WO2020044882A1

WO2020044882A1 - Semiconductor laser device

Info

Publication number: WO2020044882A1
Application number: PCT/JP2019/028874
Authority: WO
Inventors: 信一郎能崎; 真生川口
Original assignee: パナソニック株式会社
Priority date: 2018-08-29
Filing date: 2019-07-23
Publication date: 2020-03-05

Abstract

A semiconductor laser device (1) according to the present invention is provided with a semiconductor laser element (10) which emits laser light, a first metal member (20) which is arranged on the n-side of the semiconductor laser element (10), a second metal member (40) which is arranged on the p-side of the semiconductor laser element (10), and a first cooling member (30) which is connected to the first metal member (20); and the first cooling member (30) has a first projection part (30a) which protrudes from the front end face of the semiconductor laser element (10).

Description

Semiconductor laser device

The present disclosure relates to a semiconductor laser device having a semiconductor laser element.

This application was filed in FY2016 by the New Energy and Industrial Technology Development Organization “High-brightness, high-efficiency next-generation laser technology development / new light source / element technology development for next-generation processing / high-efficiency processing Development of GaN-based semiconductor laser with high power and high beam quality ”is a patent application subject to commissioned research and the application of Article 17 of the Industrial Technology Enhancement Law.

Since semiconductor laser devices have advantages such as long life, high efficiency, and small size, they are used as light sources in various fields such as optical disks, displays, vehicle-mounted headlamps, lighting, and laser processing devices. Above all, a semiconductor laser element used for a projector or a laser processing apparatus is required to have a high optical output exceeding 1 watt.

However, in a high-power semiconductor laser device, the current flowing through the semiconductor laser device increases. As a result, the amount of heat generated by the semiconductor laser element increases, the temperature of the semiconductor laser element increases, and the output of laser light decreases.

Therefore, conventionally, in order to enhance the heat dissipation of the semiconductor laser device, a technique of providing a cooling mechanism on both the upper side and the lower side of the semiconductor laser device has been proposed (for example, Patent Document 1). FIG. 16 is a diagram showing a semiconductor laser device 100 disclosed in Patent Document 1.

As shown in FIG. 16, a semiconductor laser device 100 disclosed in Patent Document 1 has a semiconductor laser element 110, a heat spreader 120 disposed on the semiconductor laser element 110, and fixed to an upper surface of the heat spreader 120. The semiconductor device includes a Peltier device 130, a heat spreader 140 disposed below the semiconductor laser device 110, and a Peltier device 150 fixed to a lower surface of the heat spreader 140.

JP-A-2002-353551

However, in the semiconductor laser device 100 disclosed in Patent Document 1, the Peltier

elements

130 and 150 as cooling members are disposed at positions retracted from the front end surface of the semiconductor laser element 110. For this reason, the heat diffusion cross-sectional area of the cooling member near the front end face of the semiconductor laser element 110 becomes narrow, and the heat near the front end face of the semiconductor laser element 110 cannot be efficiently radiated. As a result, the temperature in the vicinity of the front end face of the semiconductor laser device 110 increases, and the optical output decreases and the reliability decreases. As described above, in the semiconductor laser device 100 disclosed in Patent Document 1, the semiconductor laser element cannot be sufficiently cooled.

In particular, in the case where a semiconductor laser element in which a plurality of semiconductor laser chips are arranged or a semiconductor laser chip having a plurality of emitters is used as a semiconductor laser element for increasing the output, Patent Document 1 discloses the technique. In the semiconductor laser device 100, heat generated by the semiconductor laser element cannot be efficiently dissipated.

The present disclosure has been made in order to solve such a problem, and even when a high-power semiconductor laser element is used, a semiconductor laser that can efficiently radiate heat generated in the semiconductor laser element It is intended to provide a device.

In order to achieve the above object, one aspect of a semiconductor laser device according to the present disclosure is a semiconductor laser device that emits a laser beam, a first metal member disposed on an n side of the semiconductor laser device, and a semiconductor laser device. A second metal member disposed on the p-side of the device; and a first cooling member connected to the first metal member, wherein the first cooling member protrudes from a front end surface of the semiconductor laser device. It has a protrusion.

According to the semiconductor laser device according to the present disclosure, even when a high-power semiconductor laser device is used, heat generated by the semiconductor laser device can be efficiently radiated.

FIG. 1 is a perspective view of the semiconductor laser device according to the first embodiment. FIG. 2 is a top view of the semiconductor laser device according to the first embodiment. FIG. 3 is a cross-sectional view of the semiconductor laser device according to the first embodiment along line III-III in FIG. FIG. 4 is a perspective view showing a state where the first metal member and the first cooling member are removed from the semiconductor laser device according to the first embodiment. FIG. 5 is an enlarged view of a region V surrounded by a broken line in FIG. FIG. 6 is an enlarged cross-sectional view around the front part of the semiconductor laser device in the semiconductor laser device according to the first embodiment. FIG. 7 is an enlarged sectional view of the semiconductor laser device according to the first embodiment. FIG. 8 is a perspective view of the semiconductor laser device according to the second embodiment. FIG. 9 is a sectional view of the semiconductor laser device according to the second embodiment. FIG. 10 is an enlarged cross-sectional view around the front part of the semiconductor laser device in the semiconductor laser device according to the second embodiment. FIG. 11 is a perspective view of the semiconductor laser device according to the third embodiment. FIG. 12 is a sectional view of the semiconductor laser device according to the third embodiment. FIG. 13 is an enlarged cross-sectional view around the front part of the semiconductor laser element in the semiconductor laser device according to the third embodiment. FIG. 14 is a perspective view of a semiconductor laser device according to a modification of the third embodiment. FIG. 15 is an enlarged sectional view of a semiconductor laser device according to a modification of the third embodiment. FIG. 16 is a diagram illustrating a semiconductor laser device disclosed in Patent Document 1.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Each of the embodiments described below shows a specific example of the present disclosure. Therefore, numerical values, shapes, materials, constituent elements, arrangement positions of constituent elements, connection forms, and the like shown in the following embodiments are merely examples and do not limit the present disclosure. Therefore, among the components in the following embodiments, components that are not described in the independent claims that indicate the highest concept of the present disclosure are described as arbitrary components.

