Two-phase liquid cooling device and method based on diamond copper micro-channel and piezoelectric atomization

Abstract

The invention discloses a two-phase liquid cooling device and method based on a diamond copper micro-channel and piezoelectric atomization, the device comprises a chip assembly, a phase change cavity assembly, a heat conduction assembly and a jet flow assembly, the chip assembly comprises a high-power chip and a thermal interface material layer; the phase change cavity assembly comprises a heat dissipation substrate and a sealing cover, and a phase change cavity is defined by the heat dissipation substrate and the sealing cover. The heat conduction assembly comprises a diamond copper composite material compact layer and a diamond copper composite material porous layer. The jet flow assembly comprises a nozzle, a liquid storage tank, a piezoelectric pump, a piezoelectric drive and controller and a radiator. The heat conductivity coefficient, boiling stability, device integration and device compatibility of the two-phase liquid cooling device are improved.

Description

Technical Field

[0001] This invention relates to the field of chip technology, and in particular to a two-phase liquid cooling device and method based on diamond copper microchannels and piezoelectric atomization. Background Technology

[0002] With the rapid development of large-scale artificial intelligence models, their training and inference have placed unprecedented demands on computing power, driving a sharp increase in power density. This has resulted in a continuous increase in the heat flux density of high-performance, highly integrated chips, with the maximum heat flux density exceeding 100 W / cm². 2 This presents significant challenges to thermal management, including heat dissipation. Statistics show that approximately 55% of electronic product failures are caused by thermal management issues. Furthermore, the high integration of chip packaging results in extremely uneven heat generation. Traditional air-cooling technologies are insufficient to effectively control localized hotspot temperatures, necessitating cooling solutions with superior heat dissipation performance.

[0003] In recent years, liquid cooling technology with higher heat transfer performance has received widespread attention and has been widely applied in industries such as servers. Liquid cooling technology is mainly divided into passive and active types. Passive two-phase liquid cooling mainly uses capillary evaporation and liquid film boiling in a vapor chamber, which has advantages such as high heat transfer efficiency and no need for external power. However, due to the lack of external drive such as pumps, the applicable heat flux density is relatively low. Active liquid cooling includes jet cooling, spray cooling, and microchannel cooling, which have higher heat transfer performance. However, the heat transfer performance of active liquid cooling technology is closely related to parameters such as the specific heat capacity, latent heat, and surface tension of the liquid working fluid. Currently, the heat flux density that can be achieved is 100-300 W / cm³. 2 Heat transfer coefficient 10-70 kW / (cm²) 2 The heat transfer performance of active liquid cooling technology, with a temperature (•K), is far lower than that of liquid media. Improving the heat transfer performance of active liquid cooling technology has become a key bottleneck in the development of thermal management technology for electronic devices. Single-phase active liquid cooling, represented by cold plates, removes heat from the chip through forced convection sensible heat transfer. It improves heat transfer characteristics by adding microchannels, fins, etc., to increase the heat transfer area and create turbulence. Due to its simple structure, ease of implementation, and low cost, it is currently a commonly used method. This method mainly uses heat exchange for heat transfer, and is greatly affected by the flow rate, specific heat capacity, and temperature difference of the liquid working fluid, resulting in relatively limited cooling performance. Two-phase active liquid cooling technology utilizes the latent heat of phase change for heat transfer, achieving high heat transfer performance with relatively small subcooling and flow rates. Common methods include flow boiling and jet boiling. However, flow boiling is prone to unstable boiling, causing serious problems such as heat exchange performance oscillation and equipment thermal fatigue. High-speed jet boiling can handle the heat dissipation of chips with extremely high heat flux density, but it relies on high-pressure gas and other methods to achieve high-speed atomization jet of liquid working fluid. The system is complex, consumes a lot of power, is difficult to miniaturize, and is hard to meet the needs of applications such as AI computing servers with high-power chips as the application scenario.

[0004] Improving the thermal conductivity, boiling stability, device integration, and device compatibility of two-phase liquid cooling devices are technical problems that urgently need to be solved in this field. Summary of the Invention

[0005] Therefore, the present invention provides a two-phase liquid cooling device and method based on diamond copper microchannels and piezoelectric atomization, which improves the thermal conductivity, boiling stability, device integration and device compatibility of the two-phase liquid cooling device.

