Graphene-based phase change vapor chamber

Abstract

The invention provides a graphene-based phase-change vapor chamber. The graphene-based phase-change vapor chamber comprises a shell and a plurality of fins, the shell is provided with a cavity, and the cavity is filled with phase change wax; the fins are arranged in the cavity and vertically arranged relative to the bottom plate of the shell, the bottom edges of the fins make contact with the bottom wall of the cavity, the top edges of the fins make contact with the top wall of the cavity, and the multiple fins are arranged at intervals in the first direction parallel to the bottom plate; the fin comprises at least one layer of graphene film, two layers of metal plates and at least two layers of alloy material layers, the two layers of metal plates are located on the two sides of the graphene film in the first direction respectively, the alloy material layers are arranged between every two adjacent layers of graphene films and between the graphene film and the metal plates respectively, the material melting point of each alloy material layer is 150-300 DEG C, and the material melting point of each alloy material layer is 150-300 DEG C. The multi-layer structure of the fin is packaged on the edge to form a composite packaging structure.

Description

Technical Field

[0001] This disclosure relates to the field of heat exchanger technology, and more particularly to a graphene-based phase change heat exchanger. Background Technology

[0002] As the working environment and installation space requirements of radar jamming equipment on ballistic and airborne military platforms become increasingly demanding, the integration level becomes higher, and the transmission power requirements become greater, the heat flux density of the equipment increases dramatically, and the requirements for the equipment's heat dissipation capacity also rise sharply.

[0003] To meet the rapidly growing demand for heat dissipation, existing solutions employ a composite heat dissipation design based on phase change materials and vapor chambers. However, these traditional phase change vapor chambers are encapsulated by a certain volume of wax within a metal shell with arranged cylindrical heat dissipation fins. While they possess some phase change energy storage and heat conduction capabilities, the equivalent heat conduction is relatively low due to the combination of aluminum and phase change materials for longitudinal heat conduction, making it difficult to meet the ever-increasing heat dissipation requirements. Summary of the Invention

[0004] A primary objective of this disclosure is to overcome at least one of the deficiencies of the prior art and to provide a graphene-based phase change heat exchanger with better heat dissipation and a simpler structure.

[0005] To achieve the above objectives, the present disclosure adopts the following technical solution:

[0006] According to one aspect of this disclosure, a graphene-based phase change heat spreader is provided, comprising a shell and a plurality of fins; the shell has a cavity filled with phase change wax; the fins are disposed in the cavity and arranged perpendicularly to the bottom plate of the shell, the bottom edge of the fins contacting the bottom wall of the cavity, the top edge of the fins contacting the top wall of the cavity, and the plurality of fins are spaced apart along a first direction parallel to the bottom plate; the fins comprise at least one graphene film, two metal plates, and at least two alloy material layers, the two metal plates being located on opposite sides of the graphene film in the first direction, and the alloy material layers being disposed between adjacent graphene film layers and between the graphene film and the metal plates, the alloy material layers having a melting point of 150°C to 300°C, and the multilayer structure of the fins being encapsulated at the edges to form a composite encapsulation structure.

[0007] According to one embodiment of this disclosure, the alloy material layer is a eutectic alloy comprising one or at least two of bismuth, tin, lead, and indium; and / or, the metal plate is made of aluminum.

[0008] According to one embodiment of this disclosure, the thickness of the graphene film is 40 μm to 70 μm; and / or the thickness of the metal plate is greater than or equal to 800 μm; and / or the thickness of the alloy material layer is 1 μm to 5 μm.

[0009] According to one embodiment of the present disclosure, the fin has a first gap between its side edge in the second direction and the side wall of the cavity in the second direction.

[0010] According to one embodiment of this disclosure, the width of the first gap is 2 mm to 4 mm.

[0011] According to one embodiment of this disclosure, the graphene-based phase change heat spreader further includes a connecting assembly that can fix the plurality of fins to the housing along the first direction; the connecting assembly includes a plurality of connecting ribs spaced apart along the first direction, the connecting ribs connecting between two adjacent fins, or connecting between the fins located at the ends in the first direction and the sidewall of the cavity in the first direction.

