GaN blue laser

Abstract

The invention discloses a GaN blue laser, which comprises a chip, a shunting assembly and a heat sink, and is characterized in that the chip comprises a substrate, and a plurality of micro-channels are formed on one side of the substrate through etching; each micro-channel extends along a first direction; the shunting assembly is arranged on one side, where the micro-channel is formed, of the substrate and is connected with the substrate; a cooling working medium inlet and a cooling working medium outlet are formed in the side, away from the substrate, of the flow dividing assembly. A first flow channel and a second flow channel extending in the second direction are formed in the side, connected with the substrate, of the flow dividing assembly. The first flow channel is communicated with the cooling working medium inlet, the second flow channel is communicated with the cooling working medium outlet, and each micro-flow channel is communicated with the first flow channel and the second flow channel; the heat sink is arranged on the side, away from the substrate, of the chip and connected with the chip. According to the invention, double-sided heat dissipation of the GaN blue laser chip is realized, and the junction temperature of the GaN blue laser chip during working is effectively reduced.

Description

Technical Field

[0001] This invention relates to the field of heat dissipation technology for electronic devices with extremely high heat flux density, and in particular to a GaN blue laser. Background Technology

[0002] GaN blue lasers are widely used in laser processing, laser displays, and other fields, but heat dissipation issues during high-power operation severely limit their performance and reliability. When the laser power reaches the several watts level, poor heat dissipation can lead to a sharp rise in junction temperature, resulting in increased threshold current, decreased output power, and deterioration of beam quality, while also significantly shortening the device's lifespan.

[0003] Traditional heat sinks primarily rely on their large surface area to conduct and convect heat to the surrounding environment. However, heat sinks have limited thermal conductivity and are constrained by installation space, making their heat dissipation efficiency insufficient for high power density applications. Air cooling uses fans to force airflow and remove heat, resulting in a relatively simple structure. However, with increasing laser power, air cooling is insufficient to effectively reduce chip junction temperatures. While microchannel cooling has been studied in recent years, it is mostly integrated with the laser after the heat sink body. Heat transfer requires multiple medium transitions, and the cumulative thermal resistance limits efficiency improvements. Summary of the Invention

[0004] This invention aims to at least solve one of the technical problems existing in the prior art. Therefore, one object of this invention is to provide a GaN blue laser that addresses the problem of low heat dissipation efficiency in existing GaN blue lasers.

[0005] This invention proposes a GaN blue laser, which includes a chip, a shunt assembly, and a heat sink. The chip includes a substrate, on one side of which multiple microchannels are formed by etching. Each microchannel extends along a first direction. The shunt assembly is disposed on the side of the substrate where the microchannels are formed and is connected to the substrate. A cooling medium inlet and a cooling medium outlet are formed on the side of the shunt assembly away from the substrate, and a first channel and a second channel extending along a second direction are formed on the side of the shunt assembly in contact with the substrate. The first channel is connected to the cooling medium inlet, and the second channel is connected to the cooling medium outlet, and each microchannel is connected to both the first and second channels. The heat sink is disposed on the side of the chip away from the substrate and is connected to the chip.

[0006] The GaN blue laser of the present invention achieves heat dissipation through conduction by transferring heat from one side of the active region of the chip to the outside via a highly thermally conductive heat sink; and through convection cooling via microchannels in the chip's substrate and the cooling medium, heat is dissipated from the other side. This achieves double-sided heat dissipation of the chip, effectively reducing the junction temperature during chip operation. The chip substrate, by etching microchannels, shortens the heat transfer path, reduces thermal resistance in intermediate stages, and improves heat dissipation efficiency.

[0007] According to some embodiments of the present invention, the flow splitting assembly includes a first flow splitter and a second flow splitter, the second flow splitter being connected to a substrate, and the first flow splitter being connected to the second flow splitter; wherein, a cooling medium inlet and a cooling medium outlet are formed on the side of the first flow splitter opposite to the second flow splitter; a third flow channel and a fourth flow channel are formed on the side of the first flow splitter connected to the second flow splitter; the third flow channel is connected to the cooling medium inlet, and the fourth flow channel is connected to the cooling medium outlet; a first flow channel and a second flow channel are formed on the side of the second flow splitter connected to the substrate; a flow splitting inlet and a flow splitting outlet are formed on the side of the second flow splitter connected to the first flow splitter, the flow splitting inlet being connected to the first flow channel and the third flow channel, and the flow splitting outlet being connected to the second flow channel and the fourth flow channel.

[0008] According to some embodiments of the present invention, the second flow channel is constructed as two, respectively disposed on both sides of the first flow channel.

