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

Abstract

To provide a semiconductor laser module in which the variation in deformation caused by the location of a power supply structure between an upper electrode block and a laser diode element can be restrained more than ever before.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 disposed in the second region of the heat sink, a laser diode element disposed on the sub-mount, a corrugated conductive ribbon disposed on the laser diode element, and a second electrode provided on the insulating layer and the power supply structure. The insulating layer is configured by one member. On a surface facing the first electrode, the parallelism between a flat surface of a convex portion and the surface of the insulating layer on the first electrode side is within 0.03°. On a surface facing the heat sink, the parallelism between the flat surface of the convex portion and the surface of the first electrode on the heat sink side is within 0.03°.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 a high-power laser device typified by a light source for a laser processing apparatus, high-output light is obtained by optically coupling the oscillation lights from a plurality of semiconductor laser modules. In order to obtain further output, either increasing the number of semiconductor laser modules or increasing the output of each semiconductor laser module is adopted. 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. Since increasing the output of the semiconductor laser module is accompanied by an increase in the amount of heat generation, there are problems in 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 including a lower electrode block having a recess in a part of an upper surface, an insulating layer provided on the upper surface other than the recess of the lower electrode block, an upper electrode block disposed on the insulating layer, a submount disposed on the upper surface of the 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 fastening the lower electrode block and the upper electrode block. Further, the depth of the 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. Thereby, the bump is deformed, 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. 2016 / 103536 Summary of the Invention Problems to be Solved by the Invention

[0005] However, according to the above conventional technology, the insulating layer is composed of two insulating layers: a first insulating layer disposed on the upper surface so as to surround the recess of the lower electrode block, and a second insulating layer provided on the upper surface of the lower electrode block where the first insulating layer is not disposed. If the thicknesses of the two insulating layers are not the same and there are variations, a step will occur between the two insulating layers. When the upper electrode block is attached to the two insulating layers with a step, the upper electrode block will tilt. In the above conventional technology, since such variations in the thicknesses of the two insulating layers are not considered, a tilt will occur between the surface of the upper electrode block facing the laser diode element and the upper surface of the laser diode element. When this tilt occurs, the deformation of the bump, which is a power supply structure between the upper electrode block and the laser diode element, varies depending on the location, and there is a problem that variations in the contact area between the bump and the upper electrode block occur depending on the location.

[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 variations in deformation depending on the location of a power supply structure between an upper electrode block and a laser diode element as compared with the prior art. 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 corrugated conductive ribbon disposed between the laser diode element and the second electrode. The insulating layer is constituted by one member. The parallelism between the flat surface of the convex portion and the surface of the insulating layer on the first electrode side is within 0.03° on the surface of the second electrode and the insulating layer joined to the second electrode facing the first electrode. The parallelism between the flat surface of the convex portion and the surface of the first electrode on the heat sink side is within 0.03° on the surface of the second electrode and the first electrode joined to the second electrode via the insulating layer facing the heat sink.

Effect of the Invention

[0008] According to the present disclosure, there is an effect that variations in deformation due to the location of the power supply structure between the upper electrode block and the laser diode element can be suppressed as compared with the prior art.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Figure 17

Figure 18

Figure 19

Figure 20

Figure 21

Figure 22

Figure 23

Figure 24

Embodiments for Carrying Out the Invention

[0010] Hereinafter, a semiconductor laser module, a method for manufacturing the same, and a laser processing apparatus according to 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 a semiconductor laser module according to Embodiment 1. FIG. 2 is a partial cross-sectional view schematically showing an example of the configuration of a semiconductor laser module according to Embodiment 1. FIG. 3 is a front view schematically showing an example of the configuration of a 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, it is assumed that the front side is the side where the laser diode element 16 is provided on the 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. The heat sink 11 has a through hole (not shown) at the position of the electrode arrangement region R1 corresponding to the through hole 145 of the cathode electrode 14 described later. The through hole of the heat sink 11 penetrates the heat sink 11 in the thickness direction, more specifically, in the Y-axis direction which is the stacking direction of the members constituting the semiconductor laser module 10.

[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. The anode electrode 12 has a through hole (not shown) at the position of the second portion 122 corresponding to the through hole 145 of the cathode electrode 14 described later. The through hole of the anode electrode 12 penetrates the second portion 122 of the anode electrode 12 in the thickness direction, more specifically, in the Y-axis direction which is the stacking direction of the members constituting the semiconductor laser module 10.

[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 the surface. In this example, the cathode electrode 14 corresponds to the second electrode.

[0016] The cathode electrode 14 has a through hole 145 penetrating in the Y-axis direction. In one example, the side surface forming the through hole 145 is not threaded. The through hole 145 is used when assembling the semiconductor laser module 10. Further, the through hole 145 is also used when fixing the joined body of the cathode electrode 14, the insulating sheet 13, the anode electrode 12, and the heat sink 11 to a manifold 33 described later. The through hole 145 of the cathode electrode 14 penetrates the cathode electrode 14 in the thickness direction, more specifically, in the Y-axis direction which is the stacking direction of the members constituting the semiconductor laser module 10.

[0017] The insulating sheet 13 is an insulating layer disposed on the second portion 122 of the anode electrode 12 and provided to insulate the anode electrode 12 and the cathode electrode 14. The insulating sheet 13 has a through hole (not shown) at a position corresponding to the through hole 145 of the cathode electrode 14. The through hole of the insulating sheet 13 penetrates the insulating sheet 13 in the thickness direction, more specifically, in the Y-axis direction which is the stacking direction of the members constituting the semiconductor laser module 10.

[0018] In the element arrangement region R2 of the heat sink 11, a laser diode element 16 is arranged via a 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 coefficients 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 has thermal conductivity in order to transfer the heat from the laser diode element 16 to the heat sink 11, and it is desirable for the submount 15 to have conductivity in order 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).

[0019] The laser diode element 16 is arranged and fixed on the submount 15. The laser diode element 16 is an end-face emitting laser having a PN junction parallel to the ZX plane and emitting laser light L in the Z-axis direction. In one example, the laser diode element 16 uses gallium arsenide (GaAs) as a substrate and indium gallium arsenide (InGaAs) as an 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.

[0020] 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 amount of heat exhausted 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.

[0021] 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.

[0022] The anode electrode 12 is electrically connected to the laser diode element 16 via the heat sink 11 and the submount 15. The cathode electrode 14 is electrically connected to the laser diode element 16 via the power supply structure 17.

[0023] In the above description, the case where the heat sink 11 has conductivity is shown, but the heat sink 11 may partly 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.

[0024] 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.

[0025] Also, the semiconductor laser module 10 includes a Fast Axis Collimator (FAC) 31, an SAC 32, and a manifold 33.

[0026] FAC31 is an optical component provided on the end face of the laser diode element 16 of the laser emission unit 20 in the Z-axis direction, and collimates the fast-axis direction component of the laser beam L emitted from the laser diode element 16. In one example, FAC31 is fixed to the end face of the heat sink 11 in the Z-axis direction by an adhesive 35.

[0027] SAC32 is an optical component that collimates the slow-axis direction component of the laser beam L that has passed through FAC31. SAC32 is arranged at a distance from FAC31.

[0028] 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. Thread holes (not shown) are provided on the surface of the manifold 33 that supports the heat sink 11, that is, the surface where the laser emission unit 20 is arranged. The thread holes are provided at positions corresponding to the through holes 145 of the cathode electrode 14 when the laser emission unit 20 and the manifold 33 are assembled. In one example, the thread holes have bottoms in the middle of the Y-axis direction, which is the thickness direction of the manifold 33. The laser emission unit 20 is positioned and arranged on the upper surface of the manifold 33, and a screw 55, which is an example of a fastening member, is inserted through from the upper surface of the cathode electrode 14 and screwed into the thread holes, thereby fixing the laser emission unit 20 to the manifold 33.

[0029] Also, 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 in the manifold 33. The water channel in 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.

[0030] The end of the manifold 33 in the Z-axis direction protrudes in the emission direction of the laser beam L beyond the end of the laser emission section 20 on the manifold 33 in the Z-axis direction. The SAC 32 is fixed to this end with an adhesive 36. In FIG. 1, an example is shown in which the laser emission section 20, the FAC 31, and the SAC 32 are integrated on the manifold 33, but the SAC 32 may be provided separately from the laser emission section 20 and the FAC 31.

[0031] 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 perpendicular to the heat sink 11 side or the flat surface of the electrode facing portion 141 as compared with the electrode facing portion 141.