[0012] According to one embodiment of this disclosure, the height of the connecting rib is less than the height of the fin, so that the bottom of the connecting rib has a second gap with the bottom wall of the cavity, and / or, so that the top of the connecting rib has a third gap with the top wall of the cavity.

[0013] According to one embodiment of this disclosure, a plurality of the fins are arranged at equal intervals along the first direction.

[0014] According to one embodiment of this disclosure, the housing has a protrusion at one apex of the cavity, the protrusion has a through hole that connects the cavity to the outside of the housing, and the through hole can serve as a vacuum hole for evacuating the cavity and an injection hole for injecting phase change wax into the cavity.

[0015] According to one embodiment of this disclosure, the housing includes a body and a cover plate. The body includes a bottom plate and a side plate disposed on the edge of the bottom plate. The cover plate is disposed at the opening of the body, and the body and the cover plate together form the cavity.

[0016] As can be seen from the above technical solution, the advantages and positive effects of the graphene-based phase change heat spreader proposed in this disclosure are as follows:

[0017] The graphene-based phase change heat spreader disclosed herein includes a shell and multiple fins; the shell has a cavity filled with phase change wax; the fins are disposed in the cavity and arranged perpendicularly to the bottom plate of the shell, the bottom edge of the fins contacts the bottom wall of the cavity, the top edge of the fins contacts the top wall of the cavity, and the multiple fins are spaced apart along a first direction parallel to the bottom plate; the fins include at least one graphene film, two metal plates and at least two alloy material layers, the two metal plates are respectively located on both sides of the graphene film in the first direction, and two alloy material layers are respectively disposed between two adjacent graphene films and between the graphene film and the metal plates, the melting point of the alloy material layers is 150℃~300℃, and the multi-layer structure of the fins is encapsulated at the edges to form a composite encapsulation structure. Through the above design, this disclosure employs a special composite encapsulation design for the fin structure. Specifically, it uses a graphene film, an alloy material layer, and a metal plate to form a composite encapsulation structure for the fins. The alloy material layer is used to achieve structural connection between the metal plate and the graphene film, enabling adhesion and orientation of the graphene film. This fully utilizes the high in-plane thermal conductivity of the graphene film, i.e., its high thermal conductivity in the lateral and perpendicular directions to the base plate, to improve the longitudinal thermal conductivity of the phase change heat exchanger. Simultaneously, because the alloy material layer used for the fins has a low melting point and remains liquid during the operation of the heat-generating equipment, it possesses a certain enthalpy value, thereby improving the overall energy storage capacity of the phase change heat exchanger. Attached Figure Description

[0018] The various objectives, features, and advantages of this disclosure will become more apparent from the following detailed description of preferred embodiments of the disclosure taken in conjunction with the accompanying drawings. The drawings are merely illustrative illustrations of the disclosure and are not necessarily drawn to scale. In the drawings, the same reference numerals always denote the same or similar parts. Wherein:

[0019] Figure 1 This is a three-dimensional exploded view of a graphene-based phase change heat spreader according to an exemplary embodiment.

[0020] Figure 2 This is a three-dimensional structural diagram of a combination structure of multiple fins and connecting components;

[0021] Figure 3 This is a partially enlarged schematic diagram of the three-dimensional exploded structure of the fin;

[0022] Figure 4 yes Figure 1 A schematic diagram showing the temperature change curves of the graphene-based phase change heat spreader and a comparative embodiment.

[0023] Figure 5 yes Figure 1 The diagram shows a simulation of a graphene-based phase change heat spreader and a comparative embodiment.

