An ultra-thin vapor chamber and electronic device
By designing an ultra-thin heat spreader in smartphones, and utilizing the capillary network of evaporation and condensation plates and the golden spiral mesh structure, the problem of low heat dissipation efficiency in smartphones is solved, achieving efficient heat transfer and uniform heat dissipation.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- GUANGDONG UNIV OF TECH
- Filing Date
- 2025-08-28
- Publication Date
- 2026-07-21
AI Technical Summary
In existing technologies, the heat dissipation problem of smartphones is difficult to solve effectively in a limited space. Traditional heat dissipation methods are inefficient, cannot meet the requirements of lightweight design, and have long heat transfer paths, resulting in poor heat dissipation.
Design an ultrathin heat spreader with a structure consisting of an evaporator cover plate and a condenser cover plate. It has an internal capillary flow channel network, and the cooling medium flows autonomously through capillary force and Laplace pressure difference. Combined with a golden spiral mesh structure, it improves space utilization and heat dissipation efficiency.
It achieves efficient heat transfer and uniform heat dissipation in an ultra-thin structure, improving the heat dissipation performance of electronic devices and making it suitable for small electronic devices such as smartphones.
Smart Images
Figure CN224538608U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of heat dissipation technology for electronic devices, and more specifically, to an ultra-thin heat spreader and electronic device. Background Technology
[0002] The heat dissipation problem of smartphones directly affects the performance of the phone and the user experience. With the popularization of technologies such as AI computing, high refresh rate screens, and high-performance CPUs, the power consumption of current smartphones has increased significantly. The internal components of smartphones, such as processors, camera modules, and batteries, generate a lot of heat. Traditional graphite sheet heat dissipation can only transfer heat in a two-dimensional plane, which is inefficient for dissipating heat from point heat sources such as chips and easily leads to heat accumulation. Using metal back plates or metal frames for heat dissipation is difficult to meet the lightweight design of smartphones, and the long heat transfer path also results in low heat dissipation efficiency. Using copper pipes for heat dissipation cannot evenly cover multiple heat sources.
[0003] Chinese patent CN201020104320.9 discloses a vapor chamber with a condensation section on top and an evaporation section on the bottom. The condenser plate in the condensation section and the evaporator plate in the evaporation section are welded together. A working medium is filled into the cavity formed after the condenser plate and the evaporator plate are combined. A layer of copper powder is sintered on each side of both the condenser plate and the evaporator plate. This sintered copper powder layer generates capillary force under the condition of being filled with working fluid. This solution can optimize the structure of the vapor chamber, fully explore its potential, and make it practically applicable to the heat dissipation of micro electronic devices. Different cooling methods can be adopted according to different heat dissipation requirements. It is suitable for cooling computer chips and LED lighting equipment, high-energy electronic chips, optoelectronic chips, or radio frequency chips in the wireless or wired communication industry. It is also suitable for cooling high-energy heat-generating components inside military radar, laser equipment, medical devices, or aerospace equipment. However, this solution, with its double sintered layer structure of condensation and evaporation surfaces, suffers from large flow resistance, resulting in poor heat dissipation. Utility Model Content
[0004] The purpose of this utility model is to overcome the shortcomings of the prior art. This utility model proposes an ultra-thin heat spreader and electronic equipment, which can improve the heat dissipation performance of the ultra-thin heat spreader and solve the heat dissipation problem of high heat flux in electronic equipment.
[0005] To achieve the above objectives, this solution provides an ultrathin heat spreader, comprising a thermally conductive evaporator cover plate, a condenser cover plate, and a cooling medium. The evaporator cover plate and the condenser cover plate are fitted together and sealed, forming a cavity between them. The cooling medium is disposed within the cavity. The inner surfaces of the opposing evaporator cover plate and the condenser cover plate are respectively provided with a network of grooves through which the cooling medium can flow. The groove network includes at least one converging area and several capillary flow channels radiating outwards from the converging area. Each capillary flow channel includes a microchannel with a narrow opening at one end and a wide opening at the other end. The narrow and wide openings of several microchannels are sequentially connected end-to-end. The converging groove network on the evaporator cover plate and the condenser cover plate... The zones correspond one-to-one. The narrow openings of the microchannels on the evaporator cover plate face the converging zone of the evaporator cover plate. The narrow opening of the last stage microchannel of each capillary flow groove on the evaporator cover plate is connected to the converging zone on the evaporator cover plate. The wide openings of the microchannels on the condenser cover plate face the converging zone of the condenser cover plate. The wide opening of the last stage microchannel of each capillary flow groove on the condenser cover plate is connected to the converging zone on the condenser cover plate. The converging zone on the condenser cover plate collects the cooling medium to form a highly elongated liquid column. The liquid column can connect with the converging zone on the evaporator cover plate to establish a connected circulation relationship between the groove network on the evaporator cover plate and the groove network on the condenser cover plate. The volume ratio of the cooling medium in the cavity is 10-70%.
