JP2013065600A - Light emitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light emitting device which improves heat radiation performance and facilitates the mounting to a lighting device and the like.SOLUTION: A light emitting device 10 has first and second protruding electrodes 26, 34, a semiconductor laser element 52, and a translucent frame part 40. A first protruding electrode is composed of a first protruding part, a first step surface 26a, and a first surface 26b, and the first step surface is formed by a first metal plate 24. A region of the first surface which includes the first protruding part in a plane view is formed by a second metal plate 20. The first protruding part is formed by a third metal plate 22 having the same composition as the second metal plate. The second protruding electrode has a second protruding part 34a and a second step surface 34b having the same composition as the first metal plate. The semiconductor laser element is provided between the first and second protruding parts. The translucent frame part encloses the first and second protruding parts and the semiconductor laser element and is bonded to the first and second step surfaces. Heat conductivity of the second metal plate is higher than that of the first metal plate.

Description

  Embodiments described herein relate generally to a light emitting device.

  In the surface-emitting light-emitting element in which electrodes are provided on the upper surface and the lower surface, part of the emitted light is shielded by the electrodes. Moreover, heat dissipation is bad and there is a limit to increase in current density. For this reason, it is necessary to use a large area chip in order to achieve high luminance.

  The surface-emitting light-emitting element has a Lambertian radiation pattern, and the full width at half maximum is as wide as 120 degrees, for example. For this reason, it is difficult to narrow the emitted light.

  On the other hand, a semiconductor laser (Semiconductor Laser, Diode Laser, Laser Diode: LD) can emit a laser beam having a sharp directivity from a light emitting region on a minute side surface. Therefore, the semiconductor laser can be applied to a linear light source. The linear light source can be used for an automobile fog lamp, a backlight light source of a display device, an optical sensor light source, and the like.

  In such an application, a light emitting device that is excellent in miniaturization, heat dissipation, and mountability and has high reliability is required.

JP 2005-333014 A

  Provided is a light-emitting device with improved heat dissipation, easy mounting on a lighting device or the like, and having high reliability.

  The light emitting device of the embodiment of the present invention includes a first convex electrode, a second convex electrode, a semiconductor laser element, and a translucent frame portion. The first convex electrode includes a first convex portion, a first step surface surrounding the first convex portion, and a first surface on a side opposite to the first step surface. Have. In the first convex electrode, the first step surface is made of a first metal plate, and a region including the first convex portion in a plan view of the first surface is made of a second metal plate. The first convex portion is made of a third metal plate which is a metal having the same composition as that of the second metal plate. The second convex electrode has a second convex portion and a second step surface surrounding the second convex portion. In the second convex electrode, the second step surface is made of a metal plate facing the first step surface of the first convex electrode and having the same composition as the composition of the first metal plate. . The semiconductor laser element is provided between the first convex portion and the second convex portion and has a light emitting layer. The translucent frame portion surrounds each of the first convex portion, the second convex portion, and the semiconductor laser element, is made of glass, and is bonded to the first step surface; The semiconductor laser element can be sealed by being bonded to the second step surface. The thermal conductivity of the second metal is higher than the thermal conductivity of the first metal plate, and the difference between the linear expansion coefficient of the first metal plate and the linear expansion coefficient of the translucent frame portion is The difference between the linear expansion coefficient of the second metal plate and the linear expansion coefficient of the translucent frame portion is smaller. Of the laser light emitted from the semiconductor laser element, the light component within the full width at half maximum can be emitted outward from the translucent frame.

  Provided is a light-emitting device with improved heat dissipation, easy mounting on a lighting device or the like, and having high reliability.

