A pre-soldering structure for a heat sink, a manufacturing method thereof, and a semiconductor laser

Abstract

The present application relates to a pre-set solder structure for a heat sink, a manufacturing method and a semiconductor laser. The method for manufacturing a pre-set solder structure for a heat sink includes providing a heat sink, the heat sink having a groove, sputtering a metal layer in the groove, the sputtering conditions being: vacuum degree 0.8-5 Pa, sputtering rate: 15-25 A / s, substrate temperature: 100-200°C, the metal layers sequentially comprising a titanium layer, a platinum layer, and a gold layer, wherein the sputtering thicknesses of the metal layers are: titanium layer 1.5 μm, platinum layer 2.0 μm, and gold transition layer 0.5 μm; electroplating a first gold layer, a tin layer, and a second gold layer on the sputtered metal layers in sequence to obtain a solder layer, wherein the conditions for electroplating the first gold layer are: plating solution temperature 50-65°C, plating rate 1500 A / min, and plating thickness: 2.8 μm; the conditions for electroplating the tin layer are: plating solution temperature room temperature, plating rate 3000 A / min, and plating thickness: 2.6 μm; and the conditions for electroplating the second gold layer are: plating solution temperature room temperature, plating rate 3000 A / min, and plating thickness: 2.5 um, and the second gold layer does not protrude from the groove; and the electroplated solder layer is annealed, the annealing conditions are: 200°, 150S in the first stage, 300°, 50S in the second stage.

Description

Technical Field

[0001] The present application relates to the technical field of semiconductor laser chip packaging, and in particular to a pre-set solder structure for a heat sink, a manufacturing method, and a semiconductor laser. Background Art

[0002] Gold-tin solder is a commonly used packaging welding material. With the popularization of automated assembly and the strict requirements of laser flip-chip packaging on solder thickness, the thickness of gold-tin solder sheets is used for laser flip-chip welding at a minimum of 15um. However, this thickness will cause solder overflow to form balls at the end, blocking the laser light output end and affecting the light output efficiency. Summary of the Invention

[0003] The present application provides a pre-set solder structure for a heat sink, which can solve the problem of solder balls formed by overflow.

[0004] A method for manufacturing a pre-set solder structure for a heat sink, comprising the following steps:

[0005] A heat sink is provided, wherein the heat sink has a groove, and a metal layer is sputtered in the groove. The sputtering conditions are: vacuum degree 0.8-5 Pa, sputtering rate: 15-25 A / s, substrate temperature: 100-200°C, the metal layer sequentially comprising a titanium layer, a platinum layer, and a gold layer, wherein the sputtering thicknesses of the metal layers are: titanium layer 1.5 μm, platinum layer 2.0 μm, and gold transition layer 0.5 μm;

[0006] Electroplating a solder layer on the sputtered metal layer, the solder layer sequentially comprising a first gold layer, a tin layer, and a second gold layer, wherein the conditions for electroplating the first gold layer are: a plating bath temperature of 50-65° C., a plating rate of 1500 A / min, and a plating thickness of 2.8 μm; the conditions for electroplating the tin layer are: a plating bath temperature of room temperature, a plating rate of 3000 A / min, and a plating thickness of 2.6 μm; and the conditions for electroplating the second gold layer are: a plating bath temperature of room temperature, a plating rate of 3000 A / min, and a plating thickness of 2.5 μm, and the second gold layer does not protrude from the groove; and

[0007] The electroplated solder layer is annealed under the following conditions: 200°, 150S in the first stage and 240°, 50S in the second stage.

