SEMICONDUCTOR LIGHT-EMITTING DEVICE AND LIGHT SOURCE DEVICE

A semiconductor light-emitting device is provided which includes: a wiring substrate; a semiconductor light-emitting element disposed above an upper surface of the wiring substrate; and a cap unit which covers the semiconductor light-emitting element. The wiring substrate includes: a first substrate; a first metal layer and a second metal layer that are spaced apart from each other above the first substrate; and a spacer layer disposed above the first substrate. The cap unit includes a bonding surface which is bonded to the wiring substrate. The bonding surface intersects the first metal layer and the second metal layer in a top view of the wiring substrate, and the spacer layer is disposed between the bonding surface and the first substrate, at a position different from positions of the first metal layer and the second metal layer.

FIELD

The present disclosure relates to a semiconductor light-emitting device and a light source device.

BACKGROUND

A semiconductor light-emitting device has been proposed in which a semiconductor light-emitting element such as a semiconductor laser element is mounted above a substrate and a cap covers the semiconductor light-emitting element (see Patent Literature (PTL) 1 and 2, etc., for example).

A configuration in which a semiconductor laser element is mounted above a substrate via a submount, and a cap that covers the semiconductor laser element is disposed above the substrate is proposed in PTL 1 and 2. A transparent plate for extracting out laser light is provided on a side surface of the cap.

According to PTL 1 and 2, the heat dissipation property of the semiconductor laser element is enhanced by the submount and the substrate, and the cap hermetically seals the semiconductor laser element, thereby trying to enhance the reliability of the semiconductor laser element.

CITATION LIST

Patent Literature

SUMMARY

Technical Problem

In such a configuration as described in PTL 1 and 2, the increase in optical output of the semiconductor light-emitting element disposed inside the cap requires a large amount of current to be supplied to the semiconductor light-emitting element. For this reason, it is necessary to use, as wiring for supplying current to the semiconductor light-emitting element, a wiring having a large cross-sectional area which is suitable to supply a large amount of current, i.e., wiring with low resistance. When such a wiring having a large cross-sectional area is disposed above the substrate, the wiring having a large cross-sectional area is placed between the cap and the substrate, and thus a gap is created between the cap and the substrate. This makes it difficult to seal the gap between the cap and the substrate. In order to avoid such a problem, the wiring could be disposed inside the substrate, but this makes the configuration of the substrate complicated and increases costs.

The present disclosure solves such problems and provides a semiconductor light-emitting device, etc. having a simplified configuration and capable of achieving an increase in optical output and enhanced reliability of the semiconductor light-emitting element.

Solution to Problem

In order to solve the above-described problems, a semiconductor light-emitting device according to one aspect of the present disclosure includes a wiring substrate; a semiconductor light-emitting element disposed above an upper surface of the wiring substrate; and a cap unit which is disposed above the upper surface of the wiring substrate and covers the semiconductor light-emitting element. In the semiconductor light-emitting device, the wiring substrate includes: a first substrate; a first metal layer and a second metal layer that are spaced apart from each other above the first substrate; and a spacer layer disposed above the first substrate, the cap unit includes a bonding surface which is bonded to the wiring substrate, the bonding surface intersecting the first metal layer and the second metal layer in a top view of the wiring substrate, and the spacer layer is disposed between the bonding surface and the first substrate, at a position different from positions of the first metal layer and the second metal layer.

In addition, in one aspect of the semiconductor light-emitting device according to the present disclosure, the wiring substrate may further include a first insulating layer disposed above the upper surface of the first substrate, and the first metal layer, the second metal layer, and the spacer layer may be disposed above the first insulating layer.

In addition, in one aspect of the semiconductor light-emitting device according to the present disclosure, the first substrate may be a metal substrate.

In addition, in one aspect of the semiconductor light-emitting device according to the present disclosure, the metal substrate may comprise a metal flat plate.

In addition, in one aspect of the semiconductor light-emitting device according to the present disclosure, the first insulating layer may include an opening, and the semiconductor light-emitting element may be disposed in the opening.

In addition, in one aspect of the semiconductor light-emitting device according to the present disclosure, the spacer layer may be disposed along the bonding surface.

In addition, in one aspect of the semiconductor light-emitting device according to the present disclosure, the wiring substrate may include a second insulating layer that covers at least one of a portion of the first metal layer, a portion of the second metal layer, or a portion of the spacer layer.

In addition, in one aspect of the semiconductor light-emitting device according to the present disclosure, the spacer layer may comprise a metal material.

In addition, in one aspect of the semiconductor light-emitting device according to the present disclosure, the spacer layer may comprise a material that one of the first metal layer or the second metal layer includes, and may be electrically connected to the one of the first metal layer or the second metal layer.

In addition, in one aspect of the semiconductor light-emitting device according to the present disclosure, the cap unit may include a top plate which is rectangular, and four side walls each connected to a corresponding one of four sides at a peripheral edge of the top plate, one of the four side walls may be a light-transmissive window including an inorganic light-transmissive plate and an antireflection film disposed on the inorganic light-transmissive plate, and emitted light from the semiconductor light-emitting element may pass through the light-transmissive window.

In addition, in one aspect of the semiconductor light-emitting device according to the present disclosure, the top plate may be transparent.

In addition, in one aspect of the semiconductor light-emitting device according to the present disclosure, a gap between the light-transmissive window and an emission surface of the semiconductor light-emitting element may be greater than zero and less than a thickness of the light-transmissive window.

In addition, in one aspect of the semiconductor light-emitting device according to the present disclosure, among the four side walls, side walls other than the light-transmissive window may each have a thickness greater than the thickness of the light-transmissive window.

In addition, in one aspect of the semiconductor light-emitting device according to the present disclosure, the cap unit may include a top plate which is rectangular, and four side walls each connected to a corresponding one of four sides at a peripheral edge of the top plate, the top plate may be a light-transmissive window including an inorganic light-transmissive plate and an antireflection film disposed on the inorganic light-transmissive plate, and emitted light from the semiconductor light-emitting element may pass through the light-transmissive window.

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

In addition, in one aspect of the semiconductor light-emitting device according to the present disclosure, the semiconductor light-emitting device may include a functional element disposed above the wiring substrate.

In addition, in one aspect of the semiconductor light-emitting device according to the present disclosure, the functional element may be covered by the cap unit.

In addition, in one aspect of the semiconductor light-emitting device according to the present disclosure, the functional element may be a temperature sensing element.

In addition, in one aspect of the semiconductor light-emitting device according to the present disclosure, the temperature sensing element may be disposed at a position at which the temperature sensing element does not intersect an optical axis of the semiconductor light-emitting element.

In addition, in one aspect of the semiconductor light-emitting device according to the present disclosure, the semiconductor light-emitting device may further include a shielding component disposed between the temperature sensing element and the semiconductor light-emitting element.

In addition, in one aspect of the semiconductor light-emitting device according to the present disclosure, the first substrate may include a slanted cut surface at an end portion.

In addition, in order to solve the above-described problems, a light source device according to one aspect of the present disclosure includes the above-described semiconductor light-emitting device, a heat sink on which the semiconductor light-emitting device is disposed, and a fixing screw that fixes the semiconductor light-emitting device to the heat sink. In the light source device, the wiring substrate includes a through-hole, and the fixing screw penetrates through the through-hole and is fixed to the heat sink.

In addition, the light source device according to one aspect of the present disclosure may include a cable including a terminal, and a terminal fixing screw. In the light source device, the wiring substrate may include an extraction electrode electrically connected to the first metal layer, the extraction electrode may include an electrode through-hole at a center portion, the terminal fixing screw may penetrate through the electrode through-hole, the terminal may be disposed between the terminal fixing screw and the extraction electrode, and the extraction electrode and the terminal may be electrically connected to each other.

Advantageous Effects

According to the present disclosure, it is possible to provide a semiconductor light-emitting device, etc. having a simplified configuration and capable of achieving an increase in optical output and enhanced reliability of the semiconductor light-emitting element.

DESCRIPTION OF EMBODIMENTS

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. It should be noted that each of the embodiments described below shows a specific example of the present disclosure. Therefore, numerical values, shapes, materials, structural components, the arrangement and connection of the structural components, etc. indicated in the following embodiments are mere examples, and are not intended to limit the scope of the present disclosure.

In addition, each of the diagrams is a schematic diagram and thus is not necessarily strictly illustrated. Therefore, the scale sizes and the like are not necessarily exactly represented in each of the diagrams. In each of the diagrams, substantially the same structural components are assigned with the same reference signs, and redundant descriptions will be omitted or simplified.

Moreover, in the present specification, the terms “above” and “below” do not refer to the vertically upward direction and vertically downward direction in terms of absolute spatial recognition, but are used as terms defined by relative positional relationships based on the layering order in a layered configuration. Furthermore, the terms “above” and “below” are applied not only when two structural components are disposed with a gap therebetween or when a separate structural component is interposed between two structural components, but also when two structural components are disposed in contact with each other.

A semiconductor light-emitting device according to Embodiment 1 will be described below.

1-1. Overall Configuration

First, the overall configuration of the semiconductor light-emitting device according to the present embodiment will be described with reference toFIG.1AtoFIG.4.FIG.1AandFIG.1Bare a perspective view and a top view, respectively, each of which illustrates the overall configuration of semiconductor light-emitting device10according to the present embodiment.FIG.2is a perspective view schematically illustrating the configuration of the inside of cap unit50of semiconductor light-emitting device10according to the present embodiment. InFIG.2, semiconductor light-emitting device10with a portion of cap unit50removed is illustrated.FIG.3Ais an exploded perspective view schematically illustrating the overall configuration of semiconductor light-emitting device10according to the present embodiment.FIG.3Bis an equivalent circuit illustrating the circuit configuration of semiconductor light-emitting device10according to the present embodiment.FIG.4is cross-sectional view schematically illustrating the overall configuration of semiconductor light-emitting device10according to the present embodiment.FIG.4illustrates semiconductor light-emitting device10in cross section taken along line IV-IV indicated inFIG.1B.

Semiconductor light-emitting device10according to the present embodiment is a device that emits light, and includes wiring substrate20, semiconductor light-emitting element41, and cap unit50, as illustrated inFIG.3A. According to the present embodiment, semiconductor light-emitting device10further includes submount45, temperature sensing element60, connector70, and bonding materials26,42,55and62, as illustrated inFIG.4. The following describes each of the structural components of semiconductor light-emitting device10.

Wiring substrate20is a plate-like component which serves as a base of semiconductor light-emitting device10, and is provided with wiring. Upper surface20aof wiring substrate20is a component mounting surface. A lower surface facing away from upper surface20a(i.e., the surface located on the back side of upper surface20a) is heat-dissipating surface20b. As illustrated inFIG.4, wiring substrate20includes metal substrate28, first insulating layer21, second insulating layer22, spacer layers30aand30b, third metal layer33, fourth metal layer34, and protection films25and35. In addition, wiring substrate20further includes first metal layer31, second metal layer32, first pad electrode31p, and second pad electrode32p, as illustrated inFIG.2andFIG.3A. It should be noted that, inFIG.1A,FIG.1B,FIG.2, andFIG.3A, first metal layer31, second metal layer32, third metal layer33, fourth metal layer34, and each of the spacer layers are covered by second insulating layer22, and thus do not appear on the surface. However, a portion of second insulating layer22located above each of the above-described layers protrudes upward, and thus the position of an end edge of each of the above-described layers is indicated as the position of a step in second insulating layer22. In addition, since each of the above-described layers is covered by second insulating layer22, dashed pull-out lines are added to reference numerals indicating these metal layers. The same holds true for each of the metal layers and each of the spacer layers illustrated in the top views and perspective views that will be described below.

According to the present embodiment, wiring substrate20includes through-holes28aand28band positioning holes29aand29b. Through-holes28aand28bare holes for inserting a fixing component such as a screw when fixing wiring substrate20to closely adhere to a heat sink or the like. Through-holes28aand28bare located on one side and the other side of wiring substrate20, respectively, relative to the region in which semiconductor light-emitting element41is disposed. It should be noted that, in the following description, the upward direction and the downward direction ofFIG.1Bare referred to as one and the other, respectively. In other words, semiconductor light-emitting element41is disposed between through-hole28aand through-hole28b.

Positioning holes29aand29bare holes for positioning wiring substrate20to a heat sink or the like when fixing wiring substrate20to the heat sink or the like. For example, positioning pins provided on a heat sink or the like at the positions where positioning holes29aand29bare to be arranged are fitted into positioning holes29aand29b, respectively. This allows positioning wiring substrate20at a predetermined position of a heat sink or the like. According to the present embodiment, positioning hole29ais a first positioning hole and has a circular shape in a top view of wiring substrate20. Positioning hole29bis a second positioning hole and has a long hole shape (i.e., an ellipse shape) in the top view of wiring substrate20.

