Heat dissipation structure for improving heat dissipation performance of semiconductor laser and manufacturing method

Abstract

The invention provides a heat dissipation structure for improving the heat dissipation performance of a semiconductor laser and a manufacturing method, and relates to the technical field of semiconductor lasers. The heat dissipation structure comprises a bar, first water cooling plates are arranged on the N face and the P face of the bar respectively, and second water cooling plates are arranged on cleavage faces on the two sides of the bar respectively. A first liquid cooling channel, a first liquid inlet and a first liquid outlet are formed in the first water cooling plate, and a second liquid cooling channel, a second liquid inlet and a second liquid outlet are formed in the second water cooling plate. And the first liquid cooling channel is a macro channel. The second liquid cooling channel is a micro-channel of a linear structure, and the second liquid cooling channel is parallel to the cavity length direction of the bar. According to the heat dissipation structure for improving the heat dissipation performance of the semiconductor laser, the heat dissipation efficiency of the large-cavity long bar can be effectively improved, the performance and reliability of the laser can be improved, and the service life of the laser can be prolonged.

Description

Technical Field

[0001] This invention relates to the field of semiconductor laser technology, specifically to a heat dissipation structure and manufacturing method for improving the heat dissipation performance of semiconductor lasers. Background Technology

[0002] With the rapid development of modern technology, semiconductor lasers play an irreplaceable role in industrial processing, medical aesthetics, defense technology, and scientific research. Currently, in high-power applications, semiconductor laser bars commonly employ a large cavity length (i.e., a longer distance between the front and rear cavity surfaces) design to achieve higher output power. However, while this design increases output power, it also generates more heat. Existing single-sided heat sinks are insufficient to meet heat dissipation requirements, significantly reducing heat dissipation efficiency. This not only restricts laser performance improvement but also directly affects device reliability and lifespan. Summary of the Invention

[0003] To address the aforementioned issues, this application provides a heat dissipation structure that improves the heat dissipation performance of semiconductor lasers. This structure can effectively enhance the heat dissipation efficiency of large-cavity long bar lasers, thereby improving the performance, reliability, and lifespan of the laser.

[0004] The technical solution adopted by this invention to solve its technical problem is: A heat dissipation structure for improving the heat dissipation performance of a semiconductor laser includes a bar, wherein a first water-cooling plate is disposed on the N-side and P-side of the bar, and a second water-cooling plate is disposed on the cleavage surfaces on both sides of the bar. The first water-cooled plate is provided with a first liquid cooling channel, a first liquid inlet and a first liquid outlet, and the second water-cooled plate is provided with a second liquid cooling channel, a second liquid inlet and a second liquid outlet. The first liquid cooling channel is a macro channel; The second liquid cooling channel is a microchannel with a straight structure, and the second liquid cooling channel is parallel to the length direction of the bar strip.

[0005] Furthermore, the first liquid cooling channel has a serpentine structure.

[0006] Furthermore, the second liquid cooling channel sequentially includes an inlet manifold, a main heat dissipation area, and an outlet manifold. Within the main heat dissipation area, several partitions are evenly distributed along the thickness direction of the bar, and the partitions divide the space of the main heat dissipation area into several microchannels.

[0007] Furthermore, the second liquid inlet is located on the side of the second water-cooled plate facing the front cavity of the bar, and the second liquid outlet is located on the side of the second water-cooled plate facing the rear cavity of the bar.

[0008] Furthermore, the bar includes several mini bars, and a ceramic substrate is disposed between two adjacent mini bars.

[0009] Furthermore, a plurality of third heat dissipation grooves are provided on the N-side of the bar, and heat sink strips are provided in the third heat dissipation grooves, and the heat sink strips are flush with the N-side of the bar.

[0010] Furthermore, the depth of the third heat dissipation groove is less than the substrate thickness of the bar.

[0011] Furthermore, the width of the third heat dissipation groove is 10-30μm, and the distance between two adjacent third heat dissipation grooves is 40-60μm.