[0032] In a state where the cathode electrode 14 is not arranged, the value obtained by subtracting the height h of the convex portion 142 from the sum of the thicknesses of the insulating sheet 13 and the anode electrode 12 is made smaller than the sum of the thicknesses of the submount 15, the laser diode element 16, and the power supply structure 17. Thereby, when the cathode electrode 14 is arranged to form the structure of the laser emission section 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.

[0033] 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.

[0034] Here, the structure of the power supply structure 17 will be described. The power supply structure 17 according to Embodiment 1 preferably has the following four requirements. (1) In the heat cycle for switching between energization and non-energization of 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 with 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.

[0035] Note that when using something like solder as the power supply structure 17, it may melt in the high-temperature range and bond with the gold plating on the surface of the laser diode element 16. In this case, the power supply structure 17 having the requirement shown in (2) above bonds with the gold plating on the surface of the laser diode element 16, resulting in stress being likely to occur at the bonding portion and not satisfying the condition of (1) above.

[0036] As a material for the power supply structure 17 that satisfies the above (1) to (4), a conductive ribbon with a thickness of several tens of μm can be used. The conductive ribbon is a member having a corrugated structure disposed between the laser diode element 16 and the cathode electrode 14. An example of the conductive ribbon is a gold ribbon or a copper ribbon. FIG. 5 is a diagram 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 where the semiconductor laser module 10 is not completely assembled, that is, a state where the conductive ribbon 17a is not deformed. As shown in FIG. 5, the conductive ribbon 17a is corrugated and bonded to the convex portion 142 of the cathode electrode 14. In a state where the semiconductor laser module 10 is not assembled, the corrugated top portion 171 of the conductive ribbon 17a is in contact with the upper surface of the laser diode element 16. There are gaps 172 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 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. The two surfaces of the conductive ribbon 17a are arranged 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 diagram showing an example of the shape of the ribbon before assembly of the semiconductor laser module according to Embodiment 1. As shown in FIG. 6, the conductive ribbon 17a has a corrugated shape, and the top of the conductive ribbon 17a on the cathode electrode 14 side is bonded to the flat surface 142a of the convex portion 142 of the cathode electrode 14 at a constant interval, thereby being fixed to the cathode electrode 14. That is, the portion of the top of the conductive ribbon 17a that is fixed to the flat surface 142a of the cathode electrode 14 becomes the bonding portion 173. In this way, the conductive ribbon 17a is joined to the cathode electrode 14 at the bonding portion 173, which is a defined position, so as to have a corrugated shape. An example of the method of fixing the conductive ribbon 17a and the flat surface 142a at the bonding portion 173 is ultrasonic bonding or the like.

[0038] FIG. 7 is a diagram showing an example of the shape of the ribbon after 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 corrugated top 171 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. 7. The dashed line A in FIG. 7 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.

[0039] FIG. 8 is a diagram showing an example of the shape of the ribbon after the 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. 8, 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. 7, 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 dimensional value in the Y-axis direction of the gap 172 in the state shown in FIG. 7 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 a part of the top 171 is adjusted so as not to lift off from the laser diode element 16 as shown in FIG. 7 for the shape of the conductive ribbon 17a after assembly. The broken line A in FIG. 8 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.

[0040] 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.

[0041] In this state, by disposing the cathode electrode 14, the conductive ribbon 17a will be elastically deformed in accordance with the thicknesses of the anode electrode 12 and the insulating sheet 13 in the electrode arrangement region R1. FIG. 9 is a diagram showing an example of the structure of the conductive ribbon of the semiconductor laser module according to Embodiment 1. FIG. 9 shows a state in which the semiconductor laser module 10 is assembled. As shown in FIG. 9, the top 171 of the conductive ribbon 17a on the laser diode element 16 side is crushed. The broken line A in FIG. 9 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 becomes 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.

[0042] Further, 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 has reached the cathode electrode 14 diffuses along a plane at 45° 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, the heat diffuses within the cathode electrode 14 along a plane at an angle of 45° from the contact portion of the conductive ribbon 17a, and finally, the heat is exhausted to the heat sink 11 via the insulating sheet 13 and the anode electrode 12, whereby the heat from the laser diode element 16 is exhausted.

[0043] In FIG. 9, 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 not satisfied. By touching the conductive ribbon 17a to the laser diode element 16 without completely joining it as shown in FIG. 9, 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 can be enhanced through the conductive ribbon 17a without generating stress between the conductive ribbon 17a and the laser diode element 16.

[0044] In the conductive ribbon 17a, as shown in FIG. 6, a plurality of peaks having a top 171 on the negative side in the Y-axis direction are arranged in the extending direction of the conductive ribbon 17a. Among the plurality of peaks of the conductive ribbon 17a, it is possible that one peak buckles as shown in FIG. 8 and the other peaks contact the laser diode element 16 as desired as shown in FIG. 7. In such a case, the contact area with the laser diode element 16 is smaller at the buckled peak than at the other peaks, and variation in the contact area occurs among the plurality of peaks. When variation in the contact area occurs, concentration of the current flowing from the laser diode element 16 to the cathode electrode 14 occurs toward the peak having a larger contact area. When such current concentration occurs, a load is applied to the laser diode element 16, which is not desirable. Therefore, it has been desired to make the contact area uniform at all the peaks. That is, it has been desired to accurately control the amount of crushing at all the tops 171 of the conductive ribbon 17a to a certain extent.

[0045] The variation in the contact area of the peaks in such a conductive ribbon 17a is due to the variation caused by the position of the gap 172 between the laser diode element 16 and the cathode electrode 14. More specifically, it is because the inclination of the flat surface 142a of the convex portion 142 of the cathode electrode 14 facing the laser diode element 16 and the inclination of the upper surface of the laser diode element 16 are not parallel and are inclined.

[0046] In one example, in Patent Document 1, which is a conventional technique, a first insulating layer is disposed on the upper surface other than the concave portion so as to surround the concave portion of the lower electrode block, and a second insulating layer is disposed on the upper surface other than the concave portion of the lower electrode block where the first insulating layer is not disposed, and an upper electrode block is attached on the first insulating layer and the second insulating layer. When the thickness of the first insulating layer and the thickness of the second insulating layer are not the same and there is a variation between the thicknesses of the two, a step will occur between the two insulating layers. When the upper electrode block is attached on the two insulating layers with a step, the upper electrode block will tilt. As a result, there is a problem that an inclination occurs between the surface of the upper electrode block facing the laser diode element and the upper surface of the laser diode element.

[0047] That is, it is desired to make the gap 172 between the laser diode element 16 and the cathode electrode 14 uniform over the entire surface. For this reason, it is required to maintain a higher precision in the parallelism between the flat surface 142a of the cathode electrode 14 facing the laser diode element 16 and the surface of the laser diode element 16 facing the cathode electrode 14 than in the prior art.

[0048] In the conventional technique, it is considered that one of the causes of the step, that is, one of the reasons why the gap between the laser diode element and the upper electrode block cannot be made uniform over the entire surface, is that two insulating layers composed of a first insulating layer and a second insulating layer are disposed between the lower electrode block and the upper electrode block. Therefore, in Embodiment 1, the insulating sheet 13 disposed between the anode electrode 12 corresponding to the lower electrode block and the cathode electrode 14 corresponding to the upper electrode block is characterized in that it is composed of one member.

[0049] In the conventional technology, the parallelism between two surfaces of a member sandwiched between the lower electrode block and the upper electrode block in the assembled state is not considered. This is because in the conventional technology, it is assumed that the surface on which the laser diode element of the concave portion of the lower electrode block is disposed and the surface constituting the member sandwiched between the lower electrode block and the upper electrode block are parallel. However, in the manufacturing process of manufacturing an actual member, it is difficult to manufacture members having exactly the same dimensions and shapes, and manufacturing errors almost always occur. It is rare for two surfaces of one member to be parallel. For this reason, not considering the parallelism between two surfaces of the member sandwiched between the lower electrode block and the upper electrode block is also considered to be one of the reasons why the gap between the laser diode element and the upper electrode block cannot be made uniform over the entire surface. Therefore, in Embodiment 1, it is characterized in that the parallelism between two surfaces of the member sandwiched between the flat surface 142a, which is the surface facing the laser diode element 16 of the cathode electrode 14 in the assembled state, and the heat sink 11 is within a defined range. More specifically, it is characterized in that the parallelism between the flat surface 142a of the convex portion 142 and the flat surface of the electrode facing portion 141, which are two surfaces on the cathode electrode 14 side facing the heat sink 11, and the flat surface 142a of the convex portion 142 and the lower surface of the insulating sheet 13 is within a defined range.

