connected to the fourth surface electrode 134D by a wire W2. The gate electrode 121G of the fourth switching element 121 is electrically connected to the third surface electrode 133D by a wire W3.

[0241] Since the distance D3 and the distance D4 are equal, the length of each wire W1 can be adjusted so that the total length of the two wires W1 connecting the third element surface electrode 34C and the source electrode 111S of the third switching element 111 is equal to the total length of the two wires W1 connecting the fourth element surface electrode 34D and the source electrode 121S of the fourth switching element 121 when viewed in a plane. Here, if the difference between the total length of the two wires W1 connecting the third element surface electrode 34C and the source electrode 111S of the third switching element 111 in a planar view and the total length of the two wires W1 connecting the fourth element surface electrode 34D and the source electrode 121S of the fourth switching element 121 in a planar view is, for example, within 10% of the total length of the two wires W1 connecting the third element surface electrode 34C and the source electrode 111S of the third switching element 111 in a planar view, it can be said that the total length of the two wires W1 connecting the third element surface electrode 34C and the source electrode 111S of the third switching element 111 in a planar view is equal to the total length of the two wires W1 connecting the fourth element surface electrode 34D and the source electrode 121S of the fourth switching element 121.

[0242] In a plan view, the semiconductor light emitting element 30 and the fourth capacitor 122 are arranged spaced apart from each other in the X direction. The fourth capacitor 122 is arranged on the opposite side of the semiconductor light emitting element 30 with respect to the fourth switching element 121 in the X direction. In other words, in a plan view, the fourth switching element 121 is arranged between the semiconductor light emitting element 30 and the fourth capacitor 122 in the X direction. In this way, it can be said that the third capacitor 112 and the fourth capacitor 122 are arranged dispersedly on both sides of the semiconductor light emitting element 30 in the X direction.

[0243] A plurality of fourth capacitors 122 (four in the second embodiment) are provided. The plurality of fourth capacitors 122 are connected in parallel to each other. The plurality of fourth capacitors 122 are arranged spaced apart from each other in the Y direction. Each fourth capacitor 122 is arranged to straddle the second surface electrode 132D and the second wiring portion 131BB of the first surface electrode 131B in the X direction. Each fourth capacitor 122 is mounted on the second surface electrode 132D and the second wiring portion 131BB. Each fourth capacitor 122 is individually bonded to the second surface electrode 132D and the second wiring portion 131BB by a conductive bonding material SD (not shown). More specifically, each fourth capacitor 122 includes a first electrode 122A and a second electrode 122B. In the example of FIG. 8 , each first electrode 122A is bonded to the second surface electrode 132D by the conductive bonding material SD. As a result, the first electrode 122A is electrically connected to the second surface electrode 132D. Each second electrode 122B is joined to the second wiring portion 131BB by the conductive bonding material SD. As a result, the second electrode 122B is electrically connected to the second wiring portion 131BB (first surface electrode 131B). Therefore, it can be said that the second electrode 122B of the fourth capacitor 122 and the second electrode 42B of the first capacitor 42 are electrically connected. In other words, it can be said that the second electrodes 42B, 52B, 112B, and 122B of the first to fourth capacitors 42, 52, 112, and 122 are electrically connected to each other via the first surface electrode 131B.

[0244] The first electrode 122A of each fourth capacitor 122 is disposed on the wide portion of the second surface electrode 132D. The plurality of fourth capacitors 122 arranged in the Y direction are disposed across the entire wide portion in the Y direction. In other words, the dimension of the wide portion in the Y direction is set so that the plurality of fourth capacitors 122 arranged in the Y direction can be disposed thereon.

[0245] The second electrode 122B of each fourth capacitor 122 is disposed at one of the two ends of the second wiring portion 131BB in the X direction that is closer to the second surface electrode 132D. That is, the second electrode 122B of each fourth capacitor 122 is disposed closer to the second surface electrode 132D than the plurality of first vias 161C in the X direction. Some of the plurality of fourth capacitors 122 are disposed closer to the fourth substrate side surface 26 than the fourth switching elements 121 when viewed from the X direction.

[0246] The semiconductor light-emitting device 10 further includes first to fourth protection diodes 101 to 104. The first protection diode 101 is a diode that protects the first light-emitting portion 33A of the semiconductor light-emitting element 30. The first protection diode 101 is disposed closer to the first substrate side surface 23 in the X direction than the semiconductor light-emitting element 30, the first switching element 41, and the plurality of first capacitors 42. In one example, the first protection diode 101 is disposed at a position overlapping the third switching element 111 when viewed from the Y direction. The first protection diode 101 is disposed on the opposite side of the semiconductor light-emitting element 30 in the Y direction with respect to the first switching element 41. The first protection diode 101 is disposed at the same position as the first capacitor 42 in the Y direction. The first protection diode 101 is disposed so as to straddle the fourth surface electrode 134A and the third wiring portion 131BC of the first surface electrode 131B in the Y direction. The first protection diode 101 is arranged such that the first anode electrode 101A and the first cathode electrode 101B are at the same position in the X direction and spaced apart from each other in the Y direction. The first protection diode 101 is mounted on the fourth surface electrode 134A and the first surface electrode 131B. More specifically, the first protection diode 101 is individually bonded to the fourth surface electrode 134A and the first surface electrode 131B by a conductive bonding material SD.

[0247] The first protection diode 101 is connected in anti-parallel to the first light-emitting portion 33A. More specifically, the first anode electrode 101A is bonded to the first surface electrode 131B by a conductive bonding material SD. The first anode electrode 101A is disposed on the third wiring portion 131BC of the first surface electrode 131B. This electrically connects the first anode electrode 101A to the back surface electrode 35 of the semiconductor light-emitting element 30 via the first surface electrode 131B. The first cathode electrode 101B is bonded to the fourth surface electrode 134A by a conductive bonding material SD. The first cathode electrode 101B is disposed on the second opposing portion of the fourth surface electrode 134A. This electrically connects the first cathode electrode 101B to the plurality of first element surface electrodes 34A corresponding to the first light-emitting portion 33A of the semiconductor light-emitting element 30 via the wire W2, the source electrode 41S of the first switching element 41, and the wire W1.

[0248] The second protection diode 102 is a diode that protects the second light-emitting portion 33B of the semiconductor light-emitting element 30. The second protection diode 102 is disposed closer to the second substrate side surface 24 in the X direction than the semiconductor light-emitting element 30, the second switching element 51, and the plurality of second capacitors 52. In one example, the second protection diode 102 is disposed in a position overlapping the fourth switching element 121 when viewed from the Y direction. The second protection diode 102 is disposed on the opposite side of the semiconductor light-emitting element 30 in the Y direction with respect to the second switching element 51. The second protection diode 102 is disposed in the same position as the second capacitor 52 in the Y direction. The second protection diode 102 is disposed so as to straddle the Y direction between the fourth surface electrode 134B and the third wiring portion 131BC of the first surface electrode 131B. The second protection diode 102 is mounted on the fourth surface electrode 134B and the first surface electrode 131B. The mounting manner of the second protection diode 102 is the same as that of the first protection diode 101.

[0249] The second protection diode 102 is connected in anti-parallel to the second light-emitting portion 33B. More specifically, the second anode electrode 102A is bonded to the third wiring portion 131BC of the first surface electrode 131B by a conductive bonding material SD. This electrically connects the second anode electrode 102A to the element back surface electrode 35 of the semiconductor light-emitting element 30 via the first surface electrode 131B. The second cathode electrode 102B is bonded to a second opposing portion of the fourth surface electrode 134B by a conductive bonding material SD. This electrically connects the second cathode electrode 102B to a plurality of second element surface electrodes 34B corresponding to the second light-emitting portion 33B of the semiconductor light-emitting element 30 via the wire W2, the source electrode 51S of the second switching element 51, and the wire W1.

[0250] The third protection diode 103 is a diode that protects the third light-emitting portion 33C of the semiconductor light-emitting element 30. The third protection diode 103 is arranged closer to the fourth substrate side surface 26 in the Y direction than the semiconductor light-emitting element 30, the third switching element 111, and the plurality of third capacitors 112. In one example, the third protection diode 103 is arranged at a position overlapping with the first switching element 41 when viewed from the X direction. The third protection diode 103 is arranged on the opposite side of the semiconductor light-emitting element 30 with respect to the third switching element 111 in the X direction. The third protection diode 103 is arranged at the same position as the third capacitor 112 in the X direction. The third protection diode 103 is arranged to straddle the Y direction between the fourth surface electrode 134C and the first wiring portion 131BA of the first surface electrode 131B.

[0251] The third protection diode 103 includes a third anode electrode 103A and a third cathode electrode 103B. The third protection diode 103 is arranged such that the third anode electrode 103A and the third cathode electrode 103B are at the same position in the Y direction and spaced apart from each other in the X direction. The third protection diode 103 is mounted on the fourth surface electrode 134C and the first surface electrode 131B. More specifically, the third protection diode 103 is individually bonded to the fourth surface electrode 134C and the first surface electrode 131B by a conductive bonding material SD.

[0252] The third protection diode 103 is connected in anti-parallel to the third light-emitting portion 33C. More specifically, the third anode electrode 103A is bonded to the first surface electrode 131B by a conductive bonding material SD. The third anode electrode 103A is disposed on the first wiring portion 131BA of the first surface electrode 131B. This electrically connects the third anode electrode 103A to the back surface electrode 35 of the semiconductor light-emitting element 30 via the first surface electrode 131B. The third cathode electrode 103B is bonded to the fourth surface electrode 134C by a conductive bonding material SD. The third cathode electrode 103B is disposed on the second opposing portion of the fourth surface electrode 134C. This electrically connects the third cathode electrode 103B to a plurality of third element surface electrodes 34C corresponding to the third light-emitting portion 33C of the semiconductor light-emitting element 30 via the wire W2, the source electrode 111S of the third switching element 111, and the wire W1.

[0253] The fourth protection diode 104 is a diode that protects the fourth light-emitting portion 33D of the semiconductor light-emitting element 30. The fourth protection diode 104 is arranged closer to the fourth substrate side surface 26 in the Y direction than the semiconductor light-emitting element 30, the fourth switching element 121, and the plurality of fourth capacitors 122. In one example, the fourth protection diode 104 is arranged at a position overlapping with the second switching element 51 when viewed from the X direction. The fourth protection diode 104 is arranged on the opposite side of the semiconductor light-emitting element 30 with respect to the fourth switching element 121 in the X direction. The fourth protection diode 104 is arranged at the same position as the fourth capacitor 122 in the X direction. The fourth protection diode 104 is arranged to straddle the fourth surface electrode 134D and the second wiring portion 131BB of the first surface electrode 131B in the Y direction.

[0254] The fourth protection diode 104 includes a fourth anode electrode 104A and a fourth cathode electrode 104B. The fourth protection diode 104 is arranged such that the fourth anode electrode 104A and the fourth cathode electrode 104B are at the same position in the Y direction and spaced apart from each other in the X direction. The fourth protection diode 104 is mounted on the fourth surface electrode 134D and the first surface electrode 131B. More specifically, the fourth protection diode 104 is individually bonded to the fourth surface electrode 134D and the first surface electrode 131B by a conductive bonding material SD.

[0255] The fourth protection diode 104 is connected in anti-parallel to the fourth light-emitting portion 33D. More specifically, the fourth anode electrode 104A is bonded to the first surface electrode 131B by a conductive bonding material SD. The fourth anode electrode 104A is disposed on the second wiring portion 131BB of the first surface electrode 131B. This electrically connects the fourth anode electrode 104A to the back surface electrode 35 of the semiconductor light-emitting element 30 via the first surface electrode 131B. The fourth cathode electrode 104B is bonded to the fourth surface electrode 134D by a conductive bonding material SD. The fourth cathode electrode 104B is disposed on the second opposing portion of the fourth surface electrode 134D. This electrically connects the fourth cathode electrode 104B to a plurality of fourth element surface electrodes 34D corresponding to the fourth light-emitting portion 33D of the semiconductor light-emitting element 30 via the wire W2, the source electrode 121S of the fourth switching element 121, and the wire W1. In this manner, the first to fourth anode electrodes 101A to 104A of the first to fourth protection diodes 101 to 104 are electrically connected to one another via the first surface electrode 131B.

[0256] 11 , similar to the first embodiment, the light-emitting system 800 includes a DC power supply 801, a capacitor 802, a current-limiting resistor 803, a gate driver IC 805, a pulse generator 806, and a control power supply 807. Unlike the first embodiment, the light-emitting system 800 also includes four backflow prevention diodes 804A to 804D. Below, differences from the first embodiment will be described in detail, and a description of the configuration common to the first embodiment will be omitted.