[0024] The annotations in the attached figures are explained as follows:

[0025] 100. Shell;

[0026] 101. Cavity;

[0027] 110. Ontology;

[0028] 111. Base plate;

[0029] 112. Side panels;

[0030] 113. Bump;

[0031] 114. Through hole;

[0032] 120. Cover plate;

[0033] 200. Fins;

[0034] 210. Graphene film;

[0035] 220. Alloy material layer;

[0036] 230. Metal plate;

[0037] 310. Connecting ribs;

[0038] X. First direction;

[0039] Y. Second direction. Detailed Implementation

[0040] Typical embodiments embodying the features and advantages of this disclosure will be described in detail in the following description. It should be understood that this disclosure can have various variations in different embodiments without departing from the scope of this disclosure, and the descriptions and drawings therein are illustrative in nature and not intended to limit this disclosure.

[0041] In the following description of various exemplary embodiments of this disclosure, reference is made to the accompanying drawings, which form part of this disclosure, and which illustrate by way of example different exemplary structures, systems, and steps that can implement various aspects of this disclosure. It should be understood that other specific embodiments of the components, structures, exemplary devices, systems, and steps may be used, and structural and functional modifications may be made without departing from the scope of this disclosure. Furthermore, while the terms “above,” “between,” “within,” etc., may be used in this specification to describe different exemplary features and elements of this disclosure, these terms are used herein only for convenience, such as the orientation according to the examples described in the accompanying drawings. Nothing in this specification should be construed as requiring a specific three-dimensional orientation of the structure to fall within the scope of this disclosure.

[0042] See Figure 1The illustration shows a representative three-dimensional exploded view of the graphene-based phase change vapor chamber proposed in this disclosure. In this exemplary embodiment, the graphene-based phase change vapor chamber proposed in this disclosure is described as a heat dissipation device applied to radar jamming equipment. It will be readily understood by those skilled in the art that various modifications, additions, substitutions, deletions, or other changes may be made to the specific embodiments described below in order to apply the relevant designs of this disclosure to other types of heat dissipation application scenarios, and these changes are still within the scope of the principles of the graphene-based phase change vapor chamber proposed in this disclosure.

[0043] like Figure 1 As shown, in one embodiment of this disclosure, the graphene-based phase change heat spreader includes a shell 100 and a plurality of fins 200. (See also...) Figures 2 to 5 , Figure 2 The diagram shows a three-dimensional structural schematic of a combination structure of multiple fins 200 and connecting components. Figure 3 The diagram shows a partially enlarged view of the three-dimensional exploded structure of fin 200; Figure 4 China representatively shows Figure 1 A schematic diagram showing the temperature change curves of the graphene-based phase change heat spreader and a comparative embodiment. Figure 5 China representatively shows Figure 1 The diagram shows a simulation illustration of a graphene-based phase change vapor chamber and a comparative embodiment. The structure, connection method, and functional relationship of the main components of the graphene-based phase change vapor chamber proposed in this disclosure will be described in detail below with reference to the above-mentioned figures.