[0050] In Embodiment 1, the parallelism between the flat surface 142a, which is the surface facing the laser diode element 16 of the cathode electrode 14 in the assembled state, and the surface of the member sandwiched between the cathode electrode 14 and the heat sink 11 is within a defined range.

[0051] Specifically, on the surface of the cathode electrode 14 facing the anode electrode 12, the cathode electrode 14 and the insulating sheet 13 joined to the cathode electrode 14 are selected such that the parallelism between the flat surface 142a of the convex portion 142 of the cathode electrode 14 and the surface of the insulating sheet 13 facing the anode electrode 12 is within 0.03°. The parallelism between the flat surface 142a of the convex portion 142 of the cathode electrode 14 and the surface of the insulating sheet 13 facing the anode electrode 12 can also be regarded as the parallelism of the surface of the insulating sheet 13 facing the anode electrode 12 with respect to the flat surface 142a of the cathode electrode 14. In this specification, the absolute value is used for the parallelism between the flat surface 142a of the convex portion 142 of the cathode electrode 14 and the surface of the insulating sheet 13 facing the anode electrode 12.

[0052] Also, on the surface of the cathode electrode 14 facing the heat sink 11, the cathode electrode 14 and the anode electrode 12 joined to the cathode electrode 14 via the insulating sheet 13 are selected such that the parallelism between the flat surface 142a of the convex portion 142 of the cathode electrode 14 and the surface of the anode electrode 12 facing the heat sink 11 is within 0.03°. The parallelism between the flat surface 142a of the convex portion 142 of the cathode electrode 14 and the surface of the anode electrode 12 facing the heat sink 11 can also be regarded as the parallelism of the surface of the anode electrode 12 facing the heat sink 11 with respect to the flat surface 142a of the cathode electrode 14.

[0053] In this way, by making the parallelism between two surfaces of the member sandwiched between the convex portion 142 facing the laser diode element 16 of the cathode electrode 14 and the heat sink 11 within 0.03°, the gap 172 between the laser diode element 16 and the cathode electrode 14 can be made uniform over the entire surface. The fact that the gap 172 becomes uniform means that the ridges of the conductive ribbon 17a between the laser diode element 16 and the flat surface 142a of the cathode electrode 14 receive the same stress regardless of the position on the laser diode element 16. As a result, the amount of crushing of the ridges of the conductive ribbon 17a can be made uniform over the entire surface of the laser diode element 16. And the contact area of the conductive ribbon 17a with the laser diode element 16 becomes corresponding to the amount of crushing of the ridges of the conductive ribbon 17a, and the contact area can also be made uniform over the entire surface of the laser diode element 16.

[0054] Note that the flatness of the surfaces of the individual members of the cathode electrode 14, the insulating sheet 13, and the anode electrode 12 that come into contact with other members may also affect the gap 172 between the laser diode element 16 and the cathode electrode 14. That is, when there are irregularities on the members, these irregularities inhibit the uniformity of the gap 172 between the laser diode element 16 and the cathode electrode 14. For this reason, it is desirable to measure the flatness of each of the individual members of the cathode electrode 14, the insulating sheet 13, and the anode electrode 12 and use those within a defined range of flatness. In one example, the defined range of flatness is within 30 μm. By doing so, the gap 172 between the laser diode element 16 and the cathode electrode 14 can be made even more uniform over the entire upper surface of the laser diode element 16. However, the influence of the flatness of each of the individual members of the cathode electrode 14, the insulating sheet 13, and the anode electrode 12 on the uniformity of the gap 172 between the laser diode element 16 and the cathode electrode 14 is smaller compared to setting the parallelism between two surfaces of the member sandwiched between the flat surface 142a of the convex portion 142 of the cathode electrode 14 and the heat sink 11 within a defined range. For this reason, the measurement of the flatness of each of the individual members of the cathode electrode 14, the insulating sheet 13, and the anode electrode 12 may be omitted.

[0055] Also, the parallelism of each of the individual members of the cathode electrode 14, the insulating sheet 13, and the second portion 122 of the anode electrode 12 may be measured. However, as long as the parallelism between two surfaces of the member sandwiched between the flat surface 142a of the convex portion 142 of the cathode electrode 14 and the heat sink 11 after assembly can be made within a defined range, the measurement of the parallelism of each of the individual members of the cathode electrode 14, the insulating sheet 13, and the second portion 122 of the anode electrode 12 may be omitted.

[0056] Next, a method for manufacturing the semiconductor laser module 10 with such a configuration will be described. FIGS. 10 to 22 are diagrams 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 related to 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. 10 to 22, 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. 10 to 22, it is referred to as the lower surface.

[0057] First, as shown in FIG. 10, a cathode electrode 14 and an insulating sheet 13 are prepared. The cathode electrode 14 is placed on a base plate (not shown) with a cut tap such that the flat surface 142a of the convex portion 142 faces upward in FIG. 10. Next, as shown in FIG. 11, the insulating sheet 13 is placed on the electrode facing portion 141 of the cathode electrode 14. Then, the positions of the through holes 135 of the insulating sheet 13 and the through holes 145 of the cathode electrode 14 are aligned with the position of the tap of the base plate (not shown), and a screw 55, which is an example of a fastening member, is inserted through the through holes 145 and 135 provided in the cathode electrode 14 and the insulating sheet 13 and screwed into the tap of the base plate to be fastened. As a result, the cathode electrode 14 and the insulating sheet 13 are temporarily fixed to the base plate. The cathode electrode 14 and the insulating sheet 13 temporarily fixed to the base plate are referred to as the first fastening body 61. The process shown in FIG. 11 corresponds to the first fastening step of fastening an insulating layer with a fastening member to the electrode facing portion 141 of the second electrode having the flat surface 141a facing the first electrode and the convex portion 142 protruding in a direction perpendicular to the flat surface 141a of the electrode facing portion 141 and having the flat surface 142a to form the first fastening body 61.

[0058] In this state, the parallelism between the flat surface 142a of the convex portion 142 of the cathode electrode 14 and the lower surface 13a of the insulating sheet 13 is measured. For measuring the parallelism, a laser displacement meter is used as an example. FIG. 12 shows an example of a method for measuring the parallelism between two surfaces of two members. The lower surface of the first fastening body 61 is such that the flat surface 142a of the convex portion 142 of the cathode electrode 14 and the lower surface 13a of the insulating sheet 13 are exposed. These flat surface 142a and the insulating sheet 13 are based on the base plate. Therefore, by placing the first fastening body 61 on the stage of the laser displacement meter, the positions of the flat surface 142a of the convex portion 142 of the cathode electrode 14 and the lower surface 13a of the insulating sheet 13 can be measured with reference to the upper surface of the stage of the laser displacement meter. The process shown in FIG. 12 corresponds to the first parallelism measurement step of measuring the parallelism of the first fastening body 61, which is the parallelism between the flat surface 142a of the convex portion 142 of the first fastening body 61 and the first surface on the opposite side of the surface in contact with the second electrode of the insulating layer. Also, the lower surface 13a of the insulating sheet 13 corresponds to the first surface.

[0059] In FIG. 12, two a-axes and b-axes orthogonal to each other are taken within the upper surface of the stage of the laser displacement meter, and a c-axis is taken such that it is perpendicular to both the a-axis and the b-axis and passes through the intersection of the a-axis and the b-axis. As an example, measurement points in the ab-plane between the flat surface 142a of the cathode electrode 14 and the lower surface 13a of the insulating sheet 13 are determined in advance, and the heights of the measurement points are measured. The height of the measurement point is, in this example, the position in the c-axis direction with reference to the upper surface of the stage of the laser displacement meter. Here, after measuring the flat surface 142a of the cathode electrode 14, the lower surface 13a of the insulating sheet 13 is measured. In the example of FIG. 12, for the flat surface 142a of the cathode electrode 14, measurements are made for 9 measurement points, and for the lower surface 13a of the insulating sheet 13, measurements are made for 40 measurement points. Also, a plurality of measurement points arranged in the a-axis direction are taken as one measurement unit, and the process of sequentially measuring the next measurement unit adjacent in the negative b-axis direction after the measurement of this measurement unit is completed is performed. Note that the number of measurement points shown here is an example and can be any number.