[0009] According to some embodiments of the present invention, the diversion inlet and / or diversion outlet are both configured as a plurality of such inlets and outlets spaced apart along a second direction.

[0010] According to some embodiments of the present invention, portions of the fourth flow channel are disposed on both sides of the third flow channel and are directly opposite the diversion outlet.

[0011] According to some embodiments of the present invention, a portion of the fourth flow channel is disposed outside the end of the third flow channel and communicates with the cooling medium outlet; the cooling medium outlet is disposed directly opposite the end of the third flow channel.

[0012] According to some embodiments of the present invention, the aperture of the cooling medium inlet gradually decreases along the cooling medium inflow direction, and the aperture of the cooling medium outlet gradually increases along the cooling medium outflow direction.

[0013] According to some embodiments of the present invention, the first splitter is constructed as a symmetrical structure, and the axis of symmetry of the first splitter extends along a second direction; the second splitter is constructed as a symmetrical structure, and the axis of symmetry of the second splitter extends along a second direction.

[0014] According to some embodiments of the present invention, the chip and the heat sink are connected by flip-chip bonding.

[0015] According to some embodiments of the present invention, the heat sink includes a substrate and a metal layer, the metal layer being disposed on both sides of the substrate, wherein one side of the metal layer is connected to the chip.

[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] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a schematic diagram of the structure of a GaN blue laser according to some embodiments of the present invention; Figure 2 This is a schematic diagram of one side structure of the first shunt according to some embodiments of the present invention; Figure 3 This is a schematic diagram of the other side of the first shunt according to some embodiments of the present invention; Figure 4 This is a schematic diagram of one side structure of the second splitter according to some embodiments of the present invention; Figure 5 This is a schematic diagram of the other side structure of the second shunt according to some embodiments of the present invention; Figure 6 This is a schematic diagram of the structure of a substrate according to some embodiments of the present invention; Figure 7 This is a schematic diagram of the structure of a heat sink according to some embodiments of the present invention.

[0018] Figure label: Chip 1; Substrate 11; Microchannel 12; First flow divider 2; Cooling medium inlet 21; Cooling medium outlet 22; Third flow channel 23; Fourth flow channel 24; Second flow divider 3; Flow divider inlet 31; Flow divider outlet 32; First flow channel 33; Second flow channel 34; Heat sink 4; substrate 41; metal layer 42; solder layer 43. Detailed Implementation

[0019] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown 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 are only used to explain the present invention, and should not be construed as limiting the present invention.

[0020] The following is for reference. Figures 1-7 A GaN blue laser according to an embodiment of the present invention is described.

[0021] This invention proposes a GaN blue laser, which includes a chip 1, a shunt assembly, and a heat sink 4. The chip 1 includes a substrate 11, on one side of which a plurality of microchannels 12 are formed by etching, each microchannel 12 extending along a first direction. The shunt assembly is disposed on the side of the substrate 11 where the microchannels 12 are formed and is connected to the substrate 11. A cooling medium inlet 21 and a cooling medium outlet 22 are formed on the side of the shunt assembly away from the substrate 11. A first channel 33 and a second channel 34 extending along a second direction are formed on the side of the shunt assembly that is in contact with the substrate 11. The first channel 33 is connected to the cooling medium inlet 21, and the second channel 34 is connected to the cooling medium outlet 22. Each microchannel 12 is connected to both the first channel 33 and the second channel 34. The heat sink 4 is disposed on the side of the chip 1 away from the substrate 11 and is connected to the chip 1.

[0022] According to the GaN blue laser of the present invention, by directly etching microchannels 12 on the substrate 11 of chip 1, the heat conduction path can be significantly shortened, interface thermal resistance can be avoided, and heat dissipation efficiency can be significantly improved. A shunt assembly is provided on one side of chip 1. The cooling medium flows in from the cooling medium inlet 21 of the shunt assembly, flows sequentially through the first channel 33, the microchannel 12 and the second channel 34, and flows out from the cooling medium outlet 22. When flowing through the microchannel 12, heat is carried away from the channel wall by forced convection, thereby achieving heat dissipation. A heat sink 4 is provided on the other side of chip 1. The heat sink 4 is made of a high thermal conductivity material. It uses its high thermal conductivity to transfer and diffuse the heat concentrated in the active area of ​​chip 1 outward through thermal conduction, thereby achieving heat dissipation. In some embodiments, the first direction is perpendicular to the second direction. The first direction is the width direction of chip 1 and the second direction is the length direction of chip 1. The cooling medium naturally disperses in the first channel 33 to each microchannel 12 and flows naturally along the extension direction of the microchannel 12, and then converges in the second channel 34.