FIG. 1A is a partial schematic perspective view of the light emitting device according to the first embodiment, and FIG. 1B is a schematic cross-sectional view taken along the line AA. It is a graph explaining the far field image of a laser beam. It is a schematic cross section of the light-emitting device concerning a 1st comparative example. FIG. 4A is a schematic cross-sectional view of a light emitting device according to the second embodiment, and FIG. 2B is a schematic cross-sectional view of a modification thereof. It is a schematic cross section of the light emitting device according to the third embodiment. FIG. 6A is a schematic cross-sectional view of a light emitting device according to a fourth embodiment, and FIG. 6B is a schematic cross-sectional view of a light emitting device according to the modification. FIG. 7A is a schematic cross-sectional view of the light emitting device according to the fifth embodiment, and FIG. 7B is a schematic plan view cut along the line DD. FIG. 8A is a schematic cross-sectional view of a light emitting device according to a modification of the fifth embodiment, and FIG. 8B is a schematic plan view cut along a line DD. FIG. 9A is a schematic cross-sectional view of the light emitting device according to the sixth embodiment, and FIG. 9B is a schematic plan view cut along the line DD. FIG. 10A is a schematic cross-sectional view of a light emitting device according to a modification of the sixth embodiment, and FIG. 10B is a schematic plan view cut along the line DD. FIG. 11A is a schematic plan view of the light emitting device according to the fifth embodiment, and FIG. 11B is a schematic cross-sectional view taken along the line BB. FIG. 12A is a schematic plan view of a light emitting device according to a second comparative example, and FIG. 12B is a schematic cross-sectional view taken along the line CC. FIG. 13A is a schematic cross-sectional view of a linear illumination device using the light emitting device according to the sixth embodiment, and FIG. 13B is a schematic view of the linear illumination device using the light emitting device according to the third embodiment. It is a schematic cross section. It is a model side view of the linear illuminating device concerning a 3rd comparative example.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1A is a partial schematic perspective view of the light emitting device according to the first embodiment, and FIG. 1B is a schematic cross-sectional view taken along the line AA.
The light emitting device 10 includes a first convex electrode 26, a second convex electrode 34, a semiconductor laser element 52, and a transparent translucent frame portion 40. FIG. 1A is a schematic perspective view excluding the upper part of the second convex electrode 34.

  The first convex electrode 26 includes a second metal plate 20, a third metal plate 22 that is smaller than the second metal plate 20 when viewed from above, and the third metal plate 22 when viewed from above. And a first metal plate 24 to be a first stepped surface 26a. The first metal plate 24 is in contact with the peripheral region of the second metal plate 20 and has a thickness T3 that is smaller than both the thickness T1 of the second metal plate 20 and the thickness T2 of the third metal plate 22. Have. The thermal conductivity of the second metal plate 20 and the thermal conductivity of the third metal plate 22 are higher than the thermal conductivity of the first metal plate 24, respectively. In FIG. 1, it is assumed that the second metal plate 20 and the third metal plate 22 are the same metal and are integrated. That is, the third metal plate 22 becomes the first convex portion of the first convex electrode 26. Further, the first convex electrode 26 has a first step surface 26a composed of the first convex portion and the first metal plate 24 provided around the first convex portion, and a side opposite to the first step surface 26a. And a first surface 26b.

  A submount 50 made of ceramic or the like is provided on the third metal plate 22, and a semiconductor laser element 52 is further provided thereon.

  If the submant 50 is conductive, the bonding wire 54 can be omitted. When the submount 50 is insulative, the semiconductor laser element 52 is bonded onto the conductive layer provided on the surface of the submount 50. By connecting the conductive layer and the third metal plate 22 with a bonding wire 54, one electrode of the semiconductor laser element 52 and the first convex electrode 26 can be connected. On the other hand, the other electrode of the semiconductor laser element 52 and the second convex electrode 34 can be connected by, for example, metal bumps 56.

  A translucent frame 40 made of glass such as borosilicate is provided so as to surround the third metal plate 22 and the semiconductor laser element 52. If the thickness TF in the lateral direction of the translucent frame portion 40 is set to 0.2 mm or more, for example, the adhesive strength with the first metal plate 24 can be kept high. The second convex electrode 34 includes a fourth metal plate 30 and a fifth metal plate 32. The second convex electrode 34 includes a second convex portion 34a provided on the fourth metal plate 30, a second step surface 34b around the second convex portion 34a, and a second step. A second surface 34c on the side opposite to the surface 34b. The second step surface 34b of the second convex electrode 34 and the first step surface 26a of the first convex electrode 26 face each other with the semiconductor laser element 52 interposed therebetween. The first step surface 26a made of the first metal plate 24, the second step surface 34b made of the fifth metal plate 32, and the entire circumferences of both side end portions of the translucent frame portion 40 are bonded to each other. Then, the semiconductor laser element 52 is sealed. FIG. 1A shows a state where the fourth metal plate 30 is removed and the inside can be seen.