[0006] In this technical solution, the evaporation cover plate is close to the heat-generating position of the electronic device. When the cooling medium is in the capillary flow channel, due to the Laplace pressure difference and capillary force, the cooling medium will spontaneously flow from the narrow opening to the wide opening of each microchannel. Therefore, the cooling medium can achieve spontaneous flow in the capillary flow channel composed of multiple microchannels connected in sequence.
[0007] During operation, the heat generated by the electronic equipment causes the cooling medium on the evaporator cover to evaporate into steam from the collection area and diffuse outwards under the guidance of the capillary flow channels. Since the temperature of the condenser cover is lower than that of the evaporator cover, when the steam reaches the end of the capillary flow channels of the evaporator cover, it gradually condenses into micro-droplets at the end of the capillary flow channels of the condenser cover. Under the guidance of the capillary flow channels of the condenser cover, the micro-droplets gradually converge into liquid droplets in the collection area of the condenser cover. As the droplets grow larger, the height of the liquid column in the collection area of the condenser cover increases. When the liquid column contacts the collection area of the evaporator cover, a liquid bridge is formed. The liquid bridge allows the cooling medium in the collection area of the condenser cover to be transported to the collection area of the evaporator cover, preventing the evaporator cover from drying out. The cooling medium circulates back through the capillary flow channels, thereby improving the heat dissipation performance of the ultra-thin heat spreader.
[0008] As a preferred embodiment, each of the capillary flow channels is arranged in a Fibonacci spiral pattern, and the capillary flow channels overlap to form a golden spiral mesh structure. This golden spiral mesh structure is an existing technology. The arrangement of the golden spiral mesh structure can increase the space utilization rate, so that the inner surface of the evaporator cover and the condenser cover can accommodate a larger number of capillary flow channels, thereby improving the cooling effect.
[0009] As a preferred embodiment, the evaporator cover plate and the condenser cover plate are respectively provided with a collection groove at their collection areas. One end of each capillary flow groove is connected to each collection groove. The condensed cooling medium is collected in the collection groove of the condenser cover plate to form droplets, and the droplets are transported to the collection groove of the evaporator cover plate through a liquid bridge.
[0010] As a preferred embodiment, each of the collecting tanks is located at the center of the inner surface of the evaporation cover plate and the condensation cover plate. During operation, the cooling medium evaporates from the inner surface of the evaporation cover plate and diffuses from the center to the surrounding area. Subsequently, the cooling medium gradually condenses from the surrounding area of the condensation cover plate and gathers into droplets at the center of the inner surface of the condensation cover plate.
[0011] As a preferred embodiment, to facilitate the input of the cooling medium, the evaporation cover plate and / or the condensation cover plate are provided with a liquid injection port that communicates with the capillary flow channel. Before the cooling medium is input, the cavity is first evacuated.
[0012] As a preferred embodiment, the distance between the inner surface of the evaporation cover plate and the collection area of the condensation cover plate is 0.08-0.1 mm. At this distance, the droplets in the collection grooves of the evaporation cover plate and the condensation cover plate can form liquid bridges, which facilitates the transport of the cooling medium and makes the heat spreader plate have an ultra-thin shape, suitable for smartphones.
[0013] As a preferred embodiment, the inner surfaces of the evaporator cover plate and the condenser cover plate are respectively provided with superhydrophobic layers, and the capillary flow channels of the evaporator cover plate and the condenser cover plate are provided with superhydrophilic layers. By providing superhydrophobic and superhydrophilic layers, the cooling medium can be guided to flow along the capillary flow channels.
[0014] As a preferred embodiment, since the cooling medium expands in volume after evaporating to form steam, the volume ratio of the cooling medium in the cavity is 20-40%.