[0006] To solve the above-mentioned technical problems, the present invention provides a two-phase liquid cooling device based on diamond copper microchannels and piezoelectric atomization, comprising: A chip assembly includes a high-power chip and a thermal interface material layer, wherein the thermal interface material layer is stacked on one side of the high-power chip along the thickness direction; A phase change cavity assembly includes a heat dissipation substrate and a cover. The heat dissipation substrate is stacked and connected to the side of the thermal interface material layer opposite to the high-power chip. The cover is connected to the side of the heat dissipation substrate opposite to the thermal interface material layer. The cover and the heat dissipation substrate enclose a phase change cavity. A heat-conducting component, disposed within the phase change cavity, includes a dense layer of diamond-copper composite material and a porous layer of diamond-copper composite material. The dense layer of diamond-copper composite material is stacked on the side of the heat dissipation substrate away from the thermal interface material layer, and the porous layer of diamond-copper composite material is stacked on the side of the dense layer of diamond-copper composite material away from the heat dissipation substrate. The jet assembly includes a nozzle, a reservoir, a piezoelectric pump, a piezoelectric actuator and controller, and a radiator. The nozzle is mounted on the cover and is used to spray liquid coolant into the phase change chamber. The reservoir stores the liquid coolant. The piezoelectric pump is connected between the nozzle and the reservoir and is used to drive the coolant in the reservoir to flow to the nozzle. The piezoelectric actuator and controller are connected to the piezoelectric pump and are used to supply power to the piezoelectric pump. The radiator is connected to the phase change chamber and is used to receive gaseous coolant from the phase change chamber and transfer heat to the surrounding environment.

[0007] Optionally, the density of the diamond-copper composite material dense layer is not less than 90%, and the thermal conductivity is not less than 500 W / (cm2•K).

[0008] Optionally, the density of the porous layer of the diamond-copper composite material is 30%-80%, and the diameter of the micropores in the porous layer of the diamond-copper composite material is 0.03-1.0 mm, and the depth is 0.2-3.0 mm.

[0009] Optionally, both the dense layer and the porous layer of the diamond-copper composite material are prepared by hot pressing and sintering of diamond particles and copper powder, current-assisted sintering, or pressure infiltration processes.

[0010] Optionally, the thermal interface material layer is thermally conductive silicone grease or silicone, with a thickness of 3-20 μm.

[0011] Optionally, the heat dissipation substrate is a copper substrate with a thickness of no more than 200 μm.

[0012] Optionally, the cover has a through hole, the nozzle is installed at the end of the through hole facing the phase change cavity, the liquid storage tank is connected to the side wall of the through hole, the piezoelectric pump includes a spring plate and a piezoelectric ceramic, the spring plate is located at the end of the through hole away from the phase change cavity, the piezoelectric ceramic is connected to the spring plate, and the piezoelectric drive and controller are connected to the piezoelectric ceramic.

[0013] Optionally, the cooling medium is a mixture of water, propylene glycol and water, refrigerant R515B, or fluorinated liquid.

[0014] Optionally, the radiator is connected to the liquid storage tank, and the liquid cooling medium in the radiator flows back into the liquid storage tank.

[0015] This invention also provides a two-phase liquid cooling method based on diamond copper microfluidics and piezoelectric atomization. When the two-phase liquid cooling device is working, the liquid cooling medium in the storage tank is driven to the nozzle by the piezoelectric pump. The liquid cooling medium is further sprayed into the phase change cavity through the nozzle. The heat generated by the high-power chip is transferred to the heat dissipation substrate through the thermal interface material. The heat is further transferred to the dense layer and porous layer of the diamond copper composite material through the heat dissipation substrate, and then to the cooling medium in the phase change cavity. Part or all of the cooling medium changes from liquid to gas, completing the phase change heat absorption. The partially or completely vaporized cooling medium flows to the heat sink. The heat sink transfers the heat carried by the vaporized cooling medium, and the cooling medium also changes from gas to liquid again.

