Light-emitting semiconductor device

Abstract

This light-emitting semiconductor device includes: a plurality of front-surface electrodes formed on the front surface of a substrate; a plurality of back-surface electrodes formed on the back surface of the substrate; a first light-emitting semiconductor element; a second light-emitting semiconductor element; a first drive circuit for driving the first light-emitting semiconductor element; and a second drive circuit for driving the second light-emitting semiconductor element. The first light-emitting semiconductor element and the second light-emitting semiconductor element each include an element front-surface electrode and an element back-surface electrode. Mounted on the plurality of front-surface electrodes are: the element back-surface electrode of the first light-emitting semiconductor element; the element back-surface electrode of the second light-emitting semiconductor element; the first drive circuit; and the second drive circuit.

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 semiconductor light-emitting device according to one aspect of the present disclosure is 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 electrodes formed on the substrate back surface, electrically connected to the plurality of surface electrodes and constituting a mounting surface of the semiconductor light-emitting device; a first semiconductor light-emitting element and a second semiconductor light-emitting element each including an element surface electrode and an element back electrode; a first drive circuit that drives the first semiconductor light-emitting element; and a second drive circuit that drives the second semiconductor light-emitting element, wherein the element back electrode of the first semiconductor light-emitting element, the element back electrode of the second semiconductor light-emitting element, the first drive circuit, and the second drive circuit 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 plan view of an enlarged portion of the semiconductor light emitting device of FIG. 1. FIG. 3 is a schematic back view of the semiconductor light emitting device of FIG. 1. FIG. 4 is a schematic cross-sectional view of the semiconductor light emitting device taken along line F4-F4 in FIG. 1. FIG. 5 is a schematic plan view of a front-side intermediate electrode of the semiconductor light emitting device of FIG. 1. FIG. 6 is a schematic circuit diagram of a light emitting system including the semiconductor light emitting device of the first embodiment. FIG. 7 is a schematic cross-sectional view of the semiconductor light emitting device of FIG. 4 mounted on a circuit board. FIG. 8 is a schematic cross-sectional view for explaining a current path flowing within the semiconductor light emitting device. FIG. 9 is a schematic plan view of a semiconductor light emitting device of a second embodiment. FIG. 10 is a schematic plan view of an enlarged portion of the semiconductor light emitting device of FIG. 9. FIG. 11 is a schematic back view of the semiconductor light emitting device of FIG. 9. FIG. 12 is a schematic plan view of a front-side intermediate electrode of the semiconductor light emitting device of FIG. 9. FIG. 13 is a schematic circuit diagram of a light emitting system including the semiconductor light emitting device of the second embodiment. FIG. 14 is a schematic plan view of a semiconductor light emitting device of a third embodiment. 15 is a schematic plan view showing an enlargement of a portion of the semiconductor light emitting device of FIG. 14 . FIG. 16 is a schematic plan view showing an enlargement of another portion of the semiconductor light emitting device of FIG. 14 . FIG. 17 is a schematic back view of the semiconductor light emitting device of FIG. 14 . FIG. 18 is a schematic plan view of a front-side intermediate electrode of the semiconductor light emitting device of FIG. 14 . FIG. 19 is a schematic circuit diagram of a light emitting system including the semiconductor light emitting device of the third embodiment. FIG. 20 is a schematic plan view of a semiconductor light emitting device of the fourth embodiment. FIG. 21 is a schematic plan view showing an enlargement of a portion of the semiconductor light emitting device of FIG. 20 . FIG. 22 is a schematic plan view showing an enlargement of another portion of the semiconductor light emitting device of FIG. 20 . FIG. 23 is a schematic back view of the semiconductor light emitting device of FIG. 20 . FIG. 24 is a schematic plan view of a front-side intermediate electrode of the semiconductor light emitting device of FIG. 20 . FIG. 25 is a schematic plan view of a back-side intermediate electrode of the semiconductor light emitting device of FIG. 20 . FIG. 26 is a schematic circuit diagram of a light emitting system including the semiconductor light emitting device of the fourth embodiment. FIG. 27 is a schematic plan view of a semiconductor light emitting device of the fifth embodiment. Fig. 28 is a schematic plan view enlarging a portion of the semiconductor light emitting device of Fig. 27. Fig. 29 is a schematic plan view enlarging another portion of the semiconductor light emitting device of Fig. 27. Fig. 30 is a schematic back view of the semiconductor light emitting device of Fig. 27. Fig. 31 is a schematic plan view of a front surface side intermediate electrode of the semiconductor light emitting device of Fig. 27.32 is a schematic plan view of the back surface intermediate electrode of the semiconductor light emitting device of FIG.

[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 8. FIG. 1 shows a schematic planar structure of the semiconductor light-emitting device 10. FIG. 2 shows an enlarged schematic planar structure of a half of the semiconductor light-emitting device 10 shown in FIG. 1, the half closer to a first substrate side surface 23 of a substrate 20 (described later). FIG. 3 shows a schematic rear surface structure of the semiconductor light-emitting device 10. FIG. 4 shows a schematic cross-sectional structure of the semiconductor light-emitting device 10 taken along line F4-F4 in FIG. 1. FIG. 5 shows a schematic planar structure of a front-side intermediate electrode 28C (described later) in the semiconductor light-emitting device 10. FIG. 6 shows a schematic circuit configuration of a light-emitting system 800 including the semiconductor light-emitting device 10. FIG. 7 shows a schematic cross-sectional structure of the semiconductor light-emitting device 10 mounted on a circuit board 900. FIG. 8 is an explanatory diagram illustrating the flow of current through the semiconductor light-emitting device 10. Note that hatching lines for some components have been omitted in FIGS. 4, 7, and 8 to facilitate understanding of the drawings. Furthermore, 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 Figure 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, and a first semiconductor light emitting element 30A, a second semiconductor light emitting element 30B, a first drive circuit 40A, and a second drive circuit 40B arranged on the substrate 20. The first semiconductor light emitting element 30A, the second semiconductor light emitting element 30B, the first drive circuit 40A, and the second drive circuit 40B are arranged spaced apart from each other on the substrate 20.

[0011] The substrate 20 is a component that supports the first semiconductor light emitting element 30A, the second semiconductor light emitting element 30B, the first drive circuit 40A, and the second drive circuit 40B. 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 (see FIG. 4 ) 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. 4, the substrate 20 is a multilayer substrate. In the example shown in Fig. 4, the substrate 20 is a four-layer substrate. That is, the substrate 20 includes a plurality of base materials 27 and a plurality of front electrodes 28A, a plurality of back electrodes 28B, a plurality of front-side intermediate electrodes 28C, and a plurality of back-side intermediate electrodes 28D provided on the base materials 27. Each of the front electrodes 28A, each back electrode 28B, each front-side intermediate electrode 28C, and each back-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. 4 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 substrates 27A, 27B, and 27C. For convenience, FIG. 4 illustrates the respective substrates 27A, 27B, and 27C and the portions covering the ends of the front-side intermediate electrode 28C and the back-side intermediate electrode 28D by solid lines. The interfaces between the respective substrates 27A, 27B, and 27C may not be clearly defined. The detailed configurations of the front-side electrode 28A, the back-side electrode 28B, and the front-side intermediate electrode 28C are described below. The configuration of the back-side intermediate electrode 28D is the same as that of the front-side intermediate electrode 28C, and therefore a detailed description thereof will be omitted.

[0015] 1, a plurality of surface electrodes 28A are formed on the substrate surface 21. The plurality of surface electrodes 28A include first surface electrodes 61A, 61B, second surface electrodes 62A, 62B, third surface electrodes 63A, 63B, fourth surface electrodes 64A, 64B, and fifth surface electrodes 65A, 65B that are arranged spaced apart from one another.

[0016] 1 , the first surface electrode 61A, the second surface electrode 62A, the third surface electrode 63A, the fourth surface electrode 64A, and the fifth surface electrode 65A are arranged closer to the first substrate side surface 23 than an imaginary center line VC extending along the Y direction at the center of the substrate surface 21 in the X direction. The first surface electrode 61B, the second surface electrode 62B, the third surface electrode 63B, the fourth surface electrode 64B, and the fifth surface electrode 65B are arranged closer to the second substrate side surface 24 than the imaginary center line VC. The first surface electrode 61A, the second surface electrode 62A, the third surface electrode 63A, the fourth surface electrode 64A, and the fifth surface electrode 65A are in a line-symmetric relationship with the first surface electrode 61B, the second surface electrode 62B, the third surface electrode 63B, the fourth surface electrode 64B, and the fifth surface electrode 65B with respect to the imaginary center line VC. For this reason, in the following, the first surface electrode 61A, the second surface electrode 62A, the third surface electrode 63A, the fourth surface electrode 64A, and the fifth surface electrode 65A will be described in detail, and a detailed description of the first surface electrode 61B, the second surface electrode 62B, the third surface electrode 63B, the fourth surface electrode 64B, and the fifth surface electrode 65B will be omitted.

[0017] 2, the first surface electrode 61A and the fifth surface electrode 65A are disposed in a dispersed manner at both ends in the Y direction of the substrate surface 21. The first surface electrode 61A is disposed at an end of the substrate surface 21 closer to the third substrate side surface 25. The fifth surface electrode 65A is disposed at an end of the substrate surface 21 closer to the fourth substrate side surface 26. Both the first surface electrode 61A and the fifth surface electrode 65A are disposed at positions adjacent to the imaginary center line VC in the X direction.

[0018] Both the first surface electrode 61A and the fifth surface electrode 65A are 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 X direction dimension of the first surface electrode 61A and the X direction dimension of the fifth surface electrode 65A are equal to each other. The Y direction dimension of the fifth surface electrode 65A is larger than the Y direction dimension of the first surface electrode 61A.

[0019] The second surface electrode 62A is disposed between the first surface electrode 61A and the fifth surface electrode 65A in the Y direction. The second surface electrode 62A is formed in a substantially L-shape in a 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 has a smaller dimension in the X direction. The wide portion 62AB is a portion of the second surface electrode 62A that has a larger 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 adjacent to the first surface electrode 61A in the Y direction. The wide portion 62AB is disposed adjacent to the fifth surface electrode 65A in the Y direction. The wide portion 62AB protrudes toward the first substrate side surface 23 relative to the narrow portion 62AA. The dimension in the X direction of the narrow portion 62AA is smaller than the dimension in the X direction of the first surface electrode 61A. The dimension in the X direction of the wide portion 62AB is larger than the dimension in the X direction of the fifth surface electrode 65A.

[0020] The third surface electrode 63A is formed to surround the wide portion 62AB of the second surface electrode 62A from the first substrate side surface 23 side and the third substrate side surface 25 side. 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.

[0021] The first opposing portion is located closer to the third substrate side surface 25 than the wide portion 62AB and faces the narrow portion 62AA in the X direction. The first opposing portion is disposed in a position adjacent to the narrow portion 62AA in the X direction. The second opposing portion is located closer to the first substrate side surface 23 than the wide portion 62AB and adjacent to the wide portion 62AB in the X direction. The connecting portion connects the first opposing portion and the second opposing portion. The connecting portion extends obliquely toward the first substrate side surface 23 as it moves from the first opposing portion to the second opposing portion. In the example shown in FIG. 2, the third surface electrode 63A is composed of wiring having a constant width.

[0022] The fourth surface electrode 64A includes a portion formed from the third substrate side surface 25 to the fourth substrate side surface 26 at an end of the substrate surface 21 closer to the first substrate side surface 23. The fourth surface electrode 64A includes a recessed portion 64AA that accommodates a portion of the first surface electrode 61A and a recessed portion 64AB that accommodates a portion of the third surface electrode 63A and a portion of the wide portion 62AB of the second surface electrode 62A. The end of the fourth surface electrode 64A closer to the fourth substrate side surface 26 in the Y direction is formed adjacent to the fifth surface electrode 65A in the X direction and adjacent to the wide portion 62AB in the Y direction. The fourth surface electrode 64A includes a wiring portion 64AC formed adjacent to the narrow portion 62AA in the X direction. The wiring portion 64AC constitutes a portion of the recessed portion 64AA. The wiring portion 64AC is disposed between the first surface electrode 61A and the third surface electrode 63A in the Y direction.

[0023] (Rear Surface Electrodes) As shown in FIG. 3 , multiple rear surface electrodes 28B are formed on the rear surface 22 of the substrate. The multiple rear surface electrodes 28B are electrically connected to the multiple front surface electrodes 28A and form the mounting surface of the semiconductor light-emitting device 10. The multiple rear surface electrodes 28B include first rear surface electrodes 71A, 71B, second rear surface electrodes 72A, 72B, third rear surface electrodes 73A, 73B, and fourth rear surface electrodes 74A, 74B, which are spaced apart from one another. The second rear surface electrodes 72A, 72B, third rear surface electrodes 73A, 73B, and fourth rear surface electrodes 74A, 74B form external electrode terminals electrically connected to a circuit board when the semiconductor light-emitting device 10 is mounted on the circuit board. The first rear surface electrodes 71A, 71B are heat dissipation electrodes for dissipating heat to the outside of the semiconductor light-emitting device 10.

[0024] 3 , the first back surface electrode 71A, the second back surface electrode 72A, the third back surface electrode 73A, and the fourth back surface electrode 74A are arranged closer to the first substrate side surface 23 than the imaginary center line VC. The first back surface electrode 71B, 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 imaginary center line VC. The first back surface electrode 71A, the second back surface electrode 72A, the third back surface electrode 73A, and the fourth back surface electrode 74A and the first back surface electrode 71B, the second back surface electrode 72B, the third back surface electrode 73B, and the fourth back surface electrode 74B are in an axisymmetric relationship with respect to the imaginary center line VC. For this reason, in the following, the first back surface electrode 71A, the second back surface electrode 72A, the third back surface electrode 73A, and the fourth back surface electrode 74A will be described in detail, and a detailed description of the first back surface electrode 71B, the second back surface electrode 72B, the third back surface electrode 73B, and the fourth back surface electrode 74B will be omitted.

[0025] The first back surface electrode 71A is a back surface electrode electrically connected to the first surface electrode 61A and the fifth surface electrode 65A (see FIG. 1 for both). That is, the first surface electrode 61A and the fifth surface electrode 65A are electrically connected via the first back surface electrode 71A. The first back surface electrode 71A is disposed at a position adjacent to the imaginary center line VC in the X direction. The first back surface electrode 71A is formed from the third substrate side surface 25 to the fourth substrate side surface 26 in the Y direction. Therefore, the first back surface electrode 71A includes a portion overlapping with the first surface electrode 61A in a plan view and a portion overlapping with the fifth surface electrode 65A in a plan view.

[0026] The second to fourth back surface electrodes 72A to 74A are arranged closer to the first substrate side surface 23 than the first back surface electrode 71A. The second back surface electrode 72A and the third back surface electrode 73A are arranged closer to the fourth substrate side surface 26 than the center in the Y direction of the substrate back surface 22. The second back surface electrode 72A and the third back surface electrode 73A are arranged side by side in the X direction. The second back surface electrode 72A is arranged closer to the first back surface electrode 71A than the third back surface electrode 73A. The fourth back surface electrode 74A is formed to surround the second back surface electrode 72A and the third back surface electrode 73A from the first substrate side surface 23 and the third substrate side surface 25.

[0027] The second back surface electrode 72A is an electrode electrically connected to the second surface electrode 62A (see FIG. 1). The second back surface electrode 72A is formed in a strip shape extending in the Y direction. 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.

[0028] The third back surface electrode 73A is an electrode electrically connected to the third surface electrode 63A (see FIG. 1 ). The third back surface electrode 73A is formed in a strip shape extending in the Y direction. The dimension of the third back surface electrode 73A in the Y direction is smaller than the dimension of the second back surface electrode 72A in the Y direction. 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.

[0029] The fourth back surface electrode 74A is an electrode electrically connected to the fourth surface electrode 64A (see FIG. 1 ). The fourth back surface electrode 74A includes a first portion 74AA that is square in plan view and is formed closer to the third substrate side surface 25 than the center in the Y direction of the substrate back surface 22, and a strip-shaped second portion 74AB that extends in the Y direction from the first portion 74AA toward the fourth substrate side surface 26. The second portion 74AB is disposed closer to the first substrate side surface 23 than the third back surface electrode 73A. The fourth back surface electrode 74A includes a portion that overlaps with the fourth surface electrode 64A in plan view.

[0030] 3, in a plan view, the area of ​​the first back surface electrode 71A is larger than the area of ​​each of the second to fourth back surface electrodes 72A to 74A. In one example, the area of ​​the first back surface electrode 71A is larger than the total area of ​​the second to fourth back surface electrodes 72A to 74A.

[0031] 5, the plurality of surface-side intermediate electrodes 28C are formed in 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. 4 for both). The plurality of surface-side intermediate electrodes 28C include first intermediate electrodes 81A, 81B, second intermediate electrodes 82A, 82B, third intermediate electrodes 83A, 83B, and fourth intermediate electrodes 84A, 84B, which are arranged at a distance from one another.

[0032] 5 , the first intermediate electrode 81A, the second intermediate electrode 82A, the third intermediate electrode 83A, and the fourth intermediate electrode 84A are arranged closer to the first substrate side surface 23 than the imaginary center line VC. The first intermediate electrode 81B, the second intermediate electrode 82B, the third intermediate electrode 83B, and the fourth intermediate electrode 84B are arranged closer to the second substrate side surface 24 than the imaginary center line VC. The first intermediate electrode 81A, the second intermediate electrode 82A, the third intermediate electrode 83A, and the fourth intermediate electrode 84A are in a line-symmetric relationship with the first intermediate electrode 81B, the second intermediate electrode 82B, the third intermediate electrode 83B, and the fourth intermediate electrode 84B with respect to the imaginary center line VC. Therefore, in the following, we will provide a detailed description of the first intermediate electrode 81A, the second intermediate electrode 82A, the third intermediate electrode 83A, and the fourth intermediate electrode 84A, and will omit a detailed description of the first intermediate electrode 81B, the second intermediate electrode 82B, the third intermediate electrode 83B, and the fourth intermediate electrode 84B.

[0033] The first intermediate electrode 81A is a back surface electrode that electrically connects the first surface electrode 61A and the fifth surface electrode 65A (see FIG. 1 ). That is, the first surface electrode 61A and the fifth surface electrode 65A are electrically connected via the first intermediate electrode 81A. The first intermediate electrode 81A is also electrically connected to the first back surface electrode 71A (see FIG. 3 ). The first intermediate electrode 81A is disposed adjacent to the imaginary center line VC in the X direction. The first intermediate electrode 81A is formed from the third substrate side surface 25 to the fourth substrate side surface 26 in the Y direction. Therefore, the first intermediate electrode 81A includes a portion that overlaps with the first surface electrode 61A in a plan view and a portion that overlaps with the fifth surface electrode 65A in a plan view.

[0034] The second intermediate electrode 82A electrically connects the second surface electrode 62A (see FIG. 1) and the second back surface electrode 72A (see FIG. 3). The third intermediate electrode 83A electrically connects the third surface electrode 63A (see FIG. 1) and the third back surface electrode 73A (see FIG. 3). The second intermediate electrode 82A and the third intermediate electrode 83A are disposed within the electrode accommodating portion of the fourth intermediate electrode 84A. The electrode accommodating portion has a generally concave shape extending in the X direction and opening toward the imaginary center line VC. The second intermediate electrode 82A and the third intermediate electrode 83A are disposed side by side in the X direction. The second intermediate electrode 82A is disposed closer to the first intermediate electrode 81A than the third intermediate electrode 83A. The second intermediate electrode 82A is formed in a generally right-angled trapezoid shape. 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. The second intermediate electrode 82A includes a portion that overlaps with both the wide portion 62AB of the second surface electrode 62A (see FIG. 1) and the second back surface electrode 72A in a plan view. The third intermediate electrode 83A includes a portion that overlaps with both the second opposing portion of the third surface electrode 63A (see FIG. 1) and the third back surface electrode 73A (see FIG. 3) in a plan view.

[0035] The fourth intermediate electrode 84A is an electrode that electrically connects the fourth surface electrode 64A (see FIG. 1) and the fourth back surface electrode 74A (see FIG. 3). The fourth intermediate electrode 84A is formed over most of a portion of the substrate surface of the intermediate substrate 27C that is closer to the first substrate side surface 23 than the first intermediate electrode 81A. The fourth intermediate electrode 84A includes portions that overlap with both the fourth surface electrode 64A (see FIG. 1) and the fourth back surface electrode 74A (see FIG. 3).

[0036] 1 to 5 , the substrate 20 includes first vias 91A and 91B, second vias 92A and 92B, third vias 93A and 93B, fourth vias 94A and 94B, and fifth vias 95A and 95B. The first vias 91A and 91B, second vias 92A and 92B, third vias 93A and 93B, fourth vias 94A and 94B, and fifth vias 95A and 95B 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 91A and 91B, the second vias 92A and 92B, the third vias 93A and 93B, the fourth vias 94A and 94B, and the fifth vias 95A and 95B may be provided to penetrate the front surface electrode 28A and the back surface electrode 28B in the Z direction. The first vias 91A and 91B, the second vias 92A and 92B, the third vias 93A and 93B, the fourth vias 94A and 94B, and the fifth vias 95A and 95B are formed of a material containing one or more appropriately selected from Ti, TiN, Au, Ag, Cu, Al, and W, for example.

[0037] 1 to 5, the first via 91A, the second via 92A, the third via 93A, the fourth via 94A, and the fifth via 95A are arranged closer to the first substrate side surface 23 than the imaginary center line VC. The first via 91B, the second via 92B, the third via 93B, the fourth via 94B, and the fifth via 95A are arranged closer to the second substrate side surface 24 than the imaginary center line VC. The first to fifth vias 91A to 95A and the first to fifth vias 91B to 95B are in an axisymmetric relationship with respect to the imaginary center line VC. For this reason, the first to fifth vias 91A to 95A will be described in detail below, and a detailed description of the first to fifth vias 91B to 95B will be omitted.

[0038] A plurality of each of the first to fifth vias 91A to 95A is provided. The number of the first vias 91A and the number of the fifth vias 95A are the same, and the number of each of the second to fourth vias 92A to 94A is less than the number of the first vias 91A. The number of the fourth vias 94A is greater than the number of each of the second vias 92A and the third vias 93A. The number of the third vias 93A is less than the number of the second vias 92A.

[0039] The first via 91A is electrically connected to the first surface electrode 61A, the first intermediate electrode 81A of the surface-side intermediate electrode 28C, the first intermediate electrode 81A of the back-side intermediate electrode 28D, and the first back-side electrode 71A. As a result, the first surface electrode 61A, the first intermediate electrode 81A of the surface-side intermediate electrode 28C, the first intermediate electrode 81A of the back-side intermediate electrode 28D, and the first back-side electrode 71A are electrically connected to one another.

[0040] The fifth via 95A is electrically connected to the fifth surface electrode 65A, the first intermediate electrode 81A of the front-side intermediate electrode 28C, the first intermediate electrode 81A of the back-side intermediate electrode 28D, and the first back-side electrode 71A. As a result, the fifth surface electrode 65A, the first intermediate electrode 81A of the front-side intermediate electrode 28C, the first intermediate electrode 81A of the back-side intermediate electrode 28D, and the first back-side electrode 71A are electrically connected to one another. In other words, the first surface electrode 61A and the fifth surface electrode 65A are electrically connected to one another by the first via 91A, the first intermediate electrode 81A of the front-side intermediate electrode 28C, the first intermediate electrode 81A of the back-side intermediate electrode 28D, the first back-side electrode 71A, and the fifth via 95A.

[0041] As shown in FIG. 2 , the multiple first vias 91A are provided in the first surface electrode 61A. Therefore, in a plan view, the multiple first vias 91A are arranged in positions of the first surface electrode 61A that overlap with the first semiconductor light emitting element 30A. The multiple first vias 91A are arranged at intervals 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 first semiconductor light emitting element 30A. Therefore, some of the multiple first vias 91A are provided outward from the first semiconductor light emitting element 30A in a plan view.

[0042] The plurality of fifth vias 95A are, for example, the same in number as the plurality of first vias 91A, and are also arranged in the same manner. The plurality of fifth vias 95A are provided in a portion of the fifth surface electrode 65A closer to the fourth substrate side surface 26.

[0043] 1 to 5, the plurality of 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. As shown in Fig. 2, the plurality of second vias 92A are provided at an end of the wide portion 62AB of the second surface electrode 62A that is closer to the first substrate side surface 23.

[0044] 1 to 5, the plurality of third vias 93A are electrically connected to the third surface electrode 63A, the third intermediate electrode 83A of the front-side intermediate electrode 28C, the third intermediate electrode 83A of the rear-side intermediate electrode 28D, and the third rear-surface electrode 73A. As a result, the third surface electrode 63A, the third intermediate electrode 83A of the front-side intermediate electrode 28C, the third intermediate electrode 83A of the rear-surface intermediate electrode 28D, and the third rear-surface electrode 73A are electrically connected to one another. As shown in FIG. 2, the plurality of third vias 93A are provided in the second opposing portion of the third surface electrode 63A.

[0045] As shown in FIGS. 1 to 5 , the fourth vias 94A are 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. As shown in FIG. 2 , the fourth vias 94A are provided at the end of the fourth surface electrode 64A in the Y direction that is closer to the third substrate side surface 25. The fourth vias 94A are arranged spaced apart from one another in the X and Y directions. The number of fourth vias 94A arranged in the X direction is greater than the number of fourth vias 94A arranged in the Y direction.

[0046] 4, 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.

[0047] The surface resist 29A includes openings that expose portions of the plurality of surface electrodes 28A. The first semiconductor light emitting element 30A, the second semiconductor light emitting element 30B, the components of the first drive circuit 40A, and the components of the second drive circuit 40B are mounted on the surface electrodes 28A exposed by the openings in the surface resist 29A. Note that in Figures 1 and 2, the openings in the surface resist 29A are indicated by two-dot chain lines.

[0048] 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. 7 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. 3, the openings in the back surface resist 29B are indicated by two-dot chain lines.

[0049] 1, a first semiconductor light emitting element 30A, a second semiconductor light emitting element 30B, a first drive circuit 40A, a second drive circuit 40B, a first protection diode 50A, and a second protection diode 50B are mounted on the plurality of surface electrodes 28A. That is, the semiconductor light emitting device 10 of the first embodiment includes the first protection diode 50A and the second protection diode 50B. The first semiconductor light emitting element 30A, the first drive circuit 40A, and the first protection diode 50A are arranged closer to the first substrate side surface 23 than the imaginary center line VC. The second semiconductor light emitting element 30B, the second drive circuit 40B, and the second protection diode 50B are arranged closer to the second substrate side surface 24 than the imaginary center line VC. The mounting positions of the first semiconductor light emitting element 30A, the first drive circuit 40A, and the first protection diode 50A and the mounting positions of the second semiconductor light emitting element 30B, the second drive circuit 40B, and the second protection diode 50B are in a line-symmetrical relationship with respect to the imaginary center line VC. Additionally, the configurations of the first semiconductor light emitting element 30A, the first drive circuit 40A, and the first protection diode 50A are the same as the configurations of the second semiconductor light emitting element 30B, the second drive circuit 40B, and the second protection diode 50B. Therefore, the following will describe the detailed configurations and mounting aspects of the first semiconductor light emitting element 30A, the first drive circuit 40A, and the first protection diode 50A with reference to FIGS. 2 and 3 , and will omit a description of the configurations and mounting aspects of the second semiconductor light emitting element 30B, the second drive circuit 40B, and the second protection diode 50B.

[0050] 2 and 4, the first semiconductor light emitting element 30A is mounted on the first surface electrode 61A. More specifically, as shown in Fig. 4, the first semiconductor light emitting element 30A is joined to the first surface electrode 61A by a conductive bonding material SD. The conductive bonding material SD may be solder paste, silver paste, gold paste, or copper paste.

[0051] 2, the first semiconductor light emitting element 30A is disposed at one of the ends of the first surface electrode 61A in the X direction that is closer to the imaginary center line VC. In a plan view, the first semiconductor light emitting element 30A is disposed adjacent to the imaginary center line VC. Therefore, as shown in FIG. 1, the first semiconductor light emitting element 30A and the second semiconductor light emitting element 30B are disposed adjacent to each other in the X direction. Furthermore, the first semiconductor light emitting element 30A is disposed closer to the third substrate side surface 25 than the center of the first surface electrode 61A in the Y direction.

[0052] The first semiconductor light emitting element 30A is formed in a rectangular plate shape with its thickness direction aligned in the Z direction. In plan view, the shape of the first semiconductor light emitting element 30A is a rectangle (oblong) with its longitudinal direction aligned in the X direction and its lateral direction aligned in the Y direction.