図 Each drawing is a schematic diagram, and is not necessarily strictly illustrated. Therefore, the scale and the like do not always match in each figure. In each of the drawings, substantially the same components are denoted by the same reference numerals, and redundant description will be omitted or simplified.

In addition, in this specification and the drawings, the X axis, the Y axis, and the Z axis represent three axes of a three-dimensional rectangular coordinate system. Therefore, the X axis and the Y axis are axes orthogonal to each other and both are orthogonal to the Z axis.

(Embodiment 1)
First, the configuration of the semiconductor laser device 1 according to the first embodiment will be described with reference to FIGS. FIG. 1 is a perspective view of a semiconductor laser device 1 according to the first embodiment. FIG. 2 is a top view of the semiconductor laser device 1. FIG. 3 is a cross-sectional view of the semiconductor laser device 1 taken along line III-III in FIG. FIG. 4 is a perspective view showing the semiconductor laser device 1 with the first metal member 20 and the first cooling member 30 removed. FIG. 5 is an enlarged view of a region V surrounded by a broken line in FIG. FIG. 6 is an enlarged cross-sectional view around the front part of the semiconductor laser element 10 in the semiconductor laser device 1.

As shown in FIGS. 1 to 3, the semiconductor laser device 1 includes a semiconductor laser element 10 for emitting laser light, a first metal member 20 and a first cooling member 30 arranged on one side of the semiconductor laser element 10. , A second metal member 40 and a second cooling member 50 arranged on the other side of the semiconductor laser device 10, and a spacer 60.

In the present embodiment, the first metal member 20 and the first cooling member 30 are heat radiation structures disposed on the n-side (n-type semiconductor layer side) of the semiconductor laser device 10. Further, the second metal member 40 and the second cooling member 50 are heat dissipation structures disposed on the p-side (p-type semiconductor layer side) of the semiconductor laser device 10.

The semiconductor laser element 10 is an LD (laser diode) chip. In the present embodiment, the semiconductor laser element 10 is a high-output type semiconductor laser chip, and has, for example, a multi-emitter structure having a plurality of emitters (light emitting points).

Specifically, as shown in FIG. 6, the semiconductor laser device 10 emits a laser beam on one surface of a semiconductor substrate 11 such as a GaN substrate, the n-type semiconductor layer 12 being a first cladding layer. In this configuration, a light emitting layer 13 (active layer) and a p-type semiconductor layer 14 as a second clad layer having a plurality of ridge portions are sequentially formed. On each ridge of the p-type semiconductor layer 14, a contact layer 15 and a p-side electrode 16 are formed. An n-side electrode 17 is formed on the other surface of the semiconductor substrate 11. The n-type semiconductor layer 12, the light emitting layer 13, and the p-type semiconductor layer 14 constitute an optical waveguide. The p-side electrode 16 and the n-side electrode 17 are electrodes for passing a current through the light emitting layer 13. In the present embodiment, the semiconductor laser device 10 has a double-sided electrode structure in which the p-side electrode 16 and the n-side electrode 17 are located on different surfaces of the semiconductor substrate 11. Although not shown, an insulating layer (current blocking layer) made of SiO ₂ or the like is formed on portions (flat portions and side surfaces of the ridge portion) other than the upper surface of the ridge portion of the p-type semiconductor layer 14. The wavelength range of the laser light emitted from the semiconductor laser device 10 is not particularly limited, but is in a range from blue-violet to infrared. As an example, the semiconductor laser device 10 emits blue laser light.

(4) The semiconductor laser device 10 is disposed on the second metal member 40 as shown in FIGS. Specifically, it is mounted on a submount 70 arranged in a concave portion 40 a provided in the second metal member 40.

In the present embodiment, the semiconductor laser device 10 is mounted on the submount 70 by junction-down mounting. That is, the semiconductor laser device 10 is mounted such that the light emitting layer 13 of the light emitting layer 13 and the semiconductor substrate 11 of the semiconductor laser device 10 is located on the second metal member 40 side. Specifically, the semiconductor laser device 10 is mounted such that the p-side electrode 16 of the p-side electrode 16 and the n-side electrode 17 is located on the second metal member 40 side.

The submount 70 has a main body 71 and a metal layer 72 formed on the surface of the main body 71. The main body 71 is made of a material having a higher thermal conductivity than the second metal member 40. The main body 71 may be either insulating or conductive. Specifically, the main body 71 is made of single-crystal diamond, polycrystalline diamond, single-crystal silicon carbide (SiC), polycrystalline silicon carbide (SiC), aluminum nitride (AlN), copper diamond, silver diamond, copper tungsten ( It is made of a laminated material such as CuW) or copper / AlN / copper, but is not limited thereto. The metal layer 72 is made of a conductive material such as a metal material. As an example, the metal layer 72 is an Au thin film layer made of gold. The shape of the submount 70 is a substantially rectangular parallelepiped. Specifically, the submount 70 has a rectangular plate shape.