[0044] like Figures 1 to 3As shown, in one embodiment of this disclosure, the housing 100 has a cavity 101 filled with phase change wax. Fins 200 are disposed in the cavity 101, arranged perpendicularly to the bottom plate 111 of the housing 100. The bottom edge of the fins 200 contacts the bottom wall of the cavity 101, and the top edge of the fins 200 contacts the top wall of the cavity 101, thereby achieving longitudinal (i.e., perpendicular to the bottom plate 111) heat conduction. Multiple fins 200 are arranged at intervals along a first direction X parallel to the bottom plate 111. Each fin 200 includes a graphene film 210, two metal plates 230, and two alloy material layers 220. Specifically, the two metal plates 230 are located on opposite sides of the graphene film 210 in the first direction X. The two metal plates 230 can form a central cavity within the fin 200 to accommodate the multilayer structure composed of the alloy material layer 220 and the graphene film 210. Two alloy material layers 220 are respectively disposed between the graphene film 210 and the two metal plates 230. The alloy material layers 220 can be used as an adhesive layer, for example, by applying a primer to achieve the bonding connection between the graphene film 210 and the metal plates 230. The melting point of the alloy material layers 220 is 150℃~300℃, for example, 150℃, 180℃, 200℃, 250℃, 300℃, etc. The multi-layer structure of the fins 200 (i.e., the graphene film 210, the two metal plates 230 and the two alloy material layers 220) is encapsulated at the edges to form a composite encapsulation structure. Accordingly, the alloy material layers 220 can provide three functions: bonding function, filling gaps and voids to reduce interfacial thermal resistance, and improving energy storage capacity through the solid-liquid conversion of the metal material. Through the above design, this disclosure adopts a special composite packaging design for the structure of fin 200. Specifically, a composite packaging structure of fin 200 is composed of graphene film 210, alloy material layer 220 and metal plate 230. Specifically, the alloy material layer 220 is used to realize the structural connection between metal plate 230 and graphene film 210, realizing the adhesion and orientation of graphene film 210. In this way, the high in-plane thermal conductivity of graphene film 210, that is, the high thermal conductivity in the transverse direction (e.g., the second direction Y) and the direction perpendicular to the base plate 111 (e.g., the thermal conductivity of graphene film 210 can reach 1500W / mK, and the limiting thermal conductivity can reach 5300W / mK), is fully utilized to improve the longitudinal thermal conductivity of phase change heat spreader (e.g., the direction perpendicular to the base plate 111), thereby improving the overall inter-surface thermal conductivity of phase change heat spreader. Meanwhile, since the alloy material layer 220 used in the fin 200 has a low melting point and can be in a liquid state when the heat-generating equipment is working, it has a certain enthalpy value, which will increase the overall enthalpy value of the phase change heat exchanger to a certain extent, thereby improving the overall energy storage capacity of the phase change heat exchanger. In addition, the liquid alloy material can also achieve the function of filling gaps through its fluidity, better realize the connection between the graphene film 210 and the metal plate 230, and reduce the interfacial thermal resistance.

[0045] See also Figure 4 and Figure 5 , Figure 4 This is a schematic diagram of the temperature (heat source temperature) change curves of the graphene-based phase change vapor chamber proposed in this disclosure and a comparative embodiment. Figure 5 This is a simulation diagram of the graphene-based phase change heat spreader proposed in this disclosure and a comparative embodiment. The comparative embodiment shown in the diagram refers to a design where the fins do not contain an encapsulated graphene film, and all other designs are identical to those in this disclosure. Figure 4 In the diagram, the black curve represents the temperature change curve of this disclosure, and the red curve represents the change curve of the comparative embodiment. Therefore, it can be seen that, compared to the comparative embodiment, this disclosure has a certain advantage in reducing the temperature rise of the heat source. Figure 5 In the diagram, the two simulation graphs on the left are simulation graphs of temperature uniformity at two time points of 700s and 1200s for the comparative embodiment, and the two simulation graphs on the right are simulation graphs of temperature uniformity at two time points of 700s and 1200s for the present disclosure. It can be seen that, compared with the comparative embodiment, the present disclosure has certain advantages in improving the temperature uniformity of the phase change structure.

[0046] It should be noted that, Figure 3 The illustrated embodiment uses a fin 200 comprising one graphene film 210 and two alloy material layers 220 as an example. In this case, the alloy material layers 220 are only disposed between the graphene film 210 and the metal plate 230. It should be understood that in other embodiments of this disclosure, the fin 200 may also include two or more graphene films 210 and three or more alloy material layers 220, for example, specifically including three graphene films 210 and four alloy material layers 220. In this case, in addition to the space 230 between the graphene films 210 and the metal plate, alloy material layers 220 are also disposed between adjacent graphene films 210. Accordingly, in various possible embodiments conforming to the design concept of this disclosure, the fin 200 may include at least one graphene film 210, two metal plates 230 and at least two alloy material layers 220, wherein the number of graphene film 210 layers and the number of alloy material layers 220 layers can be flexibly selected according to the thickness requirements of the fin 200, and the number of alloy material layers 220 layers is one more than the number of graphene film 210 layers.

[0047] In one embodiment of this disclosure, the graphene film may be a reduced graphene oxide film.

[0048] In one embodiment of this disclosure, the alloy material layer 220 may be a eutectic low-melting-point alloy comprising one or at least two of bismuth (Bi), tin (Sn), lead (Pb), and indium (In). Through the above design, because such materials have low melting points, this disclosure ensures that the melting point of the alloy material layer 220 meets the design requirement of 150°C to 300°C.