  In the present embodiment, the difference between the linear expansion coefficient (also referred to as thermal expansion coefficient) of the first metal plate 24 and the linear expansion coefficient of the translucent frame portion 40 is equal to the linear expansion coefficient of the second metal plate 20. It is smaller than the difference from the linear expansion coefficient of the translucent frame 40. The difference between the linear expansion coefficient of the fifth metal plate 32 and the linear expansion coefficient of the translucent frame portion 40 is the difference between the linear expansion coefficient of the fourth metal plate 30 and the linear expansion coefficient of the translucent frame portion 40. Smaller than the difference. That is, it can be said that the first and fifth metal plates are made of a sealing metal.

  The second metal plate 20 and the third metal plate 22 can be, for example, copper, copper alloy, or the like. The first metal plate 24 and the fifth metal plate 32 can be, for example, Kovar, molybdenum, iron, or the like. That is, the second metal plate 20 and the first metal plate 24 can be bonded using silver solder or the like. If it does in this way, generated heat HF can be efficiently discharged outside from radiating fin 60.

  The thermal conductivity of copper is 401 W / m · K. On the other hand, the thermal conductivity of Kovar is 17 W / m · K, which is as small as about 4.2% of copper. Molybdenum has a thermal conductivity of 138 W / m · K. Since the second metal plate 20 is attached to a heat radiating fin or the like, the thickness T1 is larger than the thickness T3 of the first metal plate 24 to increase the mechanical strength. Further, instead of copper, a copper alloy containing 2.3 wt% iron (wt%), 0.1 wt% zinc, 0.03 wt% phosphorus or the like can be used (thermal conductivity: 262 W / m · K).

The coefficient of linear expansion of Kovar is 5.7 × 10 ⁻⁶ K ⁻¹ . The linear expansion coefficient of copper is in the vicinity of 16.5 × 10 ⁻⁶ K ⁻¹ , which is as large as approximately 2.9 times that of Kovar. Further, the linear expansion coefficient of borosilicate glass is in the vicinity of 5.2 × 10 ⁻⁶ K ⁻¹ . That is, the difference between the linear expansion coefficient of Kovar and the linear expansion coefficient of borosilicate glass is smaller than the linear expansion coefficient of copper and the linear expansion coefficient of borosilicate glass. For this reason, in this embodiment, when bonding is performed using AuSn solder or AuGe solder, the occurrence of cracks or cracks in the borosilicate glass is suppressed. That is, the internal semiconductor laser element 52 can be hermetically sealed by the first convex electrode 26, the second convex electrode 34, and the translucent frame 40, and has high reliability. Can keep sex.

  If the third metal plate 22 is made of copper, the difference in linear expansion coefficient with the semiconductor laser element 52 is large. For this reason, when direct bonding is performed using a solder material or the like, stress is often generated in the semiconductor laser element 52. If a submant is provided between the semiconductor laser element 52 and the third metal plate 22, the stress applied to the semiconductor laser element 52 is reduced and the reliability can be improved.

The semiconductor laser element 10 is made of a material such as InGaAlN, InAlGaP, or GaAlAs. Note that in this specification, the InGaAlN system is represented by a composition formula of In _x Ga _y Al _1-xy N (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, x + y ≦ 1), and is an acceptor or a donor. It may contain the element which becomes. Further, it is represented by a composition formula of In _x (Al _y Ga _1-y ) _1-x P (0 ≦ x ≦ 1, 0 ≦ y ≦ 1), and may include an element serving as an acceptor or a donor. Furthermore, the AlGaAs system is expressed by a composition formula of Al _x Ga _1-x As (0 ≦ x ≦ 1) and may include an acceptor and a donor.