[0016] Compared with the prior art, the above-mentioned technical solution of the present invention has the following advantages: The two-phase liquid cooling device and method based on diamond copper microchannel and piezoelectric atomization of the present invention combines microchannel phase change heat transfer and jet boiling heat transfer. The porous structure of the diamond copper is conducive to bubble nucleation, reducing the bubble size and avoiding large-sized, high-thermal-resistance bubbles from isolating the diamond copper from the cooling medium droplets, forming unstable boiling phase change heat absorption, and reducing heat transfer efficiency. The cooling medium droplets are small in size and absorb heat quickly, which is conducive to faster vaporization and improves heat transfer efficiency. At the same time, the piezoelectric atomization jet is very fast, and multiple piezoelectric atomization jet devices can be arranged to quickly replenish the consumption of liquid cooling medium, ensuring that the heat transfer process is efficient, continuous and stable. This invention fully utilizes the advantages of diamond copper, such as its high thermal conductivity reducing thermal resistance, its porous structure facilitating stable boiling vaporization, and its piezoelectric atomization jet technology, which is suitable for high-viscosity liquid working fluids, has good atomization effect, small droplet size, and simple structure, small size, and is easy to integrate. It makes up for the shortcomings of existing two-phase liquid cooling technology in terms of thermal resistance, boiling stability, large device size, poor integration and compatibility, and meets the urgent needs of high heat flux density chip thermal management. Attached Figure Description

[0017] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0018] Figure 1 This is a schematic diagram of the two-phase liquid cooling device based on diamond copper microchannels and piezoelectric atomization disclosed in this invention.

[0019] Explanation of reference numerals in the accompanying drawings: 11. High-power chip; 12. Thermal interface material layer; 21. Heat dissipation substrate; 22. Cap; 23. Phase change cavity; 31. Dense layer of diamond-copper composite material; 32. Porous layer of diamond-copper composite material; 41. Nozzle; 42. Liquid reservoir; 43. Piezoelectric pump; 431. Spring plate; 432. Piezoelectric ceramic; 44. Piezoelectric drive and controller; 45. Heat sink. Detailed Implementation

[0020] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0021] See Figure 1 As shown, this invention discloses an embodiment of a two-phase liquid cooling device based on diamond copper microchannels and piezoelectric atomization.

[0022] Two-phase liquid cooling devices based on diamond copper microchannels and piezoelectric atomization include: The chip assembly includes a high-power chip 11 and a thermal interface material layer 12, wherein the thermal interface material layer 12 is stacked on one side of the high-power chip 11 along the thickness direction. The phase change cavity assembly includes a heat dissipation substrate 21 and a cover 22. The heat dissipation substrate 21 is stacked and connected to the side of the thermal interface material layer 12 away from the high-power chip 11. The cover 22 is connected to the side of the heat dissipation substrate 21 away from the thermal interface material layer 12. The cover 22 and the heat dissipation substrate 21 enclose a phase change cavity 23. A heat-conducting component is disposed in the phase change cavity 23, including a dense diamond copper composite material layer 31 and a porous diamond copper composite material layer 32. The dense diamond copper composite material layer 31 is stacked on the side of the heat dissipation substrate 21 away from the thermal interface material layer 12, and the porous diamond copper composite material layer 32 is stacked on the side of the dense diamond copper composite material layer 31 away from the heat dissipation substrate 21. The jet assembly includes a nozzle 41, a liquid reservoir 42, a piezoelectric pump 43, a piezoelectric drive and controller 44, and a radiator 45. The nozzle 41 is mounted on the cover 22 and is used to spray liquid coolant into the phase change chamber 23. The liquid reservoir 42 is used to store the liquid coolant. The piezoelectric pump 43 is connected between the nozzle 41 and the liquid reservoir 42 and is used to drive the coolant in the liquid reservoir 42 to flow to the nozzle 41. The piezoelectric drive and controller 44 is connected to the piezoelectric pump 43 and is used to supply power to the piezoelectric pump 43. The radiator 45 is connected to the phase change chamber 23 and is used to receive the gaseous coolant from the phase change chamber 23 and transfer heat to the surrounding environment.

[0023] Specifically, the high-power chip 11 is the core component to be cooled and is the object of heat dissipation in this device; the thermal interface material layer 12 is used to eliminate the contact thermal resistance between the high-power chip 11 and the heat dissipation substrate 21, so as to achieve efficient heat transfer.

[0024] The heat dissipation substrate 21 serves as the core load-bearing and thermally conductive substrate for transferring heat from the high-power chip 11 to the phase change cavity 23. The cover 22 is sealed to the side of the heat dissipation substrate 21 away from the thermal interface material layer 12, and the two together form a closed phase change cavity 23, providing a closed space for the atomization and phase change of the cooling working fluid, ensuring the high efficiency of phase change heat transfer and the closed circulation of the working fluid. In this embodiment, grooves are formed on the opposing surfaces of the heat dissipation substrate 21 and the cover 22. The thermally conductive components are embedded in the grooves of the heat dissipation substrate 21, and the grooves of the cover 22 mainly serve to form the phase change cavity 23.

