Semiconductor laser module, method for manufacturing the same and laser processing device

Abstract

To provide a semiconductor laser module capable of restraining deterioration in long-term reliability of a laser diode element.SOLUTION: A semiconductor laser module includes a heat sink, a first electrode disposed in the first region of the heat sink, an insulating layer disposed on the first electrode, a sub-mount that is disposed in the second region of the heat sink and has electrical conductivity and thermal conductivity, a laser diode element that is disposed on the sub-mount and emits laser light, a power supply structure that is disposed on the laser diode element and has electrical conductivity, thermal conductivity and elasticity, and a second electrode provided so as to contact the top portions of the insulating layer and the power supply structure. The second electrode has an electrode facing portion having a flat surface in contact with the insulating layer, and a convex portion that has a flat surface in contact with the power supply structure and protrudes toward the heat sink side beyond the electrode facing portion. The power supply structure is configured by a ribbon-shaped wave-shaped structure disposed between the laser diode element and the second electrode.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to a semiconductor laser module that outputs laser light, a method for manufacturing the same, and a laser processing apparatus.

Background Art

[0002] In high-power laser devices typified by light sources for laser processing apparatuses, high-output light is obtained by optically coupling the oscillation light from a plurality of semiconductor laser modules. In order to obtain further output, it is dealt with by either increasing the number of semiconductor laser modules or increasing the output of each semiconductor laser module. When the number of semiconductor laser modules is increased, the laser device becomes large-sized, so it is desirable to increase the output of each semiconductor laser module. Increasing the output of the semiconductor laser module is accompanied by an increase in the amount of heat generated, so there are problems with the output characteristics and long-term reliability due to the increase in the driving temperature of the laser diode element. For this reason, a structure of a semiconductor laser module having high heat dissipation performance has been developed.

[0003] Patent Document 1 discloses a semiconductor laser device having a lower electrode block having a notch-shaped recess in a part of an upper surface, an insulating layer provided on the upper surface other than the notch-shaped recess of the lower electrode block, an upper electrode block disposed on the insulating layer, a submount disposed on the upper surface of the notch-shaped recess, a laser diode element disposed on the submount, a plurality of bumps connecting the laser diode element and the upper electrode block, and a fastening member for fastening the lower electrode block and the upper electrode block. Further, the depth of the notch-shaped recess of the lower electrode block is made shallower than the total thickness of the thickness of the laser diode element and the thickness of the bump. As a result, the bump is deformed during assembly, the laser diode element and the upper electrode block are electrically connected, and heat generated from the laser diode element can be simultaneously released to the two electrode blocks. As a result, the heat dissipation performance of the semiconductor laser device described in Patent Document 1 is improved.

Prior Art Documents

Patent Documents

[0004] [Patent Document 1] International Publication No. 2019 / 009086 [Summary of the Invention] [Problems to be Solved by the Invention]

[0005] However, according to the above conventional technology, after arranging a plurality of bumps with pointed tips on the upper surface of the laser diode element, the upper electrode block is attached. At this time, in order to sufficiently contact the upper ends of the plurality of bumps with the upper electrode block, the plurality of bumps with pointed tips must be flattened. Since the plurality of bumps have a solid structure filled with metal up to the inside, stress is required to change the shape of the plurality of bumps when attaching the upper electrode block. This stress is applied not only to the plurality of bumps but also to the laser diode element disposed under the plurality of bumps. That is, in the conventional technology, a large load is applied to the laser diode element during the manufacture of the semiconductor laser device. There has been a problem that when the load applied to the laser diode element increases, the long-term reliability of the laser diode element decreases.

[0006] The present disclosure has been made in view of the above, and an object thereof is to obtain a semiconductor laser module capable of suppressing a decrease in the long-term reliability of a laser diode element. [Means for Solving the Problems]

[0007] In order to solve the above-described problems and achieve the object, a semiconductor laser module according to the present disclosure includes a heat sink, a first electrode disposed in a first region of the heat sink, an insulating layer disposed on the first electrode, a submount disposed in a second region different from the first region of the heat sink and having conductivity and thermal conductivity, a laser diode element disposed on the submount and emitting laser light, a power supply structure disposed on the laser diode element and having conductivity, thermal conductivity, and elasticity, and a second electrode provided so as to be in contact with the insulating layer and the power supply structure. The second electrode has an electrode facing portion having a flat surface in contact with the insulating layer, and a convex portion having a flat surface in contact with the power supply structure and protruding toward the heat sink side from the electrode facing portion. The power supply structure is constituted by a ribbon-shaped corrugated structure portion disposed between the laser diode element and the second electrode.

Advantages of the Invention

[0008] According to the present disclosure, there is an effect that a decrease in the long-term reliability of the laser diode element can be suppressed.

Brief Description of the Drawings

[0009]

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Embodiments for Carrying Out the Invention

[0010] Hereinafter, the semiconductor laser module, its manufacturing method, and the laser processing apparatus according to the embodiments of the present disclosure will be described in detail with reference to the drawings.

[0011] Embodiment 1. FIG. 1 is a perspective view schematically showing an example of the configuration of the semiconductor laser module according to Embodiment 1. FIG. 2 is a partial cross-sectional view schematically showing an example of the configuration of the semiconductor laser module according to Embodiment 1. FIG. 3 is a front view schematically showing an example of the configuration of the semiconductor laser module according to Embodiment 1. Hereinafter, the emission direction of the laser light L is defined as the Z-axis direction, the direction in which the members constituting the semiconductor laser module 10 are stacked in a direction perpendicular to the Z-axis is defined as the Y-axis direction, and the direction perpendicular to both the Z-axis and the Y-axis is defined as the X-axis direction. Hereinafter, the two relative positional relationships in the Y-axis direction are expressed using up and down. Also, the side where the laser diode element 16 is provided is defined as the front in a plane perpendicular to the Z-axis direction. FIG. 2 corresponds to the YZ cross-section of FIG. 1. Further, FIG. 3 shows a front view in a state where the Slow Axis Collimator (SAC) 32 is removed.

[0012] The semiconductor laser module 10 includes a heat sink 11, an anode electrode 12, an insulating sheet 13, a cathode electrode 14, a submount 15, a laser diode element 16, and a power supply structure 17.

[0013] The heat sink 11 is a heat dissipation member for suppressing the temperature rise of the laser diode element 16. The heat sink 11 has a flat plate-like structure extending in the Z-axis direction. The heat sink 11 is made of a material with good thermal conductivity. Here, the heat sink 11 is made of a conductive material. In one example, the heat sink 11 is made of copper (Cu). Also, a water channel for flowing cooling water may be provided inside the heat sink 11. The upper surface of the heat sink 11 has an electrode arrangement region R1 corresponding to the first region and an element arrangement region R2 corresponding to the second region.

[0014] The anode electrode 12 having an L shape in the XY plane is arranged in the electrode arrangement region R1 of the heat sink 11. The anode electrode 12 is composed of an L-shaped member having a plate-like first portion 121 parallel to the YZ plane and a plate-like second portion 122 parallel to the ZX plane. The anode electrode 12 is an electrode connected to the P-type semiconductor side of the laser diode element 16. The anode electrode 12 is connected to a power supply (not shown) and supplies current to the laser diode element 16. The anode electrode 12 and the heat sink 11 are electrically connected. An example of the anode electrode 12 is copper. In this example, the anode electrode 12 corresponds to the first electrode.

[0015] The cathode electrode 14 is disposed on the second portion 122 of the anode electrode 12 via the insulating sheet 13. The cathode electrode 14 has substantially the same shape and size as the heat sink 11 in the ZX plane. That is, the cathode electrode 14 has a structure that protrudes more in the Z-axis direction than the anode electrode 12 in the ZX plane. In the X-axis direction, the cathode electrode 14 is disposed at an interval so as not to contact the first portion 121 of the anode electrode 12. The cathode electrode 14 is an electrode connected to a power source (not shown) and supplies current to the laser diode element 16. The cathode electrode 14 is connected to the N-type semiconductor side of the laser diode element 16. The cathode electrode 14 also has a function of dissipating heat generated in the laser diode element 16. An example of the cathode electrode 14 is copper with a gold plating on its surface. In this example, the cathode electrode 14 corresponds to the second electrode.