[0008] By adopting the above solution, the metal layer and the solder layer are formed in the groove. The metal layer serves as a transition layer between the solder layer and the heat sink. The thickness of the metal layer and the solder layer is precisely controlled, so that the thickness of the gold-tin solder sheet is reduced to less than 8um, avoiding the balling phenomenon caused by an excessively thick solder layer and reducing the possibility of solder overflow during the subsequent pre-set solder welding process; moreover, the balling phenomenon is further solved; by dividing the annealing conditions into two stages, the lower temperature (200°C) in the first stage helps to gradually relieve the stress inside the material, and the higher temperature (240°C) in the second stage can promote grain growth and phase transformation, which helps to improve the mechanical properties and microstructure of the material.

[0009] In one embodiment, the opening of the groove gradually increases from the bottom to the top.

[0010] The above solution helps to reduce the formation of voids in the solder layer due to shrinkage of the solder during annealing.

[0011] In one embodiment, the groove includes a plurality of sub-grooves, and the opening of each sub-groove increases from bottom to top to form a stepped shape. One of the metal layers is formed in each sub-groove, and the projection of the upper metal layer on the bottom surface of the heat sink completely covers the projection of the lower metal layer on the bottom surface of the heat sink.

[0012] By adopting the above solution, the opening of each sub-slot gradually increases, which can reduce the stress concentration between layers. Different metal layers may have different thermal expansion coefficients. The stepped design can provide appropriate expansion space for each layer of metal, reducing the internal stress caused by thermal expansion mismatch.

[0013] In one embodiment, after the annealing step, the method further includes fixing a self-healing solder on the surface of the solder layer, wherein the self-healing solder is configured to self-repair the solder layer when a crack occurs in the solder layer.

[0014] By providing a self-healing solder on the surface of the solder layer, the self-healing solder is configured to self-repair the solder layer when cracks occur in the solder layer.

[0015] In one embodiment, the self-healing solder includes at least microcapsule particles, the microcapsule particles include a wall material layer and a self-healing material filled in the wall material layer, the wall material layer is a stress-sensitive material or a light-sensitive material, and the self-healing material includes at least liquid metal.

[0016] In one embodiment, the self-healing solder is a composite network structure layer formed by SMA fibers and microcapsule particles.

[0017] A pre-set solder structure for a heat sink, comprising:

[0018] A heat sink, wherein the heat sink is provided with a groove;

[0019] A metal layer is formed in the groove, the metal layer sequentially comprising a titanium layer, a platinum layer, and a gold layer, wherein the sputtering thicknesses of the metal layers are: 1.5 μm for the titanium layer, 2.0 μm for the platinum layer, and 0.5 μm for the gold transition layer; and

[0020] The solder layer includes a first gold layer, a tin layer and a second gold layer in sequence, the first gold layer has a thickness of 2.8 μm, the tin layer has a thickness of 2.6 μm, and the second gold layer has a thickness of 2.5 μm, and the second gold layer does not protrude from the groove.

[0021] In one embodiment, a self-healing solder is fixed on the surface of the solder layer, and the self-healing solder is configured to self-repair the solder layer when a crack occurs in the solder layer.

[0022] In one embodiment, the self-healing solder includes at least microcapsule particles, the microcapsule particles include a wall material layer and a self-healing material filled in the wall material layer, the wall material layer is any one of heat-sensitive, light-sensitive or stress-sensitive materials, and the self-healing material includes at least liquid metal.

[0023] A semiconductor laser comprises the above-mentioned pre-set solder structure for a heat sink and a laser chip, wherein the laser chip is fixed on the solder layer by reflow soldering.

[0024] In summary, this application includes at least one of the following beneficial technical effects:

[0025] 1. By adopting the above solution, the solder layer is formed in the groove and the thickness of the metal layer and solder layer is precisely controlled, avoiding the balling phenomenon caused by an excessively thick solder layer and reducing the possibility of solder overflow during the subsequent pre-set soldering process. In addition, the balling phenomenon is further resolved. The annealing conditions are divided into two stages. The lower temperature (200°C) in the first stage helps to gradually relieve the stress within the material, and the higher temperature (240°C) in the second stage can promote grain growth and phase transformation, which helps to improve the mechanical properties and microstructure of the material.

