Semiconductor light emitting device and light source device

Abstract

This semiconductor light emitting device (10) comprises: a wiring board (20); a semiconductor light emitting element (41) arranged on the upper surface (20a) of the wiring board (20); and a cap unit (50) which covers the semiconductor light emitting element (41). The wiring board (20) includes a first substrate, a first metal layer (31) and a second metal layer (32) arranged apart from each other on the first substrate, and spacer layers (30a, 30b) arranged on the first substrate. A joint surface (50b) joined to the wiring board (20) of the cap unit (50) intersects the first metal layer (31) and the second metal layer (32) when viewing the wiring board (20) from the top, and the spacer layers (30a, 30b) are arranged at different positions from the first metal layer (31) and the second metal layer (32) between the joint surface (50b) and the first substrate.

Description

[Technical Field]

[0001] The present disclosure relates to a semiconductor light emitting device and a light source device. [Background technology]

[0002] BACKGROUND ART Semiconductor light emitting devices have been proposed in which a semiconductor light emitting element such as a semiconductor laser element is mounted on a substrate and covered with a cap (see, for example, Patent Documents 1 and 2).

[0003] Patent Documents 1 and 2 propose a structure in which a semiconductor laser element is mounted on a substrate via a submount and a cap is placed on the substrate to cover the semiconductor laser element, with a transparent plate placed on the side of the cap to extract the laser light.

[0004] In Patent Documents 1 and 2, the heat dissipation of the semiconductor laser element is improved by the submount and the substrate, and the semiconductor laser element is hermetically sealed by the cap, thereby improving the reliability of the semiconductor laser element. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 6305668 [Patent Document 2] Japanese Patent Application Publication No. 2019-71331 Summary of the Invention [Problem to be solved by the invention]

[0006] In the structures described in Patent Documents 1 and 2, as the optical output of the semiconductor light-emitting element disposed inside the cap increases, a large current needs to be supplied to the semiconductor light-emitting element. Therefore, it is necessary to use wiring suitable for supplying a large current, i.e., wiring with a large cross-sectional area and low resistance, as the wiring for supplying current to the semiconductor light-emitting element. When such wiring with a large cross-sectional area is disposed on the substrate, a gap is formed between the cap and the substrate because the wiring with a large cross-sectional area is disposed between the cap and the substrate. This makes it difficult to seal the gap between the cap and the substrate. While it is possible to avoid this problem by disposing the wiring inside the substrate, this would complicate the structure of the substrate and increase costs.

[0007] The present disclosure is intended to solve such problems, and aims to provide a semiconductor light-emitting device or the like that has a simplified configuration and can achieve high light output and improved reliability of the semiconductor light-emitting element. [Means for solving the problem]

[0008] In order to solve the above problem, one aspect of a semiconductor light-emitting device according to the present disclosure comprises a wiring substrate, a semiconductor light-emitting element arranged on an upper surface of the wiring substrate, and a cap unit arranged on the upper surface of the wiring substrate and covering the semiconductor light-emitting element, wherein the wiring substrate has a first substrate, a first metal layer and a second metal layer arranged spaced apart from each other on the first substrate, and a spacer layer arranged on the first substrate, and a bonding surface of the cap unit that is bonded to the wiring substrate intersects with the first metal layer and the second metal layer in a top view of the wiring substrate, and the spacer layer is arranged at a different position from the first metal layer and the second metal layer between the bonding surface and the first substrate.

[0009] In addition, the semiconductor light emitting device according to the present disclosure Device In one aspect, the wiring substrate may further have a first insulating layer arranged on the upper surface of the first substrate, and the first metal layer, the second metal layer, and the spacer layer may be arranged on the first insulating layer.

[0010] In addition, the semiconductor light emitting device according to the present disclosure Device In one embodiment, the first substrate may be a metal substrate.

[0011] In addition, the semiconductor light emitting device according to the present disclosure Device In one embodiment, the metal substrate may be made of a flat metal plate.

[0012] In addition, the semiconductor light emitting device according to the present disclosure Device In one aspect, an opening may be formed in the first insulating layer, and the semiconductor light emitting element may be disposed in the opening.

[0013] In addition, the semiconductor light emitting device according to the present disclosure Device In one aspect, the spacer layer may be disposed along the joining surface.

[0014] In addition, the semiconductor light emitting device according to the present disclosure Device In one aspect, the wiring substrate may have a second insulating layer that covers at least a portion of the first metal layer, the second metal layer, and the spacer layer.

[0015] In addition, the semiconductor light emitting device according to the present disclosure Device In one aspect, the spacer layer may be made of a metal material.

[0016] In addition, the semiconductor light emitting device according to the present disclosure Device In one aspect, the spacer layer may be made of the same material as the first metal layer or the second metal layer, and may be electrically connected to the first metal layer or the second metal layer.

[0017] In addition, the semiconductor light emitting device according to the present disclosure Device In one aspect, the cap unit has a rectangular top plate and four side walls connected to the four peripheral sides of the top plate, one of the four side walls being a translucent window having an inorganic translucent plate and an anti-reflection film disposed on the inorganic translucent plate, and light emitted from the semiconductor light-emitting element may pass through the translucent window.

[0018] In addition, the semiconductor light emitting device according to the present disclosure Device In one aspect, the top plate may be transparent.

[0019] In addition, the semiconductor light emitting device according to the present disclosure Device In one aspect, the distance between the light-transmitting window and the light-emitting surface of the semiconductor light-emitting element may be greater than zero and less than the thickness of the light-transmitting window.

[0020] In addition, the semiconductor light emitting device according to the present disclosure Device In one aspect, the thickness of the side wall other than the light-transmitting window among the four side walls may be greater than the thickness of the light-transmitting window.

[0021] In addition, the semiconductor light emitting device according to the present disclosure Device In one aspect, the cap unit has a rectangular top plate and four side walls connected to the four peripheral sides of the top plate, and the top plate is a translucent window having an inorganic translucent plate and an anti-reflection film formed on the inorganic translucent plate, and the emitted light from the semiconductor light-emitting element may pass through the translucent window.

[0022] In addition, the semiconductor light emitting device according to the present disclosure Device In one aspect, the semiconductor light emitting device may include a reflective optical element, and light emitted from the semiconductor light emitting element may be reflected by the reflective optical element and propagate in a direction perpendicular to an upper surface of the wiring substrate.

[0023] In addition, the semiconductor light emitting device according to the present disclosure Device In one aspect, the semiconductor device may further include a functional element disposed on the wiring substrate.

[0024] In addition, the semiconductor light emitting device according to the present disclosure Device In one aspect, the functional element may be covered by the cap unit.

[0025] In addition, the semiconductor light emitting device according to the present disclosure Device In one aspect, the functional element may be a temperature sensing element.

[0026] In addition, the semiconductor light emitting device according to the present disclosure Device In one aspect of the present invention, the temperature detection element may be disposed at a position that does not intersect with the optical axis of the semiconductor light emitting element.

[0027] In addition, the semiconductor light emitting device according to the present disclosure Device In one aspect, the temperature detection element may further include a shielding member disposed between the temperature detection element and the semiconductor light emitting element.

[0028] In addition, the semiconductor light emitting device according to the present disclosure Device In one aspect, the first substrate may have an obliquely cut surface at an end thereof.

[0029] In addition, in order to solve the above problem, one aspect of the light source device according to the present disclosure comprises the semiconductor light emitting device, a heat sink on which the semiconductor light emitting device is placed, and a fixing screw for fixing the semiconductor light emitting device to the heat sink, wherein a through hole is formed in the wiring board, and the fixing screw passes through the through hole and is fixed to the heat sink.

[0030] Furthermore, one aspect of the light source device according to the present disclosure may include a cable having a terminal and a terminal fixing screw, the wiring board having an extraction electrode electrically connected to the first metal layer, an electrode through hole formed in the center of the extraction electrode, the terminal fixing screw passing through the electrode through hole, the terminal being disposed between the terminal fixing screw and the extraction electrode, and the extraction electrode and the terminal being electrically connected. [Effects of the Invention]

[0031] According to the present disclosure, it is possible to provide a semiconductor light emitting device or the like that has a simplified configuration and is capable of realizing a semiconductor light emitting element with high optical output and improved reliability. [Brief explanation of the drawings]

[0032] [Figure 1A] FIG. 1A is a schematic perspective view showing the overall configuration of a semiconductor light emitting device according to the first embodiment. [Figure 1B]FIG. 1B is a schematic top view showing the overall configuration of the semiconductor light emitting device according to the first embodiment. [Figure 2] FIG. 2 is a schematic perspective view showing the internal configuration of the cap unit of the semiconductor light emitting device according to the first embodiment. [Figure 3A] FIG. 3A is a schematic exploded perspective view illustrating the overall configuration of the semiconductor light emitting device according to the first embodiment. [Figure 3B] FIG. 3B is an equivalent circuit illustrating the circuit configuration of the semiconductor light emitting device according to the first embodiment. [Figure 4] FIG. 4 is a schematic cross-sectional view illustrating the overall configuration of the semiconductor light emitting device according to the first embodiment. [Figure 5] FIG. 5 is a schematic top view showing the positional relationship between the semiconductor light emitting element, each metal layer, each spacer layer, and the bonding surface of the cap unit of the semiconductor light emitting device according to the first embodiment. [Figure 6A] FIG. 6A is a schematic cross-sectional view showing a bonding state between a wiring board and a cap unit according to a comparative example. [Figure 6B] FIG. 6B is a schematic cross-sectional view showing a bonded state between the wiring board and the cap unit according to the first embodiment. [Figure 7] FIG. 7 is a schematic diagram illustrating the dimensions of the first metal layer according to the first embodiment. [Figure 8] FIG. 8 is a graph showing the relationship between the applied current and the operating voltage and light output of the semiconductor light emitting device according to the first embodiment. [Figure 9] FIG. 9 is a table showing an example of a metal layer design. [Figure 10A] FIG. 10A is a schematic cross-sectional view illustrating a first step of the method for manufacturing the wiring board according to the first embodiment. [Figure 10B] FIG. 10B is a schematic cross-sectional view illustrating a second step of the method for manufacturing the wiring board according to the first embodiment. [Figure 10C] FIG. 10C is a schematic cross-sectional view illustrating a third step of the method for manufacturing the wiring board according to the first embodiment. [Figure 10D]FIG. 10D is a schematic cross-sectional view illustrating a fourth step of the method for manufacturing the wiring board according to the first embodiment. [Figure 10E] FIG. 10E is a schematic cross-sectional view illustrating a fifth step of the method for manufacturing the wiring board according to the first embodiment. [Figure 10F] FIG. 10F is a schematic cross-sectional view illustrating a sixth step of the method for manufacturing the wiring board according to the first embodiment. [Figure 10G] FIG. 10G is a schematic cross-sectional view illustrating a seventh step of the method for manufacturing the wiring board according to the first embodiment. [Figure 11] FIG. 11 is a schematic perspective view illustrating a method for manufacturing the cap unit according to the first embodiment. [Figure 12A] FIG. 12A is a schematic cross-sectional view illustrating a method for attaching the cap unit to the wiring board according to the first embodiment. [Figure 12B] FIG. 12B is a schematic cross-sectional view of a light source device using the semiconductor light emitting device according to the first embodiment. [Figure 13A] FIG. 13A is a schematic top view showing the configuration of each spacer layer of a semiconductor light emitting device according to Modification 1 of Embodiment 1. FIG. [Figure 13B] FIG. 13B is a schematic top view showing the configuration of each spacer layer of the semiconductor light emitting device according to the second modification of the first embodiment. [Figure 14A] FIG. 14A is a schematic top view showing the positional relationship between a semiconductor light emitting element, a temperature detecting element, and a shielding member in a semiconductor light emitting device according to Modification 3 of Embodiment 1. FIG. [Figure 14B] FIG. 14B is a schematic cross-sectional view showing the positional relationship between the semiconductor light emitting element, the temperature detecting element, and the shielding member of the semiconductor light emitting device according to the third modification of the first embodiment. [Figure 15] FIG. 15 is a schematic perspective view showing the overall configuration of a semiconductor light emitting device according to the second embodiment. [Figure 16] FIG. 16 is a schematic perspective view showing the overall configuration of a semiconductor light emitting device according to the second embodiment. [Figure 17]FIG. 17 is a schematic cross-sectional view showing the overall configuration of a semiconductor light emitting device according to the second embodiment. [Figure 18] FIG. 18 is a top view showing the arrangement of temperature detection elements according to the second embodiment. [Figure 19A] FIG. 19A is a first schematic cross-sectional view illustrating a method for joining a cap unit of a semiconductor light emitting device according to Embodiment 2 to a wiring substrate. [Figure 19B] FIG. 19B is a second schematic cross-sectional view illustrating a method for joining the cap unit of the semiconductor light emitting device according to the second embodiment to the wiring substrate. [Figure 19C] FIG. 19C is a third schematic cross-sectional view illustrating a method for joining the cap unit of the semiconductor light emitting device according to the second embodiment to the wiring substrate. [Figure 20] FIG. 20 is a schematic perspective view showing the configuration of a light source device according to the second embodiment. [Figure 21] FIG. 21 is a schematic exploded perspective view showing the configuration of the light source device according to the second embodiment. [Figure 22A] FIG. 22A is a schematic cross-sectional view showing a state in which a terminal fixing screw according to Modification 1 of Embodiment 2 is fixed to a heat sink. [Figure 22B] FIG. 22B is an exploded cross-sectional view showing a method for fixing the terminal fixing screw to the heat sink according to the first modification of the second embodiment. [Figure 23] FIG. 23 is a schematic perspective view showing the overall configuration of a semiconductor light emitting device according to the third embodiment. [Figure 24] FIG. 24 is a schematic exploded perspective view showing the overall configuration of a semiconductor light emitting device according to the third embodiment. [Figure 25] FIG. 25 is a schematic cross-sectional view showing the overall configuration of a semiconductor light emitting device according to the third embodiment. [Figure 26] FIG. 26 is a schematic top view showing the overall configuration of a semiconductor light emitting device according to a modification of the third embodiment. [Figure 27] FIG. 27 is a schematic top view showing the overall configuration of a semiconductor light emitting device according to the fourth embodiment. [Figure 28] FIG. 28 is a schematic perspective view showing the configuration of a semiconductor light emitting device according to a reference example. DETAILED DESCRIPTION OF THE INVENTION

[0033] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that each of the embodiments described below represents a specific example of the present disclosure. Therefore, the numerical values, shapes, materials, components, and the arrangement and connection of the components shown in the following embodiments are merely examples and are not intended to limit the present disclosure.

[0034] Furthermore, each figure is a schematic diagram and is not necessarily an exact representation. Therefore, the scales and the like do not necessarily match in each figure. In each figure, the same reference numerals are used to denote substantially the same components, and redundant explanations will be omitted or simplified.

[0035] In addition, in this specification, the terms "upper" and "lower" refer to absolute spatial recognition. Lead Directly above and lead Directly below How to It does not refer to a specific location, but is used as a term that defines a relative positional relationship based on the stacking order in the stacking configuration. Furthermore, the terms "above" and "below" are applicable not only to the case where two components are arranged with a gap between them and another component exists between them, but also to the case where two components are arranged in contact with each other.