[0016] The insulating sheet 13 is disposed on the second portion 122 of the anode electrode 12 and is an insulating layer provided to insulate the anode electrode 12 and the cathode electrode 14.

[0017] The laser diode element 16 is disposed in the element arrangement region R2 of the heat sink 11 via the submount 15. The submount 15 is fixed on the element arrangement region R2 of the heat sink 11. The submount 15 is an intermediate member for relaxing the stress generated in the laser diode element 16 due to the difference in the linear expansion coefficient between the heat sink 11 and the laser diode element 16. That is, it is desirable for the submount 15 to have a linear expansion coefficient between the linear expansion coefficient of the laser diode element 16 and the linear expansion coefficient of the heat sink 11. Further, the submount 15 is desirably thermally conductive to transfer heat from the laser diode element 16 to the heat sink 11, and is electrically conductive to obtain an electrical connection with the anode electrode 12 via the heat sink 11. An example of the material constituting the submount 15 is copper tungsten (CuW).

[0018] The laser diode element 16 is arranged and fixed on the submount 15. The laser diode element 16 has a PN junction parallel to the ZX plane and is an end-face emitting laser that emits laser light L in the Z-axis direction. In one example, the laser diode element 16 uses gallium arsenide (GaAs) as the substrate and indium gallium arsenide (InGaAs) as the active layer. The end face of the laser diode element 16 in the Z-axis direction is arranged to be substantially the same as the position of the end faces of the heat sink 11 and the cathode electrode 14 in the Z-axis direction. The surface of the laser diode element 16 is gold-plated.

[0019] A power supply structure 17 is arranged on the laser diode element 16. The power supply structure 17 electrically connects the laser diode element 16 and the cathode electrode 14, and has a function of improving the heat dissipation amount from the upper surface of the laser diode element 16 by having a contact form with a sufficiently large contact area with the laser diode element 16. The structure of the power supply structure 17 will be described later.

[0020] The upper part of the element arrangement region R2 of the heat sink 11 is covered by the cathode electrode 14. The submount 15, the laser diode element 16, and the power supply structure 17 are arranged in a space sandwiched between the heat sink 11 and the cathode electrode 14.

[0021] The anode electrode 12 is electrically connected to the laser diode element 16 through the heat sink 11 and the submount 15. The cathode electrode 14 is electrically connected to the laser diode element 16 through the power supply structure 17.

[0022] In the above description, the case where the heat sink 11 has conductivity is shown. However, the heat sink 11 may partially include an insulating layer. In this case, it is sufficient that the upper part of the heat sink 11 is made of a conductive material, or a conductive material is provided between the heat sink 11, the anode electrode 12, and the submount 15. Also, an example where the anode electrode 12 is arranged below and the cathode electrode 14 is arranged above is shown, but the arrangements of the anode electrode 12 and the cathode electrode 14 may be reversed. However, the laser diode element 16 is arranged such that the P-type semiconductor of the laser diode element 16 is located on the anode electrode 12 side and the N-type semiconductor of the laser diode element 16 is located on the cathode electrode 14 side.

[0023] The structure that emits the laser light L, which is composed of the heat sink 11, the anode electrode 12, the insulating sheet 13, the cathode electrode 14, the submount 15, the laser diode element 16, and the power supply structure 17, is hereinafter referred to as the laser emission unit 20.

[0024] The semiconductor laser module 10 further includes a Fast Axis Collimator (FAC) 31, a SAC 32, and a manifold 33.

[0025] The FAC 31 is provided on the end face in the Z-axis direction of the laser diode element 16 of the laser emission unit 20, and is an optical component that collimates the component in the fast axis direction of the laser light L emitted from the laser diode element 16. In one example, the FAC 31 is fixed to the end face in the Z-axis direction of the heat sink 11 with an adhesive 35.

[0026] The SAC 32 is an optical component that collimates the component in the slow axis direction of the laser light L that has passed through the FAC 31. The SAC 32 is arranged at a distance from the FAC 31.

[0027] The manifold 33 serves as the base material of the semiconductor laser module 10 and is fixed to the housing of the laser processing apparatus. The manifold 33 supports and fixes the heat sink 11, more specifically the laser emission unit 20, on its upper surface. Further, the manifold 33 is also a relay member having a water channel for introducing cooling water to the heat sink 11. A water channel for introducing cooling water to the heat sink 11 is provided inside the manifold 33. The water channel inside the manifold 33 is connected to the water channel provided in the heat sink 11 by a connecting member. An example of the material of the manifold 33 is SUS (Steel Use Stainless) 303.

[0028] The end portion of the manifold 33 in the Z-axis direction protrudes in the laser light L emission direction more than the end portion of the laser emission unit 20 on the manifold 33 in the Z-axis direction. SAC32 is fixed to this end portion by an adhesive 36. In FIG. 1, an example is shown in which the laser emission unit 20, FAC31, and SAC32 are integrated on the manifold 33, but SAC32 may be provided separately from the laser emission unit 20 and FAC31.

[0029] Next, a more detailed structure of the cathode electrode 14 will be described. FIG. 4 is a cross-sectional view schematically showing an example of the configuration in the vicinity of the laser diode element of the semiconductor laser module according to Embodiment 1. In Embodiment 1, the cathode electrode 14 has an electrode facing portion 141 and a convex portion 142 on the lower surface which is the surface on the heat sink 11 side. The electrode facing portion 141 has a flat surface facing the anode electrode 12. The convex portion 142 has a flat surface facing the laser diode element 16. The flat surface of the convex portion 142 protrudes in a direction more perpendicular to the heat sink 11 side or the flat surface of the electrode facing portion 141 than the electrode facing portion 141.

[0030] In a state where the cathode electrode 14 is not disposed, a value obtained by subtracting the height h of the convex portion 142 from the total thickness of the insulating sheet 13 and the anode electrode 12 is made smaller than the total thickness of the submount 15, the laser diode element 16, and the power supply structure 17. Thereby, when the cathode electrode 14 is disposed to form the structure of the laser emission unit 20, the power supply structure 17 can be elastically deformed to increase the contact area between the laser diode element 16 and the power supply structure 17. As a result, the amount of heat exhausted from the laser diode element 16 to the cathode electrode 14 can be improved.

[0031] As described above, by providing the convex portion 142 on the cathode electrode 14 and providing the power supply structure 17 that can be elastically deformed, it becomes possible to effectively diffuse the heat generated in the laser diode element 16 within the cathode electrode 14.

[0032] Here, the structure of the power supply structure 17 will be described. The power supply structure 17 according to the first embodiment preferably has the following five requirements. (1) In a heat cycle for switching between energization and non-energization in the semiconductor laser module 10, the stress generated in the laser diode element 16 is sufficiently small. (2) At the temperature of the laser diode element 16 during energization, usually about 80° C., it does not bond to the gold plating on the surface of the laser diode element 16. (3) It has sufficiently high conductivity. (4) It has sufficiently high thermal conductivity. (5) During assembly, the stress generated in the laser diode element 16 is sufficiently small.

[0033] Note that when a material such as solder is used as the power supply structure 17, it may melt in a high temperature range and bond to the gold plating on the surface of the laser diode element 16. In this case, as a result of the power supply structure 17 having the requirement shown in (2) above bonding to the gold plating on the surface of the laser diode element 16, stress is likely to occur at the bonding portion, and the condition of (1) above cannot be satisfied.

[0034] Also, in the technology described in Patent Document 1, as described above, after arranging a plurality of bumps with pointed tips on the upper surface of the laser diode element, the upper electrode block is attached. At this time, in order to sufficiently contact the upper ends of the plurality of bumps with the upper electrode block, the plurality of bumps with pointed tips must be flattened, and stress for changing the shape of the plurality of bumps is required. This stress is applied not only to the plurality of bumps but also to the laser diode element disposed under the plurality of bumps. That is, in the technology described in Patent Document 1, when manufacturing the semiconductor laser device, a large stress is applied to the laser diode element, and the condition (5) above cannot be satisfied.