[0257] The anodes of the reverse current blocking diodes 804A to 804D are electrically connected to the current limiting resistor 803. The cathode of the reverse current blocking diode 804A is electrically connected to the second back surface electrode 142A, the cathode of the reverse current blocking diode 804B is electrically connected to the second back surface electrode 142B, the cathode of the reverse current blocking diode 804C is electrically connected to the second back surface electrode 142C, and the cathode of the reverse current blocking diode 804D is electrically connected to the second back surface electrode 142D.

[0258] The drain electrode 41D of the first switching element 41 and the first electrode 42A of the first capacitor 42 are electrically connected to the cathode of the reverse current blocking diode 804A via the second back surface electrode 142A. The drain electrode 51D of the second switching element 51 and the first electrode 52A of the second capacitor 52 are electrically connected to the cathode of the reverse current blocking diode 804B via the second back surface electrode 142B. The drain electrode 111D of the third switching element 111 and the first electrode 112A of the third capacitor 112 are electrically connected to the cathode of the reverse current blocking diode 804C via the second back surface electrode 142C. The drain electrode 121D of the fourth switching element 121 and the first electrode 122A of the fourth capacitor 122 are electrically connected to the cathode of the reverse current blocking diode 804D via the second back surface electrode 142D.

[0259] The source electrode 41S of the first switching element 41 is electrically connected to a first element surface electrode 34A (see FIG. 8 ) which serves as a first anode electrode of the first light-emitting portion 33A and a first cathode electrode 101B of the first protection diode 101. The source electrode 51S of the second switching element 51 is electrically connected to a second element surface electrode 34B (see FIG. 8 ) which serves as a second anode electrode of the second light-emitting portion 33B and a second cathode electrode 102B of the second protection diode 102. The source electrode 111S of the third switching element 111 is electrically connected to a third element surface electrode 34C which serves as a third anode electrode of the third light-emitting portion 33C and a third cathode electrode 103B of the third protection diode 103. The source electrode 121S of the fourth switching element 121 is electrically connected to a fourth element surface electrode 34D serving as a fourth anode electrode of the fourth light emitting portion 33D and a fourth cathode electrode 104B of the fourth protection diode 104.

[0260] The back surface electrode 35 of the element, which serves as a common cathode electrode for the first to fourth light-emitting units 33A to 33D, the first to fourth anode electrodes 101A to 104A of the first to fourth protection diodes 101 to 104, and the second electrodes 42B, 52B, 112B, and 122B of the first to fourth capacitors 42, 52, 112, and 122, are electrically connected to the first back surface electrode 141. Because the first back surface electrode 141 is connected to ground, it can be said that the back surface electrode 35 of the element, which serves as a cathode for the first to fourth light-emitting units 33A to 33D, the first to fourth anode electrodes 101A to 104A of the first to fourth protection diodes 101 to 104, and the second electrodes 42B, 52B, 112B, and 122B of the first to fourth capacitors 42, 52, 112, and 122 are connected to ground.

[0261] The gate driver IC 805 is electrically connected to the gate electrodes 41G, 51G, 111G, and 121G of the first to fourth switching elements 41, 51, 111, and 121, respectively. That is, the gate driver IC 805 is configured to individually control the first to fourth switching elements 41, 51, 111, and 121. The driving of the first to fourth light-emitting units 33A to 33D in the semiconductor light-emitting device 10 of the second embodiment is similar to that in the first embodiment.

[0262] [Effects] According to the semiconductor light emitting device 10 of the second embodiment, in addition to the effects according to the first embodiment, the following effects can be obtained.

[0263] (2-1) The third drive circuit 110 includes a third switching element 111 that controls the drive of the third light-emitting unit 33C and a third capacitor 112 that supplies current to the third light-emitting unit 33C. The fourth drive circuit 120 includes a fourth switching element 121 that controls the drive of the fourth light-emitting unit 33D and a fourth capacitor 122 that supplies current to the fourth light-emitting unit 33D.

[0264] According to this configuration, a loop-shaped third current path formed by the third light-emitting portion 33C of the semiconductor light-emitting element 30, the third switching element 111, and the third capacitor 112 can be formed within the semiconductor light-emitting device 10. This shortens the length of the third current path, thereby reducing inductance due to the length of the third current path. Furthermore, a loop-shaped fourth current path formed by the fourth light-emitting portion 33D of the semiconductor light-emitting element 30, the fourth switching element 121, and the fourth capacitor 122 can be formed within the semiconductor light-emitting device 10. This shortens the length of the fourth current path, thereby reducing inductance due to the length of the fourth current path. Additionally, because both the third and fourth current paths are short, variation in the lengths of the third and fourth current paths can be reduced. This reduces variation in inductance of the third and fourth current paths.

[0265] (2-2) In a plan view, the semiconductor light-emitting element 30 and the third capacitor 112 are spaced apart from each other in the X direction. In a plan view, the third switching element 111 is located between the semiconductor light-emitting element 30 and the third capacitor 112 in the X direction. In a plan view, the semiconductor light-emitting element 30 and the fourth capacitor 122 are spaced apart from each other in the X direction. In a plan view, the fourth switching element 121 is located between the semiconductor light-emitting element 30 and the fourth capacitor 122 in the Y direction.

[0266] According to this configuration, the loop-shaped third current path formed by the third light-emitting unit 33C of the semiconductor light-emitting element 30, the third switching element 111, and the third capacitor 112 can be shortened compared to a configuration in which the third switching element 111 is arranged on the opposite side of the semiconductor light-emitting element 30 with respect to the third capacitor 112 in the X direction. Also, the loop-shaped fourth current path formed by the fourth light-emitting unit 33D of the semiconductor light-emitting element 30, the fourth switching element 121, and the fourth capacitor 122 can be shortened compared to a configuration in which the fourth switching element 121 is arranged on the opposite side of the semiconductor light-emitting element 30 with respect to the fourth capacitor 122 in the X direction.

[0267] (2-3) The distance D3 between the semiconductor light emitting element 30 and the third switching element 111 in the X direction is equal to the distance D4 between the semiconductor light emitting element 30 and the fourth switching element 121 in the X direction.

[0268] According to this configuration, the current path between the semiconductor light emitting element 30 and the third switching element 111 is equal to the current path between the semiconductor light emitting element 30 and the fourth switching element 121. This reduces the variation in length between the third current path in a loop formed by the third light emitting unit 33C of the semiconductor light emitting element 30, the third switching element 111, and the third capacitor 112, and the fourth current path in a loop formed by the fourth light emitting unit 33D of the semiconductor light emitting element 30, the fourth switching element 121, and the fourth capacitor 122.

[0269] (2-4) There are provided a plurality of third capacitors 112 and a plurality of fourth capacitors 122. The plurality of third capacitors 112 are connected in parallel with one another. The plurality of fourth capacitors 122 are connected in parallel with one another.

[0270] According to this configuration, since the multiple third capacitors 112 are connected in parallel with each other, the total inductance of the multiple third capacitors 112 can be reduced below the inductance of each of the third capacitors 112. Furthermore, since the multiple fourth capacitors 122 are connected in parallel with each other, the total inductance of the multiple fourth capacitors 122 can be reduced below the inductance of each of the fourth capacitors 122.

[0271] (2-5) The multiple third capacitors 112 are arranged spaced apart from each other in the Y direction. The multiple fourth capacitors 122 are arranged spaced apart from each other in the Y direction. With this configuration, the arrangement direction (Y direction) of the multiple third capacitors 112 is perpendicular to the arrangement direction (X direction) of the semiconductor light-emitting element 30, the third switching element 111, and the third capacitor 112 in a planar view. Therefore, the length of the loop-shaped third current path formed by the third light-emitting unit 33C of the semiconductor light-emitting element 30, the third switching element 111, and the third capacitor 112 can be shortened. The arrangement direction (Y direction) of the multiple fourth capacitors 122 is perpendicular to the arrangement direction (X direction) of the semiconductor light-emitting element 30, the fourth switching element 121, and the fourth capacitor 122 in a planar view. Therefore, the length of the loop-shaped fourth current path formed by the fourth light-emitting unit 33D of the semiconductor light-emitting element 30, the fourth switching element 121, and the fourth capacitor 122 can be shortened.

[0272] (2-6) The semiconductor light emitting device 10 further includes a third protection diode 103 connected in anti-parallel to the third light emitting portion 33C, and a fourth protection diode 104 connected in anti-parallel to the fourth light emitting portion 33D.

[0273] According to this configuration, the third light-emitting portion 33C and the fourth light-emitting portion 33D can be individually protected by the third protection diode 103 and the fourth protection diode 104. (2-7) The third protection diode 103 is disposed on the opposite side of the semiconductor light-emitting element 30 with respect to the third switching element 111 in the X direction. The fourth protection diode 104 is disposed on the opposite side of the semiconductor light-emitting element 30 with respect to the fourth switching element 121 in the X direction. The third protection diode 103 is disposed spaced apart from the third capacitor 112 in the Y direction. The fourth protection diode 104 is disposed spaced apart from the fourth capacitor 122 in the Y direction.

[0274] According to this configuration, the length of the loop-shaped third current path formed by the semiconductor light emitting element 30, the third switching element 111, and the third capacitor 112 can be shortened compared to a configuration in which the third protection diode 103 is arranged between the semiconductor light emitting element 30 and the third switching element 111 or between the third switching element 111 and the third capacitor 112. Furthermore, the length of the loop-shaped fourth current path formed by the semiconductor light emitting element 30, the fourth switching element 121, and the fourth capacitor 122 can be shortened compared to a configuration in which the fourth protection diode 104 is arranged between the semiconductor light emitting element 30 and the fourth switching element 121 or between the fourth switching element 121 and the fourth capacitor 122.

[0275] (2-8) The region where the plurality of first vias 161B are formed is arranged at a position overlapping the region where the plurality of first vias 161A are formed when viewed from the X direction. The region where the plurality of first vias 161C are formed is arranged at a position overlapping the region where the plurality of first vias 161A are formed when viewed from the X direction.

[0276] With this configuration, among the loops of the third current path in which current flows in the order of the first electrode 112A of the third capacitor 112, the drain electrode 111D and source electrode 111S of the third switching element 111, the third element front surface electrode 34C and back surface electrode 35 of the semiconductor light emitting element 30, and the second electrode 112B of the third capacitor 112, the path through the first intermediate electrode 151 is a path along the X direction. Therefore, the loop of the third current path can be made smaller, thereby reducing the inductance of the third current path. Furthermore, among the loops of the fourth current path in which current flows in the order of the first electrode 122A of the fourth capacitor 122, the drain electrode 121D and source electrode 121S of the fourth switching element 121, the fourth element front surface electrode 34D and back surface electrode 35 of the semiconductor light emitting element 30, and the second electrode 122B of the fourth capacitor 122, the path through the first intermediate electrode 151 is a path along the X direction. Therefore, the loop of the fourth current path can be made smaller, and the inductance of the fourth current path can be reduced.

[0277] (2-9) The third switching element 111 is disposed at a position overlapping the third light-emitting portion 33C of the semiconductor light-emitting element 30 when viewed from the X direction. The fourth switching element 121 is disposed at a position overlapping the fourth light-emitting portion 33D of the semiconductor light-emitting element 30 when viewed from the X direction.

[0278] According to this configuration, the distance between the third switching element 111 and the semiconductor light emitting element 30 can be shortened compared to a configuration in which the third switching element 111 is disposed at a position offset in the Y direction with respect to the semiconductor light emitting element 30. Therefore, when the source electrode 111S of the third switching element 111 and the third element surface electrode 34C of the semiconductor light emitting element 30 are connected by a wire W1, the length of the wire W1 can be shortened. Compared to a configuration in which the fourth switching element 121 is disposed at a position offset in the Y direction with respect to the semiconductor light emitting element 30, the distance between the fourth switching element 121 and the semiconductor light emitting element 30 can be shortened. Therefore, when the source electrode 121S of the fourth switching element 121 and the fourth element surface electrode 34D of the semiconductor light emitting element 30 are connected by a wire W1, the length of the wire W1 can be shortened.

[0279] 12 to 15, a semiconductor light emitting device 10 according to a third embodiment will be described. The semiconductor light emitting device 10 according to the third embodiment differs from the semiconductor light emitting device 10 according to the first embodiment mainly in that it includes a first switching element 171 and a second switching element 181 instead of the first switching element 41 and the second switching element 51. Below, differences from the first embodiment will be described in detail, and components common to the first embodiment will be denoted by the same reference numerals and their description may be omitted.

[0280] Fig. 12 shows a schematic planar structure of the semiconductor light-emitting device 10 of the third embodiment. Fig. 13 shows a schematic back surface structure of the semiconductor light-emitting device 10 of Fig. 12. Fig. 14 shows a schematic cross-sectional structure of the semiconductor light-emitting device 10 taken along line F14-F14 in Fig. 12. Fig. 15 shows a schematic cross-sectional structure of the semiconductor light-emitting device 10 taken along line F15-F15 in Fig. 12. The double-dashed line frames shown in Figs. 12 and 13 indicate openings formed in front resist 29A and back resist 29B (see Fig. 14).