[0012] A method for fabricating a heat dissipation structure to improve the heat dissipation performance of a semiconductor laser includes the following steps: S1, cleavage lines are etched on the chip according to the design dimensions of the mini bar; S2, bonding the wafer to the substrate and thinning it to the designed thickness; S3, a third heat sink is etched on the N-side of the chip; S4, metal is prepared on the N-side of the wafer; S5. After debonding the wafer, annealing is performed to fabricate the N-side electrode. S6. Following the cleavage lines of step S6, the wafer is dissected into mini bars, and the front and rear cavity surfaces of the mini bars are coated. S7, the heat sink is welded into the third heat dissipation groove; S8, arrange the mini bar and ceramic substrate according to the design, and fix them to the two first water-cooling plates by welding to obtain a primary encapsulation component; S9, a second water-cooling plate is welded to both sides of the primary encapsulation component.

[0013] Furthermore, in step S4, the thickness of the vapor-deposited metal is 800 nanometers.

[0014] The beneficial effects of this invention are: 1. This application provides a heat dissipation structure to improve the heat dissipation performance of a semiconductor laser. The heat dissipation structure includes a first water-cooling plate disposed on the upper and lower sides of the bar and a second water-cooling plate disposed on the cleavage surface of the bar. Compared with the traditional method of welding a heat sink on one side of the bar for heat dissipation, it can effectively improve the heat dissipation efficiency. Even for bars with large cavity lengths, the bar can be kept within the normal temperature range, thereby improving the performance of the laser and avoiding the impact of poor heat dissipation on the reliability and service life of the device.

[0015] 2. In the heat dissipation structure for improving the heat dissipation performance of a semiconductor laser provided in this application embodiment, the laser bar is divided into several mini-lasers, and a ceramic substrate is placed between two adjacent mini-lasers. Because the ceramic substrate has good thermal conductivity and insulation, it not only ensures the independence of each mini-laser but also allows the heat generated by the mini-lasers to be quickly and effectively transferred to the first water-cooling plates on the upper and lower sides. This effectively improves the overall heat dissipation efficiency of the laser bar compared to opening multiple heat dissipation channels in the middle of the original laser bar.

[0016] 3. The heat dissipation structure for improving the heat dissipation performance of semiconductor lasers provided in this application provides a heat dissipation structure by opening multiple third heat dissipation grooves on the N side of the bar and setting heat sink strips for heat dissipation in the third heat dissipation grooves. On the one hand, this is equivalent to increasing the base area of ​​the N side of the bar and the first water-cooled plate located on one side of the N side. On the other hand, it can quickly and effectively dissipate the heat generated inside the bar, thereby effectively improving the heat dissipation efficiency. Attached Figure Description

[0017] Figure 1 A three-dimensional structural diagram of a heat dissipation structure for improving the heat dissipation performance of a semiconductor laser, provided for an embodiment of this application; Figure 2 for Figure 1 A magnified structural diagram of part A in the middle; Figure 3 A top view of a heat dissipation structure for improving the heat dissipation performance of a semiconductor laser, provided in an embodiment of this application; Figure 4 for Figure 3 AA section view in the middle; Figure 5 for Figure 4 A magnified structural diagram of part B in the middle section; Figure 6 An exploded view of a heat dissipation structure for improving the heat dissipation performance of a semiconductor laser, provided in an embodiment of this application; Figure 7 This is a schematic diagram of the installation structure of the heat sink strip; Figure 8 for Figure 7 A magnified structural diagram of section C; Figure 9 An exploded view of the first water-cooled plate; Figure 10 This is a schematic diagram of the structure of the first water-cooled substrate; Figure 11 An exploded view of the second water-cooled plate; Figure 12 This is a schematic diagram of the structure of the second water-cooled substrate.

