Light aluminum-based uniform-temperature plate structure with silk screen groove composite structure and preparation method of light aluminum-based uniform-temperature plate structure

Abstract

The invention provides a silk screen groove composite structure light aluminum-based uniform temperature plate structure and a preparation method thereof, and belongs to the field of light aluminum-based uniform temperature plate two-phase radiator manufacturing, the silk screen groove composite structure light aluminum-based uniform temperature plate structure comprises an evaporation end bottom plate, a liquid injection pipe, a liquid injection port and a condensation end cover plate, the liquid injection port is formed in one side of the evaporation end bottom plate and connected with the liquid injection pipe, and the condensation end cover plate is connected with the liquid injection pipe. And the condensation end cover plate is arranged on the evaporation end bottom plate. The evaporation end bottom plate comprises a non-central area supporting column, radial micro-grooves, linear micro-grooves, a central area supporting column, a boss and a micro-nano wire mesh capillary core, the boss is arranged at the center of the evaporation end bottom plate, and the four linear micro-grooves are formed in the evaporation end bottom plate along the four edges of the boss; the evaporation end bottom plate is provided with a boss and four linear micro-grooves, the other positions of the evaporation end bottom plate except the boss and the four linear micro-grooves are provided with radial micro-grooves, a micro-nano wire mesh capillary core is arranged at the concave position of the boss, the top of the micro-nano wire mesh capillary core is uniformly provided with central area supporting columns, and the tops of the radial micro-grooves and the four linear micro-grooves are uniformly provided with non-central area supporting columns.

Description

Technical Field

[0001] This invention relates to the field of manufacturing lightweight aluminum-based vapor chamber two-phase heat sinks, and particularly to a lightweight aluminum-based vapor chamber structure with a wire mesh groove composite structure and its preparation method. Background Technology

[0002] As chip versions iterate and integration increases, heat flux also rises. Simultaneously, with the rapid development of communication equipment, quantum computing, optoelectronic computing, and aerospace, heat dissipation issues have become prominent. Research indicates that 55% of electronic component failures are due to thermal failure, and for every 2-degree Celsius increase in electronic component temperature, reliability decreases by 10%. Therefore, there is an urgent need for an efficient heat dissipation device to address the heat dissipation requirements of high-heat-flux chips.

[0003] In recent years, vapor chamber cooling devices derived from heat pipes have received widespread attention and solved most heat dissipation needs. The working principle of a vapor chamber is mainly based on the evaporation phase change of the internal working fluid. Heat is diffused throughout the vapor chamber via vapor, then condenses into liquid at the condensation surface and flows back to the evaporation end through an internal liquid return structure, continuously circulating. Currently, the most commonly used vapor chamber structure in engineering applications is a combination of copper-copper sintered capillary-ultrapure water. This structure has significant performance advantages due to the stronger liquid return driving force of the sintered capillary structure and the higher latent heat of vaporization of water. However, copper-based vapor chambers are relatively heavy, and there is an urgent need for lighter vapor chambers in fields such as portable communication devices, 5G base stations, and aerospace to reduce the weight of equipment. Aluminum is a metal with high thermal conductivity (234 W / m·K), and its mass for the same volume is only 3 / 10 that of copper, while its price for the same mass is only 1 / 10 that of copper. Therefore, aluminum-based vapor chambers have potential application value. However, the manufacturing process of the capillary structure inside the aluminum-based heat exchanger is demanding and expensive. In addition, the incompatibility between aluminum and water has always existed. Therefore, refrigerants, fluorinated liquids or organic solvents are often used as working fluids, which results in the relatively low maximum heat dissipation power of existing aluminum-based heat exchangers. Summary of the Invention

[0004] The purpose of this invention is to provide a lightweight aluminum-based vapor chamber structure with wire mesh groove composite structure and its preparation method, which is suitable for the thermal management of medium and high power chips. Compared with traditional copper-based vapor chambers, this invention reduces the weight of the equipment; compared with existing aluminum-based vapor chambers, it is easier to process and has a lower cost, while meeting the heat dissipation requirements of higher power.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A lightweight aluminum-based heat spreader structure with a wire mesh groove composite structure is characterized by comprising an evaporation end base plate, a liquid injection pipe, a liquid injection port, and a condensation end cover plate. The evaporation end base plate is provided with a liquid injection port on one side and serves as the site for evaporation phase change. The liquid injection port is connected to the liquid injection pipe. The condensation end cover plate is disposed on the evaporation end base plate and serves as the main site for liquid condensation.