Metal substrate28is an example of a first substrate that wiring substrate20includes. Metal substrate28comprises a flat plate of metal such as oxygen-free copper or copper alloy. Here, the flat plate is a plate which does not have a patterned unevenness shape with a depth or height greater than the surface roughness on the surface other than the peripheral portion. Since the upper surface of metal substrate28is flat, first insulating layer21which is flat can be formed above metal substrate28. This facilitates the formation of a thick metal layer above first insulating layer21. Metal substrate28is, for example, a flat plate that comprises oxygen-free copper having a thickness of approximately greater than or equal to 0.5 mm and less than or equal to 3 mm. The shape of metal substrate28(i.e., shape in top view) is, for example, rectangular, and the length of one side of metal substrate28is, for example, approximately greater than or equal to 5 mm and less than or equal to 30 mm. According to the present embodiment, slanted cut surface28cwhich is a slanted surface that is slanted with respect to the main surface of metal substrate28is formed at the edge of metal substrate28. First insulating layer21is formed above the upper surface of metal substrate28, and no insulating layer is formed above the lower surface of metal substrate28(i.e., the surface located on the back side of the upper surface). Accordingly, the entire area of the lower surface of metal substrate28can be used as heat-dissipating surface20bof wiring substrate20, and thus it is possible to dissipate heat over a large area. As a result, it is possible to use semiconductor light-emitting element41which is high in optical output and large in the amount of heat generation.

First insulating layer21is an insulating layer that is disposed above the upper surface of metal substrate28, as illustrated inFIG.4. First insulating layer21comprises an insulating material such as epoxy glass or ceramic, for example, having a thickness approximately greater than or equal to 0.05 mm and less than or equal to 0.3 mm.

First insulating layer21includes opening21aas illustrated inFIG.2,FIG.3A, andFIG.4. According to the present embodiment, a portion of first insulating layer21is removed to form opening21ahaving a rectangular shape. Opening21ais located to be closer to the edge than the center of metal substrate28is in a top view. In the region corresponding to opening21ain metal substrate28, protection film25that comprises Ni, Au, or the like is formed as illustrated inFIG.4, to form a mounting surface for mounting semiconductor light-emitting element41. According to the present embodiment, semiconductor light-emitting element41is disposed in opening21avia submount45.

First metal layer31, second metal layer32, third metal layer33, and fourth metal layer34are metal layers that are spaced apart from each other above the first substrate, and are disposed above first insulating layer21according to the presented embodiment. First metal layer31and second metal layer32are wiring for supplying power to semiconductor light-emitting element41. Third metal layer33and fourth metal layer34are wiring connected to temperature sensing element60. Each of the metal layers forms protrusion above first insulating layer21. First metal layer31, second metal layer32, third metal layer33, and fourth metal layer34are metal layers comprising copper, for example, having a thickness approximately greater than or equal to 0.02 mm and less than or equal to 0.15 mm.

Spacer layers30aand30bare layers disposed at positions different from the positions of first metal layer31and second metal layer and32above the first substrate, and disposed above first insulating layer21according to the present embodiment. Spacer layers30aand30bare disposed between first insulating layer21and bonding surface50bof cap unit50with wiring substrate20as illustrated inFIG.4. Spacer layers30aand30beach form a protrusion above first insulating layer21in the same manner as each of the metal layers.

According to the present embodiment, spacer layers30aand30bare disposed only between bonding surface50band the first substrate above the first substrate. As illustrated inFIG.5, bonding surface50bhas a loop shape surrounding semiconductor light-emitting element41in a top view of wiring substrate20. More specifically, bonding surface50bhas a rectangular loop shape. Spacer layers30aand30bare disposed along bonding surface50band surround semiconductor light-emitting element41in the top view of wiring substrate20. It should be noted that the meaning of the description that a certain component surrounds semiconductor light-emitting element41includes not only the state in which the certain component is continuously disposed in the entire area surrounding semiconductor light emitting element41, but also the state in which the certain component is disposed in a large portion of the area surrounding semiconductor light-emitting element41. For example, the state in which a certain component surrounds semiconductor light-emitting element41is defined as a state in which the certain component is disposed in at least 80% of the area surrounding semiconductor light-emitting element41.

According to the present embodiment, spacer layer30ais disposed linearly along bonding surface50bthat has a loop shape in the top view of wiring substrate20. Spacer layer30bis disposed in a C-shape along bonding surface50bthat has a loop shape in the top view of the wiring substrate20.

The materials that spacer layers30aand30bcomprise are not particularly limited. According to the present embodiment, spacer layers30aand30bcomprise a metal material. Spacer layers30aand30bare metal layers that comprise copper having a thickness approximately greater than or equal to 0.02 mm and less than or equal to 0.15 mm, as with first metal layer31, for example.

Second insulating layer22is an insulating layer disposed above first insulating layer21. Second insulating layer22covers at least a portion of first metal layer31, second metal layer32, third metal layer33, fourth metal layer34, and spacer layers30aand30b, and also has a function of protecting each of the layers. Second insulating layer22is an insulating layer that comprises, for example, resin such as polyimide, epoxy, or the like having a thickness approximately greater than or equal to 0.05 mm and less than or equal to 0.2 mm.

Protection film25is a metal film disposed, for example, at a position at which submount45, etc. are bonded in wiring substrate20. According to the present embodiment, protection film25is disposed in a region of metal substrate28corresponding to opening21aof first insulating layer21. Protection film35is a metal film disposed above a surface where a metal layer such as first metal layer31is exposed from second insulating layer22. Protection film35is disposed above a portion of the upper surface of first metal layer31, second metal layer32, third metal layer33, and fourth metal layer34, etc. Protection films25and35also serve as anti-corrosion films that protect the exposed surfaces or the like of metal substrate28, first metal layer31, etc., from oxidation and the like. Protection films25and35comprise Ni, Au, or the like, for example.

First pad electrode31pand second pad electrode32pare pad-shaped electrodes disposed above the portions of first metal layer31and second metal layer32, respectively, which are adjacent to semiconductor light-emitting element41. As illustrated inFIG.2andFIG.3A, metal wires W2and W3are bonded to first pad electrode31pand second pad electrode32p, respectively. According to the present embodiment, first pad electrode31pand second pad electrode32pare also part of protection film35and comprise, for example, Ni, Au, or the like.

Semiconductor light-emitting element41is a light-emitting element disposed above upper surface20aof wiring substrate20. Semiconductor light-emitting element41is disposed in opening21aof first insulating layer21. Semiconductor light-emitting element41is a light-emitting element including a compound semiconductor such as gallium nitride or gallium arsenide, for example. According to the present embodiment, semiconductor light-emitting element41is a semiconductor laser element including an optical waveguide that extends in a direction parallel to the main surface of metal substrate28.

As illustrated inFIG.4, semiconductor light-emitting element41is mounted above submount45. Semiconductor light-emitting element41includes a substrate and a semiconductor layered structure that is layered above the substrate. The optical waveguide is formed in the semiconductor layered structure. According to the present embodiment, the semiconductor layered structure of semiconductor light-emitting element41is located to face submount45. In other words, semiconductor light-emitting element41is junction-down mounted to submount45. An electrode (not illustrated) is formed on each of the upper surface (i.e., the surface on the upper side of semiconductor light-emitting element41inFIG.4) and the lower surface (i.e., the surface on the lower side of semiconductor light-emitting element41inFIG.4). The lower surface of semiconductor light-emitting element41faces the upper surface of submount45. As illustrated inFIG.5, the electrode formed on the lower surface, which faces submount45, of semiconductor light-emitting element41is electrically connected to first electrode47formed on the upper surface of submount45. More specifically, the electrode formed on the lower surface of semiconductor light-emitting element41is electrically connected to first electrode47formed on the upper surface of submount45via bonding material42(seeFIG.4) that comprises AuSn solder or the like. The electrode formed on the upper surface of semiconductor light-emitting element41is electrically connected to second electrode48formed on the upper surface of submount45via metal wire W1. First electrode47and second electrode48that are formed on the upper surface of submount45are electrically connected to first pad electrode31pand second pad electrode32p, respectively, via metal wires W2and W3. With the above-described configuration, it is possible to supply current to semiconductor light-emitting element41using first metal layer31and second metal layer32which are connected to first pad electrode31pand second pad electrode32p, respectively.

As illustrated inFIG.4, semiconductor light-emitting element41includes light-emitting point41ewhere emitted light L1is emitted. According to the present embodiment, emitted light L1is laser light. Emitted light L1is laser light having a peak wavelength within a range of from, for example, at least 270 nm to at most 600 nm when semiconductor light-emitting element41includes a gallium nitride-based compound semiconductor, and having a peak wavelength within a range of from, for example, at least 600 nm to at most 10.4 μm when semiconductor light-emitting element41includes a gallium indium phosphide-based compound semiconductor or a gallium arsine-based compound semiconductor. Light-emitting point41eis an end portion, which is located on the left side ofFIG.4, of the optical waveguide included in semiconductor light-emitting element41. Semiconductor light-emitting element41is disposed such that the emission surface which is an end surface on which light-emitting point41eis located protrudes from an end surface of submount45(the left side end surface of submount45illustrated inFIG.4). With this configuration, it is possible to inhibit emitted light L1that has been emitted from light-emitting point41efrom being blocked by submount45.

Semiconductor light-emitting element41has, for example, a rectangular parallelepiped shape with a width approximately greater than or equal to 0.2 mm and less than or equal to 2 mm, a length approximately greater than or equal to 1 mm and less than or equal to 9 mm, and a thickness approximately greater than or equal to 0.08 mm and less than or equal to 0.2 mm.

Submount45is a component disposed between wiring substrate20and semiconductor light-emitting element41. Submount45is mounted above upper surface20aof wiring substrate20. More specifically, as illustrated inFIG.4, submount45is disposed inside opening21aof first insulating layer21, and mounted above metal substrate28via bonding material26and protection film25. Bonding material26comprises, for example, AuSn solder, or the like. Semiconductor light-emitting element41is mounted above the upper surface of submount45. According to the present embodiment, submount45includes an insulating block that is a rectangular parallelepiped block comprising an insulating material, first electrode47and second electrode48each of which is a metal film disposed on the upper surface of the insulating block, and a metal film (not illustrated) disposed on the lower surface of the insulating block. The insulating block comprises an insulating material which is high in thermal conductivity, such as AlN, SiC, diamond, etc. The insulating block has, for example, a rectangular parallelepiped shape with a width approximately greater than or equal to 1 mm and less than or equal to 5 mm, a length approximately greater than or equal to 2 mm and less than or equal to 10 mm, and a thickness approximately greater than or equal to 0.2 mm and less than or equal to 4 mm. First electrode47and second electrode48are spaced apart from each other and electrically insulated. In addition, first electrode47and second electrode48are electrically insulated from the metal film disposed on the lower surface of the insulating block. The metal films disposed on the lower surfaces of first electrode47, second electrode48, and insulating block are metal films that comprise Ni, Cu, Ti, Pt, Au, or the like.

In semiconductor light-emitting device10according to the present embodiment, semiconductor light-emitting element41is mounted above metal substrate28via submount45as described above. With such a configuration as described above, it is possible to efficiently dissipate the heat generated in semiconductor light-emitting element41through submount45to metal substrate28, as indicated by the arrows inFIG.4. The lower surface of metal substrate28is, for example, adhered closely to a heat sink which is not illustrated. With this configuration, it is possible to efficiently conduct the heat generated in semiconductor light-emitting element41from metal substrate28to the heat sink. In addition, since metal substrate28according to the present embodiment is a flat plate, it is easy to manufacture and it is also possible to reduce the cost. Accordingly, it is possible to implement semiconductor light-emitting device10that has a simplified configuration and is manufacturable at low cost.

1-1-4. Cap Unit

Cap unit50is a cover component that is disposed above upper surface20aof wiring substrate20and covers semiconductor light-emitting element41as illustrated inFIG.1A,FIG.1B,FIG.2, andFIG.4. Cap unit50includes bonding surface50bthat faces wiring substrate20as illustrated inFIG.4. Bonding surface50bhas a loop shape, and bonding surface50band upper surface20aof wiring substrate20are bonded by bonding material55comprising an epoxy adhesive, a silicon adhesive, AuSn solder, or the like. In this manner, it is possible to seal the gap between cap unit50and wiring substrate20. According to the present embodiment, as illustrated inFIG.2, cap unit50covers opening21aof first insulating layer21, semiconductor light-emitting element41and submount45disposed in opening21a, first pad electrode31pand second pad electrode32p, and a portion of each of first metal layer31and second metal layer32. Cap unit50includes top plate52dhaving a rectangular shape (seeFIG.4) and four side walls51,52a,52b, and52ceach connected to a corresponding one of the four sides of the peripheral edge of top plate52d(seeFIG.2). According to the present embodiment, side wall51among the four side walls51,52a,52b, and52cis a light-transmissive window, and includes inorganic light-transmissive plate51aand antireflection films51band51cprovided to inorganic light-transmissive plate51a. According to the present embodiment, side wall51includes antireflection films51band51cdisposed on the respective main surfaces of inorganic light-transmissive plate51a. Antireflection film51bis disposed on one of the main surfaces of inorganic light-transmissive plate51athat faces semiconductor light-emitting element41, and antireflection film51cis disposed on the other of the main surfaces located on the back side of the one of the main surfaces. The three side walls52a,52b, and52cand top plate52dare integrally formed to be holder52. Side wall51is disposed at a location facing light-emitting point41eof semiconductor light-emitting element41. With this configuration, emitted light L1from semiconductor light-emitting element41passes through side wall51that is the light-transmissive window.

