High-thermal-conductivity semiconductor laser heat dissipation structure based on diamond film

Abstract

The invention belongs to the technical field of semiconductors, and discloses a high-thermal-conductivity semiconductor laser heat dissipation structure based on a diamond film, which comprises a semiconductor laser, a transition heat sink, a metal-based base and a diamond film, wherein the semiconductor laser, the transition heat sink and the metal-based base are sequentially and adjacently stacked from top to bottom, the plane size of the transition heat sink is larger than that of the semiconductor laser, and the diamond film is tightly attached to the side wall face, except for the light-emitting face, of the semiconductor laser and the top face of the transition heat sink. And the bottom surface of the metal-based base is used for being connected with an external cooling structure. The LED lamp is high in heat dissipation performance and simple in structure.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor technology, specifically relating to a heat dissipation structure for a semiconductor laser with high thermal conductivity based on diamond thin film. Background Technology

[0002] As the power of semiconductor laser chips (hereinafter referred to as semiconductor lasers) continues to increase, the amount of waste heat generated by semiconductor lasers during operation is also increasing. If the waste heat cannot be effectively dissipated, it may affect the lifespan and beam quality of the laser, or even cause irreversible damage to the laser.

[0003] Current thermal designs for semiconductor lasers typically involve heat conduction from the laser to the environment via a heat sink. Heat generated inside the laser is first conducted vertically to the heat sink, then diffuses within it, and finally dissipates into the environment through air or water cooling. While this approach effectively dissipates heat, the heat dissipation path is very limited, and a significant portion of the heat sink remains underutilized. Summary of the Invention

[0004] This invention aims to at least partially solve one of the technical problems in related technologies. Therefore, one objective of this invention is to propose a high thermal conductivity semiconductor laser heat dissipation structure based on diamond thin film, which offers high heat dissipation performance and a simple structure.

[0005] According to an embodiment of the present invention, a high thermal conductivity semiconductor laser heat dissipation structure based on a diamond thin film includes a semiconductor laser, a transition heat sink, a metal substrate, and a diamond thin film; wherein the semiconductor laser, the transition heat sink, and the metal substrate are stacked adjacent to each other from top to bottom, the planar dimension of the transition heat sink is larger than the planar dimension of the semiconductor laser, the diamond thin film is closely attached to the side wall surface of the semiconductor laser (excluding the light-emitting surface) and the top surface of the transition heat sink, and the bottom surface of the metal substrate is used to connect with an external cooling structure.

[0006] Compared with existing technologies, the advantages of the high thermal conductivity semiconductor laser heat dissipation structure based on diamond thin film in this invention are as follows: Part of the heat generated in the active region of the semiconductor laser is directly conducted from the bottom of the semiconductor laser to the metal substrate through the transition heat sink; another part is indirectly conducted from the sidewall of the semiconductor laser to the transition heat sink via the high thermal conductivity diamond thin film, and then to the metal substrate. The heat is then conducted to the external cooling structure through the metal substrate, thereby effectively improving the heat dissipation rate, reducing the temperature of the semiconductor laser, and significantly improving the heat dissipation effect on the rear cavity surface of the semiconductor laser, which can increase the catastrophic damage threshold of the cavity surface. Furthermore, the high thermal conductivity semiconductor laser heat dissipation structure based on diamond thin film in this invention is relatively simple.

[0007] In some embodiments, the diamond film covers all sidewalls of the semiconductor laser except for the light-emitting surface.

[0008] In some embodiments, the thickness of the diamond film near the end face of the semiconductor laser is greater than its thickness at other locations.

[0009] In some embodiments, the thickness of the diamond film is 1 to 50 micrometers.

[0010] In some embodiments, the transition heat sink includes a first metal layer, an insulating thermally conductive substrate, and a second metal layer stacked sequentially from top to bottom; the first metal layer is located between the semiconductor laser and the diamond film and the insulating thermally conductive substrate, and the second metal layer is located between the insulating thermally conductive substrate and the metal base.

[0011] In some embodiments, the first metal layer has a trench extending through the thickness direction; the first metal layers located on both sides of the trench are electrically connected to the two electrodes of the semiconductor laser, respectively; if the diamond film is only disposed on the first metal layer located on one side of the trench, the first metal layers located on both sides of the trench are electrically connected to the power supply through power bonding wires; if the diamond film is disposed on the first metal layers located on both sides of the trench, the first metal layers located on both sides of the trench are electrically connected to the power supply through metal vias.