[0036] (Embodiment 1) A semiconductor light emitting device according to an embodiment will be described.

[0037] [1-1. Overall structure] First, the overall configuration of a semiconductor light-emitting device according to the present embodiment will be described with reference to FIGS. 1A to 4. FIGS. 1A and 1B are a schematic perspective view and a top view, respectively, showing the overall configuration of a semiconductor light-emitting device 10 according to the present embodiment. FIG. 2 is a schematic perspective view showing the internal configuration of a cap unit 50 of the semiconductor light-emitting device 10 according to the present embodiment. FIG. 2 shows the semiconductor light-emitting device 10 with a portion of the cap unit 50 removed. FIG. 3A is a schematic exploded perspective view illustrating the overall configuration of the semiconductor light-emitting device 10 according to the present embodiment. FIG. 3B is an equivalent circuit illustrating the circuit configuration of the semiconductor light-emitting device 10 according to the present embodiment. FIG. 4 is a schematic cross-sectional view illustrating the overall configuration of the semiconductor light-emitting device 10 according to the present embodiment. FIG. 4 shows the semiconductor light-emitting device 10 in a cross section taken along line IV-IV shown in FIG. 1B.

[0038] Semiconductor light emitting device 10 according to this embodiment is a device that emits light, and as shown in Fig. 3A, includes wiring substrate 20, semiconductor light emitting element 41, and cap unit 50. In this embodiment, semiconductor light emitting device 10 further includes submount 45, temperature detection element 60, connector 70, and bonding members 26, 42, 55, and 62, as shown in Fig. 4. Each component of semiconductor light emitting device 10 will be described below.

[0039] [1-1-1. Wiring board] The wiring substrate 20 is a plate-like member that serves as a base for the semiconductor light-emitting device 10 and has wiring provided thereon. An upper surface 20a of the wiring substrate 20 is a component mounting surface, and a lower surface opposite the upper surface 20a (i.e., the surface behind the upper surface 20a) is a heat dissipation surface 20b. As shown in FIG. 4, the wiring substrate 20 includes a metal substrate 28, a first insulating layer 21, a second insulating layer 22, spacer layers 30a and 30b, a third metal layer 33, a fourth metal layer 34, and protective films 25 and 35. As shown in FIGS. 2 and 3A, the wiring substrate 20 further includes a first metal layer 31, a second metal layer 32, a first pad electrode 31p, and a second pad electrode 32p. 1A, 1B, 2, and 3A, the first metal layer 31, the second metal layer 32, the third metal layer 33, the fourth metal layer 34, and each spacer layer are covered by the second insulating layer 22 and therefore do not appear on the surface. However, the portions of the second insulating layer 22 on each of the above layers protrude upward, and therefore the positions of the edges of each of the above layers are shown as the positions of steps in the second insulating layer 22. Furthermore, because each of the above layers is covered by the second insulating layer 22, the reference symbols indicating these metal layers are indicated by dashed lines. The same applies to each metal layer and each spacer layer shown in the top view and perspective view described below.

[0040] In this embodiment, wiring substrate 20 is formed with through holes 28a and 28b and positioning holes 29a and 29b. Through holes 28a and 28b are holes for inserting fixing members such as screws when closely fixing wiring substrate 20 to a heat sink or the like. Through holes 28a and 28b are respectively disposed on one side and the other side of an area of ​​wiring substrate 20 where semiconductor light emitting element 41 is disposed. Note that, hereinafter, the upward and downward directions in FIG. 1B are referred to as "one side" and "the other side," respectively. In other words, semiconductor light emitting element 41 is disposed between through holes 28a and 28b.

[0041] Positioning holes 29a and 29b are holes used to position wiring board 20 relative to a heat sink or the like when fixing wiring board 20 to the heat sink or the like. For example, positioning pins provided at positions where positioning holes 29a and 29b on the heat sink or the like should be located are fitted into positioning holes 29a and 29b. This allows wiring board 20 to be positioned at a predetermined position on the heat sink or the like. In this embodiment, positioning hole 29a is a first positioning hole and is a hole having a circular shape when viewed from above on wiring board 20. Positioning hole 29b is a second positioning hole and is a hole having an elongated (i.e., oval) shape when viewed from above on wiring board 20.

[0042] The metal substrate 28 is an example of a first substrate included in the wiring board 20. The metal substrate 28 is made of a flat metal plate such as oxygen-free copper or a copper alloy. Here, a flat plate refers to a plate whose surface, other than the peripheral portion, has a depth or height greater than its surface roughness and no patterned irregularities. By flattening the upper surface of the metal substrate 28, a flat first insulating layer 21 can be formed on the metal substrate 28. This makes it easier to form a thick metal layer on the first insulating layer 21. The metal substrate 28 is a flat plate made of oxygen-free copper, for example, with a thickness of approximately 0.5 mm to 3 mm. The shape of the metal substrate 28 (i.e., the shape when viewed from above) is, for example, rectangular, and the length of one side of the metal substrate 28 is, for example, approximately 5 mm to 30 mm. In this embodiment, an obliquely cut surface 28c, which is an inclined surface inclined with respect to the main surface of the metal substrate 28, is formed at the edge portion of the metal substrate 28. A first insulating layer 21 is formed on the upper surface of the metal substrate 28, and no insulating layer is formed on the lower surface (i.e., the surface behind the upper surface) of the metal substrate 28. This allows the entire area of ​​the lower surface of the metal substrate 28 to be used as the heat dissipation surface 20b of the wiring board 20, allowing heat to be dissipated over a large area. This makes it possible to use a semiconductor light emitting element 41 that generates a large amount of heat and has a high optical output.

[0043] 4, the first insulating layer 21 is an insulating layer disposed on the upper surface of the metal substrate 28. The first insulating layer 21 is made of an insulating material such as epoxy glass or ceramic, with a thickness of, for example, about 0.05 mm or more and 0.3 mm or less.

[0044] 2, 3A, and 4, an opening 21a is formed in the first insulating layer 21. In this embodiment, a portion of the first insulating layer 21 is removed to form a rectangular opening 21a. The opening 21a is formed at a position closer to the end than the center of the metal substrate 28 when viewed from above. As shown in FIG. 4, a protective film 25 made of Ni, Au, or the like is formed in a region of the metal substrate 28 corresponding to the opening 21a, and a mounting surface for mounting a semiconductor light emitting element 41 is formed. In this embodiment, the semiconductor light emitting element 41 is disposed in the opening 21a via a submount 45.

[0045] The first metal layer 31, the second metal layer 32, the third metal layer 33, and the fourth metal layer 34 are metal layers spaced apart from one another on the first substrate, and in this embodiment, are disposed on the first insulating layer 21. The first metal layer 31 and the second metal layer 32 are wiring for supplying power to the semiconductor light emitting element 41. The third metal layer 33 and the fourth metal layer 34 are wiring connected to the temperature detection element 60. Each metal layer forms a protrusion on the first insulating layer 21. The first metal layer 31, the second metal layer 32, the third metal layer 33, and the fourth metal layer 34 are metal layers made of copper and having a thickness of, for example, approximately 0.02 mm or more and 0.15 mm or less.

[0046] The spacer layers 30a and 30b are layers disposed at positions different from the first metal layer 31 and the second metal layer 32 on the first substrate, and in this embodiment, are disposed on the first insulating layer 21. As shown in FIG. 4, the spacer layers 30a and 30b are disposed between the bonding surface 50b of the cap unit 50 with the wiring substrate 20 and the first insulating layer 21. Like each metal layer, the spacer layers 30a and 30b form convex portions on the first insulating layer 21. The material constituting the spacer layers 30a and 30b is not particularly limited. In this embodiment, the spacer layers 30a and 30b are made of a metal material. The spacer layers 30a and 30b are, for example, metal layers made of copper with a thickness of approximately 0.02 mm or more and 0.15 mm or less, similar to the first metal layer 31.

[0047] The second insulating layer 22 is an insulating layer disposed on the first insulating layer 21. The second insulating layer 22 covers at least a portion of the first metal layer 31, the second metal layer 32, the third metal layer 33, the fourth metal layer 34, and the spacer layers 30a and 30b, and also functions to protect these layers. The second insulating layer 22 is an insulating layer made of a resin such as polyimide or epoxy, for example, with a thickness of approximately 0.05 mm or more and 0.2 mm or less.

[0048] The protective film 25 is a metal film disposed on the wiring substrate 20 at a position where the submount 45 and the like are bonded. In this embodiment, the protective film 25 is disposed in a region corresponding to the opening 21a of the first insulating layer 21 of the metal substrate 28. The protective film 35 is a metal film disposed on the surface of a metal layer, such as the first metal layer 31, that is exposed from the second insulating layer 22. The protective film 35 is disposed on a portion of the upper surfaces of the first metal layer 31, the second metal layer 32, the third metal layer 33, and the fourth metal layer 34. The protective films 25 and 35 also serve as anti-corrosion films that protect the exposed surfaces of the metal substrate 28 and the first metal layer 31 from oxidation and the like. The protective films 25 and 35 are made of, for example, Ni, Au, or the like.

[0049] The first pad electrode 31p and the second pad electrode 32p are pad-shaped electrodes disposed on portions of the first metal layer 31 and the second metal layer 32 adjacent to the semiconductor light emitting element 41, respectively. As shown in Figures 2 and 3A, metal wires W2 and W3 are bonded to the first pad electrode 31p and the second pad electrode 32p, respectively. In this embodiment, the first pad electrode 31p and the second pad electrode 32p are also part of the protective film 35 and are made of, for example, Ni, Au, or the like.

[0050] [1-1-2. Semiconductor light-emitting element] The semiconductor light emitting element 41 is a light emitting element disposed on the upper surface 20a of the wiring substrate 20. The semiconductor light emitting element 41 is disposed in the opening 21a of the first insulating layer 21. The semiconductor light emitting element 41 is a light emitting element made of a compound semiconductor such as a gallium nitride-based or gallium arsenide-based compound semiconductor. In this embodiment, the semiconductor light emitting element 41 is a semiconductor laser element having an optical waveguide extending in a direction parallel to the main surface of the metal substrate 28.

[0051] As shown in FIG. 4, the semiconductor light-emitting element 41 is mounted on a submount 45. The semiconductor light-emitting element 41 has a substrate and a semiconductor laminate stacked on the substrate. An optical waveguide is formed in the semiconductor laminate. In this embodiment, the semiconductor laminate of the semiconductor light-emitting element 41 is disposed facing the submount 45. That is, the semiconductor light-emitting element 41 is junction-down mounted on the submount 45. Electrodes (not shown) are formed on the upper surface (i.e., the upper surface of the semiconductor light-emitting element 41 in FIG. 4) and the lower surface (i.e., the lower surface of the semiconductor light-emitting element 41 in FIG. 4). The lower surface of the semiconductor light-emitting element 41 faces the upper surface of the submount 45. As shown in FIG. 5, the electrode formed on the lower surface of the semiconductor light-emitting element 41 facing the submount 45 is electrically connected to a first electrode 47 formed on the upper surface of the submount 45. More specifically, the electrode formed on the lower surface of the semiconductor light-emitting element 41 is electrically connected to the first electrode 47 formed on the upper surface of the submount 45 via a bonding member 42 (see FIG. 4) made of AuSn solder or the like. The electrode formed on the upper surface of the semiconductor light emitting element 41 is electrically connected to a second electrode 48 formed on the upper surface of the submount 45 via a metal wire W1. The first electrode 47 and the second electrode 48 formed on the upper surface of the submount 45 are electrically connected to the first pad electrode 31p and the second pad electrode 32p via metal wires W2 and W3, respectively. With this configuration, a current can be supplied to the semiconductor light emitting element 41 using the first metal layer 31 and the second metal layer 32 connected to the first pad electrode 31p and the second pad electrode 32p, respectively.

[0052] As shown in FIG. 4, the semiconductor light-emitting element 41 has a light-emitting point 41e that emits emitted light L1. In this embodiment, the emitted light L1 is laser light. If the semiconductor light-emitting element 41 includes a gallium nitride-based compound semiconductor, the emitted light L1 is laser light having a peak wavelength in the wavelength range of 270 nm to 600 nm, for example. If the semiconductor light-emitting element 41 includes a gallium indium phosphide-based compound semiconductor or a gallium arsenide-based compound semiconductor, the emitted light L1 is laser light having a peak wavelength in the wavelength range of 600 nm to 10.4 μm, for example. The light-emitting point 41e is an end portion of the optical waveguide of the semiconductor light-emitting element 41 located on the left side in FIG. 4. The semiconductor light-emitting element 41 is disposed so that the emission surface, which is the end face where the light-emitting point 41e is located, protrudes from the end face of the submount 45 (the left end face of the submount 45 shown in FIG. 4). This prevents the emitted light L1 emitted from the light-emitting point 41e from being blocked by the submount 45.

[0053] The semiconductor light emitting element 41 has a rectangular parallelepiped shape with a width of about 0.2 mm to 2 mm, a length of about 1 mm to 9 mm, and a thickness of about 0.08 mm to 0.2 mm.

[0054] [1-1-3. Submount] The submount 45 is a component disposed between the wiring substrate 20 and the semiconductor light-emitting element 41. The submount 45 is mounted on the upper surface 20a of the wiring substrate 20. More specifically, as shown in FIG. 4, the submount 45 is disposed inside the opening 21a of the first insulating layer 21 and mounted to the metal substrate 28 via the bonding member 26 and the protective film 25. The bonding member 26 is made of, for example, AuSn solder. The semiconductor light-emitting element 41 is mounted on the upper surface of the submount 45. In this embodiment, the submount 45 includes an insulating block, which is a rectangular parallelepiped block made of an insulating material; a first electrode 47 and a second electrode 48, which are metal films disposed on the upper surface of the insulating block; and a metal film (not shown) disposed on the lower surface of the insulating block. The insulating block is made of an insulating material with high thermal conductivity, such as AlN, SiC, or diamond. The insulating block has a rectangular parallelepiped shape with a width of approximately 1 mm to 5 mm, a length of approximately 2 mm to 10 mm, and a thickness of approximately 0.2 mm to 4 mm. The first electrode 47 and the second electrode 48 are spaced apart from each other and electrically insulated from each other. The first electrode 47 and the second electrode 48 are also electrically insulated from a metal film disposed on the lower surface of the insulating block. The first electrode 47, the second electrode 48, and the metal film disposed on the lower surface of the insulating block are metal films made of Ni, Cu, Ti, Pt, Au, or the like.

[0055] As described above, in the semiconductor light-emitting device 10 according to this embodiment, the semiconductor light-emitting element 41 is mounted on the metal substrate 28 via the submount 45. With this configuration, heat generated in the semiconductor light-emitting element 41 can be efficiently dissipated to the metal substrate 28 via the submount 45, as shown by the arrows in FIG. 4 . The lower surface of the metal substrate 28 is in close contact with, for example, a heat sink (not shown). This allows the heat generated in the semiconductor light-emitting element 41 to be efficiently conducted from the metal substrate 28 to the heat sink. Furthermore, because the metal substrate 28 according to this embodiment is a flat plate, it is easy to manufacture and costs can be reduced. Therefore, a semiconductor light-emitting device 10 having a simplified configuration and that can be manufactured at low cost can be realized.