Holder52comprises glass, for example. Holder52is manufactured by, for example, forming a recess in a glass block having a rectangular parallelepiped shape, by sandblasting or the like, and dividing it.

Side wall51which is a light-transmissive window and holder52are bonded by optical contact or laser bonding to form a cap unit having a box shape.

As a result of cap unit50having the configuration described above, emitted light L1from the semiconductor light-emitting element can be easily extracted from side wall51of cap unit50to the outside.

Thickness Dg of side wall51which is a light-transmissive window illustrated inFIG.4is approximately greater than or equal to 0.01 mm and less than or equal to 0.2 mm. In addition, gap Dgap between side wall51which is a light-transmissive window and the emission surface of semiconductor light-emitting element41(i.e., the end surface including light-emitting point41e) is greater than zero and less than thickness Dg of side wall51. With this configuration, it is possible to reduce the distance (Dg+Dgap) from light-emitting point41eof semiconductor light-emitting element41to the outside of cap unit50. As a result, it is possible to reduce beam cross-sectional area SL1of emitted light L1at the outer surface of cap unit50. For example, when emitted light L1is incident on an optical element such as a lens located outside cap unit50, it is possible to reduce the dimensions of the optical element by reducing beam cross-sectional area SL1of emitted light L1, allowing the optical element to easily couple emitted light L1.

The thickness of each of side walls52a,52b, and52cis greater than the thickness of side wall51which is the light-transmissive window. With this configuration, it is possible to increase the structural strength of the holder and cap unit50while reducing the distance (Dg+Dgap) from light-emitting point41eof semiconductor light-emitting element41to the outside of cap unit50.

1-1-5. Functional Element

Semiconductor light-emitting device10may include a functional element other than semiconductor light-emitting element41. According to the present embodiment, semiconductor light-emitting device10includes temperature sensing element60as one example of the functional element. The following describes temperature sensing element60that is one example of the functional element. Temperature sensing element60is a temperature sensor that is disposed above wiring substrate20. As illustrated inFIG.4, temperature sensing element60is electrically connected to third metal layer33and fourth metal layer34via bonding material62and protection film35. Protection film35is also a pad electrode disposed above third metal layer33and fourth metal layer34. Temperature sensing element60is mounted on the surface of wiring substrate20by means of bonding material62which is, for example, SnAgCu cream solder or the like. The temperature of wiring substrate20can be sensed by temperature sensing element60. It is possible to estimate the temperature of semiconductor light-emitting element41mounted above wiring substrate20via submount45, by sensing the temperature of wiring substrate20. Accordingly, it is possible to estimate the temperature of semiconductor light-emitting element41by temperature sensing element60and use the temperature for controlling semiconductor light-emitting element41. For example, when temperature sensing element60has detected that the temperature of semiconductor light-emitting element41is higher than a predetermined threshold, it is possible to reduce or stop the current supplied to semiconductor light-emitting element41. As temperature sensing element60, for example, a thermistor cab be used. In this case, the resistance value of temperature sensing element60is detected by applying a predetermined voltage to temperature sensing element60and detecting the current flowing through temperature sensing element60. The temperature of wiring substrate20can be detected from the correlation between the resistance value and the temperature. A voltage is applied to temperature sensing element60via third metal layer33and fourth metal layer34. According to the present embodiment, temperature sensing element60is disposed outside cap unit50. With this configuration, it is possible to reduce the size of cap unit50. As a result, it is possible to easily seal the gap between cap unit50and wiring substrate20.

Connector70is a connecting component including terminals each of which is connected to a corresponding one of first metal layer31and second metal layer32. Connector70connects wiring substrate20to external electric circuit (not illustrated). According to the present embodiment, connector70is a receptacle further including terminals each of which is connected to a corresponding one of third metal layer33and fourth metal layer34, as illustrated inFIG.3B, etc. Pad electrodes31q,32q,33q, and34qeach comprising protection film35are formed on first metal layer31, second metal layer32, third metal layer33, and fourth metal layer34, respectively, at end portions on the side that is away from a portion where semiconductor light-emitting element41is disposed, and are connected to connector70. Connector70is mounted above the surface of wiring substrate20by means of bonding material (not illustrated) such as SnAgCu cream solder or the like, and connected to pad electrodes31q,32q,33q, and34q.

1-2. Functions and Advantageous Effects

Next, the functions and advantageous effects of semiconductor light-emitting device10according to the present embodiment will be described with reference to the above-describedFIG.4andFIG.5toFIG.6B.FIG.5is a top view schematically illustrating the positional relationship between (i) bonding surface50bof cap unit50and (ii) semiconductor light-emitting element41, each of the metal layers, and each of the spacer layers of semiconductor light-emitting device10according to the present embodiment.FIG.5illustrates the configuration of semiconductor light-emitting element41and the surroundings of semiconductor light-emitting device10in a state in which cap unit50and second insulating layer22are removed. In addition, inFIG.5, the position of the end edge of bonding surface50bof cap unit50is indicated by the dashed lines.FIG.6AandFIG.6Bare cross-sectional views schematically illustrating the bonding states between the respective wiring substrates and cap unit50according to a comparison example and the present embodiment.FIG.6Billustrates wiring substrate20, etc. at the cross-section surface of line VI-VI ofFIG.5.FIG.6Aillustrates a cross-section of a wiring substrate and cap unit50of the comparison example at the same position asFIG.6B. Cross-sectional view (a) of each ofFIG.6AandFIG.6Bindicates the cross-sectional view before cap unit50and the wiring substrates are bonded, and cross-sectional view (b) of each ofFIG.6AandFIG.6Bindicates the cross-sectional view after they are bonded.

As illustrated inFIG.5, first pad electrode31p, second pad electrode32p, first metal layer31, and second metal layer32extend in the optical axis direction of semiconductor light-emitting element41(i.e., the direction in which the optical waveguide extends, or stated further differently, the direction of resonance). First pad electrode31pand first metal layer31are arranged in the optical axis direction and connected to each other. Second pad electrode32pand second metal layer32are arranged in the optical axis direction and connected to each other. First pad electrode31pand second pad electrode32pare arranged in a lateral direction (i.e., the vertical direction ofFIG.5; that is, the direction perpendicular to the optical axis direction and parallel to the main surface of wiring substrate20), and semiconductor light-emitting element41(and opening21a) is disposed between first pad electrode31pand second pad electrode32p. In addition, first metal layer31and second metal layer32are arranged in the lateral direction, and semiconductor light-emitting element41(and opening21a) is disposed between first metal layer31and second metal layer32.

First metal layer31and second metal layer32extend from the inside of cap unit50toward the rearward of semiconductor light-emitting element41(i.e., in the direction opposite to the direction of propagation of emitted light L1) to the outside of cap unit50. Accordingly, bonding surface50bof cap unit50which is bonded to wiring substrate20intersects first metal layer31and second metal layer32in the top view of wiring substrate20. Hereinafter, the side toward which emitted light L1propagates with respect to semiconductor light-emitting element41is also referred to as forward, and the opposite direction of forward is also referred to as rearward. It should be noted that the portion of first metal layer31where first pad electrode31pand pad electrode31qare not provided is covered by second insulating layer22. The portion of second metal layer32where second pad electrode32pand pad electrode32qare not provided is covered by second insulating layer22.

In addition, as illustrated inFIG.4andFIG.5, spacer layers30aand30bare disposed between bonding surface50band first insulating layer21. Spacer layer30ais disposed at a position rearward from rear end surface41R of semiconductor light-emitting element41on the side opposite to emission surface41F including light-emitting point41ein the optical axis direction. Spacer layer30aextends in the lateral direction between first metal layer31and second metal layer32. Spacer layer30bis composed of five portions.

The first portion of spacer layer30bis disposed at a position rearward from rear end surface41R in the optical axis direction. The first portion of spacer layer30bis disposed further from semiconductor light-emitting element41than first metal layer31is in the lateral direction. In other words, first metal layer31is disposed between the first portion of spacer layer30band semiconductor light-emitting element41in the lateral direction. In addition, first metal layer31is disposed between the first portion of spacer layer30band spacer layer30a. The first portion of spacer layer30bextends in the lateral direction.

The second portion of spacer layer30bis disposed further from semiconductor light-emitting element41than first pad electrode31pand first metal layer31are in the lateral direction. In other words, first pad electrode31pand first metal layer31are disposed between the second portion of spacer layer30band semiconductor light-emitting element41in the lateral direction. The second portion of spacer layer30bis connected to the first portion and extends in the optical axis direction.

The third portion of spacer layer30bis disposed at a position forward from emission surface41F. The third portion of spacer layer30bis connected to the second portion and extends in the lateral direction.

The fourth portion of spacer layer30bis disposed further from semiconductor light-emitting element41than second pad electrode32pand second metal layer32are in the lateral direction. In other words, second pad electrode32pand second metal layer32are disposed between the fourth portion of spacer layer30band semiconductor light-emitting element41in the lateral direction. The fourth portion of spacer layer30bis connected to the third portion and extends in the optical axis direction.

The fifth portion of spacer layer30bis disposed at a position rearward from rear end surface41R in the optical axis direction. The fifth portion of spacer layer30bis disposed further from semiconductor light-emitting element41than second metal layer32is in the lateral direction. In other words, second metal layer32is disposed between the fifth portion of spacer layer30band semiconductor light-emitting element41in the lateral direction. In addition, first metal layer31is disposed between the fifth portion of spacer layer30band spacer layer30a. The fifth portion of spacer layer30bis connected to the fourth portion and extends in the lateral direction.

The advantageous effects resulting from this configuration will be described with reference toFIG.6AandFIG.6B. The wiring substrate of the comparison example illustrated inFIG.6Ais a wiring substrate resulting from removing spacer layers30aand30bfrom wiring substrate20according to the present embodiment.

First metal layer31and second metal layer32according to the comparison example and the present embodiment have a large cross-sectional area such that a large amount of current can be supplied to semiconductor light-emitting element41. For this reason, the thickness of first metal layer31and second metal layer32is approximately greater than or equal to 0.02 mm and less than or equal to 0.15 mm. Second insulating layer22above each of the metal layers as described above is formed by applying and curing a liquid insulating material on first metal layer31and second metal layer32, and has a thickness approximately greater than or equal to 0.02 mm and less than or equal to 0.1 mm. Accordingly, the upper surface of second insulating layer22has an uneven shape along the upper surface of first insulating layer21and each of the metal layers, as illustrated in cross-sectional view (a) ofFIG.6A. In other words, on the upper surface of the wiring substrate, in the region between first metal layer31and second metal layer32, a recess of approximately the same depth as the thickness of first metal layer31and second metal layer32is formed.

When a wiring substrate of the comparison example in which a spacer is not disposed as illustrated inFIG.6Ais used, a large gap is formed between the recess of the upper surface of the wiring substrate and cap unit50. In view of the above, in order to fill the gap between the wiring substrate and the cap unit with a bonding material, a method is conceivable in which the bonding material is applied to the wiring substrate to be in a predetermined thickness, and the bonding material is pressed and crushed by the cap unit to fill the gap. In this case, a large amount of bonding material is used to form in advance a bonding material layer that is sufficiently thicker than the height of the unevenness on the surface of the wiring substrate, along the position of bonding surface50b. Accordingly, when the bonding material layer is pressed and crushed, an unnecessary bonding material can protrude from the bonding surface between the wiring substrate and the cap unit, and spread over the wiring substrate toward opening21aand connector70. This causes the functions of the functional components disposed inside and outside the cap unit to be changed. In particular, when the bonding material spreads toward through-holes28aand28band positioning holes29aand29b, the shapes of the holes may change in some cases. In addition, when the bonding material spreads from the bonding surface facing light-emitting point41etoward semiconductor light-emitting element41, there is a possibility that the properties of emitted light L1change significantly. When the distance between the bonding surface and the functional component is increased so as to reduce the effect of the bonding material that protrudes, it becomes difficult to reduce the size of the semiconductor light-emitting device. When wiring substrate20and cap unit50are to be bonded with a small amount of bonding material, gap55vwhere no bonding material55is present is formed between the upper surface of the wiring substrate and bonding surface50bof cap unit50, as illustrated in cross-sectional view (b) ofFIG.6A. As such, when the wiring substrate of the comparison example is used, it is not possible to seal the gap between the upper surface of the wiring substrate and bonding surface50bof cap unit50.

On the other hand, with wiring substrate20according to the present embodiment, as illustrated in cross-sectional view (a) ofFIG.6B, spacer layers30aand30bare disposed between bonding surface50band first insulating layer21, at positions different from the positions at which first metal layer31and second metal layer32are disposed. Since such spacer layers30aand30bare disposed between first metal layer31and second metal layer32, etc., it is possible to reduce width and depth of the recess, in the direction parallel to the main surface of metal substrate28, formed in upper surface20aof wiring substrate20between first metal layer31and second metal layer32. As a result, as illustrated in cross-sectional view (b) ofFIG.6B, it is possible to fill the recess in upper surface20aof wiring substrate20with a small amount of bonding material55. For this reason, it is possible to seal the gap between upper surface20aof wiring substrate20and bonding surface50bof cap unit50with a small amount of bonding material. It thus is possible to inhibit foreign matter, etc. from entering cap unit50and inhibit the bonding material from affecting the functional components located in proximity to the bonding surface. In other words, semiconductor light-emitting device10with high reliability can be implemented. In addition, since first metal layer31and second metal layer32each having a large cross-sectional area are used, a large amount of current can be applied to semiconductor light-emitting device10to achieve an increase in optical output.