  Moreover, if the height of the first convex electrode 26 and the second convex electrode 34 is reduced, the height of the light emitting device 10 can be reduced. In this case, when the thicknesses of the second metal plate 20 and the third metal plate 22 are each 0.2 mm or more, it is easy to ensure the strength of the package.

FIG. 2 is a graph illustrating a far-field image of laser light.
The vertical axis represents the relative emission intensity, and the horizontal axis represents the angle (degree) from the optical axis. The far field pattern (FFP) shows the spread of the laser beam 53 emitted from the semiconductor laser element 52 (FIG. 1A) .Laser beam 53 perpendicular to the element surface of the semiconductor laser element 52 The full width at half maximum θv is approximately 30 degrees, the full width at half maximum θh in the horizontal direction is approximately 10 degrees, etc. Of this laser beam 53, the light component within the full width at half maximum is the first convex electrode 26 or the second It is preferable that the light is emitted outward from the translucent frame portion 40 without being shielded by the convex electrode 34.

  Note that the side surface of the semiconductor laser element 52 is a mirror surface that is normally a scratched surface and forms an optical resonator. For example, when the reflectance of the emission surface of the laser beam 53 is 5 to 30% and the reflectance of the reflection surface opposite to the emission surface is 90% or more, the output from the emission surface can be increased.

  If the first convex electrode 26 does not have the third metal plate 22, in the process of bonding the first metal plate 24 to the outer periphery of the second metal plate 20, The solder material may spread and it may be difficult to bond the submount 50 or the semiconductor laser element 52. If the thickness T3 of the first metal plate 24 is larger than the thickness T2 of the third metal plate 22, it is difficult to bond the semiconductor laser element 52 and the submount 50 onto the second metal plate 20. It becomes. That is, the thickness T3 of the first metal plate 24 is preferably smaller than the thickness T2 of the third metal plate 22.

  In the present embodiment, the light component within the full width at half maximum of the laser beam 53 is emitted from the translucent frame 40 to the outside without being blocked by the first and second convex electrodes 26 and 34. The cross-sectional shapes of the first convex electrode 26 and the second convex electrode 34 can be determined. For example, as shown in FIG. 2, the light-shielded component (broken line) S in the measured FFP may be in a range outside the full width at half maximum. Similarly, the cross-sectional shape of the second convex electrode 34 can be determined so as not to block light components within the full width at half maximum.

  In the case of bonding with borosilicate glass using a solder material such as AuSn, the adhesive strength is ensured by setting the thickness T3 of the first metal plate 24 to 0.05 to 0.1 mm.

  The fourth metal plate 30 and the fifth metal plate 32 can have an integrated structure made of Kovar. Further, when the fourth metal plate 30 is made of copper, the fifth metal plate 32 can be made of Kovar or the like. When electrical connection is made between the upper electrode of the semiconductor laser element 52 and the second convex electrode 34 using, for example, bumps 56, the generated heat passes through the second convex electrode 34 and is also discharged to the outside from above. Is possible. In this case, the fourth metal plate 30 is preferably made of copper or the like.

  In plan view, the light emitting device 10 may be a cylinder, an elliptical column, a polygonal column, or the like instead of a prismatic type. In the case of a cylinder, the first metal plate 24 and the fifth metal plate 32 are ring-shaped.

FIG. 3 is a schematic cross-sectional view of a light emitting device according to a first comparative example.
The first convex electrode 126 and the second convex electrode 134 are made of, for example, Kovar. Kovar having a small difference between the coefficient of linear expansion of Kovar and the coefficient of linear expansion of borosilicate glass is used as the first and second convex electrodes 126 and 134. In this case, since the thermal conductivity of Kovar is lower than that of copper or copper alloy, heat radiation becomes insufficient, and the light output and reliability may be lowered.