[0035] As the material of the power supply structure 17 that satisfies the above (1) to (5), a ribbon-shaped corrugated structure portion can be used. The ribbon-shaped corrugated structure portion is a ribbon-shaped member having a corrugated structure disposed between the laser diode element 16 and the cathode electrode 14. In Embodiment 1, the ribbon-shaped corrugated structure portion is constituted by a conductive ribbon having a thickness of several tens of μm. An example of the conductive ribbon is a gold ribbon or a copper ribbon. In Embodiment 1, the case where the ribbon-shaped corrugated structure portion is constituted by the conductive ribbon 17a will be described as an example.

[0036] FIG. 5 is a cross-sectional view showing an example of the structure of the power supply structure of the semiconductor laser module according to Embodiment 1. FIG. 5 shows a state in which the semiconductor laser module 10 is not completely assembled, that is, a state in which the power supply structure 17 is not deformed. As shown in FIG. 5, the conductive ribbon 17a is wavy and is bonded to the convex portion 142 of the cathode electrode 14. In a state where the semiconductor laser module 10 is not assembled, the top portion 171 of the wavy conductive ribbon 17a is in contact with the upper surface of the laser diode element 16. A gap 172 is formed between the conductive ribbon 17a and the laser diode element 16 and between the conductive ribbon 17a and the cathode electrode 14. The two surfaces of the conductive ribbon 17a are not arranged in parallel with the flat surface 142a of the convex portion 142 and the upper surface of the laser diode element 16 between the convex portion 142 of the cathode electrode 14 and the laser diode element 16. The two surfaces of the conductive ribbon 17a are arranged so as to contact at an angle not parallel to the flat surface 142a of the convex portion 142 and the upper surface of the laser diode element 16 between the convex portion 142 of the cathode electrode 14 and the laser diode element 16.

[0037] The dimensions of the conductive ribbon 17a and the gap 172 will be described in detail. FIG. 6 is a cross-sectional view showing an example of the shape of the ribbon before assembling the semiconductor laser module according to Embodiment 1. As shown in FIG. 6, the conductive ribbon 17a, which is a ribbon-shaped corrugated structure portion, is wavy, and the top of the conductive ribbon 17a on the cathode electrode 14 side is fixed to the cathode electrode 14 by being bonded to the flat surface 142a of the convex portion 142 of the cathode electrode 14 at a constant interval. That is, the portion of the top of the conductive ribbon 17a fixed to the flat surface 142a of the cathode electrode 14 becomes the bonding portion 173. In this way, the conductive ribbon 17a, which is a ribbon-shaped corrugated structure portion, is joined to the cathode electrode 14 at the bonding portion 173, which is a defined position, so as to be wavy. An example of the fixing method between the conductive ribbon 17a and the flat surface 142a in the bonding portion 173 is ultrasonic bonding or the like.

[0038] FIG. 7 is a bottom view showing an example of the arrangement of ribbons before the assembly of the semiconductor laser module according to Embodiment 1. FIG. 7 shows a view of the cathode electrode 14 with the conductive ribbon 17a joined thereto as seen from below. The broken line in FIG. 7 indicates the portion of the top 171 of the conductive ribbon 17a. One conductive ribbon 17a may be provided on the flat surface 142a of the cathode electrode 14, but a plurality of conductive ribbons 17a may be provided as shown in FIG. 7. That is, the power supply structure 17 is constituted by a plurality of conductive ribbons 17a each of which is a ribbon-shaped corrugated structure portion. The plurality of conductive ribbons 17a may be arranged in parallel in a defined direction or may be arranged in random directions. In the example of FIG. 7, three conductive ribbons 17a extending in the Z-axis direction are arranged in parallel in the X-axis direction on the flat surface 142a of the cathode electrode 14. Also, in the Z-axis direction, the positions of the lower tops 171 of the conductive ribbons 17a are made the same. Alternatively, the positions of the bonding portions 173 of all the conductive ribbons 17a are the same on the flat surface 142a of the cathode electrode 14 in the extending direction of the conductive ribbons 17a. More specifically, on the flat surface 142a, the bonding portions 173 are fixed at the same positions in the Z-axis direction.

[0039] FIG. 7 is an example and is not limited thereto. In Embodiment 1, any form may be adopted as long as a plurality of conductive ribbons 17a are arranged between the cathode electrode 14 and the laser diode element 16. In FIG. 7, a plurality of conductive ribbons 17a extending in the Z-axis direction are arranged at intervals in the X-axis direction. However, a plurality of conductive ribbons 17a extending in the X-axis direction may be arranged in parallel in the Z-axis direction. Further, the plurality of conductive ribbons 17a do not have to be arranged in parallel. FIG. 8 is a bottom view showing another example of the arrangement of the ribbons before the assembly of the semiconductor laser module according to Embodiment 1. In FIG. 8, two conductive ribbons 17aa extending in the Z-axis direction are arranged on the flat surface 142a of the cathode electrode 14, and one conductive ribbon 17ab arranged between the two conductive ribbons 17aa and having an extending direction different from the Z-axis direction is arranged. In the example of FIG. 8, the three conductive ribbons 17aa and 17ab are arranged in a Z shape. Thus, the extending directions of the conductive ribbons 17aa and 17ab may be different. Further, in FIG. 8, the conductive ribbons 17aa and 17ab are arranged in a Z shape, but the conductive ribbons 17a may be arranged in a W shape or in a zigzag shape.

[0040] FIG. 9 is a cross-sectional view showing an example of the shape of the ribbon after the assembly of the semiconductor laser module according to Embodiment 1. In order for the conductive ribbon 17a to contact the laser diode element 16 with a sufficiently large contact area, the gap 172 needs to be sufficiently small. At this time, the top 171 of the waveform of the conductive ribbon 17a on the laser diode element 16 side after assembly follows the shape of the surface of the laser diode element 16 and has a flat shape as shown in FIG. 9. The broken line A in FIG. 9 indicates the position of the flat surface 142a bonded to the conductive ribbon 17a of the convex portion 142 of the cathode electrode 14 in FIG. 5.

[0041] FIG. 10 is a cross-sectional view showing an example of the shape of a ribbon after assembly of the semiconductor laser module according to Embodiment 1. On the other hand, when the gap 172 becomes excessively small, as shown in FIG. 10, a part of the top 171 may buckle and lift off from the laser diode element 16 due to an unintended deformation of the conductive ribbon 17a. In this case, the contact area between the conductive ribbon 17a and the laser diode element 16 decreases by the amount of buckling. Therefore, in order for a sufficiently wide area of the top 171 to be deformed into a flat shape and not to buckle, it is desirable to appropriately select the dimensional values of the conductive ribbon 17a and the gap 172. In order for the shape of the conductive ribbon 17a after assembly to be as shown in FIG. 9, the distance between adjacent bonding portions 173 of the conductive ribbon 17a is about 450 μm, the distance in the Y-axis direction between the top 171 of the waveform and the flat surface 142a in the state shown in FIG. 6 before assembly is about 150 μm, and the dimension in the Y-axis direction of the gap 172 in the state shown in FIG. 9 after assembly is desirably about 130 μm. Note that the above dimensions are merely examples, and the dimensions may be arbitrarily changed as long as the shape of the conductive ribbon 17a after assembly is adjusted so that a part of the top 171 does not lift off from the laser diode element 16 as shown in FIG. 9. The broken line A in FIG. 10 indicates the position of the flat surface 142a bonded to the conductive ribbon 17a of the convex portion 142 of the cathode electrode 14 in FIG. 5.

[0042] As shown in FIG. 2, the submount 15, the laser diode element 16, and the power supply structure 17 are arranged on the element arrangement region R2 of the heat sink 11, and the anode electrode 12 and the insulating sheet 13 are arranged on the electrode arrangement region R1. In a state where the cathode electrode 14 is not arranged, as described above, the total thickness of the submount 15, the laser diode element 16, and the power supply structure 17 is larger than the value obtained by subtracting the height h of the convex portion 142 from the total thickness of the anode electrode 12 and the insulating sheet 13.