[0018] In the figure: 1. First water-cooled plate; 11. First liquid-cooled channel; 12. First liquid inlet; 13. First liquid outlet; 14. First water-cooled substrate; 141. First groove; 142. First heat dissipation groove; 15. First cover plate; 2. Second water-cooled plate; 21. Second liquid-cooled channel; 22. Second liquid inlet; 23. Second liquid outlet; 24. Second water-cooled substrate; 241. Second groove; 242. Partition; 25. Second cover plate; 3. Mini heatsink; 31. N-side; 311. Third heatsink; 32. P-side; 33. Front cavity surface; 34. Rear cavity surface; 35. Cleavage surface; 4. Ceramic substrate; 5. Heat sink strip. Detailed Implementation

[0019] To enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be described in detail below with reference to the accompanying drawings. The described embodiments are merely a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort should fall within the protection scope of this application.

[0020] To facilitate understanding of the specific embodiments of this application, a coordinate system is now defined as follows: Figure 1 As shown, the left and right directions are horizontal, the front and back directions are vertical, and the up and down directions are vertical.

[0021] like Figure 1 and Figure 6 As shown, a heat dissipation structure for improving the heat dissipation performance of a semiconductor laser includes a cooling bar. First water-cooling plates 1 are respectively disposed on the upper and lower sides of the cooling bar, and second water-cooling plates 2 are respectively disposed on the cleavage surfaces 35 on both sides of the cooling bar. The first water-cooling plate 1 has a first liquid cooling channel 11, a first liquid inlet 12, and a first liquid outlet 13, which are respectively connected to the first liquid cooling channel 11. The second water-cooling plate 2 has a second liquid cooling channel 21, a second liquid inlet 22, and a second liquid outlet 23, which are respectively connected to the second liquid cooling channel 21. The first liquid inlet 12 and the second liquid inlet 22 are respectively connected to the outlet of a refrigeration unit (not shown in the figure) via pipes (not shown in the figure), and the first liquid outlet 13 and the second liquid outlet 23 are respectively connected to the inlet of the refrigeration unit via pipes (not shown in the figure).

[0022] During operation, the coolant, after being cooled by the refrigeration unit, enters the first water-cooled plate 1 and the second water-cooled plate 2 through the first liquid inlet 12 and the second liquid inlet 22 respectively, and flows along the first liquid cooling channel 11 and the second liquid cooling channel 21. During the flow, heat exchange is completed, thereby removing the heat generated by the bar. Then, the coolant flows out from the first liquid outlet 13 and the second liquid outlet 23 respectively, and flows back to the refrigeration unit along the pipeline for cooling again, thus completing one heat dissipation cycle.

[0023] The first water-cooled plate 1 and the second water-cooled plate 2 form a heat dissipation structure surrounding the bar, which can simultaneously cool and dissipate heat on the N-side 31, P-side 32 and the cleavage surfaces 35 on both sides of the bar. Compared with the traditional method of setting heat sinks for heat dissipation on the N-side 31 or P-side 32 of the bar, it can effectively improve heat dissipation efficiency, and even for bar with a large cavity length, it can avoid the problem of local overheating (especially the front cavity surface 33).

[0024] like Figure 9 and Figure 10 As shown, the first liquid cooling channel 11 within the first water-cooled plate 1 is a macrochannel and has a serpentine structure. The first liquid inlet 12 and the first liquid outlet 13 are both located on the side of the first water-cooled plate 1 facing the rear cavity surface 34 of the bar. Figure 1 In the coordinate system shown, the first liquid inlet 12 and the first liquid outlet 13 are both located on the rear side of the first water-cooling plate 1.

[0025] In one specific embodiment, the first water-cooled plate 1 in this embodiment includes a first water-cooled substrate 14. The first water-cooled substrate 14 has a first groove 141 with a square structure, and a first heat dissipation groove 142 with a serpentine structure is provided within the first groove 141. A first liquid inlet 12, communicating with the first heat dissipation groove 142, is provided on the rear sidewall of the first water-cooled substrate 14 at one end of the first heat dissipation groove 142, and a first liquid outlet 13, communicating with the first heat dissipation groove 142, is provided on the other end of the rear sidewall of the first water-cooled substrate 14. A first cover plate 15 is provided within the first groove 141, and the first cover plate 15 fits into the first groove 141 and is fixedly connected to the first water-cooled substrate 14 by welding. The open side of the first heat dissipation groove 142 is blocked by the first cover plate 15, forming the first liquid cooling channel 11.