FIG. 4A is a schematic cross-sectional view of a light emitting device according to the second embodiment, and FIG. 2B is a schematic cross-sectional view of a modification thereof.
When the semiconductor laser element 52 is an InGaAlN material, the laser beam 53 can have a wavelength of, for example, blue to blue violet. As shown in FIG. 4A, when the yellow phosphor layer 70 is provided in a region where the laser beam 53 is transmitted in the outer edge 40b of the translucent frame portion 40, pseudo white light can be emitted. Or you may provide the yellow fluorescent substance layer 70 in the area | region which the laser beam 53 permeate | transmits among the inner edges 40a of the translucent frame part 40 like FIG.4 (b). In addition, after providing the translucent frame part 40, you may provide the transparent resin in which the fluorescent substance particle was mixed inside.

FIG. 5 is a schematic cross-sectional view of a light emitting device according to the third embodiment.
The translucent frame portion 41 on the side from which the laser beam 53 is emitted has a protruding portion 41 a that extends outward from the outer edge in the side surface direction of the first and second convex electrodes 26 and 34. If it does in this way, the light guide 72 in which the recessed part was provided, and the protrusion part 41a can be fitted together, and a linear illuminating device can be comprised. Since the light density on the surface of the protrusion 41a is reduced, deterioration due to light irradiation is suppressed even if the light guide 72 is a resin. In this case, if the phosphor layer is not provided in the light emitting device 10 and the phosphor layer 74 is provided in the light guide 72, the mixed light can be emitted to the outside.

FIG. 6A is a schematic cross-sectional view of a light emitting device according to a fourth embodiment, and FIG. 6B is a schematic cross-sectional view of a light emitting device according to the modification.
The first convex electrode 26 includes a second metal plate 20, a third metal plate 22 smaller than the second metal plate 20 as viewed from above, and the second metal plate 20 and the third metal plate 22. And a first metal plate 25 sandwiched therebetween. The thermal conductivity of the second metal plate 20 and the thermal conductivity of the third metal plate 22 are higher than the thermal conductivity of the first metal plate 25, respectively.

  In FIG. 6A, the first convex electrode 26 has a stripe shape, and the second metal plate 20 made of copper or the like is cooled to the first metal plate 25 made of a sealing metal such as Kovar. A clad metal structure embedded by hot rolling can be used. Below the semiconductor laser element 52, the thickness T3 of the first metal plate 25 made of Kovar is made thinner, for example, 0.05 to 0.1 mm, and the width W1 of the copper stripe is made smaller than the width W2 of the third metal plate 22. If it is widened, the heat generated in the vicinity of the light emitting layer of the semiconductor laser element 52 can be efficiently discharged to the radiation fins 60. In this case, if the thickness T3 of the first metal plate 25 is smaller than the thickness T1 of the second metal plate 20 and the thickness T2 of the third metal plate 22, the generated heat can be more effectively discharged. It becomes. That is, the third metal plate 22 becomes a convex portion of the first convex electrode 26. The 1st convex electrode 26 has the 1st level | step difference surface 26a which is the surface of the 1st metal plate 24 which protruded from the convex part. The first surface 26 b of the first convex electrode 26 on the side opposite to the first step surface 26 a is a second metal plate 20 and a first metal surrounding the second metal plate 20. Plate 25. In this case, let the 2nd metal plate 20 be an area | region containing a convex part (3rd metal plate 22) by planar view. In addition, a convex part and the 2nd metal plate 20 may overlap by planar view.

  In the modification of the fourth embodiment shown in FIG. 6B, the translucent frame 41 on the side from which the laser beam 53 is emitted is the outer edge in the lateral direction of the first and second convex electrodes 26, 34. It has the protrusion part 41a which protruded outward rather than. If it does in this way, the light guide provided with the recessed part and the protrusion 41a can be fitted together, and the laser beam can be emitted to the outside. Since the light density on the surface of the protrusion 41a is reduced, deterioration is suppressed even if the light guide is a resin.