[0026] 2. By adopting the above solution, the opening of each sub-slot gradually increases, which can reduce stress concentration between layers. Different metal layers may have different thermal expansion coefficients. The stepped design can provide appropriate expansion space for each metal layer, reducing the internal stress caused by thermal expansion mismatch.

[0027] 3. By providing a self-healing solder on the surface of the solder layer, the self-healing solder is configured to self-repair the solder layer when cracks occur in the solder layer, thereby enhancing the conductive performance of the solder layer that is subsequently affected by cracks. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a structural diagram of a pre-set solder structure for a heat sink provided in the first embodiment of the present application;

[0029] Figure 2 This is a structural diagram of a pre-set solder structure for a heat sink provided in the second embodiment of the present application;

[0030] Figure 3 This is a structural diagram of a pre-set solder structure for a heat sink provided in the third embodiment of the present application.

[0031] Explanation of the accompanying symbols: 1. Heat sink; 2. Metal layer; 101. Groove; 21. Titanium layer; 22. Platinum layer; 23. Gold transition layer; 31. First gold layer; 32. Tin layer; 33. Second gold layer; 3. Solder layer; 11. Base heat sink; 12. Transition heat sink; 102. Sub-groove; 103. Sub-groove; 4. Self-healing solder. DETAILED DESCRIPTION

[0032] Therefore, it is necessary to provide a manufacturing method for forming a pre-installed solder structure in the structure of the heat sink 1 and a pre-installed solder structure for the heat sink 1 .

[0033] The following is combined with Figure 1-3 The manufacturing method of the pre-installed solder structure for the heat sink 1 and the pre-installed solder structure for the heat sink 1 provided in the present application are further described in detail.

[0034] See also Figure 1 A method for manufacturing a pre-set solder structure for a heat sink comprises the following steps:

[0035] S1: providing a heat sink 1 , forming a groove 101 on the surface of the heat sink 1 , and sputtering a metal layer 2 in the groove 101 .

[0036] The sputtering conditions are: vacuum degree 0.8-5 Pa, sputtering rate: 15-25 A / s, substrate temperature: 100-200°C, the metal layer 2 includes a titanium layer 21, a platinum layer 22, and a gold transition layer 23 in sequence, wherein the sputtering thicknesses of the metal layer 2 are: the titanium layer 21 is 1.5 um, the platinum layer 22 is 2.0 um, and the gold transition layer 23 is 0.5 um.

[0037] In a feasible embodiment, the opening of the groove 101 gradually increases from the bottom to the top.

[0038] In a further embodiment, the groove 101 includes a plurality of sub-grooves 102, the opening of each sub-groove 102 increases from bottom to top to form a stepped shape, and one layer of the metal layer 2 is formed in each sub-groove 102, and the projection of the upper metal layer 2 on the bottom surface of the heat sink 1 completely covers the projection of the lower metal layer 2 on the bottom surface of the heat sink 1.

[0039] S2: Electroplating a solder layer 3 on the sputtered metal layer 2. The solder layer 3 sequentially includes a first gold layer 31, a tin layer 32, and a second gold layer 33. The conditions for electroplating the first gold layer 31 are: a bath temperature of 50-65°C, a plating rate of 1500A / min, and a plating thickness of 2.8μm; the conditions for electroplating the tin layer 32 are: a bath temperature of room temperature, a plating rate of 3000A / min, and a plating thickness of 2.6μm; and the conditions for electroplating the second gold layer 33 are: a bath temperature of room temperature, a plating rate of 3000A / min, and a plating thickness of 2.5μm. The second gold layer 33 does not protrude from the groove 101. This design consideration is to prevent the subsequent self-healing solder 4 from releasing liquid metal overflow during repair, causing a short circuit between adjacent pads.