[0026] Both the first water-cooled substrate 14 and the first cover plate 15 are made of materials with good thermal conductivity, such as copper, aluminum, and aluminum alloys.

[0027] In one specific implementation, the upper and lower sides (i.e., N-side 31 and P-side 32) of the bar are fixedly connected to the first water-cooled substrate 14 of the first water-cooled plate 1 by welding. This ensures that the bar is in close contact with the first water-cooled plate 1, thereby guaranteeing the heat dissipation effect.

[0028] like Figure 11 and Figure 12 As shown, the second liquid cooling channel 21 within the second water-cooled plate 2 is a microchannel and has a straight structure parallel to the length direction of the bar. The second liquid inlet 22 and the second liquid outlet 23 are located at opposite ends of the second water-cooled plate 2 along the length direction of the bar cavity.

[0029] In one specific implementation, the second liquid cooling channel 21 in this embodiment sequentially includes an inlet manifold area, a main heat dissipation area, and an outlet manifold area. A plurality of partitions 242 are evenly distributed along the thickness direction of the bar in the main heat dissipation area, dividing the space of the main heat dissipation area into a plurality of microchannels. The second liquid inlet 22 is located on one side of the inlet manifold area and is connected to it. The second liquid outlet 23 is located on one side of the outlet manifold area and is connected to it.

[0030] As one specific implementation method, such as Figure 3 , Figure 4 and Figure 5 As shown, in this embodiment, the main heat dissipation area is provided with four partitions 242, which divide the space of the main heat dissipation area into five microchannels, and the width of the microchannels is 0.2-0.3mm.

[0031] In one specific embodiment, the second water-cooled plate 2 in this embodiment includes a second water-cooled substrate 24. A second groove 241 is provided on the outer side of the second water-cooled substrate 24 (with the side facing the barbed cleavage surface 35 as the inner side). A second cover plate 25 for sealing the second groove 241 is provided on the outer side of the second water-cooled substrate 24, and the second cover plate 25 is fixedly connected to the second water-cooled substrate 24 by welding. The second groove 241 extends vertically (according to...) Figure 1 Four partitions 242 are evenly distributed in the coordinate system shown, and the end face of the suspended end of the partition 242 is flush with the outer surface of the second water-cooled substrate 24. There is a distance between the front and rear ends of the partition 242 and the side wall of the second groove 241.

[0032] This application combines a relatively large macrochannel with a microchannel that has high heat dissipation efficiency, which not only ensures the heat dissipation effect, but also effectively reduces the sensitivity of the microchannel to water quality due to the linear structure of the microchannel.

[0033] Furthermore, the second liquid inlet 22 is located on the side of the second water-cooled plate 2 facing the front cavity surface 33 of the bar, and the second liquid outlet 23 is located on the side of the second water-cooled plate 2 facing the rear cavity surface 34 of the bar.

[0034] The reason for this design is that the front cavity surface 33 is the main heat-generating point during operation. By setting the second liquid inlet 22 on the side of the second water-cooled plate 2 facing the front cavity surface 33, the coolant can first exchange heat with the cleavage surface 35 on the side close to the front cavity surface 33, thereby ensuring the heat exchange effect and achieving targeted heat dissipation.

[0035] Furthermore, such as Figure 1 and Figure 2 As shown, the bar includes several mini bars 3, and a ceramic substrate 4 is disposed between two adjacent mini bars 3. The upper side of the ceramic substrate 4 is flush with the upper side of the bar, and the lower side of the ceramic substrate 4 is flush with the lower side of the bar.