[0060] Using a laser displacement meter, the inclination of the flat surface 142a of the cathode electrode 14 is calculated from a plurality of measurement points on the flat surface 142a using a known calculation method. Also, using a laser displacement meter, the inclination of the lower surface 13a of the insulating sheet 13 is calculated from a plurality of measurement points on the lower surface 13a of the insulating sheet 13 using a known calculation method. Then, the relative angle between the two surfaces is calculated as the parallelism from the inclinations of the two calculated surfaces. The parallelism calculated here corresponds to the parallelism of the first fastening member 61.

[0061] As a result of the measurement, if the parallelism is not within 0.03°, it is assumed that the gap 172 between the assembled laser diode element 16 and the cathode electrode 14 cannot be made uniform over the entire surface with the combination of the measured cathode electrode 14 and the insulating sheet 13. Therefore, the combination of the temporarily fixed cathode electrode 14 and the insulating sheet 13 is discarded, and the process of FIG. 10, that is, the process of the first fastening step, is returned to. In one example, one of the members of the cathode electrode 14 and the insulating sheet 13 is replaced with another member and the process is restarted from the process of FIG. 10. Note that since one of the members to be replaced may be usable as a combination with the other member, it is desirable to store it without discarding it.

[0062] On the other hand, when the parallelism is within 0.03°, it is assumed that the size of the gap 172 between the assembled laser diode element 16 and the cathode electrode 14 can be made uniform over the entire surface with the combination of the measured cathode electrode 14 and the insulating sheet 13. Therefore, the fastening with the screw 55 is released, and the temporarily fixed cathode electrode 14 and the insulating sheet 13 are disassembled. As described above, the relative heights of a plurality of measurement points are measured on the flat surface 142a, which is the surface where the conductive ribbon 17a in the cathode electrode 14 is struck, and the lower surface 13a of the insulating sheet 13, which is the surface where the heat sink 11 is struck, the variation, that is, the inclination is measured, and the necessity of the combination of the cathode electrode 14 and the insulating sheet 13 is determined.

[0063] Next, as shown in FIG. 13, place the cathode electrode 14 on a base plate (not shown) with the tap cut such that the flat surface 142a of the convex portion 142 of the cathode electrode 14 faces upward in FIG. 13. Also, apply an adhesive 201 to the electrode facing portion 141 of the cathode electrode 14. The adhesive 201 used here is an insulating adhesive. Then, as shown in FIG. 14, place the insulating sheet 13 on the electrode facing portion 141 to which the adhesive 201 has been applied. Insert a screw 55, which is an example of a fastening member, through the through-hole 135 of the insulating sheet 13 and the through-hole 145 of the cathode electrode 14 from the side of the insulating sheet 13 and thread it into the tap of the base plate. As a result, as shown in FIG. 15, the insulating sheet 13 is joined and firmly fixed on the electrode facing portion 141 of the cathode electrode 14. The process shown in FIGS. 13 to 15 corresponds to a first joining step of joining an insulating layer to the electrode facing portion 141 of the second electrode via the adhesive 201 when the parallelism of the first fastening body 61 is within 0.03°.

[0064] At this time, a flat fastening plate (not shown) provided with through-holes may be placed on the insulating sheet 13, and the fastening plate, the insulating sheet 13, and the cathode electrode 14 may be fastened to the base plate using the screw 55 from the side of the fastening plate. Specifically, a flat fastening plate (not shown) having through-holes may be further placed on the insulating sheet 13, and the screw 55 may be inserted through the through-hole of the fastening plate, the through-hole 135 of the insulating sheet 13, and the through-hole 145 of the cathode electrode 14 and threaded into the tap of the base plate for fastening. Thereby, it is possible to press between the insulating sheet 13 and the cathode electrode 14 in parallel and uniformly. As a result, even if there are partial irregularities in the thickness of the applied adhesive 201, the insulating sheet 13 and the cathode electrode 14 can be joined so as to be parallel, and a state close to the state in which the parallelism is measured with the temporarily fixed first fastening body 61 can be achieved. The fastening plate is preferably a flat plate larger in size than the insulating sheet 13 in order to uniformly press the insulating sheet 13 during fastening with the screw 55.

[0065] After the joining is completed, the screw 55 is removed, and when using the fastening plate, the fastening plate is also removed. Next, the cathode electrode 14 is placed on the base plate. In this state, the anode electrode 12 is placed on the electrode facing portion 141 of the cathode electrode 14 via the insulating sheet 13 so that the upper surface of the second portion 122 of the anode electrode 12 contacts the insulating sheet 13 joined to the cathode electrode 14. As shown in FIG. 16, the positions of the through holes of the anode electrode 12, the through hole 135 of the insulating sheet 13, and the through hole 145 of the cathode electrode 14 are aligned with the positions of the taps on the base plate. Then, a screw 55, which is an example of a fastening member, is inserted through the through holes 125, 135, and 145 provided in the anode electrode 12, the insulating sheet 13, and the cathode electrode 14, and screwed into the taps on the base plate for fastening. As a result, the anode electrode 12 and the cathode electrode 14 joined with the insulating sheet 13 are temporarily fixed to the base plate. The anode electrode 12 and the cathode electrode 14 joined with the insulating sheet 13 that are temporarily fixed to the base plate are referred to as the second fastening body 62. The process shown in FIG. 16 corresponds to the second fastening process of fastening the first electrode to the electrode facing portion 141 of the second electrode with a fastening member via an insulating layer to form the second fastening body 62.

[0066] In this state, the parallelism between the flat surface 142a of the convex portion 142 of the cathode electrode 14 and the lower surface 122a of the second portion 122 of the anode electrode 12 is measured. The measurement of the parallelism is the same as that described in FIG. 12 and is performed using a laser displacement meter. In this case, as shown in FIG. 17, the lower surface of the second fastening member 62 exposes the flat surface 142a of the convex portion 142 of the cathode electrode 14 and the lower surface 122a of the second portion 122 of the anode electrode 12. These flat surfaces 142a and the lower surface 122a of the anode electrode 12 are based on the base plate. Therefore, by placing the second fastening member 62 on the stage of the laser displacement meter, the positions of the flat surface 142a of the convex portion 142 of the cathode electrode 14 and the lower surface 122a of the anode electrode 12 can be measured with reference to the upper surface of the stage of the laser displacement meter as the height reference. Then, using the laser displacement meter, the heights at nine measurement points on the flat surface 142a of the cathode electrode 14 and the heights at forty measurement points on the lower surface 122a of the anode electrode 12 are measured. Note that the number of measurement points is an example and can be any number. The process shown in FIG. 17 corresponds to a second parallelism measurement step of measuring the parallelism of the second fastening member 62, which is the parallelism between the flat surface 142a of the convex portion 142 of the second fastening member 62 and the second surface on the opposite side of the surface in contact with the insulating layer of the first electrode. Also, the lower surface 122a of the second portion 122 of the anode electrode 12 corresponds to the second surface.

[0067] Using a laser displacement meter, the inclination of the flat surface 142a is calculated from a plurality of measurement points on the flat surface 142a of the cathode electrode 14 using a known calculation method. Also, using a laser displacement meter, the inclination of the lower surface 122a of the anode electrode 12 is calculated from a plurality of measurement points on the lower surface 122a of the anode electrode 12 using a known calculation method. Then, the relative angle between the two surfaces is calculated as the parallelism from the inclinations of the two calculated surfaces. The parallelism calculated here corresponds to the parallelism of the second fastening member 62.

[0068] As a result of measurement, if the parallelism is not within 0.03°, in the combination of the cathode electrode 14 and the anode electrode 12 to which the measured insulating sheet 13 is joined, the gap 172 between the assembled laser diode element 16 and the cathode electrode 14 cannot be made uniform over the entire surface. Therefore, the combination of the cathode electrode 14 and the anode electrode 12 to which the temporarily fixed insulating sheet 13 is joined is discarded, and the process of FIG. 16, that is, the process of the second fastening step, is returned to. In one example, the anode electrode 12 can be replaced with another member and the process of FIG. 16 can be restarted. Note that the replaced anode electrode 12 may be used as a combination with the cathode electrode 14 to which another insulating sheet 13 is joined, so it is desirable to store it without discarding it.