  The first metal plate 25 may be provided so as to cover the entire surface of the second metal plate 20. In this case, if the thickness T3 of the first metal plate 25 is smaller than the thickness T1 of the second metal plate 20 and the thickness T2 of the third metal plate 22, the generated heat can be more effectively discharged. It becomes.

FIG. 7A is a schematic cross-sectional view of the light emitting device according to the fifth embodiment, and FIG. 7B is a schematic plan view cut along the line DD.
The first convex electrode 26 includes a second metal plate 20 and a third metal plate 22 smaller than the second metal plate 20, and is made of copper or the like. The first metal plate 24 has an opening. The second metal plate 20 is inserted into the opening of the first metal plate 24. That is, the first convex electrode 26 includes a first step surface 26a surface around the convex portion. The first surface 26 b of the first convex electrode 26 is a flat surface including the second metal plate 20 and the first metal plate 24 surrounding the second metal plate 20. In plan view, second metal plate 20 includes a convex portion. The second convex electrode 34 is made of a sealing metal and has a convex portion 34a. The translucent frame 40 is bonded to the first step surface 26 a of the first convex electrode 26 and the second step surface 34 b of the second convex electrode 34.

FIG. 8A is a schematic cross-sectional view of a light emitting device according to a modification of the fifth embodiment, and FIG. 8B is a schematic plan view cut along a line DD.
The second metal plate 20 and the third metal plate 22 may be an integrated prism. In this case, the second metal plate 20 and the third metal plate 22 have the same size.

FIG. 9A is a schematic cross-sectional view of the light emitting device according to the sixth embodiment, and FIG. 9B is a schematic plan view cut along the line DD.
The first convex electrode 26 is the same as that of the fifth embodiment. The second convex electrode 34 has substantially the same configuration as the first convex electrode 26. That is, the 4th metal plate 30 has the convex part 30b and the insertion part 30a, and has the integral structure which consists of the same metal. Further, the periphery of the insertion part 30a is a fifth metal plate 32 made of a sealing metal. This makes it easier to dissipate heat in the vertical direction.

FIG. 10A is a schematic cross-sectional view of a light emitting device according to a modification of the sixth embodiment, and FIG. 10B is a schematic plan view cut along the line DD.
The second metal plate 20 and the third metal plate 22 may be prismatic.

FIG. 11A is a schematic plan view of the light emitting device according to the fifth embodiment, and FIG. 11B is a schematic cross-sectional view taken along the line BB.
For example, two screw holes are provided in the second metal layer 21 in a direction orthogonal to the laser beam 53. If one of the screw holes has a slit shape, for example, the mounting is easy. Further, if the heat radiating fin 60 has the concave portion 60a, the first convex electrode 26 can be fitted. For this reason, it becomes easy to attach the light emitting device 10 to the heat radiating fins 60 with high accuracy and to suppress the optical axis deviation.

FIG. 12A is a schematic plan view of a light emitting device according to a second comparative example, and FIG. 12B is a schematic cross-sectional view taken along the line CC.
When the light emitting device 110 and the heat radiation fin 160 are bonded to each other with the solder material 164, it is difficult to accurately attach the light emitting device 110 to the heat radiation fin 160. For this reason, it becomes easy to produce optical axis shift.

FIG. 13A is a schematic cross-sectional view of a linear illumination device using the light emitting device according to the sixth embodiment, and FIG. 13B is a schematic view of the linear illumination device using the light emitting device according to the third embodiment. It is a schematic cross section.
In FIG. 13A, the light emitting device 10 according to the sixth embodiment has a bending mirror 76 at the tip of the protruding portion 41 a of the translucent frame portion 41. Moreover, the 2nd metal layer 20, the 3rd metal layer 22, and the 4th metal layer 34 shall consist of copper. A radiation fin 60a is attached to the first convex electrode 26, and the generated heat HF1 is discharged to the outside. In addition, a radiation fin 60b is attached to the second convex electrode 34 and the generated heat HF2 is discharged to the outside. The linear illumination device 5 includes two light emitting devices 10, a light guide 72, and a phosphor layer 78 provided on the exit surface of the light guide 72. Laser light 53 enters the light guide 78 and irradiates the phosphor layer 78 on the opposite exit surface.