[0006] The evaporator end base plate includes a non-central area support column, radial microgrooves, linear microgrooves, a central area support column, a boss, and a micro / nano mesh capillary core. A boss is provided at the center of the evaporator end base plate for contacting the heat source. Four linear microgrooves are provided along the four sides of the boss. Radial microgrooves are provided at the remaining positions of the evaporator end base plate except for the boss and the four linear microgrooves. A micro / nano mesh capillary core is provided in the concave part of the boss. A central area support column is uniformly provided on the top of the micro / nano mesh capillary core. Non-central area support columns are uniformly provided on the top of the radial microgrooves and the four linear microgrooves.

[0007] Furthermore, the micro / nano mesh capillary core is prepared by chemically etching or depositing micro / nano structures on the surface of multi-layer mesh capillary cores. The multi-layer mesh capillary core is prepared by stacking multiple mesh structures through hot pressing. The mesh structure is prepared by processing the mesh into a pre-designed shape using a femtosecond laser.

[0008] Furthermore, the height difference of the boss is 5mm to 15mm.

[0009] Furthermore, the fractal angle inside the radial microgrooves is 5° to 45°, there is a height difference between radial microgrooves at different positions, and there is a height difference between linear microgrooves at different positions. The closer the radial and linear microgrooves are to the center, the lower their height, and the height difference ΔH is 0.5mm to 3mm.

[0010] Furthermore, the radial microgrooves and linear microgrooves are U-shaped grooves, T-shaped grooves, or V-shaped grooves, and the characteristic dimensions of the radial microgrooves and linear microgrooves are a depth of 0.1 mm to 1 mm and a spacing between adjacent grooves of 0.1 mm to 1 mm.

[0011] Furthermore, the multilayer wire mesh capillary core is prepared by stacking 2 to 8 wire mesh structures.

[0012] A method for preparing a lightweight aluminum-based heat spreader structure with a wire mesh grooved composite structure, characterized by comprising the following steps: Step S1. Preparation of evaporation end base plate and condensation end cover plate: The evaporation end base plate and condensation end cover plate are processed using a CNC machine tool. After processing, they are cleaned. Radial microgrooves and straight microgrooves are machined on the evaporation end base plate. Corresponding holes of the non-central area support column and the central area support column are machined. The processed sample is cleaned with anhydrous ethanol, acetone and deionized water in sequence, and then air-dried and sealed for storage.

[0013] Step S2. Preparation of micro / nano mesh capillary cores: A femtosecond laser is used to process the mesh into a pre-designed shape to prepare a mesh structure. Multiple mesh structures are then sintered into concave positions by hot pressing to form multilayer mesh capillary cores. After sintering, the multilayer mesh capillary cores are subjected to electrodeposition. A mask is used to cover the other processed areas and is connected to the cathode electrode. The anode is connected to a copper plate. The electrolyte is copper sulfate solution with added sulfuric acid solution. The water bath temperature is controlled at 40-60℃, the input current is 10-200mA / cm2, and the deposition time is 600-4800s to prepare the micro / nano mesh capillary cores.

[0014] Step S3. Processing non-central area support columns and central area support columns: Select solid aluminum rods with a diameter of 4-8mm as raw materials for support columns. Use electrical discharge machining to cut the solid aluminum rods to the specified support column length, with a length range of 1-10mm. Clean and dry the cut aluminum columns. Use a nitrogen atmosphere furnace to sinter capillary structures on the aluminum columns. Use pure aluminum powder as the powder material, with a particle size of 100-300μm and a spherical shape. Use a graphite mold to shape and constrain the aluminum powder and aluminum columns. Sinter under a nitrogen atmosphere at a maximum sintering temperature of 400-650℃.

[0015] Step S4. Assemble and weld the evaporator end base plate, non-central area support column, central area support column, liquid injection pipe and condenser end cover plate into an aluminum-based heat spreader: After processing and assembling the evaporator end base plate, non-central area support column, central area support column, liquid injection pipe and condenser end cover plate, weld them using diffusion welding process. The diffusion welding temperature is 350-500℃ and the welding time is 60-180s. The entire process is carried out in a nitrogen atmosphere.