In addition, according to the present embodiment, as illustrated inFIG.5, spacer layers30aand30bare disposed along a portion of bonding surface50bbetween the portion of bonding surface50bfacing first metal layer31and the portion of bonding surface50bfacing second metal layer32. With this configuration, it is possible to increase the portion where any of the metal layers or the spacer layers are disposed between bonding surface50band wiring substrate20. As a result, it is possible to reduce the possibility of formation of a gap between bonding surface50band wiring substrate20. In addition, spacer layer30ahas a linear shape in a top view of wiring substrate20, and is disposed along a portion of bonding surface50bhaving a linear shape between the portion of bonding surface50babove first metal layer31and the portion of bonding surface50babove second metal layer32. Spacer layer30bhas a C-shape in the top view of wiring substrate20, and is disposed along a portion of bonding surface50bhaving a C-shape between the portion of bonding surface50babove first metal layer31and the portion of bonding surface50babove second metal layer32. With this configuration, it is possible to fill most of the space between bonding surface50band metal substrate28where first metal layer31and second metal layer32are not disposed, by spacer layers30aand30b. As a result, it is possible to further reduce the possibility of formation of a gap between bonding surface50band wiring substrate20.

According to the present embodiment, the thicknesses of spacer layers30aand30bare equal to the thicknesses of first metal layer31and second metal layer32. In addition, first metal layer31, second metal layer32, and spacer layers30aand30bare covered by second insulating layer22with the same thickness. With this configuration, it is possible to further flatten upper surface20aof wiring substrate20. As a result, it is possible to further reduce the possibility of formation of a gap between bonding surface50band wiring substrate20. Furthermore, by covering each of the metal layers and each of the spacer layers with second insulating layer22, it is possible to reduce the possibility of disconnection of each of the metal layers due to contact with an external object.

In addition, the distance (i.e., gap) between first metal layer31and each of spacer layers30aand30bis smaller than the width of first metal layer31(i.e., the dimension of first metal layer31in the direction perpendicular to the extending direction and thickness direction). In addition, the distance between second metal layer32and each of spacer layers30aand30bis smaller than the width of second metal layer32. With this configuration, it is possible to further reduce the dimension of the recess formed in upper surface20aof wiring substrate20. In addition, the distance between spacer layer30aand each of first metal layer31and second metal layer32may be made smaller than the width of spacer layer30a. Moreover, the distance between spacer layer30band each of first metal layer31and second metal layer32may be made smaller than the width of spacer layer30b. With this configuration, it is possible to further reduce the dimensions of the recess formed in upper surface20aof wiring substrate20. As a result, it is possible to further reduce the possibility of formation of a gap between bonding surface50band wiring substrate20. It should be noted that, the distance between first metal layer31and each of spacer layers30aand30bmay be greater than the width of first metal layer31. In addition, the distance between second metal layer32and each of spacer layers30aand30bmay be greater than the width of second metal layer32. With this configuration, when spacer layers30aand30bcomprise metal, it is possible to inhibit short circuit between first metal layer31and second metal layer.

Next, a design example of each of the metal layers will be described with reference toFIG.7toFIG.9.FIG.7is a schematic view illustrating each dimension of first metal layer31according to the present embodiment.FIG.8is a graph indicating the relationship between the applied current, operating voltage, and optical output of semiconductor light-emitting device10according to the present embodiment.FIG.9is a table indicating the design examples of the metal layer.

FIG.7illustrates a schematic view of first metal layer31as one example of each of the metal layers. As illustrated inFIG.7, W denotes the width of the cross-section surface perpendicular to the extending direction of the metal layer, T denotes the thickness, and L denotes the length in the extending direction. InFIG.7, first insulating layer21above which first metal layer31is disposed is also indicated. It should be noted that the dimensions of the other metal layers other than first metal layer31are defined in the same manner as first metal layer31.

Electrical wiring comprising a metal layer has a slight (electrical) resistance. However, when power is supplied to semiconductor light-emitting element41that is high in optical output, even a slight resistance of the electrical wiring cannot be ignored because the amount of current that is supplied is large. For example, a current approximately greater than or equal to 1 ampere and less than or equal to 50 amperes, and a voltage approximately greater than or equal to 2 volts and less than or equal to 6 volts are applied to semiconductor light-emitting element41with a high optical output approximately greater than or equal to 1 watt and less than or equal to 100 watts. For example, when semiconductor light-emitting element41with an applied current of 2 amperes and an operating voltage of 2 volts is used, the voltage drop in the electrical wiring is 0.2 V, even when the wiring resistance is 0.1Ω. In other words, the operating voltage increases by 0.2V. For this reason, wiring resistance cannot be ignored as a factor that increases the operating voltage of semiconductor light-emitting device10.

As illustrated inFIG.8, for applied current If, the operating voltage is Va when the resistance of the electrical wiring is low (see the thin solid line inFIG.8), whereas when the resistance of the electrical wiring is high, the operating voltage is Vb which is higher than Va (see the dashed lines inFIG.8). When the resistance of the electrical wiring is high, the amount of heat generated in the electrical wiring is greater than in the case where the resistance is low. The decrease in the optical output of semiconductor light-emitting element41due to the increase in the amount of heat generated may be prevented by discharging heat by a heat sink or the like. However, the supplied power-to-optical conversion efficiency of semiconductor light-emitting device10, namely, Wall-Plug-Efficiency, is Po/(Va·If) when the resistance of the electrical wiring is low, while it decreases to Po/(Vb·If) when the resistance of the electrical wiring is high. In particular, in a light source device or the like that uses a plurality of semiconductor light-emitting devices10, the effect of the decrease in conversion efficiency on power consumption becomes more noticeable.

The following describes in detail a method of reducing the resistance of electric wiring that comprise a metal layer as described above.

According to the conventional techniques, ceramic and a metal layer are integrally sintered to form electrical wiring, and thus the metal layer is formed using conductive paste that comprises, as a main component, tungsten which is a material suitable for integrated sintering. However, tungsten has a relatively large volume resistivity of approximately 5.7×10−8Ω·m, which is likely to be a factor of an increase in wiring resistance.

According to the present embodiment, the metal layer comprises copper which has a relatively low volume resistivity of approximately 1.8×10−8Ω·m, or a material including copper as the main component.

In addition, according to the conventional techniques, the metal layer is formed inside the ceramic, and thus it is necessary to increase the adhesion between the metal layer and the ceramic. As a result, it is necessary to reduce thickness T of the metal layer to be smaller than, for example, 50 μm. In addition, thickness T of the metal layer may be smaller than 20 μm, for example. With this configuration, it is possible to reduce the formation of unevenness on the surface of the ceramic layer. In such a case, a restriction is added to the design conditions of the metal layer to reduce the wiring resistance. For example, when tungsten is used as the material of the metal layer, as illustrated inFIG.9, thickness T and width W of the metal layer are small in design example 1, and thus the wiring resistance becomes large. For this reason, the operating voltage increases by 0.228 V due to the wiring resistance. Therefore, when the amount of applied current is large, it is necessary to increase thickness T and width W as in design example 2.

According to the present embodiment, as indicated in design example 4 ofFIG.9, the dimensions of the metal layer are approximately the same as those of design example 2 of the conventional technique, and the material is changed to copper from tungsten of design example 2. With this configuration, it is possible to reduce the wiring resistance to approximately one third of the wiring resistance of design example 2. As a result, it is possible to reduce the voltage increase due to wiring resistance to less than or equal to 1% of the operating voltage.

It should be noted that, by using copper as the material of the metal layer, as indicated in design example 3, it is possible to reduce the wiring resistance to approximately one third of the wiring resistance of design example 1, even with the same thickness T and width W as those of design example 1.

In addition, when the amount of applied current is larger as indicated in design example 5 and design example 6 ofFIG.9, for example, it is possible to inhibit an increase in operating voltage due to wiring resistance, by increasing at least one of thickness T or width W.

As indicated in design examples 4 to 6 ofFIG.9, thickness T of the metal layers comprising first metal layer31and second metal layer32may be greater than or equal to 0.05 mm. With this configuration, it is possible to reduce the resistance in first metal layer31and second metal layer32. Accordingly, a protrusion having a height higher than or equal to 0.05 mm is formed above upper surface20aof wiring substrate20. In addition, when each of the metal layers and first insulating layer21are covered using resin or the like such as a resist as second insulating layer22, it is also difficult to flatten upper surface20aof wiring substrate20because second insulating layer22has a thickness approximately greater than or equal to 0.02 mm and less than or equal to 0.1 mm. In addition, the width of each of the metal layers may be greater than or equal to 1 mm. This configuration allows a reduction in the wiring resistance of each of the metal layers. In addition, in order to reduce the wiring resistance, the length of each of the metal layers need to be as short as possible. For this reason, first metal layer31and second metal layer32connect first pad electrode31pand second pad electrode32p, respectively, to connector70in the shortest distance, for example, in a straight line. For this reason, the gap between first metal layer31and second metal layer32is approximately greater than or equal to 1 mm, for example. In this case, even when cap unit50and wiring substrate20are bonded with bonding material55, a gap having a space of, for example, approximately 0.01 mm or more in the thickness direction and approximately 0.1 mm or more in the width direction is created between cap unit50and wiring substrate20. For this reason, the gap between cap unit50and wiring substrate20cannot be sealed.

According to the present embodiment, with spacer layers30aand30b, it is possible to narrow the width of the recess between each of the metal layers and a corresponding one of the spacer layers to be, for example, less than or equal to 0.3 mm. With this configuration, the gap between cap unit50and wiring substrate20can be filled with bonding material55. As a result, it is possible to seal the gap between cap unit50and wiring substrate20.

In addition, with wiring substrate20according to the present embodiment, it is not necessary to provide wiring in the substrate, and thus the configuration is simplified.

It should be noted that although the same material as each of the metal layers has been used as the material that each of the spacer layers comprises according to the present embodiment, the material that each of the spacer layers can comprise is not limited to this. For example, in the process illustrated inFIG.10B, after forming only each of the metal layers without forming each of the spacer layers, a resin film such as a polyimide film having substantially the same thickness as the thickness of each of the metal layers may be formed and used as a spacer layer, for example. With this configuration, it is possible to inhibit each of the metal layers from short-circuiting with the other metal layers through the spacer layer.

1-3. Manufacturing Method

Next, a method of manufacturing semiconductor light-emitting device10according to the present embodiment will be described. First, a manufacturing method of wiring substrate20will be described with reference toFIG.10AtoFIG.10G.FIG.10AtoFIG.10Gare cross-sectional views schematically illustrating the respective processes of the manufacturing method of wiring substrate20according to the present embodiment.

First, as metal substrate28, a flat plate of oxygen-free copper having a thickness of 2 mm, for example, is prepared as illustrated inFIG.10A. Then, above metal substrate28, insulating substrate21M comprising, for example, epoxy glass prepreg is disposed as a material to form first insulating layer21. Next, metal foil30M comprising a copper foil having a thickness of 0.08 mm, for example, is disposed above insulating substrate21M as a material for forming each of the metal layers and each of the spacer layers. Then, metal substrate28, insulating substrate21M, and metal foil30M are overlapped, pressurized, and heated to form an integral substrate as illustrated inFIG.10A.

Then, as illustrated inFIG.10B, metal foil30M is patterned by etching to form first metal layer31, second metal layer32, and spacer layers30aand30b. It should be noted that, in the cross section illustrated inFIG.10B, first metal layer31and second metal layer32are not illustrated, and third metal layer33and fourth metal layer34are illustrated. As described above, third metal layer33and fourth metal layer34may be formed from metal foil30M in this process

Then, as illustrated inFIG.10C, resist22M is formed above insulating substrate21M, each of the metal layers, and each of the spacer layers.

Then, as illustrated inFIG.10D, second insulating layer22is formed by patterning resist22M by a photographic method. In second insulating layer22, opening21aof first insulating layer21, and openings22ato22dfor forming each of the pad electrodes are formed.

Then, as illustrated inFIG.10E, first insulating layer21having opening21ais formed by removing the portion of insulating substrate21M that is exposed from opening22a, by means of laser trimming.

Then, as illustrated inFIG.10F, protection film25such as Au is formed on each metal surface exposed from opening21aand openings22bto22d, by means of an electroless plating method.

Then, as illustrated inFIG.10G, wiring substrate20is formed by singulating metal substrate28above which first insulating layer21, etc. are formed, using cutter CT or the like. At this time, it is possible to form slanted cut surface28cof an arbitrary shape on wiring substrate20, by adjusting the blade shape of cutter CT. For example, it is possible to easily form slanted cut surface28cby using a rotating blade having a tapered blade.