[0025] The dense layer 31 of diamond-copper composite material relies on the high thermal conductivity of diamond-copper composite material to quickly conduct the heat transferred from the heat dissipation substrate 21 to the porous layer 32 of diamond-copper composite material. At the same time, the dense layer structure prevents the cooling working fluid from penetrating into the heat dissipation substrate 21, ensuring thermal conductivity efficiency. The porous structure of the porous layer 32 of diamond-copper composite material forms a microchannel network, which is more conducive to the efficient and stable boiling heat exchange of the cooling working fluid droplets. Moreover, it has good compatibility with the dense layer of diamond-copper composite material and can be fabricated in an integrated manner.

[0026] The nozzle 41 faces the interior of the phase change cavity 23, atomizing the liquid coolant and spraying it onto the surface of the porous diamond-copper composite material layer 32 within the phase change cavity 23, achieving precise and efficient contact between the coolant and the highly thermally conductive substrate. The storage tank 42 stores a sufficient amount of room-temperature liquid coolant, providing continuous replenishment for the entire heat dissipation device. The piezoelectric pump 43 provides power for the delivery of the coolant, driving the liquid coolant in the storage tank 42 to flow towards the nozzle 41 at a preset pressure and flow rate, ensuring stable atomization effect of the nozzle 41. The piezoelectric atomizing jet is not only simple in structure, integrated, and compatible, but also suitable for coolants of different viscosities, with good atomization effect, high efficiency, and fast jet speed, facilitating integration with the heat dissipation structure. The piezoelectric drive and controller 44 provides controllable electric drive power to the piezoelectric pump 43, enabling adjustment of the operating parameters of the piezoelectric pump 43. A liquid outlet hole is provided on the side of the cover 22 as an outlet channel for the gas-liquid mixed cooling medium. This channel is connected to the radiator 45 through a pipe. The radiator 45 receives the gaseous cooling medium formed by the vaporization of the cooling medium after absorbing heat in the phase change chamber 23. The heat of the gaseous cooling medium is transferred to the surrounding environment through the heat exchange structure of the radiator 45, thereby achieving the cooling and condensation of the gaseous cooling medium.

[0027] The following describes the working method of the two-phase liquid cooling device based on diamond copper microfluidic channels and piezoelectric atomization. When the two-phase liquid cooling device is working, the piezoelectric pump 43 drives the liquid cooling medium in the storage tank 42 to the nozzle 41. The liquid cooling medium is further sprayed into the phase change cavity 23 through the nozzle 41. The heat generated by the high-power chip 11 is transferred to the heat dissipation substrate 21 through the thermal interface material layer 12. The heat is further transferred to the dense layer 31 and the porous layer 32 of the diamond copper composite material through the heat dissipation substrate 21, and then to the cooling medium in the phase change cavity 23. Part or all of the cooling medium changes from liquid to gas, completing the phase change heat absorption. The partially or completely vaporized cooling medium flows to the radiator 45. The radiator 45 transfers the heat carried by the vaporized cooling medium, and the cooling medium also changes from gas to liquid again.

[0028] The above technical solution combines microchannel phase change heat transfer and jet boiling heat transfer. The porous structure of the diamond copper facilitates bubble nucleation, reduces bubble size, and prevents large, thermally resistant bubbles from isolating the diamond copper from the cooling fluid droplets, thus avoiding unstable boiling phase change heat absorption and reduced heat transfer efficiency. The small size and rapid heat absorption of the cooling fluid droplets facilitate faster vaporization and improve heat transfer efficiency. Simultaneously, the piezoelectric atomizing jet is very fast, and multiple piezoelectric atomizing jet devices can be arranged to quickly replenish the consumed liquid cooling fluid, ensuring the efficient, continuous, and stable operation of the heat transfer process. This invention fully utilizes the advantages of diamond copper's high thermal conductivity (reducing thermal resistance), porous structure (facilitating stable boiling vaporization), and piezoelectric atomizing jet technology (suitable for high-viscosity liquids, good atomization effect, small droplet size, simple structure, and easy integration). It overcomes the shortcomings of existing two-phase liquid cooling technologies in terms of thermal resistance, boiling stability, large device size, poor integration, and compatibility, meeting the urgent needs of high heat flux density chip thermal management.