[0016] Step S5. Vacuuming and Liquid Injection: Perform a leak test on the welded aluminum-based heat spreader. Connect the vacuum pump to the liquid injection pipe. If the vacuum degree can reach 4.0×10-3 Pa, it can be considered that the vacuum degree is good, and start the vacuuming operation. After the vacuum degree is evacuated to 4.0×10-2 Pa, inject refrigerant R1233zd as the working fluid into the aluminum-based heat spreader through the liquid injection pipe. Finally, use sealing pliers to seal the liquid injection port.

[0017] Furthermore, in step S1, the radial microgrooves and the linear microgrooves are inclined V-shaped grooves, and the height difference of the V-shaped grooves is 1 mm.

[0018] Furthermore, in step S2, the number of multiple wire mesh structures is four, and hot pressing is carried out in a nitrogen atmosphere furnace for sintering, using a graphite mold as the hot pressing tool, and the sintering temperature is 400-650℃.

[0019] The concentration of copper sulfate solution is 0.1–0.4 mol / L, and the concentration of sulfuric acid solution is 0.05–0.5 mol / L.

[0020] Furthermore, in step S5, the filling volume of the working fluid is 95% of the void volume of all wire mesh structures, radial microgrooves, and straight microgrooves and inclined grooves.

[0021] Advantages of this invention: 1. This invention employs a fractal inclined groove structure as the internal structure of the vapor chamber. The conversion of potential energy into kinetic energy provides the driving force for the return of liquid within the vapor chamber. The fractal structure facilitates the directional diffusion of vapor and the reflux of edge condensate. Simultaneously, the groove fabrication is simpler and cheaper, significantly reducing the processing cost of the vapor chamber.

[0022] 2. The superposition of multiple layers of aluminum wire mesh will generate capillary force. This invention uses superimposed multi-layer wire mesh as the main evaporation surface inside the heat spreader, and at the same time performs micro-nano processing on the multi-layer wire mesh to further increase the capillary driving force.

[0023] 3. This invention uses aluminum as the raw material for processing the heat spreader, which significantly reduces the weight of the heat spreader itself and saves costs. At the same time, it uses the environmentally friendly refrigerant R1233zd as the working fluid, which has a boiling point of 18.7℃ and a freezing point of -107℃, and can meet the needs of use in all regions. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0025] Figure 2 This is a cross-sectional view of the evaporator end plate in this invention.

[0026] Figure 3 This is a schematic diagram of the fabrication process of the micro / nano mesh capillary core in this invention.

[0027] In the figure: 1. Evaporation end base plate, 110. Non-central area support column, 111. Radial microgroove, 112. Linear microgroove, 113. Central area support column, 114. Boss, 115. Micro-nano mesh capillary core, 1150. Mesh structure, 1151. Multilayer mesh capillary core, 2. Liquid injection tube, 3. Liquid injection port, 4. Condensation end cover plate. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention.

[0029] like Figure 1 As shown, a lightweight aluminum-based heat spreader structure with a wire mesh groove composite structure includes an evaporation end base plate 1, a liquid injection pipe 2, a liquid injection port 3, and a condensation end cover plate 4. The liquid injection port 3 is provided on one side of the evaporation end base plate 1, and the evaporation end base plate 1 is used as the site for evaporation phase change. The liquid injection port 3 is connected to the liquid injection pipe 2. The condensation end cover plate 4 is provided on the evaporation end base plate 1, and the condensation end cover plate 4 is used as the main site for liquid condensation.

[0030] like Figure 1 and Figure 2 As shown, the evaporator end base plate 1 includes a non-central area support column 110, radial microgrooves 111, linear microgrooves 112, a central area support column 113, a boss 114, and a micro / nano mesh capillary core 115. A boss 114 is provided at the center of the evaporator end base plate 1, and the boss 114 is used to contact the heat source. Four linear microgrooves 112 are provided along the four sides of the boss 114. Radial microgrooves 111 are provided at the remaining positions of the evaporator end base plate 1, except for the boss 114 and the four linear microgrooves 112. A micro / nano mesh capillary core 115 is provided in the concave part of the boss 114. A central area support column 113 is uniformly provided on the top of the micro / nano mesh capillary core 115. Non-central area support columns 110 are uniformly provided on the top of the radial microgrooves 111 and the four linear microgrooves 112.

[0031] As a preferred embodiment of the present invention, such as Figure 3 As shown, the micro / nano mesh capillary core 115 is prepared by chemical etching or deposition processes to generate micro / nano structures on the surface of multi-layer mesh capillary cores 1151. The multi-layer mesh capillary core 1151 is prepared by stacking multiple mesh structures 1150 through hot pressing. The mesh structure 1150 is prepared by processing the mesh into a pre-designed shape using a femtosecond laser.

