Heat dissipation plate and its modified manufacturing method

Abstract

A heat spreader includes a hollow plate body, a cavity space is provided inside the hollow plate body, a modified super-hydrophilic microstructure layer is provided on the surface of the top side of the cavity space, a multi-porous structure for adsorbing a working fluid is provided on the bottom side of the cavity space, an air chamber with a thickness of less than 0.4 mm is provided between the surface of the top side of the cavity space and the multi-porous structure, and a plurality of guide pillars are dispersed in the air chamber to support the air chamber and guide the working fluid; when the heat spreader is used for heat conduction, after the working fluid evaporates in the evaporation zone of the multi-porous structure, it condenses to form a liquid film when it contacts the surface of the super-hydrophilic microstructure layer on the top side of the cavity space, and then flows back to the evaporation zone along the surrounding wall or the surface of each guide pillar, which can avoid the ultra-thin heat spreader from accumulating large water columns in the air chamber to hinder the evaporation and flow of the working fluid, thereby improving the efficiency of capillary force, condensed liquid reflux and heat dissipation.

Description

Technical Field

[0001] The present invention relates to a heat dissipation device and a manufacturing method thereof; in particular, to a heat spreader and a modified manufacturing method thereof. Background Art

[0002] The structure of a conventional vapor chamber consists of a joined upper and lower cover, with a low-vacuum chamber inside. A working fluid is placed within the chamber, dividing the space into an evaporation zone and a condensation zone. When heat is transferred from the heat source to the evaporation zone, the working fluid absorbs the thermal energy, rapidly expanding and transforming into vapor, which then moves toward the lower-pressure condensation zone. When the vapor contacts the walls of the condensation zone, it condenses, releasing heat. It then condenses back into liquid and drips back into the evaporation zone, or flows back to the evaporation zone due to capillary action along the chamber walls, forming a circulating heat dissipation system.

[0003] Because the thermal resistance of thin-film condensation caused by the hydrophilic surface of the working fluid condensing on the vapor chamber's condensation zone is greater than the thermal resistance of droplet condensation caused by the hydrophobic surface, existing vapor chambers, even those designed to be thin, follow this design philosophy: the evaporation zone walls are designed to be as hydrophilic as possible, and the walls surrounding the condensation zone are designed to be as hydrophobic as possible. Generally, a surface is considered hydrophilic when its contact angle with a water droplet is between 10 and 90 degrees, hydrophobic when it is between 90 and 120 degrees, and super-hydrophilic when it is less than 10 degrees or even 0 degrees.

[0004] However, the existing vapor chamber design described above forms a hydrophobic layer on the inner surface of the upper cover, causing the vapor of the working fluid to condense on the inner wall of the upper cover and then drip down. Although such a vapor chamber structure is generally suitable for use and even has good heat dissipation efficiency, the inventors discovered through experiments and observations that once the thickness of the vapor chamber and its cavity is reduced to an ultra-thin level of less than 1 mm, the droplets of the working fluid will begin to accumulate and connect in series on the microstructure of the lower cover to form water columns. The formation of the water columns not only hinders the subsequent upward flow of the working fluid vapor, but also creates flow resistance to the capillary flow of the working fluid back to the evaporation zone. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide an ultra-thin heat spreader whose internal space is thinner than the size of existing heat spreaders. By forming a super-hydrophilic microstructure layer on the surface of the heat spreader, the vapor of the working fluid condenses to form a water film, which then flows back along the surrounding surface and the surface of each guide pillar to prevent the droplets from forming large water columns. This achieves the effect of not hindering the flow of vapor and liquid of the working fluid, thereby improving the capillary force, the condensed liquid backflow, and the heat dissipation efficiency.