[0015] As a preferred embodiment, the narrow opening width of each microchannel is 0.25-0.58mm, the wide opening width of each microchannel is 0.65-0.93mm, and the length of each microchannel is 3.08-3.88mm.
[0016] To achieve the above objectives, this solution provides an electronic device including the aforementioned ultra-thin heat spreader and a heat-generating component within the electronic device, wherein the ultra-thin heat spreader is disposed within the electronic device and the evaporation cover faces the heat-generating component.
[0017] Compared with the prior art, the beneficial effects of this utility model are: 1. The ultra-thin heat spreader of this utility model uses an evaporation cover plate and a condensation cover plate for the evaporation and condensation of the cooling medium, respectively. Then, it uses a capillary flow channel composed of multiple microchannels connected in sequence to achieve the autonomous flow of the cooling medium. The flow efficiency of the cooling medium is improved by the overlapping of multiple capillary flow channels to form a golden spiral grid structure.
[0018] 2. By arranging multiple capillary channels in a Fibonacci spiral pattern and overlapping them to form a golden spiral grid structure, the maximum utilization of resources can be achieved in a limited space. This results in a better layout of capillary channels on the evaporator cover and the cooling cover, higher space utilization, and a thinner appearance for the ultra-thin heat spreader while ensuring heat dissipation performance.
[0019] 3. The ultra-thin heat spreader of this utility model has a collection groove in the collection area of the evaporation cover plate and the condensation cover plate. This allows the cooling medium droplets to evaporate at the collection groove of the evaporation cover plate and diffuse in all directions along the capillary flow groove of the evaporation cover plate. At the same time, the evaporated cooling medium condenses and flows along the capillary flow groove of the condensation cover plate to the collection groove to form droplets. Then, the droplets at the collection groove of the condensation cover plate are transported to the collection groove of the evaporation cover plate through the liquid bridge to realize the autonomous circulation of the cooling medium and improve the heat dissipation performance of the ultra-thin heat spreader.
[0020] 4. By setting a superhydrophobic layer on the inner surface of the evaporator cover plate and the condenser cover plate, the retention of cooling medium in the non-capillary flow channel area can be reduced. By setting a superhydrophilic layer on the capillary flow channel surface of the evaporator cover plate and the condenser cover plate, the cooling medium can be guided to flow along the capillary flow channel. Attached Figure Description
[0021] Figure 1 This is an exploded view of the ultra-thin heat spreader of this utility model; Figure 2 This is a schematic diagram of the evaporator cover plate. Figure 3 This is a schematic diagram of the condenser cover. Figure 4 This is a schematic diagram of the structure of a single capillary channel on the evaporator cover plate; Figure 5 This is a schematic diagram of the structure of a single capillary channel on the condenser cover plate; Figure 6 This is a schematic diagram showing the flow direction of the cooling medium in the capillary channel; Figure 7 This is a schematic diagram of the microchannels in a capillary flow channel; Figure 8 This is a graph showing the experimental results when the cooling medium accounts for 20% of the cavity volume. Figure 9 This is a graph showing the experimental results when the cooling medium accounts for 30% of the cavity volume. Figure 10 This is a graph showing the experimental results when the cooling medium accounts for 40% of the cavity volume.
[0022] In the diagram: 1. Evaporation cover plate; 2. Condensation cover plate; 3. Capillary flow channel; 31. Microchannel; 32. Collection channel; 4. Liquid injection port. Detailed Implementation
[0023] The accompanying drawings are for illustrative purposes only and should not be construed as limiting this patent. To better illustrate this embodiment, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings. The positional relationships described in the drawings are for illustrative purposes only and should not be construed as limiting this patent.
[0024] In the accompanying drawings of this utility model, the same or similar reference numerals correspond to the same or similar components. In the description of this utility model, it should be understood that if terms such as "upper," "lower," "left," "right," "long," and "short" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting this patent. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.