The semiconductor laser device 10 mounted on the submount 70 is sandwiched between the first metal member 20 and the second metal member 40. That is, the semiconductor laser device 10 is located between the first metal member 20 and the second metal member 40. Further, the semiconductor laser device 10 is electrically connected to each of the first metal member 20 and the second metal member 40.

As shown in FIGS. 3 to 6, the semiconductor laser element 10 and the first metal member 20 are joined by a first joining member 81 made of a solder material, a ductile metal or the like. Specifically, the first bonding member 81 is inserted between the n-side electrode 17 of the semiconductor laser device 10 and the first metal member 20. Thus, the n-side electrode 17 of the semiconductor laser device 10 and the first metal member 20 are electrically connected. Note that a conductive member other than the first bonding member 81 may exist between the semiconductor laser element 10 and the first metal member 20.

As shown in FIG. 6, the semiconductor laser device 10 and the submount 70 are joined by a second joining member 82 made of AuSn or the like and made of a solder material. Specifically, the p-side electrode 16 of the semiconductor laser device 10 and the metal layer 72 of the submount 70 are joined by the second joining member 82. Thus, not only is the semiconductor laser device 10 and the submount 70 fixed, but also the p-side electrode 16 of the semiconductor laser device 10 and the metal layer 72 of the submount 70 are electrically connected. Note that a conductive member other than the second bonding member 82 may exist between the semiconductor laser element 10 and the second metal member 40.

Although not shown, when the submount 70 is insulative, the submount 70 and the second metal member 40 are electrically connected by a gold wire or a solder material. Thus, the p-side electrode 16 of the semiconductor laser device 10 and the second metal member 40 can be electrically connected via the submount 70. For example, when connecting the submount 70 and the second metal member 40 with a gold wire, the metal layer 72 of the submount 70 and the recess 40a of the second metal member 40 may be wire-bonded with the gold wire.

The semiconductor laser element 10 is disposed on the submount 70 such that the front end face, which is the laser light emission side end face, is flush with the front end face of the submount 70, but the front end face of the semiconductor laser element 10 is , May protrude from the front end face of the submount 70 or may recede from the front end face of the submount 70. However, by protruding the front end face of the semiconductor laser element 10 from the front end face of the submount 70, it is possible to suppress the laser light emitted from the semiconductor laser element 10 from being blocked (reflected) by the submount 70.

The first metal member 20 and the second metal member 40 are radiators (heat sinks) for dissipating heat generated in the semiconductor laser element 10, and are conductive members forming a current path through which a current supplied to the semiconductor laser element 10 flows. Body. Therefore, the first metal member 20 and the second metal member 40 are preferably made of a metal material having excellent heat conductivity. In the present embodiment, first metal member 20 and second metal member 40 are made of copper. Specifically, the first metal member 20 and the second metal member 40 are copper blocks. The surface of the copper block may be plated with gold.

(3) As shown in FIG. 3, the front end face of the first metal member 20 and the front end face of the second metal member 40 are flush. Further, as shown in FIG. 2, the side end surface of the first metal member 20 and the side end surface of the second metal member 40 are also flush. The front end face of the semiconductor laser device 10 and the front end face of the submount 70 are flush with the front end face of the first metal member 20 and the front end face of the second metal member 40.

第 As shown in FIGS. 1 to 5, the first metal member 20 is arranged on the n side of the semiconductor laser device 10. Specifically, the first metal member 20 is arranged so as to face the n-side electrode 17 of the semiconductor laser device 10. In the present embodiment, the first metal member 20 is disposed above the semiconductor laser device 10. As shown in FIG. 2, a first electrode terminal 21 for supplying power to the first metal member 20 is provided at a rear end of the first metal member 20. For example, a power supply line is connected to the first electrode terminal 21. At this time, since the distance between the electrode terminal 21 and the first cooling member 30 is shorter than the distance between the first electrode terminal 21 and the semiconductor laser device 10, the heat generated due to the contact resistance at the first electrode terminal 21 is less. It does not reach the semiconductor laser device 10.

第 As shown in FIGS. 1 to 5, the second metal member 40 is arranged at a position facing the first metal member 20. The second metal member 40 is arranged on the p side of the semiconductor laser device 10. Specifically, the second metal member 40 is arranged so as to face the p-side electrode 16 of the semiconductor laser device 10. In the present embodiment, the second metal member 40 is disposed below the semiconductor laser device 10. As shown in FIG. 2, a second electrode terminal 41 for supplying power to the second metal member 40 is provided at a rear end of the second metal member 40. For example, a power supply line is connected to the second electrode terminal 41.

As described above, the second metal member 40 has the concave portion 40a on the surface facing the first metal member 20. In the present embodiment, the concave portion 40a is a concave portion having a shape in which a part of the surface of the second metal member 40 is thinned and dented, and is formed at a central portion on one end side of the upper surface of the second metal member 40. I have. As an example, the concave portion 40a is a concave portion having a rectangular shape in plan view and a constant depth. Note that the bottom surface of the concave portion 40a is a flat surface.

(4) A submount 70 on which the semiconductor laser device 10 is mounted is joined to the bottom surface of the concave portion 40a. That is, the surface of the submount 70 opposite to the surface to which the semiconductor laser element 10 is bonded faces the bottom surface of the concave portion 40a.

{Circle around (4)} After the submount 70 on which the semiconductor laser element 10 is mounted is joined to the recess 40a, the first metal member 20 is overlaid on the second metal member 40 so as to cover the second metal member 40.

At this time, the first metal member 20 and the second metal member 40 are overlapped with the spacer 60 interposed therebetween. The spacer 60 is an insulator that insulates and separates the first metal member 20 and the second metal member 40. As shown in FIG. 4, the spacer 60 is, for example, a rectangular insulating sheet, and is disposed on the surface of the second metal member 40 so as to avoid the recess 40 a of the second metal member 40. The first metal member 20 and the second metal member 40 that are overlapped with the spacer 60 interposed therebetween are fixed by, for example, bolts (not shown). Therefore, the spacer 60 is pressed by the first metal member 20 and the second metal member 40.