[0040] In this embodiment, the solder layer 3 is formed in the groove 101, and the thickness of the metal layer 2 and the solder layer 3 is precisely controlled to avoid the balling phenomenon caused by an excessively thick solder layer 3; the metal layer 2 is plated first, and then the solder layer 3 is plated. The metal layer 2 serves as a bridge of adhesion between the solder layer 3 and the substrate, mainly to enable the solder layer 3 to adhere better to the surface of the metal layer 2; the electroplated layer can be used to repair minor defects that may exist in the sputtered layer and provide a more uniform surface.

[0041] More specifically, such a layer structure has the following technical effects: enhanced adhesion: the bottom titanium layer 21 can provide better adhesion, ensuring a stronger bond between the solder layer 3 and the heat sink 1 substrate.

[0042] Improve heat conduction efficiency: The titanium layer 21 has high thermal conductivity and can quickly conduct heat from the chip to the solder layer 3, and then from the solder layer 3 to the heat sink 1.

[0043] Preventing electrochemical corrosion: The titanium layer 21 and the platinum layer 22 serve as barrier layers to prevent electrochemical corrosion between the solder layer 3 and the heat sink 1 material.

[0044] Improve wettability: The gold transition layer, as the top layer of the metal layer 2 , can improve the wettability of the solder on the surface of the heat sink 1 and ensure good contact between the solder layer 3 and the metal layer 2 .

[0045] Improving the mechanical strength of the solder layer 3: The metal layer 2 can enhance the mechanical strength of the solder layer 3 and improve the durability and reliability of the overall structure.

[0046] A tin layer 32 is provided between the first gold layer 31 and the second gold layer 33. Tin optimizes the physical properties of the solder joint, such as plasticity and toughness, making it more adaptable to various operating environments. Tin layer 32 has a relatively low melting point. When alloyed with other metals, this further lowers the melting point, allowing the soldering process to proceed at lower temperatures and reducing the risk of thermal damage. The second gold layer 33 provides antioxidant protection, preventing oxidation of the solder during high temperatures or prolonged use.

[0047] By designing the multi-layer metal layer 2 , the complementary advantages between different metal layers 2 can be achieved, so as to improve the thermal conductivity of the metal layer 2 and the solder layer 3 and enhance the corrosion resistance.

[0048] S3: Annealing the electroplated solder layer 3. Annealing conditions are: 200°, 150s in the first stage, and 240°, 50s in the second stage.

[0049] In this embodiment, the annealing conditions are divided into two stages. The lower temperature (200°C) in the first stage helps to gradually relieve the stress inside the material without immediately causing significant structural changes, which helps to prevent thermal shock or cracks caused by rapid temperature changes. Maintaining the temperature at a lower temperature for a period of time (150 seconds) allows the microstress in the material to be gradually released, reducing the residual stress of the material. The higher temperature (240°C) in the second stage can promote grain growth and phase transformation, which helps to improve the mechanical properties and microstructure of the material. The shorter high-temperature holding time (50 seconds) can prevent excessive grain growth and keep the microstructure of the material refined, thereby improving the strength and toughness of the material. By controlling the time of the high-temperature stage, the exposure time of the material to high temperature can be reduced, thereby reducing oxidation and possible performance degradation.

[0050] S4: Fixing a self-healing solder 4 on the surface of the solder layer 3, wherein the self-healing solder 4 is configured to self-repair the solder layer 3 when cracks occur in the solder layer 3. The surface of the self-healing solder 4 does not exceed the groove 101 or is just flush with the top surface of the groove 101.

[0051] In one feasible embodiment, the self-healing solder 4 comprises at least microcapsule particles, each comprising a wall material layer and a self-healing material filled within the wall material layer. The wall material layer is a stress-sensitive material, and the self-healing material comprises at least liquid metal. The liquid metal flows to and fills the crack due to capillary action, surface tension, or applied external forces (such as temperature and pressure). The repair material filled into the crack solidifies or dries under specific conditions (such as temperature, time, and chemical reaction), forming a solid state. The solidified repair material restores the conductivity and mechanical strength of the solder joint, completing the self-healing process and thereby restoring the conductivity of the solder layer 3.