[0053] The first semiconductor light-emitting element 30A 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 first semiconductor light-emitting element 30A is, for example, an edge-emitting laser (EEL). The first semiconductor light-emitting element 30A includes multiple (four 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 first semiconductor light-emitting element 30A 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 multiple light-emitting portions 33 are arranged side by side in the X direction.

[0054] As shown in FIG. 4 , the first semiconductor light emitting element 30A includes a front surface 31 and a back surface 32 facing opposite to each other in the Z direction. As shown in FIG. 1 , the front surface 31 includes multiple (four in the first embodiment) front surface electrodes 34. The number of front surface electrodes 34 is set according to the number of light emitting portions 33. That is, the multiple front surface electrodes 34 are provided individually for the multiple light emitting portions 33. The multiple front surface electrodes 34 are individually electrically connected to the multiple light emitting portions 33. The multiple front surface electrodes 34 are arranged at the same positions in the Y direction and spaced apart from each other in the X direction. In one example, the multiple front surface electrodes 34 form anode electrodes for the multiple light emitting portions 33. Here, the front surface electrodes 34 of the first semiconductor light emitting element 30A form a first anode electrode. The back surface electrode 35 of the first semiconductor light emitting element 30A forms a first cathode electrode.

[0055] 4 , 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. That is, 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.

[0056] 2, the first drive circuit 40A is configured to drive the first semiconductor light emitting element 30A. The first drive circuit 40A includes a first switching element 411 that controls the drive of the first semiconductor light emitting element 30A, and a first capacitor 421 that supplies current to the first semiconductor light emitting element 30A. The first switching element 411 and the first capacitor 421 are arranged at a distance from the first semiconductor light emitting element 30A.

[0057] In a plan view, the first semiconductor light emitting element 30A and the first switching element 411 are spaced apart from each other in the Y direction. The first switching element 411 is mounted on the second surface electrode 62A. More specifically, as shown in FIG. 4 , the first switching element 411 is joined to the second surface electrode 62A with a conductive bonding material SD.

[0058] 2, the first switching element 411 is mainly mounted on the narrow portion 62AA of the second surface electrode 62A. A portion of the first switching element 411 protrudes into the wide portion 62AB of the second surface electrode 62A. In other words, the first switching element 411 is disposed on the second surface electrode 62A near the first semiconductor light emitting element 30A. When viewed from the Y direction, the first switching element 411 is disposed in a position overlapping with the first semiconductor light emitting element 30A.

[0059] For example, a vertical transistor is used as the first switching element 411. For example, a transistor such as a metal-oxide-semiconductor field-effect transistor (MOSFET), an insulated gate bipolar transistor (IGBT), or a bipolar transistor is used as the first switching element 411. In the first embodiment, an n-type MOSFET is used as the first switching element 411.

[0060] The first switching element 411 is formed in a rectangular plate shape with its thickness direction aligned in the Z direction. The first switching element 411 is formed in a square shape in plan view. The shape of the first switching element 411 in plan view can be changed as desired.

[0061] 4, the first switching element 411 includes an element front surface 41A and an element back surface 41B that face opposite each other in the Z direction. The element front surface 41A faces the same side as the substrate front surface 21, and the element back surface 41B faces the same side as the substrate back surface 22. In other words, the element back surface 41B faces the second surface electrode 62A.

[0062] As shown in FIG. 2 , a source electrode 41S and a gate electrode 41G are formed on the element surface 41A of the first switching element 411. The source electrode 41S is formed over most of the element surface 41A. The gate electrode 41G is formed at an end of the element surface 41A closer to the first substrate side surface 23 in the X direction and at the center of the 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 facing portion of the third surface electrode 63A in the X direction. In a plan view, the source electrode 41S includes a portion facing the wiring portion 64AC of the fourth surface electrode 64A in the X direction.

[0063] 4, a drain electrode 41D is formed on the element back surface 41B of the first switching element 411. The drain electrode 41D is formed over the entire element back surface 41B. The drain electrode 41D is joined to the second surface electrode 62A with a conductive bonding material SD. In other words, the drain electrode 41D of the first switching element 411 is mounted on the second surface electrode 62A. In this way, the drain electrode 41D of the first switching element 411 is mounted on the multiple surface electrodes 28A.

[0064] 2, the source electrode 41S of the first switching element 411 and the plurality of element surface electrodes 34 are individually and electrically connected by a plurality of wires W1. The source electrode 41S of the first switching element 411 and the fourth surface electrode 64A are electrically connected by a wire W2. The gate electrode 41G of the first switching element 411 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.

[0065] In a plan view, the first semiconductor light emitting element 30A and the first capacitor 421 are arranged spaced apart from each other in the Y direction. The first capacitor 421 is arranged on the opposite side of the first semiconductor light emitting element 30A in the Y direction with respect to the first switching element 411. In other words, in a plan view, the first switching element 411 is arranged between the first semiconductor light emitting element 30A and the first capacitor 421 in the Y direction. The first switching element 411 is arranged closer to the first semiconductor light emitting element 30A in the Y direction than the first capacitor 421. In other words, the distance between the first switching element 411 and the first semiconductor light emitting element 30A in the Y direction is smaller than the distance between the first switching element 411 and the first capacitor 421 in the Y direction.

[0066] A ceramic capacitor is used as the first capacitor 421 in the first embodiment. A plurality of first capacitors 421 (six in the first embodiment) are provided. The plurality of first capacitors 421 are arranged spaced apart from one another in the X direction. Each first capacitor 421 is arranged to straddle the second surface electrode 62A and the fifth surface electrode 65A in the Y direction. Each first capacitor 421 is mounted on the second surface electrode 62A and the fifth surface electrode 65A. More specifically, as shown in FIG. 4 , each first capacitor 421 is individually joined to the second surface electrode 62A and the fifth surface electrode 65A by a conductive bonding material SD.

[0067] Each first capacitor 421 includes a first electrode 42A and a second electrode 42B. In each first capacitor 421, 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. 2 , 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 fifth surface electrode 65A by a conductive bonding material SD. This electrically connects the second electrode 42B to the fifth surface electrode 65A.

[0068] The first electrode 42A of each first capacitor 421 is disposed on the wide portion 62AB of the second surface electrode 62A. In the example of FIG. 2 , the first electrode 42A is disposed at the end of the wide portion 62AB closer to the fifth surface electrode 65A in the Y direction. The X-direction dimension of the arrangement area of ​​the multiple first capacitors 421 aligned in the X direction is greater than the X-direction dimension of the narrow portion 62AA. In other words, some of the multiple first capacitors 421 are disposed closer to the first substrate side surface 23 than the narrow portion 62AA when viewed from the Y direction. Some of the multiple first capacitors 421 are disposed closer to the first substrate side surface 23 than the first switching element 411 when viewed from the Y direction.

[0069] The second electrode 42B of each first capacitor 421 is disposed at one of the Y-direction ends of the fifth surface electrode 65A that is closer to the second surface electrode 62A. That is, the second electrode 42B of each first capacitor 421 is disposed closer to the second surface electrode 62A in the Y-direction than the plurality of fifth vias 95A. The plurality of first capacitors 421 arranged in the X-direction are disposed across the entire fifth surface electrode 65A in the X-direction. In other words, the dimension of the fifth surface electrode 65A in the X-direction is set so that the plurality of first capacitors 421 arranged in the X-direction can be disposed thereon.

[0070] 1, the distance D1 in the Y direction between the first semiconductor light emitting element 30A and the first switching element 411 is equal to the distance D2 in the Y direction between the second semiconductor light emitting element 30B and the second switching element 412. 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.

[0071] As shown in FIG. 2 , the first protection diode 50A protects the light-emitting portion 33 of the first semiconductor light-emitting element 30A. The first protection diode 50A is disposed closer to the first substrate side surface 23 than the first semiconductor light-emitting element 30A and the first switching element 411 in the X direction. The first protection diode 50A is disposed on the opposite side of the first semiconductor light-emitting element 30A from the first switching element 411 in the Y direction. The first protection diode 50A is disposed closer to the fourth substrate side surface 26 than the multiple first capacitors 421. The first protection diode 50A is disposed so as to straddle the fourth surface electrode 64A and the fifth surface electrode 65A in the X direction. The first protection diode 50A is mounted on the fourth surface electrode 64A and the fifth surface electrode 65A. More specifically, the first protection diode 50A is individually bonded to the fourth surface electrode 64A and the fifth surface electrode 65A by a conductive bonding material SD (not shown).

[0072] The first protection diode 50A is connected in anti-parallel to the first semiconductor light emitting element 30A. More specifically, the first protection diode 50A includes an anode electrode 51 and a cathode electrode 52. The first protection diode 50A is arranged so that the anode electrode 51 and the cathode electrode 52 are at the same position in the Y direction and spaced apart in the X direction. The anode electrode 51 is bonded to the fifth surface electrode 65A by a conductive bonding material SD. The anode electrode 51 is disposed on the fifth surface electrode 65A. This electrically connects the anode electrode 51 to the back surface electrode 35 of the first semiconductor light emitting element 30A via the fifth surface electrode 65A. The cathode electrode 52 is bonded to the fourth surface electrode 64A by a conductive bonding material SD. This electrically connects the cathode electrode 52 to the front surface electrode 34 of the first semiconductor light emitting element 30A via the wire W2, the source electrode 41S of the first switching element 411, and the wire W1.

[0073] Next, an overview of the configuration of the second semiconductor light emitting element 30B and the second drive circuit 40B will be described. As shown in FIG. 1 , the second semiconductor light emitting element 30B has the same configuration as the first semiconductor light emitting element 30A, and therefore includes a front surface electrode 34 and a back surface electrode 35. The front surface electrode 34 of the second semiconductor light emitting element 30B constitutes a second anode electrode. The back surface electrode 35 of the second semiconductor light emitting element 30B constitutes a second cathode electrode.

[0074] The second drive circuit 40B is configured to drive the second semiconductor light emitting element 30B. The second drive circuit 40B includes a second switching element 412 that controls the drive of the second semiconductor light emitting element 30B, and a capacitor 421 that supplies current to the second semiconductor light emitting element 30B. Because the second switching element 412 has the same configuration as the first switching element 411, the same reference numerals as the first switching element 411 are used for the components of the second switching element 412. Because the second capacitor 422 has the same configuration as the first capacitor 421, the same reference numerals as the first capacitor 421 are used for the components of the second capacitor 422.

[0075] In a plan view, the second semiconductor light emitting element 30B and the second switching element 412 are arranged spaced apart from each other in the Y direction. In a plan view, the second switching element 412 is arranged between the second semiconductor light emitting element 30B and the second capacitor 422 in the Y direction. The second switching element 412 is arranged closer to the second semiconductor light emitting element 30B than the second capacitor 422 in the Y direction.

[0076] The drain electrode 41D of the second switching element 412 is electrically connected to the second surface electrode 62B, the source electrode 41S is electrically connected to the fourth surface electrode 64B, and the gate electrode 41G is electrically connected to the third surface electrode 63B. In addition, the source electrode 41S of the second switching element 412 is electrically connected to the element surface electrode 34 (anode electrode) of the second semiconductor light emitting element 30B by a wire W1.

[0077] [Circuit Configuration of Semiconductor Light-Emitting Device] As shown in Figure 6, a light-emitting system 800 including a 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, gate driver ICs 805A and 805B, pulse generators 806A and 806B, and control power supplies 807A and 807B. In the light-emitting system 800 of the first embodiment, a gate driver IC, pulse generator, and control power supply are provided for each of the first drive circuit 40A and the second drive circuit 40B. In the following description, please refer to Figures 1 to 5 for the components of the surface electrode 28A, switching elements 411 and 412, capacitors 421 and 422, and protection diodes 50A and 50B.

[0078] The DC power supply 801, the capacitor 802, and the current limiting resistor 803 are configured to supply current to the first semiconductor light emitting element 30A, the second semiconductor light emitting element 30B, the first drive circuit 40A, and the second drive circuit 40B. Therefore, the DC power supply 801, the capacitor 802, and the current limiting resistor 803 are an example of a "power supply input unit."

[0079] 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.

[0080] The gate driver IC 805A is electrically connected to the gate electrode 41G of the first switching element 411 of the first drive circuit 40A. The gate driver IC 805A is electrically connected to the third back surface electrode 73A to which the gate electrode 41G of the first switching element 411 is electrically connected. The gate driver IC 805A is configured to drive the first switching element 411. The gate driver IC 805A is configured to apply a gate voltage signal to the gate electrode 41G of the first switching element 411. The first switching element 411 performs an on / off operation based on the gate voltage signal. Here, the gate driver IC 805A is an example of a "first gate drive circuit."

[0081] The pulse generator 806A and the control power supply 807A are electrically connected to the gate driver IC 805A. The pulse generator 806A is configured to output a pulse signal to the gate driver IC 805A for controlling the first switching element 411. The control power supply 807A is a power supply for operating the gate driver IC 805A. The control power supply 807A is configured to apply an operating voltage to the gate driver IC 805A.

[0082] The gate driver IC 805B is electrically connected to the gate electrode 41G of the second switching element 412 of the second drive circuit 40B. The gate driver IC 805B is electrically connected to the third back surface electrode 73B to which the gate electrode 41G of the second switching element 412 is electrically connected. The gate driver IC 805B is configured to drive the second switching element 412. The gate driver IC 805B is configured to apply a gate voltage signal to the gate electrode 41G of the second switching element 412. The second switching element 412 performs an on / off operation based on the gate voltage signal. Here, the gate driver IC 805B is an example of a "second gate drive circuit."

[0083] The pulse generator 806B and the control power supply 807B are electrically connected to the gate driver IC 805B. The pulse generator 806B is configured to output a pulse signal to the gate driver IC 805B for controlling the second switching element 412. The control power supply 807B is a power supply for operating the gate driver IC 805B. The control power supply 807B is configured to apply an operating voltage to the gate driver IC 805B.

[0084] The negative electrode of the DC power supply 801, the capacitor 802, the pulse generator 806A, and the negative electrode of the control power supply 807A are each electrically connected to the fourth back surface electrode 74A. The negative electrode of the DC power supply 801, the capacitor 802, the pulse generator 806A, and the negative electrode of the control power supply 807A are each connected to ground. Therefore, the fourth back surface electrodes 74A and 74B are connected to ground.

[0085] 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 411 and the first electrode 42A of the first capacitor 421 via the second back surface electrode 72A. The cathode of the reverse current prevention diode 804B is electrically connected to both the drain electrode 41D of the second switching element 412 and the first electrode 42A of the second capacitor 422 via the second back surface electrode 72B.

[0086] The source electrode 41S of the first switching element 411 is electrically connected to the first anode electrode (element front surface electrode 34) of the first semiconductor light emitting element 30A. The first cathode electrode (element back surface electrode 35) of the first semiconductor light emitting element 30A is electrically connected to the second electrode 42B of the first capacitor 421 and the anode electrode 51 of the protection diode 50A. The source electrode 41S of the first switching element 411 is electrically connected to the fourth back surface electrode 74A via the fourth surface electrode 64A. The cathode electrode 52 of the first protection diode 50A is electrically connected to the fourth back surface electrode 74A via the fourth surface electrode 64A.

[0087] The connection configuration of the second semiconductor light emitting element 30B, the second switching element 412, the second capacitor 422, and the second protection diode 50B is the same as the connection configuration of the first semiconductor light emitting element 30A, the first switching element 411, the first capacitor 421, and the first protection diode 50A. Therefore, both the source electrode 41S of the second switching element 412 and the cathode electrode 52 of the second protection diode 50B are electrically connected to the fourth back surface electrode 74B. Because the fourth back surface electrodes 74A, 74B form ground terminals connected to ground, the fourth front surface electrodes 64A, 64B electrically connected to the fourth back surface electrodes 74A, 74B form ground wiring.

[0088] The following describes the driving operation of the semiconductor light-emitting elements 30A and 30B in the semiconductor light-emitting device 10. When the first switching element 411 of the first driving circuit 40A is in the OFF state, the first capacitor 421 is charged by the DC power supply 801. When the first switching element 411 is changed from the OFF state to the ON state, a current flows from the first capacitor 421 to the first semiconductor light-emitting element 30A via the first switching element 411. This causes pulsed laser light to be emitted from the light-emitting portion 33 of the first semiconductor light-emitting element 30A.

[0089] Furthermore, when the second switching element 412 of the second drive circuit 40B is in the OFF state, the second capacitor 422 is charged by the DC power supply 801. Then, when the second switching element 412 is changed from the OFF state to the ON state, current flows from the second capacitor 422 via the second switching element 412 to the light-emitting unit 33 of the second semiconductor light-emitting element 30B. This causes pulsed laser light to be emitted from the light-emitting unit 33. In this way, the first drive circuit 40A controls the driving of the first semiconductor light-emitting element 30A, and the second drive circuit 40B controls the driving of the second semiconductor light-emitting element 30B. In other words, the first drive circuit 40A and the second drive circuit 40B individually control the first semiconductor light-emitting element 30A and the second semiconductor light-emitting element 30B.

[0090] As an example, the first semiconductor light-emitting element 30A and the second semiconductor light-emitting element 30B are sequentially driven by the first drive circuit 40A and the second drive circuit 40B. In this case, the pulsed light emissions of the first semiconductor light-emitting element 30A and the second semiconductor light-emitting element 30B can be adjusted so that the pulse intervals of the laser light emitted by the semiconductor light-emitting device 10 are shorter than in a semiconductor light-emitting device including, for example, a single semiconductor light-emitting element. This allows for an increase in the number of pulses per unit time. In addition, by alternately emitting light from the first semiconductor light-emitting element 30A and the second semiconductor light-emitting element 30B, heat generation from each of the semiconductor light-emitting elements 30A and 30B can be suppressed compared to a semiconductor light-emitting device including a single semiconductor light-emitting element.

[0091] Furthermore, since each of the first semiconductor light-emitting element 30A and the second semiconductor light-emitting element 30B includes multiple (four in the first embodiment) light-emitting portions 33, the average output power of the laser light can be increased compared to a semiconductor light-emitting device including one semiconductor light-emitting element including one light-emitting portion.

[0092] [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 employs a semiconductor light emitting element including multiple (eight in the first embodiment) light emitting sections. As the output power of the semiconductor light emitting element increases, the amount of heat generated by the semiconductor light emitting element also increases. For this reason, the semiconductor light emitting device requires a structure for dissipating heat from the semiconductor light emitting element.

[0093] Therefore, in the semiconductor light emitting device 10 of the first embodiment, the first semiconductor light emitting element 30A and the second semiconductor light emitting element 30B are mounted on first surface electrodes 61A, 61B 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. 7, 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.

[0094] In particular, as shown in FIG. 7 , the first back surface electrode 71A formed over most of the substrate back surface 22 is bonded to the wiring 901 of the circuit board 900 by the conductive bonding material SDA. Therefore, heat from the first semiconductor light emitting element 30A is transferred to the wiring 901 via the conductive bonding material SD bonded to the element back surface electrode 35, the first front surface electrode 61A, the multiple first vias 91A, the first back surface electrode 71A, and the conductive bonding material SDA. Here, compared to a semiconductor laser device with a CAN-type package structure, for example, mounted on a circuit board using multiple leads, the bonding area between the first back surface electrode 71A, the conductive bonding material SDA, and the wiring 901 is larger, making it easier for heat from the first semiconductor light emitting element 30A to transfer to the circuit board 900. The heat dissipation structure of the second semiconductor light emitting element 30B is the same as that of the first semiconductor light emitting element 30A described above. Therefore, heat is also more easily transferred to the circuit board 900 in the second semiconductor light emitting element 30B, as in the first semiconductor light emitting element 30A.

[0095] 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.

[0096] Meanwhile, LiDAR is required to have a wider viewing angle and improved resolution. To meet such demands, it is conceivable to provide a drive circuit that individually drives the first semiconductor light-emitting element 30A and the second semiconductor light-emitting element 30B as channels. In other words, the light emission timing of the first semiconductor light-emitting element 30A and the light emission timing of the second semiconductor light-emitting element 30B can be shifted, thereby shortening the pulse length of the laser light emitted by the first semiconductor light-emitting element 30A and the second semiconductor light-emitting element 30B and increasing the number of times that the first semiconductor light-emitting element 30A and the second semiconductor light-emitting element 30B emit laser light per unit time.

[0097] However, if such a drive circuit is provided external to the semiconductor light-emitting device 10, the area of ​​the loop-shaped first current path formed by the drive circuit and the first semiconductor light-emitting element 30A and the area of ​​the loop-shaped second current path formed by the drive circuit and the second semiconductor light-emitting element 30B will each be large. As a result, the inductance caused by these current paths increases, making it difficult to further shorten the pulse of the laser light emitted by the first semiconductor light-emitting element 30A and the second semiconductor light-emitting element 30B. In addition, as the lengths of the first current path and the second current path increase, the length of the first current path and the second current path will vary more. As a result, there is a risk of the pulse width of the laser light emitted by the first semiconductor light-emitting element 30A and the second semiconductor light-emitting element 30B varying from each other.

[0098] Therefore, the semiconductor light-emitting device 10 includes a first drive circuit 40A and a second drive circuit 40B that drive the first semiconductor light-emitting element 30A and the second semiconductor light-emitting element 30B, respectively. In other words, the semiconductor light-emitting device 10 incorporates the first drive circuit 40A and the second drive circuit 40B. As shown in FIG. 8 , current flows in the following order: the first electrode 42A of the first capacitor 421, the second surface electrode 62A, the drain electrode 41D and source electrode 41S of the first switching element 411, the wire W1, the element surface electrode 34 of the first semiconductor light-emitting element 30A, the element back surface electrode 35, the first surface electrode 61A, the first intermediate electrode 81A of the surface-side intermediate electrode 28C, and the second electrode 42B of the first capacitor 421. In other words, a loop-shaped first current path is formed by the first semiconductor light-emitting element 30A and the first drive circuit 40A. Although not shown, a loop-shaped second conduction path similar to the first current path is also formed by the second semiconductor light-emitting element 30B and the second drive circuit 40B. Therefore, compared to a configuration in which the drive circuit is provided external to the semiconductor light-emitting device 10, the length and area of ​​the loop-shaped first current path formed by the first semiconductor light-emitting element 30A and the first drive circuit 40A and the length and area of ​​the loop-shaped second current path formed by the second semiconductor light-emitting element 30B and the second drive circuit 40B 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 semiconductor light-emitting element 30A and the second semiconductor light-emitting element 30B, and reduces the variation in the pulse width of the laser light emitted by the first semiconductor light-emitting element 30A and the second semiconductor light-emitting element 30B. In one example, the pulse width of the laser light emitted by the first semiconductor light emitting element 30A and the pulse width of the laser light emitted by the second semiconductor light emitting element 30B are each 4 ns or less. In another example, the absolute value of the variation between the pulse width of the laser light emitted by the first semiconductor light emitting element 30A and the pulse width of the laser light emitted by the second semiconductor light emitting element 30B is 10% or less.

[0099] [Effects] The semiconductor light-emitting device 10 of the first embodiment has the following effects. (1-1) The semiconductor light-emitting device 10 includes a substrate 20 having a substrate front surface 21 and a substrate back surface 22 facing the opposite side to the substrate front surface 21, a plurality of front surface electrodes 28A formed on the substrate front surface 21, a plurality of back surface electrodes 28B formed on the substrate back surface 22, electrically connected to the plurality of front surface electrodes 28A and constituting the mounting surface of the semiconductor light-emitting device 10, a first semiconductor light-emitting element 30A and a second semiconductor light-emitting element 30B including an element front surface electrode 34 and an element back surface electrode 35, a first drive circuit 40A that drives the first semiconductor light-emitting element 30A, and a second drive circuit 40B that drives the second semiconductor light-emitting element 30B. The element back surface electrode 35 of the first semiconductor light-emitting element 30A, the element back surface electrode 35 of the second semiconductor light-emitting element 30B, the first drive circuit 40A, and the second drive circuit 40B are mounted on the plurality of front surface electrodes 28A.

[0100] According to this configuration, the first semiconductor light emitting element 30A and the second semiconductor light emitting element 30B are each mounted on the front surface electrode 28A, and the back surface electrode 28B is formed on the back surface 22 of the substrate. This facilitates transfer of heat from the first semiconductor light emitting element 30A and the second semiconductor light emitting element 30B to the outside of the semiconductor light emitting device 10 via the front surface electrode 28A and the back surface electrode 28B. This prevents the temperatures of the first semiconductor light emitting element 30A and the second semiconductor light emitting element 30B from becoming excessively high. In addition, because the semiconductor light emitting device 10 includes the first drive circuit 40A and the second drive circuit 40B, the area of ​​the first current path between the first semiconductor light emitting element 30A and the first drive circuit 40A and the length of the second current path between the second semiconductor light emitting element 30B and the second drive circuit 40B are each smaller than in a configuration in which the first drive circuit 40A and the second drive circuit 40B are provided outside the semiconductor light emitting device 10. This reduces the inductance due to the lengths of these current paths and reduces the variation in inductance between the first and second current paths, thereby shortening the pulse width of the laser light emitted by the first semiconductor light emitting element 30A and the second semiconductor light emitting element 30B and reducing the variation in the pulse width of the laser light emitted by the first semiconductor light emitting element 30A and the second semiconductor light emitting element 30B.

[0101] (1-2) The first drive circuit 40A includes a first switching element 411 that controls the drive of the first semiconductor light emitting element 30A, and a first capacitor 421 that supplies current to the first semiconductor light emitting element 30A. The second drive circuit 40B includes a second switching element 412 that controls the drive of the second semiconductor light emitting element 30B, and a second capacitor 422 that supplies current to the second semiconductor light emitting element 30B.

[0102] According to this configuration, a loop-shaped first current path formed by the first semiconductor light-emitting element 30A, the first switching element 411, and the first capacitor 421 can be formed within the semiconductor light-emitting device 10. This reduces the area of ​​the first current path, thereby reducing the inductance caused by the area of ​​the first current path. Furthermore, a loop-shaped second current path formed by the second semiconductor light-emitting element 30B, the second switching element 412, and the second capacitor 422 can be formed within the semiconductor light-emitting device 10. This reduces the area of ​​the second current path, thereby reducing the inductance caused by the area of ​​the second current path. Additionally, since the lengths of both the first current path and the second current path are shortened, the variation in the lengths of the first current path and the second current path can be reduced. Therefore, the variation in inductance of the first current path and the second current path can be reduced.

[0103] (1-3) In a plan view, the first semiconductor light emitting element 30A and the first capacitor 421 are arranged spaced apart from each other in the Y direction. In a plan view, the first switching element 411 is arranged between the first semiconductor light emitting element 30A and the first capacitor 421 in the Y direction. In a plan view, the second semiconductor light emitting element 30B and the second capacitor 422 are arranged spaced apart from each other in the Y direction. In a plan view, the second switching element 412 is arranged between the second semiconductor light emitting element 30B and the second capacitor 422 in the Y direction.

[0104] With this configuration, the loop-shaped first current path formed by the first semiconductor light emitting element 30A, the first switching element 411, and the first capacitor 421 can be made shorter than in a configuration in which the first switching element 411 is arranged on the opposite side of the first semiconductor light emitting element 30A with respect to the first capacitor 421 in the Y direction. Also, the loop-shaped second current path formed by the second semiconductor light emitting element 30B, the second switching element 412, and the second capacitor 422 can be made shorter than in a configuration in which the second switching element 412 is arranged on the opposite side of the second semiconductor light emitting element 30B with respect to the second capacitor 422 in the Y direction. In this way, the area of ​​the loop-shaped first current path and the area of ​​the loop-shaped second current path are also reduced, and therefore the inductance of each of the first current path and the second current path can be reduced.

[0105] (1-4) The distance D1 between the first semiconductor light emitting element 30A and the first switching element 411 in the Y direction is equal to the distance D2 between the second semiconductor light emitting element 30B and the second switching element 412 in the Y direction.

[0106] According to this configuration, the length of the current path between the first semiconductor light emitting element 30A and the first switching element 411 is equal to the length of the current path between the second semiconductor light emitting element 30B and the second switching element 412. This reduces the variation in the length of the loop-shaped first current path formed by the first semiconductor light emitting element 30A, the first switching element 411, and the first capacitor 421, and the length of the loop-shaped second current path formed by the second semiconductor light emitting element 30B, the second switching element 412, and the second capacitor 422.

[0107] (1-5) A plurality of first capacitors 421 and a plurality of second capacitors 422 are provided. The plurality of first capacitors 421 are connected in parallel with one another. The plurality of second capacitors 422 are connected in parallel with one another.

[0108] According to this configuration, since the multiple first capacitors 421 are connected in parallel with each other, the total inductance of the multiple first capacitors 421 can be reduced below the inductance of each of the first capacitors 421. Furthermore, since the multiple second capacitors 422 are connected in parallel with each other, the total inductance of the multiple second capacitors 422 can be reduced below the inductance of each of the second capacitors 422.