[0056] [1-1-4. Cap Unit] As shown in FIGS. 1A, 1B, 2, and 4, the cap unit 50 is disposed on the upper surface 20a of the wiring substrate 20 and is a cover member that covers the semiconductor light-emitting element 41. As shown in FIG. 4, the cap unit 50 has a bonding surface 50b facing the wiring substrate 20. The bonding surface 50b has an annular shape, and the bonding surface 50b and the upper surface 20a of the wiring substrate 20 are bonded with a bonding member 55 made of an epoxy adhesive, a silicone adhesive, an AuSn solder, or the like. This seals the gap between the cap unit 50 and the wiring substrate 20. In this embodiment, as shown in FIG. 2, the cap unit 50 covers the opening 21a of the first insulating layer 21, the semiconductor light-emitting element 41 and the submount 45 disposed in the opening 21a, the first pad electrode 31p and the second pad electrode 32p, and portions of the first metal layer 31 and the second metal layer 32. The cap unit 50 has a rectangular top plate 52d (see FIG. 4) and four side walls 51, 52a, 52b, and 52c (see FIG. 2) connected to the four sides of the periphery of the top plate 52d. In the present embodiment, one side wall 51 of the four side walls 51, 52a, 52b, and 52c is a light-transmitting window, and as shown in FIG. 4, the side wall 51 has an inorganic light-transmitting plate 51a and anti-reflection films 51b and 51c disposed on the inorganic light-transmitting plate 51a. In the present embodiment, the side wall 51 has anti-reflection films 51b and 51c disposed on each main surface of the inorganic light-transmitting plate 51a. The anti-reflection film 51b is disposed on the main surface of the inorganic light-transmitting plate 51a facing the semiconductor light-emitting element 41, and the anti-reflection film 51c is disposed on the main surface behind the main surface. The three side walls 52a, 52b, and 52c and the top plate 52d are integrally formed to constitute the holder 52. The side walls 52a, 52b, and 52c are disposed in a position facing the light emitting point 41e of the semiconductor light emitting element 41. As a result, the emitted light L1 from the semiconductor light emitting element 41 passes through the side walls 51, which are light-transmitting windows.

[0057] The holder 52 is made of, for example, glass and is manufactured by, for example, forming recesses in a rectangular parallelepiped glass block using a sandblaster or the like and dividing the block.

[0058] The side wall 51, which is a light-transmitting window, and the holder 52 are joined by optical contact or laser welding to form a box-shaped cap unit.

[0059] The cap unit 50 having the above-described configuration allows the emitted light L1 from the semiconductor light emitting element to be easily extracted to the outside from the side wall 51 of the cap unit 50.

[0060] The thickness Dg of the side wall 51, which is a light-transmitting window shown in FIG. 4, is approximately 0.01 mm or more and 0.2 mm or less. The distance Dgap between the side wall 51, which is a light-transmitting window, and the light-emitting surface of the semiconductor light-emitting element 41 (i.e., the end face including the light-emitting point 41e) is greater than zero and less than the thickness Dg of the side wall 51. This makes it possible to reduce the distance (Dg+Dgap) from the light-emitting point 41e of the semiconductor light-emitting element 41 to the outside of the cap unit 50. Therefore, the beam cross-sectional area S of the emitted light L1 on the outer surface of the cap unit 50 is L1 For example, when the output light L1 is incident on an optical element such as a lens disposed outside the cap unit 50, the beam cross-sectional area S L1 By reducing the size of the optical element, the size of the optical element can be reduced, and the output light L1 can be easily coupled to the optical element.

[0061] The thickness of the side walls 52a, 52b, and 52c is greater than the thickness of the side wall 51, which is a light-transmitting window. This makes it possible to increase the structural strength of the holder and the cap unit 50 while reducing the distance (Dg+Dgap) from the light-emitting point 41e of the semiconductor light-emitting element 41 to the outside of the cap unit 50.

[0062] [1-1-5. Functional elements] The semiconductor light-emitting device 10 may include functional elements other than the semiconductor light-emitting element 41. In this embodiment, the semiconductor light-emitting device 10 includes a temperature detection element 60 as an example of a functional element. The temperature detection element 60, which is an example of a functional element, will be described below. The temperature detection element 60 is a temperature sensor disposed on the wiring substrate 20. As shown in FIG. 4 , the temperature detection element 60 is electrically connected to the third metal layer 33 and the fourth metal layer 34 via a bonding member 62 and a protective film 35. The protective film 35 also serves as pad electrodes disposed on the third metal layer 33 and the fourth metal layer 34. The temperature detection element 60 is mounted on the surface of the wiring substrate 20 by the bonding member 62, such as SnAgCu solder paste. The temperature detection element 60 can detect the temperature of the wiring substrate 20. By detecting the temperature of the wiring substrate 20, the temperature of the semiconductor light-emitting element 41 mounted on the wiring substrate 20 via the submount 45 can be estimated. Therefore, the temperature of the semiconductor light-emitting element 41 can be estimated using the temperature detection element 60 and used to control the semiconductor light-emitting element 41. For example, when the temperature detection element 60 detects that the temperature of the semiconductor light emitting element 41 is higher than a predetermined threshold, the current supplied to the semiconductor light emitting element 41 can be reduced or stopped. The temperature detection element 60 can be, for example, a thermistor. In this case, a predetermined voltage is applied to the temperature detection element 60, and the resistance value of the temperature detection element 60 is detected by detecting the current flowing through the temperature detection element 60. The temperature of the wiring substrate 20 can be detected from the correlation between this resistance value and temperature. A voltage is applied to the temperature detection element 60 via the third metal layer 33 and the fourth metal layer 34. In this embodiment, the temperature detection element 60 is disposed outside the cap unit 50. This allows the cap unit 50 to be miniaturized. Therefore, the gap between the cap unit 50 and the wiring substrate 20 can be easily sealed.

[0063] [1-1-6. Connector] The connector 70 is a connecting component having terminals connected to the first metal layer 31 and the second metal layer 32, respectively. The connector 70 connects the wiring board 20 to an external electric circuit (not shown). In this embodiment, the connector 70 is a receptacle further having terminals connected to the third metal layer 33 and the fourth metal layer 34, respectively, as shown in FIG. 3B and other figures. Pad electrodes 31q, 32q, 33q, and 34q made of a protective film 35 are formed on the ends of the first metal layer 31, the second metal layer 32, the third metal layer 33, and the fourth metal layer 34 farther from the location where the semiconductor light emitting element 41 is disposed, and are connected to the connector 70. The connector 70 is mounted on the surface of the wiring board 20 using a bonding material (not shown) such as SnAgCu solder paste, and is connected to the pad electrodes 31q, 32q, 33q, and 34q.

[0064] [1-2. Actions and Effects] Next, the operation and effect of the semiconductor light-emitting device 10 according to the present embodiment will be described with reference to the above-mentioned FIGS. 4 and 5 to 6B. FIG. 5 is a schematic top view showing the positional relationship between the semiconductor light-emitting element 41, each metal layer, and each spacer layer of the semiconductor light-emitting device 10 according to the present embodiment and the bonding surface 50b of the cap unit 50. FIG. 5 shows the semiconductor light-emitting element 41 and its surrounding structure of the semiconductor light-emitting device 10 with the cap unit 50 and the second insulating layer 22 removed. The edge of the bonding surface 50b of the cap unit 50 is indicated by a dashed line in FIG. 5. FIGS. 6A and 6B are schematic cross-sectional views showing the bonding state between the wiring boards of the comparative example and the present embodiment and the cap unit 50, respectively. FIG. 6B shows the wiring board 20 and other components in a cross section taken along line VI-VI in FIG. 5. FIG. 6A shows a cross-section of the wiring board and cap unit 50 of the comparative example at the same position as FIG. 6B. Each cross-sectional view (a) in FIG. 6A and FIG. 6B shows a cross-sectional view before bonding the cap unit 50 and each wiring board, and each cross-sectional view (b) shows a cross-sectional view after bonding.

[0065] 5, the first pad electrode 31p, the second pad electrode 32p, the first metal layer 31, and the second metal layer 32 extend in the optical axis direction of the semiconductor light emitting element 41 (i.e., the direction in which the optical waveguide extends, or in other words, the resonance direction). The first pad electrode 31p and the first metal layer 31 are arranged on one side of the semiconductor light emitting element 41 (and the opening 21a). The second pad electrode 32p and the second metal layer 32 are arranged on the other side of the semiconductor light emitting element 41 (the opposite side).

[0066] The first metal layer 31 and the second metal layer 32 extend from inside the cap unit 50 toward the rear of the semiconductor light emitting element 41 (i.e., in the opposite direction to the propagation direction of the emitted light L1) to the outside of the cap unit 50. Therefore, a bonding surface 50b of the cap unit 50 that is bonded to the wiring substrate 20 intersects with the first metal layer 31 and the second metal layer 32 in a top view of the wiring substrate 20. Note that a portion of the first metal layer 31 where the first pad electrode 31p and the pad electrode 31q are not provided is covered with the second insulating layer 22. A portion of the second metal layer 32 where the second pad electrode 32p and the pad electrode 32q are not provided is covered with the second insulating layer 22.

[0067] 4 and 5, the spacer layers 30a and 30b are disposed between the bonding surface 50b and the first insulating layer 21. The spacer layer 30a is disposed on the side of the rear end face 41R opposite the emission surface 41F including the light-emitting point 41e of the semiconductor light-emitting element 41, extending from the other side of the first metal layer 31 (the side closer to the second metal layer 32) to the one side of the second metal layer 32 (the side closer to the first metal layer 31). The spacer layer 30b is composed of five portions. The first portion of the spacer layer 30b is disposed on the side of the rear end face 41R, extending laterally (in the plane of the main surface of the wiring substrate 20, in a direction perpendicular to the optical axis direction) from the one side of the first metal layer 31 (the side farther from the second metal layer 32). The second portion of the spacer layer 30b is connected to the first portion and is disposed on a side of one of the first pad electrode 31p and the first metal layer 31 (the side farther from the second metal layer 32) so as to extend in the optical axis direction. The third portion of the spacer layer 30b is connected to the second portion and is disposed on a side of the emission surface 41F so as to extend in the horizontal direction. The fourth portion of the spacer layer 30b is connected to the third portion and is disposed on a side of the other of the second pad electrode 32p and the second metal layer 32 (the side farther from the first metal layer 31) so as to extend in the optical axis direction. The fifth portion of the spacer layer 30b is connected to the fourth portion and is disposed on a side of the rear end face 41R so as to extend in the horizontal direction from a side of the other of the second metal layer 32 (the side farther from the first metal layer 31).

[0068] The effect of this configuration will be described with reference to Figures 6A and 6B. The wiring board of the comparative example shown in Figure 6A is a wiring board in which spacer layers 30a and 30b have been removed from wiring board 20 according to the present embodiment.

[0069] The first metal layer 31 and the second metal layer 32 in the comparative example and the present embodiment have large cross-sectional areas so as to supply a large current to the semiconductor light-emitting element 41. Therefore, the thicknesses of the first metal layer 31 and the second metal layer 32 are approximately 0.02 mm or more and 0.15 mm or less. The second insulating layer 22 on each metal layer is formed by applying a liquid insulating material onto the first metal layer 31 and the second metal layer 32 and curing it, and has a thickness of approximately 0.02 mm or more and 0.1 mm or less. Therefore, the top surface of the second insulating layer 22 has an uneven shape that conforms to the top surfaces of the first insulating layer 21 and each metal layer, as shown in the cross-sectional view (a) of FIG. 6A . That is, on the top surface of the wiring substrate, a recess with a depth approximately equal to the thickness of the first metal layer 31 and the second metal layer 32 is formed in the region between the first metal layer 31 and the second metal layer 32.

[0070] When using a comparative wiring board without spacers, as shown in FIG. 6A, a large gap is formed between the recessed portion on the upper surface of the wiring board and the cap unit 50. To fill the gap between the wiring board and the cap unit with adhesive, a method is considered in which adhesive is applied to the wiring board to a predetermined thickness and then crushed with the cap unit to fill the gap. In this case, a large amount of adhesive is used to form a adhesive layer along the bonding surface 50b in advance, which is sufficiently thicker than the height of the irregularities on the wiring board surface. Therefore, when the adhesive layer is crushed, unnecessary adhesive may protrude from between the bonding surface between the wiring board and the cap unit and spread across the wiring board toward the opening 21a and the connector 70. This may alter the functionality of the functional components arranged inside and outside the cap unit. In particular, if the adhesive spreads toward the through holes 28a, 28b and the positioning holes 29a, 29b, the hole shape may change. Furthermore, if the adhesive spreads from the bonding surface facing the light-emitting point 41e toward the semiconductor light-emitting element 41, the characteristics of the emitted light L1 may be significantly altered. If the distance between the bonding surface and the functional component is increased to reduce the effect of the protruding bonding material, it becomes difficult to miniaturize the semiconductor light-emitting device. Furthermore, when attempting to bond the wiring substrate 20 and the cap unit 50 with a small amount of bonding material, a gap 55v where no bonding material 55 is present is formed between the upper surface of the wiring substrate and the bonding surface 50b of the cap unit 50, as shown in the cross-sectional view (b) of FIG. 6A. Therefore, when the wiring substrate of the comparative example is used, it is not possible to seal the gap between the upper surface of the wiring substrate and the bonding surface 50b of the cap unit 50.

[0071] On the other hand, in the wiring board 20 according to this embodiment, as shown in the cross-sectional view (a) of FIG. 6B , spacer layers 30a and 30b are disposed between the bonding surface 50b and the first insulating layer 21, at positions different from the first metal layer 31 and the second metal layer 32. Because the spacer layers 30a and 30b are disposed between the first metal layer 31 and the second metal layer 32, the dimension and depth of the recess formed between the first metal layer 31 and the second metal layer 32 on the upper surface 20a of the wiring board 20 in a direction parallel to the main surface of the metal substrate 28 can be reduced. Therefore, as shown in the cross-sectional view (b) of FIG. 6B , the recess on the upper surface 20a of the wiring board 20 can be filled with a small amount of bonding material 55. Therefore, the gap between the upper surface 20a of the wiring board 20 and the bonding surface 50b of the cap unit 50 can be sealed with a small amount of bonding material. This prevents foreign matter from entering the cap unit 50 and prevents the bonding material from affecting functional components around the bonding surface. That is, it is possible to realize a highly reliable semiconductor light emitting device 10. Furthermore, since the first metal layer 31 and the second metal layer 32 have large cross-sectional areas, a large current can be applied to the semiconductor light emitting device 10, thereby achieving high light output.