[0036] In one specific implementation, the bar in this embodiment includes four mini bar strips 3, with a ceramic substrate 4 disposed between two adjacent mini bar strips 3. That is, the bar is composed of four mini bar strips 3 and three ceramic substrates 4.

[0037] The thickness of the ceramic substrate 4 is 10-20 μm.

[0038] In one specific embodiment, the thickness of the ceramic substrate 4 in this example is 20 μm.

[0039] Furthermore, a plurality of third heat dissipation grooves 311 are evenly distributed on the N-side 31 of the bar, meaning that each mini bar 3 is provided with a third heat dissipation groove 311. A heat sink 5 is disposed within the third heat dissipation groove 311, and the side of the heat sink 5 facing away from the third heat dissipation groove 311 is flush with the N-side 31 of the bar. That is, one side of the heat sink 5 contacts the first water-cooling plate 1, and the other side extends into the bar. This increases the heat dissipation area and improves the heat dissipation effect, and also directly conducts heat from inside the bar, shortening the heat conduction distance and further enhancing the heat dissipation effect.

[0040] In one specific implementation, the third heat dissipation groove 311 described in this embodiment penetrates the bar along the cavity length direction of the bar.

[0041] The depth of the third heat sink 311 is less than the thickness of the substrate of the bar (located on the N side of the bar).

[0042] In one specific implementation, the depth of the third groove in this embodiment is 40-60μm.

[0043] The width of the third heat dissipation groove 311 is 10-30μm, and the distance between two adjacent third heat dissipation grooves 311 is 40-60μm.

[0044] In one specific implementation, the width of the third heat dissipation groove 311 in this embodiment is 20μm, and the distance between two adjacent third heat dissipation grooves 311 is 50μm.

[0045] A method for fabricating a heat dissipation structure to improve the heat dissipation performance of a semiconductor laser includes the following steps: S1, cleavage lines are etched on the wafer according to the design dimensions of mini bar 3.

[0046] S2 involves bonding the wafer to a sapphire substrate and then thinning the wafer to the designed thickness through grinding and polishing.

[0047] In one specific implementation, the wafer in this embodiment is designed to have a thickness of 120 μm.

[0048] S3, a third heat sink 311 is etched on the N-side 31 of the chip.

[0049] S4 uses a vacuum evaporation process to deposit metal on the N-side 31 of the wafer. The metal is one or more of titanium, platinum, gold, nickel, and germanium, and the thickness of the deposited metal is 800 nanometers.

[0050] S5. After the wafer is debonded, it is placed in a rapid annealing furnace for annealing to produce the N-side 31 electrode.

[0051] S6, the wafer is separated into mini bars 3, and an electron beam evaporation coating device is used to coat the front cavity surface 33 and the rear cavity surface 34 of the mini bars 3. The coating material is one or more of silicon oxide, aluminum oxide, and titanium oxide.

[0052] S7, the heat sink 5 is welded to the third heat sink 311 by gold-tin welding.

[0053] S8, arrange the mini bar strip 3 and ceramic substrate 4 according to the design, and fix them to the two first water-cooling plates 1 by welding to obtain a primary encapsulation component.

[0054] S9, the second water-cooled plate 2 is welded to both sides of the first encapsulation component obtained in step S8, and the second water-cooled plate 2 is attached to the outer cleavage surface 35 of the mini bar strips 3 located at both ends.

[0055] Other embodiments obtained by those skilled in the art based on the embodiments provided in this application by combining, splitting, or reorganizing the embodiments of this application do not exceed the protection scope of this application.

[0056] The above detailed embodiments have provided a detailed explanation of the purpose, technical solutions, and beneficial effects of the embodiments of this application. The above are merely specific embodiments of the embodiments of this application and are not intended to limit the protection scope of the embodiments of this application. That is, any modifications, equivalent substitutions, improvements, etc., made on the basis of the embodiments of this application should be included within the protection scope of the embodiments of this application.