[0069] On the other hand, if the parallelism is within 0.03°, the size of the gap 172 between the assembled laser diode element 16 and the cathode electrode 14 can be made uniform over the entire surface by the combination of the cathode electrode 14 and the anode electrode 12 to which the measured insulating sheet 13 is joined. Therefore, the fastening with the screw 55 is released, and the cathode electrode 14 and the anode electrode 12 to which the temporarily fixed insulating sheet 13 is joined are disassembled. As described above, on the flat surface 142a which is the surface where the conductive ribbon 17a in the cathode electrode 14 strikes, and the lower surface 122a of the second portion 122 of the anode electrode 12 which is the surface where the heat sink 11 strikes, the relative heights of a plurality of measurement points are measured, the variation, that is, the inclination is measured, and the necessity of the combination of the cathode electrode 14 and the anode electrode 12 to which the insulating sheet 13 is joined is determined.

[0070] Next, place the cathode electrode 14 with the insulating sheet 13 joined thereto on a base plate (not shown) where the tap has been cut so that the flat surface 142a of the convex portion 142 of the cathode electrode 14 faces upward. Apply an adhesive around the insulating sheet 13 of the electrode facing portion 141 of the cathode electrode 14. Here, an insulating adhesive is used as the adhesive used needs to insulate between the cathode electrode 14 and the anode electrode 12. Thereafter, as shown in FIG. 18, overlap the upper surface of the second portion 122 of the anode electrode 12 so as to contact the electrode facing portion 141 of the cathode electrode 14 with the insulating sheet 13 joined thereto, and place the anode electrode 12 on the cathode electrode 14 in FIG. 18. In this state, insert a screw (not shown) from the anode electrode 12 side through the through hole 125 of the second portion 122 of the anode electrode 12, the through hole 135 of the insulating sheet 13, and the through hole 145 of the cathode electrode 14, and thread it into the tap of the base plate. The state fastened by the screw is the same as that shown in FIG. 16. Thereby, the anode electrode 12 is joined and firmly fixed on the electrode facing portion 141 of the cathode electrode 14 via the insulating sheet 13. The process shown in FIG. 18 corresponds to the second joining process of joining the first electrode to the electrode facing portion 141 of the second electrode with the insulating layer joined thereto via an adhesive when the parallelism of the second fastening body 62 is within 0.03°.

[0071] At this time, the fastening plate may be placed on the anode electrode 12, and the fastening plate, the anode electrode 12, the insulating sheet 13, and the cathode electrode 14 may be fastened to the base plate using the screw 55 from the side of the fastening plate. Specifically, a flat fastening plate (not shown) having a through hole may be further placed on the anode electrode 12, and the screw 55 may be inserted through the through hole of the fastening plate, the through hole 125 of the anode electrode 12, the through hole 135 of the insulating sheet 13, and the through hole 145 of the cathode electrode 14 and screwed into the tap of the base plate for fastening. Thereby, the space between the anode electrode 12 and the cathode electrode 14 can be pushed parallelly and uniformly. As a result, even if there are partial irregularities in the thickness of the applied adhesive, the anode electrode 12 and the cathode electrode 14 can be joined so as to be parallel, and a state close to the state where the parallelism is measured by the temporarily fixed second fastening body 62 can be achieved. The fastening plate is preferably a flat plate having a size larger than that of the anode electrode 12 in order to uniformly press the anode electrode 12 during fastening with the screw 55.

[0072] After the joining is completed, the screw 55 is removed, and when a fastening plate is used, the fastening plate is also removed. Next, as shown in FIG. 19, a conductive ribbon 17a, which is a power supply structure 17, is joined to the flat surface 142a of the convex portion 142 of the cathode electrode 14. A plurality of conductive ribbons 17a 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. FIG. 19 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 are joined to 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 with 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. 19 corresponds to a power supply structure joining 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 an electrode structure 25. In the power supply structure joining process, the conductive ribbon 17a is joined in a corrugated shape as the power supply structure 17. And the electrode structure 25 is manufactured by the processes from FIG. 10 to FIG. 19 above.

[0073] In parallel with FIGS. 10 to 19, or before or after FIGS. 10 to 19, as shown in FIG. 20, 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 with a conductive adhesive. The process shown in FIG. 20 corresponds to an element joining process of joining a laser diode element 16 that emits laser light onto a submount 15 having conductivity and heat conductivity.

[0074] Furthermore, the submount 15 to which the laser diode element 16 is joined is joined to the element placement region R2 of the heat sink 11. The element placement region R2 is a region that faces the convex portion 142 of the cathode electrode 14 when the semiconductor laser module 10 is assembled. As a result, as shown in FIG. 21, a heat sink 11 to which the laser diode element 16 is joined is obtained. The process shown in FIG. 21 corresponds to the submount joining process of joining the submount 15 to the element placement region R2 of the heat sink 11.

[0075] Next, the electrode structure 25 manufactured in FIG. 19 and the heat sink 11 to which the laser diode element 16 manufactured in FIG. 21 is joined are joined. Specifically, the electrode structure 25 is placed on a base plate (not shown), and as shown in FIG. 22, 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. Thereafter, 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. 22. At this time, the heat sink 11 is placed on the anode electrode 12 while aligning the positions of the electrode structure 25 and the heat sink 11. Also, the heat sink 11 is inverted up and down from the state shown in FIG. 21 so that the laser diode element 16 faces the conductive ribbon 17a.

[0076] Thereafter, a screw 55 is inserted from the heat sink 11 side through the through holes 115 provided in the heat sink 11 and the through holes provided in the electrode structure 25, that is, the through hole 125 of the anode electrode 12, the through hole 135 of the insulating sheet 13, and the through hole 145 of the cathode electrode 14, and screwed into the tap of the base plate. As a result, the heat sink 11 is fastened to the electrode structure 25. Also, with the conductive ribbon 17a in contact with the laser diode element 16, the heat sink 11 is joined and firmly fixed to the anode electrode 12.

[0077] Since the height of the conductive ribbon 17a is 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, at this time, the top 171 of the conductive ribbon 17a is deformed so as to contact the upper surface of the laser diode element 16. Further, 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. The process shown in FIG. 22 corresponds to an electrode structure joining step of applying the conductive adhesive 202 to the first electrode, facing the power supply structure 17 and the laser diode element 16, and joining the electrode structure 25 and the heat sink 11 so that the electrode arrangement region R1, which is a region different from the element arrangement region R2 of the heat sink 11, faces the first electrode.

[0078] At this time, the fastening plate may be placed on the heat sink 11, and the fastening plate, the heat sink 11, and the electrode structure 25 may be fastened to the base plate using the screw 55 from the side of the fastening plate. Specifically, a flat fastening plate (not shown) having a through hole is further placed on the heat sink 11, and the screw 55 is inserted through the through hole of the fastening plate, the through hole 115 of the heat sink 11, the through hole 125 of the anode electrode 12, the through hole 135 of the insulating sheet 13, and the through hole 145 of the cathode electrode 14, and screwed into the tap of the base plate for fastening. Thereby, the heat sink 11 and the anode electrode 12 can be pushed in parallel and uniformly. As a result, even if there is a partial unevenness in the thickness of the applied conductive adhesive 202, the heat sink 11 and the anode electrode 12 are joined so as to be parallel. The fastening plate is preferably a flat plate larger in size than the heat sink 11 in order to uniformly press the heat sink 11 during fastening with the screw 55. After the joining is completed, the screw 55 is removed, and when the fastening plate is used, the fastening plate is also removed. As described above, the laser emission unit 20 is obtained.

[0079] Thereafter, the FAC31 is fixed to the laser emission unit 20 with an adhesive 35 or the like. The laser emission unit 20 to which the FAC31 is fixed is placed on the upper surface of the manifold 33. Screws, which are an example of fastening members, are inserted through the through holes 115, 125, 135, and 145 provided in each member of the laser emission unit 20, and are screwed into screw holes (not shown) provided in the manifold 33 for fastening. Thereby, the laser emission unit 20 is fixed to the manifold 33. Then, the SAC32 is fixed to the end of the manifold 33 in the emission direction of the laser beam L with an adhesive 36 or the like. Thereby, the semiconductor laser module 10 shown in FIGS. 1 to 3 is manufactured.

[0080] Note that, before temporarily fixing the cathode electrode 14 and the insulating sheet 13 in FIG. 11, the flatness and parallelism of the flat surface 142a of the convex portion 142 of the cathode electrode 14 and the flat surface 141a of the electrode facing portion 141, and the flatness and parallelism of the insulating sheet 13 may be measured, and members within a range where the flatness and parallelism are defined may be selected.