The first metal member 20 and the second metal member 40 sandwiching the semiconductor laser element 10 are sandwiched between the first cooling member 30 and the second cooling member 50. The first cooling member 30 and the second cooling member 50 are coolers for cooling the first metal member 20 and the second metal member 40.

The first cooling member 30 has a portion arranged on the n-side of the semiconductor laser device 10. Specifically, the first cooling member 30 has a portion arranged on the n-side electrode 17 side of the semiconductor laser device 10. More specifically, the first cooling member 30 has a portion disposed on the first metal member 20, and is connected to the first metal member 20.

As shown in FIGS. 1 to 3, in the present embodiment, the first cooling member 30 has a first heat transport body 31, a heat absorber 32, and a waste heat body 33.

The first heat transporter 31 transports the heat absorbed by the heat absorber 32 to the heat exchanger 33. Specifically, as shown in FIG. 3, the first heat transport body 31 has a hollow body 31a and a heat transport liquid 31b sealed in the hollow body 31a. In the present embodiment, the first heat transport body 31 is a heat pipe. Specifically, the first heat transport body 31 has, as the hollow body 31a, a sealed long pipe (such as a copper pipe) made of a metal material or the like, and water or alternative fluorocarbon as the heat transport liquid 31b. And the like. In the present embodiment, the first heat transport body 31 (heat pipe) is bent in an L shape.

(4) The heat absorber 32 is a heat absorbing member that absorbs heat from the first metal member 20. As an example, the heat absorber 32 is made of metal. The heat absorber 32 is arranged on the first metal member 20 and is connected to the first metal member 20. Specifically, the heat absorber 32 and the first metal member 20 are in surface contact. The heat absorber 32 is provided at one end of the first heat transport body 31. Specifically, the heat absorber 32 is provided so as to cover one end of the first heat transporter 31.

(4) The heat-dissipating body 33 is a heat-discharging member that absorbs the heat absorbed by the heat-absorbing body 32 and discharges the heat transported by the first heat transport body 31 to the outside. As an example, the heat discharging body 33 is made of metal. The heat discharging body 33 is provided at the other end of the first heat transporting body 31. Specifically, the exhaust heat body 33 is provided so as to cover the other end of the first heat transport body 31. In the present embodiment, the heat discharging body 33 is physically connected to the second metal member 40, but is electrically insulated from the second metal member 40. For example, an insulating sheet or grease is inserted between the heat discharging body 33 and the second metal member 40.

The semiconductor laser device 1 configured as described above emits a laser beam when connected to an external power supply. In this case, power is supplied to the first electrode terminal 21 of the first metal member 20 and the second electrode terminal 41 of the second metal member 40 via a power supply line. Thereby, a current flows through the semiconductor laser device 1. Specifically, the flow flows in the order of the second metal member 40 → the submount 70 (metal layer 72) → the semiconductor laser device 10 → the first metal member 20. At this time, the semiconductor laser device 10 generates heat. In particular, in the semiconductor laser element 10, the temperature at the front end face from which the laser light is emitted is higher than that at the rear end face.

Therefore, in the semiconductor laser device 1 according to the present embodiment, the first cooling member 30 has the first protrusion 30a protruding from the front end surface of the semiconductor laser device 10. Further, the first protruding portion 30 a also protrudes from the front end surface of the first metal member 20. That is, the first cooling member 30 has a structure protruding from the semiconductor laser element 10 and the first metal member 20.

As described above, the first cooling member 30 is connected to the first metal member 20 arranged on the n-side of the semiconductor laser device 10, and the first projection protruding from the front end surface of the semiconductor laser device 10 to the first cooling member 30. By providing 30a, the heat diffusion cross-sectional area of heat generated near the front end face of semiconductor laser device 10 can be increased. Thereby, the heat in the vicinity of the front end face of the semiconductor laser device 10 can be efficiently radiated, so that the temperature of the entire semiconductor laser device 10 can be reduced. As a result, it is possible to suppress a decrease in the optical output of the semiconductor laser device 10 and a decrease in the reliability. Therefore, device characteristics of the semiconductor laser device 10 can be improved.

In particular, in the semiconductor laser device 1 according to the present embodiment, even when a high-output type semiconductor laser device 10 is used, heat generated in the semiconductor laser device 10 can be effectively radiated. .

In the first cooling member 30 according to the present embodiment, the distal end of one end of the first heat transport body 31 and the distal end of the heat absorber 32 are included in the first protrusion 30a. That is, the tip of one end of the first heat transport body 31 and the tip of the heat absorber 32 project from the front end face of the semiconductor laser device 10.

As a result, the first cooling member 30 has a first heat transport body 31 having substantially a cooling function and a distal end portion of a heat absorbing body 32 having substantially a function of absorbing heat of the first metal member 20, and is connected to the semiconductor laser device. 10 can protrude from the front end surface. Therefore, heat near the front end face of the semiconductor laser device 10 can be more efficiently radiated.

On the other hand, the second cooling member 50 has a portion arranged on the p side of the semiconductor laser device 10. Specifically, the entire second cooling member 50 is arranged on the p-side electrode 16 side of the semiconductor laser device 10. More specifically, the second cooling member 50 is arranged below the second metal member 40 and is connected to the second metal member 40.