[0109] (1-6) The multiple first capacitors 421 are arranged spaced apart from one another in the X direction. The multiple second capacitors 422 are arranged spaced apart from one another in the X direction. With this configuration, the arrangement direction (X direction) of the multiple first capacitors 421 is orthogonal to the arrangement direction (Y direction) of the first semiconductor light emitting element 30A, the first switching element 411, and the first capacitor 421 in a planar view. Therefore, the length of the loop-shaped first current path formed by the first semiconductor light emitting element 30A, the first switching element 411, and the first capacitor 421 can be shortened. The arrangement direction (X direction) of the multiple second capacitors 422 is orthogonal to the arrangement direction (Y direction) of the second semiconductor light emitting element 30B, the second switching element 412, and the second capacitor 422 in a planar view. Therefore, the length of the loop-shaped second current path formed by the second semiconductor light emitting element 30B, the second switching element 412, and the second capacitor 422 can be shortened.

[0110] (1-7) The semiconductor light emitting device further includes a first protection diode 50A connected in anti-parallel to the first semiconductor light emitting element 30A, and a second protection diode 50B connected in anti-parallel to the second semiconductor light emitting element 30B.

[0111] With this configuration, the first protection diode 50A and the second protection diode 50B can prevent the resonant current from applying an excessive reverse bias to the first semiconductor light emitting element 30A and the second semiconductor light emitting element 30B, thereby increasing the peak optical output of each of the first semiconductor light emitting element 30A and the second semiconductor light emitting element 30B.

[0112] (1-8) The first protection diode 50A is arranged on the opposite side of the first semiconductor light emitting element 30A with respect to the first switching element 411 in the Y direction. The second protection diode 50B is arranged on the opposite side of the second semiconductor light emitting element 30B with respect to the second switching element 412 in the Y direction. The first protection diode 50A is arranged to be spaced apart from the first capacitor 421 in the Y direction. The second protection diode 50B is arranged to be spaced apart from the second capacitor 422 in the Y direction.

[0113] According to this configuration, the length of the loop-shaped first current path formed by the first semiconductor light emitting element 30A, the first switching element 411, and the first capacitor 421 can be shortened compared to a configuration in which the first protection diode 50A is arranged between the first semiconductor light emitting element 30A and the first switching element 411 or between the first switching element 411 and the first capacitor 421. Furthermore, the length of the loop-shaped second current path formed by the second semiconductor light emitting element 30B, the second switching element 412, and the second capacitor 422 can be shortened compared to a configuration in which the second protection diode 50B is arranged between the second semiconductor light emitting element 30B and the second switching element 412 or between the second switching element 412 and the second capacitor 422.

[0114] (1-9) In plan view, the area of ​​the first back surface electrodes 71A, 71B is larger than the area of ​​each of the second back surface electrodes 72A, 72B, the third back surface electrodes 73A, 73B, and the fourth back surface electrodes 74A, 74B.

[0115] According to this configuration, the heat capacity of the first back-surface electrode 71A is increased, so that heat from the first semiconductor light-emitting element 30A is more likely to transfer to the first back-surface electrode 71A. The heat capacity of the first back-surface electrode 71B is increased, so that heat from the second semiconductor light-emitting element 30B is more likely to transfer to the first back-surface electrode 71B. In addition, when the semiconductor light-emitting device 10 is mounted on a circuit board 900, the bonding area between the first back-surface electrodes 71A, 71B and the circuit board 900 is increased, so that heat from each of the first semiconductor light-emitting element 30A and the second semiconductor light-emitting element 30B is more likely to transfer to the circuit board 900 via the first back-surface electrodes 71A, 71B. Therefore, it is possible to prevent the temperatures of each of the first semiconductor light-emitting element 30A and the second semiconductor light-emitting element 30B from becoming excessively high.

[0116] (1-12) In plan view, the area of ​​the first back surface electrode 71A is larger than the sum of the areas of the second back surface electrode 72A, the third back surface electrode 73A, and the fourth back surface electrode 74A. In plan view, the area of ​​the first back surface electrode 71B is larger than the sum of the areas of the second back surface electrode 72B, the third back surface electrode 73B, and the fourth back surface electrode 74B.

[0117] With this configuration, the heat capacity of the first back-surface electrodes 71A, 71B is increased, making it easier for heat from each of the first semiconductor light emitting element 30A and the second semiconductor light emitting element 30B to transfer to the first back-surface electrodes 71A, 71B. In addition, when the semiconductor light emitting device 10 is mounted on the circuit board 900, the bonding area between the first back-surface electrodes 71A, 71B and the circuit board 900 is increased, making it easier for heat from each of the first semiconductor light emitting element 30A and the second semiconductor light emitting element 30B to transfer to the circuit board 900 via the first back-surface electrodes 71A, 71B. This makes it possible to further prevent the temperature of each of the first semiconductor light emitting element 30A and the second semiconductor light emitting element 30B from becoming excessively high.

[0118] (1-13) In plan view, the area of ​​the first intermediate electrodes 81A and 81B 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.

[0119] With this configuration, the heat capacity of the first intermediate electrode 81A is increased, making it easier for heat from the first semiconductor light emitting element 30A to move to the first intermediate electrode 81A. This makes it possible to prevent the temperature of the first semiconductor light emitting element 30A from becoming excessively high. The heat capacity of the first intermediate electrode 81B is increased, making it easier for heat from the second semiconductor light emitting element 30B to move to the first intermediate electrode 81B. This makes it possible to prevent the temperature of the second semiconductor light emitting element 30B from becoming excessively high.

[0120] (1-13) In a plan view, the area of ​​the first intermediate electrode 81A is larger than the combined area of ​​the second intermediate electrode 82A, the third intermediate electrode 83A, and the fourth intermediate electrode 84A. In a plan view, the area of ​​the first intermediate electrode 81B is larger than the combined area of ​​the second intermediate electrode 82B, the third intermediate electrode 83B, and the fourth intermediate electrode 84B.

[0121] With this configuration, the heat capacity of the first intermediate electrodes 81A, 81B is increased, which makes it easier for heat from each of the first semiconductor light emitting element 30A and the second semiconductor light emitting element 30B to move to the first intermediate electrodes 81A, 81B, thereby further preventing the temperature of each of the first semiconductor light emitting element 30A and the second semiconductor light emitting element 30B from becoming excessively high.

[0122] (1-14) The plurality of first vias 91A are arranged at positions overlapping the first semiconductor light emitting element 30A in plan view. The plurality of first vias 91B are arranged at positions overlapping the second semiconductor light emitting element 30B in plan view.

[0123] According to this configuration, heat from the first semiconductor light emitting element 30A is more likely to transfer to the first intermediate electrode 81A and the first back surface electrode 71A. Heat from the second semiconductor light emitting element 30B is more likely to transfer to the first intermediate electrode 81B and the first back surface electrode 71B. As a result, the temperatures of the first semiconductor light emitting element 30A and the second semiconductor light emitting element 30B can be prevented from becoming excessively high.

[0124] (1-15) The second surface electrode 62A includes a narrow portion 62AA and a wide portion 62AB. A first switching element 411 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, like the second surface electrode 62A, includes a narrow portion and a wide portion. A second switching element 412 is mounted on this narrow portion. Both the third surface electrode 63B and the fourth surface electrode 64B include a portion located adjacent to the narrow portion of the second surface electrode 62B in the X direction.

[0125] This configuration makes it possible to shorten the lengths of the wire W2 connecting the source electrode 41S and the fourth surface electrode 64A of the first switching element 411 and the wire W3 connecting the gate electrode 41G and the third surface electrode 63A of the first switching element 411. Also, it is possible to shorten the lengths of the wire W2 connecting the source electrode 41S and the fourth surface electrode 64B of the second switching element 412 and the wire W3 connecting the gate electrode 41G and the third surface electrode 63B of the second switching element 412.

[0126] (1-16) The first switching element 411 is disposed at a position overlapping the first semiconductor light emitting element 30A when viewed from the Y direction. The second switching element 412 is disposed at a position overlapping the second semiconductor light emitting element 30B when viewed from the Y direction.

[0127] With this configuration, the distance between the first switching element 411 and the first semiconductor light emitting element 30A can be shortened compared to a configuration in which the first switching element 411 is disposed at a position offset in the X direction with respect to the first semiconductor light emitting element 30A. Therefore, when the source electrode 41S of the first switching element 411 and the element surface electrode 34 of the first semiconductor light emitting element 30A 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 412 is disposed at a position offset in the X direction with respect to the second semiconductor light emitting element 30B, the distance between the second switching element 412 and the second semiconductor light emitting element 30B can be shortened. Therefore, when the source electrode 41S of the second switching element 412 and the element surface electrode 34 of the second semiconductor light emitting element 30B are connected by a wire W1, the length of the wire W1 can be shortened.

[0128] (1-17) Vertical transistors of the same configuration are used for the first switching element 411 and the second switching element 412. 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.

[0129] 9 to 13, 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 semiconductor light emitting elements. Below, differences from the first embodiment will be described in detail, and components common to the first embodiment will be assigned the same reference numerals, and their description may be omitted.

[0130] FIG. 9 shows a schematic planar structure of a semiconductor light-emitting device 10 of the second embodiment. FIG. 10 shows a schematic planar structure of an enlarged portion of the semiconductor light-emitting device 10 of FIG. 9 between the imaginary center line VC and the first substrate side surface 23. FIG. 11 shows a schematic back surface structure of the semiconductor light-emitting device 10 of FIG. 9. FIG. 12 shows a schematic planar structure of a front-side intermediate electrode 28C of the semiconductor light-emitting device 10 of FIG. 9. FIG. 13 shows a schematic circuit configuration of a light-emitting system 800 including the semiconductor light-emitting device 10 of the second embodiment. Note that in FIGS. 9 and 10, openings in the front-surface resist 29A are indicated by two-dot chain lines. In FIG. 11, openings in the back-surface resist 29B are indicated by two-dot chain lines.

[0131] 9, the semiconductor light emitting device 10 of the second embodiment includes four semiconductor light emitting elements, namely, first to fourth semiconductor light emitting elements 30A to 30D. The first to fourth semiconductor light emitting elements 30A to 30D have the same configuration. Each of the first to fourth semiconductor light emitting elements 30A to 30D includes two semiconductor light emitting elements.

[0132] The semiconductor light emitting device 10 includes a configuration for individually controlling the driving of the first to fourth semiconductor light emitting elements 30A to 30D. More specifically, the semiconductor light emitting device 10 includes a first drive circuit 40A that drives the first semiconductor light emitting element 30A, a second drive circuit 40B that drives the second semiconductor light emitting element 30B, a third drive circuit 40C that drives the third semiconductor light emitting element 30C, and a fourth drive circuit 40D that drives the fourth semiconductor light emitting element 30D.

[0133] The first drive circuit 40A is electrically connected to the element surface electrode 34 of the first semiconductor light emitting element 30A. The second drive circuit 40B is electrically connected to the element surface electrode 34 of the second semiconductor light emitting element 30B. The third drive circuit 40C is electrically connected to the element surface electrode 34 of the third semiconductor light emitting element 30C. The fourth drive circuit 40D is electrically connected to the element surface electrode 34 of the fourth semiconductor light emitting element 30D.

[0134] As in the first embodiment, the first drive circuit 40A includes a first switching element 411 and a first capacitor 421. As in the first embodiment, the second drive circuit 40B includes a second switching element 412 and a second capacitor 422.

[0135] The third drive circuit 40C includes a third switching element 413 that controls the drive of the third semiconductor light emitting element 30C, and a third capacitor 423 that supplies current to the third semiconductor light emitting element 30C. The fourth drive circuit 40D includes a fourth switching element 414 that controls the drive of the fourth semiconductor light emitting element 30D, and a fourth capacitor 424 that supplies current to the fourth semiconductor light emitting element 30D.

[0136] The first to fourth capacitors 421 to 424 have the same configuration. The first switching element 411 and the fourth switching element 414 have the same structure. The second switching element 412 and the third switching element 413 have the same configuration. On the other hand, the structure of the first switching element 411 and the fourth switching element 414 is different from the structure of the second switching element 412 and the third switching element 413. Specifically, the positions of the gate electrodes 41G of the first switching element 411 and the fourth switching element 414 and the second switching element 412 and the third switching element 413 are different from each other.

[0137] The first switching element 411 is configured to control driving of the first semiconductor light emitting element 30A. The first capacitor 421 is configured to supply current to the first semiconductor light emitting element 30A. The first switching element 411 and the first capacitor 421 are arranged apart from the first semiconductor light emitting element 30A in a plan view.

[0138] The second switching element 412 is configured to control the driving of the second semiconductor light emitting element 30B. The second capacitor 422 is configured to supply current to the second semiconductor light emitting element 30B. The second switching element 412 and the second capacitor 422 are arranged apart from the second semiconductor light emitting element 30B in a plan view.

[0139] The third switching element 413 is configured to control driving of the third semiconductor light emitting element 30C. The third capacitor 423 is configured to supply current to the third semiconductor light emitting element 30C. The third switching element 413 and the third capacitor 423 are arranged apart from the third semiconductor light emitting element 30C in a plan view.

[0140] The fourth switching element 414 is configured to control driving of the fourth semiconductor light emitting element 30D. The fourth capacitor 424 is configured to supply current to the fourth semiconductor light emitting element 30D. The fourth switching element 414 and the fourth capacitor 424 are arranged apart from the fourth semiconductor light emitting element 30D in a plan view. In the second embodiment, ceramic capacitors are used for the first to fourth capacitors 421 to 424, as in the first embodiment.

[0141] 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 of the second embodiment, particularly the front electrode 28A, the back electrode 28B, and the front-side intermediate electrode 28C, as well as the connection structure between these electrodes, will be described below. Note that the back-side intermediate electrode 28D has the same configuration as the front-side intermediate electrode 28C, and therefore its description will be omitted.

[0142] (Surface Electrodes) The substrate 20 includes, as surface electrodes 28A formed on the substrate surface 21, first surface electrodes 101A to 101D, second surface electrodes 102A to 102D, third surface electrodes 103A to 103D, fourth surface electrodes 104A and 104B, and fifth surface electrodes 105A to 105D, which are arranged at a distance from one another.

[0143] 9 , the first surface electrodes 101A and 101C, the second surface electrodes 102A and 102C, the third surface electrodes 103A and 103C, the fourth surface electrode 104A, and the fifth surface electrodes 105A and 105C are arranged closer to the first substrate side surface 23 than the imaginary center line VC. The first surface electrodes 101B and 101D, the second surface electrodes 102B and 102D, the third surface electrodes 103B and 103D, the fourth surface electrode 104B, and the fifth surface electrodes 105B and 105D are arranged closer to the second substrate side surface 24 than the imaginary center line VC. The first surface electrodes 101A, 101C, the second surface electrodes 102A, 102C, the third surface electrodes 103A, 103C, the fourth surface electrode 104A, and the fifth surface electrodes 105A, 105C are symmetrical with the first surface electrodes 101B, 101D, the second surface electrodes 102B, 102D, the third surface electrodes 103B, 103D, the fourth surface electrode 104B, and the fifth surface electrodes 105B, 105D with respect to the virtual center line VC. For this reason, in the following, with reference to Figure 10, the first surface electrodes 101A, 101C, the second surface electrodes 102A, 102C, the third surface electrodes 103A, 103C, the fourth surface electrode 104A, and the fifth surface electrodes 105A, 105C will be described in detail, and a detailed description of the first surface electrodes 101B, 101D, the second surface electrodes 102B, 102D, the third surface electrodes 103B, 103D, the fourth surface electrode 104B, and the fifth surface electrodes 105B, 105D will be omitted.

[0144] 10 , the first surface electrode 101A is an electrode on which the first semiconductor light emitting element 30A is mounted, and the first surface electrode 101C is an electrode on which the third semiconductor light emitting element 30C is mounted. The first surface electrodes 101A and 101C are arranged in a position adjacent to the third substrate side surface 25 in the Y direction. The first surface electrodes 101A and 101C are arranged in the X direction closer to the virtual center line VC than the center in the X direction between the virtual center line VC and the first substrate side surface 23. The first surface electrodes 101A and 101C are arranged side by side in the X direction. The first surface electrode 101A is arranged closer to the virtual center line VC than the first surface electrode 101C. The first surface electrode 101A is arranged in a position adjacent to the virtual center line VC in the X direction. The first surface electrodes 101A and 101C have the same shape and size. The first surface electrodes 101A and 101C are 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.

[0145] The second to fifth surface electrodes 102A, 103A, 104A, and 105A are electrodes on which the first drive circuit 40A is mounted, and the second to fifth surface electrodes 102C, 103C, 104A, and 105C are electrodes on which the third drive circuit 40C is mounted. The fourth surface electrode 104A is an electrode to which both the first drive circuit 40A and the third drive circuit 40C are electrically connected.

[0146] The second to fifth surface electrodes 102A to 105A are arranged closer to the fourth substrate side surface 26 in the Y direction than the first surface electrodes 101A and 101C. The second surface electrode 102A is arranged in a position adjacent to the first surface electrode 101A in the Y direction. The second surface electrode 102A is arranged in a position overlapping with the first surface electrodes 101A and 101C when viewed from the Y direction. In one example, the second surface electrode 102A is arranged in a position adjacent to the imaginary center line VC in the X direction.

[0147] The second surface electrode 102A is an electrode on which the first switching element 411 is mounted. The second surface electrode 102A includes a narrow portion, a wide portion whose dimension in the X direction is larger than that of the narrow portion, and a connecting portion. The narrow portion and wide portion of the second surface electrode 102A 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. The narrow portion is located closer to the imaginary center line VC than the first surface electrode 101C in the X direction. The wide portion is located at a position overlapping with the first surface electrode 101C when viewed from the Y direction. The narrow portion is located at a position adjacent to the first surface electrode 101A in the Y direction.

[0148] The third surface electrode 103A is an electrode electrically connected to the gate electrode 41G of the first switching element 411. The third surface electrode 103A is disposed in a position adjacent to the connecting portion of the second surface electrode 102A in the X direction. The third surface electrode 103A is disposed in a position overlapping with the first surface electrode 101C when viewed from the Y direction.

[0149] The fifth surface electrode 105A is an electrode on which the first capacitor 421 is mounted. The fifth surface electrode 105A is arranged closer to the fourth substrate side surface 26 than the second surface electrode 102A in the Y direction. The fifth surface electrode 105A is arranged in a position adjacent to the wide portion of the second surface electrode 102A in the Y direction. The fifth surface electrode 105A is formed in a rectangular shape with the longitudinal direction being the X direction and the lateral direction being the Y direction in a plan view.

[0150] The second surface electrode 102C, the third surface electrode 103C, and the fifth surface electrode 105C are arranged closer to the first substrate side surface 23 in the X direction than the first surface electrodes 101A and 101C. In one example, the second surface electrode 102C, the third surface electrode 103C, and the fifth surface electrode 105C are arranged closer to the first substrate side surface 23 in the X direction than the second to fifth surface electrodes 102A to 105A. The second surface electrode 102C, the third surface electrode 103C, and the fifth surface electrode 105C are arranged so as to overlap with the narrow portion of the second surface electrode 102A when viewed from the X direction.

[0151] The second surface electrode 102C is an electrode on which the third switching element 413 is mounted. The third surface electrode 103C includes a narrow portion, a wide portion that is larger in the Y direction than the narrow portion, and a connecting portion. The narrow portion and wide portion of the third surface electrode 103C are arranged spaced apart in the X direction. The connecting portion connects the narrow portion and the wide portion between them in the X direction. The narrow portion is located adjacent to the first surface electrode 101C in the X direction. The wide portion is located closer to the first substrate side surface 23 than the narrow portion.

[0152] The third surface electrode 103C is an electrode electrically connected to the gate electrode 41G of the third switching element 413. The third surface electrode 103C is disposed in a position adjacent to the connecting portion of the second surface electrode 102C in the Y direction. The third surface electrode 103C is disposed closer to the fourth substrate side surface 26 in the Y direction than the connecting portion of the second surface electrode 102C.

[0153] The fifth surface electrode 105C is an electrode on which the third capacitor 423 is mounted. The fifth surface electrode 105C is arranged closer to the first substrate side surface 23 in the X direction than the second surface electrode 102C. The fifth surface electrode 105C is arranged in a position adjacent to the wide portion of the second surface electrode 102C in the X direction. The fifth surface electrode 105C is formed in a rectangular shape with its short side extending in the X direction and its long side extending in the Y direction in a plan view.

[0154] The fourth surface electrode 104A is an electrode common to the first drive circuit 40A and the third drive circuit 40C. The fourth surface electrode 104A is formed on the substrate surface 21 between the second, third, and fifth surface electrodes 102A, 103A, and 105A and the second, third, and fifth surface electrodes 102C, 103C, and 105C. In a plan view, the area of ​​the fourth surface electrode 104A is larger than the area of ​​each of the second, third, and fifth surface electrodes 102A, 103A, and 105A. In a plan view, the area of ​​the fourth surface electrode 104A is larger than the combined area of ​​the second, third, and fifth surface electrodes 102A, 103A, and 105A.

[0155] 11 , the substrate 20 includes first back-surface electrodes 111A to 111D, second back-surface electrodes 112A to 112D, third back-surface electrodes 113A to 113D, and fourth back-surface electrodes 114A and 114B that are arranged apart from one another as a back-surface electrode 28B formed on the substrate back surface 22. The first back-surface electrodes 111A to 111D, second back-surface electrodes 112A to 112D, third back-surface electrodes 113A to 113D, and fourth back-surface electrodes 114A and 114B constitute external electrode terminals that are electrically connected to a circuit board 900 (see FIG. 7 ) when the semiconductor light-emitting device 10 is mounted on the circuit board 900.

[0156] The first back surface electrode 111A, the second back surface electrode 112A, the third back surface electrode 113A, and the fourth back surface electrode 114A are electrodes electrically connected to the first driving circuit 40A. The first back surface electrode 111C, the second back surface electrode 112C, the third back surface electrode 113C, and the fourth back surface electrode 114A are electrodes electrically connected to the third driving circuit 40C. The fourth back surface electrode 114A is an electrode electrically connected to both the first driving circuit 40A and the third driving circuit 40C.

[0157] The first back surface electrode 111B, the second back surface electrode 112B, the third back surface electrode 113B, and the fourth back surface electrode 114B are electrodes electrically connected to the second driving circuit 40B. The first back surface electrode 111D, the second back surface electrode 112D, the third back surface electrode 113D, and the fourth back surface electrode 114B are electrodes electrically connected to the fourth driving circuit 40D. The fourth back surface electrode 114B is an electrode electrically connected to both the second driving circuit 40B and the fourth driving circuit 40D.

[0158] 11 , the first back-surface electrodes 111A and 111C, the second back-surface electrodes 112A and 112C, the third back-surface electrodes 113A and 113C, and the fourth back-surface electrode 114A are arranged closer to the first substrate side surface 23 than the imaginary center line VC. The first back-surface electrodes 111B and 111D, the second back-surface electrodes 112B and 112D, the third back-surface electrodes 113B and 113D, and the fourth back-surface electrode 114B are arranged closer to the second substrate side surface 24 than the imaginary center line VC. The first back-surface electrodes 111A and 111C, the second back-surface electrodes 112A and 112C, the third back-surface electrodes 113A and 113C, and the fourth back-surface electrode 114A are symmetrical with the first back-surface electrodes 111B and 111D, the second back-surface electrodes 112B and 112D, the third back-surface electrodes 113B and 113D, and the fourth back-surface electrode 114B about the virtual center line VC. Therefore, hereinafter, the first back-surface electrodes 111A and 111C, the second back-surface electrodes 112A and 112C, the third back-surface electrodes 113A and 113C, and the fourth back-surface electrode 114A will be described in detail with reference to FIG. 11 , and a detailed description of the first back-surface electrodes 111B and 111D, the second back-surface electrodes 112B and 112D, the third back-surface electrodes 113B and 113D, and the fourth back-surface electrode 114B will be omitted.

[0159] The first back surface electrode 111A is an electrode electrically connected to the first surface electrode 101A and the fifth surface electrode 105A (see FIG. 10 for both). The first back surface electrode 111A is disposed adjacent to the imaginary center line VC in the X direction. The first back surface electrode 111A is formed in a strip shape extending in the Y direction. The first back surface electrode 111A is disposed so as to overlap both the first surface electrode 101A and the fifth surface electrode 105A in a plan view.

[0160] The second back surface electrode 112A is an electrode electrically connected to the second surface electrode 102A (see FIG. 10 ). The second back surface electrode 112A is arranged closer to the first substrate side surface 23 than the first back surface electrode 111A. The second back surface electrode 112A is arranged adjacent to the first back surface electrode 111A in the X direction. The second back surface electrode 112A has a strip shape extending in the Y direction. The dimension of the second back surface electrode 112A in the Y direction is smaller than the dimension of the first back surface electrode 111A in the Y direction. The second back surface electrode 112A includes a portion that overlaps with the wide portion of the second surface electrode 102A in a plan view.

[0161] The third back surface electrode 113A is an electrode electrically connected to the third surface electrode 103A (see FIG. 10 ). The third back surface electrode 113A is arranged closer to the first substrate side surface 23 than the second back surface electrode 112A. The third back surface electrode 113A is arranged in a position adjacent to the second back surface electrode 112A. The third back surface electrode 113A includes a portion overlapping with the second back surface electrode 112A when viewed from the Y direction. The third back surface electrode 113A includes a portion overlapping with the third surface electrode 103A in a plan view.

[0162] The first back surface electrode 111C is an electrode electrically connected to the first surface electrode 101C and the fifth surface electrode 105C (see FIG. 10 for both). The first back surface electrode 111C is arranged closer to the first substrate side surface 23 in the X direction than the first back surface electrode 111A. The first back surface electrode 111C is arranged in a position adjacent to the first back surface electrode 111A in the X direction. The first back surface electrode 111C has a strip shape extending in the X direction. The first back surface electrode 111C includes portions that overlap with both the first surface electrode 101C and the fifth surface electrode 105C in a plan view.

[0163] The second back surface electrode 112C is an electrode electrically connected to the second surface electrode 102C (see FIG. 10 ). The second back surface electrode 112C is arranged closer to the fourth substrate side surface 26 than the first back surface electrode 111C. The second back surface electrode 112C is arranged adjacent to the first back surface electrode 111C in the Y direction. The second back surface electrode 112C has a strip shape extending in the X direction. In one example, the dimension of the second back surface electrode 112C in the X direction is equal to the dimension of the second back surface electrode 112A in the Y direction. The second back surface electrode 112C includes a portion that overlaps with the wide portion of the second surface electrode 102C in a plan view.

[0164] The third back surface electrode 113C is an electrode electrically connected to the third surface electrode 103C (see FIG. 10 ). The third back surface electrode 113C is arranged closer to the fourth substrate side surface 26 than the third back surface electrode 113C. The third back surface electrode 113C is arranged in a position adjacent to the second back surface electrode 112C. The third back surface electrode 113C includes a portion that overlaps with the second back surface electrode 112C when viewed from the X direction. The overlapping portion of the third back surface electrode 113C is arranged in a position that overlaps with the third surface electrode 103C in a plan view.

[0165] The fourth back surface electrode 114A is an electrode electrically connected to the fourth surface electrode 104A (see FIG. 10 ). The fourth back surface electrode 114A is formed in a region surrounded by the third back surface electrodes 113A and 113C, the first substrate side surface 23, and the fourth substrate side surface 26. The fourth back surface electrode 114A is formed in a rectangular shape with its longitudinal direction in the X direction and its lateral direction in the Y direction. The fourth back surface electrode 114A includes a portion that overlaps with the fourth surface electrode 104A in a plan view.

[0166] The first back surface electrode 111B is an electrode electrically connected to both the first front surface electrode 101B and the fifth front surface electrode 105B (see FIG. 9 ). The second back surface electrode 112B is an electrode electrically connected to the second front surface electrode 102B (see FIG. 9 ). The third back surface electrode 113B is an electrode electrically connected to the third front surface electrode 103B (see FIG. 9 ).

[0167] The first back surface electrode 111D is an electrode electrically connected to both the first surface electrode 101D and the fifth surface electrode 105D (see FIG. 9). The second back surface electrode 112D is an electrode electrically connected to the second surface electrode 102D (see FIG. 9). The third back surface electrode 113D is an electrode electrically connected to the third surface electrode 103D (see FIG. 9). The fourth back surface electrode 114B is an electrode electrically connected to the fourth surface electrode 104B (see FIG. 9).

[0168] (Surface-side intermediate electrode) As shown in Figure 12, the substrate 20 includes first intermediate electrodes 121A to 121D, second intermediate electrodes 122A to 122D, third intermediate electrodes 123A to 123D, and fourth intermediate electrodes 124A and 124B arranged at a distance from each other as a surface-side intermediate electrode 28C formed on the substrate surface of the intermediate substrate 27C.