[0006] To achieve the above-mentioned objectives, the present invention provides a vapor chamber comprising a hollow plate body, a porous structure, and a plurality of guide posts. The hollow plate body defines a cavity, the top surface of which comprises a modified super-hydrophilic microstructure layer. The porous structure is disposed on the bottom of the cavity and is configured to adsorb a working fluid. An air chamber is defined between the top surface of the cavity and the porous structure, with a thickness of no greater than 0.4 mm. The plurality of guide posts are dispersed within the air chamber and serve to support the chamber.

[0007] Preferably, the hollow plate body includes an upper cover and a lower cover docked with the upper cover, the upper cover has an upper groove, and the modified super-hydrophilic microstructure layer is located on the surface of the upper groove; the lower cover has a lower groove, and the lower groove is connected to the upper groove to form the cavity space; the porous structure is arranged in the lower groove, and the air chamber is located between the upper groove and the porous structure.

[0008] To achieve the above-mentioned objectives, the present invention provides a method for manufacturing a vapor chamber, the method comprising steps of preparing vapor chamber components, performing a thermal oxidation process, bonding the vapor chamber components, and completing the vapor chamber product. The heat spreader assembly is prepared by preparing a heat spreader, comprising an upper cover, a lower cover and a porous structure, wherein the upper cover has an upper groove, the lower cover has a lower groove, a plurality of guide posts are arranged in the upper groove, and the porous structure is arranged in the lower groove; the thermal oxidation process is to place the upper cover, the lower cover and the porous structure of the heat spreader into a heating furnace, inject oxygen into the heating furnace, and continuously heat for 30 minutes at a temperature of 450°C, a heating and cooling rate of 10°C / min, and an oxygen flow rate of 200 sccm, and then cool down in a furnace cooling manner, thereby forming a super-hydrophilic microstructure layer at least on the surface of the upper groove; the heat spreader assembly is to join the upper cover and the lower cover, and an air chamber is formed between the upper groove and the porous structure, and the thickness of the air chamber is 0.4 mm or less, a water inlet communicating with the air chamber is provided around the heat spreader; the heat spreader is completed by filling water into the water inlet of the heat spreader, evacuating the water, and then sealing the inlet to complete the heat spreader.

[0009] The effect of the present invention is that a heat spreader is manufactured through a modified manufacturing method to form a super-hydrophilic microstructure layer on the surface of at least the top side of the cavity space, so that when the ultra-thin heat spreader is used for heat conduction, the working fluid evaporated from the evaporation zone on one side of the porous structure will condense into a water film on the surface of the super-hydrophilic microstructure layer when it contacts the colder surface of the top side of the cavity space, and will not drip. The water film can make full use of the limited air chamber space and flow back to the porous structure along the wall around the air chamber or the surface of each guide column to circulate continuously, thereby avoiding the formation of large water columns that hinder the flow of vapor and liquid of the working fluid, and avoiding the chance of premature condensation of vapor when it contacts the multiple water columns, which has the effect of improving capillary force, improving the efficiency of condensed liquid reflux and heat dissipation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a cross-sectional schematic diagram of a preferred embodiment of the present invention.

[0011] Figure 2 It is a schematic diagram of the use and implementation of the above preferred embodiment of the present invention.

[0012] Figures 3A to 3B This is an electron microscope image of the super-hydrophilic microstructure layer on the upper groove surface.

[0013] Figures 4A to 4B This is an electron microscope image of the super-hydrophilic microstructure layer on the copper mesh surface.

[0014] Figure 5 This is a flow chart of the steps for improving and manufacturing a vapor chamber according to the preferred embodiment of the present invention.

[0015] Figure 6 Schematic diagram of the modification process of the above preferred embodiment of the present invention.

[0016] Figure 7 This is a diagram showing the setup for testing the thermal performance of the vapor chamber according to the preferred embodiment of the present invention.

[0017] Figures 8A to 8B Coordinate diagram of heating power and cycle thermal resistance for horizontal and vertical detection.