[0029] In this embodiment, the density of the diamond-copper composite material dense layer 31 is not less than 90%, and the thermal conductivity is not less than 500 W / (cm2•K).

[0030] Specifically, density is a core indicator describing the compactness of multiphase composite materials (such as the diamond-copper composite material in this case) or powder metallurgy formed materials. Also known as volumetric density, it is a key parameter measuring the proportion of internal defects such as pores and gaps. The density of the dense layer 31 of the diamond-copper composite material is not less than 90%, meaning that the effective solid volume (diamond + copper matrix) within this layer accounts for 90% or more of the overall geometric volume, and the internal porosity is ≤10%. Since the heat conduction efficiency in solid media is much higher than in air (the medium within pores) (air's thermal conductivity is only about 0.023 W / (m·K), far lower than that of copper and diamond), high density means fewer pores. During heat transfer, air pores will not form a "thermal resistance barrier," ensuring that the heat from the heat dissipation substrate 21 can be quickly and losslessly conducted to the porous layer 32 of the diamond-copper composite material, meeting the performance requirement of a high thermal conductivity of ≥500 W / (m·K).

[0031] Through the above technical solution, the dense layer of diamond-copper composite material can quickly transfer the heat of the heat dissipation substrate to the porous layer of diamond composite material.

[0032] In this embodiment, the density of the porous layer 32 of the diamond-copper composite material is 30%-80%, and the diameter of the micropores in the porous layer 32 of the diamond-copper composite material is 0.03-1.0 mm, and the depth is 0.2-3.0 mm.

[0033] Specifically, the density of the porous layer 32 of the diamond-copper composite material is 30%-80%. If it is below 30%, the structural strength of the porous layer 32 of the diamond-copper composite material is insufficient, and it is prone to deformation and collapse under high temperature conditions. If it is above 80%, the proportion of micropores is too small, the contact area of ​​the cooling working fluid is greatly reduced, and the phase change heat transfer efficiency is significantly reduced. 30%-80% is the optimal balance range between structural strength and heat transfer efficiency. The density of the porous layer 32 of the diamond-copper composite material can be 30%, 40%, 50%, 60%, 70% or 80%.

[0034] The micropore diameter is 0.03-1.0 mm. If it is less than 0.03 mm, the micropore is easily blocked by tiny impurities in the atomized droplets, leading to microchannel failure. If it is greater than 1.0 mm, the atomized droplets can easily flow through the micropore quickly, making it impossible to achieve sufficient contact and phase change. 0.03-1.0 mm is the optimal range for atomized droplet diffusion and micropore anti-clogging. The micropore diameter can be 0.03 mm, 0.05 mm, 0.07 mm, 0.09 mm, 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, or 1 mm.

[0035] The micropore depth should be 0.2-3.0 mm. If the depth is less than 0.2 mm, the contact time between the droplet and the high-temperature surface will be too short, resulting in insufficient phase change. If the depth is greater than 3.0 mm, the liquid working fluid may remain at the bottom of the micropore, unable to vaporize and drain in time, affecting subsequent heat exchange efficiency. 0.2-3.0 mm is the optimal range for contact time and working fluid drainage. Micropore depths can be 0.2 mm, 0.4 mm, 0.6 mm, 0.8 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, or 3.0 mm.

[0036] Through the above technical solutions, the porous layer of diamond composite material can achieve full contact and efficient phase change of the cooling working fluid.

[0037] In this embodiment, both the dense layer 31 and the porous layer 32 of the diamond-copper composite material are prepared by hot pressing and sintering of diamond particles and copper powder, current-assisted sintering, or pressure infiltration processes.

[0038] Specifically, hot pressing sintering, current-assisted sintering, and pressure infiltration processes can all achieve a tight bond between diamond particles and the copper matrix, effectively solving the interfacial wettability problem between diamond and copper and ensuring the high thermal conductivity of the composite material. At the same time, all three processes can achieve precise control of density by adjusting the sintering pressure, temperature, and holding time (hot pressing / current-assisted sintering) or the copper infiltration pressure and temperature (pressure infiltration), meeting the differentiated density requirements of the dense layer and the porous layer of the diamond-copper composite material.