[0169] 12 , the first intermediate electrodes 121A and 121C, the second intermediate electrodes 122A and 122C, the third intermediate electrodes 123A and 123C, and the fourth intermediate electrode 124A are arranged closer to the first substrate side surface 23 than the imaginary center line VC. The first intermediate electrodes 121B and 121D, the second intermediate electrodes 122B and 122D, the third intermediate electrodes 123B and 123D, and the fourth intermediate electrode 124B are arranged closer to the second substrate side surface 24 than the imaginary center line VC. The first intermediate electrodes 121A and 121C, the second intermediate electrodes 122A and 122C, the third intermediate electrodes 123A and 123C, and the fourth intermediate electrode 124A are symmetrical with the first intermediate electrodes 121B and 121D, the second intermediate electrodes 122B and 122D, the third intermediate electrodes 123B and 123D, and the fourth intermediate electrode 124B about the virtual center line VC. Therefore, hereinafter, the first intermediate electrodes 121A and 121C, the second intermediate electrodes 122A and 122C, the third intermediate electrodes 123A and 123C, and the fourth intermediate electrode 124A will be described in detail with reference to FIG. 12 , and detailed descriptions of the first intermediate electrodes 121B and 121D, the second intermediate electrodes 122B and 122D, the third intermediate electrodes 123B and 123D, and the fourth intermediate electrode 124B will be omitted.

[0170] The first intermediate electrode 121A is an electrode that electrically connects the first surface electrode 101A and the fifth surface electrode 105A (see FIG. 10 ) to the first back surface electrode 111A. The first intermediate electrode 121A is disposed adjacent to the imaginary center line VC in the X direction. In a plan view, the area of ​​the first intermediate electrode 121A is larger than the area of ​​the first back surface electrode 111A. In one example, the Y direction dimension of the first intermediate electrode 121A is equal to the Y direction dimension of the first back surface electrode 111A, and includes a portion where the X direction dimension of the first intermediate electrode 121A is larger than the X direction dimension of the first back surface electrode 111A. The first intermediate electrode 121A includes portions that overlap with the first surface electrode 101A, the fifth surface electrode 105A, and the first back surface electrode 111A in a plan view.

[0171] The first intermediate electrode 121A has a first oval opening and a second circular opening. Both the first opening and the second opening are located closer to the first substrate side surface 23 than the first surface electrode 101A (see FIG. 10 ) in a plan view. In other words, neither the first opening nor the second opening is formed between a first via 131A and a fifth via 135A (described later) in the Y direction, and the first intermediate electrode 121A extends along the Y direction.

[0172] The second intermediate electrode 122A is disposed within the first opening. The second intermediate electrode 122A is an electrode electrically connected to both the second front surface electrode 102A (see FIG. 10 ) and the second rear surface electrode 112A (see FIG. 11 ). The second intermediate electrode 122A is formed in an oval shape that is slightly smaller than the first opening. The second intermediate electrode 122A is disposed at a position that overlaps both the second front surface electrode 102A and the second rear surface electrode 112A in a plan view.

[0173] The third intermediate electrode 123A is disposed within the second opening. The third intermediate electrode 123A is an electrode electrically connected to both the third surface electrode 103A (see FIG. 10 ) and the third back surface electrode 113A (see FIG. 11 ). The third intermediate electrode 123A is formed in a circular shape that is slightly smaller than the second opening. The third intermediate electrode 123A is disposed at a position that overlaps both the third surface electrode 103A and the third back surface electrode 113A in a plan view.

[0174] The first intermediate electrode 121C is an electrode that electrically connects the first surface electrode 101C and the fifth surface electrode 105C (both see FIG. 10 ) to the first back surface electrode 111C. The first intermediate electrode 121C is disposed adjacent to the third substrate side surface 25 in the Y direction. In a plan view, the area of ​​the first intermediate electrode 121C is larger than the area of ​​the first back surface electrode 111C. In one example, the X-direction dimension of the first intermediate electrode 121C is equal to the X-direction dimension of the first back surface electrode 111C, and includes a portion where the Y-direction dimension of the first intermediate electrode 121C is larger than the Y-direction dimension of the first back surface electrode 111C. The first intermediate electrode 121C includes portions that overlap with the first surface electrode 101C, the fifth surface electrode 105C, and the first back surface electrode 111C in a plan view.

[0175] The first intermediate electrode 121C has a first oval opening and a second circular opening. Both the first opening and the second opening are located closer to the fourth substrate side surface 26 than the first surface electrode 101C (see FIG. 10 ) in a plan view. In other words, neither the first opening nor the second opening is formed between a first via 131C and a fifth via 135C (described later) in the X direction, and the first intermediate electrode 121C extends along the X direction.

[0176] The second intermediate electrode 122C is disposed within the first opening. The second intermediate electrode 122C is an electrode electrically connected to both the second front surface electrode 102C (see FIG. 10 ) and the second rear surface electrode 112C (see FIG. 11 ). The second intermediate electrode 122C is formed in an oval shape that is slightly smaller than the first opening. The second intermediate electrode 122C is disposed at a position overlapping both the fourth front surface electrode 104A and the fourth rear surface electrode 114A in a plan view.

[0177] The third intermediate electrode 123C is disposed within the second opening. The third intermediate electrode 123C is an electrode electrically connected to both the third surface electrode 103C (see FIG. 10 ) and the third back surface electrode 113C (see FIG. 11 ). The third intermediate electrode 123C is formed in a circular shape that is slightly smaller than the second opening. The third intermediate electrode 123C is disposed at a position that overlaps both the third surface electrode 103C and the third back surface electrode 113C in a plan view.

[0178] The first intermediate electrode 121B electrically connects the first surface electrode 101B and the fifth surface electrode 105B (see FIG. 9 ) to the first back surface electrode 111B (see FIG. 11 ). The second intermediate electrode 122B electrically connects the second surface electrode 102B (see FIG. 9 ) to the second back surface electrode 112B (see FIG. 11 ). The third intermediate electrode 123B electrically connects the third surface electrode 103B (see FIG. 9 ) to the third back surface electrode 113B (see FIG. 11 ).

[0179] The first intermediate electrode 121D is an electrode that electrically connects the first surface electrode 101D and the fifth surface electrode 105D (both see FIG. 10 ) with the first back surface electrode 111D (see FIG. 11 ). The second intermediate electrode 122D is an electrode that electrically connects the second surface electrode 102D (see FIG. 9 ) with the second back surface electrode 112D (see FIG. 11 ). The third intermediate electrode 123D is an electrode that electrically connects the third surface electrode 103D (see FIG. 9 ) with the third back surface electrode 113D (see FIG. 11 ). The fourth intermediate electrode 124B is an electrode that electrically connects the fourth surface electrode 104B (see FIG. 9 ) with the fourth back surface electrode 114B (see FIG. 11 ).

[0180] 10 to 12 , the substrate 20 includes first vias 131A to 131D, second vias 132A to 132D, third vias 133A to 133D, fourth vias 134A and 134B, and fifth vias 135A to 135D. The first vias 131A to 131D, second vias 132A to 132D, third vias 133A to 133D, fourth vias 134A and 134B, and fifth vias 135A to 135D 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 131A to 131D, the second vias 132A to 132D, the third vias 133A to 133D, the fourth vias 134A and 134B, and the fifth vias 135A to 135D are formed from a material containing one or more appropriately selected from the group consisting of Ti, TiN, Au, Ag, Cu, Al, and W.

[0181] 10 to 12, the first vias 131A and 131C, the second vias 132A and 132C, the third vias 133A and 133C, the fourth via 134A, and the fifth vias 135A and 135C are arranged closer to the first substrate side surface 23 than the imaginary center line VC. The first vias 131B and 131D, the second vias 132B and 132D, the third vias 133B and 133D, the fourth via 134B, and the fifth vias 135B and 135D are arranged closer to the second substrate side surface 24 than the imaginary center line VC. The first vias 131A, 131C, the second vias 132A, 132C, the third vias 133A, 133C, the fourth via 134A, and the fifth vias 135A, 135C are symmetrical with the first vias 131B, 131D, the second vias 132B, 132D, the third vias 133B, 133D, the fourth via 134B, and the fifth vias 135B, 135D with respect to the virtual center line VC. For this reason, in the following, with reference to Figures 10 to 12, the first vias 131A, 131C, the second vias 132A, 132C, the third vias 133A, 133C, the fourth via 134A, and the fifth vias 135A, 135C will be described in detail, and detailed descriptions of the first vias 131B, 131D, the second vias 132B, 132D, the third vias 133B, 133D, the fourth via 134B, and the fifth vias 135B, 135D will be omitted.

[0182] A plurality of first vias 131A are provided. The plurality of first vias 131A connect the first surface electrode 101A, the first back surface electrode 111A, and the first intermediate electrodes 121A of the surface-side intermediate electrode 28C and the back-side intermediate electrode 28D. This electrically connects the first surface electrode 101A, the first back surface electrode 111A, and the first intermediate electrodes 121A of the surface-side intermediate electrode 28C and the back-side intermediate electrode 28D to one another.

[0183] A plurality of first vias 131C are provided. The plurality of first vias 131C connect the first surface electrode 101C, the first back surface electrode 111C, and the first intermediate electrodes 121C of the surface-side intermediate electrode 28C and the back-side intermediate electrode 28D. This electrically connects the first surface electrode 101C, the first back surface electrode 111C, and the first intermediate electrodes 121C of the surface-side intermediate electrode 28C and the back-side intermediate electrode 28D to one another.

[0184] A plurality of second vias 132A are provided. The second vias 132A connect the wide portion of the second surface electrode 102A, the second back surface electrode 112A, and the second intermediate electrodes 122A of the surface-side intermediate electrode 28C and the back surface-side intermediate electrode 28D. This electrically connects the second surface electrode 102A, the second back surface electrode 112A, and the second intermediate electrodes 122A of the surface-side intermediate electrode 28C and the back surface-side intermediate electrode 28D to one another.

[0185] The third via 133A connects the third surface electrode 103A, the third back surface electrode 113A, and the third intermediate electrodes 123A of the surface-side intermediate electrode 28C and the back-side intermediate electrode 28D, thereby electrically connecting the third surface electrode 103A, the third back surface electrode 113A, and the third intermediate electrodes 123A of the surface-side intermediate electrode 28C and the back-side intermediate electrode 28D to one another.

[0186] A plurality of fourth vias 134A are provided. The number of fourth vias 134A is greater than the number of each of the first to third vias 131A to 133A and the fifth via 135A. The fourth vias 134A connect the fourth surface electrode 104A, the fourth back surface electrode 114A, and the fourth intermediate electrodes 124A of the surface-side intermediate electrode 28C and the back-side intermediate electrode 28D. This electrically connects the fourth surface electrode 104A, the fourth back surface electrode 114A, and the fourth intermediate electrodes 124A of the surface-side intermediate electrode 28C and the back-side intermediate electrode 28D.

[0187] The fifth via 135A connects the fifth surface electrode 105A, the first back surface electrode 111A, and the first intermediate electrode 121A of the surface-side intermediate electrode 28C and the back-side intermediate electrode 28D. This electrically connects the fifth surface electrode 105A, the first back surface electrode 111A, and the first intermediate electrode 121A of the surface-side intermediate electrode 28C and the back-side intermediate electrode 28D to one another. In other words, the first surface electrode 101A and the fifth surface electrode 105A are electrically connected via the first via 131A, the first intermediate electrode 121A of the surface-side intermediate electrode 28C, and the fifth via 135A.

[0188] 9, first to fourth semiconductor light emitting elements 30A to 30D, a first drive circuit 40A, a second drive circuit 40B, a third drive circuit 40C, and a fourth drive circuit 40D are mounted on a plurality of surface electrodes 28A. The semiconductor light emitting device 10 of the second embodiment also includes four protection diodes corresponding to the first to fourth semiconductor light emitting elements 30A to 30D. Hereinafter, the four protection diodes will be referred to as first to fourth protection diodes 50A to 50D. The first to fourth protection diodes 50A to 50D are mounted on a plurality of surface electrodes 28A.

[0189] The first to fourth semiconductor light emitting elements 30A to 30D are arranged at the same position in the Y direction and spaced apart from one another in the X direction. Therefore, it can be said that the first to fourth semiconductor light emitting elements 30A to 30D are aligned in the X direction. The first semiconductor light emitting element 30A and the first drive circuit 40A are aligned apart in the Y direction. The second semiconductor light emitting element 30B and the second drive circuit 40B are aligned apart in the Y direction. In one example, the first drive circuit 40A and the second drive circuit 40B are aligned in the X direction. The third semiconductor light emitting element 30C and the third drive circuit 40C are aligned apart in the X direction. The fourth semiconductor light emitting element 30D and the fourth drive circuit 40D are aligned apart in the X direction. In one example, the third drive circuit 40C and the fourth drive circuit 40D are aligned at the same position in the Y direction. As shown in FIG. 9, the third drive circuit 40C and the fourth drive circuit 40D are disposed separately on both sides of the third semiconductor light emitting element 30C and the fourth semiconductor light emitting element 30D in the X direction.

[0190] 9 , the first semiconductor light emitting element 30A and the third semiconductor light emitting element 30C, the first drive circuit 40A, the third drive circuit 40C, the first protection diode 50A, and the third protection diode 50C are arranged closer to the first substrate side surface 23 than the imaginary center line VC. The second semiconductor light emitting element 30B and the fourth semiconductor light emitting element 30D, the second drive circuit 40B, the fourth drive circuit 40D, the second protection diode 50B, and the fourth protection diode 50D are arranged closer to the second substrate side surface 24 than the imaginary center line VC. The first semiconductor light emitting element 30A and the third semiconductor light emitting element 30C, the first drive circuit 40A, the third drive circuit 40C, the first protection diode 50A, and the third protection diode 50C are symmetrical with the second semiconductor light emitting element 30B and the fourth semiconductor light emitting element 30D, the second drive circuit 40B, the fourth drive circuit 40D, the second protection diode 50B, and the fourth protection diode 50D about the imaginary center line VC. Therefore, hereinafter, the first semiconductor light emitting element 30A and the third semiconductor light emitting element 30C, the first drive circuit 40A, the third drive circuit 40C, the first protection diode 50A, and the third protection diode 50C will be described in detail with reference to FIG. 10 , and a detailed description of the second semiconductor light emitting element 30B and the fourth semiconductor light emitting element 30D, the second drive circuit 40B, the fourth drive circuit 40D, the second protection diode 50B, and the fourth protection diode 50D will be omitted.

[0191] The first semiconductor light emitting element 30A includes two semiconductor light emitting elements arranged side by side in the X direction. The two semiconductor light emitting elements are mounted on a first surface electrode 101A. Similar to the first semiconductor light emitting element 30A of the first embodiment, the first semiconductor light emitting element 30A has an element surface electrode 34 serving as an anode electrode formed on an element surface 31, and an element back surface electrode 35 serving as a cathode electrode formed on an element back surface 32 (both see FIG. 4 ). Therefore, the element back surface electrode 35 (cathode electrode) of the first semiconductor light emitting element 30A is electrically connected to the first surface electrode 101A.

[0192] The first switching element 411 of the first drive circuit 40A is mounted on the narrow portion of the second surface electrode 102A. Therefore, the first switching element 411 is disposed closer to the fourth substrate side surface 26 than the first semiconductor light emitting element 30A. The first switching element 411 is disposed in a position adjacent to the imaginary center line VC in the X direction. Therefore, the first switching element 411 is disposed in a position overlapping with the first semiconductor light emitting element 30A when viewed from the Y direction.

[0193] As in the first embodiment, the first switching element 411 has a source electrode 41S and a gate electrode 41G formed on the element surface 41A, and a drain electrode 41D (see FIG. 4 ) formed on the element back surface 41B. Therefore, the drain electrode 41D of the first switching element 411 is electrically connected to the second surface electrode 102A. Furthermore, the position of the gate electrode 41G of the first switching element 411 differs from that of the first switching element 411 of the first embodiment (see FIG. 1 ). The gate electrode 41G of the first switching element 411 is disposed at one of the four corners of the element surface 41A. The first switching element 411 is disposed such that the gate electrode 41G is adjacent to the third surface electrode 103A in the X direction in a plan view.

[0194] The element surface electrode 34 of the first semiconductor light emitting element 30A and the source electrode 41S of the first switching element 411 are connected by a wire W1. That is, the element surface electrodes 34 of the two semiconductor light emitting elements are each electrically connected to the source electrode 41S individually by the wire W1. In one example, in a plan view, the length of the wire W1 connecting the element surface electrode 34 and source electrode 41S of one semiconductor light emitting element is equal to the length of the wire W1 connecting the element surface electrode 34 and source electrode 41S of another semiconductor light emitting element.

[0195] The source electrode 41S and the fourth surface electrode 104A are connected by a wire W2, thereby electrically connecting the source electrode 41S and the fourth surface electrode 104A. The gate electrode 41G of the first switching element 411 and the third surface electrode 103A are connected by a wire W3, thereby electrically connecting the gate electrode 41G and the third surface electrode 103A.

[0196] The first capacitor 421 of the first drive circuit 40A is arranged closer to the fourth substrate side surface 26 in the Y direction than the first switching element 411. In other words, the first switching element 411 is arranged between the first semiconductor light emitting element 30A and the first capacitor 421 in the Y direction. In the example shown in Fig. 10 , the first switching element 411 is arranged closer to the first semiconductor light emitting element 30A in the Y direction than the center between the first capacitor 421 and the first semiconductor light emitting element 30A. In other words, the distance between the first semiconductor light emitting element 30A and the first switching element 411 in the Y direction is shorter than the distance between the first switching element 411 and the first capacitor 421 in the Y direction.

[0197] The first capacitor 421 is disposed so as to straddle the wide portion of the second surface electrode 102A and the fifth surface electrode 105A in the Y direction. The first electrode 42A of the first capacitor 421 is mounted on the second surface electrode 102A, and the second electrode 42B is mounted on the fifth surface electrode 105A. As a result, the first electrode 42A of the first capacitor 421 is electrically connected to the drain electrode 41D of the first switching element 411 via the second surface electrode 102A, and the second electrode 42B is electrically connected to the fifth surface electrode 105A. Because the fifth surface electrode 105A is electrically connected to the first surface electrode 101A, the second electrode 42B is electrically connected to the element back surface electrode 35 (cathode electrode) of the first semiconductor light emitting element 30A.

[0198] A plurality of first capacitors 421 (four in the second embodiment) are provided. The plurality of first capacitors 421 are arranged at the same positions in the Y direction and spaced apart from one another in the X direction. The X-direction dimensions of the wide portions of the second surface electrode 102A and the X-direction dimensions of the fifth surface electrode 105A are set according to the number of first capacitors 421.

[0199] According to this implementation mode of the first semiconductor light-emitting element 30A and the first drive circuit 40A, a loop-shaped first current path is formed in which current flows in the following order: the first electrode 42A of the first capacitor 421, the second surface electrode 102A, the drain electrode 41D of the first switching element 411, the source electrode 41S, the wire W1, the element surface electrode 34 (anode electrode) of the first semiconductor light-emitting element 30A, the element back surface electrode 35 (cathode electrode), the first surface electrode 101A, the first via 131A, the first intermediate electrode 121A, the fifth via 135A, the fifth surface electrode 105A, and the second electrode 42B of the first capacitor 421.

[0200] The third semiconductor light emitting element 30C includes two semiconductor light emitting elements arranged side by side in the X direction. The two semiconductor light emitting elements are mounted on a first surface electrode 101C. The third semiconductor light emitting element 30C is arranged at the same position in the Y direction as the first semiconductor light emitting element 30A. The third semiconductor light emitting element 30C is arranged closer to the first substrate side surface 23 than the first semiconductor light emitting element 30A.

[0201] Similar to the first semiconductor light emitting element 30C of the first embodiment, the third semiconductor light emitting element 30C has an element front surface electrode 34 formed on the element front surface 31 as an anode electrode, and an element back surface electrode 35 formed on the element back surface 32 as a cathode electrode. Therefore, the element back surface electrode 35 of the third semiconductor light emitting element 30C is electrically connected to the first surface electrode 101C. Here, the element front surface electrode 34 of the third semiconductor light emitting element 30C constitutes a third anode electrode. The element back surface electrode 35 of the third semiconductor light emitting element 30C constitutes a third cathode electrode.

[0202] In a plan view, the third switching element 413 of the third drive circuit 40C and the third semiconductor light emitting element 30C are arranged spaced apart from each other in the X direction. The third switching element 413 is mounted on a narrow portion of the second surface electrode 102C. Therefore, the third switching element 413 is arranged closer to the first substrate side surface 23 than the third semiconductor light emitting element 30C. The third switching element 413 is arranged in a position adjacent to the third semiconductor light emitting element 30C in the X direction. The third switching element 413 is arranged in a position adjacent to the third substrate side surface 25 in the Y direction. Therefore, the third switching element 413 is arranged in a position overlapping with the third semiconductor light emitting element 30C when viewed from the X direction.

[0203] As in the first embodiment, the third switching element 413 has a source electrode 41S and a gate electrode 41G formed on the element front surface 41A, and a drain electrode 41D (see FIG. 4) formed on the element back surface 41B. Therefore, the drain electrode 41D of the third switching element 413 is electrically connected to the second surface electrode 102C. Furthermore, in the third switching element 413, the position of the gate electrode 41G is different from that of the first switching element 411. In a plan view, the third switching element 413 is arranged so that the gate electrode 41G is adjacent to the third surface electrode 103C in the Y direction.

[0204] The element surface electrode 34 of the third semiconductor light emitting element 30C and the source electrode 41S of the third switching element 413 are connected by a wire W1. That is, each of the element surface electrodes 34 of the two semiconductor light emitting elements is individually electrically connected to the source electrode 41S by the wire W1. Furthermore, the source electrode 41S and the fourth surface electrode 104A are connected by a wire W2. This electrically connects the source electrode 41S and the fourth surface electrode 104A. In this way, the fourth surface electrode 104A is electrically connected to both the source electrode 41S of the first switching element 411 and the source electrode 41S of the third switching element 413. The gate electrode 41G of the third switching element 413 and the third surface electrode 103C are connected by a wire W3. This electrically connects the gate electrode 41G and the third surface electrode 103C.

[0205] The third capacitor 423 of the third drive circuit 40C is arranged closer to the first substrate side surface 23 in the X direction than the third switching element 413. In other words, the third switching element 413 is arranged between the third semiconductor light emitting element 30C and the third capacitor 423 in the X direction. In the example shown in Fig. 10 , the third switching element 413 is arranged closer to the third semiconductor light emitting element 30C in the X direction than the center between the third capacitor 423 and the third semiconductor light emitting element 30C. In other words, the distance between the third semiconductor light emitting element 30C and the third switching element 413 in the Y direction is shorter than the distance between the third switching element 413 and the third capacitor 423 in the Y direction.

[0206] The third capacitor 423 is disposed so as to straddle the wide portion of the second surface electrode 102C and the fifth surface electrode 105C in the X direction. The first electrode 42A of the third capacitor 423 is mounted on the second surface electrode 102C, and the second electrode 42B is mounted on the fifth surface electrode 105C. As a result, the first electrode 42A of the third capacitor 423 is electrically connected to the drain electrode 41D of the third switching element 413 via the second surface electrode 102C, and the second electrode 42B is electrically connected to the fifth surface electrode 105C. Because the fifth surface electrode 105C is electrically connected to the first surface electrode 101C, the second electrode 42B is electrically connected to the element back surface electrode 35 (cathode electrode) of the third semiconductor light emitting element 30C.

[0207] A plurality of third capacitors 423 (four in the second embodiment) are provided. The third capacitors 423 are arranged at the same positions in the X direction and spaced apart from one another in the Y direction. The Y direction dimensions of the wide portions of the second surface electrode 102C and the Y direction dimensions of the fifth surface electrode 105C are set according to the number of third capacitors 423.

[0208] According to this implementation mode of the third semiconductor light-emitting element 30C and the third drive circuit 40C, a loop-shaped third current path is formed in which current flows in the following order: the first electrode 42A of the third capacitor 423, the second surface electrode 102C, the drain electrode 41D of the third switching element 413, the source electrode 41S, the wire W1, the element surface electrode 34 (anode electrode) of the third semiconductor light-emitting element 30C, the element back surface electrode 35 (cathode electrode), the first surface electrode 101C, the first via 131C, the first intermediate electrode 121C, the fifth via 135C, the fifth surface electrode 105C, and the second electrode 42B of the third capacitor 423.

[0209] The first protection diode 50A is disposed closer to the fourth substrate side surface 26 in the Y direction than the first capacitor 421. The first protection diode 50A is disposed closer to the first substrate side surface 23 in the X direction than the first switching element 411. On the other hand, the first protection diode 50A is disposed in a position overlapping with a portion of the plurality of first capacitors 421 when viewed from the Y direction. Furthermore, the first protection diode 50A is disposed in a position overlapping with both the third semiconductor light emitting element 30C and the third switching element 413 when viewed from the Y direction.

[0210] The first protection diode 50A is disposed so as to straddle the fifth surface electrode 105A and the fourth surface electrode 104A in the X direction. The anode electrode 51 of the first protection diode 50A is mounted on the fifth surface electrode 105A, and the cathode electrode 52 is mounted on the fourth surface electrode 104A. Therefore, the anode electrode 51 of the first protection diode 50A is electrically connected to the second electrode 42B of the first capacitor 421 via the fifth surface electrode 105A. Furthermore, the second electrode 42B of the first capacitor 421 and the anode electrode 51 of the first protection diode 50A are electrically connected to the element back surface electrode 35 (cathode electrode) of the first semiconductor light emitting element 30A.

[0211] The third protection diode 50C is disposed closer to the first substrate side surface 23 in the Y direction than the third capacitor 423. The third protection diode 50C is disposed closer to the fourth substrate side surface 26 in the X direction than the third switching element 413. Meanwhile, the third protection diode 50C is disposed in a position overlapping with a portion of the plurality of third capacitors 423 when viewed from the X direction. Moreover, the third protection diode 50C is disposed in a position overlapping with both the first switching element 411 and the first capacitor 421 when viewed from the X direction.

[0212] The third protection diode 50C is disposed so as to straddle the fifth surface electrode 105C and the fourth surface electrode 104A in the Y direction. The anode electrode 51 of the third protection diode 50C is mounted on the fifth surface electrode 105C, and the cathode electrode 52 is mounted on the fourth surface electrode 104A. Therefore, the anode electrode 51 of the third protection diode 50C is electrically connected to the second electrode 42B of the third capacitor 423 via the fifth surface electrode 105C. Furthermore, the second electrode 42B of the third capacitor 423 and the anode electrode 51 of the third protection diode 50C are electrically connected to the element back surface electrode 35 (cathode electrode) of the third semiconductor light emitting element 30C.

[0213] The fourth front surface electrode 104A forms a ground wiring for connection to ground. The fourth back surface electrode 114A forms a ground terminal for connection to ground. Therefore, the source electrode 41S of the first switching element 411 and the source electrode 41S of the third switching element 413 and the cathode electrode 52 of the first protection diode 50A and the cathode electrode 52 of the third protection diode 50C are connected to ground.

[0214] Next, an overview of the fourth semiconductor light emitting element 30D and the fourth drive circuit 40D will be described. As shown in FIG. 9 , the fourth semiconductor light emitting element 30D has the same configuration as the first semiconductor light emitting element 30A, and therefore includes a front surface electrode 34 and a back surface electrode 35. The front surface electrode 34 of the fourth semiconductor light emitting element 30D constitutes a fourth anode electrode. The back surface electrode 35 of the fourth semiconductor light emitting element 30D constitutes a second cathode electrode.

[0215] Because the fourth switching element 414 of the fourth drive circuit 40D has the same configuration as the first switching element 411, the same reference numerals as those of the first switching element 411 are used for the components of the fourth switching element 414. Because the fourth capacitor 424 has the same configuration as the first capacitor 421, the same reference numerals as those of the first capacitor 421 are used for the components of the fourth capacitor 424.

[0216] In a plan view, the fourth semiconductor light emitting element 30D and the fourth switching element 414 are arranged spaced apart from each other in the X direction. In a plan view, the fourth switching element 414 is arranged between the fourth semiconductor light emitting element 30D and the fourth capacitor 424 in the X direction. The fourth switching element 414 is arranged closer to the fourth semiconductor light emitting element 30D than the fourth capacitor 424 in the X direction.

[0217] The drain electrode 41D of the fourth switching element 414 is electrically connected to the second surface electrode 102D, the source electrode 41S is electrically connected to the fourth surface electrode 104B, and the gate electrode 41G is electrically connected to the third surface electrode 103D. In addition, the source electrode 41S of the fourth switching element 414 is electrically connected to the element surface electrode 34 (fourth anode electrode) of the fourth semiconductor light emitting element 30D by a wire W1.