[0081] Specifically, before the first fastening step shown in FIG. 11, the parallelism between the flat surface 141a of the electrode facing portion 141 of the cathode electrode 14 and the flat surface 142a of the convex portion 142, and the parallelism between the lower surface 13a of the insulating sheet 13 that contacts the anode electrode 12 and the surface that contacts the cathode electrode 14 are measured. Thereafter, when the parallelism of the cathode electrode 14 and the parallelism of the insulating sheet 13 are within 0.03°, the measured anode electrode 12 and insulating sheet 13 may be used in the first fastening step. Such a step corresponds to the third parallelism measurement step.

[0082] Also, before the first fastening step shown in FIG. 11, measure the flatness of the cathode electrode 14, which is the flatness of the flat surface 141a of the electrode facing portion 141 of the cathode electrode 14 and the flatness of the flat surface 142a of the convex portion 142, and the flatness of the insulating sheet 13, which is the flatness of the surface in contact with the anode electrode 12 and the surface in contact with the cathode electrode 14. Then, when the flatness of the cathode electrode 14 and the flatness of the insulating sheet 13 are within 30 μm, the measured cathode electrode 14 and insulating sheet 13 may be used in the first fastening step. Such a process corresponds to the flatness measurement process.

[0083] Similarly, before temporarily fixing the cathode electrode 14 joined with the anode electrode 12 and the insulating sheet 13 in FIG. 16, measure the flatness and parallelism of the second portion 122 of the anode electrode 12, and select a member whose flatness and parallelism are within a defined range, specifically, a member whose flatness is within 30 μm and whose parallelism is within 0.03°.

[0084] By doing so, it is possible to suppress the variation in the gap 172 at each position between the laser diode element 16 and the cathode electrode 14 due to unevenness on the surface of the member. However, when measuring the parallelism and flatness of the first assembly 61 formed by assembling the cathode electrode 14 and the insulating sheet 13 in the first parallelism measurement step of FIG. 12, the third parallelism measurement step and the flatness measurement step may be omitted. Also, when measuring the parallelism and flatness of the second assembly 62 formed by assembling the cathode electrode 14 and the anode electrode 12 to which the insulating sheet 13 is joined in the second parallelism measurement step of FIG. 17, the step of measuring the flatness and parallelism of the second portion 122 of the anode electrode 12 and selecting a member whose flatness and parallelism are within a defined range, that is, a member whose flatness is within 30 μm and whose parallelism is within 0.03° may be omitted.

[0085] In the semiconductor laser module 10 according to Embodiment 1, the power supply structure 17 disposed between the laser diode element 16 and the cathode electrode 14 is constituted by a conductive ribbon 17a, and the insulating sheet 13 is constituted by one member. Further, on the surface of the cathode electrode 14 and the insulating sheet 13 joined to the cathode electrode 14 facing the anode electrode 12, the parallelism between the flat surface 142a of the convex portion 142 and the surface of the insulating sheet 13 on the anode electrode 12 side is set within 0.03°, and on the surface of the cathode electrode 14 and the anode electrode 12 joined to the cathode electrode 14 via the insulating sheet 13 facing the heat sink 11, the parallelism between the flat surface 142a of the convex portion 142 and the surface of the anode electrode 12 on the heat sink 11 side is set within 0.03°. As a result, variations at each position in the gap 172 between the laser diode element 16 and the cathode electrode 14 can be suppressed. By making the gap 172 uniform, the ridges of the conductive ribbon 17a between the laser diode element 16 and the flat surface 142a of the convex portion 142 of the cathode electrode 14 receive the same stress regardless of the position on the laser diode element 16. As a result, the amount of collapse of the ridges of the conductive ribbon 17a can be made uniform over the entire surface of the laser diode element 16. And the contact area of the conductive ribbon 17a with the laser diode element 16 corresponds to the amount of collapse of the ridges of the conductive ribbon 17a, and the amount of collapse can also be made uniform over the entire surface of the laser diode element 16. That is, it has the effect of suppressing variations in deformation due to the location of the conductive ribbon 17a, which is the power supply structure 17 between the cathode electrode 14 corresponding to the upper electrode block and the laser diode element 16, as compared with the conventional case.

[0086] The manufacturing method of the semiconductor laser module 10 includes a first parallelism measurement step, a first bonding step, a second parallelism measurement step, and a second bonding step. In the first parallelism measurement step, the parallelism of the first fastening body 61, in which the insulating sheet 13 is fastened to the electrode facing portion 141 of the cathode electrode 14 with a fastening member, between the flat surface 142a of the convex portion 142 and the lower surface 13a, which is the first surface on the side opposite to the surface of the insulating sheet 13 that contacts the cathode electrode 14, is measured. In the first bonding step, when the parallelism of the first fastening body 61 is within 0.03°, the insulating sheet 13 is bonded to the electrode facing portion 141 of the anode electrode 12 via the adhesive 201. In the second parallelism measurement step, the parallelism of the second fastening body 62, in which the anode electrode 12 is fastened to the electrode facing portion 141 of the cathode electrode 14 with a fastening member via the insulating sheet 13, between the flat surface 142a of the convex portion 142 and the second surface on the side opposite to the surface of the anode electrode 12 that contacts the insulating sheet 13, is measured. In the second bonding step, when the parallelism of the second fastening body 62 is within 0.03°, the anode electrode 12 is bonded to the electrode facing portion 141 of the cathode electrode 14 to which the insulating sheet 13 is bonded via an adhesive. As a result, in the subsequent electrode structure bonding step, when the heat sink 11 and the electrode structure 25 are bonded, variations at each position in the gap 172 between the laser diode element 16 and the cathode electrode 14 can be suppressed. As a result, over the entire surface of the laser diode element 16, the amount of collapse of the peaks of the conductive ribbon 17a becomes uniform, and the occurrence of current concentration due to variations in the contact area of the conductive ribbon 17a with the laser diode element 16 can be suppressed. That is, it has the effect of being able to manufacture the semiconductor laser module 10 in which variations in deformation due to the location of the power supply structure 17 between the cathode electrode 14 and the laser diode element 16 are suppressed as compared with the conventional case.

[0087] Further, the parallelism of the first fastening body 61 in which the cathode electrode 14 and the insulating sheet 13 are temporarily fixed with a fastening member was measured. When the parallelism of the first fastening body 61 is not within 0.03°, the combination of the cathode electrode 14 and the insulating sheet 13 was changed. In this way, since the first fastening body 61 is not joined with an adhesive, it can be easily disassembled into the respective members after measuring the parallelism. Therefore, it becomes possible to reuse either one of the cathode electrode 14 and the insulating sheet 13 that did not satisfy the conditions.

[0088] Similarly, the parallelism of the second fastening body 62 in which the cathode electrode 14 joined with the insulating sheet 13 and the anode electrode 12 are temporarily fixed with a fastening member was measured. When the parallelism of the second fastening body 62 is not within 0.03°, the combination of the cathode electrode 14 joined with the insulating sheet 13 and the anode electrode 12 was changed. In this way, since the second fastening body 62 is not joined with an adhesive, it can be easily disassembled into the respective members after measuring the parallelism. Therefore, it becomes possible to reuse either one of the cathode electrode 14 joined with the insulating sheet 13 and the anode electrode 12 that did not satisfy the conditions.

[0089] Furthermore, in the first joining step, a flat fastening plate provided with a through hole is placed on the insulating sheet 13, and the fastening plate, the insulating sheet 13, and the cathode electrode 14 are fastened to the base plate from the side of the fastening plate using a screw 55. In the second joining step, the fastening plate is placed on the anode electrode 12, and the fastening plate, the anode electrode 12, the insulating sheet 13, and the cathode electrode 14 are fastened to the base plate from the side of the fastening plate using a screw 55. Further, in the electrode structure joining step, the fastening plate is placed on the heat sink 11, and the fastening plate, the heat sink 11, and the electrode structure 25 are fastened to the base plate from the side of the fastening plate using a screw 55. As a result, since the flat fastening plate uniformly presses the entire joining target by fastening with the screw 55, it also has the effect of maintaining the parallelism of the surfaces between the two members of the joining target.

[0090] Embodiment 2. The semiconductor laser module 10 described in Embodiment 1 can be used as a light source of a laser processing apparatus. FIG. 23 is a diagram schematically showing an example of the configuration of a laser processing apparatus according to Embodiment 2. The laser processing apparatus 300 includes a laser oscillator 310, an optical fiber 320, and a processing head 330.