[0018] Figures 9A to 9B Coordinate diagram of heating power and temperature difference between two points for horizontal and vertical detection. DETAILED DESCRIPTION

[0019] In order to explain the present invention more clearly, preferred embodiments are given and described in detail with reference to the accompanying drawings. Figures 1 to 2FIG. 1 shows a vapor chamber 100 according to a preferred embodiment of the present invention. To achieve good heat conduction and heat dissipation, the vapor chamber 100 is preferably made entirely of copper, a good thermal conductor, and includes a hollow plate 10, a porous structure 20, and a plurality of guide posts 30.

[0020] The hollow plate body 10 includes an upper cover 12 and a lower cover 14 docked with the upper cover 12, the upper cover 12 has an upper groove 121, the surface of the upper groove 121 has a modified super-hydrophilic microstructure layer A, preferably, the contact angle of water droplets dropped on the surface of the super-hydrophilic microstructure layer A with the surface is close to 0 degrees, so it is a super-hydrophilic surface structure; the lower cover 14 has a lower groove 141, the periphery of the lower cover 14 and the periphery of the upper cover 12 are docked with each other by welding, so that the lower groove 141 and the upper groove 121 are connected to form the cavity space C inside the hollow plate body 10.

[0021] The porous structure 20 can be a copper mesh structure bonded to the lower groove 141, or a sintered or etched structure formed in the lower groove 141. In this preferred embodiment, the porous structure 20 is a copper mesh structure bonded to the lower groove 141, thereby disposed on the bottom side of the cavity space C. Its wire diameter is 0.04 mm and its mesh size is 250 mesh. The porous structure 20 is used to adsorb a working fluid B. An air chamber 16 is provided between the top wall of the upper groove 121 (the surface of the top side of the cavity space C) and the top surface of the porous structure 20. The thickness of the air chamber 16 is less than 0.4 mm. Preferably, the thickness H of the air chamber 16 is 0.05 to 0.3 mm. The thickness H of the air chamber 16 makes the overall thickness of the vapor chamber 100 significantly thinner than that of a conventional vapor chamber, and therefore the vapor chamber 100 is referred to as an ultra-thin vapor chamber.

[0022] A plurality of guide posts 30 are dispersed within the air chamber 16 and serve to support the chamber 16, preventing the inner wall of the upper cover 12 from collapsing toward the lower cover 14. Furthermore, when the vapor chamber 100 is in operation, the surfaces of the guide posts 30 guide the water film back into the porous structure 20 for reflow. Preferably, each guide post 30 has a diameter of 1 mm, and the spacing between adjacent guide posts 30 is 3 mm.

[0023] In the preferred embodiment described above, the cavity space C within the hollow plate body 10 includes the upper groove 121 and the lower groove 141, but the present invention is not limited thereto. For example, in other preferred embodiments, the groove may be provided only in the upper cover 12 or only in the lower cover 14, and then another flat lower cover 14 or upper cover 12 may be combined to seal the groove to form the hollow plate body 10. Such a structure can also provide the cavity space C within the hollow plate body 10.

[0024] When the above-mentioned vapor chamber 100 is used for heat conduction and heat dissipation, please refer to Figure 1 and Figure 2 As shown, the heat source X is brought into contact with one side of the lower cover 14. The working fluid B adsorbed by the porous structure 20 within the lower recess 141 evaporates into gas due to the heat. For ease of explanation of the operation of the working fluid B, the region where the working fluid B evaporates into gas is referred to as the evaporation zone. Once the working fluid B evaporates into gas, it rapidly flows toward the surrounding areas of lower pressure, specifically toward the periphery of the gas chamber 16. When the gas contacts the cooler area within the upper recess 121, particularly the surface, condensation occurs. Therefore, the surface of the upper recess 121 is referred to as the condensation zone.