[0218] [Circuit Configuration of Semiconductor Light-Emitting Device] As shown in Figure 13, the light-emitting system 800 includes a DC power supply 801, a capacitor 802, and a current-limiting resistor 803, similar to the first embodiment. The light-emitting system 800 also includes gate driver ICs 805A-805D, pulse generators 806A-806D, and control power supplies 807A-807D corresponding to the first to fourth drive circuits 40A-40D. Unlike the first embodiment, the light-emitting system 800 also includes four backflow prevention diodes 804A-804D corresponding to the first to fourth semiconductor light-emitting elements 30A-30D. 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. Please refer to Figures 10 to 12 for detailed electrode configurations of the front electrode 28A and the back electrode 28B, and the first to fourth semiconductor light-emitting elements 30A to 30D, the first to fourth switching elements 411 to 414, the first to fourth capacitors 421 to 424, and the first to fourth protection diodes 50A to 50D.

[0219] 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 112A, the cathode of the reverse current blocking diode 804B is electrically connected to the second back surface electrode 112B, the cathode of the reverse current blocking diode 804C is electrically connected to the second back surface electrode 112C, and the cathode of the reverse current blocking diode 804D is electrically connected to the second back surface electrode 112D.

[0220] The cathode of the reverse current prevention diode 804A is electrically connected to the drain electrode 41D of the first switching element 411 in the first drive circuit 40A and the first electrode 42A of the first capacitor 421 via the second back surface electrode 112A. The cathode of the reverse current prevention diode 804B is electrically connected to the drain electrode 41D of the second switching element 412 in the second drive circuit 40B and the first electrode 42A of the second capacitor 422 via the second back surface electrode 112B. The cathode of the reverse current prevention diode 804C is electrically connected to the drain electrode 41D of the third switching element 413 in the third drive circuit 40C and the first electrode 42A of the third capacitor 423 via the second back surface electrode 112C. The cathode of the reverse current prevention diode 804D is electrically connected to the drain electrode 41D of the fourth switching element 414 in the fourth drive circuit 40D and the first electrode 42A of the fourth capacitor 424 via the second back surface electrode 112D.

[0221] The source electrode 41S of the first switching element 411 is electrically connected to the element surface electrode 34 (see FIG. 10 ) that serves as the anode electrode of the first semiconductor light emitting element 30A and the cathode electrode 52 of the first protection diode 50A. The source electrode 41S of the second switching element 412 is electrically connected to the element surface electrode 34 that serves as the anode electrode of the second semiconductor light emitting element 30B and the cathode electrode 52 of the second protection diode 50B. The source electrode 41S of the third switching element 413 is electrically connected to the element surface electrode 34 that serves as the anode electrode of the third semiconductor light emitting element 30C and the cathode electrode 52 of the third protection diode 50C. The source electrode 41S of the fourth switching element 414 is electrically connected to the element surface electrode 34 that serves as the anode electrode of the fourth semiconductor light emitting element 30D and the cathode electrode 52 of the fourth protection diode 50D.

[0222] The back surface electrode 35 serving as the cathode electrode of the first semiconductor light emitting element 30A is electrically connected to both the second electrode 42B of the first capacitor 421 and the anode electrode 51 of the first protection diode 50A. The back surface electrode 35 serving as the cathode electrode of the second semiconductor light emitting element 30B is electrically connected to both the second electrode 42B of the second capacitor 422 and the anode electrode 51 of the second protection diode 50B. The back surface electrode 35 serving as the cathode electrode of the third semiconductor light emitting element 30C is electrically connected to both the second electrode 42B of the third capacitor 423 and the anode electrode 51 of the third protection diode 50C. The back surface electrode 35 serving as the cathode electrode of the fourth semiconductor light emitting element 30D is electrically connected to both the second electrode 42B of the fourth capacitor 424 and the anode electrode 51 of the fourth protection diode 50D.

[0223] The source electrodes 41S of the first to fourth switching elements 411 to 414 and the cathode electrodes 52 of the first to fourth protection diodes 50A to 50D are connected to fourth back surface electrodes 114A and 114B, which serve as ground terminals, via ground wiring (fourth front surface electrodes 104A and 104B, front surface-side intermediate electrode 28C, and fourth intermediate electrodes 124A and 124B of back surface-side intermediate electrode 28D). The fourth back surface electrodes 114A and 114B are connected to ground.

[0224] The gate driver ICs 805A to 805D are individually electrically connected to the gate electrodes 41G of the first to fourth switching elements 411 to 414. In other words, the gate driver ICs 805A to 805D are configured to individually drive the first to fourth switching elements 411 to 414. Here, the gate driver IC 805A is an example of a "first gate drive circuit," the gate driver IC 805B is an example of a "second gate drive circuit," the gate driver IC 805C is an example of a "third gate drive circuit," and the gate driver IC 805D is an example of a "fourth gate drive circuit."

[0225] Pulse generators 806A to 806D and control power supplies 807A to 807D are individually and electrically connected to the gate driver ICs 805A to 805D. The connection structures of the gate driver ICs 805A to 805D, the pulse generators 806A to 806D, and the control power supplies 807A to 807D are the same as those in the first embodiment. Furthermore, the driving of the first to fourth semiconductor light emitting elements 30A to 30D in the semiconductor light emitting device 10 of the second embodiment is the same as that in the first embodiment.

[0226] [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.

[0227] (2-1) The third drive circuit 40C includes a third switching element 413 that controls the drive of the third semiconductor light emitting element 30C, and a third capacitor 423 that supplies current to the third semiconductor light emitting element 30C. The fourth drive circuit 40D includes a fourth switching element 414 that controls the drive of the fourth semiconductor light emitting element 30D, and a fourth capacitor 424 that supplies current to the fourth semiconductor light emitting element 30D.

[0228] According to this configuration, a loop-shaped third current path formed by the third semiconductor light-emitting element 30C, the third switching element 413, and the third capacitor 423 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 semiconductor light-emitting element 30D, the fourth switching element 414, and the fourth capacitor 424 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 current path and the fourth current path are short, variation in the lengths of the third current path and the fourth current path can be reduced. Therefore, variation in inductance of the third current path and the fourth current path can be reduced.

[0229] (2-2) In a plan view, the third semiconductor light emitting element 30C and the third capacitor 423 are arranged spaced apart from each other in the X direction. In a plan view, the third switching element 413 is arranged between the third semiconductor light emitting element 30C and the third capacitor 423 in the X direction. In a plan view, the fourth semiconductor light emitting element 30D and the fourth capacitor 424 are arranged spaced apart from each other in the X direction. In a plan view, the fourth switching element 414 is arranged between the fourth semiconductor light emitting element 30D and the fourth capacitor 424 in the Y direction.

[0230] With this configuration, compared to a configuration in which the third switching element 413 is arranged on the opposite side of the third semiconductor light emitting element 30C with respect to the third capacitor 423 in the X direction, it is possible to shorten the loop-shaped third current path formed by the third semiconductor light emitting element 30C, the third switching element 413, and the third capacitor 423. Furthermore, compared to a configuration in which the fourth switching element 414 is arranged on the opposite side of the fourth semiconductor light emitting element 30D with respect to the fourth capacitor 424 in the X direction, it is possible to shorten the loop-shaped fourth current path formed by the fourth semiconductor light emitting element 30D, the fourth switching element 414, and the fourth capacitor 424.

[0231] (2-3) The distance between the third semiconductor light emitting element 30C and the third switching element 413 in the X direction is equal to the distance between the fourth semiconductor light emitting element 30D and the fourth switching element 414 in the X direction.

[0232] According to this configuration, the current path between the third semiconductor light emitting element 30C and the third switching element 413 is equal to the current path between the fourth semiconductor light emitting element 30D and the fourth switching element 414. This reduces the variation in length between the third current path in a loop formed by the third semiconductor light emitting element 30C, the third switching element 413, and the third capacitor 423 and the fourth current path in a loop formed by the fourth semiconductor light emitting element 30D, the fourth switching element 414, and the fourth capacitor 424.

[0233] (2-4) There are provided a plurality of third capacitors 423 and a plurality of fourth capacitors 424. The plurality of third capacitors 423 are connected in parallel with one another. The plurality of fourth capacitors 424 are connected in parallel with one another.

[0234] According to this configuration, since the multiple third capacitors 423 are connected in parallel with each other, the total inductance of the multiple third capacitors 423 can be reduced to be lower than the inductance of each of the third capacitors 423. Furthermore, since the multiple fourth capacitors 424 are connected in parallel with each other, the total inductance of the multiple fourth capacitors 424 can be reduced to be lower than the inductance of each of the fourth capacitors 424.

[0235] (2-5) The multiple third capacitors 423 are arranged spaced apart from each other in the Y direction. The multiple fourth capacitors 424 are arranged spaced apart from each other in the Y direction. With this configuration, the arrangement direction (Y direction) of the multiple third capacitors 423 is orthogonal to the arrangement direction (X direction) of the third semiconductor light emitting element 30C, the third switching element 413, and the third capacitor 423 in a planar view. Therefore, the length of the loop-shaped third current path formed by the third semiconductor light emitting element 30C, the third switching element 413, and the third capacitor 423 can be shortened. The arrangement direction (Y direction) of the multiple fourth capacitors 424 is orthogonal to the arrangement direction (X direction) of the fourth semiconductor light emitting element 30D, the fourth switching element 414, and the fourth capacitor 424 in a planar view. Therefore, the length of the loop-shaped fourth current path formed by the fourth semiconductor light emitting element 30D, the fourth switching element 414, and the fourth capacitor 424 can be shortened.

[0236] (2-6) The semiconductor light emitting device 10 further includes a third protection diode 50C connected in anti-parallel to the third semiconductor light emitting element 30C, and a fourth protection diode 50D connected in anti-parallel to the fourth semiconductor light emitting element 30D.

[0237] According to this configuration, the third and fourth semiconductor light emitting elements 30C and 30D can be individually protected by the third and fourth protection diodes 50C and 50D.

[0238] (2-7) The third protection diode 50C is arranged on the opposite side of the third semiconductor light emitting element 30C with respect to the third switching element 413 in the X direction. The fourth protection diode 50D is arranged on the opposite side of the fourth semiconductor light emitting element 30D with respect to the fourth switching element 414 in the X direction. The third protection diode 50C is arranged to be spaced apart in the X direction from the third capacitor 423. The fourth protection diode 50D is arranged to be spaced apart in the X direction from the fourth capacitor 424.

[0239] According to this configuration, the length of the loop-shaped third current path formed by the third semiconductor light emitting element 30C, the third switching element 413, and the third capacitor 423 can be shortened compared to a configuration in which the third protection diode 50C is arranged between the third semiconductor light emitting element 30C and the third switching element 413 or between the third switching element 413 and the third capacitor 423. Furthermore, the length of the loop-shaped fourth current path formed by the fourth semiconductor light emitting element 30D, the fourth switching element 414, and the fourth capacitor 424 can be shortened compared to a configuration in which the fourth protection diode 50D is arranged between the fourth semiconductor light emitting element 30D and the fourth switching element 414 or between the fourth switching element 414 and the fourth capacitor 424.

[0240] (2-8) The region where the plurality of fifth vias 135C are formed is arranged at a position overlapping the region where the plurality of first vias 131C are formed when viewed from the X direction. The region where the plurality of fifth vias 135D are formed is arranged at a position overlapping the region where the plurality of first vias 131D are formed when viewed from the X direction.

[0241] With this configuration, among the loops of the third current path in which current flows in the order of the first electrode 42A of the third capacitor 423, the drain electrode 41D and source electrode 41S of the third switching element 413, the front surface electrode 34 and back surface electrode 35 of the third semiconductor light emitting element 30C, and the second electrode 42B of the third capacitor 423, the path through the first intermediate electrode 121C 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 42A of the fourth capacitor 424, the drain electrode 41D and source electrode 41S of the fourth switching element 414, the front surface electrode 34 and back surface electrode 35 of the fourth semiconductor light emitting element 30D, and the second electrode 42B of the fourth capacitor 424, the path through the first intermediate electrode 121D is a path along the X direction. Therefore, the loop of the fourth current path can be made smaller, thereby reducing the inductance of the fourth current path.

[0242] (2-9) The third switching element 413 is disposed at a position overlapping the third semiconductor light emitting element 30C when viewed from the X direction. The fourth switching element 414 is disposed at a position overlapping the fourth semiconductor light emitting element 30D when viewed from the X direction.

[0243] According to this configuration, the distance between the third switching element 413 and the third semiconductor light emitting element 30C can be shortened compared to a configuration in which the third switching element 413 is disposed at a position offset in the Y direction with respect to the third semiconductor light emitting element 30C. Therefore, when the source electrode 41S of the third switching element 413 and the element surface electrode 34 of the third semiconductor light emitting element 30C are connected by a wire W1, the length of the wire W1 can be shortened. Furthermore, the distance between the fourth switching element 414 and the fourth semiconductor light emitting element 30D can be shortened compared to a configuration in which the fourth switching element 414 is disposed at a position offset in the Y direction with respect to the fourth semiconductor light emitting element 30D. Therefore, when the source electrode 41S of the fourth switching element 414 and the element surface electrode 34 of the fourth semiconductor light emitting element 30D are connected by a wire W1, the length of the wire W1 can be shortened.

[0244] 14 to 19, 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 in the configuration of the first drive circuit 40A and the second drive circuit 40B. 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.

[0245] FIG. 14 shows a schematic planar structure of a semiconductor light-emitting device 10 according to the third embodiment. FIG. 15 shows an enlarged schematic planar structure of the semiconductor light-emitting device 10 of FIG. 14 , showing a portion between the imaginary center line VC and the first substrate side surface 23. FIG. 16 shows an enlarged schematic planar structure of the semiconductor light-emitting device 10 of FIG. 14 , showing a portion between the imaginary center line VC and the second substrate side surface 24. FIG. 17 shows a schematic back surface structure of the semiconductor light-emitting device 10 of FIG. 14 . FIG. 18 shows a schematic planar structure of the front-side intermediate electrode 28C in the semiconductor light-emitting device 10 of FIG. 14 . FIG. 19 shows a schematic circuit configuration of a light-emitting system 800 including the semiconductor light-emitting device 10 of FIG. 14 . Note that in FIGS. 14 to 16 , openings in the front resist 29A are indicated by two-dot chain lines. In FIG. 17 , openings in the back resist 29B are indicated by two-dot chain lines.

[0246] As shown in FIG. 14 , the semiconductor light emitting device 10 includes a first drive circuit 40A and a second drive circuit 40B, similar to the first embodiment. In the third embodiment, the semiconductor light emitting device 10 further includes gate driver ICs 805A and 805B and capacitors 808A and 808B. The gate driver IC 805A is configured to drive the first drive circuit 40A. The gate driver IC 805B is configured to drive the second drive circuit 40B. The capacitor 808A is electrically connected to the gate driver IC 805A. The capacitor 808B is electrically connected to the gate driver IC 805B.

[0247] The first drive circuit 40A includes a first switching element 411 and a plurality of (six in the third embodiment) first capacitors 421. The second drive circuit 40B includes a second switching element 412 and a plurality of (six in the third embodiment) second capacitors 422. Unlike the first embodiment, the first switching element 411 and the second switching element 412 of the third embodiment use horizontal transistors. In one example, the first switching element 411 and the second switching element 412 use transistors formed of a nitride semiconductor (e.g., gallium nitride (GaN)). An example of this transistor may be a high electron mobility transistor (HEMT) using a nitride semiconductor. Note that the first switching element 411 and the second switching element 412 may also use MOSFETs as long as they are horizontal transistors.

[0248] As described above, the configurations of the first switching element 411 and the second switching element 412 are different from those of the first embodiment, and the inclusion of gate driver ICs 805A, 805B and capacitors 808A, 808B results in a different configuration of the substrate 20. More specifically, the configurations of the front electrode 28A, the back electrode 28B, the front-side intermediate electrode 28C, and the back-side intermediate electrode 28D of the substrate 20 are different from those of the first embodiment. Below, the detailed configurations of the front electrode 28A, the back electrode 28B, the front-side intermediate electrode 28C, and the back-side intermediate electrode 28D will be described. Note that the configuration of the back-side intermediate electrode 28D is the same as that of the front-side intermediate electrode 28C, so the configuration of the front-side intermediate electrode 28C will be described and a description of the configuration of the back-side intermediate electrode 28D will be omitted.

[0249] 14 , the surface electrode 28A is formed on the substrate surface (substrate surface 21) of the surface-side substrate 27A. The surface electrode 28A includes first surface electrodes 151A and 151B, second surface electrodes 152A and 152B, a third surface electrode 153, fourth surface electrodes 154A and 154B, fifth surface electrodes 155A and 155B, sixth surface electrodes 156A and 156B, seventh surface electrodes 157A and 157B, and eighth surface electrodes 158A and 158B.

[0250] The first surface electrodes 151A, 151B are arranged at positions on the substrate surface 21 adjacent to the third substrate side surface 25 in the Y direction. The first surface electrode 151A is an electrode on which the first semiconductor light emitting element 30A is mounted, and the first surface electrode 151B is an electrode on which the second semiconductor light emitting element 30B is mounted. The first surface electrode 151A is an electrode electrically connected to the element back surface electrode 35 (not shown in FIG. 14 ) which serves as the cathode of the first semiconductor light emitting element 30A. The first surface electrode 151B is an electrode electrically connected to the element back surface electrode 35 (not shown in FIG. 14 ) which serves as the cathode of the second semiconductor light emitting element 30B.

[0251] The first surface electrodes 151A and 151B are arranged side by side in the X direction. The first surface electrode 151A is arranged adjacent to the virtual center line VC in the X direction and closer to the first substrate side surface 23 than the virtual center line VC. The first surface electrode 151B is arranged adjacent to the virtual center line VC in the X direction and closer to the second substrate side surface 24 than the virtual center line VC. The first surface electrodes 151A and 151B are strip-shaped with the X direction as the longitudinal direction and the Y direction as the lateral direction in a plan view. The first surface electrode 151A is formed over substantially the entire portion of the substrate surface 21 between the virtual center line VC and the first substrate side surface 23 in the X direction. The first surface electrode 151B is formed over substantially the entire portion of the substrate surface 21 between the virtual center line VC and the second substrate side surface 24 in the X direction.

[0252] The second surface electrode 152A, the third surface electrode 153, the fourth surface electrode 154A, and the fifth surface electrode 155A are electrodes electrically connected to the first drive circuit 40A. The second surface electrode 152B, the third surface electrode 153, the fourth surface electrode 154B, and the fifth surface electrode 155B are electrodes electrically connected to the second drive circuit 40B. In this way, the third surface electrode 153 is an electrode common to the first drive circuit 40A and the second drive circuit 40B.

[0253] The second surface electrode 152A and the third surface electrode 153 are electrodes electrically connected to the first capacitor 421. The second surface electrode 152B and the third surface electrode 153 are electrodes electrically connected to the second capacitor 422. The third surface electrode 153 is an electrode electrically connected to the source electrode 41S of each of the first switching element 411 and the second switching element 412. The fourth surface electrode 154A is an electrode electrically connected to the drain electrode 41D of the first switching element 411. The fourth surface electrode 154B is an electrode electrically connected to the drain electrode 41D of the second switching element 412. The fifth surface electrode 155A is an electrode electrically connected to the gate electrode 41G of the first switching element 411. The fifth surface electrode 155B is an electrode electrically connected to the gate electrode 41G of the second switching element 412.

[0254] The second surface electrodes 152A, 152B are arranged closer to the fourth substrate side surface 26 in the Y direction than the first surface electrodes 151A, 151B. The second surface electrodes 152A, 152B are arranged adjacent to the first surface electrodes 151A, 151B in the Y direction. In the example shown in Fig. 14, the Y direction dimensions of the second surface electrodes 152A, 152B are larger than the Y direction dimensions of the first surface electrodes 151A, 151B. Each of the first surface electrodes 151A, 151B and the second surface electrodes 152A, 152B is arranged closer to the third substrate side surface 25 than the center of the substrate surface 21 in the Y direction.

[0255] The third surface electrode 153 is disposed closer to the fourth substrate side surface 26 in the Y direction than the second surface electrodes 152A and 152B. The third surface electrode 153 is disposed adjacent to the second surface electrodes 152A and 152B in the Y direction. The third surface electrode 153 is formed over substantially the entire area between the second surface electrodes 152A and 152B and the fourth substrate side surface 26 in the Y direction. The third surface electrode 153 is formed so as to be spaced apart from both the first substrate side surface 23 and the second substrate side surface 24 in the X direction by the spaces in which the fifth to eighth surface electrodes 155A, 155B, 156A, 156B, 157A, 157B, 158A, and 158B are disposed.

[0256] The third surface electrode 153 includes six openings, which are oval openings with their longitudinal direction in the Y direction. The six openings are arranged at the same positions in the Y direction and spaced apart from one another in the X direction. Three openings closer to the first substrate side surface 23 than the imaginary center line VC are provided to correspond to the first switching element 411. Three openings closer to the second substrate side surface 24 than the imaginary center line VC are provided to correspond to the second switching element 412.

[0257] Three fourth surface electrodes 154A are individually arranged in the three openings closer to the first substrate side surface 23. Three fourth surface electrodes 154B are individually arranged in the three openings closer to the second substrate side surface 24. Of the six openings, the opening closest to the first substrate side surface 23 includes a first side opening that opens toward the first substrate side surface 23. A fifth surface electrode 155A is arranged in this first side opening. Of the six openings, the opening closest to the second substrate side surface 24 includes a second side opening that opens toward the second substrate side surface 24. A fifth surface electrode 155B is arranged in this second side opening. Each of the fourth surface electrodes 154A, 154B is formed in 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 fifth surface electrodes 155A, 155B 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.

[0258] The sixth to eighth surface electrodes 156A to 158A are electrodes on which the gate driver IC 805A is mounted, and the sixth to eighth surface electrodes 156B to 158B are electrodes on which the gate driver IC 805B is mounted. The seventh surface electrode 157A and the eighth surface electrode 158A are electrodes on which the capacitor 808A is mounted, and the seventh surface electrode 157B and the eighth surface electrode 158B are electrodes on which the capacitor 808B is mounted.

[0259] The sixth to eighth surface electrodes 156A to 158A are arranged in a region surrounded by the second surface electrode 152A, the third surface electrode 153, the fifth surface electrode 155A, the first substrate side surface 23, and the fourth substrate side surface 26. Therefore, the sixth to eighth surface electrodes 156A to 158A are arranged closer to the first substrate side surface 23 in the X direction than the third surface electrode 153 and the fifth surface electrode 155A. The sixth to eighth surface electrodes 156A to 158A are arranged closer to the fourth substrate side surface 26 in the Y direction than the second surface electrode 152A.

[0260] The sixth surface electrode 156A is disposed adjacent to the second surface electrode 152A in the Y direction. The sixth surface electrode 156A is disposed closer to the third substrate side surface 25 than the fifth surface electrode 155A in the Y direction. The seventh surface electrode 157A is disposed closer to the fourth substrate side surface 26 than the sixth surface electrode 156A in the Y direction. The seventh surface electrode 157A is disposed closer to the first substrate side surface 23 than the sixth surface electrode 156A in the X direction. When viewed from both the X direction and the Y direction, the seventh surface electrode 157A includes a portion that overlaps with the sixth surface electrode 156A. The sixth surface electrode 156A extends in the Y direction. The seventh surface electrode 157A is formed in a substantially L-shape in a plan view.

[0261] The eighth surface electrode 158A is disposed closer to the fourth substrate side surface 26 in the Y direction than the sixth surface electrode 156A and the seventh surface electrode 157A. The eighth surface electrode 158A is disposed adjacent to the seventh surface electrode 157A in the Y direction. In other words, the seventh surface electrode 157A includes a portion located between the sixth surface electrode 156A and the eighth surface electrode 158A in the Y direction. The eighth surface electrode 158A includes a portion adjacent to the fifth surface electrode 155A in the X direction. The eighth surface electrode 158A is rectangular in shape, with the Y direction as the longitudinal direction and the X direction as the lateral direction.

[0262] The sixth to eighth surface electrodes 156B to 158B are arranged in a region surrounded by the second surface electrode 152B, the third surface electrode 153, the fifth surface electrode 155B, the second substrate side surface 24, and the fourth substrate side surface 26. The sixth to eighth surface electrodes 156B to 158B are arranged closer to the second substrate side surface 24 in the X direction than the third surface electrode 153. The sixth to eighth surface electrodes 156B to 158B are arranged closer to the fourth substrate side surface 26 in the Y direction than the second surface electrode 152B.

[0263] The sixth surface electrode 156B is arranged closer to the fourth substrate side surface 26 in the Y direction than the fifth surface electrode 155B. The sixth surface electrode 156B extends in the Y direction. The seventh surface electrode 157B is arranged closer to the third substrate side surface 25 than the sixth surface electrode 156B in the Y direction. The seventh surface electrode 157B is arranged closer to the second substrate side surface 24 than the sixth surface electrode 156B in the X direction. When viewed from both the X direction and the Y direction, the seventh surface electrode 157B includes a portion that overlaps with the sixth surface electrode 156B. The seventh surface electrode 157B is formed in a substantially L-shape in a plan view.

[0264] The eighth surface electrode 158B is arranged closer to the third substrate side surface 25 in the Y direction than the sixth surface electrode 156B and the seventh surface electrode 157B. The eighth surface electrode 158B is arranged adjacent to the second surface electrode 152B in the Y direction. The eighth surface electrode 158B is arranged adjacent to the seventh surface electrode 157B in the Y direction. In other words, the seventh surface electrode 157B includes a portion located between the sixth surface electrode 156B and the eighth surface electrode 158B in the Y direction. The eighth surface electrode 158B includes a portion adjacent to the fifth surface electrode 155B in the X direction. The eighth surface electrode 158B is rectangular in shape, with the Y direction as the longitudinal direction and the X direction as the lateral direction.

[0265] 17 , the back surface electrode 28B is formed on the back surface (substrate back surface 22) of the back surface-side base material 27B. The back surface electrode 28B includes first back surface electrodes 161A, 161B, second back surface electrodes 162A, 162B, a third back surface electrode 163, fourth back surface electrodes 164A, 164B, and fifth back surface electrodes 165A, 165B.

[0266] The first back surface electrode 161A is an electrode electrically connected to both the first surface electrode 151A and each of the fourth surface electrodes 154A (see FIG. 14 ), and the first back surface electrode 161B is an electrode electrically connected to both the first surface electrode 151B and each of the fourth surface electrodes 154B (see FIG. 14 ). The first back surface electrode 161A is formed so as to overlap both the first surface electrode 151A and the fourth surface electrode 154A in a plan view. The first back surface electrode 161B is formed so as to overlap both the first surface electrode 151B and the fourth surface electrode 154B in a plan view. The first back surface electrodes 161A and 161B are formed in a substantially L-shape in a plan view. In one example, the first back surface electrodes 161A and 161B are in a line-symmetric relationship with respect to the imaginary center line VC. In one example, the total area of ​​the first back surface electrodes 161A and 161B is approximately half the area of ​​the substrate back surface 22 in a plan view.

[0267] The first back surface electrodes 161A, 161B include main electrode wiring 161AA, 161BA extending in the Y direction and extension wiring 161AB, 161BB extending from the main electrode wiring 161AA, 161BA in the X direction. In the third embodiment, the main electrode wiring 161AA and the extension wiring 161AB are integrated. The main electrode wiring 161BA and the extension wiring 161BB are integrated. The main electrode wiring 161AA, 161BA extend in the Y direction from a position adjacent to the third substrate side surface 25 to a position closer to the fourth substrate side surface 26 than the center of the substrate back surface 22. The main electrode wiring 161AA has a dimension in the X direction such that it overlaps with all three fourth surface electrodes 154A in a plan view. The main electrode wiring 161BA has a dimension in the X direction such that it overlaps with all three fourth surface electrodes 154B in a plan view. The extension wiring 161AB extends from an end of the main electrode wiring 161AA closer to the third substrate side surface 25 toward the first substrate side surface 23. The extension wiring 161BB extends from an end of the main electrode wiring 161BA closer to the third substrate side surface 25 toward the second substrate side surface 24.

[0268] The second back surface electrodes 162A and 162B are disposed adjacent to the extension wirings 161AB and 161BB in the Y direction. The second back surface electrode 162A is disposed in a position overlapping a portion of the second surface electrode 152A (see FIG. 14), and the second back surface electrode 162B is disposed in a position overlapping a portion of the second surface electrode 152B (see FIG. 14). In one example, the second back surface electrodes 162A and 162B are in a line-symmetric relationship with respect to the imaginary center line VC. The second back surface electrodes 162A and 162B are 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.