[0012] In some embodiments, the semiconductor laser and the second metal layer are respectively bonded to the corresponding first metal layer and the metal substrate by solder.

[0013] In some embodiments, the semiconductor laser and the transition heat sink are bonded together using either upright or flip-chip bonding.

[0014] In some embodiments, the metal base is a copper base.

[0015] In some embodiments, the planar dimensions of the metal base are greater than or equal to the planar dimensions of the transition heat sink.

[0016] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0017] Figure 1 This is a front view of the heat dissipation structure of a high thermal conductivity semiconductor laser based on a diamond thin film according to an embodiment of the present invention; Figure 2 This is a top view of a high thermal conductivity semiconductor laser heat dissipation structure based on a diamond thin film according to an embodiment of the present invention; Figure 3 This is a simulation result curve showing the relationship between the junction temperature of a semiconductor laser and the thickness of the diamond film in a high thermal conductivity laser heat dissipation structure based on a diamond film according to an embodiment of the present invention.

[0018] Figure Labels A high thermal conductivity semiconductor laser heat dissipation structure based on diamond thin film 1000; semiconductor laser 1; light-emitting surface 101; transition heat sink 2; first metal layer 201; trench 2011; insulating thermally conductive substrate 202; second metal layer 203; metal base 3; diamond thin film 4; bonding wire 5. Detailed Implementation

[0019] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0020] The following is combined with Figures 1 to 3 The present invention describes a high thermal conductivity semiconductor laser heat dissipation structure 1000 based on a diamond thin film according to an embodiment of the present invention.

[0021] like Figures 1 to 2 As shown, the high thermal conductivity semiconductor laser heat dissipation structure 1000 based on diamond thin film according to an embodiment of the present invention includes a semiconductor laser 1, a transition heat sink 2, a metal substrate 3, and a diamond thin film 4.

[0022] In this embodiment, the semiconductor laser 1, the transition heat sink 2, and the metal substrate 3 are stacked adjacent to each other from top to bottom. Because the transition heat sink 2 and the metal substrate 3 have good thermal conductivity, a portion of the heat generated in the active region of the semiconductor laser 1 is directly conducted from the bottom of the semiconductor laser 1 to the metal substrate 3 through the transition heat sink 2. The planar dimensions of the transition heat sink 2 are larger than those of the semiconductor laser 1; for example, the planar dimensions of the transition heat sink 2 are much larger than those of the semiconductor laser 1. This effectively increases the heat transfer area of ​​the transition heat sink 2, which is beneficial to improving the heat dissipation efficiency of the high thermal conductivity semiconductor laser heat dissipation structure 1000 based on diamond thin film in this embodiment. The diamond thin film 4 is closely attached to the sidewalls of the semiconductor laser 1 (excluding the light-emitting surface 101) and the top surface of the transition heat sink 2. Because the diamond thin film 4 is made of diamond material, which has high thermal conductivity (up to 2000 W·K), it is suitable for applications where diamond has high thermal conductivity. -1 ·m -1 The diamond film 4 has a low coefficient of thermal expansion (approximately 1 ppm / K). It is tightly bonded to the sidewall of the semiconductor laser 1 and the top surface of the transition heat sink 2. A portion of the heat generated in the active region of the semiconductor laser 1 is conducted from the sidewall of the semiconductor laser 1 through the diamond film 4 to the surface of the larger transition heat sink 2, and then from the transition heat sink 2 to the metal substrate 3. This effectively increases the heat transfer area and improves the heat dissipation rate of the semiconductor laser 1. The bottom surface of the metal substrate 3 is used to connect with an external cooling structure, which can be a heat-dissipating structure such as air cooling or water cooling. In this way, the metal substrate 3 can conduct heat to the external cooling structure, thereby achieving efficient heat dissipation.

[0023] Compared with existing technologies, the advantages of the high thermal conductivity semiconductor laser heat dissipation structure 1000 based on diamond thin film in this embodiment of the invention are as follows: Part of the heat generated in the active region of the semiconductor laser 1 is directly conducted from the bottom of the semiconductor laser 1 to the metal substrate 3 via the transition heat sink 2, and another part is indirectly conducted from the sidewall of the semiconductor laser 1 to the transition heat sink 2 via the high thermal conductivity diamond thin film 4, and then to the metal substrate 3. The heat is then conducted to the external cooling structure via the metal substrate 3, thereby effectively improving the heat dissipation rate, reducing the temperature of the semiconductor laser 1, and significantly improving the heat dissipation effect on the rear cavity surface of the semiconductor laser 1, which can increase the catastrophic damage threshold of the cavity surface of the semiconductor laser 1. Furthermore, the high thermal conductivity semiconductor laser heat dissipation structure 1000 based on diamond thin film in this embodiment of the invention is relatively simple.