[0091] The laser oscillator 310 emits laser light. FIG. 24 is a diagram schematically showing an example of the configuration of a laser oscillator used in the laser processing apparatus according to Embodiment 2. The laser oscillator 310 includes a plurality of semiconductor laser modules 10, an optical coupling section 311, and an external resonance mirror 312. The semiconductor laser module 10 has the structure described in Embodiment 1. The optical coupling section 311 couples the laser light L from the plurality of semiconductor laser modules 10. As the optical coupling section 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 section 311 and reflects the remaining part toward 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.

[0092] Returning to FIG. 23, the optical fiber 320 transmits the combined laser light Lx emitted from the laser oscillator 310 to the processing head 330.

[0093] 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.

[0094] In the laser processing apparatus 300 according to the second embodiment, in the semiconductor laser module 10, the power supply structure 17 disposed between the laser diode element 16 and the cathode electrode 14 is constituted by a conductive ribbon 17a, and the insulating sheet 13 is constituted by one member. Further, on the surface of the cathode electrode 14 and the insulating sheet 13 joined to the cathode electrode 14 facing the anode electrode 12, the parallelism between the flat surface 142a of the convex portion 142 and the surface of the insulating sheet 13 on the anode electrode 12 side is set within 0.03°, and on the surface of the cathode electrode 14 and the anode electrode 12 joined to the cathode electrode 14 via the insulating sheet 13 facing the heat sink 11, the parallelism between the flat surface 142a of the convex portion 142 and the surface of the anode electrode 12 on the heat sink 11 side is set within 0.03°. As a result, variations at each position in the gap 172 between the laser diode element 16 and the cathode electrode 14 can be suppressed. By making the gap 172 uniform, the ridges of the conductive ribbon 17a between the laser diode element 16 and the flat surface 142a of the convex portion 142 of the cathode electrode 14 receive the same stress regardless of the position on the laser diode element 16. As a result, the amount of crushing of the ridges of the conductive ribbon 17a can be made uniform over the entire surface of the laser diode element 16. And the contact area of the conductive ribbon 17a with the laser diode element 16 corresponds to the amount of crushing of the ridges of the conductive ribbon 17a, and the amount of crushing can also be made uniform over the entire surface of the laser diode element 16. That is, there is an effect that a laser processing apparatus 300 having a semiconductor laser module 10 in which variations in deformation due to the location of the conductive ribbon 17a, which is the power supply structure 17 between the cathode electrode 14 corresponding to the upper electrode block and the laser diode element 16, are suppressed compared to the conventional case can be obtained.

[0095] The configurations shown in the above embodiments are examples, and it is possible to combine them with other known techniques, to combine the embodiments with each other, and to omit or change a part of the configuration without departing from the gist.

[0096] Hereinafter, aspects of the present disclosure will be collectively described as appendices.

[0097] [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 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 power supply structure is constituted by a corrugated conductive ribbon disposed between the laser diode element and the second electrode. The insulating layer is constituted by one member. On the surface of the second electrode and the insulating layer joined to the second electrode facing the first electrode, the parallelism between the flat surface of the convex portion and the surface of the insulating layer on the first electrode side is within 0.03°. A semiconductor laser module, characterized in that on the surface of the second electrode and the first electrode joined to the second electrode via the insulating layer facing the heat sink, the parallelism between the flat surface of the convex portion and the surface of the first electrode on the heat sink side is within 0.03°. [Appendix 2] The second electrode has a parallelism within 0.03° between the flat surface of the electrode facing portion and the flat surface of the convex portion. The semiconductor laser module according to Supplementary Note 1, wherein the parallelism between the surface of the insulating layer in contact with the first electrode and the surface of the insulating layer in contact with the second electrode is within 0.03°. [Supplementary Note 3] The flat surface of the electrode facing portion of the second electrode and the flat surface of the convex portion have flatness within 30 μm. The semiconductor laser module according to Supplementary Note 1 or 2, wherein the flatness between the surface of the insulating layer in contact with the first electrode and the surface of the insulating layer in contact with the second electrode is within 30 μm. [Supplementary Note 4] The heat sink, the first electrode, the insulating layer, and the second electrode have through holes penetrating in the stacking direction of the semiconductor laser module. A manifold provided with a screw hole on the surface supporting the heat sink. A screw inserted through the through holes of the heat sink, the first electrode, the insulating layer, and the second electrode and screwed into the screw hole of the manifold. The semiconductor laser module according to any one of Supplementary Notes 1 to 3, further comprising the above. [Supplementary Note 5] A laser oscillator having a plurality of semiconductor laser modules according to any one of Supplementary Notes 1 to 4, 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 the above. [Supplementary Note 6] A first fastening step of forming a first fastening body by fastening an insulating layer to an electrode facing portion of a second electrode having an electrode facing portion with 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, with a fastening member. A first parallelism measurement step of measuring the parallelism of the first fastening member, which is the parallelism between the flat surface of the convex portion of the first fastening member and a first surface on the opposite side of the surface of the insulating layer that contacts the second electrode; A first bonding step of bonding the insulating layer to the electrode facing portion of the second electrode via an adhesive when the parallelism of the first fastening member is within 0.03°; A second fastening step of fastening the first electrode to the electrode facing portion of the second electrode via the insulating layer with a fastening member to form a second fastening member; A second parallelism measurement step of measuring the parallelism of the second fastening member, which is the parallelism between the flat surface of the convex portion of the second fastening member and a second surface on the opposite side of the surface of the first electrode that contacts the insulating layer; A second bonding step of bonding the first electrode to the electrode facing portion of the second electrode to which the insulating layer is bonded via an adhesive when the parallelism of the second fastening member is within 0.03°; A power supply structure bonding 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; An element bonding step of bonding a laser diode element that emits laser light onto a submount having conductivity and heat conductivity; A submount bonding step of bonding the submount to an element arrangement region of a heat sink; An electrode structure bonding step of applying a conductive adhesive to the first electrode and bonding the electrode structure and the heat sink such that the power supply structure and the laser diode element face each other and the electrode arrangement region, which is a region different from the element arrangement region of the heat sink, faces the first electrode; including In the power supply structure bonding step, a method for manufacturing a semiconductor laser module, characterized in that a conductive ribbon is bonded in a waveform as the power supply structure. [Appendix 7] Before the first fastening step, further including a third parallelism measurement step of measuring the parallelism between the flat surface of the electrode facing portion of the second electrode and the flat surface of the convex portion, and the parallelism between the surface of the insulating layer that contacts the first electrode and the surface of the insulating layer that contacts the second electrode; In the first fastening step, when the parallelism of the second electrode and the parallelism of the insulating layer are within 0.03°, the measured second electrode and the insulating layer are used, and the method for manufacturing a semiconductor laser module according to appended note 6 is characterized in that. [Appended note 8] Before the first fastening step, a flatness measurement step of measuring the flatness of the second electrode, which is the flatness of the flat surface of the electrode facing portion of the second electrode and the flat surface of the convex portion, and the flatness of the insulating layer, which is the flatness of the surface of the insulating layer in contact with the first electrode and the surface in contact with the second electrode, is further included. In the first fastening step, when the flatness of the second electrode and the flatness of the insulating layer are within 30 μm, the measured second electrode and the insulating layer are used, and the method for manufacturing a semiconductor laser module according to appended note 6 or 7 is characterized in that. [Appended note 9] The fastening member is a screw. In the first bonding step, the second electrode is placed on a base plate with a tapped hole, the insulating layer is placed on the electrode facing portion of the second electrode where the adhesive is applied, the screw is inserted through the through holes provided in the second electrode and the insulating layer, and the screw is screwed into the tap of the base plate and fastened and bonded. In the second bonding step, the second electrode is placed on the base plate, the first electrode is placed on the insulating layer where the adhesive is applied to the electrode facing portion of the second electrode, the screw is inserted through the through holes provided in the first electrode, the insulating layer, and the second electrode, and the screw is screwed into the tap of the base plate and fastened and bonded. In the electrode structure bonding step, the electrode structure is placed on the base plate, the heat sink is placed on the electrode structure where the conductive adhesive is applied to the first electrode, the screw is inserted through the through holes provided in the heat sink and the electrode structure, and the screw is screwed into the tap of the base plate and fastened, and the method for manufacturing a semiconductor laser module according to any one of appended notes 6 to 8 is characterized in that. [Appended note 10] In the first joining step, a flat fastening plate provided with a through hole is placed on the insulating layer, and the fastening plate, the insulating layer, and the second electrode are fastened to the base plate from the side of the fastening plate using the screw. In the second joining step, the fastening plate is placed on the first electrode, and the fastening plate, the first electrode, the insulating layer, and the second electrode are fastened to the base plate from the side of the fastening plate using the screw. In the electrode structure joining step, the fastening plate is placed on the heat sink, and the fastening plate, the heat sink, and the electrode structure are fastened to the base plate from the side of the fastening plate using the screw. The manufacturing method of the semiconductor laser module according to appended note 9, characterized in that. [Appended note 11] In the first parallelism measurement step, when the parallelism of the first fastening body is not within 0.03°, one of the second electrode and the insulating layer is replaced with another member, and the process returns to the first joining step. The manufacturing method of the semiconductor laser module according to any one of appended notes 6 to 10, characterized in that. [Appended note 12] In the second parallelism measurement step, when the parallelism of the second fastening body is not within 0.03°, the first electrode is replaced with another member, and the process returns to the second joining step. The manufacturing method of the semiconductor laser module according to any one of appended notes 6 to 10, characterized in that.