[0281] 12, similar to the first embodiment, the semiconductor light emitting device 10 of the third embodiment includes a first drive circuit 40 and a second drive circuit 50. In other words, the circuit configuration of the semiconductor light emitting device 10 is similar to that of the first embodiment.

[0282] The first drive circuit 40 includes a first switching element 171 and a plurality of (six in the third embodiment) first capacitors 42. The second drive circuit 50 includes a second switching element 181 and a plurality of (six in the third embodiment) second capacitors 52. Unlike the first embodiment, the first switching element 171 and the second switching element 181 are horizontal transistors. In one example, the first switching element 171 and the second switching element 181 are transistors formed of a nitride semiconductor (e.g., gallium nitride (GaN)). An example of such a transistor may be a high electron mobility transistor (HEMT) using a nitride semiconductor. Note that the first switching element 171 and the second switching element 181 may be MOSFETs as long as they are horizontal transistors.

[0283] As described above, the configuration of the first switching element 171 and the second switching element 181 differs from that of the first embodiment, resulting in a different configuration of the substrate 20. More specifically, unlike the first embodiment, the substrate 20 does not include a front-side intermediate electrode 28C (see FIG. 4) and a back-side intermediate electrode 28D (see FIG. 3). In other words, the substrate 20 includes a single base material 27, a front-side electrode 28A, and a back-side electrode 28B. However, the configurations of the front-side electrode 28A and the back-side electrode 28B differ from those of the first embodiment. The detailed configurations of the front-side electrode 28A and the back-side electrode 28B will be described below.

[0284] Surface electrode 28A is formed on the substrate surface (substrate surface 21) of one substrate 27. Surface electrode 28A includes first surface electrodes 191A and 191B, second surface electrodes 192A, 192B, 192C, and 192D, third surface electrodes 193A and 193B, and fourth surface electrodes 194A and 194B.

[0285] The first surface electrode 191A and the first surface electrode 191B are arranged at both ends in the Y direction of the substrate surface 21. The first surface electrode 191A is an electrode on which the semiconductor light emitting element 30 is mounted. The first surface electrode 191A is an electrode electrically connected to the element back surface electrode 35 (see FIG. 14 ), which serves as the cathode of the semiconductor light emitting element 30. The first surface electrode 191B is an electrode electrically connected to the first surface electrode 191A.

[0286] The first surface electrode 191A is an electrode extending in the X direction at a position adjacent to the third substrate side surface 25 in the Y direction. The first surface electrode 191A is formed over substantially the entire substrate surface 21 in the X direction. The maximum dimension of the first surface electrode 191A in the Y direction is equal to or greater than one-quarter of the dimension of the substrate surface 21 in the Y direction. The maximum dimension of the first surface electrode 191A in the Y direction is smaller than one-third of the dimension of the substrate surface 21 in the Y direction.

[0287] In a plan view, of both ends of the first surface electrode 191A in the Y direction, the end closer to the fourth substrate side surface 26 includes a recess 191AA recessed toward the third substrate side surface 25 at the center in the X direction. In one example, the shape of the recess 191AA in a plan view is a rectangular recess. The X direction dimension of the recess 191AA is greater than ½ of the X direction dimension of the substrate surface 21. The X direction dimension of the recess 191AA is less than ¾ of the X direction dimension of the substrate surface 21. Here, the X direction dimension of the recess 191AA can be defined by the distance in the X direction between the X direction ends of the side surfaces that make up the recess 191AA.

[0288] The first surface electrode 191B extends in the X direction at a position adjacent to the fourth substrate side surface 26 in the Y direction. The first surface electrode 191B is formed over substantially the entire substrate surface 21 in the X direction. The maximum dimension in the Y direction of the first surface electrode 191B is smaller than the maximum dimension in the Y direction of the first surface electrode 191A. The maximum dimension in the Y direction of the first surface electrode 191B is larger than half the maximum dimension in the Y direction of the first surface electrode 191A.

[0289] In a plan view, of both ends of the first surface electrode 191B in the Y direction, the end closer to the third substrate side surface 25 includes a recess 191BA that is recessed toward the fourth substrate side surface 26 at the center in the X direction. In one example, the shape of the recess 191BA in a plan view is a rectangular recess. The dimension of the recess 191BA in the X direction is larger than the dimension of the recess 191AA in the X direction. Here, the dimension of the recess 191BA in the X direction can be defined by the distance in the X direction between the side surfaces at both ends in the X direction that make up the recess 191BA.

[0290] Between the first surface electrode 191A and the first surface electrode 191B in the Y direction, second surface electrodes 192A, 192B, 192C, and 192D, third surface electrodes 193A and 193B, and fourth surface electrodes 194A and 194B are arranged.

[0291] The second surface electrodes 192A and 192C, the third surface electrode 193A, the fourth surface electrode 194A, and the first surface electrode 191B are electrodes electrically connected to the first drive circuit 40. The second surface electrodes 192B and 192D, the third surface electrode 193B, the fourth surface electrode 194B, and the first surface electrode 191B are electrodes electrically connected to the second drive circuit 50.

[0292] The second surface electrodes 192A, 192C, the third surface electrode 193A, and the fourth surface electrode 194A are arranged closer to the first substrate side surface 23 than the imaginary center line VC, and the second surface electrodes 192B, 192D, the third surface electrode 193B, and the fourth surface electrode 194B are arranged closer to the second substrate side surface 24 than the imaginary center line VC.

[0293] The second surface electrode 192A is an electrode electrically connected to the drain electrode 171D of the first switching element 171 of the first drive circuit 40. The second surface electrode 192C is an electrode electrically connected to the second surface electrode 192A. The second surface electrode 192B is an electrode electrically connected to the drain electrode 181D of the second switching element 181 of the second drive circuit 50. The second surface electrode 192D is an electrode electrically connected to the second surface electrode 192B.

[0294] A plurality of second surface electrodes 192A (three in the third embodiment) are provided. Each second surface electrode 192A is formed in an oval shape extending in the Y direction. The plurality of second surface electrodes 192A are arranged at the same positions in the Y direction and spaced apart from each other in the X direction. The plurality of second surface electrodes 192A are arranged between the imaginary center line VC and the first substrate side surface 23 in the X direction, closer to the imaginary center line VC.

[0295] A plurality of second surface electrodes 192B (three in the third embodiment) are provided. Each second surface electrode 192B has the same shape and size as the second surface electrode 192A. The plurality of second surface electrodes 192B are symmetrical to the plurality of second surface electrodes 192A with respect to the imaginary center line VC.

[0296] Each of the second surface electrodes 192A and 192B is disposed between the first surface electrodes 191A and 191B and closer to the first surface electrode 191A in the Y direction. The end of each of the second surface electrodes 192A and 192B closer to the first surface electrode 191A in the Y direction is disposed within a recess 191AA in the Y direction.

[0297] The second surface electrodes 192C and 192D are arranged closer to the fourth substrate side surface 26 in the Y direction than the second surface electrodes 192A and 192B. The second surface electrode 192C is formed in a rectangular shape with its longitudinal direction in the X direction and its lateral direction in the Y direction in a plan view. The dimension of the second surface electrode 192C in the X direction is greater than one-third of the dimension of the substrate surface 21 in the X direction and less than one-half of the dimension of the substrate surface 21 in the X direction. Of both end portions of the second surface electrode 192C in the X direction, the end portion closer to the first substrate side surface 23 is arranged closer to the first substrate side surface 23 than the second surface electrode 192A of the multiple second surface electrodes 192A that is closest to the first substrate side surface 23.

[0298] The second surface electrode 192D is symmetrical to the multiple second surface electrodes 192C with respect to the imaginary center line VC. Of both ends of the second surface electrode 192D in the X direction, the end closer to the second substrate side surface 24 is positioned closer to the second substrate side surface 24 than the second surface electrode 192B, which is closest to the second substrate side surface 24, among the multiple second surface electrodes 192B. The second surface electrodes 192C and 192D are positioned within the recess 191BA in the X direction. Parts of the second surface electrodes 192C and 192D in the Y direction are positioned within the recess 191BA in the Y direction.

[0299] The third surface electrode 193A is an electrode electrically connected to the source electrode 171S of the first switching element 171. The third surface electrode 193B is an electrode electrically connected to the source electrode 181S of the second switching element 181. The fourth surface electrode 194A is an electrode electrically connected to the gate electrode 171G of the first switching element 171. The fourth surface electrode 194B is an electrode electrically connected to the gate electrode 181G of the second switching element 181.

[0300] The third surface electrodes 193A and 193B are disposed between the first surface electrode 191A and the second surface electrodes 192C and 192D in the Y direction. The third surface electrode 193A is formed so as to surround the plurality of second surface electrodes 192A in a plan view. Of both ends of the third surface electrode 193A in the Y direction, the end closer to the first surface electrode 191A is disposed within the recess 191AA. This end is disposed closer to the first surface electrode 191A than the plurality of second surface electrodes 192A.

[0301] A recess 193AA facing the recess 191BA is formed in the end of the third surface electrode 193A in the Y direction that is closer to the first surface electrode 191B. A part of the second surface electrode 192C in the Y direction is disposed in the recess 193AA.

[0302] The third surface electrode 193A includes a detour portion 193AB that surrounds the fourth surface electrode 194A. The detour portion 193AB detours around the fourth surface electrode 194A and faces the second surface electrode 192A in the X direction at a position closer to the first surface electrode 191A than the fourth surface electrode 194A in the Y direction.

[0303] The fourth surface electrode 194A is arranged closer to the first substrate side surface 23 in the X direction than the multiple second surface electrodes 192A. The fourth surface electrode 194A is arranged in a position facing the portion of the second surface electrode 192A closer to the third surface electrode 193A in the X direction. The fourth surface electrode 194A is arranged in an area surrounded by the second surface electrode 192A and the detour portion 193AB. The fourth surface electrode 194A is formed in a rectangular shape with the X direction as the longitudinal direction and the Y direction as the lateral direction.

[0304] The third surface electrode 193B is formed so as to surround the plurality of second surface electrodes 192B in a plan view. The third surface electrode 193B has a shape that is different from the shape of the third surface electrode 193A, which is line-symmetrical with respect to the imaginary center line VC. Of both ends of the third surface electrode 193B in the Y direction, the end closer to the first surface electrode 191A is disposed within the recess 191AA. This end is disposed closer to the first surface electrode 191A than the plurality of second surface electrodes 192B.

[0305] Of both ends of third surface electrode 193B in the Y direction, the end closer to first surface electrode 191B has a recess 193BA facing recess 191BA. A portion of second surface electrode 192D in the Y direction is disposed in recess 193BA. In this way, second surface electrodes 192C and 192D are disposed within the region surrounded by recess 191BA, recess 193AA, and recess 193BA in plan view.

[0306] The fourth surface electrode 194B is arranged closer to the second substrate side surface 24 in the X direction than the multiple second surface electrodes 192B. The fourth surface electrode 194B is arranged in a position facing the portion of the second surface electrode 192B closer to the first surface electrode 191A in the X direction. In other words, the fourth surface electrode 194B is arranged closer to the first surface electrode 191A in the Y direction than a position that is linearly symmetrical to the fourth surface electrode 194A about the imaginary center line VC. The fourth surface electrode 194B is formed in a rectangular shape with its longitudinal direction in the X direction and its lateral direction in the Y direction. The dimension of the fourth surface electrode 194B in the X direction is greater than the dimension of the fourth surface electrode 194A in the X direction.

[0307] 13 , the back surface electrode 28B is formed on the back surface (substrate back surface 22) of one base material 27. The back surface electrode 28B includes a first back surface electrode 201, second back surface electrodes 202A, 202B, 202C, and 202D, third back surface electrodes 203A and 203B, and fourth back surface electrodes 204A and 204B.

[0308] The first back surface electrode 201 is an electrode electrically connected to the first surface electrodes 191A and 191B (see FIG. 12 ). The first back surface electrode 201 is disposed at a position overlapping the first surface electrodes 191A and 191B in a plan view. In a plan view, the area of ​​the first back surface electrode 201 is larger than the areas of the second back surface electrodes 202A, 202B, 202C, and 202D, the third back surface electrodes 203A and 203B, and the fourth back surface electrodes 204A and 204B. The area of ​​the first back surface electrode 201 is larger than the combined area of ​​the third back surface electrodes 203A and 203B, and the fourth back surface electrodes 204A and 204B. In one example, the first back surface electrode 201 is formed over most of the substrate back surface 22.