[0023] According to the GaN blue laser of the present invention, on the one hand, heat from the active region of chip 1 is transferred from one side to the outside through a heat sink 4 with high thermal conductivity, achieving heat conduction heat dissipation; on the other hand, heat is dissipated from the other side through convection heat dissipation between the microchannels 12 provided in the substrate 11 of chip 1 and the cooling medium. This achieves double-sided heat dissipation of chip 1, effectively reducing the junction temperature of chip 1 during operation. Specifically, the substrate 11 of chip 1, by etching to form the microchannels 12, can shorten the heat transfer path, reduce the thermal resistance of intermediate links, and improve heat dissipation efficiency.

[0024] In some embodiments, such as Figure 1 As shown, the shunt assembly, chip 1, and heat sink 4 are arranged sequentially along the height direction. The shunt assembly is located on the upper side of chip 1 to conduct heat away from above; the heat sink 4 is located on the lower side of chip 1 to transfer heat from the active area downwards. Both the first and second directions are horizontal.

[0025] According to some embodiments of the present invention, the flow splitting assembly includes a first flow splitter 2 and a second flow splitter 3, the second flow splitter 3 being connected to a substrate 11, and the first flow splitter 2 being connected to the second flow splitter 3; wherein, a cooling medium inlet 21 and a cooling medium outlet 22 are formed on the side of the first flow splitter 2 facing away from the second flow splitter 3; a third flow channel 23 and a fourth flow channel 24 are formed on the side of the first flow splitter 2 connected to the second flow splitter 3; the third flow channel 23 is connected to the cooling medium inlet 21, and the fourth flow channel 24 is connected to the cooling medium outlet 22; a first flow channel 33 and a second flow channel 34 are formed on the side of the second flow splitter 3 connected to the substrate 11; a flow splitting inlet 31 and a flow splitting outlet 32 ​​are formed on the side of the second flow splitter 3 connected to the first flow splitter 2, the flow splitting inlet 31 being connected to the first flow channel 33 and the third flow channel 23, and the flow splitting outlet 32 ​​being connected to the second flow channel 34 and the fourth flow channel 24. This embodiment establishes a medium path for the cooling medium to enter and exit the microchannel 12 by setting two flow dividers: a first flow divider 2 and a second flow divider 3. The cooling medium enters the first flow divider 2 from the cooling medium inlet 21, then flows sequentially through the third channel 23, the diversion inlet 31, and the first channel 33 to the microchannel 12. It then flows sequentially through the second channel 34, the diversion outlet 32, and the fourth channel 24 before exiting from the cooling medium outlet 22. The first flow divider 2 primarily functions as the entry and exit point for the cooling medium, while the second flow divider 3 primarily optimizes the flow distribution of the cooling medium. Setting two flow dividers ensures a more uniform distribution of the cooling medium, avoiding poor localized heat dissipation. This embodiment, by setting the first flow divider 2 and the second flow divider 3, achieves stable and uniform flow of the cooling medium, improving the heat dissipation efficiency of the GaN blue laser.

[0026] Furthermore, the first shunt 2 and the second shunt 3 are connected as a single unit via waterproof mounting, overlapping in the height direction of the GaN blue laser; the second shunt 3 is mounted and connected to the substrate 11; both the shunt assembly and the chip 1 are sealed. During assembly, the first shunt 2 and the second shunt 3 are encapsulated first, and then the encapsulated shunt assembly is mounted onto the substrate 11 of the chip 1.

[0027] According to some embodiments of the present invention, two second flow channels 34 are constructed, respectively disposed on both sides of the first flow channel 33. In this embodiment, as... Figure 5As shown, the first flow channel 33 is positioned between the two second flow channels 34, highly overlapping with the active region of chip 1. The active region of the chip is the main heat-generating area of ​​the GaN blue laser. When the cooling medium enters each microchannel 12 from the first flow channel 33, it first covers the high-heat area to form convective heat dissipation, and then flows naturally to both ends of the microchannel 12, continuing to carry away the heat from the outer periphery of chip 1. After accumulating in the second flow channel 34, it flows out of the shunt assembly. In this embodiment, the cooling medium preferentially impacts the active region, further shortening the heat transfer path. By accelerating heat removal through strong convective heat transfer, the heat dissipation effect of the cooling medium on chip 1 can be optimized, improving heat dissipation efficiency and maintaining the temperature stability of chip 1.

[0028] Furthermore, such as Figure 6 As shown, the microchannel 12 is constructed as a rectangular cross-section channel that facilitates etching. Multiple microchannels 12 are spaced apart and closely arranged along the second direction.