Next, the manufacturing method of cap unit50will be described with reference toFIG.11.FIG.11is a perspective view schematically illustrating the manufacturing method of cap unit50according to the present embodiment. As illustrated inFIG.11, cap unit50includes side wall51that is a light-transmissive window and holder52. Side wall51is, for example, a light-transmissive window including: inorganic light-transmissive plate51acomprising a thin glass substrate having a rectangular shape and thickness Dg greater than or equal to 0.01 mm and less than or equal to 0.2 mm; and antireflection films51band51ccomprising dielectric multilayer films such as SiO2, Ta2O5, and TiO2and disposed on both sides of inorganic light-transmissive plate51a. Holder52is a box-shaped component lacking one side wall, and includes three side walls52a,52b, and52cconnected to three sides of the peripheral edge of top plate52dthat is transparent and has a rectangular shape. Holder52is manufactured, for example, by forming a recess in a glass block having a rectangular parallelepiped shape by means of sandblasting, etc., and dividing it.

Side wall51and holder52are bonded by optical contact or laser bonding to form cap unit50having a box shape.

Thickness Ds of each of the side walls of holder52is, for example, approximately greater than or equal to 0.3 mm and less than or equal to 2 mm, which is greater than the thickness of side wall51. For this reason, even when side wall51that is thinner than side walls52a,52b, and52cis used, holder52that is structurally strong with side walls52a,52b, and52cwhich are relatively thick holds side wall51, and thus it is possible to inhibit side wall51from being damaged. In addition, side wall51and holder52comprise the same material, and thus it is possible to inhibit damage due to expansion and contraction caused by temperature.

Next, the method of attaching wiring substrate20to cap unit50according to the present embodiment will be described with reference toFIG.12AandFIG.12B.FIG.12Ais a cross-sectional view schematically illustrating the method of attaching cap unit50to wiring substrate20according to the present embodiment. In wiring substrate20manufactured according to the above-described manufacturing method, semiconductor light-emitting element41and submount45have been mounted and a metal wire which is not illustrated has been attached in advance, before cap unit50is attached.FIG.12Aillustrates a cross-section surface perpendicular to wiring substrate20through the optical axis of semiconductor light-emitting element41.FIG.12Bis a cross-sectional view schematically illustrating a light source device using semiconductor light-emitting device10according to the present embodiment.

According to the present embodiment, top plate52dof cap unit50is transparent, and thus it is possible to adjust the position of cap unit50with high precision without contact between side wall51which is a light-transmissive window and the emission surface of semiconductor light-emitting element41, as illustrated inFIG.12A. For example, as illustrated inFIG.12A, the position of cap unit50may be adjusted while observing a magnified image of cap unit50and semiconductor light-emitting element41from above cap unit50, using image observation system91. This makes it possible to adjust the position of cap unit50such that the distance between side wall51and the emission surface of semiconductor light-emitting element41is less than the thickness of side wall51.

In addition, it is possible to reduce the distance between semiconductor light-emitting element41and the outside of cap unit50, by using thin side wall51.

In addition, wiring substrate20includes a spacer, and wiring substrate20and side wall51of cap unit50are bonded above the spacer. With this configuration, a small amount of bonding material is sufficient to bond the gap between wiring substrate20and side wall51, and thus it is possible to inhibit an excess bonding material from reaching the vicinity of semiconductor light-emitting element41that is located in close proximity and changing the properties of emitted light L1.

By reducing the distance between semiconductor light-emitting element41and the outside of cap unit50, for example, as illustrated inFIG.12B, in a light source device including semiconductor light-emitting device10and lens optical element92that is a fast axis collimator lens, it is possible to reduce distance DL between the emission surface of semiconductor light-emitting element41and lens optical element92. With this configuration, it is possible to reduce the beam width in the fast axis direction of the laser light (emitted light L1) emitted from semiconductor light-emitting device10.

At this time, the distance resulting from adding thickness Dg of side wall51and gap Dgap between side wall51and the emission surface should be short. By making gap Dgap smaller than thickness Dg of side wall51, it is possible to bring lens optical element92close to the emission surface of semiconductor light-emitting element41while maintaining the strength of side wall51.

According to the above-described configuration, semiconductor light-emitting device10according to the present embodiment is capable of causing semiconductor light-emitting element41to emit emitted light L1with a large optical output, by applying a large amount of current to semiconductor light-emitting element41with a small wiring resistance. In addition, semiconductor light-emitting element41above wiring substrate20is sealed by cap unit50, and thus it is possible to improve the reliability of semiconductor light-emitting element41. Furthermore, the distance between light-emitting point41eof semiconductor light-emitting element41and the outside of cap unit50is reduced. Accordingly, it is possible to more freely design external optical elements such as lens optical elements which are disposed outside10and are optically coupled to light-emitting point41e. In addition, as illustrated inFIG.4, slanted cut surface28cis formed on the end portion on the upper surface20aside of metal substrate28of the wiring substrate. With this configuration, it is possible to inhibit a portion of emitted light L1from being blocked outside the semiconductor light-emitting device, and also to more freely place the external optical elements. In addition, the Joule heat generated in semiconductor light-emitting element41is spread in metal substrate28and dissipated from heat-dissipating surface20bto an external heat sink. At this time, since semiconductor light-emitting element41is mounted above metal substrate28without involving first insulating layer21and second insulating layer22, the Joule heat is efficiently transferred to metal substrate28. Furthermore, metal substrate28has a larger area on the lower surface than on the upper surface due to slanted cut surface28cformed in the end portion. For this reason, the Joule heat that has been generated is transferred from submount45to metal substrate28as heat flow TP1and TP5illustrated inFIG.4, and then spread in a direction parallel to the upper surface of metal substrate28and efficiently dissipated to the outside. As a result, it is possible to cause emitted light L1which is high in optical output to be emitted from semiconductor light-emitting element41.

Next, a semiconductor light-emitting device according to Variation 1 of the present embodiment will be described. The semiconductor light-emitting device according to the present variation differs from semiconductor light-emitting device10according to Embodiment 1 in the configuration of the spacer layer, and matches in the other configurations. The following describes the semiconductor light-emitting device according to the present variation with a focus on the difference from semiconductor light-emitting device10according to Embodiment 1, with reference toFIG.13A.

FIG.13Ais a top view schematically illustrating the configuration of spacer layers130aand130bof semiconductor light-emitting device110according to the present variation.FIG.13Aillustrates the configuration of semiconductor light-emitting element41and the surroundings of semiconductor light-emitting device110in a state in which cap unit50and second insulating layer22are removed. As illustrated inFIG.13A, spacer layers130aand130baccording to the present variation comprise the material that second metal layer32comprises, and are electrically connected to second metal layer32. More specifically, spacer layers130aand130band second metal layer32have the same thickness, and the top surfaces of each of the spacer layers and second metal layer32are flat and connected. In other words, the upper surfaces of each of the spacer layers and second metal layer32are connected in a state in which they are flush with each other. The boundary between second metal layer32and each of the spacer layers may be set as appropriate. According to the present embodiment, second metal layer32is defined as a rectangular-shaped portion extending in the optical axis direction. Spacer layer130ais disposed in a region located rearward from rear end surface41R of semiconductor light-emitting element41on the side opposite to emission surface41F including light-emitting point41e. Spacer layer130aextends in the lateral direction between first metal layer31and second metal layer32. According to the present variation, spacer layer130ais connected to an end edge of second metal layer32on the side closer to first metal layer31. In other words, spacer layer130aprotrudes from second metal layer32in a direction toward first metal layer31. Spacer layer130bis composed of five portions.

The first portion of spacer layer130bis disposed at a position rearward from rear end surface41R. The first portion of spacer layer130bis disposed further from semiconductor light-emitting element41than first metal layer31is in the lateral direction. In other words, first metal layer31is disposed between the first portion of spacer layer130band semiconductor light-emitting element41. In addition, first metal layer31is disposed between the first portion of spacer layer130band spacer layer130a. The first portion of spacer layer130bextends in the lateral direction.

The second portion of spacer layer130bis disposed further from semiconductor light-emitting element41than first pad electrode31pand first metal layer31are in the lateral direction. In other words, first pad electrode31pand first metal layer31are disposed between the second portion of spacer layer130band semiconductor light-emitting element41in the lateral direction. The second portion of spacer layer130bis connected to the first portion and extends in the optical axis direction.

The third portion of spacer layer130bis disposed at a position forward from emission surface41F. The third portion of spacer layer130bis connected to the second portion and extends in the lateral direction.

The fourth portion of spacer layer130bis disposed further from semiconductor light-emitting element41than second pad electrode32pand second metal layer32are in the lateral direction. In other words, second pad electrode32pand second metal layer32are disposed between the fourth portion of spacer layer130band semiconductor light-emitting element41in the lateral direction. The fourth portion of spacer layer130bis connected to the third portion and extends in the optical axis direction.

The fifth portion of spacer layer130bis disposed at a position rearward from rear end surface41R in the optical axis direction. The fifth portion of spacer layer130bis disposed further from semiconductor light-emitting element41than second metal layer32is in the lateral direction. In other words, second metal layer32is disposed between the fifth portion of spacer layer130band semiconductor light-emitting element41in the lateral direction. In addition, second metal layer32is disposed between the fifth portion of spacer layer130band spacer layer130a. The fifth portion of spacer layer130bis connected to the fourth portion and extends in the lateral direction.

Such spacer layers130aand130bcan be formed at the same time as second metal layer32in the process of forming each of the metal layers in the same manner as each of the spacer layers according to Embodiment 1. It should be noted that, also in the case where each of the spacer layers is in contact with second metal layer32as in the present variation, each of the spacer layers is disposed at a position different from the position at which second metal layer32is disposed.

With spacer layers130aand130baccording to the present variation, the gap between second metal layer32and each of the spacer layers is zero, and thus a recess is not formed, above the upper surface of the wiring substrate, at the position corresponding to the gap between second metal layer32and each of the spacer layers. As a result, it is possible to reduce the formation of a gap between bonding surface50bof cap unit50and the upper surface of the wiring substrate. In other words, it is possible to more securely seal bonding surface50bof cap unit50and the upper surface of the wiring substrate.

Although each of the spacer layers has been connected to second metal layer32in the present variation, each of the spacer layers may be connected to first metal layer31. In this case, spacer layers130aand130bmay comprise the material that first metal layer31comprises. In other words, spacer layers130aand130bmay comprise the material that one of first metal layer31or second metal layer32comprises, and be electrically connected to the one of first metal layer31or second metal layer32.

Next, a semiconductor light-emitting device according to Variation 2 of the present embodiment will be described. The semiconductor light-emitting device according to the present variation differs from semiconductor light-emitting device10according to Embodiment 1 in the configuration of the spacer layer, and matches in the other configurations. The following describes the semiconductor light-emitting device according to the present variation with a focus on the difference from semiconductor light-emitting device10according to Embodiment 1, with reference toFIG.13B.

FIG.13Bis a top view schematically illustrating the configuration of spacer layers30a,30b, and30cof semiconductor light-emitting device110aaccording to the present variation.FIG.13Billustrates the configuration of semiconductor light-emitting element41and the surroundings of semiconductor light-emitting device110ain a state in which cap unit50and second insulating layer22are removed. As illustrated inFIG.13B, semiconductor light-emitting device110aaccording to the present variation includes four spacer layers30cin addition to spacer layers30aand30bequivalent to those according to Embodiment 1. Spacer layers30care insulating films disposed between the respective metal layers and spacer layers30aand30b. For example, an inorganic material such as resin, low-melting-point glass, etc. can be used as the material which spacer layers30ccomprise. It should be noted that, when spacer layers30aand30bcomprise an insulating material, spacer layers30cmay comprise a metal material.

With the wiring substrate according to the present variation, the gap between each of the metal layers and spacer layers30aand30bcan be filled with spacer layers30c, and thus it is possible to reduce the dimensions of the recess formed in the upper surface of the wiring substrate compared to wiring substrate20according to Embodiment 1. As a result, it is possible to reduce the formation of a gap between bonding surface50bof cap unit50and the upper surface of the wiring substrate. In other words, it is possible to more securely seal bonding surface50bof cap unit50and the upper surface of the wiring substrate.

In addition, the thickness of each of spacer layer30cmay be the same as each of the metal layers and spacer layers30aand30b. With this configuration, it is possible to further reduce the dimensions of the recess formed in the upper surface of the wiring substrate.

Next, a semiconductor light-emitting device according to Variation 3 of the present embodiment will be described. The semiconductor light-emitting device according to the present variation matches semiconductor light-emitting device10according to Embodiment 1 in points other than that a shielding component disposed between temperature sensing element60and semiconductor light-emitting element41is included. The following describes the semiconductor light-emitting device according to the present variation with a focus on the difference from semiconductor light-emitting device10according to Embodiment 1, with reference toFIG.14AandFIG.14B.

FIG.14AandFIG.14Bare a top view and a cross-sectional view, respectively, each schematically illustrating the positional relationship of semiconductor light-emitting element41, temperature sensing element60, and shielding component60sof semiconductor light-emitting device110baccording to the present variation.FIG.14Bis a cross-sectional view of semiconductor light-emitting element41ofFIG.14Aat optical axis LA1. As illustrated inFIG.14AandFIG.14B, semiconductor light-emitting device110baccording to the present variation includes shielding component60sdisposed between temperature sensing element60and semiconductor light-emitting element41.