[0309] The first back surface electrode 201 includes two recesses 201A and 201B recessed in the X direction. The recess 201A is provided at one of both X direction end portions of the first back surface electrode 201 that is closer to the first substrate side surface 23. The recess 201A is recessed from this end portion toward the second substrate side surface 24. The recess 201B is provided at one of both X direction end portions of the first back surface electrode 201 that is closer to the second substrate side surface 24. The recess 201B is recessed from this end portion toward the first substrate side surface 23. The recesses 201A and 201B are formed in a rectangular recess shape with the Y direction as the longitudinal direction and the X direction as the lateral direction in a plan view. The recesses 201A and 201B are formed between the third substrate side surface 25 and the fourth substrate side surface 26 in the Y direction, closer to the fourth substrate side surface 26. The Y-direction dimension of the recesses 201A and 201B is approximately half the Y-direction dimension of the substrate rear surface 22. Here, the Y-direction dimension of the recesses 201A and 201B can be defined as the distance between the Y-direction ends of the side surfaces of the recesses 201A and 201B in the Y direction.

[0310] The first back surface electrode 201 has a plurality of first openings 201C and a plurality of second openings 201D. Each of the first openings 201C and second openings 201D has an oval shape with the Y direction as the longitudinal direction and the X direction as the lateral direction in a plan view. Each of the first openings 201C and second openings 201D has the same size. In one example, the Y direction dimension of each of the first openings 201C and second openings 201D is slightly smaller than the Y direction dimension of the recesses 201A and 201B.

[0311] The multiple first openings 201C are arranged closer to the first substrate side surface 23 than the imaginary center line VC in the X direction. The multiple first openings 201C are arranged at the same positions as each other in the Y direction and spaced apart from each other in the X direction.

[0312] The second openings 201D are arranged closer to the second substrate side surface 24 than the imaginary center line VC in the X direction. The second openings 201D are arranged at the same positions in the Y direction and spaced apart from each other in the X direction. The positions of the second openings 201D in the Y direction are the same as the positions of the first openings 201C in the Y direction. In one example, the second openings 201D are arranged in positions that are line-symmetrical to the first openings 201C with respect to the imaginary center line VC.

[0313] Each first opening 201C and each second opening 201D is disposed between recesses 201A and 201B in the X direction. Each first opening 201C and each second opening 201D is disposed closer to third substrate side surface 25 than recesses 201A and 201B in the Y direction. Therefore, of both end portions of each first opening 201C and each second opening 201D in the Y direction, the end portion closer to third substrate side surface 25 is disposed closer to third substrate side surface 25 than recesses 201A and 201B.

[0314] A plurality of second rear surface electrodes 202A (three in the third embodiment) are provided corresponding to the number of first openings 201C. The second rear surface electrodes 202A are electrodes that are individually electrically connected to the second surface electrodes 192A (see FIG. 12). The second rear surface electrodes 202A are electrodes that are individually electrically connected to the second surface electrodes 192C (see FIG. 12). Therefore, it can be said that the second rear surface electrodes 202A are electrically connected to each other. The second rear surface electrodes 202A are arranged at positions that individually overlap the second surface electrodes 192A in a plan view.

[0315] Each second back surface electrode 202A is formed in an oval shape with the Y direction as its longitudinal direction and the X direction as its transverse direction. The Y direction length of each second back surface electrode 202A is longer than the Y direction length of each second surface electrode 192A. The multiple second back surface electrodes 202A extend in the Y direction so as to overlap with the second surface electrodes 192C in a planar view. In other words, each second back surface electrode 202A is formed to have a length that overlaps with both the second surface electrodes 192A and the second surface electrodes 192C in a planar view.

[0316] A plurality of second rear surface electrodes 202B (three in the third embodiment) are provided corresponding to the number of second openings 201D. The second rear surface electrodes 202B are electrodes that are individually electrically connected to the second surface electrodes 192B (see FIG. 12). The second rear surface electrodes 202B are electrodes that are individually electrically connected to the second surface electrodes 192D (see FIG. 12). Therefore, it can be said that the second rear surface electrodes 202B are electrically connected to each other. The second rear surface electrodes 202B are arranged at positions that individually overlap the second surface electrodes 192B in a plan view.

[0317] Each second back surface electrode 202B is formed in an oval shape with the Y direction as its longitudinal direction and the X direction as its transverse direction. The Y direction length of each second back surface electrode 202B is longer than the Y direction length of each second surface electrode 192B. The multiple second back surface electrodes 202B extend in the Y direction so as to overlap with the second surface electrodes 192D in a planar view. In other words, each second back surface electrode 202B is formed to have a length that overlaps with both the second surface electrodes 192B and the second surface electrodes 192D in a planar view. The size of each second back surface electrode 202B is the same as the size of each second back surface electrode 202A.

[0318] A second back surface electrode 202C, a third back surface electrode 203A, and a fourth back surface electrode 204A are arranged in the recess 201A. A second back surface electrode 202D, a third back surface electrode 203B, and a fourth back surface electrode 204B are arranged in the recess 201B. A second back surface electrode 202A is arranged in each first opening 201C. A second back surface electrode 202B is arranged in each second opening 201D.

[0319] The second back surface electrode 202C is an electrode electrically connected to the second surface electrode 192C (see FIG. 12 ). Therefore, it can be said that the second back surface electrode 202C is electrically connected to the second back surface electrode 202A. The second back surface electrode 202C is arranged closer to the fourth substrate side surface 26 than the third back surface electrode 203A and the fourth back surface electrode 204A. The second back surface electrode 202C is arranged at a position overlapping the second surface electrode 192C in a plan view. The second back surface electrode 202C is formed in a rectangular shape with the X direction as the longitudinal direction and the Y direction as the lateral direction in a plan view.

[0320] The third back surface electrode 203A is an electrode electrically connected to the third surface electrode 193A (see FIG. 12 ). The third back surface electrode 203A is disposed between the second back surface electrode 202C and the fourth back surface electrode 204A in the Y direction. The third back surface electrode 203A is disposed at a position overlapping the third surface electrode 193A in a plan view. A recess is formed in one of the four corners of the third back surface electrode 203A, the corner closest to the second substrate side surface 24 and the third substrate side surface 25.

[0321] A portion of the fourth rear surface electrode 204A is disposed in the recessed portion. The fourth rear surface electrode 204A is an electrode electrically connected to the fourth front surface electrode 194A. The fourth rear surface electrode 204A is disposed at a position overlapping the fourth front surface electrode 194A in a plan view. The fourth rear surface electrode 204A is formed in an L-shape in a plan view.

[0322] The second back surface electrode 202D is an electrode electrically connected to the second surface electrode 192D (see FIG. 12 ). Therefore, it can be said that the second back surface electrode 202D is electrically connected to the second back surface electrode 202B. The second back surface electrode 202D is arranged at a position overlapping the second surface electrode 192D in a plan view. The second back surface electrode 202D is arranged closer to the fourth substrate side surface 26 than the third back surface electrode 203B and the fourth back surface electrode 204B. The second back surface electrode 202D is formed in a rectangular shape with the X direction as the longitudinal direction and the Y direction as the lateral direction in a plan view. The shape and size of the second back surface electrode 202D are the same as those of the second back surface electrode 202C.

[0323] The third back surface electrode 203B is an electrode electrically connected to the third surface electrode 193B (see FIG. 12 ). The third back surface electrode 203B is disposed between the second back surface electrode 202D and the fourth back surface electrode 204B in the Y direction. The third back surface electrode 203B is disposed at a position overlapping the third surface electrode 193B in a plan view. The third back surface electrode 203B is formed in a rectangular shape with the X direction as the longitudinal direction and the Y direction as the lateral direction in a plan view. The dimension of the third back surface electrode 203B in the Y direction is larger than the dimension of the second back surface electrode 202D in the Y direction.

[0324] The fourth back surface electrode 204B is an electrode electrically connected to the fourth surface electrode 194B (see FIG. 12 ). The fourth back surface electrode 204B is disposed at a position overlapping the fourth surface electrode 194B in a plan view. The fourth back surface electrode 204B is formed in a rectangular shape with the X direction as the longitudinal direction and the Y direction as the lateral direction in a plan view. The dimension of the fourth back surface electrode 204B in the Y direction is smaller than the dimension of the second back surface electrode 202D in the Y direction.

[0325] 12 and 13 , the substrate 20 includes first vias 211A, 211B, and 211C, second vias 212A and 212B, third vias 213A and 213B, and fourth vias 214A and 214B. The first vias 211A, 211B, and 211C, the second vias 212A and 212B, the third vias 213A and 213B, and the fourth vias 214A and 214B penetrate the base material 27 in the Z direction. The first vias 211A, 211B, and 211C, the second vias 212A and 212B, the third vias 213A and 213B, and the fourth vias 214A and 214B are formed from a material containing one or more appropriately selected from the group consisting of Ti, TiN, Au, Ag, Cu, Al, and W.

[0326] A plurality of first vias 211A, 211B, and 211C are provided. The first via 211A is electrically connected to the first surface electrode 191A and the first back surface electrode 201. This electrically connects the first surface electrode 191A and the first back surface electrode 201 to each other. The first vias 211B and 211C are electrically connected to the first surface electrode 191B and the first back surface electrode 201. This electrically connects the first surface electrode 191B and the first back surface electrode 201 to each other. In this way, the first surface electrode 191A and the first surface electrode 191B are electrically connected to each other via the first via 211A, the first back surface electrode 201, and the first vias 211B and 211C.

[0327] The multiple first vias 211A are arranged at the center of the first surface electrode 191A in the X direction and closer to the third substrate side surface 25 of the first surface electrode 191A in the Y direction. The multiple first vias 211A are arranged at a distance from each other in the X and Y directions. The number of first vias 211A arranged in the X direction is greater than the number of first vias 211A arranged in the Y direction. In a planar view, the area in which the multiple first vias 211A are formed is larger than the area of ​​the semiconductor light emitting element 30. Therefore, some of the multiple first vias 211A are provided outward from the semiconductor light emitting element 30 in a planar view.

[0328] The multiple first vias 211B are arranged in the first surface electrode 191B closer to the first substrate side surface 23 than the imaginary center line VC in the X direction. The multiple first vias 211B are arranged in the first surface electrode 191B closer to the fourth substrate side surface 26 in the Y direction. The multiple first vias 211B are arranged at a distance from each other in the X and Y directions. The number of first vias 211B arranged in the X direction is greater than the number of first vias 211B arranged in the Y direction.

[0329] The multiple first vias 211C are arranged in the X direction on the first surface electrode 191B closer to the second substrate side surface 24 than the imaginary center line VC. The multiple first vias 211C are arranged in the Y direction on the first surface electrode 191B closer to the fourth substrate side surface 26. The multiple first vias 211C are arranged at a distance from each other in the X and Y directions. The number of first vias 211C arranged in the X direction is greater than the number of first vias 211C arranged in the Y direction. In one example, the number and arrangement of the multiple first vias 211C are the same as those of the first vias 211B.

[0330] A plurality of second vias 212A are provided. Some of the plurality of second vias 212A are electrically connected to the plurality of second surface electrodes 192A and the plurality of second back surface electrodes 202A, respectively. As a result, the plurality of second surface electrodes 192A and the plurality of second back surface electrodes 202A are electrically connected to each other. Another portion of the plurality of second vias 212A is electrically connected to the second surface electrode 192C and the plurality of second back surface electrodes 202A, respectively. As a result, the second surface electrode 192C and the plurality of second back surface electrodes 202A are electrically connected to each other. In this manner, the plurality of second surface electrodes 192A and the second surface electrode 192C are electrically connected to each other via the second vias 212A and the plurality of second back surface electrodes 202A. Furthermore, yet another portion of the plurality of second vias 212A is electrically connected to the second surface electrode 192C and the second back surface electrode 202C, respectively. As a result, the second surface electrode 192C and the second back surface electrode 202C are electrically connected to each other.

[0331] A plurality of second vias 212B are provided. Some of the plurality of second vias 212B are electrically connected to the plurality of second surface electrodes 192B and the plurality of second back surface electrodes 202B individually. As a result, the plurality of second surface electrodes 192B and the plurality of second back surface electrodes 202B are electrically connected to each other. Furthermore, another portion of the plurality of second vias 212B is electrically connected to the second surface electrode 192D and the plurality of second back surface electrodes 202B individually. As a result, the second surface electrode 192D and the plurality of second back surface electrodes 202B are electrically connected to each other. In this manner, the plurality of second surface electrodes 192B and the second surface electrode 192D are electrically connected to each other via the second vias 212B and the plurality of second back surface electrodes 202B. Furthermore, yet another portion of the plurality of second vias 212B is electrically connected to the second surface electrode 192D and the second back surface electrode 202D individually. As a result, the second surface electrode 192D and the second back surface electrode 202D are electrically connected to each other.

[0332] A plurality of third vias 213A are provided. The third vias 213A are electrically connected to the third front surface electrode 193A and the third rear surface electrode 203A. As a result, the third front surface electrode 193A and the third rear surface electrode 203A are electrically connected to each other.