[0029] According to some embodiments of the present invention, the diversion inlet 31 and / or diversion outlet 32 ​​are both configured as a plurality of such inlets spaced apart along a second direction. In this embodiment, as... Figure 4 As shown, by setting multiple diversion inlets 31 and diversion outlets 32, the uniformity of the cooling fluid flow can be further improved. Furthermore, the sum of the flow areas of the multiple diversion inlets 31 is equal to the sum of the flow areas of the multiple diversion outlets 32, and the number of diversion inlets 31 and diversion outlets 32 can be matched and set according to the size of chip 1.

[0030] According to some embodiments of the present invention, portions of the fourth flow channel 24 are disposed on both sides of the third flow channel 23 and are directly opposite the diversion outlet 32. In this embodiment, as... Figure 3 As shown, the fourth flow channel 24 is partially located on both sides of the third flow channel 23, matching the arrangement of the second flow channel 34. This achieves a correspondence between the first flow channel 33, the diversion inlet 31, and the third flow channel 23, and a correspondence between the second flow channel 34, the diversion outlet 32, and the fourth flow channel 24. This allows the cooling medium to flow in from the middle of the microchannel 12 and out from both ends, optimizing the flow path of the cooling medium and improving the heat dissipation effect and efficiency.

[0031] According to some embodiments of the present invention, a portion of the fourth flow channel 24 is disposed outside the end of the third flow channel 23 and communicates with the cooling medium outlet 22; the cooling medium outlet 22 is disposed directly opposite the end of the third flow channel 23. In this embodiment, the cooling medium enters the portion of the fourth flow channel 24 located on both sides of the third flow channel 23 through the two second flow channels 34 via the diversion outlet 32, and converges in the portion of the fourth flow channel 24 disposed outside the end of the third flow channel 23, and then flows out through the cooling medium outlet 22. Figure 2 , 3As shown, a portion of the fourth flow channel 24 is located on the outer side of the end of the third flow channel 23 and connects to the cooling medium outlet 22. This arrangement allows for communication between one cooling medium outlet 22 and two second flow channels 34. Simultaneously, the cooling medium outlet 22 is positioned directly opposite the end of the third flow channel 23, ensuring that the portions of the fourth flow channel 24 located on either side of the third flow channel 23 are in the same relative position as the cooling medium outlet 22, possessing equal flow path lengths. This improves the uniformity and stability of the cooling medium flow, thereby enhancing heat dissipation uniformity.

[0032] In the above embodiments, the present invention makes the temperature distribution of chip 1 more uniform when it is working by rationally arranging the flow direction of the working fluid and adopting a symmetrical outflow method.

[0033] According to some embodiments of the present invention, the orifice diameter of the cooling medium inlet 21 gradually decreases along the cooling medium inflow direction, while the orifice diameter of the cooling medium outlet 22 gradually increases along the cooling medium outflow direction. In this embodiment, the orifice diameters of the cooling medium inlet 21 and the cooling medium outlet 22 gradually change with the flow direction. The size of the cooling medium inlet 21 and the cooling medium outlet 22 can be changed by altering the height of the first distributor 2, adapting to different operating conditions and improving the flexibility of heat dissipation.

[0034] Furthermore, in some embodiments, the first distributor 2 has a trapezoidal cross-section along the second direction to accommodate the aperture changes of the cooling medium inlet 21 and the cooling medium outlet 22.

[0035] According to some embodiments of the present invention, the first splitter 2 is constructed with a symmetrical structure, and the axis of symmetry of the first splitter 2 extends along a second direction; the second splitter 3 is constructed with a symmetrical structure, and the axis of symmetry of the second splitter 3 extends along a second direction. In this embodiment, the first splitter 2 and the second splitter 3 are constructed with a symmetrical structure, and the axis of symmetry is perpendicular to the extension direction of the microchannel 12. This arrangement allows the flow path of the cooling working fluid to match the heat distribution of the chip 1, achieving symmetrical flow from the active region to both sides, improving the uniformity of heat dissipation, effectively reducing the junction temperature of the chip 1, and improving heat dissipation performance.

[0036] According to some embodiments of the present invention, the chip 1 and the heat sink 4 are connected by flip-chip bonding. In this embodiment, the flip-chip bonding of the chip 1 and the heat sink 4 can shorten the heat transfer path, allowing the heat from the active area of ​​the chip 1 to be quickly transferred downwards through the heat sink 4, thus achieving efficient heat dissipation.