As illustrated inFIG.14B, semiconductor light-emitting element41emits emitted light L1B also from rear end surface41R that is an end surface on the opposite side from the emission surface at which light-emitting point41eis located. The intensity of emitted light L1B is much smaller than the intensity of emitted light L1. However, when semiconductor light-emitting element41is a high optical output element, the intensity of emitted light LIB also relatively increases. For this reason, when temperature sensing element60is irradiated with emitted light LIB, the temperature of temperature sensing element60increases, making it impossible to accurately sense the temperature of wiring substrate20. According to the present variation, shielding component60sis disposed between temperature sensing element60and rear end surface41R of semiconductor light-emitting element41. In other words, semiconductor light-emitting element41, shielding component60s, and temperature sensing element60are arranged on optical axis LA1in stated order. With this configuration, it is possible to shield emitted light L1B by shielding component60s. In addition, shielding component60sis not particularly limited as long as it can shield emitted light LIB, and for example, may be the same element as temperature sensing element60. When such an element is used as shielding component60s, no wiring is connected to the element. By disposing an element of the same dimensions as temperature sensing element60between temperature sensing element60and semiconductor light-emitting element41, it is possible to reliably inhibit temperature sensing element60from being irradiated with emitted light LIB. In addition, the dimensions of shielding component60smay be larger than the dimensions of temperature sensing element60. With this configuration, it is possible to more reliably inhibit emitted light LIB from being incident on temperature sensing element60. It should be noted that shielding component60smay be disposed outside cap unit50or inside cap unit50.

Next, a semiconductor light-emitting device according to Embodiment 2 will be described. The semiconductor light-emitting device according to the present embodiment differs from semiconductor light-emitting device10according to Embodiment 1 mainly in the configurations of the first metal layer and the second metal layer. The following describes the semiconductor light-emitting device according to the present embodiment focusing on the differences from semiconductor light-emitting device10according to Embodiment 1.

2-1. Overall Configuration

First, the overall configuration of the semiconductor light-emitting device according to the present embodiment will be described with reference toFIG.15toFIG.17.FIG.15andFIG.16are a perspective view and an exploded perspective view, respectively, each of which schematically illustrates the overall configuration of semiconductor light-emitting device210according to the present embodiment.FIG.17is cross-sectional view schematically illustrating the overall configuration of semiconductor light-emitting device210according to the present embodiment.FIG.17illustrates a cross-section surface that is taken along line XVII-XVII ofFIG.16, and is perpendicular to upper surface220aof wiring substrate220.

As illustrated inFIG.15toFIG.17, semiconductor light-emitting device210according to the present embodiment includes wiring substrate220, cap unit50, and connector270. In addition, as illustrated inFIG.16andFIG.17, semiconductor light-emitting device210further includes semiconductor light-emitting element41, submount45, and temperature sensing element60. In addition, as illustrated inFIG.17, semiconductor light-emitting device210further includes bonding materials226,42, and62, and bonding layer255. The following describes each of the structural components of semiconductor light-emitting device210.

Wiring substrate220according to the present embodiment includes metal substrate228, first insulating layer221, second insulating layer222, third metal layer233, fourth metal layer234, and protection film225, as illustrated inFIG.17. In addition, as illustrated inFIG.16, wiring substrate220further includes first metal layer231, second metal layer232, spacer layers230a,230b, and230c, first pad electrode231p, second pad electrode232p, first extraction electrode237, and second extraction electrode238.

According to the present embodiment, in the same manner as Embodiment 1, through-holes228aand228band positioning holes229aand229bare provided in wiring substrate220. Through-holes228aand228band positioning holes229aand229baccording to the present embodiment differ from through-holes28aand28band positioning holes29aand29baccording to Embodiment 1 in their arrangement in wiring substrate220. According to the present embodiment, positioning holes229aand229bare located in proximity to the rear end portion of wiring substrate220. Here, the rear end portion of wiring substrate220is an end portion out of the two end portions of wiring substrate220in the direction of propagation of emitted light L1, which is farther from light-emitting point41e. Through-holes228aand228bare located in proximity to the center of wiring substrate220in the propagation direction of emitted light L1.

Metal substrate228differs from metal substrate28according to Embodiment 1 in their arrangement and a total number of the holes provided, and matches in the other points.

First insulating layer221is an insulating layer having a configuration equivalent to the configuration of first insulating layer21according to Embodiment 1, and opening221ais formed therein.

First metal layer231, second metal layer232, third metal layer233, and fourth metal layer234are metal layers spaced apart from each other above first insulation layer221. According to the present embodiment, first metal layer231extends from first pad electrode231pin the direction perpendicular to the propagation direction of emitted light L1and parallel to the main surface of metal substrate228, as illustrated inFIG.16, and is connected to first extraction electrode237. Specifically, first metal layer231extends from the gap between first pad electrode231pand first insulating layer221to the gap between first extraction electrode237and first insulating layer221. Second metal layer232extends from second pad electrode232pin the direction perpendicular to the propagation direction of emitted light L1and parallel to the main surface of metal substrate228, and is connected to second extraction electrode238, as illustrated inFIG.16. Specifically, second metal layer232extends from the gap between second pad electrode232pand first insulating layer221to the gap between second extraction electrode238and first insulating layer221. Second metal layer232extends in the direction opposite to the direction in which first metal layer231extends. As described above, according to the present embodiment, first metal layer231and second metal layer232are not connected to connector270. Current is supplied to semiconductor light-emitting element41via first extraction electrode237and second extraction electrode238, without involving connector270. First metal layer231and second metal layer232have the configuration as illustrated in design example 6 inFIG.9. In other words, first metal layer231and second metal layer and232are copper films each having thickness T of 0.070 mm, width W of 7.0 mm, and length L of 5 mm. This allows the resistance of first metal layer231and second metal layer232to be 0.0002Ω. As a result, even when a large amount of current of approximately 30 A is supplied to semiconductor light-emitting element41, it is possible to suppress the increase in operating voltage due to the resistance of each of the metal layers to be approximately 0.006 V.

Third metal layer233and fourth metal layer234are wiring connected to temperature sensing element60, in the same manner as third metal layer33and fourth metal layer34according to Embodiment 1. According to the present embodiment, as illustrated inFIG.16andFIG.17, temperature sensing element60is disposed inside cap unit50, and thus the arrangement of third metal layer233and fourth metal layer234in wiring substrate220is different from the arrangement of third metal layer33and fourth metal layer34according to Embodiment 1. According to the present embodiment, as illustrated inFIG.16, third metal layer233and fourth metal layer234are disposed at positions rearward from rear end surface41R located opposite to emission surface41F of semiconductor light-emitting element41and extend in the optical axis direction. Bonding surface50bof cap unit50which is bonded to wiring substrate220intersects third metal layer233and fourth metal layer234in the top view of wiring substrate220.

First pad electrode231pand second pad electrode232phave configurations equivalent to the configurations of first pad electrode31pand second pad electrode32paccording to Embodiment 1, respectively, as illustrated inFIG.16.

Spacer layers230a,230b, and230care layers that are disposed at positions different from the positions at which first metal layer231and second metal layer232above first insulating layer221, as illustrated inFIG.16. Spacer layers230a,230b, and230care disposed between first insulating layer221and bonding surface50bof cap unit50with wiring substrate220, in the same manner as each of the spacer layers according to Embodiment 1. Each of the spacer layers forms a protrusion above first insulating layer221in the same manner as each of the metal layers.

Spacer layer230ahas an L-shape in the top view of wiring substrate220and is composed of two portions. The first portion of spacer layer230ais disposed at a position rearward from rear end surface41R in the optical axis direction. The first portion of spacer layer230ais disposed between semiconductor light-emitting element41and first extraction electrode237in the lateral direction. The first portion of spacer layer230aextends in the optical axis direction. The second portion of spacer layer230ais disposed at a position rearward from rear end surface41R of semiconductor light-emitting element41in the optical axis direction. The second portion of spacer layer230ais connected to the first portion and extends in the lateral direction.

Spacer layer230bhas an L-shape in the top view of wiring substrate220and is composed of two portions. The first portion of spacer layer230bis disposed at a position rearward from rear end surface41R in the optical axis direction. In addition, the first portion of spacer layer230bis disposed between semiconductor light-emitting element41and second extraction electrode238in the lateral direction. The first portion of spacer layer230bextends in the optical axis direction. The second portion of spacer layer230bis disposed at a position rearward from rear end surface41R in the optical axis direction. The second position of spacer layer230bis disposed between the first portion of spacer layer230band spacer layer230a. The second portion of spacer layer230bis connected to the first portion and extends in the lateral direction.

Spacer layer230cis composed of three portions. The first portion of spacer layer230cis disposed between semiconductor light-emitting element41and first extraction electrode237in the lateral direction. The first portion of spacer layer230cis disposed at a position forward from first metal layer231in the optical axis direction. The first portion of spacer layer230cextends in the optical axis direction. The second portion of spacer layer230cis disposed at a position forward from emission surface41F. The second portion of spacer layer230cis connected to the first portion and extends in the lateral direction. The third portion of spacer layer230cis disposed between semiconductor light-emitting element41and second extraction electrode238in the lateral direction. The third portion of spacer layer230cis disposed at a position forward from second metal layer232in the optical axis direction. The third portion of spacer layer230cis connected to the second portion and extends in the optical axis direction.

Second insulating layer222is an insulating layer disposed above first insulating layer221as illustrated inFIG.17. Second insulating layer222covers at least a portion of first metal layer231, second metal layer232, third metal layer233, fourth metal layer234, and spacer layers230a,230b, and230c, in the same manner as second insulating layer22according to Embodiment 1.

Protection film225is a metal film disposed, for example, at a position at which submount45is bonded in wiring substrate220, as illustrated inFIG.17. Protection film225is dispose in a region corresponding to opening221aof first insulating layer221of metal substrate228, in the same manner as protection film25according to Embodiment 1. Protection film235is disposed on, for example, a portion of the upper surface of first metal layer231, second metal layer232, third metal layer233, and fourth metal layer234, in the same manner as protection film35according to Embodiment 1. It should be noted that, according to the present embodiment, submount45is disposed inside opening221aof first insulating layer221, and mounted above metal substrate228via bonding material226and protection film225. Bonding material226comprises, for example, AuSn solder or the like.

First extraction electrode237and second extraction electrode238are each an example of the extraction electrode, and are electrically connected to first metal layer231and second metal layer232, respectively. According to the present embodiment, first extraction electrode237and second extraction electrode238are disposed above first metal layer231and second metal layer232, respectively. First extraction electrode237and second extraction electrode238are disposed in proximity to first pad electrode231pand second pad electrode232p, respectively. With this configuration, the lengths of first metal layer231and second metal layer232can be reduced, and thus it is possible to reduce the resistance of first metal layer231and second metal layer232.

First extraction electrode237and second extraction electrode238each have an annular shape, and include, in the center portion, electrode through-hole237aand electrode through-hole238a, respectively, which penetrate through wiring substrate220. Through-holes228aand228bare holes for inserting a fixing component such as a screw when fixing wiring substrate220to closely adhere to a heat sink or the like. According to the present embodiment, electrode through-holes237aand238aare located on one side and the other side of wiring substrate220, respectively, relative to the region in which semiconductor light-emitting element41is disposed. In other words, semiconductor light-emitting element41is disposed between electrode through-hole237aand electrode through-hole238a.

Bonding layer255is a component that bonds bonding surface50bof cap unit50and upper surface220aof wiring substrate220. According to the present embodiment, bonding layer255includes first auxiliary bonding film255a, bonding material255b, and second auxiliary bonding film255c. First auxiliary bonding film255aand second auxiliary bonding film255care metal films disposed above bonding surface50band the upper surface of second insulating layer222, respectively, and comprise Ni, Au, or the like. These auxiliary bonding films allow cap unit50and second insulating layer222to be easily bonded by bonding material255b. Bonding material255bis an alloy material that comprises AuSn solder, or the like.

Temperature sensing element60is an element equivalent to temperature sensing element60according to Embodiment 1. According to the present embodiment, temperature sensing element60is covered by cap unit50as illustrated inFIG.16andFIG.17. With this configuration, temperature sensing element60is not exposed to outside air, and thus the effect of outside air on temperature sensing is suppressed. As a result, it is possible to accurately sense a temperature. Hereinafter, the placement of temperature sensing element60according to the present embodiment will be described with reference toFIG.18.FIG.18is a top view illustrating the placement of temperature sensing element60according to the present embodiment.

As illustrated inFIG.18, temperature sensing element60according to the present embodiment is disposed at a position that does not intersect optical axis LA1of semiconductor light-emitting element41. With this configuration, it is possible to inhibit temperature sensing element60from being irradiated with emitted light L1B emitted from rear end surface41R of semiconductor light-emitting element41, without providing a shielding component. As a result, it is possible to accurately sense the temperature of wiring substrate220by temperature sensing element60.

Connector270is a connecting component including terminals each of which is connected to a corresponding one of third metal layer233and fourth metal layer234. According to the present embodiment, unlike connector70according to Embodiment 1, connector270does not have terminals that are connected to first metal layer231and second metal layer232.