[0052] In a feasible embodiment, the particle size of the microcapsule particles is between 0.1 μm and 200 μm. Preferably, the particle size of the microcapsule particles is 5 μm.

[0053] In one feasible embodiment, the wall material layer is polydimethylsiloxane (PDMS) or photosensitive polyacrylic acid (PSA) with a photosensitizer added. The wall material layer undergoes photolysis under light, allowing the self-healing material to flow to the crack under the action of surface tension to repair the crack.

[0054] In a feasible embodiment, the wall material layer is polyacrylic acid (PAA), which undergoes plastic deformation when subjected to stress, thereby triggering the rupture of the microcapsules.

[0055] In a feasible embodiment, a gallium-based alloy (EGaIn, where E represents gallium, Ga represents indium, and In represents tin) is used. This alloy is liquid at room temperature and has excellent fluidity and filling properties.

[0056] In a feasible embodiment, alloy powder, such as copper (Cu), nickel (Ni) or silver (Ag) powder, is further dispersed in the liquid metal. The alloy powder is used to enhance the mechanical properties and electrical conductivity of the composite material.

[0057] In a further embodiment, the self-healing solder 4 is a composite network structure layer formed by SMA fibers and microcapsule particles.

[0058] The shape memory alloy (SMA) fiber layer and the microcapsules containing liquid metal are combined to form a reinforced composite network structure layer, which can be achieved through the following steps and technologies:

[0059] S41: Designing microcapsules:

[0060] First, microcapsules are designed and manufactured. The wall materials of these microcapsules must have good chemical stability and mechanical strength, and be able to break under specific conditions to release the liquid metal inside.

[0061] S42: Microcapsules filled with liquid metal:

[0062] Liquid metal (such as gallium-based alloy, indium-based alloy, etc.) is filled into the microcapsule. This step requires ensuring the sealing of the microcapsule to prevent the liquid metal from leaking.

[0063] S43: Preparation of SMA fibers: S4: Production of SMA fibers. Commonly used SMA fibers are made of nickel-titanium alloy and have shape memory effect and superelasticity.

[0064] S44: Mixture of fiber and microcapsules:

[0065] The SMA fibers are mixed with the microcapsules and evenly dispersed in a matrix material, which can be a resin, plastic, or other type of pad material.

[0066] S45: Composite Molding

[0067] The SMA fibers and microcapsules are combined with a matrix material using appropriate molding techniques (such as thermoforming, injection molding, or lamination) to form a composite material.

[0068] Combining SMA fibers with the pad material creates a reinforced composite material. The SMA fibers not only enhance the mechanical properties of the pad but also facilitate repair through the shape memory effect when the solder is damaged.

[0069] See also Figure 1 The present application also provides a pre-set solder structure for a heat sink 1, comprising: a heat sink 1, a metal layer 2, a solder layer 3 and a self-healing solder 4.

[0070] The heat sink 1 is provided with a groove 101 . In a feasible embodiment, the opening of the groove 101 gradually increases from the bottom to the top.

[0071] In a further embodiment, the groove 101 includes a plurality of sub-grooves 102, the opening of each sub-groove 102 increases from bottom to top to form a stepped shape, and one layer of the metal layer 2 is formed in each sub-groove 102, and the projection of the upper metal layer 2 on the bottom surface of the heat sink 1 completely covers the projection of the lower metal layer 2 on the bottom surface of the heat sink 1.

[0072] A metal layer 2 is formed in the groove 101 , and the metal layer 2 includes a titanium layer 21 , a platinum layer 22 , and a gold transition layer 23 in sequence. The sputtering thicknesses of the metal layer 2 are: 1.5 μm for the titanium layer 21 , 2.0 μm for the platinum layer 22 , and 0.5 μm for the gold transition layer.