[0032] In a preferred embodiment of the present invention, the height difference of the boss 114 is 5mm to 15mm, and a higher cross-sectional area is beneficial to the diffusion of vapor after evaporation.

[0033] In a preferred embodiment of the present invention, the fractal angle inside the radial microgrooves 111 is 5° to 45°, which is beneficial for more uniform vapor diffusion and for the heat spreader to have better temperature uniformity. There is a height difference between the radial microgrooves 111 at different positions and a height difference between the linear microgrooves 112 at different positions. The closer the radial microgrooves 111 and the linear microgrooves 112 are to the center, the lower their height, with a height difference ΔH of 0.5mm to 3mm. This is more conducive to the reflux of condensed liquid and its accumulation on the central protrusion 114, achieving the purpose of directional liquid delivery, increasing the liquid delivery volume and accelerating the evaporation-condensation cycle.

[0034] In a preferred embodiment of the present invention, the radial microgrooves 111 and the linear microgrooves 112 are U-shaped grooves, T-shaped grooves or V-shaped grooves. The characteristic dimensions of the radial microgrooves 111 and the linear microgrooves 112 are a depth of 0.1 mm to 1 mm and a spacing of 0.1 mm to 1 mm between adjacent grooves. The capillary effect in the grooves further improves the ability to directionally transport liquid.

[0035] In a preferred embodiment of the present invention, the multilayer wire mesh capillary core 1151 is prepared by stacking 2 to 8 wire mesh structures 1150. The capillary effect between the multilayer wire meshes allows the liquid flowing back to the protrusions 114 to rapidly diffuse and wet various positions of the micro / nano wire mesh capillary core 115, ensuring the wettability of the evaporation surface. Simultaneously, the multilayer wire mesh capillary core 1151 structure significantly increases the specific surface area of ​​the protrusions 114 on the evaporation surface, improving the heat transfer capacity on the evaporation side. The micro / nano wire mesh capillary core 115 can further enhance the capillary force and heat transfer surface area of ​​the evaporation surface, further strengthening the liquid transport capacity and evaporation heat transfer capacity.

[0036] A method for preparing a lightweight aluminum-based thermostatic plate structure with a wire mesh groove composite structure includes the following steps: Step S1. Preparation of evaporation end base plate 1 and condensation end cover plate 4: The evaporation end base plate 1 and condensation end cover plate 4 are processed using a CNC machine tool. After processing, they are cleaned. Radial microgrooves 111 and linear microgrooves 112 are processed on the evaporation end base plate 1. Corresponding holes of non-central area support column 110 and central area support column 113 are processed. The processed sample is cleaned with anhydrous ethanol, acetone and deionized water in sequence, and then air-dried and sealed for storage.

[0037] Step S2. Preparation of micro / nano mesh capillary cores 115: A femtosecond laser is used to process the mesh into a pre-designed shape to prepare a mesh structure 1150. Multiple mesh structures 1150 are then sintered to the concave position of 114 by hot pressing to form a multilayer mesh capillary core 1151. After sintering, the multilayer mesh capillary core 1151 is subjected to electrodeposition. A mask is used to cover the other processed areas and is connected to the cathode electrode. The anode is connected to a copper plate. The electrolyte is a copper sulfate solution with added sulfuric acid solution. The water bath temperature is controlled at 40-60℃, the input current is 10-200mA / cm2, and the deposition time is 600-4800s to prepare the micro / nano mesh capillary core 115.

[0038] Step S3. Processing the non-central area support column 110 and the central area support column 113: Select solid aluminum rods with a diameter of 4-8mm as the raw material for the support columns. Use electrical discharge machining to cut the solid aluminum rods to the specified support column length, with a length range of 1-10mm. Clean and dry the cut aluminum columns. Use a nitrogen atmosphere furnace to sinter capillary structures on the aluminum columns. Use pure aluminum powder as the powder material, with a particle size of 100-300μm and a spherical shape. Use a graphite mold to shape and constrain the aluminum powder and aluminum columns. Sinter under a nitrogen atmosphere at a maximum sintering temperature of 400-650℃.

[0039] Step S4. Assemble and weld the evaporator bottom plate 1, non-central area support column 110, central area support column 113, liquid injection pipe 2, and condenser end cover plate 4 into an aluminum-based heat spreader: After processing and assembling the evaporator bottom plate 1, non-central area support column 110, central area support column 113, liquid injection pipe 2, and condenser end cover plate 4, weld them using diffusion welding. The diffusion welding temperature is 350-500℃, the welding time is 60-180s, and the entire process is carried out in a nitrogen atmosphere.