[0025] When the vapor of the working fluid B cools down and condenses in the condensation zone, due to the super-hydrophilic property of the super-hydrophilic microstructure layer A being completely wet, the condensed working fluid B condenses into a water film at the location and does not drip directly toward the porous structure 20. Therefore, a large water column that obstructs the flow of gas will not be formed due to the continuous water droplets in the air chamber 16 with an ultra-thin thickness H and limited space. This can avoid obstructing the flow of gas generated by the subsequent evaporation of the working fluid B, or obstructing the working fluid B condensed into a water film from flowing back toward the porous structure 20 along the surface of each of the guide pillars 30 or the wall surface around the upper groove 121. It can also avoid the vapor from condensing into liquid due to premature contact with a large water column before reaching the condensation zone, thereby avoiding a reduction in the operating efficiency of the thermal cycle of the working fluid B.

[0026] Working fluid B, which reflows into the porous structure 20, is replenished to the evaporation zone, which has dried up due to evaporation, due to the capillary effect enhanced by the porous structure 20. This causes the working fluid B in that zone to boil again as a gas due to the heat, continuing to circulate. The reflowing working fluid B also helps the bubbles of evaporating working fluid B escape from the evaporation zone, achieving a higher heat flux. The present invention utilizes the ultra-thin vapor chamber 100 with a super-hydrophilic microstructure layer A on the surface of the upper groove 121, allowing the working fluid B to adapt to the ultra-thin gas chamber 16 of thickness H. It diffuses between the evaporation zone and the condensation zone in the evaporated gaseous state before reflowing in a thin film of liquid, continuously circulating, thus forming an effective circulating heat dissipation system.

[0027] The detailed structure of the above preferred embodiment will be further described. The upper groove 121 of the upper cover 12 is formed by etching a copper metal sheet with a thickness of 0.2 mm to a depth of 0.15 mm. At the same time as the upper groove 121 is etched on the upper cover 12, the plurality of guide posts 30 are formed and connected to the surface of the upper groove 121. The lower groove 141 of the lower cover 14 is formed by etching a copper metal sheet with a thickness of 0.1 mm to a depth of 0.05 mm. The porous structure 20 of the copper mesh bonded to the lower groove 141 has a thickness of 0.05 mm. In this case, the thickness H of the air chamber 16 is 0.15 mm.

[0028] In the above preferred embodiment, the vapor chamber 100, in addition to having a modified super-hydrophilic microstructure layer A on the surface of the upper groove 121, may also have another modified super-hydrophilic microstructure layer A formed on one or both of the surfaces of the guide pillars 30 and the porous structure 20, or may also have the super-hydrophilic microstructure layer A formed on the surface of the lower groove 141. Figures 3A to 4B As shown, each of the hydrophilic microstructures A is a nano-copper oxide microstructure, and each has a plurality of copper oxide nanowires A1, wherein Figures 3A to 3B The super-hydrophilic microstructure layer A and its multiple nanowires A1 on the surface of the upper groove 121 and the surface of each guide post 30 are shown. Figures 4A to 4B The super-hydrophilic microstructure layer A and its multiple nanowires A1 of the porous structure 20 of the copper mesh are shown. The super-hydrophilic microstructure layer A formed on the surface of the porous structure 20 can further enhance the capillary force, so that after the working fluid B flows back to the porous structure 20, it can flow faster to the heated evaporation area to undergo another evaporation and condensation cycle.

[0029] Preferably, the diameter of each of the nanowires A1 is 50 to 400 nm, the length is 1 to 10 μm, the density of the area occupied by the multiple nanowires A1 in a unit area is 20 to 70%, and each super-hydrophilic microstructure layer A can generate a super-hydrophilic phenomenon when in contact with a liquid through the multiple nanowires A1, so that the liquid can form a water film on the surface of each super-hydrophilic microstructure layer A and have better capillary force.