[0072] 5, the spacer layers 30a and 30b are disposed along a portion of the bonding surface 50b between the portion facing the first metal layer 31 and the portion facing the second metal layer 32. This increases the area where either the metal layers or the spacer layers are disposed between the bonding surface 50b and the wiring substrate 20. This reduces the formation of a gap between the bonding surface 50b and the wiring substrate 20. The spacer layer 30a has a linear shape in a top view of the wiring substrate 20 and is disposed along the linear portion of the bonding surface 50b between the portion on the first metal layer 31 and the portion on the second metal layer 32. The spacer layer 30b has a C-shape in a top view of the wiring substrate 20 and is disposed along the C-shape portion of the bonding surface 50b between the portion on the first metal layer 31 and the portion on the second metal layer 32. As a result, most of the space between the bonding surface 50b and the metal substrate 28, where the first metal layer 31 and the second metal layer 32 are not disposed, can be filled with the spacer layers 30a and 30b. Therefore, the formation of a gap between the bonding surface 50b and the wiring substrate 20 can be further reduced.

[0073] In this embodiment, the thicknesses of the spacer layers 30a and 30b are equal to the thicknesses of the first metal layer 31 and the second metal layer 32. Furthermore, the first metal layer 31, the second metal layer 32, and the spacer layers 30a and 30b are covered with the second insulating layer 22 of the same thickness. This makes it possible to further flatten the top surface 20a of the wiring substrate 20, thereby further reducing the formation of gaps between the bonding surface 50b and the wiring substrate 20. Furthermore, by covering each metal layer and each spacer layer with the second insulating layer 22, it is possible to reduce the possibility of the metal layers being broken due to contact with an external object.

[0074] Furthermore, the distance (i.e., gap) between each of the spacer layers 30a and 30b and the first metal layer 31 is smaller than the width of the first metal layer 31 (i.e., the dimension in the direction perpendicular to the extension direction and thickness direction of the first metal layer 31). Furthermore, the distance between each of the spacer layers 30a and 30b and the second metal layer 32 is smaller than the width of the second metal layer 32. This further reduces the dimension of the recess formed on the upper surface 20a of the wiring substrate 20. Furthermore, the distance between each of the first metal layer 31 and the second metal layer 32 and the spacer layer 30a may be smaller than the width of the spacer layer 30a. Furthermore, the distance between each of the first metal layer 31 and the second metal layer 32 and the spacer layer 30b may be smaller than the width of the spacer layer 30b. This further reduces the dimension of the recess formed on the upper surface 20a of the wiring substrate 20. Therefore, the formation of a gap between the bonding surface 50b and the wiring substrate 20 can be further reduced. The distance between each of the spacer layers 30a and 30b and the first metal layer 31 may be greater than the thickness of the first metal layer 31. The distance between each of the spacer layers 30a and 30b and the second metal layer 32 may be greater than the thickness of the second metal layer 32. This makes it possible to prevent a short circuit between the first metal layer 31 and the second metal layer when the spacer layers 30a and 30b are made of metal.

[0075] Next, design examples of each metal layer will be described with reference to Figs. 7 to 9. Fig. 7 is a schematic diagram illustrating the dimensions of the first metal layer 31 according to this embodiment. Fig. 8 is a graph showing the relationship between the applied current and the operating voltage and light output of the semiconductor light emitting device 10 according to this embodiment. Fig. 9 is a table showing design examples of the metal layers.

[0076] 7 shows a schematic diagram of a first metal layer 31 as an example of each metal layer. As shown in FIG. 7, the width of a cross section perpendicular to the extension direction of the metal layer is defined as W, the thickness as T, and the length in the extension direction as L. Note that FIG. 7 also shows the first insulating layer 21 on which the first metal layer 31 is disposed. Note that the dimensions of metal layers other than the first metal layer 31 are defined in the same way as the first metal layer 31.

[0077] Electrical wiring made of metal layers has slight (electrical) resistance. However, when supplying power to a semiconductor light-emitting element 41 with a high optical output, the amount of supplied current is large, so even slight resistance in the electrical wiring cannot be ignored. A high-optical-output semiconductor light-emitting element 41 with an optical output of 1 watt or more and 100 watts or less is applied with a current of, for example, 1 ampere or more and 50 amperes or less and a voltage of 2 volts or more and 6 volts or less. For example, when a semiconductor light-emitting element 41 with an applied current of 2 amperes and an operating voltage of 2 volts is used, even if the wiring resistance is 0.1 Ω, the voltage drop in the electrical wiring will be 0.2 V. In other words, the operating voltage will increase by 0.2 V. Therefore, wiring resistance cannot be ignored as a factor in increasing the operating voltage of the semiconductor light-emitting device 10.

[0078] As shown in FIG. 8, when the resistance of the electrical wiring is low relative to the applied current If, the operating voltage is Va (see the thin solid line in FIG. 8). However, when the resistance of the electrical wiring is high, the operating voltage becomes Vb, which is higher than Va (see the dashed line in FIG. 8). When the resistance of the electrical wiring is high, the amount of heat generated in the electrical wiring increases compared to when the resistance is low. This decrease in light output from the semiconductor light-emitting element 41 due to the increased heat generation may be prevented by dissipating heat using a heat sink or the like. However, the Wall-Plug Efficiency, which is the input power-to-light conversion efficiency of the semiconductor light-emitting device 10, decreases from Po / (Va·If) when the resistance of the electrical wiring is low to Po / (Vb·If) when the resistance of the electrical wiring is high. This decrease in conversion efficiency has a significant impact on power consumption, particularly in light source devices using multiple semiconductor light-emitting devices 10.

[0079] A method for reducing the resistance of such electrical wiring made of metal layers will be specifically described below.

[0080] In the prior art, electrical wiring is formed by sintering ceramic and metal layers together, and the metal layers are formed using a conductive paste whose main component is tungsten, a material suitable for sintering together. However, the volume resistivity of tungsten is approximately 5.7 × 10 -8It is relatively large at Ω·m and is likely to cause an increase in wiring resistance.

[0081] In this embodiment, the metal layer has a volume resistivity of approximately 1.8×10 -8 It is made of copper, which has a relatively low resistance of Ω·m, or a material whose main component is copper.

[0082] Furthermore, in the prior art, a metal layer is formed inside the ceramic, which requires high adhesion between the metal layer and the ceramic. Therefore, the thickness T of the metal layer must be smaller than, for example, 50 μm. Alternatively, the thickness T of the metal layer may be smaller than, for example, 20 μm. This reduces the occurrence of unevenness on the surface of the ceramic layer. In such cases, limitations are imposed on the design conditions of the metal layer to reduce the wiring resistance. For example, when tungsten is used as the material for the metal layer, as shown in Figure 9, in Design Example 1, the thickness T and width W of the metal layer are small, resulting in high wiring resistance. As a result, the operating voltage increases by 0.228 V due to the wiring resistance. Therefore, when the applied current is large, the thickness T and width W must be increased, as in Design Example 2.

[0083] In this embodiment, as shown in Design Example 4 in Figure 9, the dimensions of the metal layer are set to be approximately the same as those of Design Example 2 of the prior art, and the material is changed from tungsten in Design Example 2 to copper. This makes it possible to reduce the wiring resistance to approximately one-third of that of Design Example 2. Therefore, it is possible to reduce the voltage increase due to the wiring resistance to 1% or less of the operating voltage.

[0084] Furthermore, by using copper as the material for the metal layer, as shown in Design Example 3, even if the thickness T and width W are the same as those in Design Example 1, the wiring resistance can be reduced to approximately one-third compared to Design Example 1.

[0085] Furthermore, when the applied current is larger as shown in Design Examples 5 and 6 in FIG. 9, an increase in operating voltage due to wiring resistance can be suppressed by increasing at least one of the thickness T and the width W, for example.

[0086] As shown in Design Examples 4 to 6 in FIG. 9 , the thickness T of the metal layers constituting the first metal layer 31 and the second metal layer 32 may be 0.05 mm or more. This reduces the resistance of the first metal layer 31 and the second metal layer 32. Therefore, a convex portion having a height of 0.05 mm or more is formed on the upper surface 20a of the wiring board 20. Even when the second insulating layer 22 is made of a resin such as a resist to cover each metal layer and the first insulating layer 21, the thickness of the second insulating layer 22 is approximately 0.02 mm to 0.1 mm, making it difficult to flatten the upper surface 20a of the wiring board 20. Furthermore, the width of each metal layer may be 1 mm or more. This reduces the wiring resistance of each metal layer. Furthermore, to reduce the wiring resistance, the length of each metal layer must be as short as possible. Therefore, the first metal layer 31 and the second metal layer 32 connect the first pad electrode 31p and the second pad electrode 32p, respectively, to the connector 70 over the shortest distance, for example, in a linear manner. Therefore, the distance between the first metal layer 31 and the second metal layer 32 is, for example, 1 mm or more. In this case, even if the cap unit 50 and the wiring board 20 are joined with the joining member 55, a gap having a space of, for example, about 0.01 mm or more in the thickness direction and about 0.1 mm or more in the width direction will be generated between the cap unit 50 and the wiring board 20. Therefore, the gap between the cap unit 50 and the wiring board 20 cannot be sealed.

[0087] In this embodiment, the spacer layers 30a and 30b can narrow the width of the recesses formed between the metal layers and the spacer layers to, for example, 0.3 mm or less. This allows the bonding material 55 to fill the gap between the cap unit 50 and the wiring substrate 20. Therefore, the gap between the cap unit 50 and the wiring substrate 20 can be sealed.

[0088] Furthermore, wiring board 20 of this embodiment has a simplified configuration because it is not necessary to provide wiring inside the board.

[0089] In this embodiment, the same material as the metal layers is used to form each spacer layer, but the material that can form each spacer layer is not limited to this. For example, in the process shown in Figure 10B, after forming only each metal layer without forming each spacer layer, a resin film such as a polyimide film having a thickness similar to that of each metal layer may be formed and used as the spacer layer. This prevents each metal layer from shorting out with other metal layers via the spacer layer.

[0090] [1-3. Manufacturing method] Next, a method for manufacturing semiconductor light emitting device 10 according to this embodiment will be described. First, a method for manufacturing wiring substrate 20 will be described with reference to Figures 10A to 10G. Figures 10A to 10G are schematic cross-sectional views illustrating each step of the method for manufacturing wiring substrate 20 according to this embodiment.

[0091] First, as shown in FIG. 10A, a flat plate of oxygen-free copper having a thickness of, for example, 2 mm is prepared as metal substrate 28. Next, an insulating substrate 21M made of, for example, epoxy glass prepreg is placed on metal substrate 28 as a material for forming first insulating layer 21. Next, a metal foil 30M made of, for example, copper foil having a thickness of 0.08 mm is placed on insulating substrate 21M as a material for forming each metal layer and each spacer layer. Next, metal substrate 28, insulating substrate 21M, and metal foil 30M are stacked and heated under pressure to form an integrated substrate as shown in FIG. 10A.

[0092] 10B, the metal foil 30M is patterned by etching to form a first metal layer 31, a second metal layer 32, and spacer layers 30a and 30b. Note that the cross section shown in FIG. 10B does not show the first metal layer 31 and the second metal layer 32, but shows the third metal layer 33 and the fourth metal layer 34. In this way, the third metal layer 33 and the fourth metal layer 34 may be formed from the metal foil 30M in this step.

[0093] Subsequently, as shown in FIG. 10C, a resist 22M is formed on the insulating substrate 21M, each metal layer, and each spacer layer.

[0094] 10D, the resist 22M is patterned by a photography method to form the second insulating layer 22. The second insulating layer 22 has the opening 21a of the first insulating layer 21 and openings 22a to 22d for forming the pad electrodes.

[0095] Subsequently, as shown in FIG. 10E, the portion of insulating substrate 21M exposed from opening 22a is removed using laser trimming, thereby forming first insulating layer 21 having opening 21a.

[0096] Subsequently, as shown in FIG. 10F, a protective film 25 made of, for example, Au is formed on the metal surfaces exposed from the opening 21a and the openings 22b to 22d by electroless plating.

[0097] 10G, the metal substrate 28 on which the first insulating layer 21 and other layers have been formed is divided into individual pieces using a cutter CT or the like to form the wiring substrate 20. At this time, by adjusting the blade shape of the cutter CT, it is possible to form obliquely cut surfaces 28c of any shape on the wiring substrate 20. For example, the obliquely cut surfaces 28c can be easily formed by using a rotating blade with a tapered blade.

[0098] Next, a manufacturing method of the cap unit 50 will be described with reference to FIG. 11. FIG. 11 is a schematic perspective view illustrating a manufacturing method of the cap unit 50 according to this embodiment. As shown in FIG. 11, the cap unit 50 is composed of a side wall 51, which is a light-transmitting window, and a holder 52. The side wall 51 is a light-transmitting window formed of an inorganic light-transmitting plate 51a, which is a thin rectangular glass substrate with a thickness Dg of, for example, 0.01 mm or more and 0.2 mm or less, and anti-reflection films 51b and 51c, which are dielectric multilayer films made of SiO2, Ta2O5, TiO2, etc., formed on both sides of the inorganic light-transmitting plate 51a. The holder 52 is a box-shaped component lacking one side wall, with three side walls 52a, 52b, and 52c connected to three sides of the periphery of a transparent rectangular top plate 52d. The holder 52 is manufactured, for example, by forming recesses in a rectangular glass block using a sandblaster or the like and then dividing the block.

[0099] The side wall 51 and the holder 52 are joined by optical contact or laser welding to form a box-shaped cap unit 50.

[0100] The thickness Ds of each side wall of holder 52 is, for example, about 0.3 mm or more and 2 mm or less, which is thicker than side wall 51. Therefore, even if side wall 51 is used that is thinner than side walls 52a, 52b, and 52c, side wall 51 is held by structurally strong holder 52 having relatively thick side walls 52a, 52b, and 52c, so damage to side wall 51 can be suppressed. Furthermore, by making side wall 51 and holder 52 out of the same material, damage due to expansion and contraction caused by temperature can be suppressed.

[0101] Next, a method for attaching the cap unit 50 according to this embodiment to the wiring board 20 will be described with reference to FIGS. 12A and 12B. FIG. 12A is a schematic cross-sectional view illustrating a method for attaching the cap unit 50 according to this embodiment to the wiring board 20. Before attaching the cap unit 50 to the wiring board 20 manufactured by the manufacturing method described above, a semiconductor light-emitting element 41 and a submount 45 are mounted, and metal wires (not shown) are attached in advance. FIG. 12A shows a cross section passing through the optical axis of the semiconductor light-emitting element 41 and perpendicular to the wiring board 20. FIG. 12B is a schematic cross-sectional view of a light source device using the semiconductor light-emitting device 10 according to this embodiment.

[0102] In this embodiment, because the top plate 52d of the cap unit 50 is transparent, as shown in FIG. 12A , the position of the cap unit 50 can be adjusted with high precision without contact between the side wall 51, which is a light-transmitting window, and the emission surface of the semiconductor light-emitting element 41. For example, as shown in FIG. 12A , the position of the cap unit 50 may be adjusted while observing an enlarged image of the cap unit 50 and the semiconductor light-emitting element 41 from above the cap unit 50 using an image observation system 91. This makes it possible to adjust the position of the cap unit 50 so that the distance between the side wall 51 and the emission surface of the semiconductor light-emitting element 41 is less than the thickness of the side wall 51.

[0103] Furthermore, by using the thin sidewalls 51, the distance between the semiconductor light emitting element 41 and the outside of the cap unit 50 can be reduced.