[0040] Step S5. Vacuuming and Liquid Injection: Perform a leak test on the welded aluminum-based heat spreader. Connect the vacuum pump to the liquid injection pipe 2. If the vacuum degree can reach 4.0×10-3 Pa, it can be considered that the vacuum degree is good, and start the vacuuming operation. After the vacuum degree is evacuated to 4.0×10-2 Pa, inject refrigerant R1233zd as the working fluid into the aluminum-based heat spreader through the liquid injection pipe 2. Finally, use sealing pliers to seal the liquid injection port 3.

[0041] In a preferred embodiment of the present invention, in step S1, the radial microgrooves 111 and the linear microgrooves inclined grooves 112 are V-shaped grooves, and the height difference of the inclination of the V-shaped grooves is 1 mm.

[0042] In a preferred embodiment of the present invention, in step S2, there are four wire mesh structures 1150, and the hot pressing is carried out in a nitrogen atmosphere furnace with a graphite mold as the hot pressing tool and the sintering temperature is 400-650°C.

[0043] The concentration of copper sulfate solution is 0.1–0.4 mol / L, and the concentration of sulfuric acid solution is 0.05–0.5 mol / L.

[0044] In a preferred embodiment of the present invention, in step S5, the filling volume of the working fluid is 95% of the void volume of all wire mesh structures 1150, radial microgrooves 111 and straight microgrooves inclined grooves 112.

[0045] Table 1 shows a comparison of the performance and thermal resistance of this invention with other published aluminum-based heat spreaders:

[0046] Table 1 The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art can still adjust the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Therefore, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention also intends to include these modifications and variations.

Claims

1. A lightweight aluminum-based heat spreader structure with a wire mesh groove composite structure, characterized in that: It includes an evaporation end base plate (1), a liquid injection pipe (2), a liquid injection port (3), and a condensation end cover plate (4). The evaporation end base plate (1) is provided with a liquid injection port (3) on one side. The evaporation end base plate (1) is used as the place for evaporation phase change. The liquid injection port (3) is connected to the liquid injection pipe (2). The condensation end cover plate (4) is provided on the evaporation end base plate (1). The condensation end cover plate (4) is used as the main place for liquid condensation. The evaporation end base plate (1) includes a non-central area support column (110), radial microgrooves (111), linear microgrooves (112), a central area support column (113), a boss (114), and a micro-nano mesh capillary core (115). A boss (114) is provided at the center of the evaporation end base plate (1), and the boss (114) is used to contact the heat source. The evaporation end base plate (1) has four linear microgrooves (112) along the four sides of the boss (114). The evaporation end base plate (1) is provided with radial microgrooves (111) at the remaining positions except for the boss (114) and the four straight microgrooves (112). The inner recess of the boss (114) is provided with micro-nano mesh capillary cores (115). The top of the micro-nano mesh capillary cores (115) is uniformly provided with central area support columns (113). The top of the radial microgrooves (111) and the four straight microgrooves (112) is uniformly provided with non-central area support columns (110).

2. The lightweight aluminum-based heat spreader structure with wire mesh grooved composite structure according to claim 1, characterized in that: The micro / nano mesh capillary core (115) is prepared by chemical etching or deposition process to generate micro / nano structures on the surface of multi-layer mesh capillary cores (1151). The multi-layer mesh capillary core (1151) is prepared by stacking multiple mesh structures (1150) by hot pressing. The mesh structure (1150) is prepared by processing the mesh into a pre-designed shape using a femtosecond laser.

3. The lightweight aluminum-based heat spreader structure with wire mesh grooved composite structure according to claim 2, characterized in that: The height difference of the boss (114) is 5mm to 15mm.

4. The lightweight aluminum-based heat spreader structure with wire mesh grooved composite structure according to claim 3, characterized in that: The fractal angle inside the radial microgrooves (111) is 5° to 45°. There is a height difference between the radial microgrooves (111) at different positions and a height difference between the linear microgrooves (112) at different positions. The closer the radial microgrooves (111) and linear microgrooves (112) are to the center, the lower their height. The height difference ΔH is 0.5mm to 3mm.