[0043] In this state, by arranging the cathode electrode 14, the conductive ribbon 17a will elastically deform according to the thicknesses of the anode electrode 12 and the insulating sheet 13 in the electrode arrangement region R1. FIG. 11 is a cross-sectional view showing an example of the structure of the conductive ribbon of the semiconductor laser module according to Embodiment 1. FIG. 11 shows the state where the semiconductor laser module 10 is assembled. As shown in FIG. 11, the top 171 of the conductive ribbon 17a on the laser diode element 16 side is crushed. The broken line A in FIG. 11 indicates the position of the flat surface 142a that is bonded to the conductive ribbon 17a of the convex portion 142 of the cathode electrode 14 in FIG. 5. After the semiconductor laser module 10 is assembled, due to the crushing of the conductive ribbon 17a, the total thickness of the submount 15, the laser diode element 16, and the power supply structure 17 is equal to the value obtained by subtracting the height h of the convex portion 142 from the total thickness of the anode electrode 12 and the insulating sheet 13.

[0044] Also, due to the crushing of the conductive ribbon 17a, the contact area between the conductive ribbon 17a and the laser diode element 16 increases. As a result, the heat generated in the laser diode element 16 is transmitted to the cathode electrode 14 via the conductive ribbon 17a. When the cathode electrode 14 is an isotropic material, the heat that reaches the cathode electrode 14 is known to diffuse along a 45° plane from the outer peripheral portion of the surface in contact with the conductive ribbon 17a that transmits the heat from the laser diode element 16, with reference to the flat surface 142a in contact with the conductive ribbon 17a. That is, from the contact portion of the conductive ribbon 17a, the heat diffuses within the cathode electrode 14 along a 45° plane, passes through the insulating sheet 13 and the anode electrode 12, and is finally exhausted to the heat sink 11, thereby exhausting the heat from the laser diode element 16.

[0045] In addition, in FIG. 11, as the conductive ribbon 17a is elastically deformed and the gap 172 between the conductive ribbon 17a and the laser diode element 16 is eliminated, stress is applied to the laser diode element 16, and the requirement (1) is no longer satisfied. By touching the conductive ribbon 17a to the laser diode element 16 without completely bonding it, as shown in FIG. 11, stress is less likely to occur at the contact point. Therefore, the height h of the convex portion 142 of the cathode electrode 14, the thickness of the anode electrode 12, and the thickness of the insulating sheet 13 are controlled so that the gap 172 between the conductive ribbon 17a and the laser diode element 16 and the gap 172 between the conductive ribbon 17a and the cathode electrode 14 do not disappear. In a state where the semiconductor laser module 10 is assembled, by controlling the distance between the flat surface 142a of the convex portion 142 of the cathode electrode 14 and the upper surface of the heat sink 11 to be 50 μm or more and 100 μm or less, heat dissipation to the cathode electrode 14 via the conductive ribbon 17a can be enhanced without generating stress between the conductive ribbon 17a and the laser diode element 16.

[0046] Next, a method for manufacturing the semiconductor laser module 10 having such a configuration will be described. FIGS. 12 to 18 are perspective views schematically showing an example of the procedure of the method for manufacturing the semiconductor laser module according to Embodiment 1. In the following description, terms regarding the vertical relationship of the surfaces of the constituent members are used based on the state of the semiconductor laser module 10 shown in FIGS. 1 to 3. That is, even if the upper surface of the constituent member shown in FIGS. 1 to 3 is located on the lower side in FIGS. 12 to 18, it is referred to as the upper surface, and even if the lower surface of the constituent member shown in FIGS. 1 to 3 is located on the upper side in FIGS. 12 to 18, it is referred to as the lower surface.

[0047] First, as shown in FIG. 12, arrange the cathode electrode 14 such that the flat surface 142a of the convex portion 142 of the cathode electrode 14 faces upward in FIG. 12. Next, apply an adhesive 201 to the electrode facing portion 141 of the cathode electrode 14. The adhesive 201 used here is an insulating adhesive. Thereafter, as shown in FIG. 13, bond an insulating sheet 13 onto the electrode facing portion 141 of the cathode electrode 14. That is, the steps shown in FIGS. 12 and 13 correspond to the step of bonding an insulating layer to the electrode facing portion 141 of the second electrode, which has an electrode facing portion 141 having a flat surface facing the first electrode and a convex portion 142 protruding in a direction perpendicular to the flat surface of the electrode facing portion 141 and having a flat surface 142a.

[0048] Next, apply an adhesive around the insulating sheet 13 on the electrode facing portion 141 of the cathode electrode 14. Thereafter, as shown in FIG. 14, overlap and bond the upper surface of the second portion 122 of the anode electrode 12 so as to contact the insulating sheet 13 bonded to the cathode electrode 14. Thus, the step shown in FIG. 14 corresponds to the step of bonding the first electrode to the electrode facing portion 141 of the second electrode via an insulating layer.

[0049] Next, as shown in FIG. 15, a conductive ribbon 17a is joined to the flat surface 142a of the convex portion 142 of the cathode electrode 14. A plurality of conductive ribbons 17a, which are power supply structures 17, are joined to the flat surface 142a of the convex portion 142. In one example, the plurality of conductive ribbons 17a are joined to the flat surface 142a of the convex portion 142 of the cathode electrode 14 as shown in FIG. 7 or FIG. 8. FIG. 15 also shows an enlarged view of the region R. The enlarged view shows that a plurality of conductive ribbons 17a are arranged in parallel in a direction orthogonal to the extending direction of the conductive ribbon 17a and joined to the flat surface 142a on the flat surface 142a of the convex portion 142. The conductive ribbon 17a is joined to the convex portion 142 of the cathode electrode 14 by a conductive adhesive in one example. The height of the conductive ribbon 17a is set to be higher than the distance between the flat surface 142a of the convex portion 142 of the cathode electrode 14 and the laser diode element 16 when the semiconductor laser module 10 is assembled. The height of the conductive ribbon 17a is the distance from the flat surface 142a of the convex portion 142 to the top 171 of the conductive ribbon 17a. Thus, the process shown in FIG. 15 corresponds to the process of joining a power supply structure 17 having conductivity, heat conductivity, and elasticity to the convex portion 142 of the second electrode to form the electrode structure 25. Then, the electrode structure 25 is manufactured by the processes from FIG. 12 to FIG. 15 described above.

[0050] In parallel with FIGS. 12 to 15, or before or after FIGS. 12 to 15, as shown in FIG. 16, a laser diode element 16 that emits laser light is joined to a submount 15 having conductivity and heat conductivity. In one example, the submount 15 and the laser diode element 16 are joined by a conductive adhesive. The process shown in FIG. 16 corresponds to the process of joining a laser diode element 16 that emits laser light onto a submount 15 having conductivity and heat conductivity.

[0051] Furthermore, a submount 15 to which a laser diode element 16 is joined is joined to an element arrangement region R2 of a heat sink 11. The element arrangement region R2 is a region that faces a convex portion 142 of the cathode electrode 14 when the semiconductor laser module 10 is assembled. As a result, as shown in FIG. 17, a heat sink 11 in which the laser diode element 16 is arranged is obtained. The process shown in FIG. 17 corresponds to the process of joining the submount 15 to the element arrangement region R2 of the heat sink 11.

[0052] Next, the electrode structure 25 manufactured in FIG. 15 and the heat sink 11 in which the laser diode element 16 manufactured in FIG. 17 is arranged are joined. Specifically, as shown in FIG. 18, a conductive adhesive 202 is applied to the lower surface 122a of the second portion 122 of the anode electrode 12 of the electrode structure 25. Then, the heat sink 11 is placed on the lower surface 122a of the anode electrode 12 to which the conductive adhesive 202 has been applied in FIG. 18. At this time, joining is performed while aligning the electrode structure 25 and the heat sink 11. Also, the heat sink 11 is turned upside down from the state of FIG. 17 so that the laser diode element 16 faces the conductive ribbon 17a.