[0039] The above technical solutions can be used to prepare dense layers and porous layers of diamond-copper composite materials.

[0040] In this embodiment, the thermal interface material layer 12 is thermally conductive silicone grease or silicone with a thickness of 3-20 μm.

[0041] Specifically, thermal grease / silicone is selected because both have excellent thermal conductivity and good deformation adhesion, which can fully fill the microscopic gaps between the chip and the heat dissipation substrate, making them efficient interface materials in the field of electronic heat dissipation. The thickness is limited to 3-20μm, because if it is less than 3μm, the contact thermal resistance will not be completely eliminated due to uneven coating, and if it is greater than 20μm, the overall thermal conductivity will be reduced due to the thermal resistance of the material itself. 3-20μm is the optimal balance range between eliminating contact thermal resistance and controlling its own thermal conductivity.

[0042] Through the above technical solutions, the thermal interface material has good thermal conductivity and low thermal resistance.

[0043] In this embodiment, the heat dissipation substrate 21 is a copper substrate with a thickness of no more than 200 μm.

[0044] Specifically, copper has a thermal conductivity of approximately 401 W / (m·K), which is much higher than that of other commonly used substrate materials such as aluminum. Combined with a thin design of ≤200μm, it can significantly reduce the thermal resistance of the heat dissipation substrate itself. It can quickly receive the chip heat transferred from the thermal interface material layer and efficiently conduct it to the diamond copper dense layer, avoiding heat accumulation at the substrate. This meets the core requirement of "low-resistance heat dissipation throughout the entire path" of the device and helps to achieve rapid heat transfer with high heat flux density.

[0045] The above technical solution results in a heat dissipation substrate with high thermal conductivity and low thermal resistance.

[0046] In this embodiment, the cover 22 is provided with a liquid inlet hole, the nozzle 41 is installed at the end of the liquid inlet hole facing the phase change cavity 23, the liquid storage tank 42 is connected to the side wall of the liquid inlet hole, the piezoelectric pump 43 includes a spring plate 431 and a piezoelectric ceramic 432, the spring plate 431 is provided at the end of the liquid inlet hole away from the phase change cavity 23, the piezoelectric ceramic 432 is connected to the spring plate 431, and the piezoelectric drive and controller 44 is connected to the piezoelectric ceramic 432.

[0047] Specifically, when the piezoelectric drive and controller 44 is activated, the piezoelectric ceramic 432 undergoes periodic elongation and compression alternating deformation, which drives the spring plate 431 to elongate and compress periodically. Since the periphery of the spring plate 431 is fixed to the cover 22, it undergoes periodic deformation of upward protrusion and downward depression, thereby pushing the cooling medium to flow towards the nozzle 41. Since the piezoelectric drive and controller 44 outputs a very high pulse voltage frequency, up to 30kHz, the liquid cooling medium is atomized under high-speed impact to form tiny droplets with a size of only micrometers, and is sprayed into the heat conduction component through the nozzle 41.

[0048] The above technical solution achieves the atomization of liquid cooling working fluid.

[0049] In this embodiment, the cooling medium is a mixture of water, propylene glycol and water, refrigerant R515B, or fluorinated liquid.

[0050] Specifically, water, a mixture of propylene glycol and water, refrigerant R515B, or fluorinated liquid are selected as the cooling medium. Each medium is suitable for different heat dissipation conditions and operating environments. Water has excellent thermal conductivity and latent heat of phase change, and is inexpensive. The mixture of propylene glycol and water is resistant to low temperatures and prevents freezing. Refrigerant R515B and fluorinated liquid have high phase change efficiency and are suitable for efficient heat exchange in closed chambers, which can meet the heat dissipation requirements of high-power chips in different application scenarios.

[0051] By using the above technical solutions, a matching cooling medium can be selected as needed to achieve efficient heat dissipation for high-power chips.

[0052] In this embodiment, the radiator 45 is connected to the liquid storage tank 42, and the liquid cooling medium in the radiator 45 flows back into the liquid storage tank 42.

[0053] Specifically, the radiator 45 is connected to the liquid storage tank 42 via pipes. The radiator 45 transfers the heat carried by the vaporized cooling medium through thermal radiation and convection, while the cooling medium changes from a gaseous state back to a liquid state. At this point, it can be returned to the liquid storage tank 42 for reuse.