5. The lightweight aluminum-based heat spreader structure with wire mesh grooved composite structure according to claim 4, characterized in that: The radial microgrooves (111) and linear microgrooves (112) are U-shaped, T-shaped, or V-shaped grooves. The characteristic dimensions of the radial microgrooves (111) and linear microgrooves (112) are a depth of 0.1 mm to 1 mm and a spacing of 0.1 mm to 1 mm between adjacent grooves.

6. The lightweight aluminum-based heat spreader structure with wire mesh grooved composite structure according to claim 5, characterized in that: The multilayer wire mesh capillary core (1151) is prepared by stacking 2 to 8 wire mesh structures (1150).

7. A method for preparing a lightweight aluminum-based heat spreader structure with a wire mesh groove composite structure, characterized in that, Includes the following steps: Step S1. Prepare the evaporation end base plate (1) and the condensation end cover plate (4): Use a CNC machine tool to process the evaporation end base plate (1) and the condensation end cover plate (4), and clean them after processing. Process radial micro-grooves (111) and straight micro-grooves inclined grooves (112) on the evaporation end base plate (1). Process the corresponding holes of the non-central area support column (110) and the central area support column (113). Clean the processed sample with anhydrous ethanol, acetone and deionized water in sequence, and air dry and seal it for storage. Step S2. Preparation of micro / nano wire mesh capillary cores (115): The wire mesh is processed into a pre-designed shape using a femtosecond laser to prepare a wire mesh structure (1150). Multiple wire mesh structures (1150) are sintered to the concave position of (114) by hot pressing to form a multilayer wire mesh capillary core (1151). After sintering, the multilayer wire mesh capillary core (1151) is subjected to electrodeposition treatment. The other processed areas are covered by a mask and connected to the cathode electrode. The anode is connected to a copper plate. The electrolyte is copper sulfate solution, and sulfuric acid solution is added. The water bath temperature is controlled at 40-60℃, the input current is 10-200mA / cm2, and the deposition time is 600-4800s to prepare the micro / nano wire mesh capillary core (115). Step S3. Processing non-central area support column (110) and central area support column (113): Select solid aluminum rods with a diameter of 4-8 mm as raw materials for support columns. Use electrical discharge machining to cut the solid aluminum rods to the specified support column length, with a length range of 1-10 mm. Clean and dry the cut aluminum columns. Use a nitrogen atmosphere furnace to sinter capillary structures on the aluminum columns. Use pure aluminum powder as powder, with a particle size of 100-300 μm and a spherical shape. Use a graphite mold to shape and constrain the aluminum powder and aluminum columns. Sinter in a nitrogen atmosphere with a maximum sintering temperature of 400-650℃. Step S4. Assemble and weld the evaporator bottom plate (1), non-central area support column (110), central area support column (113), liquid injection pipe (2) and condenser end cover plate (4) into an aluminum-based heat spreader: After processing and assembling the evaporator bottom plate (1), non-central area support column (110), central area support column (113), liquid injection pipe (2) and condenser end cover plate (4), use diffusion welding process to weld them. The diffusion welding temperature is 350~500℃ and the welding time is 60~180s. The whole process is carried out in a nitrogen atmosphere. Step S5. Vacuuming and liquid injection: The welded aluminum-based heat spreader is subjected to a leak test. The vacuum pump is connected to the liquid injection pipe (2). If the vacuum degree can reach 4.0×10-3Pa, it can be considered that the vacuum degree is good, and the vacuuming operation is started. After the vacuum degree is evacuated to 4.0×10-2Pa, the refrigerant R1233zd is injected into the aluminum-based heat spreader through the liquid injection pipe (2) as the working fluid. Finally, the liquid injection port (3) is sealed with sealing pliers.

8. The preparation method according to claim 7, characterized in that: In step S1, the radial microgrooves (111) and the linear microgrooves inclined grooves (112) are V-shaped grooves, and the height difference of the V-shaped grooves is 1 mm.

9. The preparation method according to claim 8, characterized in that: In step S2, there are four wire mesh structures (1150), and the hot pressing is carried out in a nitrogen atmosphere furnace with a graphite mold as the hot pressing tool. The sintering temperature is 400-650℃. The concentration of copper sulfate solution is 0.1–0.4 mol / L, and the concentration of sulfuric acid solution is 0.05–0.5 mol / L.

10. The preparation method according to claim 9, characterized in that: In step S5, the filling volume of the working fluid is 95% of the void volume of all wire mesh structures (1150), radial microgrooves (111), and straight microgrooves and inclined grooves (112).

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