Next, the advantageous effects of semiconductor light-emitting device210according to the present embodiment will be described with reference toFIG.19AtoFIG.19C.FIG.19AtoFIG.19Care each a schematic cross-sectional view which explains the method of bonding cap unit50to wiring substrate220of semiconductor light-emitting device210according to the present embodiment. The cross-section surface illustrated inFIG.19Ais equivalent to that illustrated inFIG.17other than that components other than wiring substrate220and cap unit50are omitted. In addition,FIG.19BandFIG.19Ceach illustrate semiconductor light-emitting device210in a cross-section that is taken along line XIX-XIX indicated inFIG.16and is perpendicular to upper surface220aof wiring substrate220.FIG.19AandFIG.19Beach illustrate the state before cap unit50and wiring substrate220are bonded, andFIG.19Cillustrates the state after cap unit50and wiring substrate220are bonded.

First, as illustrated inFIG.19AandFIG.19B, first auxiliary bonding film255aand bonding material255bare formed above bonding surface50bof cap unit50in stated order. Meanwhile, second auxiliary bonding film255cis formed above upper surface220aof wiring substrate220in the region facing bonding surface50bof cap unit50. As illustrated inFIG.19B, in the same manner as Embodiment 1, it is possible to reduce the dimensions of the recess formed in upper surface220aof wiring substrate220by each of the spacer layers, in the present embodiment as well.

Then, cap unit50is disposed above upper surface220aof wiring substrate220. Wiring substrate220is then heated to melt bonding material255bbetween first auxiliary bonding film255aand second auxiliary bonding film255c. Then, bonding material255bis solidified by cooling wiring substrate220. In this manner, it is possible to bond first auxiliary bonding film255aand second auxiliary bonding film255cby bonding material255b, as illustrated inFIG.19C. At this time, as described above, the dimensions of the recess formed in upper surface220aof wiring substrate220are reduced, and thus it is possible to fill the recess formed in upper surface220aof wiring substrate220by bonding material255b, as illustrated inFIG.19C. As a result, it is possible to seal the gap between cap unit50and wiring substrate220. It is therefore possible, in the same manner as Embodiment 1, to implement semiconductor light-emitting device210which is high in optical output and reliability in the present embodiment as well.

2-3. Light Source Device

Next, a light source device in which semiconductor light-emitting device210according to the present embodiment is used will be described with reference toFIG.20andFIG.21.FIG.20andFIG.21are a perspective view and an exploded perspective view, respectively, each of which schematically illustrates the configuration of light source device201according to the present embodiment.

Heat sink219is a heat-dissipating component comprising a material that is high in thermal conductivity, such as metal. Heat sink219comprises, for example, iron, iron alloy, aluminum, aluminum alloy, copper, or the like. In addition, aluminum alloy having a surface on which alumite treatment has been applied, or copper having a surface on which Ni plating has been applied may also be used. In heat sink219, positioning pins P1and P2and threaded holes T1to T4are formed, as illustrated inFIG.21. Positioning pin P1and positioning pin P2are inserted to positioning hole229aand positioning hole229bof semiconductor light-emitting device210, respectively.

Semiconductor light-emitting device210is fixed to closely adhere to heat sink219, using terminal fixing screws S1and S2, and fixing screws S3and S4. More specifically, fixing screws S3and S4penetrate through through-holes228aand228b, respectively, in the wiring substrate and are fixed to threaded holes T3and T4, respectively, in heat sink219.

Terminal fixing screw S1penetrates through a hole formed in terminal213and electrode through-hole237ain wiring substrate220, and is fixed to threaded hole T1in heat sink219. Terminal fixing screw S1penetrates through electrode through-hole237a, and terminal213is disposed between terminal fixing screw S1and first extraction electrode237. With this configuration, first extraction electrode237and terminal213are electrically connected.

Terminal fixing screw S2is fixed to threaded hole T2in heat sink219through a hole formed in terminal214and electrode through-hole238ain wiring substrate220. Terminal fixing screw S2penetrates through electrode through-hole238a, and terminal214is disposed between terminal fixing screw S2and second extraction electrode238. With this configuration, second extraction electrode238and terminal214are electrically connected.

As described above, it is possible to fix semiconductor light-emitting device210to heat sink219. In this manner, since semiconductor light-emitting device210can be firmly fixed to heat sink219, using terminal fixing screws S1and S2, as well as fixing screws S3and S4, heat generated by the semiconductor light-emitting element41of semiconductor light-emitting device210can be effectively dissipated from metal substrate228to heat sink219.

In addition, according to the above-described configuration, it is possible to electrically connect terminal213and terminal214to first extraction electrode237and second extraction electrode238, respectively. As a result, it is possible to supply a large amount of current to semiconductor light-emitting device210via cables211and212.

It should be noted that fixing screws S3and S4comprise a metal material, for example. On the other hand, for terminal fixing screws S1and S2, screws that comprise an insulating material such as plastic, ceramic, etc. or that are coated with insulation are used to inhibit short circuits between each of the terminals and metal substrate228and between each of the terminals and heat sink.

Connector271is connected to connector270. With this configuration, it is possible to obtain a signal from temperature sensing element60via cable272.

Next, Variation 1 of the light source device according to the present embodiment will be described. The light source device according to the present variation has a configuration in which a terminal fixing screw or the like for fixing more firmly semiconductor light-emitting device210to heat sink219, etc. is included. Hereinafter, the configuration of the terminal fixing screw, etc. of the light source device according to the present variation will be described with reference toFIG.22AandFIG.22B.FIG.22Ais a cross-sectional view schematically illustrating the state in which terminal fixing screw Sc1is fixed to heat sink219according to the present variation.FIG.22Bis an exploded cross-sectional view illustrating the method of fixing terminal fixing screw Sc1to heat sink219according to the present variation.

According to the present variation, heat sink219includes a surface that is conductive, and comprises, for example, an aluminum alloy without surface treatment. According to the present variation, terminal213and wiring substrate220are fixed to threaded hole T1, etc. of heat sink219, using terminal fixing screw Sc1or the like that comprises iron, stainless steel, or other conductive material. In this case, washer Wi (i.e., a spacer) having a ring shape and comprising an insulating material is inserted between terminal fixing screw Sc1and terminal213, as illustrated inFIG.22AandFIG.22B. With this configuration, it is possible to inhibit short circuit between terminal213and heat sink219via terminal fixing screw Sc1. Moreover, according to the present variation, washer Wi is a flanged washer including flange WiC. By using a flanged washer, a portion of washer Wi can be placed inside the through-hole of terminal213or inside electrode through-hole237aof the wiring substrate, and thus it is possible to reduce the possibility of short circuit between terminal fixing screw Sc1and terminal213or between terminal fixing screw Sc1and first extraction electrode237inside the hole. It is possible to fix terminal214and wiring substrate220to heat sink219that comprises a metal material, with the terminal fixing screw that comprises a metal material, while inhibiting short circuit between terminal214and heat sink219in the same manner as above.

With this configuration, it is possible to more firmly fix semiconductor light-emitting device210and heat sink219, as well as closely adhere semiconductor light-emitting device210and heat sink219. As a result, it is possible to efficiently dissipate heat from semiconductor light-emitting element41of semiconductor light-emitting device210to heat sink219.

Next, a semiconductor light-emitting device according to Embodiment 3 will be described. The semiconductor light-emitting device according to the present embodiment differs from semiconductor light-emitting device210according to Embodiment 2 mainly in the direction of extraction of emitted light. The following describes the semiconductor light-emitting device according to the present embodiment focusing on the differences from semiconductor light-emitting device210according to Embodiment 2, with reference toFIG.23toFIG.25.FIG.23,FIG.24, andFIG.25are a perspective view, an exploded perspective view, and cross-sectional view, respectively, each of which schematically illustrates the overall configuration of semiconductor light-emitting device310according to the present embodiment.FIG.25illustrates a portion of the cross-section surface of semiconductor light-emitting device310taken along line XXV-XXV indicated inFIG.24. In addition, inFIG.25, semiconductor light-emitting device310in a state before cap unit350is bonded to wiring substrate220is indicated.

As illustrated inFIG.23andFIG.24, semiconductor light-emitting device310according to the present embodiment includes wiring substrate220, cap unit350, and connector270. As illustrated inFIG.24, semiconductor light-emitting device310further includes semiconductor light-emitting element41, submount45, reflective optical element358, and temperature sensing element60. As illustrated inFIG.23andFIG.25, semiconductor light-emitting device310according to the present embodiment emits emitted light L1, which has been emitted by semiconductor light-emitting element41, in the direction perpendicular to upper surface220aof wiring substrate220. Specifically, as illustrated inFIG.25, semiconductor light-emitting device310includes reflective optical element358, and emitted light L1from semiconductor light-emitting element41is reflected by reflective optical element358and propagates in the direction perpendicular to upper surface220aof wiring substrate220. More specifically, reflective surface358rof reflective optical element358is disposed at a position facing the emission surface of semiconductor light-emitting element41. Reflective surface358ris slanted at 45 degrees with respect to the optical axis of semiconductor light-emitting element41. With this configuration, emitted light L1is reflected by reflective surface358r, and propagates in the direction perpendicular to upper surface220aof wiring substrate220and away from wiring substrate220.

As illustrated inFIG.25, reflective optical element358is bonded to protection film225of opening221avia auxiliary bonding film359having a configuration equivalent to the configuration of first auxiliary bonding film255aand bonding material226.

As illustrated inFIG.24, cap unit350according to the present embodiment includes top plate351that is transparent and has a rectangular shape, and holder352. Top plate351is a light-transmissive window having a configuration equivalent to the configuration of side wall51of cap unit50according to Embodiment 2. In other words, top plate351is a light-transmissive window including an inorganic light-transmissive plate and an antireflection film disposed on the inorganic light-transmissive plate. With this configuration, emitted light L1from semiconductor light-emitting element41passes through top plate351that is the light-transmissive window. Holder352is a frame-shaped component including four side walls connected to four sides at a peripheral edge of top plate351.

According to the above-described configuration, it is possible to easily extract emitted light L1from semiconductor light-emitting element41from the upper surface of cap unit350to the outside.

Cap unit350is, for example, formed by bonding top plate351to holder352having a frame shape, by optical contact or laser bonding. As a result, top plate351and the peripheral portion of holder352are closely adhere to each other. In addition, holder352includes a surface facing top plate351and the first auxiliary bonding film (not illustrated) is disposed on the surface.

Spacer layers are each disposed between first insulating layer221and the bonding surface of cap unit350with upper surface220aof wiring substrate220, in semiconductor light-emitting device310according to the present embodiment as well. Second auxiliary bonding film255cis disposed above each of the spacer layers. As a result of bonding holder352and wiring substrate220by bonding adhesive, it is possible to seal the gap between cap unit350and wiring substrate220. With this configuration, the advantageous effects equivalent to those of semiconductor light-emitting device210according to Embodiment 2 are yielded by semiconductor light-emitting device310according to the present embodiment as well.

It should be noted that, as the configuration between cap unit350and wiring substrate220, the configuration equivalent to that of Embodiment 1 may be employed.

It should be noted that, although semiconductor light-emitting device310including a single semiconductor light-emitting element41has been described as an example in the above-described embodiment, semiconductor light-emitting device310may include a plurality of semiconductor light-emitting elements41(seeFIG.26which will be described later). In this case, the reflective optical element may be disposed at a position facing the emission surface of each of the plurality of semiconductor light-emitting elements41. The plurality of semiconductor light-emitting elements41may be arranged in an array or in a matrix.

In addition, although the reflective optical element including a reflective surface slanted at 45 degrees with respect to the optical axis has been disposed at a position facing the emission surface of semiconductor light-emitting element41according to the above-described embodiment, other optical element may be disposed. For example, a reflective optical element provided with a wavelength conversion member comprising a phosphor layer or the like disposed on a reflective mirror surface slanted at any angle greater than or equal to 10 degrees and less than or equal to 80 degrees with respect to the optical axis may be disposed. In this case, for example, a semiconductor laser element using a nitride semiconductor material with emitted light L1having a peak wavelength in the wavelength range of approximately from greater than or equal to 380 nm to less than or equal to 490 nm may be used as semiconductor light-emitting element41. With this configuration, a portion of emitted light L1emitted from semiconductor light-emitting element41is wavelength-converted by the reflective optical element, thereby making it possible to emit light including the portion of emitted light L1and the wavelength-converted light from top plate351of semiconductor light-emitting device310. More specifically, emitted light L1may be light having a wavelength in the blue region and the wavelength-converted light may be light having a wavelength in the yellow region. With this configuration, it is possible to implement a semiconductor light-emitting device which emits white light that is high in luminance and optical output from top plate351, and is highly reliable.

In addition, as the reflective optical element, a diffractive optical element or diffuse optical element may be used. With this configuration, it is possible to emit emitted light L1that has been emitted from semiconductor light-emitting element41from top plate351in a predetermined emission pattern in any direction by the reflective optical element. In this case, for example, by using emitted light L1having a wavelength in the 900 nm band, it is possible to implement semiconductor light-emitting device310that emits infrared light that is high in optical output, and is highly reliable. Such semiconductor light-emitting device310, for example, can be used for light detection and ranging (Lidar) device, etc.