[0269] The third back surface electrode 163 is an electrode electrically connected to the third front surface electrode 153 and the seventh front surface electrodes 157A and 157B (see FIG. 14 ). The third back surface electrode 163 includes a U-shaped portion that surrounds the main electrode wirings 161AA and 161BA of the first back surface electrodes 161A and 161B from both sides in the X direction and from the fourth substrate side surface 26.

[0270] The third back surface electrode 163 includes a first branch wiring 163A extending from a portion adjacent to the main electrode wiring 161AA in the X direction toward the first substrate side surface 23, and a second branch wiring 163B extending from a portion adjacent to the main electrode wiring 161BA in the X direction toward the second substrate side surface 24. The first branch wiring 163A includes a portion overlapping with the seventh surface electrode 157A in a plan view. The second branch wiring 163B includes a portion overlapping with the seventh surface electrode 157B in a plan view.

[0271] The fourth back surface electrode 164A is an electrode electrically connected to the sixth surface electrode 156A (see FIG. 14), and the fourth back surface electrode 164B is an electrode electrically connected to the sixth surface electrode 156B (see FIG. 14).

[0272] The fourth back surface electrode 164A is disposed between the second back surface electrode 162A and the first branch wiring 163A in the Y direction. The fourth back surface electrode 164B is disposed between the second branch wiring 163B and the fourth substrate side surface 26 in the Y direction. Therefore, the fourth back surface electrode 164B is disposed closer to the fourth substrate side surface 26 in the Y direction than the fourth back surface electrode 164A. The fourth back surface electrode 164A includes a portion that overlaps with the sixth surface electrode 156A in a plan view. The fourth back surface electrode 164B includes a portion that overlaps with the sixth surface electrode 156B in a plan view.

[0273] The fifth back surface electrode 165A is an electrode electrically connected to the eighth surface electrode 158A (see FIG. 14), and the fifth back surface electrode 165B is an electrode electrically connected to the eighth surface electrode 158B (see FIG. 14).

[0274] The fifth back surface electrode 165A is disposed between the first branch wiring 163A and the fourth substrate side surface 26 in the Y direction. The fifth back surface electrode 165A is formed in a rectangular shape with the Y direction as its longitudinal direction and the X direction as its lateral direction. The fifth back surface electrode 165B is disposed between the second branch wiring 163B and the second back surface electrode 162B in the Y direction. Therefore, the fifth back surface electrode 165B is disposed closer to the third substrate side surface 25 than the fifth back surface electrode 165A.

[0275] (Front-side intermediate electrode) As shown in Fig. 18, the front-side intermediate electrode 28C is formed on the front surface of the intermediate substrate 27C. The back-side intermediate electrode 28D is formed on the back surface of the intermediate substrate 27C. The back-side intermediate electrode 28D has the same configuration as the front-side intermediate electrode 28C. Therefore, the following will describe the detailed configuration of the front-side intermediate electrode 28C, and will omit a description of the configuration of the back-side intermediate electrode 28D.

[0276] The front surface side intermediate electrode 28C includes first intermediate electrodes 171A and 171B, second intermediate electrodes 172A and 172B, a third intermediate electrode 173, fourth intermediate electrodes 174A and 174B, and fifth intermediate electrodes 175A and 175B.

[0277] The first intermediate electrode 171A is an electrode electrically connected to the first surface electrode 151A, the fourth surface electrode 154A (see FIG. 14 ), and the first back surface electrode 161A (see FIG. 17 ). The first intermediate electrode 171B is an electrode electrically connected to the first surface electrode 151B, the fourth surface electrode 154B (see FIG. 14 ), and the first back surface electrode 161B (see FIG. 17 ). The second intermediate electrode 172A is an electrode electrically connected to the second surface electrode 152A (see FIG. 14 ) and the second back surface electrode 162A (see FIG. 17 ). The second intermediate electrode 172B is an electrode electrically connected to the second surface electrode 152B (see FIG. 14 ) and the second back surface electrode 162B (see FIG. 17 ). The third intermediate electrode 173 is an electrode electrically connected to the third surface electrode 153, the seventh surface electrodes 157A and 157B (see FIG. 14 ), and the third back surface electrode 163. The fourth intermediate electrode 174A is an electrode electrically connected to the sixth surface electrode 156A (see FIG. 14 ) and the fourth back surface electrode 164A (see FIG. 17 ). The fourth intermediate electrode 174B is an electrode electrically connected to the sixth surface electrode 156B (see FIG. 14 ) and the fourth back surface electrode 164B (see FIG. 17 ). The fifth intermediate electrode 175A is an electrode electrically connected to the eighth surface electrode 158A (see FIG. 14 ) and the fifth back surface electrode 165A (see FIG. 17 ). The fifth intermediate electrode 175B is an electrode electrically connected to the eighth surface electrode 158B (see FIG. 14 ) and the fifth back surface electrode 165B (see FIG. 17 ).

[0278] The first intermediate electrodes 171A and 171B are disposed on both sides of the imaginary center line VC in the X direction. The first intermediate electrode 171A is disposed closer to the first substrate side surface 23 than the imaginary center line VC, and the first intermediate electrode 171B is disposed closer to the second substrate side surface 24 than the imaginary center line VC. The first intermediate electrode 171A is formed so as to overlap both the first surface electrode 151A and the fourth surface electrode 154A in a planar view. The first intermediate electrode 171B is formed so as to overlap both the first surface electrode 151B and the fourth surface electrode 154B in a planar view. The first intermediate electrodes 171A and 171B are rectangular in shape, with the Y direction as the longitudinal direction and the X direction as the lateral direction. The first intermediate electrodes 171A, 171B are located at the same positions as the main electrode wirings 161AA, 161BA (see FIG. 15) of the first rear surface electrodes 161A, 161B, and are arranged so as to overlap the main electrode wirings 161AA, 161BA in a plan view.

[0279] The third intermediate electrode 173 is formed to surround both first intermediate electrodes 171A and 171B from both sides in the X direction and from the fourth substrate side surface 26. The third intermediate electrode 173 includes a first wiring portion 173A arranged closer to the fourth substrate side surface 26 than the first intermediate electrodes 171A and 171B, a second wiring portion 173B arranged closer to the first substrate side surface 23 than the first intermediate electrode 171A, and a third wiring portion 173C arranged closer to the second substrate side surface 24 than the first intermediate electrode 171A. In the third embodiment, the first wiring portion 173A, the second wiring portion 173B, and the third wiring portion 173C are integrated. The first wiring portion 173A extends in the X direction. Both the second wiring portion 173B and the third wiring portion 173C extend in the Y direction.

[0280] The third intermediate electrode 173 includes two substantially rectangular first openings and four oval second openings. One second opening is formed in the first wiring portion 173A. One first opening and two second openings are formed in the second wiring portion 173B. One first opening and one second opening are formed in the second wiring portion 173B.

[0281] The second intermediate electrodes 172A and 172B are distributed over the two first openings. The second intermediate electrode 172A is disposed at a position overlapping both the second front surface electrode 152A and the second rear surface electrode 162A in a plan view. The second intermediate electrode 172B is disposed at a position overlapping both the second front surface electrode 152B and the second rear surface electrode 162B in a plan view. The second intermediate electrodes 172A and 172B are formed in a substantially rectangular shape with the X direction as the longitudinal direction and the Y direction as the lateral direction.

[0282] The fourth intermediate electrodes 174A, 174B and the fifth intermediate electrodes 175A, 175B are distributed among the four second openings. The fourth intermediate electrode 174A is positioned so as to overlap both the sixth surface electrode 156A and the fourth back surface electrode 164A in a planar view. The fourth intermediate electrode 174B is positioned so as to overlap both the sixth surface electrode 156B and the fourth back surface electrode 164B in a planar view. The fifth intermediate electrode 175A is positioned so as to overlap both the eighth surface electrode 158A and the fifth back surface electrode 165A in a planar view. The fifth intermediate electrode 175B is positioned so as to overlap both the eighth surface electrode 158B and the fifth back surface electrode 165B in a planar view. Each of the fourth intermediate electrodes 174A, 174B and the fifth intermediate electrodes 175A, 175B is formed in an oval shape with the Y direction as the longitudinal direction and the X direction as the lateral direction.

[0283] 15 to 18 , the substrate 20 includes first vias 181A to 181D, second vias 182A and 182B, third vias 183A to 183C, fourth vias 184A and 184B, and fifth vias 185A and 185B. The first vias 181A to 181D, second vias 182A and 182B, third vias 183A to 183C, fourth vias 184A and 184B, and fifth vias 185A and 185B 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 181A to 181D, the second vias 182A, 182B, the third vias 183A to 183C, the fourth vias 184A, 184B, and the fifth vias 185A, 185B are formed from a material containing one or more appropriately selected from the group consisting of Ti, TiN, Au, Ag, Cu, Al, and W.

[0284] A plurality of first vias 181A are provided. The first vias 181A connect the first surface electrode 151A, the first back surface electrode 161A, and the first intermediate electrodes 171A of the surface-side intermediate electrode 28C and the back-side intermediate electrode 28D. This electrically connects the first surface electrode 151A, the first back surface electrode 161A, and the first intermediate electrodes 171A of the surface-side intermediate electrode 28C and the back-side intermediate electrode 28D. In one example, the number of first vias 181A arranged in the X direction is greater than the number of first vias 181A arranged in the Y direction.

[0285] A plurality of first vias 181C are provided. The first vias 181C connect the fourth surface electrode 154A, the first back surface electrode 161A, and the first intermediate electrodes 171A of the front-side intermediate electrode 28C and the back-side intermediate electrode 28D. This electrically connects the fourth surface electrode 154A, the first back surface electrode 161A, and the first intermediate electrodes 171A of the front-side intermediate electrode 28C and the back-side intermediate electrode 28D. The first surface electrode 151A and the fourth surface electrode 154A are electrically connected to each other by the first vias 181A, 181C, the first back surface electrode 161A, and the first intermediate electrodes 171A of the front-side intermediate electrode 28C and the back-side intermediate electrode 28D.

[0286] A plurality of first vias 181B are provided. The first vias 181B connect the first surface electrode 151B, the first back surface electrode 161B, and the first intermediate electrodes 171B of the surface-side intermediate electrode 28C and the back-side intermediate electrode 28D. This electrically connects the first surface electrode 151B, the first back surface electrode 161B, and the first intermediate electrodes 171B of the surface-side intermediate electrode 28C and the back-side intermediate electrode 28D. In one example, the arrangement of the plurality of first vias 181B is the same as the arrangement of the plurality of first vias 181A.

[0287] A plurality of first vias 181D are provided. The first vias 181D connect the fourth surface electrode 154B, the first back surface electrode 161B, and the first intermediate electrodes 171B of the front-side intermediate electrode 28C and the back-side intermediate electrode 28D. This electrically connects the fourth surface electrode 154B, the first back surface electrode 161B, and the first intermediate electrodes 171B of the front-side intermediate electrode 28C and the back-side intermediate electrode 28D. The first surface electrode 151B and the fourth surface electrode 154B are electrically connected to each other by the first vias 181B, 181D, the first back surface electrode 161B, and the first intermediate electrodes 171B of the front-side intermediate electrode 28C and the back-side intermediate electrode 28D.

[0288] A plurality of second vias 182A are provided. The second vias 182A connect the second surface electrode 152A, the second back surface electrode 162A, and the second intermediate electrodes 172A of the surface-side intermediate electrode 28C and the back-side intermediate electrode 28D. This electrically connects the second surface electrode 152A, the second back surface electrode 162A, and the second intermediate electrodes 172A of the surface-side intermediate electrode 28C and the back-side intermediate electrode 28D to one another.

[0289] A plurality of second vias 182B are provided. The second vias 182B connect the second surface electrode 152B, the second back surface electrode 162B, and the second intermediate electrodes 172B of the surface-side intermediate electrode 28C and the back-side intermediate electrode 28D. This electrically connects the second surface electrode 152B, the second back surface electrode 162B, and the second intermediate electrodes 172B of the surface-side intermediate electrode 28C and the back-side intermediate electrode 28D to one another.

[0290] A plurality of third vias 183A are provided. The third vias 183A connect the third surface electrode 153, the third back surface electrode 163, and the first wiring portions 173A of the third intermediate electrodes 173 of the surface-side intermediate electrode 28C and the back-side intermediate electrode 28D. This electrically connects the third surface electrode 153, the third back surface electrode 163, and the third intermediate electrodes 173 of the surface-side intermediate electrode 28C and the back-side intermediate electrode 28D to one another. The number of third vias 183A is greater than the number of first vias 181A and 181B.

[0291] A plurality of third vias 183B are provided. The third vias 183B connect the seventh surface electrode 157A, the first branch wiring 163A of the third back surface electrode 163, and the second wiring portion 173B of the third intermediate electrode 173 of the front-side intermediate electrode 28C and the back-side intermediate electrode 28D. This electrically connects the seventh surface electrode 157A, the third back surface electrode 163, and the third intermediate electrode 173 of the front-side intermediate electrode 28C and the back-side intermediate electrode 28D. The third surface electrode 153 and the seventh surface electrode 157A are electrically connected by the third vias 183A and 183B, the third back surface electrode 163, and the third intermediate electrode 173 of the front-side intermediate electrode 28C and the back-side intermediate electrode 28D.

[0292] A plurality of third vias 183C are provided. The third vias 183C connect the seventh surface electrode 157B, the second branch wiring 163B of the third back surface electrode 163, and the third wiring portion 173C of the third intermediate electrode 173 of the front-side intermediate electrode 28C and the back-side intermediate electrode 28D. This electrically connects the seventh surface electrode 157B, the third back surface electrode 163, and the third intermediate electrode 173 of the front-side intermediate electrode 28C and the back-side intermediate electrode 28D. The third surface electrode 153 and the seventh surface electrode 157B are electrically connected by the third vias 183A and 183C, the third back surface electrode 163, and the third intermediate electrode 173 of the front-side intermediate electrode 28C and the back-side intermediate electrode 28D.

[0293] A plurality of fourth vias 184A are provided. The fourth vias 184A connect the sixth surface electrode 156A, the fourth back surface electrode 164A, and the fourth intermediate electrodes 174A of the surface-side intermediate electrode 28C and the back-side intermediate electrode 28D. This electrically connects the sixth surface electrode 156A, the fourth back surface electrode 164A, and the fourth intermediate electrodes 174A of the surface-side intermediate electrode 28C and the back-side intermediate electrode 28D.

[0294] A plurality of fourth vias 184B are provided. The fourth vias 184B connect the sixth surface electrode 156B, the fourth back surface electrode 164B, and the fourth intermediate electrodes 174B of the surface-side intermediate electrode 28C and the back-side intermediate electrode 28D. This electrically connects the sixth surface electrode 156B, the fourth back surface electrode 164B, and the fourth intermediate electrodes 174B of the surface-side intermediate electrode 28C and the back-side intermediate electrode 28D.

[0295] The fifth via 185A connects the eighth surface electrode 158A, the fifth back surface electrode 165A, and the fifth intermediate electrodes 175A of the surface-side intermediate electrode 28C and the back-side intermediate electrode 28D, thereby electrically connecting the eighth surface electrode 158A, the fifth back surface electrode 165A, and the fifth intermediate electrodes 175A of the surface-side intermediate electrode 28C and the back-side intermediate electrode 28D to one another.

[0296] The fifth via 185B connects the eighth surface electrode 158B, the fifth back surface electrode 165B, and the fifth intermediate electrodes 175B of the surface-side intermediate electrode 28C and the back-side intermediate electrode 28D, thereby electrically connecting the eighth surface electrode 158B, the fifth back surface electrode 165B, and the fifth intermediate electrodes 175B of the surface-side intermediate electrode 28C and the back-side intermediate electrode 28D to one another.

[0297] (Configuration and Arrangement of Semiconductor Light Emitting Element and Driving Circuit) The configuration and arrangement of the first semiconductor light emitting element 30A, the first driving circuit 40A, the first protection diode 50A, the gate driver IC 805A, and the capacitor 808A will be described with reference to FIG.

[0298] 15 , the first semiconductor light emitting element 30A is mounted on the first surface electrode 151A. As in the first embodiment, the first semiconductor light emitting element 30A is bonded to the first surface electrode 151A with a conductive bonding material SD. The first semiconductor light emitting element 30A is disposed at one of the two ends of the first surface electrode 151A in the X direction that is closer to the imaginary center line VC. The first semiconductor light emitting element 30A is disposed on the first surface electrode 151A closer to the third substrate side surface 25 in the Y direction.

[0299] The configuration of the first semiconductor light emitting element 30A is the same as that of the first embodiment. Therefore, the element back surface electrode 35 (not shown in FIG. 15 , see FIG. 4 ) that serves as the cathode of the first semiconductor light emitting element 30A is electrically connected to the first surface electrode 151A via the conductive bonding material SD.

[0300] Each of the four element surface electrodes 34 serving as the anodes of the first semiconductor light emitting element 30A is connected to the second surface electrode 152A by a wire W5. This electrically connects each element surface electrode 34 to the second surface electrode 152A. The four wires W5 individually connected to the four element surface electrodes 34 are formed to have approximately equal lengths in a plan view, for example. The number of wires W5 connected to each element surface electrode 34 can be changed as desired. In one example, four wires W5 may be connected to each element surface electrode 34. In this case, 16 wires W5 are connected to the first semiconductor light emitting element 30A.

[0301] The first switching element 411 and the multiple first capacitors 421 of the first drive circuit 40A are arranged closer to the fourth substrate side surface 26 than the first semiconductor light emitting element 30A. That is, in a plan view, the first semiconductor light emitting element 30A, the first switching element 411, and the multiple first capacitors 421 are arranged spaced apart from each other in the Y direction. The first switching element 411 is arranged on the opposite side of the multiple first capacitors 421 from the first semiconductor light emitting element 30A in the Y direction. In other words, the multiple first capacitors 421 are arranged between the first semiconductor light emitting element 30A and the first switching element 411 in the Y direction. In the third embodiment, the multiple first capacitors 421 are arranged closer to the first switching element 411 than the center between the first semiconductor light emitting element 30A and the first switching element 411 in the Y direction. That is, the distance between the multiple first capacitors 421 and the first switching element 411 in the Y direction is shorter than the distance between the multiple first capacitors 421 and the first semiconductor light emitting element 30A in the Y direction.

[0302] The multiple first capacitors 421 are arranged to straddle the second surface electrode 152A and the third surface electrode 153 in the Y direction. The multiple first capacitors 421 are arranged at the same positions in the Y direction and spaced apart from one another in the X direction. Each first capacitor 421 is mounted on the second surface electrode 152A and the third surface electrode 153. That is, each first capacitor 421 is individually bonded to the second surface electrode 152A and the third surface electrode 153 by a conductive bonding material SD. More specifically, the first electrode 42A of each first capacitor 421 is bonded to the second surface electrode 152A by the conductive bonding material SD, and the second electrode 42B of each first capacitor 421 is bonded to the third surface electrode 153 by the conductive bonding material SD. As a result, the first electrode 42A of each first capacitor 421 is electrically connected to the second surface electrode 152A, and the second electrode 42B of each first capacitor 421 is electrically connected to the third surface electrode 153. In this way, the multiple first capacitors 421 are connected in parallel with each other.

[0303] The first switching element 411 is disposed at a position overlapping with the third surface electrode 153, the plurality of fourth surface electrodes 154A, and the fifth surface electrode 155A in a plan view. The first switching element 411 is disposed at a position overlapping with the plurality of first capacitors 421 in a Y direction. The first switching element 411 includes a portion overlapping with the first semiconductor light emitting element 30A in a Y direction.

[0304] The first switching element 411 is formed in a rectangular plate shape with its thickness direction aligned in the Z direction. In the example shown in FIG. 15 , the first switching element 411 is rectangular in plan view with its longitudinal direction aligned in the X direction and its lateral direction aligned in the Y direction. A plurality of (three in the third embodiment) drain electrodes 41D, gate electrodes 41G, and a plurality of (three in the third embodiment) source electrodes 41S are formed on the back surface of the first switching element 411 facing the substrate surface 21. Each of the drain electrodes 41D, source electrodes 41S, and gate electrodes 41G is formed in a rectangular shape with its longitudinal direction aligned in the Y direction and its lateral direction aligned in the X direction.

[0305] The plurality of drain electrodes 41D are arranged at intervals from one another in the X direction. The plurality of source electrodes 41S are arranged at intervals from one another in the X direction. Of the plurality of source electrodes 41S, the source electrode 41S 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 41S.

[0306] The drain electrodes 41D and the source electrodes 41S are alternately arranged one by one in the X direction. In the example of FIG. 15 , the source electrode 41S, drain electrode 41D, source electrode 41S, drain electrode 41D, source electrode 41S, drain electrode 41D, source electrode 41S, drain electrode 41D, and source electrode 41S are arranged in this order from the end of the back surface of the first switching element 411 closest to the first substrate side surface 23 toward the end closest to the imaginary center line VC. Therefore, both ends of the back surface of the first switching element 411 in the X direction are source electrodes 41S. A gate electrode 41G is arranged at the end of the back surface of the first switching element 411 closest to the first substrate side surface 23. The gate electrode 41G and the source electrode 41S closest to the first substrate side surface 23 are arranged spaced apart from each other in the Y direction. The gate electrode 41G is arranged closer to the fourth substrate side surface 26 than the source electrode 41S closest to the first substrate side surface 23. The length of the gate electrode 41G in the Y direction is shorter than the length of the drain electrode 41D.

[0307] The plurality of drain electrodes 41D are arranged at positions where they individually overlap the plurality of fourth surface electrodes 154A in a plan view. The plurality of drain electrodes 41D are individually bonded to the plurality of fourth surface electrodes 154A by a conductive bonding material SD. As a result, the plurality of drain electrodes 41D are individually electrically connected to the plurality of fourth surface electrodes 154A. The plurality of source electrodes 41S are arranged at positions where they overlap the third surface electrode 153. The plurality of source electrodes 41S are bonded to the third surface electrode 153 by a conductive bonding material SD. As a result, the plurality of source electrodes 41S are electrically connected to the third surface electrode 153. The gate electrode 41G is arranged at a position where it overlaps the fifth surface electrode 155A. The gate electrode 41G is bonded to the fifth surface electrode 155A by a conductive bonding material SD. As a result, the gate electrode 41G is electrically connected to the fifth surface electrode 155A. In this way, it can be said that the source electrode 41S, the drain electrode 41D, and the gate electrode 41G of the first switching element 411 are mounted on the plurality of surface electrodes 28A.

[0308] According to this implementation mode of the first semiconductor light-emitting element 30A and the first drive circuit 40A, a loop-shaped first current path is formed in which current flows in the following order: the first electrode 42A of the first capacitor 421, the second surface electrode 152A, the wire W5, the element surface electrode 34 (anode electrode) of the first semiconductor light-emitting element 30A, the element back surface electrode 35 (cathode electrode), the first surface electrode 151A, the first via 181A, the first intermediate electrode 171A, the first via 181C, the fourth surface electrode 154A, the drain electrode 41D of the first switching element 411, the source electrode 41S, the third surface electrode 153, and the second electrode 42B of the first capacitor 421.

[0309] The first protection diode 50A is arranged closer to the first substrate side surface 23 in the X direction than the first semiconductor light emitting element 30A. The first protection diode 50A is arranged closer to the first substrate side surface 23 in the X direction than the first switching element 411 and the plurality of first capacitors 421. The first protection diode 50A is arranged closer to the third substrate side surface 25 in the Y direction than the first switching element 411 and the plurality of first capacitors 421.

[0310] The first protection diode 50A is disposed so as to straddle the first surface electrode 151A and the second surface electrode 152A in the Y direction. The first protection diode 50A is mounted on the first surface electrode 151A and the second surface electrode 152A. More specifically, the first protection diode 50A is individually bonded to the first surface electrode 151A and the second surface electrode 152A by a conductive bonding material SD. More specifically, the anode electrode 51 of the first protection diode 50A is bonded to the first surface electrode 151A by the conductive bonding material SD, and the cathode electrode 52 of the first protection diode 50A is bonded to the second surface electrode 152A by the conductive bonding material SD. As a result, the anode electrode 51 of the first protection diode 50A is electrically connected to the first surface electrode 151A, and the cathode electrode 52 of the first protection diode 50A is electrically connected to the second surface electrode 152A. That is, the anode electrode 51 of the first protection diode 50A is electrically connected to the back surface electrode 35 of the first semiconductor light emitting element 30A, which serves as the cathode of the first semiconductor light emitting element 30A, and the cathode electrode 52 of the first protection diode 50A is electrically connected to the front surface electrode 34 of the first semiconductor light emitting element 30A, which serves as the anode of the first semiconductor light emitting element 30A. In this way, the first protection diode 50A is connected in anti-parallel to the first semiconductor light emitting element 30A.

[0311] 14, the gate driver IC 805A and the capacitor 808A are arranged on the opposite side of the first switching element 411 from the second switching element 412 in the X direction. In other words, the gate driver IC 805A is arranged closer to the first substrate side surface 23 in the X direction than the first switching element 411. The gate driver IC 805A is arranged in the same position as the first switching element 411 in the Y direction.

[0312] The gate driver IC 805A is disposed at a position overlapping the third surface electrode 153, the fifth surface electrode 155A, the sixth surface electrode 156A, the seventh surface electrode 157A, and the eighth surface electrode 158A in a plan view. The gate driver IC 805A is formed in a rectangular plate shape with its thickness direction in the Z direction. In one example, the dimensions of the gate driver IC 805A in the X direction and the Y direction are smaller than those of the first switching element 411. The gate driver IC 805A includes a plurality of terminals 805P (five in the third embodiment) on a driver rear surface facing the substrate surface 21.

[0313] Terminals 805P of the gate driver IC 805A are mounted on the third surface electrode 153, the fifth surface electrode 155A, the sixth surface electrode 156A, the seventh surface electrode 157A, and the eighth surface electrode 158A, so that the gate driver IC 805A is electrically connected to the third surface electrode 153, the fifth surface electrode 155A, the sixth surface electrode 156A, the seventh surface electrode 157A, and the eighth surface electrode 158A, respectively.

[0314] The gate driver IC 805A is electrically connected to the gate electrode 41G of the first switching element 411 via the fifth surface electrode 155A. A control power supply 807A (see FIG. 19 ), which will be described later, is electrically connected to the eighth surface electrode 158A. As a result, power is supplied to the gate driver IC 805A from the control power supply 807A via the eighth surface electrode 158A. A pulse generator 806A (see FIG. 19 ), which will be described later, is electrically connected to the sixth surface electrode 156A. As a result, a pulse signal from the pulse generator 806A is input to the gate driver IC 805A via the sixth surface electrode 156A.

[0315] The capacitor 808A is arranged closer to the first substrate side surface 23 in the X direction than the gate driver IC 805A. In other words, the gate driver IC 805A is arranged between the first switching element 411 and the capacitor 808A in the X direction. The capacitor 808A is arranged in a position overlapping both the gate driver IC 805A and the first switching element 411 when viewed from the X direction.

[0316] The capacitor 808A is mounted on the seventh surface electrode 157A and the eighth surface electrode 158A. The capacitor 808A is disposed so as to straddle the seventh surface electrode 157A and the eighth surface electrode 158A in the Y direction. The capacitor 808A includes a first electrode 808P and a second electrode 808Q. The first electrode 808P is electrically connected to the seventh surface electrode 157A, and the second electrode 808Q is electrically connected to the eighth surface electrode 158A. The capacitor 808A is electrically connected to the gate driver IC 805A via the seventh surface electrode 157A and the eighth surface electrode 158A.

[0317] The configurations and arrangements of the second semiconductor light emitting element 30B, the second drive circuit 40B, the second protection diode 50B, the gate driver IC 805B, and the capacitor 808B will be described with reference to FIG.

[0318] 16 , the second semiconductor light emitting element 30B is mounted on the first surface electrode 151B. As in the first embodiment, the second semiconductor light emitting element 30B is bonded to the first surface electrode 151B with a conductive bonding material SD. The second semiconductor light emitting element 30B is disposed at one of both ends of the first surface electrode 151B in the X direction that is closer to the imaginary center line VC. The second semiconductor light emitting element 30B is disposed on the first surface electrode 151B closer to the third substrate side surface 25 in the Y direction. The second semiconductor light emitting element 30B is disposed adjacent to the first semiconductor light emitting element 30A in the X direction.

[0319] The configuration of the second semiconductor light emitting element 30B is the same as that of the first embodiment. Therefore, the element back surface electrode 35 (not shown), which serves as the cathode of the second semiconductor light emitting element 30B, is electrically connected to the first surface electrode 151B via the conductive bonding material SD.