[0037] According to some embodiments of the present invention, the heat sink 4 includes a substrate 41 and a metal layer 42, the metal layer 42 being disposed on both sides of the substrate 41, wherein one side of the metal layer 42 is connected to the chip 1. In this embodiment, as... Figure 7As shown, the heat sink 4 is constructed as a combination of a substrate 41 and a metal layer 42, which can balance high thermal conductivity, low cost, and lightweight, thereby improving the applicability and performance of the heat sink 4. In some embodiments, the substrate 41 is an AlN (aluminum nitride) substrate, which is lightweight, high-strength, and low-cost, while also having good thermal conductivity; the metal layer 42 is a copper layer, which has excellent thermal conductivity and good temperature uniformity; the copper layer is disposed at the junction with the chip 1 and at the external heat dissipation points, i.e., locations requiring high thermal conductivity, ensuring efficient heat absorption and dissipation, with aluminum nitride used in the middle for support and supplementary heat conduction, forming an efficient heat conduction path.

[0038] Furthermore, in some embodiments, the heat sink 4 uses AuSn (gold tin) as the solder layer 43 to achieve flip-chip bonding with the GaN laser chip 1.

[0039] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0040] In the description of this invention, "first feature" and "second feature" may include one or more of the features.

[0041] In the description of this invention, "a plurality of" means two or more.

[0042] In the description of this invention, the first feature being "above" or "below" the second feature may include the first and second features being in direct contact, or it may include the first and second features not being in direct contact but being in contact through another feature between them.

[0043] In the description of this invention, the terms "above," "over," and "on top" for the first feature and the second feature include the first feature being directly above or diagonally above the second feature, or simply indicating that the first feature is at a higher horizontal level than the second feature.

[0044] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0045] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A GaN blue laser, characterized by, The chip comprises a substrate, one side of the substrate is formed with a plurality of micro-channels by etching, each of the micro-channels is arranged along a first direction; The shunt assembly is arranged on the side of the substrate where the micro-channels are formed and is connected with the substrate; the side of the shunt assembly away from the substrate is formed with a cooling working medium inlet and a cooling working medium outlet, the side of the shunt assembly connected with the substrate is formed with a first flow channel and a second flow channel arranged along a second direction; the first flow channel is communicated with the cooling working medium inlet, the second flow channel is communicated with the cooling working medium outlet, and each of the micro-channels is communicated with the first flow channel and the second flow channel; The heat sink is arranged on the side of the chip away from the substrate and is connected with the chip. The shunt assembly comprises:

2. The GaN blue laser of claim 1, wherein, A first shunt and a second shunt, the second shunt is connected with the substrate, and the first shunt is connected with the second shunt; wherein, The side of the first shunt away from the second shunt is formed with the cooling working medium inlet and the cooling working medium outlet; the side of the first shunt connected with the second shunt is formed with a third flow channel and a fourth flow channel; the third flow channel is communicated with the cooling working medium inlet, and the fourth flow channel is communicated with the cooling working medium outlet; The side of the second shunt connected with the substrate is formed with the first flow channel and the second flow channel; the side of the second shunt connected with the first shunt is formed with a shunt inlet and a shunt outlet, the shunt inlet is communicated with the first flow channel and the third flow channel, and the shunt outlet is communicated with the second flow channel and the fourth flow channel. The second flow channel is configured as two, which are arranged on both sides of the first flow channel respectively.

3. The GaN blue laser of claim 2, wherein, The shunt inlet and / or the shunt outlet is configured as a plurality of which are arranged at intervals along the second direction.

4. The GaN blue laser of claim 3, wherein, Part of the fourth flow channel is arranged on both sides of the third flow channel and faces a plurality of the shunt outlets.

5. The GaN blue laser of claim 4, wherein, Part of the fourth flow channel is arranged outside the end of the third flow channel and is communicated with the cooling working medium outlet; the cooling working medium outlet is arranged opposite to the end of the third flow channel.

6. The GaN blue laser of claim 5, wherein, The aperture of the cooling working medium inlet gradually decreases along the direction of the cooling working medium flowing in, and the aperture of the cooling working medium outlet gradually increases along the direction of the cooling working medium flowing out.

7. The GaN blue laser of claim 2, wherein, The first shunt is configured as a symmetrical structure, and the symmetry axis of the first shunt extends along the second direction; the second shunt is configured as a symmetrical structure, and the symmetry axis of the second shunt extends along the second direction.

8. The GaN blue laser of claim 3, wherein, The chip and the heat sink are connected by flip-chip bonding.

9. The GaN blue laser of claim 1, wherein, The heat sink comprises a substrate and a metal layer, the metal layer is arranged on both sides of the substrate, and one side of the metal layer is connected with the chip.

10. The GaN blue laser of claim 1, wherein, ​

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