Variation

Next, a semiconductor light-emitting device according to a variation of the present embodiment will be described. The semiconductor light-emitting device according to the present variation includes a plurality of semiconductor light-emitting elements. A reflective optical element is disposed at a position facing the emission surface of each of the plurality of semiconductor light-emitting elements41. The plurality of semiconductor light-emitting elements41and reflective optical elements are arranged in a matrix. Hereinafter, the configuration of the semiconductor light-emitting device according to the present variation will be described with reference toFIG.26.

FIG.26is a top view schematically illustrating the overall configuration of semiconductor light-emitting device310baccording to the present variation. It should be noted thatFIG.26illustrates the state before a cap unit is attached to wiring substrate320b, for showing the inside of the cap unit. For this reason, second auxiliary bonding film355cthat is disposed along the bonding surface of the cap unit is illustrated. The plurality of semiconductor light-emitting elements41and reflective optical elements358are arranged in a matrix of three rows and three columns according to the present variation.

Semiconductor light-emitting device310baccording to the present variation includes wiring substrate320b, a plurality of semiconductor light-emitting elements41, a plurality of submounts45, a cap unit (not illustrated inFIG.26), temperature sensing element60, and connectors371and372.

Wiring substrate320bincludes a metal substrate (not illustrated inFIG.26), first insulating layer321, first metal layers331ato331c, second metal layers332ato332c, third metal layer333, fourth metal layer334, spacer layers530ato530i, a plurality of first pad electrode331p, a plurality of second pad electrode332p, and second insulating layer322.

First insulating layer321is disposed above the metal substrate, and includes opening321aformed therein.

First metal layers331ato331care disposed above first insulating layer321, and connected to first pad electrode331pand connector371. Second metal layers332ato332care disposed above first insulating layer321, and connected to second pad electrode332pand connector372.

Third metal layer333is disposed above first insulating layer321, and connected to temperature sensing element60and connector371. Fourth metal layer334is disposed above first insulating layer321, and connected to temperature sensing element60and connector372.

Second insulating layer322is disposed above first insulating layer321, 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.

Spacer layers530ato530iare disposed between the bonding surface of the cap unit and first insulating layer321, at positions different from the positions of each of the first metal layers and each of the second metal layers. Each of the spacer layers is disposed along the bonding surface of the cap unit in the present variation as well.

According to the present variation, semiconductor light-emitting element41is mounted above submount45. The three semiconductor light-emitting elements, which are aligned in the same row (i.e., arranged in the horizontal direction ofFIG.26), are electrically connected in series by metal wire W1. First pad electrode331pand second pad electrode332pare disposed in the lateral direction of three semiconductor light-emitting elements41(horizontal direction ofFIG.26) arranged in the row direction. In other words, the plurality of semiconductor light-emitting elements41which are electrically connected in series are aligned between first pad electrode331pand second pad electrode332p. According to the present variation, three semiconductor light-emitting elements41are arranged in the row direction. Three first pad electrodes331pand three second pad electrodes332pare arranged respectively in the column direction so as to correspond to a plurality of semiconductor light-emitting element groups in three columns. First pad electrodes331pare each connected to semiconductor light-emitting element41by metal wire W2. Second pad electrodes332pare each connected to semiconductor light-emitting element41by metal wire W3. The plurality of first pad electrodes331pare each connected to connector371provided above wiring substrate320bat a facing position by a corresponding one of the plurality of first metal layers331ato331c. The plurality of second pad electrodes332pare each connected to connector372provided above wiring substrate320bat a facing position by a corresponding one of the plurality of second metal layers332ato332c.

According to the above-described configuration, it is possible to increase the optical output of the emitted light emitted from semiconductor light-emitting device310bcompared to the case where a single semiconductor light-emitting element41is used. In addition, although the heat generated in semiconductor light-emitting device410increases with increase in the optical output, it is possible, with semiconductor light-emitting device310baccording to the present variation, to efficiently discharge the heat using a heat sink or the like. As a result, it is possible to inhibit degradation of each of the semiconductor light-emitting elements. It is thus possible to implement semiconductor light-emitting device310bwhich is high in optical output and is highly reliable. Such semiconductor light-emitting device310bas described above can be used, for example, as a light source for a projector by using, as semiconductor light-emitting element41, a semiconductor laser element that emits emitted light having a wavelength in the visible light region such as blue, green, and red.

Next, a semiconductor light-emitting device according to Embodiment 4 will be described. The semiconductor light-emitting device according to the present embodiment differs from semiconductor light-emitting device10according to Embodiment 1 in that, for example, a plurality of semiconductor light-emitting elements are included. The following describes the semiconductor light-emitting device according to the present embodiment focusing on the differences from semiconductor light-emitting device10according to Embodiment 1, with reference toFIG.27.

FIG.27is a top view schematically illustrating the overall configuration of semiconductor light-emitting device410according to the present embodiment. It should be noted thatFIG.27illustrates the state before a cap unit is attached to wiring substrate420, for showing the inside of cap unit450. For this reason, second auxiliary bonding film455cthat is disposed along the bonding surface of the cap unit is illustrated.

Cap unit450, temperature sensing element60, and connector70have configurations equivalent to the configurations of cap unit50, temperature sensing element60, and connector70, according to Embodiment 1, respectively. It should be noted that cap unit450includes side wall451that is a light-transmissive window. In addition, shielding component60sincludes a configuration equivalent to the configuration of shielding component60saccording to Variation 3 of Embodiment 1. It should be noted that, according to the present embodiment, temperature sensing element60and shielding component60sare disposed inside cap unit450.

Wiring substrate420includes metal substrate428, first insulating layer421, second insulating layer422, spacer layers430a,430b,430c, and430d, first metal layer431, second metal layer432, third metal layer433, fourth metal layer434, first pad electrode431p, second pad electrode432p, and a protection film (not illustrated inFIG.27), in the same manner as wiring substrate20according to Embodiment 1. InFIG.27, spacer layers430a,430b,430c, and430d, first metal layer431, second metal layer432, third metal layer433, and fourth metal layer434are hidden under second insulation layer422, and thus indicated as dashed lines.

According to the present embodiment, in the same manner as wiring substrate20according to Embodiment 1, through-holes428aand428band positioning holes429aand429bare provided in wiring substrate420.

Opening421ais formed in first insulating layer421in the same manner as first insulating layer21according to Embodiment 1. A protection film comprising Ni, Au, or the like is formed in opening421ato form a mounting surface for mounting each semiconductor light-emitting element. According to the present embodiment, semiconductor light-emitting elements441ato441care disposed in the opening via submount445.

First metal layer431, second metal layer432, third metal layer433, fourth metal layer434, first pad electrode431p, and second pad electrode432phave the same configurations as the configurations of first metal layer431, second metal layer432, third metal layer433, fourth metal layer434, first pad electrode31p, and second pad electrode32paccording to Embodiment 1, respectively.

Spacer layers430a,430b,430c, and430daccording to the present embodiment are disposed between first insulating layer of wiring substrate420and the bonding surface of cap unit450with wiring substrate420, in the same manner as the spacer layers according to Embodiment 1. According to the present embodiment, the spacer layer is disposed at a position different from the position of each of the metal layers above first insulating layer. With this configuration, the advantageous effects equivalent to those of semiconductor light-emitting device10according to Embodiment 1 are yielded by semiconductor light-emitting device410according to the present embodiment as well.

Submount445includes an insulating block that is a rectangular parallelepiped block comprising an insulating material, first electrodes447ato447cand second electrode448each of which is a metal film disposed on the upper surface of the insulating block, and a metal film (not illustrated) disposed on the lower surface of the insulating block. First electrodes447ato447cand second electrode448are spaced apart from each other and electrically insulated. In addition, first electrodes447ato447cand second electrode448are electrically insulated from the metal film disposed on the lower surface of the insulating block. The metal films disposed on the lower surfaces of first electrodes447ato447c, second electrode448, and the insulating block are metal films that comprise Ni, Cu, Pi, Au, or the like.

Each of semiconductor light-emitting elements441ato441chas a configuration equivalent to the configuration of semiconductor light-emitting element41according to Embodiment 1. According to the present embodiment, semiconductor light-emitting elements441ato441care junction-down mounted to first electrodes447ato447c, respectively.

In addition, first pad electrode431pand first electrode447aare connected to each other via metal wire W2. The upper surface of semiconductor light-emitting element441aand first electrode447bare connected to each other via metal wire W1. The upper surface of semiconductor light-emitting element441band first electrode447care connected to each other via metal wire W1. The upper surface of semiconductor light-emitting element441cand second electrode448are connected to each other via metal wire W1. Second electrode448and second pad electrode432pare connected to each other via metal wire W3. With this configuration, semiconductor light-emitting elements441ato441ccan be connected in series. As a result, it is possible to supply the same current to each of the semiconductor light-emitting elements.

According to the above-described configuration, it is possible to increase the optical output of the emitted light emitted from semiconductor light-emitting device410compared to the case where a single semiconductor light-emitting element41is used. In addition, although the heat generated in semiconductor light-emitting device410increases with increase in the optical output, it is possible, with semiconductor light-emitting device410according to the present embodiment, to efficiently discharge the heat using a heat sink or the like. As a result, it is possible to inhibit degradation of each of the semiconductor light-emitting elements.

Although the semiconductor light-emitting device, etc. according to the present disclosure have been described based on the embodiments thus far, the present disclosure is not limited to the embodiments described above.

For example, in each of the above-described embodiments, an example in which the semiconductor light-emitting element is a semiconductor light-emitting element has been described, but the semiconductor light-emitting element is not limited to the semiconductor light-emitting element. For example, the semiconductor light-emitting element may be a superluminescent diode or a quantum cascade laser.

In addition, in each of the above-described embodiments, an example in which a metal substrate is used as the first substrate has been described, but the first substrate may be an insulating substrate. In this case, the wiring substrate need not include the first insulating layer.

In addition, in each of the above-described embodiments, a temperature sensing element has been used as an example of the functional element, but some other functional element may be used. As other functional element, it is possible to use, for example, a light-receiving element, a switching element such as a transistor, and various passive elements such as a capacitor, an inductor, and a resistor. In addition, the shape of the metal layer or pad electrode to be connected to the functional element can be arbitrarily selected according to the type, etc. of the functional element. In addition, the semiconductor light-emitting element and the functional element may be electrically connected above the wiring substrate.

In addition, although the semiconductor light-emitting device according to Variation 2 of the above-described Embodiment 2 includes shielding component60s, cap unit50may function as a shielding component when temperature sensing element60is disposed outside cap unit50. In other words, it is possible to cause cap unit50to function as a shielding component, by reducing the transmittance of light from semiconductor light-emitting element41at the side wall facing rear end surface41R of semiconductor light-emitting element41among the four side walls of cap unit50.

In addition, in each of the above-described embodiments, the semiconductor light-emitting element has been mounted on the metal substrate via the submount, but the semiconductor light-emitting element may be directly mounted without involving the submount. In this case, the semiconductor light-emitting element may be junction-up mounted above the metal substrate.

It should be noted that, in each of the above-described embodiments, a semiconductor light-emitting device that includes a cap unit has been described, but it is possible to implement a semiconductor light-emitting device that does not include a cap unit as well. The following describes such a semiconductor light-emitting device with reference toFIG.28.FIG.28is a perspective view schematically illustrating the configuration of semiconductor light-emitting device910according to a reference example.

Semiconductor light-emitting device910includes wiring substrate920, semiconductor light-emitting element41, submount45, temperature sensing element60, and connector70. Semiconductor light-emitting element41, submount45, temperature sensing element60, and connector70according to the reference example include configurations equivalent to the configurations of semiconductor light-emitting element41, submount45, temperature sensing element60, and connector70according to Embodiment 1.

Wiring substrate920matches wiring substrate20according to Embodiment 1 in the configuration other than the configuration of first insulating layer921, the configurations of third metal layer933and fourth metal layer934, and the point that a spacer layer is not provided. Opening921aof first insulating layer921extends to the end edge of wiring substrate920. In other words, opening921ahas an open shape in first insulating layer921, which is open on the side-surface side in the emission direction of emitted light L1of semiconductor light-emitting element41. Third metal layer933and fourth metal layer934have configurations equivalent to the configurations of third metal layer233and fourth metal layer234according to Embodiment 2, respectively. In addition, second insulating layer922has a configuration equivalent to the configuration of second insulating layer222according to Embodiment 2.

It is possible to implement a semiconductor light-emitting device which is high in optical output, with semiconductor light-emitting device910having the configuration not provided with a cap unit as descried above as well. Furthermore, since semiconductor light-emitting device910does not include a cap unit or a spacer layer, semiconductor light-emitting device910has a configuration more simplified than the configuration of semiconductor light-emitting device10according to Embodiment 1, and also is higher in the degree of freedom of design.

In addition, forms obtained by various modifications to the respective exemplary embodiments described above that can be conceived by a person of skill in the art as well as forms realized by arbitrarily combining structural components and functions in the respective exemplary embodiments described above which are within the scope of the essence of the present disclosure are also included in the present disclosure.

INDUSTRIAL APPLICABILITY

The semiconductor light-emitting device, etc. according to the present disclosure are applicable as, for example, a light source which is high in optical output and reliability, a laser processing machine, a vehicle lighting device such as a vehicle head light, a lighting device, a distance measuring devices such as a light detection and ranging (Lidar) device, a light source device for a projector, a medical light source device, a light source device for inspection, a light source device for sterilization, etc.