[0320] Each of the four element surface electrodes 34 serving as the anodes of the second semiconductor light emitting element 30B is connected to the second surface electrode 152B by a wire W6. This electrically connects each element surface electrode 34 to the second surface electrode 152B. The four wires W6 individually connected to the four element surface electrodes 34 are formed, for example, to have approximately equal lengths in a planar view. The total length of the four wires W6 is equal to the total length of the four wires W5. Here, if the difference between the total length of the four wires W6 and the total length of the four wires W5 is, for example, within 10% of the total length of the four wires W6, then the total length of the four wires W6 can be said to be equal to the total length of the four wires W5. The number of wires W6 connected to each element surface electrode 34 can be arbitrarily changed. For example, four wires W6 may be connected to each element surface electrode 34. In this case, 16 wires W6 are connected to the second semiconductor light emitting element 30B.

[0321] In the second drive circuit 40B, the second switching element 412 and the multiple second capacitors 422 are arranged closer to the fourth substrate side surface 26 than the second semiconductor light emitting element 30B. That is, in a plan view, the second semiconductor light emitting element 30B, the second switching element 412, and the multiple second capacitors 422 are arranged spaced apart from each other in the Y direction. The second switching element 412 is arranged on the opposite side of the multiple second capacitors 422 from the second semiconductor light emitting element 30B in the Y direction. In other words, the multiple second capacitors 422 are arranged between the second semiconductor light emitting element 30B and the second switching element 412 in the Y direction. Each second capacitor 422 is arranged closer to the second switching element 412 than the second semiconductor light emitting element 30B in the Y direction. That is, the distance between the second capacitor 422 and the second switching element 412 in the Y direction is smaller than the distance between the second capacitor 422 and the second semiconductor light emitting element 30B in the Y direction.

[0322] The multiple second capacitors 422 are arranged so as to straddle the second surface electrode 152B and the third surface electrode 153 in the Y direction. The multiple second capacitors 422 are arranged at the same positions as one another in the Y direction and spaced apart from one another in the X direction. Each second capacitor 422 is mounted on the second surface electrode 152B and the third surface electrode 153. That is, each second capacitor 422 is individually bonded to the second surface electrode 152B and the third surface electrode 153 by a conductive bonding material SD. More specifically, the first electrode 42A of each second capacitor 422 is bonded to the second surface electrode 152B by the conductive bonding material SD, and the second electrode 42B of each second capacitor 422 is bonded to the third surface electrode 153 by the conductive bonding material SD. As a result, the first electrode 42A of each second capacitor 422 is electrically connected to the second surface electrode 152B, and the second electrode 42B of each second capacitor 422 is electrically connected to the third surface electrode 153. In this manner, the multiple second capacitors 422 are connected in parallel with each other. Furthermore, the second electrodes 42B (see FIG. 15 ) of the multiple first capacitors 421 and the second electrodes 42B of the multiple second capacitors 422 are electrically connected via the third surface electrode 153.

[0323] The second switching element 412 is disposed at a position overlapping with the third surface electrode 153, the plurality of fourth surface electrodes 154B, and the fifth surface electrode 155B in a plan view. The second switching element 412 is disposed at a position overlapping with the plurality of second capacitors 422 in a Y direction. The second switching element 412 includes a portion overlapping with the second semiconductor light emitting element 30B in a Y direction.

[0324] The second switching element 412 is a switching element having the same configuration and size as the first switching element 411 (see FIG. 15 ). In the example shown in FIG. 16 , the second switching element 412 is arranged such that the X direction is the longitudinal direction and the Y direction is the lateral direction in a plan view. In the example shown in FIG. 16 , a source electrode 41S, a drain electrode 41D, a source electrode 41S, a drain electrode 41D, a source electrode 41S, a drain electrode 41D, and a source electrode 41S are arranged in this order from the end of the back surface of the second switching element 412 closest to the second substrate side surface 24 toward the end closest to the imaginary center line VC. Therefore, both ends of the back surface of the second switching element 412 in the X direction are the source electrode 41S. A gate electrode 41G is arranged at the end of the back surface of the second switching element 412 closest to the second substrate side surface 24. The gate electrode 41G and the source electrode 41S closest to the second substrate side surface 24 are arranged spaced apart from each other in the Y direction. The gate electrode 41G is disposed closer to the third substrate side surface 25 than the source electrode 41S, which is closest to the second substrate side surface 24. The drain electrodes 41D are disposed at positions overlapping the fourth surface electrodes 154B individually in a plan view. The drain electrodes 41D are individually bonded to the fourth surface electrodes 154B with a conductive bonding material SD. As a result, the drain electrodes 41D are individually electrically connected to the fourth surface electrodes 154B. The source electrodes 41S are disposed at positions overlapping the third surface electrodes 153. The source electrodes 41S are bonded to the third surface electrode 153 with a conductive bonding material SD. As a result, the source electrodes 41S are electrically connected to the third surface electrode 153. The source electrodes 41S of the second switching element 412 and the source electrodes 41S of the first switching element 411 (see FIG. 15 ) are electrically connected via the third surface electrode 153. The gate electrode 41G is disposed at a position overlapping the fifth surface electrode 155B. The gate electrode 41G is joined to the fifth surface electrode 155B by a conductive bonding material SD. As a result, the gate electrode 41G is electrically connected to the fifth surface electrode 155B.In this way, it can be said that the source electrode 41S, the drain electrode 41D, and the gate electrode 41G of the second switching element 412 are mounted on the plurality of surface electrodes 28A.

[0325] According to this implementation mode of the second semiconductor light-emitting element 30B and the second drive circuit 40B, a loop-shaped second current path is formed in which current flows in the following order: the first electrode 42A of the second capacitor 422, the second surface electrode 152B, the wire W6, the element surface electrode 34 (anode electrode) of the second semiconductor light-emitting element 30B, the element back surface electrode 35 (cathode electrode), the first surface electrode 151B, the first via 181B, the first intermediate electrode 171B, the first via 181D, the fourth surface electrode 154B, the drain electrode 41D of the second switching element 412, the source electrode 41S, the third surface electrode 153, and the second electrode 42B of the second capacitor 422.

[0326] The second protection diode 50B is arranged closer to the second substrate side surface 24 in the X direction than the second semiconductor light emitting element 30B. The second protection diode 50B is arranged closer to the second substrate side surface 24 in the X direction than the second switching element 412 and the plurality of second capacitors 422. The second protection diode 50B is arranged closer to the third substrate side surface 25 in the Y direction than the second switching element 412 and the plurality of second capacitors 422.

[0327] The second protection diode 50B is disposed so as to straddle the first surface electrode 151B and the second surface electrode 152B in the Y direction. Like the first protection diode 50A, the second protection diode 50B is mounted on the first surface electrode 151B and the second surface electrode 152B. Therefore, the anode electrode 51 of the second protection diode 50B is electrically connected to the first surface electrode 151B, and the cathode electrode 52 of the second protection diode 50B is electrically connected to the second surface electrode 152B. In other words, the anode electrode 51 of the second protection diode 50B is electrically connected to the element back surface electrode 35, which serves as the cathode of the second semiconductor light emitting element 30B, and the cathode electrode 52 of the second protection diode 50B is electrically connected to the element front surface electrode 34, which serves as the anode of the second semiconductor light emitting element 30B. In this manner, the second protection diode 50B is connected in anti-parallel to the second semiconductor light emitting element 30B.

[0328] 14 , the gate driver IC 805B and the capacitor 808B are arranged on the opposite side of the second switching element 412 from the first switching element 411 in the X direction. In other words, the gate driver IC 805B is arranged closer to the second substrate side surface 24 than the second switching element 412 in the X direction. The gate driver IC 805B is arranged in the same position as the second switching element 412 in the Y direction. In this way, the first switching element 411 and the second switching element 412 are arranged adjacent to each other in the X direction. In other words, no other elements such as a gate driver or a capacitor are arranged between the first switching element 411 and the second switching element 412 in the X direction.

[0329] The gate driver IC 805B is disposed at a position overlapping the third surface electrode 153, the fifth surface electrode 155B, the sixth surface electrode 156B, the seventh surface electrode 157B, and the eighth surface electrode 158B in a plan view. The gate driver IC 805B is formed in a rectangular plate shape with its thickness direction in the Z direction. In one example, the dimensions of the gate driver IC 805B in the X direction and the Y direction are smaller than those of the second switching element 412. The gate driver IC 805B includes a plurality of terminals 805P (five in the third embodiment) on its driver back surface facing the substrate surface 21.

[0330] Terminals 805P of the gate driver IC 805B are mounted on the third surface electrode 153, the fifth surface electrode 155B, the sixth surface electrode 156B, the seventh surface electrode 157B, and the eighth surface electrode 158B, thereby being individually and electrically connected to the gate driver IC 805B, the third surface electrode 153, the fifth surface electrode 155B, the sixth surface electrode 156B, the seventh surface electrode 157B, and the eighth surface electrode 158B.

[0331] The gate driver IC 805B is electrically connected to the gate electrode 41G of the second switching element 412 via the fifth surface electrode 155B. A control power supply 807B (see FIG. 19 ), which will be described later, is electrically connected to the eighth surface electrode 158B. As a result, power is supplied to the gate driver IC 805B from the control power supply 807B via the eighth surface electrode 158B. A pulse generator 806B (see FIG. 19 ), which will be described later, is electrically connected to the sixth surface electrode 156B. As a result, a pulse signal from the pulse generator 806B is input to the gate driver IC 805B via the sixth surface electrode 156B.

[0332] The capacitor 808B is arranged closer to the second substrate side surface 24 in the X direction than the gate driver IC 805B. In other words, the gate driver IC 805B is arranged between the second switching element 412 and the capacitor 808B in the X direction. The capacitor 808B is arranged in a position overlapping both the gate driver IC 805B and the second switching element 412 when viewed from the X direction. The configuration and size of the capacitor 808B are the same as those of the capacitor 808A.

[0333] The capacitor 808B is mounted on the seventh surface electrode 157B and the eighth surface electrode 158B. The capacitor 808B is arranged to straddle the seventh surface electrode 157B and the eighth surface electrode 158B in the Y direction. A first electrode 808P of the capacitor 808B is electrically connected to the seventh surface electrode 157B, and a second electrode 808Q is electrically connected to the eighth surface electrode 158B. The capacitor 808B is electrically connected to the gate driver IC 805B via the seventh surface electrode 157B and the eighth surface electrode 158B.

[0334] [Circuit Configuration of Semiconductor Light-Emitting Device] A light-emitting system 800 including the semiconductor light-emitting device 10 of the third embodiment will be described with reference to Figure 19. Below, configurations that differ from the light-emitting system 800 of the first embodiment will be described in detail, and configurations that are common to the light-emitting system 800 of the first embodiment will be denoted by the same reference numerals and will not be described again. For the electrodes of the front electrode 28A, the back electrode 28B, the first semiconductor light-emitting element 30A, the second semiconductor light-emitting element 30B, the first switching element 411, the second switching element 412, the first capacitor 421, and the second capacitor 422, please refer to Figures 15 and 16.

[0335] 19 , in the semiconductor light-emitting device 10, the cathode of the reverse current prevention diode 804A is electrically connected to each of the first electrode 42A of the first capacitor 421 in the first drive circuit 40A, the anode (element surface electrode 34) of the first semiconductor light-emitting element 30A, and the cathode electrode of the first protection diode 50A. The cathode of the reverse current prevention diode 804B is electrically connected to each of the first electrode 42A of the second capacitor 422 in the second drive circuit 40B, the anode (element surface electrode 34) of the second semiconductor light-emitting element 30B, and the cathode electrode of the second protection diode 50B.

[0336] The first protection diode 50A is connected in anti-parallel to the first semiconductor light emitting element 30A. The second protection diode 50B is connected in anti-parallel to the second semiconductor light emitting element 30B. The drain electrode 41D of the first switching element 411 of the first drive circuit 40A is electrically connected to both the cathode (back surface electrode 35) of the first semiconductor light emitting element 30A and the anode electrode of the first protection diode 50A. The source electrode 41S is connected to ground via a third back surface electrode 163. The drain electrode 41D of the second switching element 412 of the second drive circuit 40B is electrically connected to both the cathode (back surface electrode 35) of the second semiconductor light emitting element 30B and the anode electrode of the second protection diode 50B. The source electrode 41S is connected to ground via a third surface electrode 153 and a third back surface electrode 163. The third surface electrode 153 forms a ground wiring, and the third back surface electrode 163 forms a ground terminal.

[0337] The gate driver IC 805A is electrically connected to the gate electrode 41G of the first switching element 411. The gate driver IC 805B is individually and electrically connected to the gate electrode 41G of the second switching element 412. The gate driver ICs 805A and 805B are electrically connected to the third back surface electrode 163. The gate driver ICs 805A and 805B are provided inside the semiconductor light emitting device 10. On the other hand, the pulse generators 806A and 806B and the control power supplies 807A and 807B are provided outside the semiconductor light emitting device 10.

[0338] The negative electrodes of the pulse generator 806A and the control power supply 807A are each electrically connected to the third back surface electrode 163. The negative electrodes of the pulse generator 806B and the control power supply 807B are each electrically connected to the third back surface electrode 163. The negative electrode of the DC power supply 801 and the capacitor 802 are electrically connected to the third back surface electrode 163. In addition, the negative electrode of the DC power supply 801, the capacitor 802, the pulse generators 806A and 806B, and the negative electrodes of the control power supplies 807A and 807B are each connected to ground. Therefore, the third back surface electrode 163 is connected to ground.

[0339] The driving operation of each of the semiconductor light-emitting elements 30A and 30B in the semiconductor light-emitting device 10 will now be described. When the first switching element 411 is in the OFF state, the first capacitor 421 is charged by the DC power supply 801. When the first switching element 411 is changed from the OFF state to the ON state, a current flows from the first capacitor 421 to the first semiconductor light-emitting element 30A. This causes pulsed laser light to be emitted from the light-emitting portion 33 of the first semiconductor light-emitting element 30A. The current that has flowed through the first semiconductor light-emitting element 30A flows to ground via the first switching element 411.

[0340] Furthermore, when the second switching element 412 is in the OFF state, the second capacitor 422 is charged by the DC power supply 801. When the second switching element 412 is changed from the OFF state to the ON state, a current flows from the second capacitor 422 to the light-emitting unit 33 of the second semiconductor light-emitting element 30B. This causes the light-emitting unit 33 to emit pulsed laser light. The current that has flowed through the second semiconductor light-emitting element 30B flows to ground via the second switching element 412.

[0341] In this way, the driving of the first semiconductor light emitting element 30A is controlled by the first drive circuit 40A, and the driving of the second semiconductor light emitting element 30B is controlled by the second drive circuit 40B. In other words, the first semiconductor light emitting element 30A and the second semiconductor light emitting element 30B are individually controlled by the first drive circuit 40A and the second drive circuit 40B.

[0342] As an example, the first semiconductor light-emitting element 30A and the second semiconductor light-emitting element 30B are sequentially driven by the first drive circuit 40A and the second drive circuit 40B. In this case, the pulsed light emissions of the first semiconductor light-emitting element 30A and the second semiconductor light-emitting element 30B can be adjusted so that the pulse intervals of the laser light emitted by the semiconductor light-emitting device 10 are shorter than in a semiconductor light-emitting device including, for example, a single semiconductor light-emitting element. This allows for an increase in the number of pulses per unit time. In addition, by alternately emitting light from the first semiconductor light-emitting element 30A and the second semiconductor light-emitting element 30B, heat generation from each of the semiconductor light-emitting elements 30A and 30B can be suppressed compared to a semiconductor light-emitting device including a single semiconductor light-emitting element.

[0343] Furthermore, since each of the first semiconductor light-emitting element 30A and the second semiconductor light-emitting element 30B includes multiple (four in the first embodiment) light-emitting portions 33, the average output power of the laser light can be increased compared to a semiconductor light-emitting device including one semiconductor light-emitting element including one light-emitting portion.

[0344] [Effects] The semiconductor light-emitting device 10 of the third embodiment has the following effects: (3-1) Each of the first switching element 411 and the second switching element 412 includes a source electrode 41S, a drain electrode 41D, and a gate electrode 41G formed on the back surface of the element. The source electrode 41S, the drain electrode 41D, and the gate electrode 41G of each of the first switching element 411 and the second switching element 412 are mounted on a plurality of front surface electrodes 28A.

[0345] With this configuration, no wires are used to electrically connect the source electrode 41S, the drain electrode 41D, and the gate electrode 41G of the first switching element 411 to the plurality of surface electrodes 28A, thereby reducing the inductance of the loop-shaped first current path formed by the first semiconductor light emitting element 30A, the first switching element 411, and the first capacitor 421. Furthermore, no wires are used to electrically connect the source electrode 41S, the drain electrode 41D, and the gate electrode 41G of the second switching element 412 to the plurality of surface electrodes 28A, thereby reducing the inductance of the loop-shaped second current path formed by the second semiconductor light emitting element 30B, the second switching element 412, and the second capacitor 422.

[0346] (3-2) The first switching element 411 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 412 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.

[0347] According to this configuration, the direction (X direction) orthogonal to the arrangement direction (Y direction) of the first semiconductor light emitting element 30A, the first switching element 411, and the first capacitor 421 corresponds to the longitudinal direction of the first switching element 411. This reduces the distance in the Y direction between the first semiconductor light emitting element 30A and the first capacitor 421 compared to a configuration in which the arrangement direction corresponds to the longitudinal direction of the first switching element 411. This reduces the length of the loop-shaped first current path formed by the first semiconductor light emitting element 30A, the first switching element 411, and the first capacitor 421. Furthermore, the direction (X direction) orthogonal to the arrangement direction (Y direction) of the second semiconductor light emitting element 30B, the second switching element 412, and the second capacitor 422 corresponds to the longitudinal direction of the second switching element 412. This reduces the distance in the Y direction between the second semiconductor light emitting element 30B and the second capacitor 422 compared to a configuration in which the arrangement direction corresponds to the longitudinal direction of the second switching element 412. This allows the loop-shaped second current path formed by the second semiconductor light emitting element 30B, the second switching element 412, and the second capacitor 422 to be shortened.

[0348] (3-3) Horizontal transistors of the same configuration are used for the first switching element 411 and the second switching element 412. 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.

[0349] 20 to 26, 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 mainly in the number of drive circuits, gate driver ICs, and capacitors. Below, differences from the semiconductor light emitting device 10 according to the third embodiment will be described in detail, and components common to the third embodiment will be denoted by the same reference numerals and will not be described again.

[0350] FIG. 20 shows a schematic planar structure of a semiconductor light-emitting device 10 according to the fourth embodiment. FIG. 21 shows an enlarged schematic planar structure of the semiconductor light-emitting device 10 of FIG. 20 , showing a portion between the imaginary center line VC and the first substrate side surface 23. FIG. 22 shows an enlarged schematic planar structure of the semiconductor light-emitting device 10 of FIG. 20 , showing a portion between the imaginary center line VC and the second substrate side surface 24. FIG. 23 shows a schematic back surface structure of the semiconductor light-emitting device 10 of FIG. 20 . FIG. 24 shows a schematic planar structure of the front surface intermediate electrode 28C of the semiconductor light-emitting device 10 of FIG. 20 . FIG. 25 shows a schematic planar structure of the back surface intermediate electrode 28D of the semiconductor light-emitting device 10 of FIG. 20 . FIG. 26 shows a schematic circuit configuration of a light-emitting system 800 including the semiconductor light-emitting device 10 of FIG. 20 . Note that in FIGS. 20 to 22 , openings in the front surface resist 29A are indicated by two-dot chain lines. In FIG. 23 , openings in the back surface resist 29B are indicated by two-dot chain lines.

[0351] 20 , the semiconductor light emitting device 10 of the fourth embodiment includes first to fourth semiconductor light emitting elements 30A to 30D, first to fourth drive circuits 40A to 40D, gate driver ICs 805A to 805D, and capacitors 808A to 808D. On the other hand, the semiconductor light emitting device 10 of the fourth embodiment does not include protection diodes that protect the first to fourth semiconductor light emitting elements 30A to 30D.

[0352] The first to fourth switching elements 411 to 414 of the first to fourth drive circuits 40A to 40D use horizontal transistors, as in the third embodiment. However, the first to fourth switching elements 411 to 414 of the fourth embodiment have fewer drain electrodes 41D and source electrodes 41S than the switching elements 411 and 412 of the third embodiment (see FIG. 14). Therefore, the size of the first to fourth switching elements 411 to 414 of the fourth embodiment is smaller than the size of the switching elements 411 and 412 of the third embodiment.

[0353] The gate driver IC 805A is configured to drive the first switching element 411. The capacitor 808A is electrically connected to the gate driver IC 805A. The gate driver IC 805B is configured to drive the second switching element 412. The capacitor 808B is electrically connected to the gate driver IC 805B. The gate driver IC 805C is configured to drive the third switching element 413. The capacitor 808C is electrically connected to the gate driver IC 805C. The gate driver IC 805D is configured to drive the fourth switching element 414. The capacitor 808D is electrically connected to the gate driver IC 805D. Due to these changes in the configuration of the semiconductor light emitting device 10, 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.

[0354] (Surface Electrodes) As shown in Figures 20 to 22, surface electrodes 28A formed on substrate surface 21 include first surface electrodes 201A to 201D, second surface electrodes 202A to 202D, third surface electrode 203, fourth surface electrodes 204A to 204D, fifth surface electrodes 205A to 205D, sixth surface electrodes 206A to 206D, seventh surface electrodes 207A to 207D, eighth surface electrodes 208A, 208B, ninth surface electrodes 209A, 209B, and tenth surface electrodes 210A, 210B. The first surface electrodes 201A to 201D, the second surface electrodes 202A to 202D, the third surface electrode 203, the fourth surface electrodes 204A to 204D, the fifth surface electrodes 205A to 205D, the sixth surface electrodes 206A to 206D, the seventh surface electrodes 207A to 207D, the eighth surface electrodes 208A, 208B, the ninth surface electrodes 209A, 209B, and the tenth surface electrodes 210A, 210B are arranged at a distance from each other.

[0355] The first surface electrode 201A is an electrode on which the first semiconductor light-emitting element 30A is mounted, the first surface electrode 201B is an electrode on which the second semiconductor light-emitting element 30B is mounted, the first surface electrode 201C is an electrode on which the third semiconductor light-emitting element 30C is mounted, and the first surface electrode 201D is an electrode on which the fourth semiconductor light-emitting element 30D is mounted.

[0356] The second surface electrode 202A, the third surface electrode 203, the fourth surface electrode 204A, and the fifth surface electrode 205A are electrodes on which the first drive circuit 40A is mounted. The fifth surface electrode 205A, the sixth surface electrode 206A, and the seventh surface electrode 207A are electrodes on which the gate driver IC 805A is mounted.

[0357] The second surface electrode 202B, the third surface electrode 203, the fourth surface electrode 204B, and the fifth surface electrode 205B are electrodes on which the second drive circuit 40B is mounted. The fifth surface electrode 205B, the sixth surface electrode 206B, and the seventh surface electrode 207B are electrodes on which the gate driver IC 805B is mounted.

[0358] The second surface electrode 202C, the third surface electrode 203, the fourth surface electrode 204C, and the fifth surface electrode 205C are electrodes on which a third drive circuit 40C is mounted. The fifth surface electrode 205C, the sixth surface electrode 206C, and the seventh surface electrode 207C are electrodes on which a gate driver IC 805C is mounted.

[0359] The second surface electrode 202D, the third surface electrode 203, the fourth surface electrode 204D, and the fifth surface electrode 205D are electrodes on which a fourth drive circuit 40D is mounted. The fifth surface electrode 205D, the sixth surface electrode 206D, and the seventh surface electrode 207D are electrodes on which a gate driver IC 805D is mounted.

[0360] The first surface electrodes 201A to 201D are arranged at positions adjacent to the third substrate side surface 25 in the Y direction. The first surface electrodes 201A to 201D are arranged at the same positions as each other in the Y direction and spaced apart from each other in the X direction. The first surface electrodes 201A and 201C are arranged closer to the first substrate side surface 23 than the imaginary center line VC. The first surface electrode 201A is arranged closer to the imaginary center line VC than the first surface electrode 201C. The first surface electrodes 201B and 201D are arranged closer to the second substrate side surface 24 than the imaginary center line VC. The first surface electrode 201B is arranged closer to the imaginary center line VC than the first surface electrode 201D. The first surface electrodes 201A to 201D are 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.

[0361] The second surface electrodes 202A to 202D are arranged around the first surface electrodes 201A to 201D so as to surround the first surface electrodes 201A to 201D. As shown in Fig. 21 , the second surface electrodes 202A and 202C are arranged closer to the first substrate side surface 23 than the imaginary center line VC. The second surface electrode 202A is arranged closer to the imaginary center line VC than the second surface electrode 202C.

[0362] The second surface electrode 202A is formed in a substantially vertical trapezoidal shape whose dimension in the X direction increases with increasing distance from the first surface electrode 201A in the Y direction. In a plan view, the side of the second surface electrode 202A closest to the imaginary center line VC extends along the Y direction. In a plan view, the second surface electrode 202A includes an inclined side that inclines toward the first substrate side surface 23 with increasing distance from the first surface electrode 201A in the Y direction. In a plan view, the side of the second surface electrode 202A closest to the first surface electrode 201A extends along the X direction. The side of the second surface electrode 202A closest to the first surface electrode 201A faces the first surface electrode 201A in the Y direction and is positioned adjacent to the first surface electrode 201A in the Y direction.

[0363] The second surface electrode 202C includes a recessed portion that is recessed so as to avoid the first surface electrode 201C. Therefore, the second surface electrode 202C is formed so as to surround the first surface electrode 201C from the first substrate side surface 23 and the fourth substrate side surface 26. The second surface electrode 202C includes an inclined side that is inclined parallel to the inclined side of the second surface electrode 202A.

[0364] 22, the second surface electrodes 202B and 202D are disposed closer to the second substrate side surface 24 than the imaginary center line VC. The second surface electrode 202B is disposed closer to the imaginary center line VC than the second surface electrode 202D.

[0365] The second surface electrode 202B is formed in a substantially vertical trapezoidal shape whose dimension in the X direction increases with increasing distance from the first surface electrode 201A in the Y direction. The second surface electrode 202B is, for example, symmetrical to the second surface electrode 202A with respect to the imaginary center line VC.

[0366] The second surface electrode 202D includes a recessed portion recessed so as to avoid the first surface electrode 201 D. The second surface electrode 202D is, for example, in line symmetry with the second surface electrode 202C with respect to the imaginary center line VC.

[0367] 20 , the third surface electrode 203 is formed to surround the second surface electrodes 202A to 202D. The third surface electrode 203 is formed over most of the substrate surface 21. The third surface electrode 203 includes recesses that accommodate the first to fourth semiconductor light emitting elements 30A to 30D and the second surface electrodes 202A to 202D. The recesses open toward the third substrate side surface 25. The third surface electrode 203 includes four openings. The fourth to seventh surface electrodes 204A to 207A, the fourth to seventh surface electrodes 204B to 207B, the fourth to seventh surface electrodes 204C to 207C, and the fourth to seventh surface electrodes 204D to 207D are dispersedly arranged in the four openings.

[0368] As shown in FIG. 21 , the fourth to seventh surface electrodes 204A to 207A are arranged closer to the fourth substrate side surface 26 than the second surface electrode 202A. The fourth surface electrode 204A and the fifth surface electrode 205A are arranged in positions overlapping with the second surface electrode 202A when viewed from the Y direction. The fourth surface electrode 204A is arranged in a position overlapping with the second surface electrode 202A when viewed from the Y direction. The fourth surface electrode 204A has an elliptical shape with the Y direction as its longitudinal direction and the X direction as its lateral direction. The fifth surface electrode 205A is arranged closer to the first substrate side surface 23 than the fourth surface electrode 204A. The fifth surface electrode 205A extends in the X direction.

[0369] The sixth surface electrode 206A and the seventh surface electrode 207A are arranged closer to the first substrate side surface 23 in the X direction than the second surface electrode 202A. The sixth surface electrode 206A and the seventh surface electrode 207A are arranged at positions overlapping with the second surface electrode 202C when viewed from the Y direction. The sixth surface electrode 206A and the seventh surface electrode 207A are arranged closer to the first substrate side surface 23 than the fifth surface electrode 205A. The sixth surface electrode 206A and the seventh surface electrode 207A are arranged at the same position in the X direction and spaced apart from each other in the Y direction. The sixth surface electrode 206A is arranged closer to the fourth substrate side surface 26 than the seventh surface electrode 207A. The sixth surface electrode 206A is arranged at a position adjacent to the fifth surface electrode 205A in the X direction.

[0370] The fourth to seventh surface electrodes 204C to 207C are arranged closer to the first substrate side surface 23 than the second surface electrode 202C. The fourth surface electrode 204C and the fifth surface electrode 205C are arranged in a position overlapping with the second surface electrode 202C when viewed from the X direction. The fourth surface electrode 204C is arranged closer to the fourth substrate side surface 26 in the Y direction than the first surface electrode 201C. The fourth surface electrode 204C has an elliptical shape with the X direction as its longitudinal direction and the Y direction as its lateral direction. The fifth surface electrode 205C is arranged closer to the fourth substrate side surface 26 than the fourth surface electrode 204C. The fifth surface electrode 205C extends in the Y direction.