In the present embodiment, the second cooling member 50 has a second heat transport body 51 which is a water cooling mechanism such as a water cooling jacket. The second heat transport body 51 absorbs heat from the second metal member 40 and discharges the heat to the outside. Specifically, the second heat transport body 51 has a hollow body 51a and a heat transport liquid 51b sealed in the hollow body 51a. In the present embodiment, the second heat transport body 51 has a metal member having a flow path as the hollow body 51a, and has a cooling medium such as water (refrigerant) or antifreeze as the heat transport liquid 51b.

{Circle around (2)} The second cooling member 50 has a second protruding portion 50a protruding from the front end face of the semiconductor laser device 10. The second protrusion 50a further protrudes from the front end surface of the second metal member 40. That is, similarly to the first cooling member 30, the second cooling member 50 has a structure protruding from the semiconductor laser element 10 and the second metal member 40.

As described above, the second cooling member 50 is connected to the second metal member 40 disposed on the p-side of the semiconductor laser device 10, and the second projection protruding from the front end surface of the semiconductor laser device 10 is connected to the second cooling member 50. By providing 50a, not only the n-side but also the p-side of the semiconductor laser device 10 can increase the heat diffusion cross-sectional area of the heat generated near the front end face of the semiconductor laser device 10. Thereby, the heat in the vicinity of the front end face of the semiconductor laser device 10 can be more efficiently radiated.

In the second cooling member 50 of the present embodiment, the tip of the second heat transport body 51 of the second cooling member 50 is included in the second protrusion 50a. That is, the tip of the second heat transport body 51 protrudes from the front end face of the semiconductor laser device 10.

Accordingly, the distal end of the second heat transport body 51 having substantially the cooling function in the second cooling member 50 can be made to protrude from the front end surface of the semiconductor laser device 10. Therefore, heat in the vicinity of the front end face of the semiconductor laser device 10 can be more efficiently radiated.

In the semiconductor laser device 1 configured as described above, as shown in FIG. 7, laser light emitted from the semiconductor laser element 10 has a divergence angle θ (divergence angle) from a light emitting point on the front end face of the semiconductor laser element 10. Radiated. FIG. 7 is an enlarged sectional view of the semiconductor laser device 1 according to the first embodiment.

As shown in FIG. 7, the spread angle θ of the laser light emitted from the semiconductor laser element 10 is such that the laser light spreads with respect to an extension of the optical waveguide (specifically, the center of the light emitting layer 13) of the semiconductor laser element 10. It is an angle. Specifically, the spread angle θ is an angle at which the intensity of light emitted from the front end face (light emission surface) of the semiconductor laser device 10 becomes に対して of the maximum intensity.

Here, the first cooling member 30 and the second cooling member 50 may satisfy the following conditions.

First, as for the first cooling member 30, the distance from the connection surface between the first metal member 20 and the first cooling member 30 to the first heat transport body 31 of the first cooling member 30 is d11, and Assuming that the distance from the front end face to the tip of the first protruding portion 30a of the first cooling member 30 is L1, it is preferable that the following formula (1) is satisfied. In the present embodiment, the connection surface between first metal member 20 and first cooling member 30 is the upper surface of first metal member 20 and the lower surface of first cooling member 30 (specifically, Surface).

Since heat is diffused in the direction of about 45 °, by satisfying the relationship of (Equation 1), the heat diffusion from the first metal member 20 is not hindered. That is, the first protrusion 30a of the first cooling member 30 can secure a heat diffusion path in the 45 ° direction. This makes it possible to reduce the thermal resistance in the heat radiation structure on the n-side of the semiconductor laser element 10, so that heat near the front end face of the semiconductor laser element 10 can be effectively radiated, and the device characteristics of the semiconductor laser element 10 can be reduced. Can be further improved.

Further, the first metal member 20 extends from the optical waveguide (specifically, the center of the light emitting layer 13) in a second direction (z direction in FIG. 7) orthogonal to the first direction (x direction in FIG. 7) from which the laser light is emitted. Assuming that the distance between the laser beam and the first cooling member 30 is d12, the divergence angle θ of the laser light emitted from the semiconductor laser device 10, and the distance L1 and the distance d12 have the following relationship (Equation 2). Good to meet.

を満たす By satisfying the relationship of (Equation 2) in this way, it is possible to prevent the laser light emitted from the semiconductor laser element 10 from being blocked by the first protrusion 30a of the first cooling member 30.

Similarly, for the second cooling member 50, the distance from the connection surface between the second metal member 40 and the second cooling member 50 to the second heat transport body 51 of the second cooling member 50 is d21, and the semiconductor laser element Assuming that the distance from the front end surface of the second cooling member 50 to the tip of the second protruding portion 50a of the second cooling member 50 is L2, it is preferable that the following formula (3) is satisfied. In the present embodiment, the connection surface between the second metal member 40 and the second cooling member 50 is the lower surface of the second metal member 40 and the upper surface of the second cooling member 50.

を満たす By satisfying the relationship of (Equation 3), heat diffusion from the second metal member 40 is not hindered. That is, a heat diffusion path in the 45 ° direction can be secured by the second projecting portion 50a of the second cooling member 50. This makes it possible to reduce the thermal resistance not only in the heat radiation structure on the n-side but also in the heat radiation structure on the p-side of the semiconductor laser device 10, so that the heat near the front end face of the semiconductor laser device 10 can be more effectively radiated. Accordingly, the device characteristics of the semiconductor laser device 10 can be further improved.

Further, the second metal member 40 extends from the optical waveguide (specifically, the center of the light emitting layer 13) in a second direction (z direction in FIG. 7) orthogonal to the first direction (x direction in FIG. 7) from which the laser light is emitted. Assuming that the distance between the laser beam and the connecting surface between the second cooling member 50 and the second cooling member 50 is d22, the divergence angle θ of the laser beam emitted from the semiconductor laser device 10 and the distance L2 and the distance d22 have the following relationship (Equation 4). Good to meet.