[0025] The technical solution of this utility model will be further described in detail below through specific embodiments and with reference to the accompanying drawings: Example 1: like Figure 1-7As shown, this embodiment provides an ultrathin heat spreader, characterized in that it includes a thermally conductive evaporator cover plate 1, a condenser cover plate 2, and a cooling medium. The evaporator cover plate 1 and the condenser cover plate 2 are fitted together and sealed, forming a cavity between them. The cooling medium is disposed in the cavity. The inner surfaces of the evaporator cover plate 1 and the condenser cover plate 2 are respectively provided with a network of grooves through which the cooling medium can flow. The network of grooves includes at least one converging area and several capillary channels 3 radiating outwards from the converging area. Each capillary channel 3 includes a microchannel 31 with a narrow opening at one end and a wide opening at the other end. The narrow and wide openings of several microchannels 31 are sequentially connected end-to-end. The evaporator cover plate 1 and the condenser cover plate 2... The groove network on plate 2 has a one-to-one correspondence with the collection area. The narrow opening of each microchannel 31 on the evaporator cover plate 1 faces the collection area of the evaporator cover plate 1. The narrow opening of the last stage microchannel 31 of each capillary flow groove 3 on the evaporator cover plate 1 is connected to the collection area on the evaporator cover plate 1. The wide opening of each microchannel 31 on the condenser cover plate 2 faces the collection area of the condenser cover plate 2. The wide opening of the last stage microchannel 31 of each capillary flow groove 3 on the condenser cover plate 2 is connected to the collection area on the condenser cover plate 2. The collection area on the condenser cover plate 2 collects the cooling medium to form a highly grown liquid column. The liquid column can be connected to the collection area on the evaporator cover plate 1 to establish a connected circulation relationship between the groove network on the evaporator cover plate 1 and the groove network on the condenser cover plate 2.
[0026] In this embodiment, the evaporation cover plate 1 and the condensation cover plate 2 are made of metal materials with high melting point, high oxidation resistance and high hardness.
[0027] In this embodiment, in the narrow and wide openings of the microchannel 31, the cooling medium droplets are subjected to the Laplace pressure difference and capillary force, and the cooling medium droplets will spontaneously flow from the narrow opening to the wide opening of the microchannel 31. By connecting multiple microchannels 31 end to end in sequence to form a capillary flow channel 3, the cooling medium droplets flow from the narrow opening of one microchannel 31 to the wide opening, and then flow into the narrow opening of the next microchannel 31, and so on, so that the cooling medium droplets can flow autonomously in the capillary flow channel 3. A collection area is provided at the center of the inner surface of the evaporation cover plate 1 and the condensation cover plate 2, so that the cooling medium can diffuse from the center of the evaporation cover plate 1 to the surrounding area, and then collect from the condensation cover plate 2 to the center.
[0028] In this embodiment, as Figure 7As shown, the narrow opening a, wide opening b, included angle c, and length d of microchannel 31 directly affect the magnitude of the Laplace pressure difference. A larger ratio of the wide opening to the narrow opening of microchannel 31 results in a greater difference in the radius of curvature, leading to a larger Laplace pressure difference. However, if the wide opening size b is too large, microdroplets may easily detach from it; if the narrow opening size a is too small, molecular dispersion may cause the Yang-Laplace equation to fail, affecting microdroplet transport. The included angle c of microchannel 31 also directly affects the Laplace pressure difference. When c is small, the curvature change of microchannel 31 is relatively gradual, resulting in a smaller Laplace pressure difference; when c is large, the curvature change of microchannel 31 is larger, leading to a larger Laplace pressure difference and more significant microdroplet acceleration. The size of the included angle c directly affects the rate of directional movement of the microdroplets. The length d of the microchannel 31 is also related to the movement distance of the microdroplets. If d is too long, it will increase the viscous resistance of the microdroplet flow, which is not conducive to the transport of the microdroplets. If d is too short, the microdroplets may stop transporting before reaching the wide opening. The narrow opening a, the wide opening b, the included angle c, and the length d of the microchannel 31 need to be within a suitable range to provide appropriate driving force. To comprehensively consider the Laplace pressure difference and the viscous resistance of the microdroplet flow, the narrow opening a of the microchannel 31 is in the range of 0.25-0.58 mm, the wide opening b is in the range of 0.65-0.93 mm, the angle c is in the range of 8-11°, and the length d is in the range of 3.08-3.88 mm, which can enable the microdroplets to flow stably.
[0029] Specifically, each of the capillary flow channels 3 is arranged in a Fibonacci spiral pattern, and each of the capillary flow channels 3 overlaps with each other to form a golden spiral grid structure.