[0054] The above technical solution enables the recycling of the cooling medium.

[0055] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A two-phase liquid cooling device based on diamond copper microchannels and piezoelectric atomization, characterized in that, include: A chip assembly includes a high-power chip and a thermal interface material layer, wherein the thermal interface material layer is stacked on one side of the high-power chip along the thickness direction; A phase change cavity assembly includes a heat dissipation substrate and a cover. The heat dissipation substrate is stacked and connected to the side of the thermal interface material layer opposite to the high-power chip. The cover is connected to the side of the heat dissipation substrate opposite to the thermal interface material layer. The cover and the heat dissipation substrate enclose a phase change cavity. A heat-conducting component, disposed within the phase change cavity, includes a dense layer of diamond-copper composite material and a porous layer of diamond-copper composite material. The dense layer of diamond-copper composite material is stacked on the side of the heat dissipation substrate away from the thermal interface material layer, and the porous layer of diamond-copper composite material is stacked on the side of the dense layer of diamond-copper composite material away from the heat dissipation substrate. The jet assembly includes a nozzle, a reservoir, a piezoelectric pump, a piezoelectric actuator and controller, and a radiator. The nozzle is mounted on the cover and is used to spray liquid coolant into the phase change chamber. The reservoir stores the liquid coolant. The piezoelectric pump is connected between the nozzle and the reservoir and is used to drive the coolant in the reservoir to flow to the nozzle. The piezoelectric actuator and controller are connected to the piezoelectric pump and are used to supply power to the piezoelectric pump. The radiator is connected to the phase change chamber and is used to receive gaseous coolant from the phase change chamber and transfer heat to the surrounding environment.

2. The two-phase liquid cooling device according to claim 1, characterized in that, The density of the diamond-copper composite material dense layer is not less than 90%, and the thermal conductivity is not less than 500 W / (cm2•K).

3. The two-phase liquid cooling device according to claim 1, characterized in that, The density of the porous layer of the diamond-copper composite material is 30%-80%, and the diameter of the micropores in the porous layer of the diamond-copper composite material is 0.03-1.0 mm, and the depth is 0.2-3.0 mm.

4. The two-phase liquid cooling device according to claim 1, characterized in that, Both the dense layer and the porous layer of the diamond-copper composite material are prepared by hot pressing and sintering of diamond particles and copper powder, current-assisted sintering, or pressure infiltration processes.

5. The two-phase liquid cooling device according to claim 1, characterized in that, The thermal interface material layer is thermally conductive silicone grease or silicone, with a thickness of 3-20 μm.

6. The two-phase liquid cooling device according to claim 1, characterized in that, The heat dissipation substrate is a copper substrate with a thickness of no more than 200 μm.

7. The two-phase liquid cooling device according to claim 1, characterized in that, The cover has a through hole, the nozzle is installed at the end of the through hole facing the phase change cavity, the liquid storage tank is connected to the side wall of the through hole, the piezoelectric pump includes a spring plate and a piezoelectric ceramic, the spring plate is located at the end of the through hole away from the phase change cavity, the piezoelectric ceramic is connected to the spring plate, and the piezoelectric drive and controller are connected to the piezoelectric ceramic.

8. The two-phase liquid cooling device according to claim 1, characterized in that, The cooling medium is a mixture of water, propylene glycol and water, refrigerant R515B, or fluorinated liquid.

9. The two-phase liquid cooling device according to claim 1, characterized in that, The radiator is connected to the liquid storage tank, and the liquid cooling medium in the radiator flows back to the liquid storage tank.

10. A two-phase liquid cooling method based on diamond copper microchannels and piezoelectric atomization, characterized in that, When the two-phase liquid cooling device according to any one of claims 1 to 9 is working, the liquid cooling medium in the storage tank is driven to the nozzle by the piezoelectric pump. The liquid cooling medium is further sprayed into the phase change cavity through the nozzle. The heat generated by the high-power chip is transferred to the heat dissipation substrate through the thermal interface material. The heat is further transferred to the dense layer and porous layer of the diamond copper composite material through the heat dissipation substrate, and then to the cooling medium in the phase change cavity. Part or all of the cooling medium changes from liquid to gas, completing the phase change heat absorption. The partially or completely vaporized cooling medium flows to the heat sink. The heat sink transfers the heat carried by the vaporized cooling medium, and the cooling medium also changes from gas to liquid again.

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