[0073] The solder layer 3 includes a first gold layer 31 , a tin layer 32 and a second gold layer 33 in sequence. The thickness of the first gold layer 31 is 2.8 μm, the thickness of the tin layer 32 is 2.6 μm, and the thickness of the second gold layer 33 is 2.5 μm. The second gold layer 33 does not protrude from the groove 101 .

[0074] The self-healing solder 4 is fixed to the surface of the solder layer 3 , and the self-healing solder 4 is configured to self-repair the solder layer 3 when a crack occurs in the solder layer 3 .

[0075] The self-healing solder 4 at least includes microcapsule particles, and the microcapsule particles include a wall material layer and a self-healing material filled in the wall material layer. The wall material layer is a heat-sensitive material, and the self-healing material at least includes liquid metal.

[0076] The present application also provides a semiconductor laser, comprising the pre-set solder structure for the heat sink 1 as described above and a laser chip, wherein the laser chip is fixed on the solder layer 3 by reflow soldering.

[0077] Example 2

[0078] See also Figure 2 Embodiment 2 is substantially the same as Embodiment 1, except that the heat sink 1 includes a base heat sink 11 and a transition heat sink 12 located on the surface of the base heat sink 11. The transition heat sink 12 has a greater thermal conductivity than the base heat sink 11, and the groove 101 is formed in the transition heat sink 12. For example, in one possible embodiment, the base heat sink 11 is made of metal, and the transition heat sink 12 is made of graphene.

[0079] Example 3

[0080] See also Figure 3 , Example 3 is basically the same as Example 1, except that the side wall of the groove 101 is further provided with a sub-groove 103 surrounding the side wall of the groove 101, and the sub-groove 103 can be connected with the groove 101, and the self-healing solder 4 is arranged in the sub-groove 103, and the wall material layer of the self-healing solder 4 can be arranged in a ring shape, and the self-healing solder 4 is embedded in the sub-groove 103.

[0081] In a further embodiment, the wall material of the microcapsules included in the self-healing solder 4 can be a heat-sensitive material, which can prevent or reduce the direct impact of the rising temperature during reflow on the self-healing material. In a more likely implementation, the wall material layer is more sensitive to temperature than the required reflow temperature, thus preventing the wall material layer from directly rupturing during reflow.

[0082] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A method for manufacturing a pre-set solder structure for a heat sink, characterized in that: The following steps are involved: A heat sink (1) is provided, wherein the heat sink (1) is provided with a groove (101), wherein the opening of the groove (101) gradually increases from the bottom to the top, wherein the groove (101) includes a plurality of sub-grooves (102), wherein the opening of each sub-groove (102) increases from the bottom to the top in sequence to form a step-like shape, wherein a metal layer (2) is sputtered in the groove (101), wherein the sputtering conditions are: vacuum degree 0.8-5 Pa, sputtering rate: 15-25 A / s, substrate temperature: 100-200° C., wherein the metal layer (2) sequentially includes a titanium layer (21), a platinum layer (22), and a gold transition layer (23), wherein one layer of the metal layer (2) is formed in each sub-groove (102), wherein the projection of the upper metal layer (2) on the bottom surface of the heat sink (1) completely covers the projection of the lower metal layer (2) on the bottom surface of the heat sink (1), wherein the sputtering thickness of the metal layer (2) is: the titanium layer (21) is 1.5 um, platinum layer (22) is 2.0 um, gold transition layer (23) is 0.5 um; electroplating a solder layer (3) on the sputtered metal layer (2), the solder layer (3) sequentially comprising a first gold layer (31), a tin layer (32) and a second gold layer (33), forming one layer of the solder layer (3) in each sub-slot (102), the projection of the upper solder layer (3) on the bottom surface of the heat sink (1) completely covering the projection of the lower solder layer (3) on the bottom surface of the heat sink (1), wherein the conditions for electroplating the first gold layer (31) are: plating solution temperature 50-65°C, plating rate 1500A / min, plating thickness: 2.8um; the conditions for electroplating the tin layer (32) are: plating solution temperature room temperature, plating rate 3000A / min, plating thickness: 2.6um; and the conditions for electroplating the second gold layer (33) are: plating solution temperature room temperature, plating rate 3000A / min, plating thickness: 2.5 um, and the second gold layer (33) does not protrude from the groove (101); and the electroplated solder layer (3) is annealed, and the annealing conditions are: 200°, 150S in the first stage, and 240°, 50S in the second stage.