[0053] Since the height of the conductive ribbon 17a is longer than the distance between the flat surface 142a of the convex portion 142 of the cathode electrode 14 and the laser diode element 16, the top portion 171 of the conductive ribbon 17a is deformed so as to contact the upper surface of the laser diode element 16 at this time. Also, since the thickness of the conductive ribbon 17a is thin and it is easily deformed, almost no force is required to deform the conductive ribbon 17a. As a result, when the electrode structure 25 and the heat sink 11 are joined, the load applied to the laser diode element 16 can be suppressed as compared with the conventional case. And in this way, the laser emitting portion 20 is obtained. Thus, the process shown in FIG. 18 corresponds to the process of joining the electrode structure 25 and the heat sink 11 such that the laser diode element 16 and the power supply structure 17 face each other and the electrode arrangement region R1, which is a region different from the element arrangement region R2 of the heat sink 11, and the first electrode face each other.

[0054] Thereafter, the FAC 31 is fixed to the laser emission unit 20 with an adhesive 35 or the like. The laser emission unit 20 with the FAC 31 fixed thereto is fixed to the upper surface of the manifold 33 with an adhesive or the like. Then, the SAC 32 is fixed to the end of the manifold 33 on the side where the laser beam L is emitted with an adhesive 36 or the like. Thus, the semiconductor laser module 10 shown in FIGS. 1 to 3 is manufactured.

[0055] Here, the effects of the semiconductor laser module 10 according to Embodiment 1 will be described in comparison with the technique described in Patent Document 1. In the technique described in Patent Document 1, a plurality of bumps with pointed tips are arranged between the laser diode element and the upper electrode block. Therefore, when manufacturing the semiconductor laser device, after arranging a plurality of bumps on the upper surface of the laser diode element, the upper electrode block is attached. At this time, in order to increase the contact area between the plurality of bumps and the upper electrode block, it is necessary to apply stress to deform the shape of the plurality of bumps so as to follow the lower surface of the upper electrode block.

[0056] FIG. 19 is a cross-sectional view schematically showing an example of the bumps between the laser diode element and the upper electrode block of a semiconductor laser device in the conventional technique. In the semiconductor laser device in the conventional technique, a plurality of bumps 517 are sandwiched between the laser diode element 516 and the upper electrode block 514. As shown in FIG. 19, the bump 517 has a solid structure with metal filled therein. Thus, a large stress is required to deform, that is, crush the bump 517 with a clogged interior.

[0057] On the other hand, in Embodiment 1, the power supply structure 17 disposed between the laser diode element 16 and the cathode electrode 14 is composed of a conductive ribbon 17a. As shown in FIG. 6 and the like, the conductive ribbon 17a has a waveform. However, in the portion surrounded by the conductive ribbon 17a and the flat surface 142a of the convex portion 142 of the cathode electrode 14, there is no metal like the bump 517, and it has a hollow structure. The stress for deforming, that is, crushing the hollow conductive ribbon 17a is smaller than that of the conventional bump 517 shown in FIG. 19. Thus, the stress required to crush the tip of the solid bump 517 is small compared to the stress required to crush the tip of the hollow conductive ribbon 17a. As a result, the stress applied to the laser diode element 16 is also smaller in the case of the conductive ribbon 17a than in the case of the bump 517.

[0058] And since the load acting on the laser diode element 16 during assembly is equal to the load required for the deformation of the power supply structure 17, by using the conductive ribbon 17a with a small cross-sectional area of the metal portion when cut along a plane parallel to the upper surface of the laser diode element 16, the load on the laser diode element 16 can be reduced compared to the case of the solid bump 517 with a large cross-sectional area of the metal portion. That is, the load applied to the laser diode element 16 is reduced, and there is an effect of improving the long-term reliability of the laser diode element 16.

[0059] In the technology described in Patent Document 1, between a plurality of bumps 517 and the upper electrode block 514, a metal sheet such as a gold foil and a metal layer that contacts the metal sheet to electrically connect the bump 517 and the upper electrode block 514 and enters the side surface of the bump 517 to reduce the contact resistance between the bump 517 and the upper electrode block 514 may be provided. That is, the metal sheet and the metal layer are provided to enhance the contact property between the upper electrode block 514, which is a hard and complete rigid body, and the soft bump 517. Thus, in Patent Document 1, a device for increasing the contact area between the hardly deformable bump 517 and the upper electrode block 514 is required. As a result, the configuration of the semiconductor laser device becomes complicated.

[0060] On the other hand, in the semiconductor laser module 10 according to Embodiment 1, since the conductive ribbon 17a is used as the power supply structure 17, the conductive ribbon 17a can be easily deformed. And the contact area of the conductive ribbon 17a with the laser diode element 16 can be sufficiently larger than that of the bump 517 in the case of Patent Document 1. As a result, there is no need to provide a metal sheet and a metal layer as in Patent Document 1 between the cathode electrode 14 and the conductive ribbon 17a. That is, by using the easily deformable conductive ribbon 17a, the structure can be simplified compared to Patent Document 1, and the assemblability can also be improved.

[0061] The effect will be described in comparison with the case where the power supply structure 17 is a single conductive ribbon 17a having a width substantially the same as the length of the laser diode element 16 in the X-axis direction. Consider the case where the upper surface of the laser diode element 16 is inclined in the X-axis direction in FIG. 7. In this case, when the electrode structure 25 and the heat sink 11 having the laser diode element 16 are joined, in the portion where the distance between the laser diode element 16 and the cathode electrode 14 is short, the conductive ribbon 17a contacts the upper surface of the laser diode element 16. Then, the crushing of the conductive ribbon 17a in this portion affects other portions. For this reason, in the portion where the distance between the laser diode element 16 and the cathode electrode 14 is long, the conductive ribbon 17a is only slightly crushed, and the conductive ribbon 17a is in a state of contacting the upper surface of the laser diode element 16 only slightly. That is, the shape of the conductive ribbon 17a cannot be changed in accordance with the inclination of the upper surface of the laser diode element 16.

[0062] On the other hand, as shown in FIG. 7 or FIG. 8, when a plurality of conductive ribbons 17a are arranged between the laser diode element 16 and the cathode electrode 14, even if the upper surface of the laser diode element 16 is inclined in the X-axis direction, each conductive ribbon 17a deforms according to the distance between the laser diode element 16 and the cathode electrode 14 at that location. As a result, at each location, the conductive ribbon 17a is crushed according to the distance between the laser diode element 16 and the cathode electrode 14, and the contact area between the conductive ribbon 17a and the laser diode element 16 can be made larger compared to the case where a single conductive ribbon 17a is arranged. Also, compared to the case of a single conductive ribbon 17a, the deviation in the size of the contact area between the conductive ribbon 17a and the laser diode element 16 is less likely to occur. When it is difficult to form the upper surface of the laser diode element 16 without inclination, by joining between the laser diode element 16 and the cathode electrode 14 using a plurality of conductive ribbons 17a, the amount of crushing of the conductive ribbon 17a with respect to the inclined surface can be adjusted, so that the contact area between the conductive ribbon 17a and the laser diode element 16 can be increased. Thereby, the electrical contact between the laser diode element 16 and the conductive ribbon 17a can be improved, and the heat conduction from the laser diode element 16 to the conductive ribbon 17a can be improved.

[0063] Also, as the power supply structure 17, by using a conductive ribbon 17a that does not bond to the gold plating used on the surface of the laser diode element 16, when the semiconductor laser module 10 is assembled, the power supply structure 17 elastically deforms. As a result, the contact area between the power supply structure 17 and the laser diode element 16 increases, and the amount of heat exhausted from the upper surface of the laser diode element 16 can be improved. Since the power supply structure 17 does not bond to the gold plating provided on the upper surface of the laser diode element 16, the stress generated in the laser diode element 16 can be made sufficiently small. As a result, damage to the laser diode element 16 due to stress can be suppressed.