[0024] In some embodiments, a diamond film 4 covers all sidewalls of the semiconductor laser 1 except for the light-emitting surface 101. This greatly increases the heat dissipation surface area of ​​the semiconductor laser 1 and improves the heat dissipation speed of the semiconductor laser 1.

[0025] In some embodiments, the thickness of the diamond film 4 near the end face of the semiconductor laser 1 is greater than the thickness at other locations, in order to improve the optical catastrophic damage threshold.

[0026] In some embodiments, the thickness of the diamond film 4 is 1 to 50 micrometers. A diamond film 4 with a thickness of 1 to 50 micrometers can effectively improve the heat dissipation of the semiconductor laser 1; the thicker the diamond film 4, the better the heat dissipation effect.

[0027] Figure 3 The curves showing the change in junction temperature of semiconductor laser 1 as the thickness of diamond film 4 varies from 3 micrometers to 12 micrometers are presented. Figure 3 As can be seen, for every 10 micrometers increase in the diamond film 4, the junction temperature of the semiconductor laser 1 decreases by approximately 1°C.

[0028] In some embodiments, the transition heat sink 2 includes a first metal layer 201, an insulating thermally conductive substrate 202, and a second metal layer 203 stacked sequentially from top to bottom. The insulating thermally conductive substrate 202 is made of an insulating, highly thermally conductive material. The first metal layer 201 is located between the semiconductor laser 1 and the diamond film 4 and the insulating thermally conductive substrate 202. The second metal layer 203 is located between the insulating thermally conductive substrate 202 and the metal base 3. This transition heat sink 2 has good thermal conductivity, and the first metal layer 201 and the second metal layer 203 achieve good insulation through the insulating thermally conductive substrate 202.

[0029] In some embodiments, the first metal layer 201 is provided with a trench 2011 extending through the thickness direction; the first metal layer 201 located on both sides of the trench 2011 is electrically connected to the two electrodes of the semiconductor laser 1 respectively; if the diamond film 4 is only disposed on the first metal layer 201 located on one side of the trench 2011, the first metal layers 201 located on both sides of the trench 2011 are electrically connected to the power supply through power bonding wires; if the diamond film 4 is disposed on the first metal layers 201 located on both sides of the trench 2011, the first metal layers 201 located on both sides of the trench 2011 are electrically connected to the power supply through metal vias.

[0030] In some embodiments, the semiconductor laser 1 and the second metal layer 203 are respectively bonded to the corresponding first metal layer 201 and metal substrate 3 by solder. That is, the semiconductor laser 1 is bonded to the first metal layer 201 of the transition heat sink 2 by solder, and the second metal layer 203 of the transition heat sink 2 is bonded to the metal substrate 3 by solder. Solder bonding has good thermal conductivity, stability, and high strength.

[0031] In some embodiments, the semiconductor laser 1 and the transition heat sink 2 are bonded using either upright mounting or flip-chip bonding. Upright mounting means that the active region of the semiconductor laser 1 is far from the transition heat sink 2, and heat from the semiconductor laser 1 enters the transition heat sink 2 through the epitaxial layer. Flip-chip bonding means that the active region of the semiconductor laser 1 is close to the transition heat sink 2, and heat can directly enter the transition heat sink 2.

[0032] In some embodiments, the metal base 3 is a copper base, which has good thermal conductivity.

[0033] In some embodiments, the planar dimensions of the metal base 3 are greater than or equal to the planar dimensions of the transition heat sink 2, which can further improve the heat dissipation effect.

[0034] The following is a specific example of a high thermal conductivity semiconductor laser heat dissipation structure 1000 based on a diamond thin film according to an embodiment of the present invention.

[0035] like Figure 1 and Figure 2 As shown, the high thermal conductivity semiconductor laser heat dissipation structure 1000 based on diamond thin film in this specific example includes a semiconductor laser 1, a diamond thin film 4, bonding wires, a transition heat sink 2, and a metal substrate 3.