2. The method for manufacturing a pre-deposited solder structure for a heat sink according to claim 1, characterized in that: After the annealing step, the method further includes fixing a self-healing solder (4) on the surface of the solder layer (3) or the side wall of the groove (101), wherein the self-healing solder (4) is configured to self-repair the solder layer (3) when cracks occur in the solder layer (3).

3. The method for manufacturing a pre-deposited solder structure for a heat sink according to claim 2, characterized in that: The self-healing solder (4) comprises at least microcapsule particles, the microcapsule particles comprising a wall material layer and a self-healing material filled in the wall material layer, the wall material layer being any one of heat-sensitive, light-sensitive or stress-sensitive materials, and the self-healing material comprising at least liquid metal.

4. The method for manufacturing a pre-deposited solder structure for a heat sink according to claim 3, wherein: The self-healing solder (4) is a composite network structure layer formed by SMA fibers and microcapsule particles.

5. A pre-set solder structure for a heat sink, characterized in that: include: A heat sink (1), wherein the heat sink (1) is provided with a groove (101), the opening of the groove (101) gradually increases from the bottom to the top, the groove (101) includes a plurality of sub-grooves (102), the opening of each sub-groove (102) increases from the bottom to the top in sequence to form a step-like shape; a metal layer (2), formed in the groove (101), the metal layer (2) sequentially including a titanium layer (21), a platinum layer (22), and a gold transition layer (23), one layer of the metal layer (2) is formed in each sub-groove (102), the projection of the upper metal layer (2) on the bottom surface of the heat sink (1) completely covers the projection of the lower metal layer (2) on the bottom surface of the heat sink (1), wherein the sputtering thickness of the metal layer (2) is respectively: 1.5 μm for the titanium layer (21), 2.0 μm for the platinum layer (22), and 0.5 μm for the gold transition layer (23). um; and a solder layer (3), the solder layer (3) sequentially comprising a first gold layer (31), a tin layer (32) and a second gold layer (33), one layer of the solder layer (3) being formed in each sub-groove (102), the projection of the upper solder layer (3) on the bottom surface of the heat sink (1) completely covering the projection of the lower solder layer (3) on the bottom surface of the heat sink (1), the thickness of the first gold layer (31) being 2.8 um, the thickness of the tin layer (32) being 2.6 um, and the thickness of the second gold layer (33) being 2.5 um, and the second gold layer (33) not protruding from the groove (101).

6. The pre-solder structure for a heat sink according to claim 5, characterized in that: A self-healing solder (4) is fixed on the surface of the solder layer (3), and the self-healing solder (4) is configured to self-repair the solder layer (3) when cracks occur in the solder layer (3).

7. The pre-set solder structure for a heat sink according to claim 6, characterized in that: The self-healing solder (4) comprises at least microcapsule particles, the microcapsule particles comprising a wall material layer and a self-healing material filled in the wall material layer, the wall material layer being any one of heat-sensitive, light-sensitive or stress-sensitive materials, and the self-healing material comprising at least liquid metal.

8. A semiconductor laser, characterized in that: It comprises a pre-set solder structure for a heat sink as described in any one of claims 5 to 7 and a laser chip, wherein the laser chip is fixed on the solder layer (3) by reflow soldering.

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