[0333] A plurality of third vias 213B are provided. The third vias 213B are electrically connected to the third front surface electrode 193B and the third rear surface electrode 203B. As a result, the third front surface electrode 193B and the third rear surface electrode 203B are electrically connected to each other.

[0334] One fourth via 214A is provided. The fourth via 214A is electrically connected to the fourth front surface electrode 194A and the fourth rear surface electrode 204A. This electrically connects the fourth front surface electrode 194A and the fourth rear surface electrode 204A to each other.

[0335] One fourth via 214B is provided. The fourth via 214B is electrically connected to the fourth front surface electrode 194B and the fourth rear surface electrode 204B. This electrically connects the fourth front surface electrode 194B and the fourth rear surface electrode 204B to each other.

[0336] 12, semiconductor light-emitting elements 30, first drive circuits 40, and second drive circuits 50 are mounted on a plurality of surface electrodes 28A. Detailed configurations and embodiments of the semiconductor light-emitting elements 30, first drive circuits 40, and second drive circuits 50 will be described below. Note that components common to the first embodiment are designated by the same reference numerals, and their description may be omitted.

[0337] The semiconductor light emitting element 30 is mounted on the first surface electrode 191A. More specifically, as shown in Fig. 14, the semiconductor light emitting element 30 is joined to the first surface electrode 191A with a conductive bonding material SD. As shown in Fig. 12, the semiconductor light emitting element 30 is disposed at the center of the first surface electrode 191A in the X direction and in a portion of the first surface electrode 191A closer to the third substrate side surface 25 in the Y direction.

[0338] The semiconductor light emitting element 30 includes a plurality of (eight in the third embodiment) light emitting portions 33. The light emitting portions 33 are aligned in the X direction. More specifically, four light emitting portions 33 are arranged on each side of the imaginary center line VC. Here, each of the four light emitting portions 33 closer to the first substrate side surface 23 than the imaginary center line VC is referred to as a "first light emitting portion 33A," and each of the four light emitting portions 33 closer to the second substrate side surface 24 than the imaginary center line VC is referred to as a "second light emitting portion 33B." The semiconductor light emitting element 30 includes a plurality of (four in the third embodiment) first element surface electrodes 34A corresponding to the first light emitting portions 33A and a plurality of (four in the third embodiment) second element surface electrodes 34B corresponding to the second light emitting portions 33B. The first element surface electrode 34A is an example of a "first anode electrode of the semiconductor light emitting element," and the second element surface electrode 34B is an example of a "second anode electrode of the semiconductor light emitting element."

[0339] The plurality of first element surface electrodes 34A and the third surface electrode 193A are electrically connected by a plurality of wires W5. The plurality of wires W5 are individually electrically connected to the plurality of first element surface electrodes 34A. Meanwhile, the plurality of wires W5 are electrically connected to the third surface electrode 193A. Therefore, each of the plurality of first element surface electrodes 34A is electrically connected to the third surface electrode 193A. The plurality of wires W5 are connected to a portion of the third surface electrode 193A that is disposed within the recess 191AA of the first surface electrode 191A. The plurality of wires W5 individually connected to the plurality of first element surface electrodes 34A are formed so that their lengths are approximately equal to each other in a plan view, for example.

[0340] The second element surface electrodes 34B and the third surface electrode 193B are electrically connected by wires W5. The wires W5 are individually electrically connected to the second element surface electrodes 34B. Meanwhile, the wires W5 are electrically connected to the third surface electrode 193B. Therefore, each of the second element surface electrodes 34B is electrically connected to the third surface electrode 193B. The wires W5 are connected to a portion of the third surface electrode 193B that is disposed within the recess 191AA of the first surface electrode 191A. The wires W5 individually connected to the second element surface electrodes 34B are formed to have approximately the same length in a plan view, for example.

[0341] In one example, in a plan view, the total length of the multiple wires W5 individually connected to the multiple first element surface electrodes 34A is equal to the total length of the multiple wires W5 individually connected to the multiple second element surface electrodes 34B. Here, if the difference between the total length of the multiple wires W5 individually connected to the multiple first element surface electrodes 34A and the total length of the multiple wires W5 individually connected to the multiple second element surface electrodes 34B in a plan view is, for example, within 10% of the total length of the multiple wires W5 individually connected to the multiple first element surface electrodes 34A, it can be said that the total length of the multiple wires W5 individually connected to the multiple first element surface electrodes 34A is equal to the total length of the multiple wires W5 individually connected to the multiple second element surface electrodes 34B in a plan view.

[0342] The first switching element 171 is disposed at a position overlapping with the plurality of second surface electrodes 192A, third surface electrodes 193A, and fourth surface electrodes 194A in a plan view. The first switching element 171 is disposed closer to the fourth substrate side surface 26 than the plurality of wires W5 in the Y direction. The first switching element 171 is disposed closer to the third substrate side surface 25 than the second surface electrode 192C in the Y direction. The first switching element 171 is disposed closer to the imaginary center line VC between the imaginary center line VC and the first substrate side surface 23 in the X direction. The first switching element 171 includes a portion overlapping with the first light-emitting portion 33A of the semiconductor light-emitting element 30 when viewed from the Y direction. The first switching element 171 is formed in a rectangular plate shape with the thickness direction in the Z direction. The first switching element 171 is formed in a rectangular shape with the longitudinal direction in the X direction and the lateral direction in the Y direction when viewed from the Y direction.

[0343] The first switching element 171 has a second element front surface 171A and a second element back surface 171B facing opposite directions in the Z direction. The second element front surface 171A faces the same side as the substrate front surface 21, and the second element back surface 171B faces the same side as the substrate back surface 22. The first switching element 171 includes a plurality of drain electrodes 171D (three in the third embodiment), a plurality of source electrodes 171S (four in the third embodiment), and a gate electrode 171G. The plurality of drain electrodes 171D, the plurality of source electrodes 171S, and the gate electrode 171G are each formed on the second element back surface 171B of the first switching element 171. Each of the drain electrodes 171D, each of the source electrodes 171S, and the gate electrode 171G is formed in a rectangular shape with the Y direction as the longitudinal direction and the X direction as the lateral direction. Here, the second element back surface is an example of the "back surface of the first switching element."

[0344] The plurality of drain electrodes 171D are arranged at intervals from one another in the X direction. The plurality of source electrodes 171S are arranged at intervals from one another in the X direction. Of the plurality of source electrodes 171S, the source electrode 171S closest to the first substrate side surface 23 is formed so as to have a shorter length in the Y direction than the other source electrodes 171S. The length in the Y direction of the other source electrodes 171S is equal to the length in the Y direction of the drain electrode 171D.

[0345] The multiple drain electrodes 171D and the multiple source electrodes 171S are alternately arranged one by one in the X direction. In the example of FIG. 12 , the source electrode 171S, drain electrode 171D, source electrode 171S, drain electrode 171D, source electrode 171S, drain electrode 171D, source electrode 171S, drain electrode 171D, and source electrode 171S are arranged in this order from the end of the second element back surface 171B closest to the first substrate side surface 23 toward the end closest to the second substrate side surface 24. Therefore, both ends of the second element back surface 171B in the X direction are source electrodes 171S. A gate electrode 171G is arranged at the end of the second element back surface 171B closest to the first substrate side surface 23. The gate electrode 171G and the source electrode 171S closest to the first substrate side surface 23 are arranged spaced apart from each other in the Y direction. The gate electrode 171G is arranged closer to the fourth substrate side surface 26 than the source electrode 171S closest to the first substrate side surface 23. The length of the gate electrode 171G in the Y direction is shorter than the length of the drain electrode 171D. In one example, the length of the gate electrode 171G in the Y direction is equal to the length of the source electrode 171S closest to the first substrate side surface 23 in the Y direction.

[0346] The plurality of drain electrodes 171D are arranged at positions where they individually overlap the plurality of second surface electrodes 192A in a plan view. As shown in Fig. 15 , the plurality of drain electrodes 171D are individually joined to the plurality of second surface electrodes 192A with a conductive bonding material SD. As a result, the plurality of drain electrodes 171D are individually electrically connected to the plurality of second surface electrodes 192A.

[0347] Each of the source electrodes 171S is disposed at a position overlapping the third surface electrode 193A. As shown in Fig. 15, the source electrodes 171S are bonded to the third surface electrode 193A with a conductive bonding material SD. This electrically connects the source electrodes 171S to the third surface electrode 193A.

[0348] 12, the gate electrode 171G is disposed at a position overlapping the fourth surface electrode 194A. The gate electrode 171G is joined to the fourth surface electrode 194A by a conductive bonding material SD (not shown). This electrically connects the gate electrode 171G to the fourth surface electrode 194A.

[0349] A plurality of first capacitors 42 (six in the third embodiment) are provided. The plurality of first capacitors 42 are connected in parallel to one another. The plurality of first capacitors 42 are arranged spaced apart from one another in the X direction. Each first capacitor 42 is arranged to straddle the second surface electrode 192C and the first surface electrode 191B in the Y direction. Each first capacitor 42 is mounted on the second surface electrode 192C and the first surface electrode 191B. More specifically, as shown in FIG. 14 , each first capacitor 42 is individually bonded to the second surface electrode 192C and the first surface electrode 191B with a conductive bonding material SD. The first electrode 42A of each first capacitor 42 is bonded to the second surface electrode 192C. The second electrode 42B of each first capacitor 42 is bonded to the first surface electrode 191B. As a result, the first electrode 42A is electrically connected to the second surface electrode 192C, and the second electrode 42B is electrically connected to the first surface electrode 191B.

[0350] The multiple first capacitors 42 are arranged on the opposite side of the first switching element 171 from the semiconductor light emitting element 30 in the Y direction. In other words, the first switching element 171 is arranged between the semiconductor light emitting element 30 and the multiple first capacitors 42 in the Y direction. When viewed from the Y direction, the multiple first capacitors 42 are arranged in positions that overlap the first switching element 171.

[0351] Because the multiple second surface electrodes 192A are electrically connected to the second surface electrode 192C, the first electrode 42A of each first capacitor 42 is electrically connected to the multiple drain electrodes 171D of the first switching element 171. The multiple source electrodes 171S of the first switching element 171 are electrically connected to the multiple first element surface electrodes 34A via the third surface electrode 193A and the multiple wires W5. Because the first element surface electrode 34A constitutes the first anode electrode of the semiconductor light emitting element 30, it can be said that the first anode electrode is electrically connected to the source electrode 171S of the first switching element 171.

[0352] The second switching element 181 is positioned so as to overlap with the second surface electrodes 192B, the third surface electrode 193B, and the fourth surface electrode 194B in a plan view. The second switching element 181 is positioned closer to the fourth substrate side surface 26 than the wires W5 in the Y direction. The second switching element 181 is positioned closer to the third substrate side surface 25 than the second surface electrode 192D in the Y direction. The second switching element 181 is positioned closer to the imaginary center line VC between the imaginary center line VC and the second substrate side surface 24 in the X direction. The second switching element 181 includes a portion that overlaps with the second light-emitting unit 33B when viewed from the Y direction. The second switching element 181 is formed in a rectangular plate shape with the thickness direction in the Z direction. The second switching element 181 is formed in a rectangular shape with the X direction as the longitudinal direction and the Y direction as the lateral direction in a plan view. The shape and size of the second switching element 181 are the same as those of the first switching element 171.

[0353] The distance D1 in the Y direction between the semiconductor light emitting element 30 and the first switching element 171 is equal to the distance D2 in the Y direction between the semiconductor light emitting element 30 and the second switching element 181. Here, if the difference between the distance D1 and the distance D2 is, for example, within 10% of the distance D1, it can be said that the distance D1 is equal to the distance D2.

[0354] The second switching element 181 includes a second element front surface 181A and a second element back surface 181B facing opposite directions in the Z direction. The second element front surface 181A faces the same side as the substrate front surface 21, and the second element back surface 181B faces the same side as the substrate back surface 22. The second switching element 181 includes a plurality of drain electrodes 181D (three in the third embodiment), a plurality of source electrodes 181S (four in the third embodiment), and a gate electrode 181G. Each of the drain electrodes 181D, source electrodes 181S, and gate electrodes 181G is formed on the second element back surface 181B. Each of the drain electrodes 181D, source electrodes 181S, and gate electrodes 181G is formed in a rectangular shape with the Y direction as the longitudinal direction and the X direction as the lateral direction. Here, the second element back surface 181B is an example of the "back surface of the second switching element."

[0355] The plurality of drain electrodes 181D are arranged at intervals from one another in the X direction. The plurality of source electrodes 181S are arranged at intervals from one another in the X direction. Of the plurality of source electrodes 181S, the source electrode 181S closest to the second substrate side surface 24 is formed so as to have a shorter length in the Y direction than the other source electrodes 181S. The length in the Y direction of this other source electrode 181S is equal to the length in the Y direction of the drain electrode 181D.