[0104] Furthermore, the wiring board 20 includes a spacer, and the wiring board 20 and the side wall 51 of the cap unit 50 are joined on the spacer. This allows the amount of joining material between the wiring board 20 and the side wall 51 to be small, which prevents excess joining material from reaching the vicinity of the adjacent semiconductor light emitting element 41 and changing the characteristics of the emitted light L1.

[0105] 12B, in a light source device including a semiconductor light emitting device 10 and a lens optical element 92 that is a fast-axis collimating lens, the distance DL between the emission surface of the semiconductor light emitting device 41 and the lens optical element 92 can be reduced by reducing the distance between the semiconductor light emitting device 41 and the lens optical element 92. This reduces the beam width in the fast-axis direction of the laser light (emitted light L1) emitted from the semiconductor light emitting device 10.

[0106] In this case, it is better that the sum of the thickness Dg of the side wall 51 and the distance Dgap from the side wall 51 to the light-emitting surface is short. By making the distance Dgap smaller than the thickness Dg of the side wall 51, the lens optical element 92 can be brought closer to the light-emitting surface of the semiconductor light-emitting element 41 while maintaining the strength of the side wall 51.

[0107] With the above-described configuration, the semiconductor light emitting device 10 of this embodiment can apply a large current to the semiconductor light emitting element 41 with a small wiring resistance to emit emitted light L1 with a large optical output. Furthermore, since the semiconductor light emitting element 41 on the wiring substrate 20 is sealed with the cap unit 50, the reliability of the semiconductor light emitting element 41 can be improved. Furthermore, the distance between the light emitting point 41e of the semiconductor light emitting element 41 and the outside of the cap unit 50 is reduced. This allows for more flexible design of external optical elements, such as lens optical elements, that are disposed outside the semiconductor light emitting device 10 and optically coupled to the light emitting point 41e. Furthermore, as shown in FIG. 4, an obliquely cut surface 28c is formed at the end of the metal substrate 28 of the wiring substrate on the side of the upper surface 20a. This prevents part of the emitted light L1 from being reflected outside the semiconductor light emitting device. hairThis configuration suppresses heat buildup and allows for more flexible placement of external optical elements. Furthermore, Joule heat generated in the semiconductor light-emitting element 41 spreads through the metal substrate 28 and is dissipated from the heat dissipation surface 20b to an external heat sink. Because the semiconductor light-emitting element 41 is mounted on the metal substrate 28 without the first insulating layer 21 or the second insulating layer 22, Joule heat is efficiently transferred to the metal substrate 28. Furthermore, the obliquely cut surfaces 28c at the end of the metal substrate 28 make the area of ​​the lower surface larger than the area of ​​the upper surface. Therefore, the generated Joule heat is transferred from the submount 45 to the metal substrate 28, as indicated by heat flows TP1 and TP5 in FIG. 4, and then spreads in a direction parallel to the upper surface of the metal substrate 28, allowing for efficient external dissipation. Therefore, the semiconductor light-emitting element 41 can emit light L1 with a higher optical output.

[0108] [Variation 1] Next, a semiconductor light emitting device according to Modification 1 of the present embodiment will be described. The semiconductor light emitting device according to this modification differs from the semiconductor light emitting device 10 according to Embodiment 1 in the configuration of the spacer layer, but is the same in other configurations. The semiconductor light emitting device according to this modification will be described below with reference to FIG. 13A, focusing on the differences from the semiconductor light emitting device 10 according to Embodiment 1.

[0109] FIG. 13A is a schematic top view showing the structure of spacer layers 130a and 130b of a semiconductor light-emitting device 110 according to this modification. FIG. 13A shows the semiconductor light-emitting element 41 and its surroundings of the semiconductor light-emitting device 110 with the cap unit 50 and the second insulating layer 22 removed. As shown in FIG. 13A, the spacer layers 130a and 130b according to this modification are made of the same material as the second metal layer 32 and are electrically connected to the second metal layer 32. More specifically, the spacer layers 130a and 130b and the second metal layer 32 have the same thickness, and the top surfaces of the spacer layers and the second metal layer 32 are connected flatly. In other words, the top surfaces of the spacer layers and the second metal layer 32 are connected flush with each other. The boundaries between the second metal layer 32 and each spacer layer may be set as appropriate. In this embodiment, the second metal layer 32 is defined as a rectangular portion extending in the optical axis direction. The spacer layer 130a is disposed on the side of the rear end face 41R opposite to the emission surface 41F including the light-emitting point 41e of the semiconductor light-emitting element 41, so as to extend from one edge of the second metal layer 32 (the side closer to the first metal layer 31) to the other side of the first metal layer 31 (the side closer to the second metal layer 32). In other words, the spacer layer 130a is a portion that protrudes from the second metal layer 32 to one side (in a direction approaching the first metal layer 31). The spacer layer 130b is composed of five portions. The first portion of the spacer layer 130b is disposed on the side of the rear end face 41R, so as to extend laterally (in the plane of the main surface of the wiring substrate 20, in a direction perpendicular to the optical axis direction) from one side of the first metal layer 31 (the side farther from the second metal layer 32). The second portion of the spacer layer 130b is connected to the first portion and is disposed to extend in the optical axis direction on one side (the side farther from the second metal layer 32) of the first pad electrode 31p and the first metal layer 31. The third portion of the spacer layer 130b is connected to the second portion and is disposed to extend in the horizontal direction on the side of the emission surface 41F. The fourth portion of the spacer layer 130b is connected to the third portion and is disposed to extend in the optical axis direction on the other side (the side farther from the first metal layer 31) of the second pad electrode 32p and the second metal layer 32.The fifth portion of the spacer layer 130b is connected to the fourth portion and is disposed on the side of the rear end face 41R so as to extend laterally from the other edge (the side farther from the first metal layer 31) of the second metal layer 32. As with the spacer layers according to the first embodiment, these spacer layers 130a and 130b can be formed simultaneously with the second metal layer 32 in the process of forming each metal layer. Note that even when each spacer layer is in contact with the second metal layer 32 as in this modification, each spacer layer is disposed at a position different from the second metal layer 32.

[0110] According to the spacer layers 130a and 130b of this modification, the gap between the second metal layer 32 and each spacer layer is zero, so that no recesses are formed on the upper surface of the wiring substrate at positions corresponding to the gaps between the second metal layer 32 and each spacer layer. This reduces the likelihood of a gap being formed between the bonding surface 50b of the cap unit 50 and the upper surface of the wiring substrate. In other words, the bonding surface 50b of the cap unit 50 and the upper surface of the wiring substrate can be more reliably sealed.

[0111] In this modification, each spacer layer is connected to the second metal layer 32, but each spacer layer may be connected to the first metal layer 31. In this case, the spacer layers 130a and 130b may be made of the same material as the first metal layer 31. In other words, the spacer layers 130a and 130b may be made of the same material as the first metal layer 31 or the second metal layer 32 and may be electrically connected to the first metal layer 31 or the second metal layer 32.

[0112] [Variation 2] Next, a semiconductor light emitting device according to Modification 2 of the present embodiment will be described. The semiconductor light emitting device according to this modification differs from the semiconductor light emitting device 10 according to embodiment 1 in the configuration of the spacer layer, but is the same in other configurations. The semiconductor light emitting device according to this modification will be described below with reference to FIG. 13B, focusing on the differences from the semiconductor light emitting device 10 according to embodiment 1.

[0113] FIG. 13B is a schematic top view showing the configuration of the spacer layers 30a, 30b, and 30c of the semiconductor light-emitting device 110a according to this modification. FIG. 13B shows the semiconductor light-emitting element 41 and its surroundings of the semiconductor light-emitting device 110a with the cap unit 50 and the second insulating layer 22 removed. As shown in FIG. 13B, the semiconductor light-emitting device 110a according to this modification includes four spacer layers 30c in addition to the spacer layers 30a and 30b similar to those in the first embodiment. The spacer layers 30c are insulating films disposed between each metal layer and the spacer layers 30a and 30b. The spacer layers 30c may be made of inorganic materials such as resin or low-melting-point glass. When the spacer layers 30a and 30b are made of insulating materials, the spacer layer 30c may be made of a metal material.

[0114] In the wiring board according to this modification, the gaps between each metal layer and the spacer layers 30a and 30b can be filled with the spacer layer 30c, so the dimensions of the recesses formed on the upper surface of the wiring board can be reduced compared to the wiring board 20 according to the first embodiment. This reduces the possibility of a gap being formed between the bonding surface 50b of the cap unit 50 and the upper surface of the wiring board. In other words, the bonding surface 50b of the cap unit 50 and the upper surface of the wiring board can be more reliably sealed.

[0115] Furthermore, the thickness of the spacer layer 30c may be the same as that of each of the metal layers and the spacer layers 30a and 30b, thereby further reducing the dimensions of the recess formed on the upper surface of the wiring substrate.

[0116] [Variation 3] Next, a semiconductor light emitting device according to Modification 3 of the present embodiment will be described. The semiconductor light emitting device according to this modification differs from the semiconductor light emitting device 10 according to embodiment 1 in that it includes a shielding member disposed between the temperature detection element 60 and the semiconductor light emitting element 41, but is the same in other respects. The semiconductor light emitting device according to this modification will be described below with reference to FIGS. 14A and 14B, focusing on the differences from the semiconductor light emitting device 10 according to embodiment 1.

[0117] 14A and 14B are a schematic top view and a cross-sectional view, respectively, showing the positional relationship between the semiconductor light emitting element 41, the temperature detection element 60, and the shielding member 60s of a semiconductor light emitting device 110b according to this modification. FIG. 14B is a cross-sectional view taken along the optical axis LA1 of the semiconductor light emitting element 41 of FIG. 14A. As shown in FIGS. 14A and 14B, the semiconductor light emitting device 110b according to this modification includes a shielding member 60s disposed between the temperature detection element 60 and the semiconductor light emitting element 41.

[0118] As shown in FIG. 14B, the semiconductor light-emitting element 41 also emits output light L1B from the rear end face 41R, which is the end face opposite to the output face where the light-emitting point 41e is located. The intensity of this output light L1B is significantly lower than that of the output light L1. However, if the semiconductor light-emitting element 41 is a high-light-output element, the intensity of the output light L1B will also be relatively high. Therefore, when the output light L1B is irradiated onto the temperature detection element 60, the temperature of the temperature detection element 60 increases, making it impossible to accurately detect the temperature of the wiring substrate 20. In this modification, a shielding member 60s is disposed between the temperature detection element 60 and the rear end face 41R of the semiconductor light-emitting element 41. In other words, the semiconductor light-emitting element 41, the shielding member 60s, and the temperature detection element 60 are disposed in this order on the optical axis LA1. This allows the output light L1B to be blocked by the shielding member 60s. Furthermore, the shielding member 60s is not particularly limited as long as it can shield the emitted light L1B, and may be, for example, the same element as the temperature detection element 60. When such an element is used as the shielding member 60s, no wiring is connected to the element. By disposing an element having the same dimensions as the temperature detection element 60 between the temperature detection element 60 and the semiconductor light emitting element 41, it is possible to reliably reduce irradiation of the temperature detection element 60 with the emitted light L1B. Furthermore, the dimensions of the shielding member 60s may be larger than those of the temperature detection element 60. This further reliably reduces incidence of the emitted light L1B on the temperature detection element 60. It is noted that the shielding member 60s may be disposed outside or inside the cap unit 50.

[0119] (Embodiment 2) Next, a semiconductor light emitting device according to embodiment 2 will be described. The semiconductor light emitting device according to this embodiment differs from the semiconductor light emitting device 10 according to embodiment 1 mainly in the configurations of the first metal layer and the second metal layer. Below, the semiconductor light emitting device according to this embodiment will be described, focusing on the differences from the semiconductor light emitting device 10 according to embodiment 1.

[0120] [2-1. Overall composition] First, the overall configuration of the semiconductor light emitting device according to this embodiment will be described with reference to Figures 15 to 17. Figures 15 and 16 are a schematic perspective view and an exploded perspective view, respectively, showing the overall configuration of semiconductor light emitting device 210 according to this embodiment. Figure 17 is a schematic cross-sectional view showing the overall configuration of semiconductor light emitting device 210 according to this embodiment. Figure 17 shows a cross section taken along line XVII-XVII in Figure 16, which is perpendicular to upper surface 220a of wiring substrate 220.

[0121] 15 to 17, a semiconductor light emitting device 210 according to this embodiment includes a wiring substrate 220, a cap unit 50, and a connector 270. As shown in FIGS. 16 and 17, the semiconductor light emitting device 210 further includes a semiconductor light emitting element 41, a submount 45, and a temperature detection element 60. As shown in FIG. 17, the semiconductor light emitting device 210 further includes bonding members 226, 42, and 62, and a bonding layer 255. Each component of the semiconductor light emitting device 210 will now be described.

[0122] 17, the wiring board 220 according to this embodiment includes a metal substrate 228, a first insulating layer 221, a second insulating layer 222, a third metal layer 233, a fourth metal layer 234, and a protective film 225. 2 As shown in FIG. 16, the semiconductor device 20 further includes a first metal layer 231, a second metal layer 232, spacer layers 230a, 230b, and 230c, a first pad electrode 231p, a second pad electrode 232p, a first extraction electrode 237, and a second extraction electrode 238.

[0123] In the present embodiment, as in the first embodiment, through holes 228a and 228b and positioning holes 229a and 229b are formed in wiring substrate 220. The through holes 228a and 228b and positioning holes 229a and 229b according to the present embodiment are arranged differently on wiring substrate 220 than the through holes 28a and 28b and positioning holes 29a and 29b according to the first embodiment. In the present embodiment, positioning holes 229a and 229b are arranged near the rear end of wiring substrate 220. Herein, the rear end of wiring substrate 220 refers to the end farther from light-emitting point 41e of the two ends of wiring substrate 220 in the propagation direction of emitted light L1. Hereinafter, the side of semiconductor light-emitting element 41 along which emitted light L1 propagates will be referred to as the front, and the opposite direction from the front will be referred to as the rear. The through holes 228a and 228b are disposed near the center of the wiring substrate 220 in the propagation direction of the emitted light L1.

[0124] The metal substrate 228 differs from the metal substrate 28 according to the first embodiment in the number and arrangement of the holes provided. others They agree on the following points.

[0125] The first insulating layer 221 is an insulating layer having the same configuration as the first insulating layer 21 according to the first embodiment, and has an opening 221a formed therein.