[0030] The aforementioned super-hydrophilic microstructure layers A, benefiting from the extremely low thermal resistance and increased contact area of ​​the structure of the multiple nanowires A1, can further increase the heat flux on the surfaces thereof, such as the surface of the upper groove 121, the surface of the lower groove 141, the surface of the porous structure 20, and the surfaces of the guide pillars 30, thereby improving the efficiency of heat exchange. For example, the water flow caused by the capillary phenomenon of the porous structure 20 can promote the detachment of bubbles evaporated by the working fluid B in the evaporation zone. After the super-hydrophilic microstructure layer A is formed on the surface of the porous structure 20, the multiple nanowires A1 can further reduce the thermal resistance of the porous structure 20, increase the area of ​​heat conduction, promote the boiling of the working fluid B, improve the boiling efficiency, reduce the evaporation thermal resistance, and improve the heat exchange efficiency and thermal performance of the heat exchange plate 100.

[0031] In the above preferred embodiment, the vapor chamber 100 is manufactured by a modified vapor chamber manufacturing method. Figure 5 As shown in the flowchart, the steps of the modified manufacturing method include:

[0032] Prepare the heat sink assembly: please refer to Figure 6 As shown, a heat spreader 100 is provided, comprising an upper cover 12, a lower cover 14, and a porous structure 20. The upper cover 12 is a copper metal sheet and has an upper groove 121 formed therein through an etching process. The lower cover 14 is a copper metal sheet and has a lower groove 141 formed therein through an etching process. When the upper groove 121 is etched on the upper cover 12, a plurality of guide posts 30 are simultaneously formed and connected to the surface of the upper groove 121. The porous structure 20 is disposed in the lower groove 141. In this preferred embodiment, the porous structure 20 is a copper mesh structure with a wire diameter of 0.04 mm and a mesh size of 250 mesh.

[0033] Preferably, the porous structure 20 can also be a sintered structure or an etched structure, and the dimensions of each component are that the thickness of the upper cover 12 and the lower cover 14 are 0.2 mm and 0.1 mm respectively, the etching depths of the upper groove 121 and the lower groove 141 are 0.15 mm and 0.05 mm respectively, the diameter of each guide column 30 is 1 mm, and the distance between two adjacent guide columns 30 is 3 mm.

[0034] Join the components of the heat spreader: The upper cover 12 and the lower cover 14 are joined by welding, so that the heat spreader 100 becomes a thin sheet-shaped hollow plate body 10 with the cavity space C inside. Please refer to Figure 1As shown, the upper groove 121 and the lower groove 141 are connected to form the cavity space C, and an air chamber 16 is formed between the wall surface on the top side of the upper groove 121 inside the heat spreader 100 and the porous structure 20. The thickness H of the air chamber 16 is less than 0.4 mm, and a water inlet 18 connected to the air chamber 16 is provided around the heat spreader 100.

[0035] Thermal oxidation process: The upper cover 12, the lower cover 14, and the porous structure 20 of the vapor chamber 100 are placed in a heating furnace 40. Oxygen is injected into the furnace 40. The heating is continued for 30 minutes at a temperature of 450°C, a ramp rate of 10°C / min, and an oxygen flow rate of 200 sccm. The temperature is then cooled by furnace cooling. A super-hydrophilic microstructure layer A is formed at least on the surface of the upper recess 121. Preferably, during the thermal oxidation process, the surfaces of the upper recess 121, the lower recess 141, the porous structure 20, and the guide posts 30 are modified to form the super-hydrophilic microstructure layer A. The super-hydrophilic microstructure layer A comprises a plurality of copper oxide nanowires A1.

[0036] Testing and Analysis of Modification Results: After the thermal oxidation process described above is completed, the vapor chamber 100 is tested and analyzed for modification results, including contact angle testing, capillary force testing, and microstructure morphology and phase analysis. During the contact angle test, a contact angle meter is used to compare the wettability of a test piece of the modified, thermally oxidized copper mesh with the porous structure 20 and an unoxidized copper mesh. Each test droplet size is 5 μl, and the contact angle between the droplet and the copper mesh is measured and recorded using a high-speed camera. The contact angle test indicates that the contact angle between the droplet and the copper mesh on the modified surface of this preferred embodiment is 0 degrees, compared to the 95-degree contact angle of the untreated copper mesh, indicating complete wetting and a super-hydrophilic state.