[0030] In this embodiment, the multiple capillary channels 3 are arranged in a Fibonacci spiral and overlap each other to form a golden spiral grid structure, so that the capillary channels 3 are evenly distributed on the evaporation cover plate 1, which facilitates uniform heat diffusion.
[0031] Specifically, the evaporation cover plate 1 and the condensation cover plate 2 are respectively provided with a collection groove 32, and one end of each capillary flow groove 3 is connected to each collection groove 32.
[0032] In this embodiment, the collecting groove 32 is a circular structure, and each collecting groove 32 is respectively located at the center of the inner surface of the evaporation cover plate 1 and the condensation cover plate 2.
[0033] In this embodiment, the golden spiral mesh structure is composed of multiple Fibonacci spirals arranged in a circular array and overlapping each other along the convergence area. The Fibonacci spiral is formed by the Fibonacci sequence and the golden ratio. Each spiral unit has the same proportion as the overall spiral, meaning that any part of this spiral, when magnified, resembles the overall spiral shape. Furthermore, the radii of adjacent spirals increase according to the golden ratio. Such a structure is typically found in nature, such as the seeds in a sunflower head. This structure maximizes resource utilization within a limited space. Therefore, the layout of the golden spiral mesh structure can increase the utilization rate of the space within the ultra-thin heat spreader. Secondly, the curve shape of the Fibonacci spiral structure is continuous and uniformly varied. This feature can guide the cooling medium microdroplets to converge or disperse through the spiral path of the capillary flow channel 3. From a fluid dynamics perspective, this can reduce the kinetic energy loss of the microdroplets along the path and improve the collection and dispersion efficiency.
[0034] Specifically, the evaporation cover plate 1 and / or the condensation cover plate 2 are provided with a liquid injection port 4 that communicates with the capillary flow channel 3.
[0035] Specifically, the distance between the inner surface of the evaporation cover plate 1 and the collection area of the condensation cover plate 2 is 0.08-0.1 mm.
[0036] Specifically, the cooling medium accounts for 20-40% of the volume of the cavity.
[0037] In this embodiment, 18 temperature measuring points were arranged on the heat spreader, and a temperature analysis experiment was conducted using the controlled variable method. The variable was the volume ratio of the cooling medium in the cavity, with experiments conducted at 20%, 30%, and 40% respectively. The experimental results are as follows. Figure 8-10 It can be seen that the cooling effect is best when the volume ratio of the cooling medium in the cavity is 20%. Therefore, the volume ratio of the cooling medium in the cavity can be preferably 20%.
[0038] Specifically, the cooling medium is any one of water, ethanol, acetone, or hexamethyldisiloxane solution.
[0039] Example 2: This embodiment is similar to Embodiment 1, except that in this embodiment, the inner surfaces of the evaporation cover plate 1 and the condensation cover plate 2 are respectively provided with superhydrophobic layers, and the capillary flow grooves 3 of the evaporation cover plate 1 and the condensation cover plate 2 are provided with superhydrophilic layers.
[0040] In this embodiment, the manufacturing process of the superhydrophobic layer and superhydrophilic layer of the evaporation cover plate 1 and the condensation cover plate 2 is as follows: First, the inner surfaces of the evaporation cover plate 1 and the condensation cover plate 2 are immersed in a solution, coated with titanium dioxide, and then irradiated with ultraviolet light to make the inner surfaces of the evaporation cover plate 1 and the condensation cover plate 2 hydrophilic. The hydrophilic inner surfaces are then treated with a hydrophobic coating by spin coating with a hydrophobic solution. Finally, the inner surfaces are cured at high temperature in an oven to form a dense hydrophobic surface layer. The hydrophobic solution is a homogeneous solution formed by dissolving polyvinylidene fluoride powder and fluorosilane in N-methylpyrrolidone solvent and stirring, so that a superhydrophobic layer is formed on the inner surfaces of the evaporation cover plate 1 and the condensation cover plate 2. The hydrophobic coating on the surface of the capillary flow channel 3 and the collecting channel 32 is removed by laser treatment to expose the underlying hydrophilic surface. The hydrophilicity of the patterned part is activated by short-term ultraviolet irradiation, thereby forming a superhydrophilic layer on the surface of the capillary flow channel 3 and the collecting channel 32.