Claims

1. A heat dissipation structure for improving heat dissipation performance of a semiconductor laser, comprising a bar, characterized in that: The N face (31) and P face (32) of the bar are respectively provided with a first water cooling plate (1), and the cleavage plane (35) on both sides of the bar is respectively provided with a second water cooling plate (2); The first water cooling plate (1) is internally provided with a first liquid cooling channel (11), a first liquid inlet (12) and a first liquid outlet (13), and the second water cooling plate (2) is internally provided with a second liquid cooling channel (21), a second liquid inlet (22) and a second liquid outlet (23); The first liquid cooling channel (11) is a macro channel; The second liquid cooling channel (21) is a micro channel in a straight line structure, and the second liquid cooling channel (21) is parallel to the cavity length direction of the bar.

2. The heat dissipation structure for improving heat dissipation performance of a semiconductor laser according to claim 1, characterized in that: The first liquid cooling channel (11) is in a serpentine structure.

3. The heat dissipation structure for improving heat dissipation performance of a semiconductor laser according to claim 1, characterized in that: The second liquid cooling channel (21) sequentially includes a liquid inlet convergence area, a main heat dissipation area and a liquid outlet convergence area, a plurality of partitions (242) are uniformly arranged in the main heat dissipation area along the thickness direction of the bar, and the partitions (242) divide the space of the main heat dissipation area into a plurality of micro channels.

4. The heat dissipation structure for improving heat dissipation performance of a semiconductor laser according to claim 1, characterized in that: The second liquid inlet (22) is located on one side of the second water cooling plate (2) facing the front cavity face (33) of the bar, and the second liquid outlet (23) is located on one side of the second water cooling plate (2) facing the rear cavity face (34) of the bar.

5. The heat dissipation structure for improving heat dissipation performance of a semiconductor laser according to claim 1, characterized in that: The bar includes a plurality of mini bars (3), and a ceramic substrate (4) is arranged between two adjacent mini bars (3).

6. The heat dissipation structure for improving heat dissipation performance of a semiconductor laser according to claim 5, characterized in that: A plurality of third heat dissipation grooves (311) are arranged on the N face (31) of the bar, a heat sink strip (5) is arranged in the third heat dissipation groove (311), and the heat sink strip (5) is flush with the N face (31) of the bar.

7. The heat dissipation structure for improving heat dissipation performance of a semiconductor laser according to claim 6, characterized in that: The depth of the third heat dissipation groove (311) is less than the substrate thickness of the bar.

8. The heat dissipation structure for improving heat dissipation performance of a semiconductor laser according to claim 6, characterized in that: The width of the third heat dissipation groove (311) is 10-30 μm, and the distance between two adjacent third heat dissipation grooves (311) is 40-60 μm.

9. The method for manufacturing the heat dissipation structure for improving the heat dissipation performance of a semiconductor laser as claimed in any one of claims 6 to 8, wherein: The method comprises the following steps, S1, etching a cleavage line on a wafer according to the design size of the mini bar (3); S2, bonding the wafer on a substrate and thinning to a design thickness; S3, etching a third heat dissipation groove (311) on the N face (31) of the wafer; S4, preparing a metal on the N face (31) of the wafer; S5, after the wafer is unbonded, annealing treatment is performed to manufacture an N face (31) electrode; S6, according to the cleavage line of step S6, the wafer is separated into mini bars (3), and the front cavity face (33) and the rear cavity face (34) of the mini bar (3) are plated; S7, welding a heat sink strip (5) in the third heat dissipation groove (311); S8, arranging the mini bar (3) and the ceramic substrate (4) according to the design, and fixedly connecting them with two first water cooling plates (1) by welding to obtain a primary packaging assembly; S9, welding a second water cooling plate (2) on both sides of the primary packaging assembly.

10. The method of claim 9, wherein the method further comprises: forming a plurality of grooves on the substrate; and forming a plurality of grooves on the semiconductor laser. In step S4, the thickness of the evaporated metal is 800 nanometers.

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