を満たす By satisfying the relationship of (Equation 4) in this way, it is possible to prevent the laser light emitted from the semiconductor laser element 10 from being blocked by the second protrusion 50a of the second cooling member 50.

(Embodiment 2)
Next, a semiconductor laser device 1A according to a second embodiment will be described with reference to FIGS. FIG. 8 is a perspective view of a semiconductor laser device 1A according to the second embodiment. FIG. 9 is a sectional view of the semiconductor laser device 1A. FIG. 10 is an enlarged cross-sectional view around the front part of the semiconductor laser element 10 in the semiconductor laser device 1A.

半導体 The semiconductor laser device 1A according to the present embodiment is different from the semiconductor laser device 1 according to the first embodiment in the configuration of the first cooling member. Specifically, in the semiconductor laser device 1 according to the first embodiment, the first cooling member 30 has a configuration including a heat pipe, whereas in the semiconductor laser device 1A according to the present embodiment, The member 30A has a first heat transport body 31A that is a water cooling mechanism such as a water cooling jacket. That is, in the semiconductor laser device 1A of the present embodiment, both the first cooling member 30A and the second cooling member 50 have a water cooling mechanism, and both the upper and lower sides of the semiconductor laser element 10 are cooled by the water cooling mechanism. Note that the configuration other than the first cooling member is the same as the configuration of the semiconductor laser device 1A of the present embodiment and the semiconductor laser device 1 of the first embodiment.

The first heat transporter 31A of the first cooling member 30A absorbs heat from the first metal member 20 and discharges the heat to the outside. Specifically, the first heat transport body 31A has a hollow body 31Aa and a heat transport liquid 31Ab sealed in the hollow body 31Aa, like the second heat transport body 51. In the present embodiment, the first heat transport body 31A has a metal member having a flow path as the hollow body 31Aa, and has a cooling medium such as water (refrigerant) or antifreeze as the heat transport liquid 31Ab.

As described above, also in the semiconductor laser device 1A of the present embodiment, since the first cooling member 30A has the first protrusion 30a, heat near the front end face of the semiconductor laser element 10 can be efficiently radiated. . As a result, it is possible to suppress a decrease in optical output and a decrease in reliability of the semiconductor laser device 10, and to improve device characteristics of the semiconductor laser device 10.

Further, also in semiconductor laser device 1A of the present embodiment, since second cooling member 50 has second projecting portion 50a, heat near the front end face of semiconductor laser element 10 can be more efficiently radiated. it can.

Also, in the semiconductor laser device 1A of the present embodiment, the first cooling member 30A may satisfy the following conditions, similarly to the first cooling member 30 of the semiconductor laser device 1 of the first embodiment. .

Specifically, the distance from the connection surface between the first metal member 20 and the first cooling member 30A to the first heat transporter 31A of the first cooling member 30A is d11, and the distance from the front end face of the semiconductor laser device 10 to the first Assuming that the distance to the tip of the first protrusion 30a of the cooling member 30A is L1, it is preferable that the following expression (1) is satisfied. Also in the present embodiment, the connection surface between first metal member 20 and first cooling member 30A is the upper surface of first metal member 20 and the lower surface of first cooling member 30A.

を満たす By satisfying the relationship of (Equation 1) in this way, heat diffusion from the first metal member 20 is not hindered. That is, a heat diffusion path in a 45 ° direction can be secured by the first protrusion 30a of the first cooling member 30A. This makes it possible to reduce the thermal resistance in the heat radiation structure on the n-side of the semiconductor laser element 10, so that heat near the front end face of the semiconductor laser element 10 can be effectively radiated, and the device characteristics of the semiconductor laser element 10 can be reduced. Can be further improved.

Further, the first metal member 20 extends from the optical waveguide (specifically, the center of the light emitting layer 13) in a second direction (z direction in FIG. 10) orthogonal to the first direction (x direction in FIG. 10) from which the laser light is emitted. Assuming that the distance between the laser beam and the first cooling member 30A is d12, the divergence angle θ of the laser light emitted from the semiconductor laser device 10, and the distance L1 and the distance d12 have the following relationship (Equation 2). Good to meet.

を満たす By satisfying the relationship of (Equation 2) in this way, it is possible to prevent the laser light emitted from the semiconductor laser element 10 from being blocked by the first protrusion 30a of the first cooling member 30A.

Note that the second cooling member 50 preferably satisfies the relations of the above (Equation 3) and (Equation 4) as in the first embodiment.

(Embodiment 3)
Next, a semiconductor laser device 1B according to a third embodiment will be described with reference to FIGS. FIG. 11 is a perspective view of a semiconductor laser device 1B according to the third embodiment. FIG. 12 is a sectional view of the semiconductor laser device 1B. FIG. 13 is an enlarged cross-sectional view around the front part of the semiconductor laser element 10 in the semiconductor laser device 1B.

半導体 The semiconductor laser device 1B according to the present embodiment is different from the semiconductor laser device 1 according to the first embodiment in the configuration of the first cooling member and the second cooling member. Specifically, in the semiconductor laser device 1 according to the first embodiment, the first cooling member 30 includes the first heat transport body 31 and the second cooling member 50 includes the second heat transport body 51. On the other hand, in the semiconductor laser device 1B in the present embodiment, each of the first cooling member 30B and the second cooling member 50B is configured only by a metal member.