[0356] The multiple drain electrodes 181D and the multiple source electrodes 181S are alternately arranged one by one in the X direction. In the example of FIG. 12 , the source electrode 181S, drain electrode 181D, source electrode 181S, drain electrode 181D, source electrode 181S, drain electrode 181D, source electrode 181S, drain electrode 181D, and source electrode 181S are arranged in this order from the end of the second element back surface 181B closest to the second substrate side surface 24 toward the end closest to the first substrate side surface 23. Therefore, both ends of the second element back surface 181B in the X direction are source electrodes 181S. A gate electrode 181G is arranged at the end of the second element back surface 181B closest to the second substrate side surface 24. The gate electrode 181G and the source electrode 181S closest to the second substrate side surface 24 are arranged spaced apart from each other in the Y direction. The gate electrode 181G is arranged closer to the third substrate side surface 25 than the source electrode 181S closest to the second substrate side surface 24. The length of the gate electrode 181G in the Y direction is shorter than the length of the drain electrode 181D. In one example, the length of the gate electrode 181G in the Y direction is equal to the length of the source electrode 181S closest to the second substrate side surface 24 in the Y direction.

[0357] The plurality of drain electrodes 181D are disposed at positions that individually overlap the plurality of second surface electrodes 192B in a plan view. As shown in Fig. 15, the plurality of drain electrodes 181D are individually joined to the plurality of second surface electrodes 192B by a conductive bonding material SD. As a result, the plurality of drain electrodes 181D are individually electrically connected to the plurality of second surface electrodes 192B.

[0358] Each of the source electrodes 181S is disposed at a position overlapping with the third surface electrode 193B. As shown in Fig. 15, the source electrodes 181S are bonded to the third surface electrode 193B with a conductive bonding material SD. This electrically connects the source electrodes 181S to the third surface electrode 193B.

[0359] 12, the gate electrode 181G is disposed at a position overlapping with the fourth surface electrode 194B. The gate electrode 181G is joined to the fourth surface electrode 194B by a conductive bonding material SD. As a result, the gate electrode 181G is electrically connected to the fourth surface electrode 194B.

[0360] A plurality of second capacitors 52 (six in the third embodiment) are provided. The plurality of second capacitors 52 are arranged spaced apart from one another in the X direction. Each second capacitor 52 is arranged to straddle the second surface electrode 192D and the first surface electrode 191B in the Y direction. Each second capacitor 52 is mounted on the second surface electrode 192D and the first surface electrode 191B. More specifically, each second capacitor 52 is individually bonded to the second surface electrode 192D and the first surface electrode 191B by a conductive bonding material SD. The first electrode 52A of each second capacitor 52 is bonded to the second surface electrode 192D. The second electrode 52B of each second capacitor 52 is bonded to the first surface electrode 191B. As a result, the first electrode 52A is electrically connected to the second surface electrode 192D, and the second electrode 52B is electrically connected to the first surface electrode 191B.

[0361] The second capacitors 52 are arranged on the opposite side of the second switching element 181 from the semiconductor light emitting element 30 in the Y direction. In other words, the second switching element 181 is arranged between the semiconductor light emitting element 30 and the second capacitors 52 in the Y direction. When viewed from the Y direction, the second capacitors 52 are arranged in positions that overlap the second switching element 181.

[0362] Because the multiple second surface electrodes 192B are electrically connected to the second surface electrode 192D, the first electrode 52A of each second capacitor 52 is electrically connected to the multiple drain electrodes 181D of the second switching element 181. The multiple source electrodes 181S of the second switching element 181 are electrically connected to the multiple second element surface electrodes 34B via the third surface electrode 193B and the multiple wires W5. Because the second element surface electrode 34B constitutes the second anode electrode of the semiconductor light emitting element 30, it can be said that the second anode electrode is electrically connected to the source electrode 181S of the second switching element 181.

[0363] The semiconductor light emitting device 10 further includes a first protection diode 101 and a second protection diode 102. The first protection diode 101 is a diode that protects the first light emitting portion 33A of the semiconductor light emitting element 30. The first protection diode 101 is disposed closer to the first substrate side surface 23 in the X direction than the semiconductor light emitting element 30, the first switching element 171, and the plurality of first capacitors 42. The first protection diode 101 is disposed on the opposite side of the semiconductor light emitting element 30 in the Y direction relative to the first switching element 171. The first protection diode 101 is disposed in a position overlapping with the first capacitor 42 when viewed from the X direction. The first protection diode 101 is disposed so as to straddle the third surface electrode 193A and the first surface electrode 191B in the Y direction. The first protection diode 101 is mounted on the third surface electrode 193A and the first surface electrode 191B. More specifically, the first protection diode 101 is individually bonded to the third surface electrode 193A and the first surface electrode 191B by a conductive bonding material SD.

[0364] The first protection diode 101 is arranged such that the first anode electrode 101A and the first cathode electrode 101B are at the same position in the X direction and spaced apart from each other in the Y direction. The first protection diode 101 is connected in anti-parallel to the first light-emitting portion 33A. More specifically, the first anode electrode 101A is bonded to the first surface electrode 191B by a conductive bonding material SD. The first anode electrode 101A is disposed on the first surface electrode 191B. This electrically connects the first anode electrode 101A to the back surface electrode 35 of the semiconductor light-emitting element 30 via the first surface electrode 191B and the first surface electrode 191A. The first cathode electrode 101B is bonded to the third surface electrode 193A by a conductive bonding material SD. As a result, the first cathode electrode 101B is electrically connected to the plurality of first element surface electrodes 34A corresponding to the first light emitting portions 33A of the semiconductor light emitting element 30 via the third surface electrode 193A and the wires W5.

[0365] The second protection diode 102 is a diode that protects the second light-emitting portion 33B of the semiconductor light-emitting element 30. The second protection diode 102 is disposed closer to the second substrate side surface 24 in the X direction than the semiconductor light-emitting element 30, the second switching element 181, and the plurality of second capacitors 52. The second protection diode 102 is disposed on the opposite side of the semiconductor light-emitting element 30 from the second switching element 181 in the Y direction. The second protection diode 102 is disposed in a position overlapping with the second capacitor 52 when viewed from the X direction. The second protection diode 102 is disposed so as to straddle the third surface electrode 193B and the first surface electrode 191B in the Y direction. The second protection diode 102 is mounted on the third surface electrode 193B and the first surface electrode 191B. The mounting manner of the second protection diode 102 is the same as that of the first protection diode 101.

[0366] The second protection diode 102 is connected in anti-parallel to the second light-emitting portion 33B. More specifically, the second anode electrode 102A of the second protection diode 102 is joined to the first surface electrode 191B by a conductive bonding material SD. This electrically connects the second anode electrode 102A to the element back surface electrode 35 of the semiconductor light-emitting element 30 via the first surface electrode 191B and the first surface electrode 191A. The second cathode electrode 102B is joined to the third surface electrode 193B by a conductive bonding material SD. This electrically connects the second cathode electrode 102B to a plurality of second element surface electrodes 34B corresponding to the second light-emitting portion 33B of the semiconductor light-emitting element 30 via the third surface electrode 193B and the wire W5.

[0367] [Effects] According to the semiconductor light emitting device 10 of the third embodiment, in addition to the effects (1-1) to (1-12), (1-16), (1-17), and (1-19) of the first embodiment, the following effects can be obtained.

[0368] (3-1) The first switching element 171 includes a source electrode 171S, a drain electrode 171D, and a gate electrode 171G formed on the second element back surface 171B. The second switching element 181 includes a source electrode 181S, a drain electrode 181D, and a gate electrode 181G formed on the second element back surface 181B. The source electrode 171S, the drain electrode 171D, and the gate electrode 181G of the first switching element 171 are mounted on a plurality of front surface electrodes 28A. The source electrode 181S, the drain electrode 181D, and the gate electrode 181G of the second switching element 181 are mounted on a plurality of front surface electrodes 28A.

[0369] According to this configuration, since wires are not used to electrically connect the source electrode 171S, the drain electrode 171D, and the gate electrode 171G of the first switching element 171 to the plurality of surface electrodes 28A, it is possible to reduce the inductance of the loop-shaped first current path formed by the semiconductor light-emitting element 30, the first switching element 171, and the first capacitor 42. Furthermore, since wires are not used to electrically connect the source electrode 181S, the drain electrode 181D, and the gate electrode 181G of the second switching element 181 to the plurality of surface electrodes 28A, it is possible to reduce the inductance of the loop-shaped second current path formed by the semiconductor light-emitting element 30, the second switching element 181, and the second capacitor 52.

[0370] (3-2) The first switching element 171 is formed in a rectangular shape with its longitudinal direction in the X direction and its lateral direction in the Y direction in plan view. The second switching element 181 is formed in a rectangular shape with its longitudinal direction in the X direction and its lateral direction in the Y direction in plan view.

[0371] According to this configuration, the direction (X direction) orthogonal to the arrangement direction (Y direction) of the semiconductor light emitting element 30, the first switching element 171, and the first capacitor 42 is the longitudinal direction of the first switching element 171. Therefore, the distance in the Y direction between the semiconductor light emitting element 30 and the first capacitor 42 can be shortened compared to a configuration in which the arrangement direction is the longitudinal direction of the first switching element 171. As a result, the loop-shaped first current path formed by the semiconductor light emitting element 30, the first switching element 171, and the first capacitor 42 can be shortened. Furthermore, the direction (X direction) orthogonal to the arrangement direction (Y direction) of the semiconductor light emitting element 30, the second switching element 181, and the second capacitor 52 is the longitudinal direction of the second switching element 181. Therefore, the distance in the Y direction between the semiconductor light emitting element 30 and the second capacitor 52 can be shortened compared to a configuration in which the arrangement direction is the longitudinal direction of the second switching element 181. As a result, the loop-shaped second current path formed by the semiconductor light emitting element 30, the second switching element 181, and the second capacitor 52 can be shortened.

[0372] (3-3) The semiconductor light emitting device 10 is provided on the substrate 20 and includes first vias 211A, 211B, 211C, second vias 212A, 212B, third vias 213A, 213B, and fourth vias 214A, 214B as a plurality of vias that connect the plurality of back electrodes 28B and the plurality of front electrodes 28A. A first current path between the first light emitting unit 33A of the semiconductor light emitting element 30 and the first drive circuit 40 is formed by the first front electrodes 191A, 191B, the second front electrode 192A, the third front electrode 193A, the fourth front electrode 194A, the first back electrode 201, the second back electrode 202A, the first vias 211A, 211B, and the second via 212A. The second current path between the second light-emitting portion 33B of the semiconductor light-emitting element 30 and the second driving circuit 50 is composed of the first surface electrodes 191A, 191B, the second surface electrode 192B, the third surface electrode 193B, the fourth surface electrode 194B, the first back surface electrode 201, the second back surface electrode 202B, the first vias 211A, 211B, and the second via 212B.

[0373] According to this configuration, a portion of the loop of the first current path, through which current flows in the order of the first electrode 42A of the first capacitor 42, the drain electrode 171D and source electrode 171S of the first switching element 171, the first front surface electrode 34A and back surface electrode 35 of the semiconductor light-emitting element 30, and the second electrode 42B of the first capacitor 42, is formed by the first back surface electrode 201. This reduces the loop area of ​​the first current path, thereby reducing the inductance of the first current path. Furthermore, a portion of the loop of the second current path, through which current flows in the order of the first electrode 52A of the second capacitor 52, the drain electrode 181D and source electrode 181S of the second switching element 181, the second front surface electrode 34B and back surface electrode 35 of the semiconductor light-emitting element 30, and the second electrode 52B of the second capacitor 52, is formed by the first back surface electrode 201. This reduces the loop area of ​​the second current path, thereby reducing the inductance of the second current path.

[0374] (3-4) The substrate 20 includes one base material 27. A plurality of front electrodes 28A are formed on the base material surface (substrate front surface 21) of the base material 27, and a plurality of back surface electrodes 28B are formed on the base material back surface (substrate back surface 22) of the base material 27.

[0375] With this configuration, the distance in the Z direction between the plurality of front electrodes 28A and the plurality of back electrodes 28B is shorter than in a configuration in which the substrate 20 includes a plurality of base materials 27. Therefore, heat from the semiconductor light emitting element 30 is more likely to transfer to the outside of the semiconductor light emitting device 10 via the front electrode 28A and the back electrode 28B.

[0376] (3-5) Horizontal transistors of the same configuration are used for the first switching element 171 and the second switching element 181. With this configuration, only one type of switching element is used in the semiconductor light emitting device 10, which reduces the manufacturing cost of the semiconductor light emitting device 10 compared to when two types of switching elements are used.

[0377] 16 to 19, a semiconductor light emitting device 10 according to a fourth embodiment will be described. The semiconductor light emitting device 10 according to the fourth embodiment differs from the semiconductor light emitting device 10 according to the third embodiment in the number of light emitting units that are individually controlled. Below, differences from the third embodiment will be described in detail, and components common to the third embodiment will be denoted by the same reference numerals, and their description may be omitted.