[0037] To test capillary force, the lower cover 14 of the porous structure 20 with copper mesh was positioned vertically in a climbing tester. The bottom of the lower cover 14 was immersed in liquid in a petri dish. The depth of immersion was 1 cm. A graduated ruler was placed next to the lower cover 14 to record the time it took to reach the top of the copper mesh. The test showed that the porous structure 20 with the modified surface of this preferred embodiment climbed in 20 seconds, significantly better than the untreated copper mesh, which had no capillary force.

[0038] When conducting microstructure morphology and phase analysis, the porous structure 20 of the modified thermally oxidized copper mesh is observed by electron microscope, such as Figures 3A to 4BAs shown, the diameter of each nanowire A1 is 50 to 400 nm and the length is 1 to 10 μm. The area occupied by the multiple nanowires A1 in a unit area is analyzed by imaging software, and the density of the multiple nanowires A1 in the unit area is 20 to 70%, and the density is 0.5 to 3 nanowires / μm. 2 , preferably 1.4 pieces / μm 2 the number of; Raman spectrometer and X-ray diffraction detection of the aforementioned test piece, confirming the super hydrophilic microstructure layer A plurality of nanowires A1 is copper oxide nanowires.

[0039] Finished vapor chamber: Water is poured into the vapor chamber 100 through the water inlet 18 and vacuumed, then the water inlet 18 is sealed. This completes the vapor chamber 100. After the finished product is completed, the vapor chamber 100 is tested for thermal performance and reliability.

[0040] When conducting the above thermal performance test, the test environment is to adopt natural heat dissipation, horizontal and vertical placement for measurement, the ambient temperature is 25±1℃, and the starting temperature of the heat source is 30±1℃. Figure 7 As shown, the heat source X is set on the bottom surface of the vapor chamber 100 to be tested, a first temperature measurement point P1 is set at the position corresponding to the heat source X on the top surface of the vapor chamber 100, and a second temperature measurement point P2 is set at a peripheral position at a certain distance from the heat source X. The temperature measured at the first temperature measurement point P1 is T1, and the temperature measured at the second temperature measurement point P2 is Tc. The formula for the temperature difference ∆T (in °C) between the first temperature measurement point P1 and the second temperature measurement point P2 is ∆T=Tc-T1, and the heating power Q of the heat source X supplied by the DC power supply is in (Unit is Watt) The formula is Qin (heating power) = I (current) × V (voltage), the above Q in Substitute the parameters of ∆T into the following formula for the loop thermal resistance Rc:

[0041] Rc (circulation thermal resistance) = ∆T / Q in

[0042] The circulating thermal resistance Rc (unit: °C / W) can be calculated. The values ​​of the vapor chamber 100 after thermal oxidation modification of the present invention and the vapor chamber of conventional manufacturing process are measured in horizontal and vertical positions, with the horizontal axis representing the heating power of the heat source and the vertical axis representing the circulating thermal resistance Rc. Figure 8A 、 Figure 8B The values ​​of the heat spreader 100 of the present invention and the general heat spreader when placed horizontally and vertically are measured, with the horizontal axis being the heating power of the heat source and the vertical axis being the temperature difference ∆T between two points. Figure 9A 、 Figure 9B shown.

[0043] From the above Figures 8A to 9B As can be seen from the coordinate graphs of heating power and cycle thermal resistance, as well as the coordinate graphs of heating power and two-point temperature difference, the maximum operating wattage of a conventional vapor chamber is 3 to 4 Watts during normal operation. However, the maximum operating wattage of the vapor chamber 100 after thermal oxidation modification of the present invention can be increased to a heat source of 9 Watts during normal operation. Compared with an unmodified conventional vapor chamber, it has significantly better thermal performance and is not affected by vertical or horizontal placement.

[0044] The above description is only a preferred embodiment of the present invention. Any equivalent changes made by applying the description of the present invention and the scope of the patent application should be included in the patent scope of the present invention.