[0371] The sixth surface electrode 206C and the seventh surface electrode 207C are arranged closer to the fourth substrate side surface 26 than the second surface electrode 202C in the Y direction. The sixth surface electrode 206C and the seventh surface electrode 207C are arranged closer to the fourth substrate side surface 26 than the fifth surface electrode 205C. The sixth surface electrode 206C and the seventh surface electrode 207C are arranged at the same position in the Y direction and spaced apart from each other in the X direction. The sixth surface electrode 206C is arranged closer to the imaginary center line VC than the seventh surface electrode 207C. The seventh surface electrode 207C is arranged in a position adjacent to the fifth surface electrode 205C in the Y direction.

[0372] 22, the fourth to seventh surface electrodes 204B to 207B are arranged closer to the fourth substrate side surface 26 than the second surface electrode 202B. The shapes and arrangement of the fourth surface electrode 204B, fifth surface electrode 205B, sixth surface electrode 206B, and seventh surface electrode 207B are the same as those of the fourth surface electrode 204C, fifth surface electrode 205C, sixth surface electrode 206C, and seventh surface electrode 207C rotated 90° clockwise.

[0373] The fourth to seventh surface electrodes 204D to 207D are arranged closer to the second substrate side surface 24 than the second surface electrode 202D. The shapes and arrangement of the fourth surface electrode 204D, fifth surface electrode 205D, sixth surface electrode 206D, and seventh surface electrode 207D are the same as those of the fourth surface electrode 204A, fifth surface electrode 205A, sixth surface electrode 206A, and seventh surface electrode 207A rotated 90 degrees clockwise.

[0374] 20 , the eighth surface electrodes 208A and 208B, the ninth surface electrodes 209A and 209B, and the tenth surface electrodes 210A and 210B are arranged adjacent to the fourth substrate side surface 26 in the Y direction. The eighth surface electrode 208A, the ninth surface electrode 209A, and the tenth surface electrode 210A are arranged closer to the first substrate side surface 23 than the imaginary center line VC. The eighth surface electrode 208A, the ninth surface electrode 209A, and the tenth surface electrode 210A are arranged at the same position as each other in the Y direction and spaced apart from each other in the X direction. The eighth surface electrode 208A, the ninth surface electrode 209A, and the tenth surface electrode 210A are arranged in this order from the imaginary center line VC toward the first substrate side surface 23. The eighth surface electrode 208B, the ninth surface electrode 209B, and the tenth surface electrode 210B are arranged closer to the second substrate side surface 24 than the imaginary center line VC. The eighth surface electrode 208B, the ninth surface electrode 209B, and the tenth surface electrode 210B are arranged at the same position as each other in the Y direction and spaced apart from each other in the X direction. The eighth surface electrode 208B, the ninth surface electrode 209B, and the tenth surface electrode 210B are arranged in this order from the imaginary center line VC toward the second substrate side surface 24. A part of the third surface electrode 203 is interposed between the eighth surface electrode 208A and the eighth surface electrode 208B in the X direction.

[0375] The eighth surface electrodes 208A and 208B, the ninth surface electrodes 209A and 209B, and the tenth surface electrodes 210A and 210B are formed, for example, in a square shape, and are, for example, the same size as one another.

[0376] (Rear surface electrode) As shown in FIG. 23, the rear surface electrode 28B includes first rear surface electrodes 211A to 211D, second rear surface electrodes 212A to 212D, third rear surface electrodes 213A to 213C, fourth rear surface electrodes 214A, 214B, fifth rear surface electrodes 215A, 215B, sixth rear surface electrodes 216A, 216B, seventh rear surface electrodes 217A, 217B, eighth rear surface electrodes 218A, 218B, and ninth rear surface electrodes 219A, 219B. The first back-surface electrodes 211A to 211D, the second back-surface electrodes 212A to 212D, the third back-surface electrodes 213A to 213C, the fourth back-surface electrodes 214A and 214B, the fifth back-surface electrodes 215A and 215B, the sixth back-surface electrodes 216A and 216B, the seventh back-surface electrodes 217A and 217B, the eighth back-surface electrodes 218A and 218B, and the ninth back-surface electrodes 219A and 219B are arranged spaced apart from one another. The second back-surface electrodes 212A to 212D, the third back-surface electrodes 213A to 213C, the seventh back-surface electrodes 217A and 217B, the eighth back-surface electrodes 218A and 218B, and the ninth back-surface electrodes 219A and 219B constitute external electrode terminals that are electrically connected to the circuit board 900 when the semiconductor light-emitting device 10 is mounted on the circuit board 900. The first rear surface electrodes 211A to 211D are heat dissipation electrodes for dissipating heat to the outside of the semiconductor light emitting device 10.

[0377] The first back surface electrode 211A is an electrode that electrically connects both the first surface electrode 201A and the fourth surface electrode 204A (see FIG. 20 for both). The first back surface electrode 211B is an electrode that electrically connects both the first surface electrode 201B and the fourth surface electrode 204B (see FIG. 20 for both). The first back surface electrode 211C is an electrode that electrically connects both the first surface electrode 201C and the fourth surface electrode 204C (see FIG. 20 for both). The first back surface electrode 211D is an electrode that electrically connects both the first surface electrode 201D and the fourth surface electrode 204D (see FIG. 20 for both).

[0378] The first back surface electrodes 211A and 211C are arranged closer to the first substrate side surface 23 than the imaginary center line VC. The first back surface electrode 211C is arranged on the opposite side of the imaginary center line VC from the first back surface electrode 211A. The first back surface electrodes 211B and 211D are arranged closer to the second substrate side surface 24 than the imaginary center line VC. The first back surface electrode 211D is arranged on the opposite side of the imaginary center line VC from the first back surface electrode 211B. The first back surface electrodes 211A and 211B are arranged dispersedly on both sides of the imaginary center line VC so as to be adjacent to the imaginary center line VC in the X direction.

[0379] The first back surface electrodes 211A and 211B extend in the Y direction. The first back surface electrode 211A is formed so as to overlap both the first surface electrode 201A and the fourth surface electrode 204A in a plan view. The first back surface electrode 211B is arranged so as to overlap both the first surface electrode 201B and the fourth surface electrode 204B in a plan view. In one example, the first back surface electrode 211A and the first back surface electrode 211B are in an axisymmetric relationship with respect to the imaginary center line VC.

[0380] The first back surface electrodes 211C and 211D extend in the X direction. The first back surface electrode 211C is formed so as to overlap both the first surface electrode 201C and the fourth surface electrode 204C in a plan view. The first back surface electrode 211D is arranged so as to overlap both the first surface electrode 201D and the fourth surface electrode 204D in a plan view. In one example, the first back surface electrode 211C and the first back surface electrode 211D are in an axisymmetric relationship with respect to the imaginary center line VC.

[0381] The second rear surface electrode 212A is an electrode electrically connected to the second front surface electrode 202A. The second rear surface electrode 212B is an electrode electrically connected to the second front surface electrode 202B. The second rear surface electrode 212C is an electrode electrically connected to the second front surface electrode 202C. The second rear surface electrode 212D is an electrode electrically connected to the second front surface electrode 202D.

[0382] The second back surface electrode 212A is disposed closer to the first substrate side surface 23 than the first back surface electrode 211A. The second back surface electrode 212A includes a first portion adjacent to the first back surface electrode 211A in the X direction, a second portion extending in the Y direction at a position spaced apart from the first back surface electrode 211A in the X direction relative to the first portion, a connecting portion connecting the first portion and the second portion, and a square-shaped third portion at an end of the second portion opposite the connecting portion. The third portion is disposed adjacent to the fourth substrate side surface 26 in the Y direction. The first portion is disposed at a position overlapping the second surface electrode 202A in a plan view.

[0383] The second back surface electrode 212B is disposed closer to the second substrate side surface 24 than the first back surface electrode 211B. In one example, the second back surface electrode 212B is in a line-symmetric relationship with the second back surface electrode 212A with respect to the imaginary center line VC. A first portion of the second back surface electrode 212B adjacent to the first back surface electrode 211B in the X direction is disposed at a position overlapping with the second surface electrode 202B in a plan view.

[0384] The second back surface electrode 212C is arranged closer to the fourth substrate side surface 26 than the first back surface electrode 211C. The second back surface electrode 212C includes a first portion adjacent to the first back surface electrode 211C in the Y direction, a second portion extending in the X direction at a position separated from the first back surface electrode 211C in the Y direction relative to the first portion, a connecting portion connecting the first portion and the second portion, and a square-shaped third portion at the end of the second portion opposite the connecting portion. The third portion is arranged adjacent to the first substrate side surface 23 in the X direction. The first portion is arranged at a position overlapping with the second surface electrode 202C in a plan view.

[0385] The second back surface electrode 212D is disposed closer to the fourth substrate side surface 26 than the first back surface electrode 211D. In one example, the second back surface electrode 212D is in a line-symmetric relationship with the second back surface electrode 212C with respect to the imaginary center line VC. A first portion of the second back surface electrode 212D adjacent to the first back surface electrode 211D in the Y direction is disposed at a position overlapping with the second surface electrode 202D in a plan view.

[0386] Each of the third back surface electrodes 213A to 213C is an electrode electrically connected to the third front surface electrode 203. The third back surface electrode 213A is disposed at the center in the X direction of the substrate back surface 22. The third back surface electrode 213B is disposed closer to the first substrate side surface 23 and the third substrate side surface 25 than the third back surface electrode 213A. The third back surface electrode 213C is disposed closer to the second substrate side surface 24 and the third substrate side surface 25 than the third back surface electrode 213A.

[0387] The third back surface electrode 213A is formed to surround both of the first back surface electrodes 211A and 211B from both sides in the X direction and from the fourth substrate side surface 26 side. The third back surface electrode 213A is formed in a substantially U-shape that opens toward the third substrate side surface 25. A first portion of the third back surface electrode 213A that surrounds the first back surface electrode 211A from the first substrate side surface 23 is located between the first back surface electrode 211A and the second portion of the second back surface electrode 212A in the X direction. A second portion of the third back surface electrode 213A that surrounds the first back surface electrode 211B from the second substrate side surface 24 is located between the first back surface electrode 211B and the second portion of the second back surface electrode 212B in the X direction.

[0388] The third back surface electrode 213B is formed to surround the first back surface electrode 211C from the first substrate side surface 23 and the fourth substrate side surface 26. The third back surface electrode 213B is formed in a substantially L-shape. The portion of the third back surface electrode 213B that surrounds the first back surface electrode 211C from the fourth substrate side surface 26 is disposed between the first back surface electrode 211C and the second portion of the second back surface electrode 212C in the Y direction.

[0389] The third back surface electrode 213C is formed to surround the first back surface electrode 211D from the second substrate side surface 24 and the fourth substrate side surface 26. The third back surface electrode 213C is formed in a substantially L-shape. The portion of the third back surface electrode 213C that surrounds the first back surface electrode 211D from the fourth substrate side surface 26 is disposed between the first back surface electrode 211D and the second portion of the second back surface electrode 212D in the Y direction. In one example, the third back surface electrode 213B and the third back surface electrode 213C are in an axisymmetric relationship with respect to the imaginary center line VC. Each of the third back surface electrodes 213A to 213C is formed to overlap with the third surface electrode 203 in a plan view.

[0390] In the area surrounded by the second back surface electrodes 212A, 212C, the first substrate side surface 23 and the fourth substrate side surface 26, the fourth back surface electrodes 214A, 214C, the fifth back surface electrodes 215A, 215C, the sixth back surface electrode 216A, the seventh back surface electrode 217A, the eighth back surface electrode 218A and the ninth back surface electrode 219A are arranged.

[0391] The fourth back surface electrode 214A is an electrode electrically connected to the sixth surface electrode 206A (see FIG. 20 ), and the fourth back surface electrode 214C is an electrode electrically connected to the sixth surface electrode 206C (see FIG. 20 ). The fifth back surface electrode 215A is an electrode electrically connected to the seventh surface electrode 207A (see FIG. 20 ), and the fifth back surface electrode 215C is an electrode electrically connected to the seventh surface electrode 207C (see FIG. 20 ). The sixth back surface electrode 216A is an electrode electrically connected to the third surface electrode 203 (see FIG. 20 ). The seventh back surface electrode 217A is an electrode electrically connected to the eighth surface electrode 208A (see FIG. 20 ), the eighth back surface electrode 218A is an electrode electrically connected to the ninth surface electrode 209A (see FIG. 20 ), and the ninth back surface electrode 219A is an electrode electrically connected to the tenth surface electrode 210A (see FIG. 20 ).

[0392] The fourth back-surface electrodes 214A, 214C and the fifth back-surface electrodes 215A, 215C are individually disposed in a plurality of openings formed in the sixth back-surface electrode 216A. In one example, each opening is formed in a circular shape. In one example, the fourth back-surface electrodes 214A, 214C and the fifth back-surface electrodes 215A, 215C are each formed in a circular shape in a plan view.

[0393] The fourth back surface electrode 214A is arranged closer to the fourth substrate side surface 26 than the fifth back surface electrode 215A. The fourth back surface electrode 214A is arranged at a position overlapping with the sixth surface electrode 206A in a plan view. The fifth back surface electrode 215A is arranged at a position overlapping with the seventh surface electrode 207A in a plan view. The fourth back surface electrode 214C and the fifth back surface electrode 215C are arranged closer to the first substrate side surface 23 than the fourth back surface electrode 214A and the fifth back surface electrode 215A. The fifth back surface electrode 215C is arranged closer to the first substrate side surface 23 than the fourth back surface electrode 214C. The fourth back surface electrode 214C is arranged at a position overlapping with the sixth surface electrode 206C in a plan view. The fifth back surface electrode 215C is arranged at a position overlapping with the seventh surface electrode 207C in a plan view.

[0394] The seventh, eighth, and ninth back surface electrodes 217A, 218A, and 219A are arranged in an area surrounded by the sixth back surface electrode 216A, the first substrate side surface 23, and the fourth substrate side surface 26. The seventh, eighth, and ninth back surface electrodes 217A, 218A, and 219A are arranged at the same positions in the Y direction and spaced apart from each other in the X direction. The seventh, eighth, and ninth back surface electrodes 217A, 218A, and 219A are arranged in this order from the imaginary center line VC toward the first substrate side surface 23. The seventh, eighth, and ninth back surface electrodes 217A, 218A, and ninth back surface electrodes 219A are formed in a square shape in a plan view.

[0395] The fourth back-surface electrodes 214B and 214D, the fifth back-surface electrodes 215B and 215D, the sixth back-surface electrode 216B, the seventh back-surface electrode 217B, the eighth back-surface electrode 218B, and the ninth back-surface electrode 219B are arranged in the region surrounded by the second back-surface electrodes 212B and 212D and the second and fourth substrate side surfaces 24 and 26. Here, the fourth back-surface electrodes 214A to 214D, the fifth back-surface electrodes 215A to 215D, and the sixth back-surface electrodes 216A and 216B are covered with a back-surface resist 29B (see FIG. 4), and therefore do not constitute external electrode terminals.

[0396] The fourth back surface electrode 214B is an electrode electrically connected to the sixth surface electrode 206B (see FIG. 20 ), and the fourth back surface electrode 214D is an electrode electrically connected to the sixth surface electrode 206D (see FIG. 20 ). The fifth back surface electrode 215B is an electrode electrically connected to the seventh surface electrode 207B (see FIG. 20 ), and the fifth back surface electrode 215D is an electrode electrically connected to the seventh surface electrode 207D (see FIG. 20 ). The seventh back surface electrode 217B is an electrode electrically connected to the eighth surface electrode 208B (see FIG. 20 ), the eighth back surface electrode 218B is an electrode electrically connected to the ninth surface electrode 209B (see FIG. 20 ), and the ninth back surface electrode 219B is an electrode electrically connected to the tenth surface electrode 210B (see FIG. 20 ).

[0397] The fourth back-surface electrodes 214B, 214D and the fifth back-surface electrodes 215B, 215D are individually disposed in a plurality of openings formed in the sixth back-surface electrode 216B. In one example, each opening is formed in a circular shape. In one example, the fourth back-surface electrodes 214B, 214D and the fifth back-surface electrodes 215B, 215D are each formed in a circular shape in a plan view.

[0398] The fifth back surface electrode 215B is arranged closer to the fourth substrate side surface 26 than the fourth back surface electrode 214B. The fourth back surface electrode 214B is arranged at a position overlapping with the sixth surface electrode 206B in a plan view. The fifth back surface electrode 215B is arranged at a position overlapping with the seventh surface electrode 207B in a plan view. The fourth back surface electrode 214D and the fifth back surface electrode 215D are arranged closer to the second substrate side surface 24 than the fourth back surface electrode 214B and the fifth back surface electrode 215B. The fourth back surface electrode 214D is arranged closer to the second substrate side surface 24 than the fifth back surface electrode 215D. The fourth back surface electrode 214D is arranged at a position overlapping with the sixth surface electrode 206D in a plan view. The fifth back surface electrode 215D is arranged at a position overlapping with the seventh surface electrode 207D in a plan view.

[0399] The seventh, eighth, and ninth back surface electrodes 217B, 218B, and 219B are arranged in an area surrounded by the sixth back surface electrode 216B, the second substrate side surface 24, and the fourth substrate side surface 26. The seventh, eighth, and ninth back surface electrodes 217B, 218B, and 219B are arranged at the same positions in the Y direction and spaced apart from each other in the X direction. The seventh, eighth, and ninth back surface electrodes 217B, 218B, and 219B are arranged in this order from the imaginary center line VC toward the second substrate side surface 24. The seventh, eighth, and ninth back surface electrodes 217B, 218B, and ninth back surface electrodes 219B are formed in a square shape in a plan view.

[0400] 24 , the surface-side intermediate electrode 28C includes first intermediate electrodes 221A to 221D, second intermediate electrodes 222A to 222D, third intermediate electrode 223, fourth intermediate electrodes 224A to 224D, fifth intermediate electrodes 225A and 225B, sixth intermediate electrodes 226A and 226B, and seventh intermediate electrodes 227A and 227B. The first intermediate electrodes 221A to 221D, second intermediate electrodes 222A to 222D, third intermediate electrode 223, fourth intermediate electrodes 224A to 224D, fifth intermediate electrodes 225A and 225B, sixth intermediate electrodes 226A and 226B, and seventh intermediate electrodes 227A and 227B are arranged spaced apart from one another.

[0401] The first intermediate electrodes 221A to 221D have the same shape, size, and arrangement as the first rear surface electrodes 211A to 211D. The first intermediate electrode 221A is an electrode electrically connected to the first front surface electrode 201A and the fourth front surface electrode 204A (see FIG. 20) and the first rear surface electrode 211A (see FIG. 23). The first intermediate electrode 221B is an electrode electrically connected to the first front surface electrode 201B and the fourth front surface electrode 204B (see FIG. 20) and the first rear surface electrode 211B (see FIG. 23). The first intermediate electrode 221C is an electrode electrically connected to the first front surface electrode 201C and the fourth front surface electrode 204C (see FIG. 20) and the first rear surface electrode 211C (see FIG. 23). The first intermediate electrode 221D is an electrode electrically connected to the first surface electrode 201D and the fourth surface electrode 204D (see FIG. 20) and the first back surface electrode 211D (see FIG. 23).

[0402] The second intermediate electrode 222A is an electrode electrically connected to the second surface electrode 202A (see FIG. 20 ) and the second back surface electrode 212A (see FIG. 23 ). The second intermediate electrode 222A is disposed closer to the first substrate side surface 23 than the first intermediate electrode 221A and adjacent to the first intermediate electrode 221A in the X direction. The second intermediate electrode 222A is disposed at a position overlapping both the second surface electrode 202A and the first portion of the second back surface electrode 212A in a plan view.

[0403] The second intermediate electrode 222B is an electrode electrically connected to the second surface electrode 202B (see FIG. 20 ) and the second back surface electrode 212B (see FIG. 23 ). The second intermediate electrode 222B is disposed closer to the second substrate side surface 24 than the first intermediate electrode 221B and adjacent to the first intermediate electrode 221B in the X direction. The second intermediate electrode 222B is disposed in a position overlapping both the second surface electrode 202B and the first portion of the second back surface electrode 212B in a plan view. The second intermediate electrodes 222A and 222B have an oval shape with the X direction as the longitudinal direction and the Y direction as the lateral direction.

[0404] The second intermediate electrode 222C is an electrode electrically connected to the second surface electrode 202C (see FIG. 20) and the second back surface electrode 212C (see FIG. 23). The second intermediate electrode 222C is disposed closer to the fourth substrate side surface 26 than the first intermediate electrode 221C and adjacent to the first intermediate electrode 221C in the Y direction. The second intermediate electrode 222C is disposed at a position overlapping both the second surface electrode 202C and the first portion of the second back surface electrode 212C in a plan view.

[0405] The second in...

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, electrically connected to the plurality of surface electrodes and constituting a mounting surface of the semiconductor light-emitting device; a first semiconductor light-emitting element and a second semiconductor light-emitting element each including an element surface electrode and an element back surface electrode; a first drive circuit for driving the first semiconductor light-emitting element; and a second drive circuit for driving the second semiconductor light-emitting element, wherein the element back surface electrode of the first semiconductor light-emitting element, the element back surface electrode of the second 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 described in claim 1, wherein the first drive circuit includes a first switching element that controls the drive of the first semiconductor light emitting element and a first capacitor that supplies current to the first semiconductor light emitting element, and the second drive circuit includes a second switching element that controls the drive of the second semiconductor light emitting element and a second capacitor that supplies current to the second semiconductor light emitting element.

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

5. Each of the first switching element and the second switching element includes a drain electrode, a source electrode, and a gate electrode, each of the first capacitor and the second capacitor includes a first electrode and a second electrode, the element front surface electrode and the element back surface electrode of the first semiconductor light emitting element constitute a first anode electrode and a first cathode electrode, the element front surface electrode and the element back surface electrode of the second semiconductor light emitting element constitute a second anode electrode and a second cathode 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 first switching element is electrically connected to the first anode electrode, the first cathode electrode is electrically connected to the second electrode of the first capacitor, the drain electrode of the second switching element is electrically connected to the first electrode of the second capacitor, the source electrode of the second switching element is electrically connected to the second anode electrode, and the second cathode electrode is electrically connected to the second electrode of the second capacitor.

4. The semiconductor light emitting device according to claim 2.

6. The semiconductor light-emitting device of claim 5, wherein, when viewed from the thickness direction of the substrate, the first semiconductor light-emitting element and the first switching element 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 first semiconductor light-emitting element and the first capacitor in the first direction, when viewed from the thickness direction, the second semiconductor light-emitting element and the second switching element 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 second semiconductor light-emitting element and the second capacitor in the first direction.

7. The semiconductor light-emitting device as described in claim 6, wherein the first switching element is arranged closer to the first semiconductor light-emitting element than the first capacitor in the first direction, and the second switching element is arranged closer to the second semiconductor light-emitting element than the second capacitor in the first direction.

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

9. Each of the first switching element and the second switching element includes a drain electrode, a source electrode, and a gate electrode, each of the first capacitor and the second capacitor includes a first electrode and a second electrode, the element front surface electrode and the element back surface electrode of the first semiconductor light emitting element constitute a first anode electrode and a first cathode electrode, the element front surface electrode and the element back surface electrode of the second semiconductor light emitting element constitute a second anode electrode and a second cathode electrode, the drain electrode of the first switching element is electrically connected to the first cathode electrode, the source electrode of the first switching element is electrically connected to the second electrode of the first capacitor, the first anode electrode is electrically connected to the first electrode of the first capacitor, the drain electrode of the second switching element is electrically connected to the second cathode electrode, the source electrode of the second switching element is electrically connected to the second electrode of the second capacitor, and the second anode electrode is electrically connected to the first electrode of the second capacitor.

4. The semiconductor light emitting device according to claim 2.

10. A semiconductor light-emitting device as described in claim 2 or 4, wherein, when viewed from the thickness direction of the substrate, the first semiconductor light-emitting element and the first switching element are arranged at a distance from each other in a first direction, when viewed from the thickness direction, the first capacitor is arranged between the first semiconductor light-emitting element and the first switching element in the first direction, when viewed from the thickness direction, the second semiconductor light-emitting element and the second switching element are arranged at a distance from each other in the first direction, and when viewed from the thickness direction, the second capacitor is arranged between the second semiconductor light-emitting element and the second switching element in the first direction.

11. The semiconductor light-emitting device described in claim 10, wherein the first capacitor is arranged closer to the first switching element than the first semiconductor light-emitting element in the first direction, and the second capacitor is arranged closer to the second switching element than the second semiconductor light-emitting element in the first direction.

12. A semiconductor light-emitting device according to any one of claims 2 to 11, 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 second capacitors are connected in parallel to each other.

13. The semiconductor light-emitting device of claim 12, wherein, when viewed from the thickness direction of the substrate, the first semiconductor light-emitting element, the first switching element, and the first capacitor are arranged at a distance from each other in a first direction, when viewed from the thickness direction, the second semiconductor light-emitting element, the second switching element, and the second capacitor are arranged at a distance from each other in the first direction, a direction perpendicular to the first direction when viewed from the thickness direction is a second direction, the multiple first capacitors are arranged at a distance from each other in the second direction, and the multiple second capacitors are arranged at a distance from each other in the second direction.

14. The semiconductor light emitting device according to any one of claims 1 to 13, further comprising: a first protection diode connected in anti-parallel to the first semiconductor light emitting element; and a second protection diode connected in anti-parallel to the second semiconductor light emitting element.

15. The semiconductor light emitting device according to any one of claims 1 to 14, further comprising: a third semiconductor light emitting element and a fourth semiconductor light emitting element each including an element front surface electrode and an element back surface electrode; a third drive circuit for driving the third semiconductor light emitting element; and a fourth drive circuit for driving the fourth semiconductor light emitting element, wherein the element back surface electrode of the third semiconductor light emitting element, the element back surface electrode of the fourth semiconductor light emitting element, the third drive circuit, and the fourth drive circuit are mounted on the multiple front surface electrodes.

16. The semiconductor light-emitting device described in claim 15, wherein the first semiconductor light-emitting element and the first drive circuit are arranged at a distance in a first direction, the second semiconductor light-emitting element and the second drive circuit are arranged at a distance in the first direction, a direction perpendicular to the first direction when viewed from the thickness direction of the substrate is defined as a second direction, the third semiconductor light-emitting element and the fourth semiconductor light-emitting element are arranged in the second direction, and the third drive circuit and the fourth drive circuit are arranged in a distributed manner on both sides of the third semiconductor light-emitting element and the fourth semiconductor light-emitting element in the second direction.

17. The semiconductor light-emitting device described in claim 16, wherein the third drive circuit includes a third switching element that controls the drive of the third semiconductor light-emitting element and a third capacitor that supplies current to the third semiconductor light-emitting element, and the fourth drive circuit includes a fourth switching element that controls the drive of the fourth semiconductor light-emitting element and a fourth capacitor that supplies current to the fourth semiconductor light-emitting element.

18. The semiconductor light emitting device according to any one of claims 2 to 13, wherein the first capacitor and the second capacitor are silicon capacitors.

19. The semiconductor light-emitting device of claim 18, wherein, when viewed in a thickness direction of the substrate, the first semiconductor light-emitting element and the first switching element are arranged spaced apart from each other in the first direction; when viewed in the thickness direction, the first capacitor is arranged between the first semiconductor light-emitting element and the first switching element in the first direction; when viewed in the thickness direction, the second semiconductor light-emitting element and the second switching element are arranged spaced apart from each other in the first direction; when viewed in the thickness direction, the second capacitor is arranged between the second semiconductor light-emitting element and the second switching element in the first direction; the first capacitor is arranged closer to the first semiconductor light-emitting element than the first switching element in the first direction; and the second capacitor is arranged closer to the second semiconductor light-emitting element than the second switching element in the first direction.

20. A semiconductor light-emitting device as claimed in any one of claims 1 to 19, comprising: a plurality of intermediate electrodes provided between the plurality of front surface electrodes and the plurality of back surface electrodes in the thickness direction of the substrate; and a plurality of vias provided on the substrate and connecting the plurality of back surface electrodes, the plurality of front surface electrodes, and the plurality of intermediate electrodes; a first current path between the first semiconductor light-emitting element and the first driving circuit being formed by the front surface electrodes, the intermediate electrodes, and the vias; and a second current path between the second semiconductor light-emitting element and the second driving circuit being formed by the front surface electrodes, the intermediate electrodes, and the vias.

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