Specifically, the first cooling member 30B and the second cooling member 50B are configured by a metal block such as a copper block. That is, in the present embodiment, not only the first metal member 20 and the second metal member 40 sandwiching the semiconductor laser element 10 are constituted by metal blocks, but also the first cooling member 30B and the second cooling member 50B are made of metal. It is composed of blocks. In other respects, the configuration of the semiconductor laser device 1B of the present embodiment is the same as that of the semiconductor laser device 1 of the first embodiment.

As described above, also in the semiconductor laser device 1B of the present embodiment, since the first cooling member 30B has the first protrusion 30a, heat near the front end face of the semiconductor laser element 10 can be efficiently radiated. . As a result, it is possible to suppress a decrease in optical output and a decrease in reliability of the semiconductor laser device 10, and to improve device characteristics of the semiconductor laser device 10.

Further, also in semiconductor laser device 1B in the present embodiment, since second cooling member 50B has second projecting portion 50a, heat near the front end face of semiconductor laser element 10 can be more efficiently radiated. it can.

Also, in the semiconductor laser device 1B of the present embodiment, the first cooling member 30B and the second cooling member 50B are the same as the first cooling member 30 and the second cooling member 50 of the semiconductor laser device 1 of the first embodiment. Similarly, the following conditions should be satisfied.

Specifically, the distance from the connection surface between the first metal member 20 and the first cooling member 30B to the upper surface of the first cooling member 30B is d13, and the distance from the front end surface of the semiconductor laser device 10 to the first cooling member 30B is Assuming that the distance to the tip of the one protrusion 30a is L1, it is preferable that the following relationship (Equation 5) is satisfied. In the present embodiment, the connection surface between first metal member 20 and first cooling member 30B is the upper surface of first metal member 20 and the lower surface of first cooling member 30B. That is, the distance d13 is the thickness of the first cooling member 30B.

を満たす By satisfying the relationship of (Equation 5) in this way, heat diffusion from the first metal member 20 is not hindered. In other words, a heat diffusion path in the 45 ° direction can be secured by the first protrusion 30a of the first cooling member 30B. This makes it possible to reduce the thermal resistance in the heat radiation structure on the n-side of the semiconductor laser element 10, so that heat near the front end face of the semiconductor laser element 10 can be effectively radiated, and the device characteristics of the semiconductor laser element 10 can be reduced. Can be further improved.

Further, the first metal member 20 extends from the optical waveguide (specifically, the center of the light emitting layer 13) in a second direction (z direction in FIG. 13) orthogonal to the first direction (x direction in FIG. 13) from which the laser light is emitted. Assuming that the distance from the laser beam to the connecting surface between the first cooling member 30B and the first cooling member 30B is d12, the spread angle θ of the laser light emitted from the semiconductor laser device 10, the distance L1 and the distance d12 have the following relationship (Equation 2). Good to meet.

を満たす By satisfying the relationship of (Equation 2) in this way, it is possible to prevent the laser light emitted from the semiconductor laser element 10 from being blocked by the first protrusion 30a of the first cooling member 30B.

Similarly, for the second cooling member 50B, the distance from the connection surface between the second metal member 40 and the second cooling member 50B to the second cooling member 50B is d23, and the distance from the front end surface of the semiconductor laser device 10 to the second cooling member 50B is d23. Assuming that the distance from the cooling member 50B to the tip of the second protrusion 50a is L2, the following relationship (Equation 6) may be satisfied. In the present embodiment, the connection surface between second metal member 40 and second cooling member 50B is the lower surface of second metal member 40 and the upper surface of second cooling member 50B. That is, the distance d23 is the thickness of the second cooling member 50B.

を満たす By satisfying the relationship of (Equation 6) in this way, heat diffusion from the second metal member 40 is not hindered. That is, a heat diffusion path in the 45 ° direction can be secured by the second protrusion 50a of the second cooling member 50B. This makes it possible to reduce the thermal resistance not only in the heat radiation structure on the n-side but also in the heat radiation structure on the p-side of the semiconductor laser device 10, so that the heat near the front end face of the semiconductor laser device 10 can be more effectively radiated. Accordingly, the device characteristics of the semiconductor laser device 10 can be further improved.

In addition, the second metal member 40 extends from the optical waveguide (specifically, the center of the light emitting layer 13) in a second direction (z direction in FIG. 13) orthogonal to the first direction (x direction in FIG. 13) from which the laser light is emitted. Assuming that the distance between the laser beam and the connecting surface between the second cooling member 50B and the second cooling member 50B is d22, the divergence angle θ of the laser light emitted from the semiconductor laser element 10 and the distance L2 and the distance d22 have the following relationship (Equation 4). Good to meet.

を満たす By satisfying the relationship of (Equation 4) in this way, it is possible to prevent the laser light emitted from the semiconductor laser element 10 from being blocked by the second protrusion 50a of the second cooling member 50B.

As shown in FIGS. 14 and 15, in the semiconductor laser device 1B according to the embodiment, the inclined surface 30b is formed on the lower surface (the surface on the semiconductor laser element 10 side) of the first protrusion 30a of the first cooling member 30B. It may be. The inclined surface 30b is formed such that the thickness of the first protrusion 30a gradually decreases toward the tip of the first protrusion 30a. In FIG. 15, the inclination angle α of the inclined surface 30b is cut so that the first cooling member 30B is inclined with respect to the extension of the optical waveguide of the semiconductor laser device 10 (specifically, the center of the light emitting layer 13). It is an angle.

At this time, it is preferable that the inclination angle α and the distance d12, the distance d13, the distance L1, and the spread angle θ satisfy the following relations (Equation 7) and (Equation 8).