[0126] The first metal layer 231, the second metal layer 232, the third metal layer 233, and the fourth metal layer 234 are metal layers that are spaced apart from one another on the first insulating layer 221. In the present embodiment, as shown in FIG. 16 , the first metal layer 231 extends from the first pad electrode 231p in a direction perpendicular to the propagation direction of the emitted light L1 and parallel to the main surface of the metal substrate 228, and is connected to the first extension electrode 237. Specifically, the first metal layer 231 extends from between the first pad electrode 231p and the first insulating layer 221 to between the first extension electrode 237 and the first insulating layer 221. As shown in FIG. 16 , the second metal layer 232 extends from the second pad electrode 232p in a direction perpendicular to the propagation direction of the emitted light L1 and parallel to the main surface of the metal substrate 228, and is connected to the second extension electrode 238. Specifically, the second metal layer 232 extends from between the second pad electrode 232p and the first insulating layer 221 to between the second extraction electrode 238 and the first insulating layer 221. The second metal layer 232 extends in the opposite direction to the extension direction of the first metal layer 231. As described above, in this embodiment, the first metal layer 231 and the second metal layer 232 are not connected to the connector 270. Current is supplied to the semiconductor light emitting element 41 via the first extraction electrode 237 and the second extraction electrode 238, without via the connector 270. The first metal layer 231 and the second metal layer 232 have a structure as shown in Design Example 6 in FIG. 9 . That is, the first metal layer 231 and the second metal layer 232 are copper films having a thickness T of 0.070 mm, a width W of 7.0 mm, and a length L of 5 mm. This allows the resistance of the first metal layer 231 and the second metal layer 232 to be 0.0002 Ω. Therefore, even when a large current of about 30 A is supplied to the semiconductor light emitting element 41, the increase in operating voltage due to the resistance of each metal layer can be suppressed to about 0.006 V.

[0127] The third metal layer 233 and the fourth metal layer 234 are wirings connected to the temperature detection element 60, similar to the third metal layer 33 and the fourth metal layer 34 in the first embodiment. In the present embodiment, as shown in FIGS. 16 and 17 , the temperature detection element 60 is disposed inside the cap unit 50, and therefore the arrangement of the third metal layer 233 and the fourth metal layer 234 on the wiring substrate 220 differs from the third metal layer 33 and the fourth metal layer 34 in the first embodiment. In the present embodiment, as shown in FIG. 16 , the third metal layer 233 and the fourth metal layer 234 are disposed to extend in the optical axis direction on the side of the rear end face 41R opposite to the emission surface 41F of the semiconductor light emitting element 41. A bonding surface 50b of the cap unit 50 bonded to the wiring substrate 220 intersects with the third metal layer 233 and the fourth metal layer 234 in a top view of the wiring substrate 220.

[0128] As shown in FIG. 16, the first pad electrode 231p and the second pad electrode 232p have the same configurations as the first pad electrode 31p and the second pad electrode 32p according to the first embodiment, respectively.

[0129] 16, the spacer layers 230a, 230b, and 230c are layers that are disposed at positions different from the first metal layer 231 and the second metal layer 232 on the first insulating layer 221. Like the spacer layers according to the first embodiment, the spacer layers 230a, 230b, and 230c are disposed between the bonding surface 50b of the cap unit 50 with the wiring substrate 220 and the first insulating layer 221. Like the metal layers, each spacer layer forms a convex portion on the first insulating layer 221.

[0130] The spacer layer 230a has an L-shape in a top view of the wiring substrate 220 and is composed of two parts. The first part of the spacer layer 230a is arranged on one side of the semiconductor light emitting element 41 (the side on which the first metal layer 231 of the semiconductor light emitting element 41 is arranged) so as to extend in the optical axis direction from the rear end face 41R side of the first metal layer 231. The second part of the spacer layer 230a is connected to the first part and is arranged on the side of the rear end face 41R so as to extend laterally from one side of the third metal layer 233. The spacer layer 230b has an L-shape in a top view of the wiring substrate 220 and is composed of two parts. The first part of the spacer layer 230b is arranged on the other side of the semiconductor light emitting element 41 (the side on which the second metal layer 232 of the semiconductor light emitting element 41 is arranged) so as to extend in the optical axis direction from the rear end face 41R side of the second metal layer 232. The second portion of the spacer layer 230b is connected to the first portion and is disposed on the side of the rear end face 41R, extending laterally from the other side of the fourth metal layer 234. The spacer layer 230c is composed of three portions. The first portion of the spacer layer 230c is disposed on one side of the semiconductor light emitting element 41, extending from the emission surface 41F side of the first metal layer 231 in the optical axis direction. The second portion of the spacer layer 230c is connected to the first portion and is disposed on the side of the emission surface 41F, extending laterally. The third portion of the spacer layer 230c is connected to the second portion and is disposed on the other side of the semiconductor light emitting element 41, extending from the emission surface 41F side of the second metal layer 232 in the optical axis direction.

[0131] 17, the second insulating layer 222 is an insulating layer disposed on the first insulating layer 221. 2 Similar to the second insulating layer 22 according to the first embodiment, the insulating layer 22 covers at least a part of the first metal layer 231, the second metal layer 232, the third metal layer 233, the fourth metal layer 234, and the spacer layers 230a, 230b, and 230c.

[0132] 17, the protective film 225 is a metal film disposed in a position on the wiring substrate 220 where the submount 45 is to be bonded. Similar to the protective film 25 according to the first embodiment, the protective film 225 is disposed in a region corresponding to the opening 221a of the first insulating layer 221 of the metal substrate 228. Similar to the protective film 35 according to the first embodiment, the protective film 235 is disposed on a portion of the upper surfaces of the first metal layer 231, the second metal layer 232, the third metal layer 233, and the fourth metal layer 234. In this embodiment, the submount 45 is disposed inside the opening 221a of the first insulating layer 221 and is mounted on the metal substrate 228 via the bonding member 226 and the protective film 225. The bonding member 226 is made of, for example, AuSn solder.

[0133] The first extension electrode 237 and the second extension electrode 238 are examples of extension electrodes electrically connected to the first metal layer 231 and the second metal layer 232, respectively. In the present embodiment, the first extension electrode 237 and the second extension electrode 238 are disposed on the first metal layer 231 and the second metal layer 232, respectively. The first extension electrode 237 and the second extension electrode 238 are disposed near the first pad electrode 231p and the second pad electrode 232p, respectively. This allows the lengths of the first metal layer 231 and the second metal layer 232 to be shortened, thereby reducing the resistance of the first metal layer 231 and the second metal layer 232.

[0134] The first extension electrode 237 and the second extension electrode 238 each have an annular shape, and have electrode through-holes 237a and 238a formed in the center thereof, respectively, that penetrate the wiring substrate 220. The through-holes 228a and 228b are holes for inserting fixing members such as screws when closely fixing the wiring substrate 220 to a heat sink or the like. In this embodiment, the electrode through-holes 237a and 238a are respectively arranged on one side and the other opposite side of an area of ​​the wiring substrate 220 where the semiconductor light emitting element 41 is arranged. In other words, the semiconductor light emitting element 41 is arranged between the electrode through-hole 237a and the electrode through-hole 238a.

[0135] The bonding layer 255 is a member that bonds the bonding surface 50b of the cap unit 50 and the upper surface 220a of the wiring substrate 220. In the present embodiment, the bonding layer 255 includes a first preliminary bonding film 255a, a bonding member 255b, and a second preliminary bonding film 255c. The first preliminary bonding film 255a and the second preliminary bonding film 255c are metal films that are disposed on the bonding surface 50b and the upper surface of the second insulating layer 222, respectively, and are made of Ni, Au, or the like. These preliminary bonding films enable the cap unit 50 and the second insulating layer 222 to be easily bonded with the bonding member 255b. The bonding member 255b is an alloy member made of AuSn solder or the like.

[0136] The temperature detection element 60 is the same as the temperature detection element 60 according to the first embodiment. In this embodiment, the temperature detection element 60 is covered by a cap unit 50, as shown in FIGS. 16 and 17. This prevents the temperature detection element 60 from being exposed to the outside air, suppressing the influence of the outside air on temperature detection, thereby enabling accurate temperature detection. The arrangement of the temperature detection element 60 according to this embodiment will be described below with reference to FIG. 18. FIG. 18 is a top view showing the arrangement of the temperature detection element 60 according to this embodiment.

[0137] 18, the temperature detection element 60 according to this embodiment is disposed at a position that does not intersect with the optical axis LA1 of the semiconductor light emitting element 41. This prevents the emitted light L1B emitted from the rear end face 41R of the semiconductor light emitting element 41 from irradiating the temperature detection element 60 without disposing a shielding member. Therefore, the temperature of the wiring substrate 220 can be detected with high accuracy by the temperature detection element 60.

[0138] Connector 270 is a connection component having terminals connected to third metal layer 233 and fourth metal layer 234. In the present embodiment, connector 270 does not have terminals connected to first metal layer 231 and second metal layer 232, unlike connector 70 according to the first embodiment.

[0139] [2-2. Effects] Next, the effects of the semiconductor light emitting device 210 according to this embodiment will be described with reference to FIGS. 19A to 19C. Each of FIGS. 19A to 19C is a schematic cross-sectional view illustrating a method for bonding the cap unit 50 of the semiconductor light emitting device 210 according to this embodiment to the wiring substrate 220. FIG. 19A shows a cross-section similar to FIG. 17, but omits components other than the wiring substrate 220 and the cap unit 50. Also, FIGS. 19B and 19C show the semiconductor light emitting device 210 in a cross-section taken along line XIX-XIX in FIG. 16, which is perpendicular to the upper surface 220a of the wiring substrate 220. FIGS. 19A and 19B show a state before the cap unit 50 and the wiring substrate 220 are bonded, and FIG. 19C shows a state after the cap unit 50 and the wiring substrate 220 have been bonded.

[0140] 19A and 19B, a first bonding preliminary film 255a and a bonding member 255b are formed in this order on the bonding surface 50b of the cap unit 50. Meanwhile, a second bonding preliminary film 255c is formed on the upper surface 220a of the wiring substrate 220 in a region facing the bonding surface 50b of the cap unit 50. As shown in FIG. 19B, in the present embodiment as well, the dimensions of the recesses formed on the upper surface 220a of the wiring substrate 220 can be reduced by the spacer layers, as in the first embodiment.

[0141] Next, the cap unit 50 is placed on the upper surface 220a of the wiring substrate 220. Next, the wiring substrate 220 is heated to melt the bonding member 255b between the first bonding preliminary film 255a and the second bonding preliminary film 255c. Next, the wiring substrate 220 is cooled to solidify the bonding member 255b. As a result, as shown in FIG. 19C, the first bonding preliminary film 255a and the second bonding preliminary film 255c can be bonded by the bonding member 255b. At this time, as described above, the dimensions of the recess formed on the upper surface 220a of the wiring substrate 220 are reduced, so that the recess formed on the upper surface 220a of the wiring substrate 220 can be filled with the bonding member 255b as shown in FIG. 19C. Therefore, the gap between the cap unit 50 and the wiring substrate 220 can be sealed. Therefore, in this embodiment as well, a semiconductor light emitting device 210 with high light output and high reliability can be realized, as in the first embodiment.

[0142] [2-3.Light source device] Next, a light source device using a semiconductor light emitting device 210 according to this embodiment will be described with reference to Figures 20 and 21. Figures 20 and 21 are a schematic perspective view and an exploded perspective view, respectively, showing the configuration of a light source device 201 according to this embodiment.

[0143] 20 and 21, light source device 201 includes semiconductor light emitting device 210, heat sink 219, terminal fixing screws S1 and S2, and fixing screws S3 and S4. In this embodiment, light source device 201 further includes cable 272 having connector 271, and cables 211 and 212 having terminals 213 and 214, respectively.

[0144] Heat sink 219 is a heat dissipation component made of a material with high thermal conductivity, such as metal. Heat sink 219 is made of, for example, iron, iron alloy, aluminum, aluminum alloy, copper, or the like. Furthermore, heat sink 219 may be made of a surface-treated material, such as an aluminum alloy with an anodized surface or copper with Ni plating. As shown in FIG. 21 , heat sink 219 has positioning pins P1 and P2 and screw holes T1 to T4 formed therein. Positioning pins P1 and P2 are inserted into positioning holes 229a and 229b of semiconductor light emitting device 210, respectively.

[0145] The semiconductor light emitting device 210 is fixed in close contact with the heat sink 219 using terminal fixing screws S1 and S2 and fixing screws S3 and S4. Specifically, the fixing screws S3 and S4 pass through through holes 228a and 228b in the wiring board, respectively, and are fixed into screw holes T3 and T4 in the heat sink 219, respectively.

[0146] Furthermore, the terminal fixing screw S1 passes through a hole formed in the terminal 213 and the electrode through-hole 237a of the wiring substrate 220, and is fixed into the screw hole T1 of the heat sink 219. The terminal fixing screw S1 passes through the electrode through-hole 237a, and the terminal 213 is disposed between the terminal fixing screw S1 and the first extension electrode 237. This electrically connects the first extension electrode 237 and the terminal 213.

[0147] Furthermore, the terminal fixing screw S2 is fixed into the screw hole T2 of the heat sink 219 via a hole formed in the terminal 214 and the electrode through-hole 238a of the wiring substrate 220. The terminal fixing screw S2 passes through the electrode through-hole 238a, and the terminal 214 is disposed between the terminal fixing screw S2 and the second extension electrode 238. This electrically connects the second extension electrode 238 and the terminal 214.

[0148] As described above, semiconductor light emitting device 210 can be fixed to heat sink 219. In this way, semiconductor light emitting device 210 can be firmly fixed to heat sink 219 using terminal fixing screws S1 and S2 and fixing screws S3 and S4, and therefore heat generated in semiconductor light emitting element 41 of semiconductor light emitting device 210 can be effectively dissipated from metal substrate 228 to heat sink 219.

[0149] Furthermore, with the above configuration, the terminals 213 and 214 can be electrically connected to the first output electrode 237 and the second output electrode 238, respectively. Therefore, a large current can be supplied to the semiconductor light emitting device 210 via the cables 211 and 212.

[0150] The fixing screws S3 and S4 are made of, for example, a metal material, while the terminal fixing screws S1 and S2 are made of an insulating material such as plastic or ceramic, or are coated with an insulating material, in order to prevent short circuits between the terminals and the metal substrate 228 or heat sink.

[0151] Furthermore, the connector 271 is connected to the connector 270. This allows a signal from the temperature detection element 60 to be acquired via the cable 272.

[0152] [Variation 1] Next, a first modified example of the light source device according to the present embodiment will be described. The light source device according to this modified example has a configuration such as a terminal fixing screw for more firmly fixing the semiconductor light emitting device 210 to the heat sink 219 or the like. The configuration of the terminal fixing screw and the like of the light source device according to this modified example will be described below with reference to FIGS. 22A and 22B. FIG. 22A is a schematic cross-sectional view showing a state in which the terminal fixing screw Sc1 according to this modified example is fixed to the heat sink 219. FIG. 22B is an exploded cross-sectional view showing a method for fixing the terminal fixing screw Sc1 according to this modified example to the heat sink 219.

[0153] In this modification, the heat sink 219 has a conductive surface, such as an aluminum alloy that has not been subjected to a surface treatment. In this modification, the terminal 213 and the wiring board 220 are fixed in a screw hole T1 or the like in the heat sink 219 using a terminal fixing screw Sc1 made of a conductive material such as iron or stainless steel. In this case, as shown in FIGS. 22A and 22B , a ring-shaped washer Wi (i.e., a spacer) made of an insulating material is inserted between the terminal fixing screw Sc1 and the terminal 213. This prevents the terminal 213 and the heat sink 219 from shorting out via the terminal fixing screw Sc1. In this modification, the washer Wi is a flanged washer with a flange WiC. By using a flanged washer, a portion of the washer Wi can be disposed inside the through-hole of the terminal 213 or inside the electrode through-hole 237a of the wiring board, thereby reducing the possibility of a short circuit occurring inside the hole between the terminal fixing screw Sc1 and the terminal 213, or between the terminal fixing screw Sc1 and the first extraction electrode 237. Short circuits are similarly suppressed between the terminal 214 and the heat sink 219, and the terminal 214 and the wiring board 220 can be fixed to the heat sink 219, which is also made of a metal material, with the terminal fixing screw made of a metal material.