[0378] FIG. 16 shows a schematic planar structure of a semiconductor light-emitting device 10 of the fourth embodiment. FIG. 17 shows a schematic backside structure of the semiconductor light-emitting device 10 of FIG. 16. FIG. 18 shows a schematic planar structure of the semiconductor light-emitting device 10 of FIG. 16, enlarging the region between the imaginary center line VC and the first substrate side surface 23. FIG. 19 shows a schematic planar structure of the semiconductor light-emitting device 10 of FIG. 16, enlarging the region between the imaginary center line VC and the second substrate side surface 24. The rectangular frames drawn with two-dot chain lines in FIGS. 16, 18, and 19 indicate openings in the front surface resist 29A (see FIG. 3). The rectangular frames drawn with two-dot chain lines in FIG. 17 indicate openings in the back surface resist 29B (see FIG. 3).

[0379] 16 , the semiconductor light emitting element 30 includes first to fourth light emitting portions 33A to 33D, each including two light emitting portions 33 out of eight light emitting portions 33, and first to fourth element surface electrodes 34A to 34D provided corresponding to the first to fourth light emitting portions 33A. The first element surface electrode 34A is provided on the first light emitting portion 33A, the second element surface electrode 34B is provided on the second light emitting portion 33B, the third element surface electrode 34C is provided on the third light emitting portion 33C, and the fourth element surface electrode 34D is provided on the fourth light emitting portion 33D. The number of each of the first to fourth element surface electrodes 34A to 34D is set according to the number of the first to fourth light emitting portions 33A to 33D. In the fourth embodiment, since the number of each of the first to fourth light emitting portions 33A to 33D is two, the number of each of the first to fourth element surface electrodes 34A to 34D is two. The first element surface electrode 34A is an example of a "first anode electrode," the second element surface electrode 34B is an example of a "second anode electrode," the third element surface electrode 34C is an example of a "third anode electrode," and the fourth element surface electrode 34D is an example of a "fourth anode electrode."

[0380] The semiconductor light emitting device 10 includes a configuration for individually controlling the driving of the first to fourth light emitting units 33A to 33D. As a result, the semiconductor light emitting device 10 includes a first drive circuit 40 that drives the first light emitting unit 33A, a second drive circuit 50 that drives the second light emitting unit 33B, a third drive circuit 110 that drives the third light emitting unit 33C, and a fourth drive circuit 120 that drives the fourth light emitting unit 33D.

[0381] The first drive circuit 40 includes a first switching element 171 and a first capacitor 42, as in the third embodiment. The second drive circuit 50 includes a second switching element 181 and a second capacitor 52, as in the third embodiment. However, the first switching element 171 and the second switching element 181 are horizontal transistors, as in the third embodiment, but their configurations are different from those in the third embodiment. The configurations of the first switching element 171 and the second switching element 181 will be described later.

[0382] The third drive circuit 110 includes a third switching element 221 that controls the driving of the third light-emitting unit 33 C, and a third capacitor 112 that supplies current to the third light-emitting unit 33 C. The third switching element 221 and the third capacitor 112 are arranged apart from the semiconductor light-emitting element 30.

[0383] The fourth drive circuit 120 includes a fourth switching element 222 that controls the driving of the fourth light-emitting unit 33D and a fourth capacitor 122 that supplies current to the fourth light-emitting unit 33D. The fourth switching element 222 and the fourth capacitor 122 are arranged apart from the semiconductor light-emitting element 30.

[0384] Due to these changes in the configuration of the drive circuit, the configuration of the substrate 20 differs from that of the third embodiment. The configuration of the substrate 20 of the fourth embodiment will be described below. As shown in Figures 16, 18, and 19, the substrate 20 includes first surface electrodes 231A, 231B, second surface electrodes 232A to 232D, third surface electrodes 233A to 233H, and fourth surface electrodes 234A to 234D as surface electrodes 28A formed on the substrate surface 21. The first surface electrodes 231A, 231B, second surface electrodes 232A to 232D, third surface electrodes 233A to 233H, and fourth surface electrodes 234A to 234D are arranged spaced apart from one another.

[0385] The first surface electrode 231A is a surface electrode on which the semiconductor light emitting element 30 is mounted. The first surface electrode 231A is disposed near the third substrate side surface 25 of the substrate surface 21 and at the center of the substrate surface 21 in the X direction in a plan view. The first surface electrode 231A is formed in a rectangular shape with the X direction as the longitudinal direction and the Y direction as the lateral direction in a plan view. The first surface electrode 231A has an axisymmetric shape with respect to the imaginary center line VC. The dimension of the first surface electrode 231A in the X direction is greater than ¼ and less than ⅓ of the dimension of the substrate surface 21 in the X direction.

[0386] The first surface electrode 231B is a surface electrode constituting a ground wiring electrically connected to a ground terminal electrically connected to the negative pole of the DC power supply 801 (see FIG. 5 ). The first surface electrode 231B is formed in a generally U-shape on the outer periphery of the substrate surface 21. The first surface electrode 231B includes a first wiring portion 231BA formed along the first substrate side surface 23, a second wiring portion 231BB formed along the second substrate side surface 24, and a third wiring portion 231BC formed along the fourth substrate side surface 26. In one example, the first wiring portion 231BA, the second wiring portion 231BB, and the third wiring portion 231BC are integrated. The first surface electrode 231B has a shape that is line-symmetrical with respect to the imaginary center line VC. The dashed-dotted line drawn on the first surface electrode 231B in FIG. 16 is a boundary line that separates the first wiring portion 231BA, the second wiring portion 231BB, and the third wiring portion 231BC.

[0387] In a plan view, the first surface electrode 231B is formed to surround the first surface electrode 231A, the second surface electrodes 232A to 232D, the third surface electrodes 233A to 233H, and the fourth surface electrodes 234A to 234D. The area of ​​the first surface electrode 231B is larger than the area of ​​each of the first surface electrode 231A, the second surface electrodes 232A to 232D, the third surface electrodes 233A to 233H, and the fourth surface electrodes 234A to 234D.

[0388] The first wiring portion 231BA includes a wide portion 231CA and a narrow portion 231CB. The wide portion 231CA constitutes a portion of the first wiring portion 231BA that is continuous with the third wiring portion 231BC. The narrow portion 231CB is provided on the opposite side of the wide portion 231CA from the third wiring portion 231BC. The wide portion 231CA and the narrow portion 231CB form a recessed portion 231CC. The length of the narrow portion 231CB in the Y direction is longer than the length of the wide portion 231CA in the Y direction.

[0389] The second wiring portion 231BB includes a wide portion 231DA and a narrow portion 231DB. The second wiring portion 231BB is disposed in line symmetry with the first wiring portion 231BA about the imaginary center line VC. The second wiring portion 231BB has a shape in line symmetry with the first wiring portion 231BA about the imaginary center line VC. Therefore, the wide portion 231DA and the narrow portion 231DB form a recessed portion 231DC.

[0390] The third wiring portion 231BC includes a first recess 231EA and a second recess 231EB. The first recess 231EA and the second recess 231EB are formed in a rectangular recessed shape such that the third wiring portion 231BC is recessed toward the fourth substrate side surface 26. It can be said that both the first recess 231EA and the second recess 231EB are open toward the third substrate side surface 25. The second recess 231EB is formed within the first recess 231EA. More specifically, the second recess 231EB is recessed from the bottom surface of the first recess 231EA toward the fourth substrate side surface 26. The Y-direction dimension of the first recess 231EA, which is the depth dimension of the first recess 231EA, is greater than the Y-direction dimension of the second recess 231EB, which is the depth dimension of the second recess 231EB. The dimension of the second recess 231EB in the X direction is larger than the dimension of the first surface electrode 231A in the X direction. The first recess 231EA and the second recess 231EB are each symmetrical with respect to the imaginary center line VC.

[0391] The second surface electrodes 232A, 232B, the third surface electrodes 233A, 233B, 233E, 233F, and the fourth surface electrodes 234A, 234B are arranged between the first surface electrode 231A and the third wiring portion 231BC of the first surface electrode 231B in the Y direction.

[0392] The second surface electrode 232A, the third surface electrodes 233A and 233E, and the fourth surface electrode 234A are electrodes electrically connected to the first drive circuit 40. The second surface electrode 232B, the third surface electrodes 233B and 233F, and the fourth surface electrode 234B are electrodes electrically connected to the second drive circuit 50.

[0393] The third surface electrode 233A is an electrode electrically connected to the drain electrode 171D of the first switching element 171. The third surface electrode 233A is disposed closer to the imaginary center line VC in the X direction between the imaginary center line VC and the first substrate side surface 23. The third surface electrode 233A is formed in an elliptical shape with the Y direction as the longitudinal direction and the X direction as the lateral direction in a plan view.

[0394] The second surface electrode 232A is an electrode electrically connected to the source electrode 171S of the first switching element 171. The second surface electrode 232A is formed to surround the third surface electrode 233A in a plan view. The second surface electrode 232A is arranged between the first surface electrode 231A and the third wiring portion 231BC of the first surface electrode 231B in the Y direction. Of both ends of the second surface electrode 232A in the Y direction, the end closer to the third substrate side surface 25 is arranged adjacent to the first surface electrode 231A in the Y direction. The end closer to the fourth substrate side surface 26 of the second surface electrode 232A is arranged adjacent to the third surface electrode 233E and the third wiring portion 231BC in the Y direction. The end closer to the fourth substrate side surface 26 of the second surface electrode 232A is arranged within the first recess 231EA of the third wiring portion 231BC. The end of the second surface electrode 232A closer to the fourth substrate side surface 26 is formed so as to surround a part of the third surface electrode 233E.

[0395] The third surface electrode 233E is an electrode electrically connected to the third surface electrode 233A. The third surface electrode 233E is arranged closer to the third wiring portion 231BC than the third surface electrode 233A in the Y direction. A portion of the third surface electrode 233E is arranged within the second recess 231EB of the third wiring portion 231BC. The third surface electrode 233E is arranged at a position adjacent to the imaginary center line VC in the X direction. The third surface electrode 233E is formed in a rectangular shape with the X direction as the longitudinal direction and the Y direction as the lateral direction in a plan view.

[0396] The fourth surface electrode 234A is an electrode electrically connected to the gate electrode 171G of the first switching element 171. The fourth surface electrode 234A is disposed between the first surface electrode 231A and the third surface electrode 233E in the Y direction, closer to the third surface electrode 233E. The fourth surface electrode 234A has a rectangular shape with its longitudinal direction in the X direction and its lateral direction in the Y direction in a plan view. The fourth surface electrode 234A is surrounded by the second surface electrode 232A and the third surface electrode 233A.

[0397] The third surface electrode 233B is an electrode electrically connected to the drain electrode 181D of the second switching element 181. In one example, the third surface electrode 233B is in a line-symmetric relationship with the third surface electrode 233A with respect to the imaginary center line VC.

[0398] The second surface electrode 232B is an electrode electrically connected to the source electrode 181S of the second switching element 181. The second surface electrode 232B is disposed closer to the second substrate side surface 24 than the imaginary center line VC. The second surface electrode 232B has a shape that is different from the shape that is linearly symmetrical with respect to the second surface electrode 232A about the imaginary center line VC. The second surface electrode 232B is formed to surround the third surface electrode 233B. Of both ends of the second surface electrode 232B in the Y direction, the end closer to the third substrate side surface 25 is disposed adjacent to the first surface electrode 231A in the Y direction. The end closer to the fourth substrate side surface 26 of the second surface electrode 232B is disposed adjacent to the third surface electrode 233F and the third wiring portion 231BC in the Y direction. The end closer to the fourth substrate side surface 26 of the second surface electrode 232B is disposed within the first recess 231EA of the third wiring portion 231BC. The end of the second surface electrode 232B closer to the fourth substrate side surface 26 is formed so as to surround a part of the third surface electrode 233F.

[0399] The third surface electrode 233F is an electrode electrically connected to the third surface electrode 233B. In one example, the third surface electrode 233F is in a line-symmetric relationship with the third surface electrode 233E with respect to the imaginary center line VC.

[0400] The fourth surface electrode 234B is an electrode electrically connected to the gate electrode 181G of the second switching element 181. The fourth surface electrode 234B is disposed between the first surface electrode 231A and the third surface electrode 233F in the Y direction, closer to the first surface electrode 231A. The fourth surface electrode 234B has a rectangular shape with its longitudinal direction in the X direction and its lateral direction in the Y direction in a plan view. The fourth surface electrode 234B is surrounded by the second surface electrode 232B and the third surface electrode 233B.