[0045] Description of Reference Numerals

[0046] [The present invention]

[0047] 100: Vapor chamber

[0048] 10: Hollow plate

[0049] 12: Upper cover

[0050] 121: Upper groove

[0051] 14: Lower cover

[0052] 141: Lower groove

[0053] 16: Air Chamber

[0054] 20: Porous structure

[0055] 30: Guide column

[0056] A: Super hydrophilic microstructure layer

[0057] A1: Nanowires

[0058] B: Working fluid

[0059] C: cavity space

[0060] H: thickness

[0061] P1: First temperature measurement point

[0062] P2: Second temperature measurement point

[0063] X: Heat Source

Claims

1. A vapor chamber, comprising: A hollow plate body having a cavity space inside; a porous structure disposed on the bottom side of the cavity space and used to adsorb a working fluid, an air chamber being defined between the surface of the top side of the cavity space and the porous structure, wherein the thickness of the air chamber is less than 0.4 mm; as well as A plurality of guide posts are dispersed in the air chamber and used to support the air chamber; wherein the surface of each guide post and the surface of the porous structure respectively have a modified super-hydrophilic microstructure layer, each of the hydrophilic microstructures is a nano-copper oxide microstructure and has a plurality of nanowires, each of the nanowires has a diameter of 50 to 400 nm and a length of 1 to 10 μm.

2. The vapor chamber according to claim 1, wherein: The hollow plate body includes an upper cover and a lower cover docked with the upper cover, the upper cover has an upper groove, and the modified super-hydrophilic microstructure layer is located on the surface of the upper groove; the lower cover has a lower groove, and the lower groove is connected to the upper groove to form the cavity space; the porous structure is arranged in the lower groove, and the air chamber is located between the upper groove and the porous structure.

3. The vapor chamber according to claim 2, wherein: The multi-porous structure is a copper mesh structure combined with the lower groove or a sintering structure or etching structure formed in the lower groove, and each of the guide posts is connected to the surface of the upper groove.

4. The vapor chamber according to claim 1, wherein: The density of the area occupied by the plurality of nanowires per unit area is 20 to 70%.

5. The vapor chamber according to any one of claims 1 to 3, wherein: The thickness of the air chamber is 0.05 to 0.3 mm.

6. A method for manufacturing a vapor chamber according to any one of claims 1 to 3, wherein the method comprises the following steps: Prepare a vapor chamber assembly: Prepare a vapor chamber assembly, comprising an upper cover, a lower cover, and a porous structure, wherein the upper cover has an upper groove, the lower cover has a lower groove, a plurality of guide posts are arranged in the upper groove, and the porous structure is arranged in the lower groove; A vapor chamber assembly is provided: the upper cover and the lower cover are joined to form a hollow plate body, the upper groove and the lower groove are connected to form a cavity space, an air chamber is formed between the upper groove and the porous structure, the thickness of the air chamber is less than 0.4 mm, and a water inlet is provided around the vapor chamber and connected to the air chamber; Thermal oxidation process: placing the upper cover, the lower cover, and the porous structure of the vapor chamber into a heating furnace, injecting oxygen into the heating furnace, heating at 450°C, a heating and cooling rate of 10°C / min, and an oxygen flow rate of 200 sccm for 30 minutes, and then cooling by furnace cooling. Then, a super-hydrophilic microstructure layer is formed on the surface of the upper groove, the surface of each of the guide pillars, and the surface of the porous structure. Each of the hydrophilic microstructures is a nano-copper oxide microstructure and has a plurality of nanowires. Each of the nanowires has a diameter of 50 to 400 nm and a length of 1 to 10 μm. The vapor chamber is finished: the vapor chamber is sealed after water is injected into the water inlet of the vapor chamber and vacuum is drawn.

7. The method for manufacturing a vapor chamber according to claim 6, wherein: The density of the area occupied by the plurality of nanowires per unit area is 20 to 70%.

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