[0036] The semiconductor laser 1 has a thickness of 8-100 micrometers, for example 90 micrometers; a width of 190-210 micrometers, for example 200 micrometers; and a length of 1100-1300 micrometers, for example 1200 micrometers. The transition heat sink 2 has a thickness of 440-460 micrometers, for example 450 micrometers; a length of 5600-5700 micrometers, for example 5650 micrometers; and a width of 4400-4600 micrometers, for example 4500 micrometers. The metal base 3 is a copper base with a thickness of 1.5-4 millimeters, for example 2 millimeters; a length and width of 7-9 millimeters, for example 8 millimeters; and a bottom surface temperature set to a constant 18-22°C, for example 20°C. The heat source for the semiconductor laser 1 is the active layer below the ridge, and the thermal power is set to 8W-12W, for example 10W.

[0037] The diamond thin film 4 is in close contact with the sidewall of the semiconductor laser 1 and the first metal layer 201 of the transition heat sink 2, and their shapes correspond. Figure 1 and Figure 2The diamond film 4 is used in the process. Solder is used to bond the semiconductor laser 1 to the transition heat sink 2 and the transition heat sink 2 to the metal substrate 3. A trench 201 is formed in the first metal layer 201 between the transition heat sink 2 and the semiconductor laser 1. One side of the trench 2011 directly contacts the bottom electrode of the semiconductor laser 1, while the other side is connected to the top electrode of the semiconductor laser 1 via bonding wires 5. The first metal layers 201 on both sides of the trench 2011 are connected to a power source (not shown in the figure) via power bonding wires, which then power the semiconductor laser 1. Furthermore, the diamond film 4 can be spread as far as possible over the surface of the transition heat sink 2 to improve the utilization rate of the heat sink and achieve better lateral heat conduction.

[0038] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A high-heat-conductivity semiconductor laser heat sink structure based on a diamond thin film, characterized by, The semiconductor laser, the transition heat sink, the metal base and the diamond film are sequentially and adjacently arranged from top to bottom, the planar size of the transition heat sink is larger than that of the semiconductor laser, the diamond film is closely arranged on the side wall surface of the semiconductor laser except the light emitting surface and the top surface of the transition heat sink, and the bottom surface of the metal base is used to connect with the external cooling structure.

2. The diamond thin film based high thermal conductivity semiconductor laser heat sink structure according to claim 1, wherein, The diamond film covers all the side wall surfaces of the semiconductor laser except the light emitting surface.

3. The diamond thin film based high thermal conductivity semiconductor laser heat sink structure of claim 1, wherein, The thickness of the diamond film near the end surface of the semiconductor laser is larger than that of the rest part.

4. The diamond thin film based high thermal conductivity semiconductor laser heat sink structure of claim 1, wherein, The thickness of the diamond film is 1-50 microns.

5. The diamond thin film based high thermal conductivity semiconductor laser heat sink structure of claim 1, wherein, The transition heat sink comprises a first metal layer, an insulating heat-conducting substrate and a second metal layer which are sequentially and adjacently arranged from top to bottom, the first metal layer is arranged between the semiconductor laser, the diamond film and the insulating heat-conducting substrate, and the second metal layer is arranged between the insulating heat-conducting substrate and the metal base.

6. The diamond thin film based high thermal conductivity semiconductor laser heat sink structure of claim 5, wherein, The first metal layer is provided with a groove penetrating in the thickness direction, the first metal layers on both sides of the groove are respectively electrically connected with two electrodes of the semiconductor laser, if the diamond film is arranged on the first metal layer on one side of the groove, the first metal layers on both sides of the groove are electrically connected with the power supply through the power supply bonding wire, and if the diamond film is arranged on the first metal layers on both sides of the groove, the first metal layers on both sides of the groove are electrically connected with the power supply through the metal via.

7. The diamond thin film based high thermal conductivity semiconductor laser heat sink structure of claim 6, wherein, The semiconductor laser and the second metal layer are respectively soldered to the corresponding first metal layer and the metal base.

8. The diamond thin film based high thermal conductivity semiconductor laser heat sink structure of claim 1, wherein, The semiconductor laser and the transition heat sink are connected by forward welding or flip-chip welding.

9. The high thermal conductivity diamond film based semiconductor laser heat spreading structure of claim 1, wherein, The metal base is a copper base.

10. The high thermal conductivity diamond film based semiconductor laser heat spreading structure of claim 1, wherein, The planar size of the metal base is larger than or equal to that of the transition heat sink.

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