[0064] Embodiment 2. In Embodiment 1, an example of the arrangement method of the conductive ribbon 17a, which is an example of the ribbon-shaped corrugated structure portion, is shown in FIG. 7 or FIG. 8. However, the arrangement method of the ribbon-shaped corrugated structure portion in the semiconductor laser module 10 of the present disclosure is not limited to these. In Embodiment 2, an example of the arrangement method of the ribbon-shaped corrugated structure portion will be described.

[0065] In FIG. 7, the position of the top 171 of the waveform or the position of the bonding portion 173 of the conductive ribbon 17a in the Z-axis direction, which is the extending direction, is the same for the plurality of conductive ribbons 17a arranged in parallel. That is, the positions of the bonding portions 173 of the conductive ribbons 17a, which are all ribbon-shaped corrugated structure portions, are the same in the extending direction of the conductive ribbons 17a. Also in FIG. 8, although the plurality of conductive ribbons 17a are not arranged in parallel, the position of the top 171 of the waveform or the position of the bonding portion 173 of the conductive ribbon 17a in the Z-axis direction is substantially the same among the plurality of conductive ribbons 17a.

[0066] As shown in FIGS. 7 and 8, when the positions of the tops 171 of the waveforms of the plurality of conductive ribbons 17a in the Z-axis direction are the same, a line-shaped or strip-shaped portion where the conductive ribbon 17a and the laser diode element 16 do not contact at all is formed and extends in the X-axis direction. When current flows in such a state, in the laser diode element 16, a portion where current flows concentratedly and a portion where current does not flow are generated. And when such a portion where current flows concentratedly and a portion where current does not flow are generated in the laser diode element 16, there is a possibility that a load is applied to the laser diode element 16. For this reason, it is desirable to arrange the conductive ribbon 17a so as to suppress the load applied to the laser diode element 16.

[0067] Therefore, in Embodiment 2, the positions of the tops 171 of the waveforms or the positions of the bonding portions 173 of the ribbon-shaped corrugated structure portions are arranged to be different among the plurality of ribbon-shaped corrugated structure portions in the extending direction of the ribbon-shaped corrugated structure portions.

[0068] FIG. 20 is a cross-sectional view showing an example of the arrangement of the ribbon-shaped corrugated structure portion before assembly in the semiconductor laser module according to Embodiment 2. FIG. 21 is a bottom view showing an example of the arrangement of the ribbon-shaped corrugated structure portion before assembly in the semiconductor laser module according to Embodiment 2. FIG. 21 shows a view of the cathode electrode 14 to which the ribbon-shaped corrugated structure portion is joined as seen from below. The broken line in FIG. 21 indicates the portion of the top 171 of the ribbon-shaped corrugated structure portion. In FIGS. 20 and 21, the positions of the tops 171 of the waveforms or the bonding portions 173 in the Z-axis direction of the adjacent ribbon-shaped corrugated structure portions are arranged to be different. Here, the ribbon-shaped corrugated structure portion has a conductive ribbon 17ac and a conductive ribbon 17ad.

[0069] The positions of the tops 171ac of the waveforms and the bonding portions 173ac in the Z-axis direction of the two conductive ribbons 17ac arranged on both sides in the X-axis direction are the same, but the positions of the tops 171ad of the waveforms and the bonding portions 173ad in the Z-axis direction of the conductive ribbon 17ad arranged in the center in the X-axis direction are different from those of the conductive ribbon 17ac. In this case, in the Z-axis direction, the position of the top 171ad of the waveform of the conductive ribbon 17ad is set to be the position of the bonding portion 173ac of the conductive ribbon 17ac, and the position of the bonding portion 173ad of the conductive ribbon 17ad is set to be the position of the top 171ac of the waveform of the conductive ribbon 17ac. Thus, the conductive ribbon 17ad is arranged to be shifted in the Z-axis direction with respect to the conductive ribbon 17ac. By arranging the conductive ribbons 17ac and 17ad in this way, the positions where the laser diode element 16 contacts the tops 171ac and 171ad of the conductive ribbons 17ac and 17ad form a lattice on the upper surface of the laser diode element 16. By arranging them in such a lattice pattern, concentration of the current density can be avoided.

[0070] As described above, in FIGS. 20 and 21, although an example is shown in which the positions of the tops 171ac, 171ad or bonding portions 173ac, 173ad of two ribbon-shaped corrugated structure portions adjacent to each other in a direction intersecting the extending direction of the ribbon-shaped corrugated structure portion are different in the extending direction, this is merely an example. It suffices that the positions of the tops 171ac, 171ad or bonding portions 173ac, 173ad of all the ribbon-shaped corrugated structure portions are not the same in the extending direction of the ribbon-shaped corrugated structure portion. In one example, the positions of the tops 171 or bonding portions 173 of a plurality of ribbon-shaped corrugated structure portions may be different in the extending direction of the ribbon-shaped corrugated structure portion. That is, the positions of the tops 171ac, 171ad or bonding portions 173ac, 173ad of the waveforms of all the conductive ribbons 17a in the Z-axis direction may be arranged to be different. Alternatively, the positions of the tops 171ac, 171ad or bonding portions 173ac, 173ad of the waveforms of at least one of the plurality of conductive ribbons 17a may be arranged to be different from those of the others.

[0071] Also, although the case where a plurality of conductive ribbons 17ac, 17ad extend in the Z-axis direction is shown here, the same applies when they extend in the X-axis direction or in other directions. Further, as shown in FIG. 8, even when a plurality of conductive ribbons 17a are not arranged in parallel, it suffices that the positions of the tops 171ac, 171ad or bonding portions 173ac, 173ad of the waveforms of all the conductive ribbons 17ac, 17ad are not the same in the X-axis direction.

[0072] In Embodiment 2, the positions of the tops 171ac and 171ad of all the ribbon-shaped corrugated structure portions or the bonding portions 173ac and 173ad are not made the same in the extending direction of the ribbon-shaped corrugated structure portions. As a result, the portions where the laser diode element 16 and the conductive ribbon 17a are in contact can be made evenly over the entire upper surface of the laser diode element 16. That is, it is possible to suppress the occurrence of a portion where current flows concentratedly and a portion where no current flows, which would otherwise solidify or occur unevenly on the upper surface of the laser diode element 16. As a result, it is possible to avoid the concentration of current density on the upper surface of the laser diode element 16, and there is an effect that the load applied to the laser diode element 16 can be reduced as compared with the cases of FIGS. 7 and 8. That is, there is an effect that it is possible to suppress the deterioration of the long-term reliability of the laser diode element 16.

[0073] Embodiment 3. As shown in FIG. 10, when the gap 172 becomes excessively small, a part of the conductive ribbon 17a in contact with the upper surface of the laser diode element 16 buckles and floats up from the upper surface of the laser diode element 16. As a result, the contact area between the conductive ribbon 17a and the laser diode element 16 is reduced by the amount that has floated up. To suppress this, in Embodiment 1, the distance between the bonding portions 173 or the range of the gap 172 in the extending direction of the conductive ribbon 17a was limited. In Embodiment 3, a configuration for suppressing the buckling of the conductive ribbon 17a by another method will be described.

[0074] FIG. 22 is a cross-sectional view showing an example of the arrangement of the ribbon-shaped corrugated structure portion before assembly in the semiconductor laser module according to Embodiment 3. FIG. 23 is a bottom view showing an example of the arrangement of the ribbon-shaped corrugated structure portion before assembly in the semiconductor laser module according to Embodiment 3. FIG. 23 shows a view of the cathode electrode 14 to which the ribbon-shaped corrugated structure portion is joined as seen from below. The broken lines in FIG. 23 indicate the portions of the tops 171ae, 171af of the ribbon-shaped corrugated structure portion. In Embodiments 1 and 2, the ribbon-shaped corrugated structure portion was constituted by one corrugated conductive ribbon 17a, but in Embodiment 3, the ribbon-shaped corrugated structure portion has a configuration in which a plurality of corrugated conductive ribbons 17ae, 17af having different lengths are stacked. That is, the ribbon-shaped corrugated structure portion has a conductive ribbon 17ae and a conductive ribbon 17af having different lengths. In this example, the conductive ribbon 17ae is longer than the conductive ribbon 17af and is disposed outside the conductive ribbon 17af. The conductive ribbons 17ae, 17af are constituted by, for example, gold (Au) or Cu.