[0154] This allows the semiconductor light emitting device 210 and the heat sink 219 to be fixed more firmly and to be closely attached to each other. Therefore, heat can be dissipated more efficiently from the semiconductor light emitting elements 41 of the semiconductor light emitting device 210 to the heat sink 219.

[0155] (Embodiment 3) Next, a semiconductor light emitting device according to a third embodiment will be described. The semiconductor light emitting device according to this embodiment differs from the semiconductor light emitting device 210 according to the second embodiment in the direction in which emitted light is extracted. The semiconductor light emitting device according to this embodiment will be described below with reference to FIGS. 23 to 25, focusing on the differences from the semiconductor light emitting device 210 according to the second embodiment. FIGS. 23, 24, and 25 are a schematic perspective view, an exploded perspective view, and a cross-sectional view, respectively, showing the overall configuration of the semiconductor light emitting device 310 according to this embodiment. FIG. 25 is a cross-sectional view of the semiconductor light emitting device 310 shown in FIG.4 25 shows a part of the cross section of the semiconductor light emitting device 310 taken along the line XXV-XXV in FIG. 25. Also, in FIG. 25, the semiconductor light emitting device 310 is shown in a state before the cap unit 350 is bonded to the wiring substrate 220.

[0156] As shown in FIGS. 23 and 24 , a semiconductor light emitting device 310 according to this embodiment includes a wiring substrate 220, a cap unit 350, and a connector 270. As shown in FIG. 24 , the semiconductor light emitting device 310 further includes a semiconductor light emitting element 41, a submount 45, a reflective optical element 358, and a temperature detection element 60. As shown in FIGS. 23 and 25 , the semiconductor light emitting device 310 according to this embodiment emits light L1 emitted by the semiconductor light emitting element 41 in a direction perpendicular to the upper surface 220a of the wiring substrate 220. Specifically, as shown in FIG. 25 , the semiconductor light emitting device 310 includes a reflective optical element 358, and the emitted light L1 from the semiconductor light emitting element 41 is reflected by the reflective optical element 358 and propagates in a direction perpendicular to the upper surface 220a of the wiring substrate 220. Specifically, a reflective surface 358r of the reflective optical element 358 is disposed opposite to the light emitting surface of the semiconductor light emitting element 41. The reflecting surface 358r is inclined at 45 degrees with respect to the optical axis of the semiconductor light emitting element 41. As a result, the emitted light L1 is reflected by the reflecting surface 358r and propagates in a direction perpendicular to the upper surface 220a of the wiring substrate 220 and away from the wiring substrate 220.

[0157] As shown in FIG. 25, the reflective optical element 358 is bonded to the protective film 225 of the opening 221a via a bonding preliminary film 359 having a configuration similar to that of the first bonding preliminary film 255a and a bonding member 226.

[0158] As shown in FIG. 24 , the cap unit 350 according to this embodiment has a transparent rectangular top plate 351 and a holder 352. The top plate 351 is a light-transmitting window having a configuration similar to that of the side wall 51 of the cap unit 50 according to the second embodiment. That is, the top plate 351 is a light-transmitting window having an inorganic light-transmitting plate and an anti-reflection film formed on the inorganic light-transmitting plate. As a result, the light L1 emitted from the semiconductor light-emitting element 41 passes through the top plate 351, which is a light-transmitting window. The holder 352 is a frame-shaped member having four side walls connected to the four sides of the periphery of the top plate 351.

[0159] With the above configuration, the emitted light L1 from the semiconductor light emitting element 41 can be easily extracted to the outside from the upper surface of the cap unit 350.

[0160] The cap unit 350 is formed, for example, by joining a top plate 351 to a frame-shaped holder 352 by optical contact or laser welding. Therefore, the top plate 351 and the periphery of the holder 352 are in close contact with each other. In addition, a first bonding preliminary film (not shown) is arranged on the surface of the holder 352 facing the top plate 351.

[0161] In the semiconductor light emitting device 310 according to the present embodiment, each spacer layer is disposed between the first insulating layer 221 and the bonding surface of the cap unit 350 that is to be bonded to the upper surface 220a of the wiring substrate 220. A second bonding preliminary film 255c is disposed on each spacer layer. By bonding the holder 352 and the wiring substrate 220 with an adhesive, the gap between the cap unit 350 and the wiring substrate 220 can be sealed. As a result, the semiconductor light emitting device 310 according to the present embodiment also achieves the same effects as the semiconductor light emitting device 210 according to the second embodiment.

[0162] The structure between the cap unit 350 and the wiring substrate 220 may be the same as that in the first embodiment.

[0163] In the above embodiment, an example has been shown in which the semiconductor light emitting device 310 includes one semiconductor light emitting element 41, but the semiconductor light emitting device 310 may include a plurality of semiconductor light emitting elements 41 (see FIG. 26 described later). In this case, a reflective optical element may be disposed at a position facing the light emitting surface of each of the plurality of semiconductor light emitting elements 41. The plurality of semiconductor light emitting elements 41 may be disposed in an array or a matrix.

[0164] In the above embodiment, a reflective optical element having a reflective surface tilted at 45 degrees with respect to the optical axis is disposed opposite the emission surface of the semiconductor light-emitting element 41. However, other optical elements may be disposed. For example, a reflective optical element may be disposed in which a wavelength conversion member, such as a phosphor layer, is disposed on a reflective mirror surface tilted at an angle between 10 degrees and 80 degrees with respect to the optical axis. In this case, the semiconductor light-emitting element 41 may be, for example, a semiconductor laser element using a nitride semiconductor material whose emitted light L1 has a peak wavelength in the wavelength range of approximately 380 nm to 490 nm. With this configuration, by wavelength-converting a portion of the emitted light L1 from the semiconductor light-emitting element 41 using the reflective optical element, light including a portion of the emitted light L1 and wavelength-converted light can be emitted from the top plate 351 of the semiconductor light-emitting device 310. More specifically, the emitted light L1 may be light having a wavelength in the blue region, and the wavelength-converted light may be light having a wavelength in the yellow region. This allows for a highly reliable semiconductor light-emitting device to be realized.

[0165] Furthermore, a diffractive optical element or a diffusing optical element may be used as the reflective optical element. This allows the emitted light L1 from the semiconductor light emitting element 41 to be emitted from the top plate 351 in any direction and in a predetermined emission pattern by the reflective optical element. In this case, by using emitted light L1 having a wavelength in the 900 nm band, for example, it is possible to realize a semiconductor light emitting device 310 that emits high-power infrared light and has high reliability. Such a semiconductor light emitting device 310 can be used, for example, in a Lidar (light detection and ranging) device.

[0166] [Variations] Next, a semiconductor light emitting device according to a modification of the present embodiment will be described. The semiconductor light emitting device according to this modification includes a plurality of semiconductor light emitting elements. A reflective optical element is disposed at a position facing the light emitting surface of each of the plurality of semiconductor light emitting elements 41. The plurality of semiconductor light emitting elements 41 and the reflective optical element are disposed in a matrix. The configuration of the semiconductor light emitting device according to this modification will be described below with reference to FIG. 26.

[0167] Fig. 26 is a schematic top view showing the overall configuration of a semiconductor light-emitting device 310b according to this modification. In Fig. 26, in order to show the interior of the cap unit, the cap unit is shown before being attached to the wiring substrate 320b. Therefore, a second bonding preliminary film 355c arranged along the bonding surface of the cap unit is also shown. In this modification, a plurality of semiconductor light-emitting elements 41 and reflective optical elements 358 are arranged in a matrix of 3 rows and 3 columns.

[0168] The semiconductor light emitting device 310b according to this modification includes a wiring substrate 320b, a plurality of semiconductor light emitting elements 41, a plurality of submounts 45, a cap unit (not shown in FIG. 26), a temperature detection element 60, and connectors 371 and 372.

[0169] The wiring substrate 320b has a metal substrate (not shown in FIG. 26), a first insulating layer 321, first metal layers 331a-331c, second metal layers 332a-332c, a third metal layer 333, a fourth metal layer 334, spacer layers 530a-530i, a plurality of first pad electrodes 331p, a plurality of second pad electrodes 332p, and a second insulating layer 322.

[0170] The wiring board 320b is formed with positioning holes 229a and 229b and through holes 228a to 228d.

[0171] The first insulating layer 321 is disposed on the metal substrate, and has an opening 321a formed therein.

[0172] The first metal layers 331a to 331c are disposed on the first insulating layer 321 and connected to the first pad electrode 331p and the connector 371. The second metal layers 332a to 332c are disposed on the first insulating layer 321 and connected to the second pad electrode 332p and the connector 372.

[0173] The third metal layer 333 is disposed on the first insulating layer 321 and is connected to the temperature sensing element 60 and the connector 371. The fourth metal layer 334 is disposed on the first insulating layer 321 and is connected to the temperature sensing element 60 and the connector 372.

[0174] The second insulating layer 322 is disposed on the first insulating layer 321 and covers at least a portion of each of the first metal layers, each of the second metal layers, and each of the spacer layers.

[0175] The spacer layers 530a to 530i are disposed at positions different from the first metal layers and second metal layers between the bonding surface of the cap unit and the first insulating layer 321. In this modification, too, the spacer layers are disposed along the bonding surface of the cap unit.

[0176] In this modification, the semiconductor light emitting element 41 is mounted on a submount 45. Three light emitting elements 41 are arranged in the same row (i.e., arranged in the left-right direction in FIG. 26). of The semiconductor light emitting elements 41 are electrically connected in series by metal wires W1. The first pad electrodes 331p and the second pad electrodes 332p are arranged in the horizontal direction (the left-right direction in FIG. 26) of the semiconductor light emitting elements 41 arranged in the three rows. That is, a first pad electrode 331p and a second pad electrode 332p are electrically connected in series between the first pad electrode 331p and the second pad electrode 332p. columnA plurality of semiconductor light emitting elements 41 connected to each other are arranged side by side. In this modification, three semiconductor light emitting elements 41 are arranged in the row direction. Three first pad electrodes 331p and three second pad electrodes 332p are arranged in the column direction, corresponding to the three columns of semiconductor light emitting element groups. Each first pad electrode 331p is connected to the semiconductor light emitting element 41 by a metal wire W2. Each second pad electrode 332p is connected to the semiconductor light emitting element 41 by a metal wire W3. The plurality of first pad electrodes 331p and second pad electrodes 332p are connected to two connectors 371 and 372 provided at opposing positions on the wiring substrate 320b by corresponding plurality of first metal layers 331a to 331c and second metal layers 332a to 332c, respectively.

[0177] With the above-described configuration, the optical output of the light emitted from the semiconductor light-emitting device 310b can be increased compared to when a single semiconductor light-emitting element 41 is used. Furthermore, as the optical output increases, the heat generated by the semiconductor light-emitting device 410 also increases. However, the semiconductor light-emitting device 310b according to this modification can efficiently dissipate the heat using a heat sink or the like, thereby suppressing deterioration of each semiconductor light-emitting element. Therefore, a semiconductor light-emitting device 310b with high optical output and high reliability can be realized. Such a semiconductor light-emitting device 310b can be used as a light source for a projector, for example, by using a semiconductor laser element or the like that emits light having a wavelength in the visible light range, such as blue, green, or red, as the semiconductor light-emitting element 41.

[0178] (Fourth embodiment) Next, a semiconductor light emitting device according to embodiment 4 will be described. The semiconductor light emitting device according to this embodiment differs from semiconductor light emitting device 10 according to embodiment 1 in that it includes a plurality of semiconductor light emitting elements. The semiconductor light emitting device according to this embodiment will be described below with reference to FIG. 27, focusing on the differences from semiconductor light emitting device 10 according to embodiment 1.

[0179] Fig. 27 is a schematic top view showing the overall configuration of a semiconductor light emitting device 410 according to this embodiment. In Fig. 27, in order to show the inside of the cap unit 450, a state before the cap unit is attached to the wiring substrate 420 is shown. For this reason, a second bonding preliminary film 455c arranged along the bonding surface of the cap unit is shown.

[0180] A semiconductor light emitting device 410 according to this embodiment includes a wiring substrate 420, a cap unit 450, semiconductor light emitting elements 441a to 441c, a submount 445, a temperature detecting element 60, a shielding member 60s, and a connector .

[0181] The cap unit 450, the temperature detection element 60, and the connector 70 have the same configurations as the cap unit 50, the temperature detection element 60, and the connector 70 according to the first embodiment, respectively. The cap unit 450 has a side wall 451 that is a light-transmitting window. The shielding member 60s has the same configuration as the shielding member 60s according to the third modification of the first embodiment. In this embodiment, the temperature detection element 60 and the shielding member 60s are disposed inside the cap unit 450.

[0182] Similar to the wiring board 20 according to the first embodiment, the wiring board 420 includes a metal substrate 428, a first insulating layer 421, a second insulating layer 422, spacer layers 430a, 430b, 430c, and 430d, a first metal layer 431, a second metal layer 432, a third metal layer 433, a fourth metal layer 434, a first pad electrode 431p, a second pad electrode 432p, and a protective film (not shown in FIG. 27). In FIG. 27, the spacer layers 430a, 430b, 430c, and 430d, the first metal layer 431, the second metal layer 432, the third metal layer 433, and the fourth metal layer 434 are hidden under the second insulating layer 422 and are therefore indicated by dashed lines.

[0183] In this embodiment, wiring board 420 is formed with through holes 428a and 428b and positioning holes 429a and 429b, similar to wiring board 20 according to the first embodiment.

[0184] In the first insulating layer, openings 421a are formed similarly to first insulating layer 21 according to embodiment 1. A protective film made of Ni, Au, or the like is formed in openings 421a, forming mounting surfaces for mounting the semiconductor light emitting elements. In this embodiment, semiconductor light emitting elements 441a to 441c are disposed in the openings via submounts 445.

[0185] The first metal layer 431, the second metal layer 432, the third metal layer 433, and the fourth metal layer 434, the first pad electrode 431p, and the second pad electrode 432p have the same configuration as the first metal layer 431, the second metal layer 432, the third metal layer 433, the fourth metal layer 434, the first pad electrode 31p, and the second pad electrode 32p in embodiment 1, respectively.

[0186] Like the spacer layers according to the first embodiment, the spacer layers 430a, 430b, 430c, and 430d according to the present embodiment are disposed between the bonding surface of the cap unit 450 with the wiring substrate 420 and the first insulating layer of the wiring substrate 420. In the present embodiment, the spacer layers are disposed at positions different from the metal layers on the first insulating layer. This allows the semiconductor light emitting device 410 according to the present embodiment to achieve the same effects as the semiconductor light emitting device 10 according to the first embodiment.