[0041] Example 3: This embodiment provides an electronic device, including the aforementioned ultra-thin heat spreader and a heat-generating component within the electronic device. The ultra-thin heat spreader is disposed within the electronic device, and the evaporation cover 1 faces the heat-generating component.
[0042] In this embodiment, the heat generated by the heating element is absorbed by the evaporation cover plate 1, causing the cooling medium to absorb heat and evaporate, and then condense into droplets on the condensation cover plate 2. This operation will be repeated in the cavity to achieve heat dissipation.
[0043] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.
[0044] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating this utility model, and are not intended to limit the implementation of this utility model. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.
Claims
1. An ultrathin heat spreader, characterized in that, The system includes a heat-conducting evaporator cover plate (1), a condenser cover plate (2), and a cooling medium. The evaporator cover plate (1) and the condenser cover plate (2) are fitted together and sealed. A cavity is formed between the evaporator cover plate (1) and the condenser cover plate (2). The cooling medium is disposed in the cavity. The inner surfaces of the evaporator cover plate (1) and the condenser cover plate (2) are respectively provided with a network of grooves through which the cooling medium can flow. The network of grooves includes at least one converging area and several capillary channels (3) radiating outward from the converging area. Each capillary channel (3) includes a microchannel (31) with a narrow opening at one end and a wide opening at the other end. The narrow and wide openings of several microchannels (31) are connected end to end. The converging areas of the network of grooves on the evaporator cover plate (1) and the condenser cover plate (2) correspond one-to-one. The narrow openings of each microchannel (31) face the collection area of the evaporation cover plate (1). The narrow opening of the last stage microchannel (31) of each capillary flow groove (3) on the evaporation cover plate (1) is connected to the collection area on the evaporation cover plate (1). The wide openings of each microchannel (31) on the condensation cover plate (2) face the collection area of the condensation cover plate (2). The wide opening of the last stage microchannel (31) of each capillary flow groove (3) on the condensation cover plate (2) is connected to the collection area on the condensation cover plate (2). The collection area on the condensation cover plate (2) collects the cooling medium to form a highly grown liquid column. The liquid column can be connected to the collection area on the evaporation cover plate (1) to establish a connected circulation relationship between the groove network on the evaporation cover plate (1) and the groove network on the condensation cover plate (2). The volume ratio of the cooling medium in the cavity is 10-70%.
2. The ultrathin heat spreader according to claim 1, characterized in that, Each of the capillary flow grooves (3) is arranged in a Fibonacci spiral, and each of the capillary flow grooves (3) overlaps with each other to form a golden spiral grid structure.
3. The ultrathin heat spreader according to claim 2, characterized in that, The evaporation cover plate (1) and the condensation cover plate (2) are respectively provided with a collection groove (32), and one end of each capillary flow groove (3) is connected to each collection groove (32).
4. The ultrathin heat spreader according to claim 3, characterized in that, Each of the collection tanks (32) is located at the center of the inner surface of the evaporation cover plate (1) and the condensation cover plate (2).
5. The ultrathin heat spreader according to claim 1, characterized in that, The evaporation cover plate (1) and / or the condensation cover plate (2) are provided with a liquid injection port (4) communicating with the cavity.
6. The ultrathin heat spreader according to claim 1, characterized in that, The distance between the collection area of the evaporation cover plate (1) and the collection area of the condensation cover plate (2) is 0.08-0.1 mm.
7. An ultrathin heat spreader according to any one of claims 1-6, characterized in that, The inner surfaces of the evaporation cover plate (1) and the condensation cover plate (2) are respectively provided with superhydrophobic layers, and the capillary flow grooves (3) of the evaporation cover plate (1) and the condensation cover plate (2) are provided with superhydrophilic layers.
8. The ultrathin heat spreader according to claim 1, characterized in that, The cooling medium accounts for 20-40% of the volume of the cavity.
9. The ultrathin heat spreader according to claim 1, characterized in that, The narrow opening width of each microchannel (31) is 0.25-0.58mm, the wide opening width of each microchannel (31) is 0.65-0.93mm, and the length of each microchannel (31) is 3.08-3.88mm.
10. An electronic device, characterized in that, Includes the ultra-thin heat spreader as described in any one of claims 1-9 and the heat-generating components within the electronic device, wherein the ultra-thin heat spreader is disposed within the electronic device and the evaporation cover (1) faces the heat-generating components.