[0075] In the example of FIG. 22, the ribbon-shaped corrugated structure portion at one position has a configuration in which two conductive ribbons 17ae, 17af having different lengths are stacked. In the state shown in FIG. 22 before assembly, the outer conductive ribbon 17ae has a longer length, and the inner conductive ribbon 17af has a shorter length. The two conductive ribbons 17ae, 17af are joined to the flat surface 142a of the cathode electrode 14 at the same bonding portion 173 to form a corrugated shape. In the state before assembly, the distance between the top 171ae of the outer conductive ribbon 17ae and the cathode electrode 14 is longer than the distance between the laser diode element 16 and the cathode electrode 14 after assembly. Similarly, the distance between the top 171af of the inner conductive ribbon 17af and the cathode electrode 14 is also longer than the distance between the laser diode element 16 and the cathode electrode 14 after assembly.

[0076] In this way, by overlapping and arranging two conductive ribbons 17ae and 17af with different lengths, the top 171af of the inner conductive ribbon 17af presses against the vicinity of the top 171ae of the outer conductive ribbon 17ae. As a result, even if buckling as shown in FIG. 10 is likely to occur due to the contact between the outer conductive ribbon 17ae and the laser diode element 16, the inner conductive ribbon 17af presses against the vicinity of the top 171ae of the outer conductive ribbon 17ae where buckling occurs, so that the occurrence of buckling can be avoided. As a result, it is possible to suppress a reduction in the contact area between the outer conductive ribbon 17ae and the laser diode element 16.

[0077] In FIG. 22, a configuration is shown in which a ribbon-shaped corrugated structure portion is formed by overlapping two conductive ribbons 17ae and 17af with different lengths, but a configuration in which three or more conductive ribbons 17a with different lengths are overlapped may also be used. Also, the thickness of the inner conductive ribbon 17af may be made thicker than the thickness of the outer conductive ribbon 17ae. As a result, the inner conductive ribbon 17af becomes less likely to deform, and it becomes possible to avoid buckling of the outer conductive ribbon 17ae.

[0078] A plurality of ribbon-shaped corrugated structure portions formed by such a plurality of conductive ribbons 17ae and 17af with different lengths may be arranged in parallel between the laser diode element 16 and the cathode electrode 14 as shown in FIG. 23. Also, as shown in FIGS. 22 and 23, the positions of the tops 171ae and 171af of the waveforms or the bonding portions 173 of the plurality of conductive ribbons 17ae and 17af arranged in parallel may be the same in the extending direction of the ribbon-shaped corrugated structure portion, or may be at different positions as shown in FIG. 21. Also, the plurality of ribbon-shaped corrugated structure portions do not have to be parallel to each other as shown in FIG. 8.

[0079] The manufacturing method of the semiconductor laser module 10 having such a ribbon-shaped corrugated structure portion is the same as that described in Embodiment 1. However, when joining the ribbon-shaped corrugated structure portion to the cathode electrode 14, the inner conductive ribbon 17af is joined at the position of the bonding portion 173 of the flat surface 142a of the cathode electrode 14. Next, the outer conductive ribbon 17ae is joined so as to overlap the inner conductive ribbon 17af at the position of the bonding portion 173. As a result, as shown in FIG. 22, the ribbon-shaped corrugated structure portion is joined to the flat surface 142a of the cathode electrode 14.

[0080] In Embodiment 3, the ribbon-shaped corrugated structure portion has a configuration in which a plurality of conductive ribbons 17ae and 17af having different waveforms and lengths are overlapped. As a result, when assembling the electrode structure 25 and the heat sink 11, even if the ribbon-shaped corrugated structure portion comes into contact with the laser diode element 16 and deforms, and the outer conductive ribbon 17ae is likely to buckle, the inner conductive ribbon 17af presses the vicinity of the top 171ae of the outer conductive ribbon 17ae, thereby avoiding buckling of the outer conductive ribbon 17ae. In one example, even when the dimension in the Y-axis direction of the gap 172 of the outer conductive ribbon 17ae in the state shown in FIG. 10 after assembly shown in Embodiment 1 becomes shorter than about 130 μm, buckling of the outer conductive ribbon 17ae can be avoided. Therefore, a decrease in the contact area between the outer conductive ribbon 17ae and the laser diode element 16 can be suppressed. As a result, a decrease in the long-term reliability of the laser diode element 16 can be suppressed. In addition, a semiconductor laser module 10 with improved contact between the ribbon-shaped corrugated structure portion and the laser diode element 16 can be obtained without worrying about the distance between the assembled laser diode element 16 and the flat surface 142a of the cathode electrode 14.

[0081] Embodiment 4. The semiconductor laser module 10 described in Embodiments 1 to 3 can be used as a light source of a laser processing apparatus. FIG. 24 is a diagram schematically showing an example of the configuration of a laser processing apparatus according to Embodiment 4. The laser processing apparatus 300 includes a laser oscillator 310, an optical fiber 320, and a processing head 330.

[0082] The laser oscillator 310 emits laser light. FIG. 25 is a diagram schematically showing an example of the configuration of a laser oscillator used in the laser processing apparatus according to Embodiment 4. The laser oscillator 310 includes a plurality of semiconductor laser modules 10, an optical coupling unit 311, and an external resonance mirror 312. The semiconductor laser module 10 has the structure described in Embodiments 1 to 3. The optical coupling unit 311 couples the laser light L from the plurality of semiconductor laser modules 10. As the optical coupling unit 311, a prism, a diffraction grating, or the like is used. The external resonance mirror 312 transmits a part of the laser light Lx coupled by the optical coupling unit 311 and reflects the remaining part back to the semiconductor laser module 10 side. The external resonance mirror 312 forms an optical resonator with the emission surface of the laser light L in the laser diode element 16 of the semiconductor laser module 10.

[0083] Returning to FIG. 24, the optical fiber 320 transmits the combined laser light Lx emitted from the laser oscillator 310 to the processing head 330.

[0084] The processing head 330 condenses the laser light Lx transmitted through the optical fiber 320 and irradiates the workpiece. The processing head 330 includes a condensing optical system that condenses the laser light Lx transmitted through the optical fiber 320 and irradiates the workpiece. During processing, the processing head 330 is arranged to face the position on the workpiece to be processed.

[0085] In the laser processing apparatus 300 according to the fourth embodiment, in the semiconductor laser module 10, a ribbon-shaped corrugated structure portion is disposed between the laser diode element 16 and the cathode electrode 14 to enhance both electrical conductivity and thermal conductivity. In this configuration, since the ribbon-shaped corrugated structure portion is easily deformed, when the semiconductor laser module 10 is assembled, the stress applied to the laser diode element 16 by the power supply structure 17 is reduced as compared with the case of the bump, and a decrease in the long-term reliability of the laser diode element 16 can be suppressed. As a result, there is an effect that a laser processing apparatus 300 in which a decrease in the long-term reliability of the laser diode element 16 is suppressed can be obtained.

[0086] The configurations shown in the above embodiments are merely examples, and it is possible to combine them with other known technologies, to combine the embodiments with each other, and to omit or change a part of the configuration without departing from the gist.

[0087] Hereinafter, aspects of the present disclosure will be collectively described as appendices.