[0187] The submount 445 includes an insulating block, which is a rectangular parallelepiped block made of an insulating material; first electrodes 447a-447c and a second electrode 448, which are metal films arranged on the upper surface of the insulating block; and a metal film (not shown) arranged on the lower surface of the insulating block. The first electrodes 447a-447c and the second electrode 448 are arranged spaced apart from each other and are electrically insulated. The first electrodes 447a-447c and the second electrode 448 are also electrically insulated from the metal film arranged on the lower surface of the insulating block. The first electrodes 447a-447c, the second electrode 448, and the metal film arranged on the lower surface of the insulating block are metal films made of Ni, Cu, Pi, Au, or the like.

[0188] Each of the semiconductor light emitting elements 441a to 441c has the same configuration as the semiconductor light emitting element 41 according to embodiment 1. In this embodiment, the semiconductor light emitting elements 441a to 441c are junction-down mounted on first electrodes 447a to 447c, respectively.

[0189] Furthermore, the first pad electrode 431p and the first electrode 447a are connected by a metal wire W2. The upper surface of the semiconductor light emitting element 441a and the first electrode 447b are connected by a metal wire W1. The upper surface of the semiconductor light emitting element 441b and the first electrode 447c are connected by a metal wire W1. The upper surface of the semiconductor light emitting element 441c and the second electrode 448 are connected by a metal wire W1. The second electrode 448 and the second pad electrode 432p are connected by a metal wire W3. This allows the semiconductor light emitting elements 441a to 441c to be connected in series. Therefore, the same current can be supplied to each semiconductor light emitting element.

[0190] With the above configuration, the optical output of light emitted from semiconductor light emitting device 410 can be increased compared to when a single semiconductor light emitting element 41 is used. As the optical output increases, the heat generated by semiconductor light emitting device 410 also increases, but with semiconductor light emitting device 410 according to this embodiment, the heat can be efficiently dissipated using a heat sink or the like, thereby suppressing deterioration of each semiconductor light emitting element.

[0191] (Variations, etc.) Although the semiconductor light emitting device and the like according to the present disclosure have been described above based on the respective embodiments, the present disclosure is not limited to the above-described respective embodiments.

[0192] For example, although the semiconductor light emitting element is a semiconductor light emitting element in each of the above embodiments, the semiconductor light emitting element is not limited to a semiconductor light emitting element, and may be, for example, a superluminescent diode or a quantum cascade laser.

[0193] In addition, although the above-described embodiments have shown examples in which a metal substrate is used as the first substrate, the first substrate may be an insulating substrate, in which case the wiring substrate does not need to have a first insulating layer.

[0194] Furthermore, in the above-described embodiments, a temperature detection element is used as an example of a functional element, but other functional elements may be used. Examples of other functional elements that may be used include light-receiving elements, switching elements such as transistors, and various passive elements such as capacitors, inductors, and resistors. Furthermore, the shape of the metal layer or pad electrode connected to the functional element can be selected as desired depending on the type of functional element. Furthermore, the semiconductor light-emitting element and the functional element may be electrically connected on a wiring substrate.

[0195] Furthermore, the semiconductor light emitting device according to the second modification of the second embodiment includes the shielding member 60s, but the cap unit 50 may function as the shielding member when the temperature detection element 60 is disposed outside the cap unit 50. That is, by reducing the transmittance of light from the semiconductor light emitting element 41 in the side wall facing the rear end face 41R of the semiconductor light emitting element 41, among the four side walls of the cap unit 50, the cap unit 50 can be made to function as the shielding member.

[0196] In addition, in each of the above embodiments, the semiconductor light emitting element is mounted on the metal substrate via a submount, but it may be mounted directly without a submount, in which case the semiconductor light emitting element may be junction-up mounted on the metal substrate.

[0197] Although the above-described embodiments have shown semiconductor light emitting devices equipped with cap units, semiconductor light emitting devices without cap units can also be realized. Such a semiconductor light emitting device will be described with reference to Fig. 28. Fig. 28 is a schematic perspective view showing the configuration of a semiconductor light emitting device 910 according to a reference example.

[0198] The semiconductor light emitting device 910 includes a wiring substrate 920, a semiconductor light emitting element 41, a submount 45, a temperature detecting element 60, and a connector . This reference example The semiconductor light emitting element 41, the submount 45, the temperature detection element 60, and the connector 70 have the same configurations as the semiconductor light emitting element 41, the submount 45, the temperature detection element 60, and the connector 70 according to the first embodiment.

[0199] The wiring board 920 differs from the wiring board 20 according to the first embodiment in the configuration of the first insulating layer 921, the configurations of the third metal layer 933 and the fourth metal layer 934, and the absence of a spacer layer, but is otherwise identical in configuration. The opening 921a of the first insulating layer 921 extends to the edge of the wiring board 920. That is, the opening 921a has an opening shape that opens on the side of the first insulating layer 921 in the emission direction of the emitted light L1 from the semiconductor light emitting element 41. The third metal layer 933 and the fourth metal layer 934 have the same configurations as the third metal layer 233 and the fourth metal layer 234 according to the second embodiment, respectively. The second insulating layer 922 has the same configuration as the second insulating layer 222 according to the second embodiment.

[0200] A high light output semiconductor light emitting device can be realized even with the semiconductor light emitting device 910 having such a configuration without a cap unit. Furthermore, since the semiconductor light emitting device 910 does not have a cap unit or a spacer layer, it has a simpler configuration than the semiconductor light emitting device 10 according to the first embodiment and offers greater design freedom.

[0201] This disclosure also includes forms obtained by applying various modifications to the above-mentioned embodiments that a person skilled in the art would conceive, and forms realized by arbitrarily combining the components and functions of the above-mentioned embodiments within the scope of the present disclosure. [Industrial Applicability]

[0202] The semiconductor light-emitting device of the present disclosure can be applied, for example, as a high-light-output and highly reliable light source to laser processing machines, vehicle lighting devices such as vehicle headlights, lighting devices, distance measuring devices such as LiDAR devices, light source devices for projectors, medical light source devices, light source devices for inspections, light source devices for sterilization, and the like. [Explanation of symbols]

[0203] 10, 110, 110a, 110b, 210, 310, 310b, 410, 910 Semiconductor light-emitting device 20, 220, 320b, 420, 920 wiring board 20a, 220a top surface 20b Heat dissipation surface 21, 221, 321, 421, 921 First insulating layer 21a, 22a, 22b, 22c, 22d, 221a, 321a, 421a, 921a opening 21M Insulating Substrate 22, 222, 322, 422, 922 Second insulating layer 25, 35, 225, 235 Protective film 26, 42, 55, 62, 226, 255b Joint members 28, 228, 428 Metal substrate 28a, 28b, 228a, 228b, 228c, 228d, 428a, 428b through hole 28c beveled cut surface 29a, 29b, 229a, 229b, 429a, 429b Positioning holes 30a, 30b, 30c, 130a, 130b, 230a, 230b, 230c, 430a, 430b, 430c, 430d, 530a, 530b, 530c, 530d, 530e, 530f, 530g, 530h, 530i spacer layer 30M metal foil 31, 231, 331a, 331b, 331c, 431 1st metal layer 31p, 231p, 331p, 431p First pad electrode 32, 232, 332a, 332b, 332c, 432 2nd metal layer 32p, 232p, 332p, 432p Second pad electrode 33, 233, 333, 433, 933 3rd metal layer 34, 234, 334, 434, 934 4th metal layer 41, 441a, 441b, 441c Semiconductor light emitting element 41e Light-emitting point 41R Rear end surface 45, 445 submount 47, 447a, 447b, 447c 1st electrode 48, 448 2nd electrode 50, 350, 450 cap units 50b Joint surface 51, 52a, 52b, 52c, 451 side wall 51a Inorganic transparent plate 51b, 51c Anti-reflective coating 52, 352 holder 52d, 351 top plate 55v gap 60 Temperature detection element 60s shielding material 70, 270, 271, 371, 372 Connectors 91 Image Observation System 92 Lens Optical Elements 211, 212, 272 cables Terminals 213 and 214 219 Heat Sink 237 First extraction electrode 237a, 238a Electrode through hole 238 Second extraction electrode 255 Bonding layer 255a First bonding preliminary film 255c, 355c, 455c Second bonding preliminary film 358 Reflective Optical Elements 358r reflective surface 359 Bonding pre-film CT cutter L length L1 output light P1, P2 positioning pins S1, S2, Sc1 terminal fixing screws S3, S4 fixing screws S L1 Beam Cross Section T Thickness T1, T2, T3, T4 screw holes TP1, TP5 heat flow W width W1, W2, W3 Metal Wires Wi washer

Claims

1. A wiring board; a semiconductor light-emitting element disposed on an upper surface of the wiring substrate; a cap unit disposed on an upper surface of the wiring substrate and covering the semiconductor light emitting element; The wiring board is a first substrate; a first metal layer and a second metal layer spaced apart from each other on the first substrate; a spacer layer disposed on the first substrate; a bonding surface of the cap unit that is bonded to the wiring substrate intersects with the first metal layer and the second metal layer in a top view of the wiring substrate; the spacer layer is disposed between the bonding surface and the first substrate at a position different from the first metal layer and the second metal layer; The wiring substrate includes at least the first metal layer, the second metal layer, and the spacer layer. A second insulating layer covers the part. Semiconductor light-emitting device.

2. The semiconductor light-emitting element has an optical waveguide extending in a direction parallel to the upper surface of the wiring substrate. The semiconductor light emitting device according to claim 1 .

3. The cap unit has a rectangular top plate and four side walls respectively connected to four sides of the periphery of the top plate, the top plate is a light-transmitting window having an inorganic light-transmitting plate and an anti-reflection film formed on the inorganic light-transmitting plate, The light emitted from the semiconductor light emitting element passes through the light-transmitting window. The semiconductor light emitting device according to claim 1 .

4. A wiring board; a semiconductor light-emitting element disposed on an upper surface of the wiring substrate; a cap unit disposed on an upper surface of the wiring substrate and covering the semiconductor light emitting element; The wiring board is a first substrate; a first metal layer and a second metal layer spaced apart from each other on the first substrate; a spacer layer disposed on the first substrate; a bonding surface of the cap unit that is bonded to the wiring substrate intersects with the first metal layer and the second metal layer in a top view of the wiring substrate; the spacer layer is disposed between the bonding surface and the first substrate at a position different from the first metal layer and the second metal layer; The cap unit has a rectangular top plate and four side walls respectively connected to four sides of the periphery of the top plate, the wiring substrate and the four side walls are bonded to each other on the spacer layer; the top plate is a light-transmitting window having an inorganic light-transmitting plate and an anti-reflection film formed on the inorganic light-transmitting plate, The light emitted from the semiconductor light emitting element passes through the light-transmitting window. Semiconductor light-emitting device.

5. A wiring board; a semiconductor light-emitting element disposed on an upper surface of the wiring substrate; a cap unit disposed on an upper surface of the wiring substrate and covering the semiconductor light emitting element; The wiring board is a first substrate; a first metal layer and a second metal layer spaced apart from each other on the first substrate; a spacer layer disposed on the first substrate; a bonding surface of the cap unit that is bonded to the wiring substrate intersects with the first metal layer and the second metal layer in a top view of the wiring substrate; the spacer layer is disposed between the bonding surface and the first substrate at a position different from the first metal layer and the second metal layer; The cap unit is connected to a rectangular top plate and to four sides of the periphery of the top plate. four side walls; one of the four side walls is a light-transmitting window having an inorganic light-transmitting plate and an anti-reflection film disposed on the inorganic light-transmitting plate; The light emitted from the semiconductor light emitting element passes through the light-transmitting window. Semiconductor light-emitting device.

6. The wiring substrate and the four side walls are bonded on the spacer layer.

6. The semiconductor light emitting device according to claim 3.

7. The top plate is transparent.

7. The semiconductor light emitting device according to claim 5.

8. The distance between the light-transmitting window and the light-emitting surface of the semiconductor light-emitting element is greater than zero and less than the thickness of the light-transmitting window.

8. The semiconductor light emitting device according to claim 5.

9. The thickness of the side walls other than the light-transmitting window among the four side walls is greater than the thickness of the light-transmitting window. The semiconductor light emitting device according to claim 8 .

10. The semiconductor light emitting element has an optical waveguide extending in a direction parallel to the upper surface of the wiring substrate.

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

11. the semiconductor light emitting device includes a submount disposed between the wiring substrate and the semiconductor light emitting element, The light emitting surface of the semiconductor light emitting element protrudes from the end surface of the submount. The semiconductor light emitting device according to claim 10.

12. The wiring substrate has a second insulating layer that covers at least a portion of the first metal layer, the second metal layer, and the spacer layer. The semiconductor light emitting device according to any one of claims 4 to 11.

13. the semiconductor light emitting device includes a reflective optical element; The light emitted from the semiconductor light emitting element is reflected by the reflecting optical element, Propagating in a direction perpendicular to the top surface of the wiring board 5. The semiconductor light emitting device according to claim 3.

14. the wiring substrate further includes a first insulating layer disposed on an upper surface of the first substrate; The first metal layer, the second metal layer, and the spacer layer are disposed on the first insulating layer. The semiconductor light emitting device according to any one of claims 1 to 13.

15. The first substrate is a metal substrate. The semiconductor light emitting device according to claim 14.

16. An opening is formed in the first insulating layer, The semiconductor light emitting element is disposed within the opening. The semiconductor light emitting device according to claim 14 or 15.

17. The spacer layer is disposed along the joining surface. The semiconductor light emitting device according to any one of claims 1 to 16.

18. The spacer layer is made of a metal material. The semiconductor light emitting device according to any one of claims 1 to 17.

19. The spacer layer is made of the same material as the first metal layer or the second metal layer and is electrically connected to the first metal layer or the second metal layer. The semiconductor light emitting device according to any one of claims 1 to 18.

20. a functional element disposed on the wiring substrate; The semiconductor light emitting device according to any one of claims 1 to 19.

21. The functional element is covered by the cap unit.

21. The semiconductor light emitting device according to claim 20.

22. The functional element is a temperature sensing element.

22. The semiconductor light emitting device according to claim 20 or 21.

23. a shielding member disposed between the temperature detection element and the semiconductor light emitting element; 23. The semiconductor light emitting device according to claim 22.

24. The first substrate has an obliquely cut surface at an end thereof. The semiconductor light emitting device according to any one of claims 1 to 23.

25. The lower surface of the first substrate is a heat dissipation surface. The semiconductor light emitting device according to any one of claims 1 to 24.

26. A semiconductor light emitting device according to any one of claims 1 to 25; a heat sink on which the semiconductor light emitting device is disposed; a fixing screw for fixing the semiconductor light emitting device to the heat sink, The wiring board has a through hole formed therein, The fixing screw passes through the through hole and is fixed to the heat sink. Light source device.

27. a cable having a terminal; and a terminal fixing screw. the wiring substrate has an extraction electrode electrically connected to the first metal layer, an electrode through-hole is formed in the center of the extraction electrode; The terminal fixing screw passes through the electrode through-hole, the terminal is disposed between the terminal fixing screw and the extraction electrode, The extraction electrode and the terminal are electrically connected.

27. The light source device according to claim 26.

Images