  On the other hand, in the linear illumination device 5 shown in FIG. 13B, the second light guide 73 provided with the bending mirror 74 is provided between the light guide 72 and the protruding portion 41 a of the light emitting device 10. Provided. Although a slight gap between the protrusion 41a and the second light guide 73 causes a light loss of about 6%, the heat dissipation is good as in the structure of FIG.

FIG. 14 is a schematic side view of a linear illumination device according to a comparative example.
The light emitting device 110 is a CAN type semiconductor laser device. Since the heat radiation of the CAN package is performed through a thin lead, the heat radiation property is insufficient. Further, the distance between the two light emitting devices 160 is narrow, and the heat radiation fins 160 are provided only on the opposite side of the light guide 172. For this reason, heat dissipation is insufficient.

  According to the first to sixth embodiments, a light emitting device with improved heat dissipation and easy sealing is provided. Further, the structure of this embodiment can be easily downsized. Such a light-emitting device can be widely applied to linear illumination devices, planar illumination devices, display devices, and the like.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 10 Light-emitting device, 20, 21 2nd metal plate, 22 3rd metal plate, 24, 25 1st metal plate, 26 1st convex electrode, 26a 1st level | step difference surface, 26b 1st surface, 30 4th metal plate, 32 5th metal plate, 34 2nd convex electrode, 34b 2nd level | step difference surface, 34c 2nd surface, 40, 41 Translucent frame part, 41a Protrusion part, 52 Semiconductor Laser element, 53 laser beam, Θv vertical full width at half maximum, Θh horizontal full width at half maximum, T1 thickness of second metal plate, T2 thickness of third metal plate, thickness of T3 first metal plate

Claims (8)

A first convex electrode having a first convex portion, a first step surface surrounding the first convex portion, and a first surface opposite to the first step surface. The first step surface is made of a first metal plate, and the region of the first surface including the first convex portion in plan view is made of a second metal plate, The first convex electrode made of a third metal plate that is a metal having the same composition as the composition of the second metal plate,
A second convex electrode having a second convex portion and a second step surface surrounding the second convex portion, wherein the second step surface is the first convex electrode. A second convex electrode made of a metal plate facing the first step surface and having the same composition as that of the first metal plate,
A semiconductor laser element provided between the first convex portion and the second convex portion and having a light emitting layer;
A light-transmitting frame portion made of glass, surrounding each of the first convex portion, the second convex portion, and the semiconductor laser element, and bonded to the first step surface; A translucent frame portion capable of sealing the semiconductor laser element by being bonded to the second step surface;
With
The thermal conductivity of the second metal plate is higher than the thermal conductivity of the first metal plate,
The difference between the linear expansion coefficient of the first metal plate and the linear expansion coefficient of the translucent frame portion is the difference between the linear expansion coefficient of the second metal plate and the linear expansion coefficient of the translucent frame portion. Smaller than
Of the laser light emitted from the semiconductor laser element, the light component within the full width at half maximum can be emitted outward from the translucent frame. The first surface of the first convex electrode is composed of the second metal plate,
The light emitting device according to claim 1, wherein the first convex portion is continuous with the second metal plate. The first metal plate has an opening,
The second metal plate is inserted into the opening,
The light emitting device according to claim 1, wherein the first surface is a flat surface including the first metal plate and the second metal plate.   2. The light emitting device according to claim 1, wherein the first metal plate of the first convex electrode is provided between the second metal plate and the third metal plate.   The light emitting device according to claim 4, wherein the first metal plate is provided so as to further cover a side surface of the second metal plate.   The light-emitting device according to claim 1, wherein the translucent frame portion has a protruding portion on a side on which the laser light propagates.   The light emitting device according to claim 6, further comprising a bending mirror provided on the projecting portion and capable of changing a propagation direction of the laser light. The first metal plate is made of any of Kovar, iron, and molybdenum,
The light emitting device according to claim 1, wherein the second metal plate is made of either copper or a copper alloy.

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