[0088] [Appendix 1] A heat sink, A first electrode disposed in a first region of the heat sink, An insulating layer disposed on the first electrode, A submount disposed in a second region different from the first region of the heat sink and having electrical conductivity and thermal conductivity, A laser diode element disposed on the submount and emitting laser light, A power supply structure disposed on the laser diode element and having electrical conductivity, thermal conductivity, and elasticity, A second electrode provided so as to be in contact with the insulating layer and the power supply structure, Comprising The second electrode has an electrode facing portion having a flat surface in contact with the insulating layer, and a convex portion having a flat surface in contact with the power supply structure and protruding toward the heat sink side from the electrode facing portion. The power supply structure is characterized in that it is constituted by a ribbon-shaped corrugated structure portion disposed between the laser diode element and the second electrode, in a semiconductor laser module. [Appendix 2] The semiconductor laser module according to Appendix 1, wherein the power supply structure is constituted by a plurality of the ribbon-shaped corrugated structure portions. [Appendix 3] The semiconductor laser module according to Appendix 2, wherein the plurality of the ribbon-shaped corrugated structure portions are arranged in parallel in a defined direction. [Appendix 4] The ribbon-shaped corrugated structure portion is joined to the second electrode at a bonding portion which is a defined position so as to be corrugated, The semiconductor laser module according to Appendix 2 or 3, wherein the positions of the bonding portions of all the ribbon-shaped corrugated structure portions are the same in the extending direction of the ribbon-shaped corrugated structure portion. [Appendix 5] The ribbon-shaped corrugated structure portion is joined to the second electrode at a bonding portion which is a defined position so as to be corrugated, The semiconductor laser module according to Appendix 2 or 3, wherein the positions of the bonding portions of all the ribbon-shaped corrugated structure portions are not the same in the extending direction of the ribbon-shaped corrugated structure portion. [Appendix 6] The ribbon-shaped corrugated structure portion is joined to the second electrode at a bonding portion which is a defined position so as to be corrugated, The semiconductor laser module according to Appendix 2 or 3, wherein the positions of the bonding portions of two adjacent ribbon-shaped corrugated structure portions in a direction intersecting the extending direction of the ribbon-shaped corrugated structure portion are different in the extending direction. [Appendix 7] The semiconductor laser module according to any one of Appendices 1 to 6, wherein the ribbon-shaped corrugated structure portion is constituted by one conductive ribbon. [Appendix 8] The semiconductor laser module according to any one of Appendices 1 to 6, characterized in that the ribbon-shaped corrugated structure portion has a configuration in which a plurality of conductive ribbons having different lengths are stacked. [Appendix 9] A laser oscillator having a plurality of semiconductor laser modules according to any one of Appendices 1 to 8, and combining and emitting the laser light emitted from the plurality of semiconductor laser modules; An optical fiber for transmitting the combined laser light emitted from the laser oscillator; A processing head that condenses the combined laser light from the optical fiber and irradiates the workpiece; A laser processing apparatus characterized by comprising: [Appendix 10] A step of joining an insulating layer to the electrode facing portion of the second electrode having an electrode facing portion having a flat surface facing the first electrode and a convex portion protruding in a direction perpendicular to the flat surface of the electrode facing portion and having a flat surface; A step of joining the first electrode to the electrode facing portion of the second electrode via the insulating layer; A step of joining a power supply structure having conductivity, thermal conductivity, and elasticity to the convex portion of the second electrode to form an electrode structure; A step of joining a laser diode element that emits laser light onto a submount having conductivity and thermal conductivity; A step of joining the submount to the element arrangement region of the heat sink; A step of joining the electrode structure and the heat sink so that the laser diode element and the power supply structure face each other, and the electrode arrangement region, which is a region different from the element arrangement region of the heat sink, and the first electrode face each other; Including A method for manufacturing a semiconductor laser module, characterized in that the power supply structure is constituted by a ribbon-shaped corrugated structure portion disposed between the laser diode element and the second electrode.

Description of Reference Numerals

[0089] 10 Semiconductor laser module, 11 Heat sink, 12 Anode electrode, 13 Insulating sheet, 14 Cathode electrode, 15 Submount, 16,516 Laser diode element, 17 Power supply structure, 17a,17aa,17ab,17ac,17ad,17ae,17af Conductive ribbon, 20 Laser emission section, 25 Electrode structure, 31 FAC, 32 SAC, 33 Manifold, 35,36,201 Adhesive, 121 First part, 122 Second part, 122a Lower surface, 141 Electrode facing part, 142 Convex part, 142a Flat surface, 171,171ac,171ad,171ae,171af Top, 172 Gap, 173,173ac,173ad Bonding part, 202 Conductive adhesive, 300 Laser processing apparatus, 310 Laser oscillator, 311 Optical coupling part, 312 External resonance mirror, 320 Optical fiber, 330 Processing head, 514 Upper electrode block, 517 Bump, L,Lx Laser light, R1 Electrode arrangement region, R2 Element arrangement region.

Claims

1. A heat sink, a first electrode disposed in a first region of the heat sink, an insulating layer disposed on the first electrode, a submount disposed in a second region different from the first region of the heat sink and having conductivity and thermal conductivity, a laser diode element disposed on the submount and emitting laser light, a power supply structure disposed on the laser diode element and having conductivity, thermal conductivity, and elasticity, a second electrode provided so as to be in contact with the insulating layer and the power supply structure, comprising: The second electrode has an electrode facing portion having a flat surface in contact with the insulating layer, and a convex portion having a flat surface in contact with the power supply structure and protruding toward the heat sink side from the electrode facing portion. The semiconductor laser module, wherein the power supply structure is constituted by a ribbon-shaped corrugated structure portion disposed between the laser diode element and the second electrode.

2. The semiconductor laser module according to claim 1, wherein the power supply structure is constituted by a plurality of the ribbon-shaped corrugated structure portions.

3. The semiconductor laser module according to claim 2, wherein the plurality of the ribbon-shaped corrugated structure portions are arranged in parallel in a defined direction.

4. The ribbon-shaped corrugated structure portion is joined to the second electrode at a bonding portion which is a defined position so as to be corrugated, The semiconductor laser module according to claim 3, wherein positions of the bonding portions of all the ribbon-shaped corrugated structure portions are the same in the extending direction of the ribbon-shaped corrugated structure portion.

5. The ribbon-shaped corrugated structure portion is joined to the second electrode at a bonding portion which is a defined position so as to be corrugated, The semiconductor laser module according to claim 3, wherein positions of the bonding portions of all the ribbon-shaped corrugated structure portions are not the same in the extending direction of the ribbon-shaped corrugated structure portion.

6. The ribbon-shaped corrugated structure portion is joined to the second electrode at a bonding portion which is a defined position so as to be corrugated, The semiconductor laser module according to claim 3, wherein positions of the bonding portions of two adjacent ribbon-shaped corrugated structure portions in a direction intersecting the extending direction of the ribbon-shaped corrugated structure portion are different in the extending direction.

7. The semiconductor laser module according to claim 1, wherein the ribbon-shaped corrugated structure portion is composed of one conductive ribbon.

8. The semiconductor laser module according to claim 1, wherein the ribbon-shaped corrugated structure portion has a structure in which a plurality of conductive ribbons having different lengths are stacked.

9. A laser oscillator having a plurality of the semiconductor laser modules according to any one of claims 1 to 8, and combining and emitting the laser light emitted from the plurality of semiconductor laser modules; An optical fiber for transmitting the combined laser light emitted from the laser oscillator; A processing head that condenses the combined laser light from the optical fiber and irradiates a workpiece; A laser processing apparatus, characterized by comprising:

10. A step of bonding an insulating layer to the electrode facing portion of the second electrode, the electrode facing portion having a flat surface facing the first electrode, and a convex portion protruding in a direction perpendicular to the flat surface of the electrode facing portion and having a flat surface; A step of bonding the first electrode to the electrode facing portion of the second electrode via the insulating layer; A step of bonding a power supply structure having conductivity, heat conductivity, and elasticity to the convex portion of the second electrode to form an electrode structure; A step of bonding a laser diode element that emits laser light onto a submount having conductivity and heat conductivity; A step of bonding the submount to an element arrangement region of a heat sink; A step of bonding the electrode structure and the heat sink so that the laser diode element and the power supply structure face each other, and the electrode arrangement region, which is a region different from the element arrangement region of the heat sink, and the first electrode face each other; Including A method for manufacturing a semiconductor laser module, wherein the power supply structure is composed of a ribbon-shaped corrugated structure portion disposed between the laser diode element and the second electrode.

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