By satisfying the relations of (Equation 7) and (Equation 8) in this manner, the laser light emitted from the semiconductor laser element 10 is not blocked by the first protrusion 30a of the first cooling member 30B, and is not rotated by 45 °. The length (distance L1) of the first protruding portion 30a that can secure the heat diffusion path can be increased. Therefore, heat near the front end face of the semiconductor laser device 10 can be more effectively radiated.

(Other modifications)
Although the semiconductor laser device according to the present disclosure has been described based on the embodiments, the present disclosure is not limited to the first to third embodiments.

For example, in the first to third embodiments, the semiconductor laser device 10 has a multi-emitter structure having a plurality of light-emitting points, but is not limited thereto, and may have a single-emitter structure having one light-emitting point. In this case, a semiconductor laser array in which a plurality of semiconductor laser chips having a single emitter structure are arranged may be used as the semiconductor laser element.

In the first to third embodiments, the semiconductor laser device 10 has a ridge stripe structure, but is not limited thereto, and may have an electrode stripe structure.

In the first to third embodiments, the semiconductor laser element 10 is mounted (junction down mounting) so that the p-side electrode 16 faces the submount 70 (downward). However, the present invention is not limited to this. 16 (junction-up mounting) so that 16 is on the submount 70 side (upward).

In the first to third embodiments, the semiconductor laser element 10 is used as the light source. However, instead of the semiconductor laser element 10, another semiconductor light emitting element such as a super luminescent diode (SLD: Super Luminescent Diode) is used. May be used.

In addition, a form obtained by applying various modifications that can be conceived by those skilled in the art to each of the above-described embodiments, and realized by arbitrarily combining components and functions in each of the embodiments without departing from the gist of the present disclosure. This embodiment is also included in the present disclosure.

The semiconductor laser device according to the present disclosure has excellent heat radiation properties, and is used as a light source for image display used in projectors, etc., a processing light source used in laser processing devices, or an illumination light source used in industrial spot lighting and the like. And is particularly useful as a light source for equipment requiring relatively high light output.

DESCRIPTION OF

SYMBOLS

1, 1A, 1B Semiconductor laser device 10 Semiconductor laser element 11 Semiconductor substrate 12 N-type semiconductor layer 13 Light emitting layer 14 P-type semiconductor layer 15 Contact layer 16 P-side electrode 17 N-side electrode 20 First metal member 21

First electrode terminal

30 , 30A, 30B First cooling member 30a First protruding portion 30b Inclined

surface

31, 31A First heat transport body 31a, 31Aa, 51a Hollow body 31b, 31Ab, 51b Heat transport liquid 32 Endothermic body 33 Discharge body 40 Second metal Member 40a Recess 41

Second electrode terminal

50, 50B Second cooling member 50a Second protrusion 51 Second heat transporter 60 Spacer 70 Submount 71 Main body 72 Metal layer 81 First joining member 82 Second joining member

Claims

A semiconductor laser element for emitting laser light,
A first metal member disposed on the n-side of the semiconductor laser element;
A second metal member disposed on the p-side of the semiconductor laser element;
A first cooling member connected to the first metal member,
The first cooling member has a first protrusion protruding from a front end surface of the semiconductor laser device,
Semiconductor laser device.
The first cooling member has a first heat transporter,
The tip of the first heat transporter is included in the first protrusion,
The semiconductor laser device according to claim 1.
The first heat transport body has a hollow body, and a heat transport liquid sealed in the hollow body.
The semiconductor laser device according to claim 2.
The distance from the connection surface between the first metal member and the first cooling member to the first heat transporter is d11,
When the distance from the front end face of the semiconductor laser element to the tip of the first protrusion is L1,
satisfies the relationship of d11 ≦ L1,
The semiconductor laser device according to claim 2.
The spread angle of the laser light emitted from the semiconductor laser element is θ,
The distance from the optical waveguide of the semiconductor laser element to the connection surface between the first metal member and the first cooling member in a second direction orthogonal to the first direction in which the laser light is emitted is d12,
When the distance from the front end face of the semiconductor laser element to the tip of the first protrusion is L1,
Satisfying a relationship of L1 ≦ d12 / tan θ,
The semiconductor laser device according to any one of claims 1 to 4.
A second cooling member connected to the second metal member;
The second cooling member has a second protrusion protruding from a front end surface of the semiconductor laser device,
The semiconductor laser device according to any one of claims 1 to 5.
The second cooling member has a second heat transporter,
The tip of the second heat transporter is included in the second protrusion,
A semiconductor laser device according to claim 5.
The second heat transport body has a hollow body, and a heat transport liquid sealed in the hollow body,
A semiconductor laser device according to claim 7.
The distance from the connection surface between the second metal member and the second cooling member to the second heat transporter is d21,
When a distance from the front end face of the semiconductor laser element to the tip of the second protrusion is L2,
satisfying the relationship of d21 ≦ L2,
A semiconductor laser device according to claim 7.
The spread angle of the laser light emitted from the semiconductor laser element is θ,
The distance from the optical waveguide of the semiconductor laser element to the connection surface between the second metal member and the second cooling member in a second direction orthogonal to the first direction in which the laser light is emitted is d22,
When a distance from the front end face of the semiconductor laser element to the tip of the second protrusion is L2,
Satisfying the relationship of L2 ≦ d22 / tan θ,
The semiconductor laser device according to any one of claims 6 to 9.
An inclined surface is formed on a surface of the first protrusion on the semiconductor laser element side;
The semiconductor laser device according to any one of claims 1 to 10.
The semiconductor laser device is disposed on the second metal member by junction-down mounting,
The semiconductor laser device according to any one of claims 1 to 11.
The second metal member has a concave portion,
The semiconductor laser device is mounted on a submount arranged in the concave portion,
The semiconductor laser device according to claim 12.