[0401] The second surface electrode 232C, the third surface electrodes 233C and 233G, and the fourth surface electrode 234C are arranged between the first surface electrode 231A and the first wiring portion 231BA of the first surface electrode 231B in the X direction. The second surface electrode 232C, the third surface electrodes 233C and 233G, and the fourth surface electrode 234C are electrodes electrically connected to the third drive circuit 110. The second surface electrode 232C is an electrode electrically connected to a source electrode 221S (described later) of the third switching element 221 of the third drive circuit 110. The third surface electrode 233C is an electrode electrically connected to a drain electrode 221D (described later) of the third switching element 221. The third surface electrode 233G is an electrode electrically connected to the third surface electrode 233C. The fourth surface electrode 234C is an electrode electrically connected to a gate electrode 221G (described later) of the third switching element 221.

[0402] The second surface electrode 232C, the third surface electrodes 233C and 233G, and the fourth surface electrode 234C are the same in shape and size as the second surface electrode 232B, the third surface electrodes 233B and 233F, and the fourth surface electrode 234B. The second surface electrode 232C, the third surface electrodes 233C and 233G, and the fourth surface electrode 234C are arranged in a manner rotated 90 degrees counterclockwise from the second surface electrode 232B, the third surface electrodes 233B and 233F, and the fourth surface electrode 234B.

[0403] A portion of the third surface electrode 233G is disposed within the recessed portion 231CC of the first wiring portion 231BA. A portion of the second surface electrode 232C is formed so as to surround a portion of the third surface electrode 233G. The third surface electrode 233C includes a portion that faces the wide portion 231CA of the first wiring portion 231BA in the X direction. The third surface electrode 233C includes a portion that is adjacent in the X direction to the end portion of the first surface electrode 231A that is closer to the first substrate side surface 23, of both end portions in the X direction.

[0404] The second surface electrode 232D, the third surface electrodes 233D and 233H, and the fourth surface electrode 234D are arranged between the first surface electrode 231A and the second wiring portion 231BB of the first surface electrode 231B in the X direction. The second surface electrode 232D, the third surface electrodes 233D and 233H, and the fourth surface electrode 234D are electrodes electrically connected to the fourth drive circuit 120. The second surface electrode 232D is an electrode electrically connected to a source electrode 222S (described later) of the fourth switching element 222 of the fourth drive circuit 120. The third surface electrode 233D is an electrode electrically connected to a drain electrode 222D (described later) of the fourth switching element 222. The third surface electrode 233H is an electrode electrically connected to the third surface electrode 233D. The fourth surface electrode 234D is an electrode electrically connected to a gate electrode 222G (described later) of the fourth switching element 222.

[0405] The second surface electrode 232D, the third surface electrodes 233D and 233H, and the fourth surface electrode 234D are the same in shape and size as the second surface electrode 232A, the third surface electrodes 233A and 233E, and the fourth surface electrode 234A. The second surface electrode 232D, the third surface electrodes 233D and 233H, and the fourth surface electrode 234D are arranged in a manner rotated 90° clockwise from the second surface electrode 232A, the third surface electrodes 233A and 233E, and the fourth surface electrode 234A.

[0406] A portion of the third surface electrode 233H is disposed within the recess 231DC of the second wiring portion 231BB. A portion of the second surface electrode 232D is formed so as to surround a portion of the third surface electrode 233H. The third surface electrode 233D includes a portion that faces the wide portion 231DA of the second wiring portion 231BB in the X direction. The third surface electrode 233D includes a portion that is adjacent in the X direction to the end of the first surface electrode 231A that is closer to the second substrate side surface 24.

[0407] As shown in FIG. 17, the back surface electrode 28B includes first back surface electrodes 241A to 241C, second back surface electrodes 242A to 242D, third b...

Claims

1. A semiconductor light emitting device comprising: a substrate having a substrate surface and a substrate back surface facing opposite to the substrate surface; a plurality of surface electrodes formed on the substrate surface; a plurality of back surface electrodes formed on the substrate back surface and configured to mount the semiconductor light emitting device; a semiconductor light emitting element including a first light emitting portion and a second light emitting portion, a first element surface electrode electrically connected to the first light emitting portion, a second element surface electrode electrically connected to the second light emitting portion, and an element back surface electrode electrically connected to both the first light emitting portion and the second light emitting portion; a first drive circuit electrically connected to the first element surface electrode and driving the first light emitting portion; and a second drive circuit electrically connected to the second element surface electrode and driving the second light emitting portion, wherein the element back electrode of the semiconductor light emitting element, the first drive circuit, and the second drive circuit are mounted on the plurality of surface electrodes.

2. The semiconductor light-emitting device of claim 1, wherein the first drive circuit includes a first switching element that controls the drive of the first light-emitting unit and a first capacitor that supplies current to the first light-emitting unit, and the second drive circuit includes a second switching element that controls the drive of the second light-emitting unit and a second capacitor that supplies current to the second light-emitting unit.

3. The semiconductor light emitting device according to claim 2, wherein both the first switching element and the second switching element include a source electrode and a gate electrode formed on a front surface of the element, and a drain electrode formed on a back surface of the element, and the drain electrode is mounted on a plurality of the front surface electrodes.

4. The semiconductor light emitting device according to claim 2, wherein both the first switching element and the second switching element include a source electrode, a drain electrode, and a gate electrode formed on a rear surface of the element, and the source electrode, the drain electrode, and the gate electrode are mounted on a plurality of the front electrodes.

5. The semiconductor light-emitting device of claim 2, wherein the first switching element and the second switching element include a drain electrode, a source electrode, and a gate electrode, the first capacitor and the second capacitor include a first electrode and a second electrode, the first element surface electrode constitutes a first anode electrode, the second element surface electrode constitutes a second anode electrode, the element back surface electrode constitutes a cathode electrode, the source electrode of the first switching element is electrically connected to the first anode electrode, the drain electrode of the first switching element is electrically connected to the first electrode of the first capacitor, the source electrode of the second switching element is electrically connected to the second anode electrode, and the cathode electrode is electrically connected to the second electrode of the first capacitor and the second electrode of the second capacitor.

6. The semiconductor light-emitting device described in claim 5, wherein, when viewed from the thickness direction of the substrate, the semiconductor light-emitting element and the first capacitor are arranged at a distance from each other in a first direction, when viewed from the thickness direction, the first switching element is arranged between the semiconductor light-emitting element and the first capacitor in the first direction, when viewed from the thickness direction, the semiconductor light-emitting element and the second capacitor are arranged at a distance from each other in the first direction, and when viewed from the thickness direction, the second switching element is arranged between the semiconductor light-emitting element and the second capacitor in the first direction.

7. The semiconductor light emitting device according to claim 6, wherein the distance between the semiconductor light emitting element and the first switching element in the first direction is equal to the distance between the semiconductor light emitting element and the second switching element in the first direction.

8. The semiconductor light emitting device according to claim 6, wherein a plurality of the first capacitors and a plurality of the second capacitors are provided, the plurality of first capacitors are connected in parallel to each other, and the plurality of the second capacitors are connected in parallel to each other.

9. The semiconductor light emitting device according to claim 8, wherein a direction perpendicular to the first direction when viewed from the thickness direction is defined as a second direction, the first capacitors are arranged at a distance from each other in the second direction, and the second capacitors are arranged at a distance from each other in the second direction.

10. The semiconductor light emitting device according to claim 1, further comprising: a first protection diode connected in anti-parallel to the first light emitting section; and a second protection diode connected in anti-parallel to the second light emitting section.

11. the first drive circuit includes a first switching element that controls driving of the first light-emitting unit and a first capacitor that supplies a current to the first light-emitting unit; the second drive circuit includes a second switching element that controls driving of the second light-emitting unit and a second capacitor that supplies a current to the second light-emitting unit; when viewed from a thickness direction of the substrate, the semiconductor light-emitting element and the first capacitor are arranged spaced apart from each other in a first direction; when viewed from the thickness direction, the first switching element is arranged between the semiconductor light-emitting element and the first capacitor in the first direction; when viewed from the thickness direction, the semiconductor light-emitting element and the second capacitor are arranged spaced apart from each other in the first direction; when viewed from the thickness direction, the second switching element is arranged between the semiconductor light-emitting element and the second capacitor in the first direction; a direction perpendicular to the first direction when viewed from the thickness direction is a second direction; the first protection diode is arranged on the opposite side of the semiconductor light-emitting element with respect to the first switching element in the first direction, and is arranged spaced apart from the first capacitor in the second direction; The semiconductor light emitting device according to claim 10 , wherein the second protection diode is disposed on an opposite side of the second switching element from the semiconductor light emitting element in the first direction, and is disposed apart from the second capacitor in the second direction.

12. The semiconductor light-emitting device of claim 1, wherein the semiconductor light-emitting element includes a third light-emitting portion and a fourth light-emitting portion, a third element surface electrode electrically connected to the third light-emitting portion, and a fourth element surface electrode electrically connected to the fourth light-emitting portion, and further comprises a third drive circuit electrically connected to the third element surface electrode and driving the third light-emitting portion, and a fourth drive circuit electrically connected to the fourth element surface electrode and driving the fourth light-emitting portion, and the third drive circuit and the fourth drive circuit are mounted on a plurality of the surface electrodes.

13. The semiconductor light-emitting device described in claim 12, wherein, when viewed from the thickness direction of the substrate, the first drive circuit and the second drive circuit are arranged at a distance in a first direction from the semiconductor light-emitting element, and a direction perpendicular to the first direction when viewed from the thickness direction is defined as a second direction, and the third drive circuit and the fourth drive circuit are arranged in a distributed manner on both sides of the semiconductor light-emitting element in the second direction.

14. The semiconductor light-emitting device of claim 12, wherein the third drive circuit includes a third switching element that controls the drive of the third light-emitting unit and a third capacitor that supplies current to the third light-emitting unit, and the fourth drive circuit includes a fourth switching element that controls the drive of the fourth light-emitting unit and a fourth capacitor that supplies current to the fourth light-emitting unit.

15. The semiconductor light-emitting device of claim 14, wherein, when viewed from the thickness direction of the substrate, the semiconductor light-emitting element and the third capacitor are arranged at a distance from each other in the second direction; when viewed from the thickness direction, the third switching element is arranged between the semiconductor light-emitting element and the third capacitor in the second direction; when viewed from the thickness direction, the semiconductor light-emitting element and the fourth capacitor are arranged at a distance from each other in the second direction; and when viewed from the thickness direction, the fourth switching element is arranged between the semiconductor light-emitting element and the fourth capacitor in the second direction.

16. The semiconductor light emitting device according to claim 15, wherein the distance between the semiconductor light emitting element and the third switching element in the second direction is equal to the distance between the semiconductor light emitting element and the fourth switching element in the second direction.

17. The semiconductor light-emitting device of claim 1, further comprising a plurality of vias provided on the substrate and connecting a plurality of the back electrodes and a plurality of the front electrodes, a first current path between the first light-emitting portion of the semiconductor light-emitting element and the first drive circuit being formed by the front electrodes, the back electrode, and the vias, and a second current path between the second light-emitting portion of the semiconductor light-emitting element and the second drive circuit being formed by the front electrodes, the back electrode, and the vias.

18. The semiconductor light-emitting device of claim 1, comprising: a plurality of intermediate electrodes provided between a plurality of the front electrodes and a plurality of the back electrodes in the thickness direction of the substrate; and a plurality of vias provided on the substrate, connecting the plurality of the back electrodes, the plurality of the front electrodes, and the plurality of the intermediate electrodes; a first current path between the first light-emitting portion of the semiconductor light-emitting element and the first drive circuit being formed by the front electrodes, the intermediate electrodes, and the vias; and a second current path between the second light-emitting portion of the semiconductor light-emitting element and the second drive circuit being formed by the front electrodes, the intermediate electrodes, and the vias.

19. The semiconductor device further includes a first protection diode, a second protection diode, a first reverse current prevention diode, a second reverse current prevention diode, and a light emission switching element, wherein the light emission switching element includes a drain electrode and a source electrode, the first drive circuit includes a first capacitor, and the second drive circuit includes a second capacitor, each of the first capacitor and the second capacitor includes a first electrode and a second electrode, the first element surface electrode constitutes a first anode electrode, the second element surface electrode constitutes a second anode electrode, and the element back electrode constitutes a cathode electrode, an anode of the first reverse current prevention diode is electrically connected to the first electrode of the first capacitor, a cathode of the first reverse current prevention diode is electrically connected to the first anode electrode and the cathode of the first protection diode, and an anode of the second reverse current prevention diode is electrically connected to the first electrode of the second capacitor, 2. The semiconductor light-emitting device according to claim 1, wherein a cathode of the second reverse current prevention diode is electrically connected to the second anode electrode and the cathode of the second protection diode, and an anode of the first protection diode and an anode of the second protection diode are electrically connected to the cathode electrode and the drain electrode of the light-emitting switching element.

20. The semiconductor light emitting device according to claim 19, wherein the light emitting switching element includes a first light emitting switching element and a second light emitting switching element connected in parallel to each other.

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