Explanation of reference numerals

[0098] 10 Semiconductor laser module, 11 Heat sink, 12 Anode electrode, 13 Insulating sheet, 13a, 122a Lower surface, 14 Cathode electrode, 15 Submount, 16 Laser diode element, 17 Power supply structure, 17a Conductive ribbon, 20 Laser emission section, 25 Electrode structure, 31 FAC, 32 SAC, 33 Manifold, 35, 36, 201 Adhesive, 61 First fastening body, 62 Second fastening body, 115, 125, 135, 145 Through hole, 121 First part, 122 Second part, 141 Electrode facing portion, 141a, 142a Flat surface, 142 Convex portion, 171 Top, 172 Gap, 173 Bonding portion, 202 Conductive adhesive, 300 Laser processing apparatus, 310 Laser oscillator, 311 Optical coupling section, 312 External resonance mirror, 320 Optical fiber, 330 Processing head, 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 power supply structure is constituted by a corrugated conductive ribbon disposed between the laser diode element and the second electrode, the insulating layer is constituted by one member, in a plane facing the first electrode of the second electrode and the insulating layer joined to the second electrode, the parallelism between the flat surface of the convex portion and the surface of the insulating layer on the first electrode side is within 0.03°, A semiconductor laser module, wherein in a plane facing the heat sink of the second electrode and the first electrode joined to the second electrode via the insulating layer, the parallelism between the flat surface of the convex portion and the surface of the first electrode on the heat sink side is within 0.03°.

2. the second electrode has a parallelism within 0.03° between the flat surface of the electrode facing portion and the flat surface of the convex portion, The semiconductor laser module according to claim 1, wherein the insulating layer has a parallelism within 0.03° between a surface in contact with the first electrode and a surface in contact with the second electrode.

3. the flat surface of the electrode facing portion of the second electrode and the flat surface of the convex portion have a flatness within 30 μm, The semiconductor laser module according to claim 1, wherein the surface of the insulating layer in contact with the first electrode and the surface in contact with the second electrode have a flatness within 30 μm.

4. the heat sink, the first electrode, the insulating layer, and the second electrode have a through hole penetrating in the stacking direction of the semiconductor laser module, a manifold having a screw hole provided on a surface supporting the heat sink, A screw that is inserted through the through holes of the heat sink, the first electrode, the insulating layer, and the second electrode and is screwed into the threaded hole of the manifold, The semiconductor laser module according to claim 1, further comprising

5. A laser oscillator having a plurality of the semiconductor laser modules according to any one of claims 1 to 4, 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 comprising

6. A first fastening step of fastening an insulating layer to an electrode facing portion of a 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, to form a first fastening body, A first parallelism measurement step of measuring the parallelism of the first fastening body, which is the parallelism between the flat surface of the convex portion of the first fastening body and a first surface on the opposite side of the surface of the insulating layer that contacts the second electrode, A first bonding step of bonding the insulating layer to the electrode facing portion of the second electrode via an adhesive when the parallelism of the first fastening body is within 0.03°, A second fastening step of fastening the first electrode to the electrode facing portion of the second electrode via the insulating layer with a fastening member to form a second fastening body, A second parallelism measurement step of measuring the parallelism of the second fastening body, which is the parallelism between the flat surface of the convex portion of the second fastening body and a second surface on the opposite side of the surface of the first electrode that contacts the insulating layer, A second bonding step of bonding the first electrode to the electrode facing portion of the second electrode to which the insulating layer is bonded via an adhesive when the parallelism of the second fastening body is within 0.03°, A power supply structure body bonding step of bonding a power supply structure body having conductivity, heat conductivity, and elasticity to the convex portion of the second electrode to form an electrode structure body, An element bonding step of bonding a laser diode element that emits laser light onto a submount having conductivity and heat conductivity, A submount bonding step of bonding the submount to an element arrangement region of a heat sink Apply a conductive adhesive to the first electrode, and join the electrode structure and the heat sink so that the power supply structure and the laser diode element face each other, and an electrode arrangement region, which is a region different from the element arrangement region of the heat sink, faces the first electrode. This is an electrode structure joining step. including In the power supply structure joining step, a method for manufacturing a semiconductor laser module is characterized in that a conductive ribbon is joined in a waveform as the power supply structure.

7. Before the first fastening step, further include a third parallelism measurement step of measuring the parallelism between the flat surface of the electrode facing portion of the second electrode and the flat surface of the convex portion, and the parallelism between the surface of the insulating layer in contact with the first electrode and the surface in contact with the second electrode. In the first fastening step, when the parallelism of the second electrode and the parallelism of the insulating layer are within 0.03°, the measured second electrode and insulating layer are used. This is the method for manufacturing a semiconductor laser module according to claim 6.

8. Before the first fastening step, further include a flatness measurement step of measuring the flatness of the second electrode, which is the flatness of the flat surface of the electrode facing portion of the second electrode and the flat surface of the convex portion, and the flatness of the insulating layer, which is the flatness of the surface of the insulating layer in contact with the first electrode and the surface in contact with the second electrode. In the first fastening step, when the flatness of the second electrode and the flatness of the insulating layer are within 30 μm, the measured second electrode and insulating layer are used. This is the method for manufacturing a semiconductor laser module according to claim 6.

9. The fastening member is a screw. In the first joining step, place the second electrode on a base plate with a tapped hole, place the insulating layer on the electrode facing portion of the second electrode where the adhesive is applied, insert the screw through the through holes provided in the second electrode and the insulating layer, and thread it into the tap of the base plate to fasten and join. In the second joining step, place the second electrode on the base plate, place the first electrode on the insulating layer where the adhesive is applied to the electrode facing portion of the second electrode, insert the screw through the through holes provided in the first electrode, the insulating layer, and the second electrode, and thread it into the tap of the base plate to fasten and join. In the electrode structure bonding step, the electrode structure is placed on the base plate, the heat sink is placed on the electrode structure coated with the conductive adhesive on the first electrode, the screw is inserted through the through holes provided in the heat sink and the electrode structure, and the semiconductor laser module manufacturing method according to claim 6, characterized in that it is screwed and fastened to the tap of the base plate.

10. In the first bonding step, a flat fastening plate provided with a through hole is placed on the insulating layer, and the fastening plate, the insulating layer, and the second electrode are fastened to the base plate from the side of the fastening plate using the screw. In the second bonding step, the fastening plate is placed on the first electrode, and the fastening plate, the first electrode, the insulating layer, and the second electrode are fastened to the base plate from the side of the fastening plate using the screw. In the electrode structure bonding step, the fastening plate is placed on the heat sink, and the fastening plate, the heat sink, and the electrode structure are fastened to the base plate from the side of the fastening plate using the screw, which is the semiconductor laser module manufacturing method according to claim 9.

11. In the first parallelism measurement step, when the parallelism of the first fastening body is not within 0.03°, one of the second electrode and the insulating layer is replaced with another member, and the process returns to the first fastening step, which is the semiconductor laser module manufacturing method according to any one of claims 6 to 10.

12. In the second parallelism measurement step, when the parallelism of the second fastening body is not within 0.03°, the first electrode is replaced with another member, and the process returns to the second fastening step, which is the semiconductor laser module manufacturing method according to any one of claims 6 to 10.

Images