[0049] In one embodiment of this disclosure, the metal plate 230 may be made of aluminum (Al). Through the above design, due to the density of aluminum, this disclosure can reduce the weight of the fins 200, further meeting the requirements for lightweighting.

[0050] In one embodiment of this disclosure, the thickness of the graphene film 210 (i.e., the thickness of the graphene film 210 in the first direction X) can be 40 μm to 70 μm, for example, 40 μm, 45 μm, 50 μm, 60 μm, 70 μm, etc. Through the above design, this disclosure avoids the problem of insufficient heat dissipation performance due to an excessively thin graphene film 210, while also avoiding the problem of poor interfacial bonding caused by an excessively thick graphene film 210.

[0051] In one embodiment of this disclosure, the thickness of the metal plate 230 (i.e., the thickness of the metal plate 230 in the first direction X) can be greater than or equal to 800 μm (i.e., 0.8 mm), for example, 800 μm, 850 μm, 900 μm, 1000 μm, etc. Through the above design, this disclosure can avoid the metal plate 230 being too thin, thereby ensuring that the fin 200 has sufficient thickness, that is, ensuring that the fin 200 has a certain structural strength. Accordingly, when the bottom edge of the fin 200 contacts the bottom wall of the cavity 101 and the top edge of the fin 200 contacts the top wall of the cavity 101, this disclosure can use the fin 200 as a support column, further improving the structural strength of the phase change heat spreader.

[0052] In one embodiment of this disclosure, the thickness of the alloy material layer 220 can be 1 μm to 5 μm, such as 1 μm, 1.5 μm, 2 μm, 3 μm, 5 μm, etc. Through the above design, this disclosure can avoid the alloy material layer 220 being too thin, which would make its energy storage performance and its bonding and orientation effect on the graphene film 210 difficult to meet the requirements. At the same time, it can avoid the alloy material layer 220 being too thick, which would make the fin 200 too thick and cause material waste.

[0053] In one embodiment of this disclosure, the multilayer structure of the fin 200 can be encapsulated at the edges by a vacuum brazing process or an atomic diffusion bonding process.

[0054] In one embodiment of this disclosure, the solder material for the vacuum brazing process, based on the design of the fin 200 using vacuum brazing, can be a eutectic system including aluminum-silicon alloy or aluminum-silicon-chromium alloy. The melting temperature of such materials is 500°C–600°C, the brazing temperature is 530°C–630°C, and the welding vacuum degree is 10. -3 Pa~10 -2 Pa.

[0055] Based on the design of the fin 200 being packaged using a vacuum brazing process, in one embodiment of this disclosure, the protective gas for the vacuum brazing process can be one or a combination of argon (Ar) and nitrogen (N2), and the purity of the nitrogen can be greater than 99.99%.

[0056] In one embodiment of this disclosure, a first gap may be formed between the side edge of the fin 200 in the second direction Y and the side wall of the cavity 101 in the second direction Y, that is, the length of the fin 200 in the second direction Y may be less than the width of the cavity 101 in the second direction Y. Through the above design, this disclosure can utilize the aforementioned first gap to allow the phase change wax injected into the cavity 101 to flow, thereby ensuring that the phase change wax can flow sufficiently to all positions of the cavity 101 without being blocked by the fin 200, allowing the phase change wax to flow and diffuse throughout the cavity 101, ensuring the filling effect of the phase change wax.

[0057] Based on the design of a first gap between the side of the fin 200 and the side wall of the cavity 101, in one embodiment of this disclosure, the width of the first gap can be 2mm to 4mm, for example, 2mm, 2.5mm, 3mm, 4mm, or 5mm. Through this design, this disclosure can avoid the first gap being too narrow, which would affect the flow of phase change wax through the first gap, and at the same time, it can avoid the first gap being too wide, which would affect the size of the fin 200, ensuring that this disclosure achieves better heat dissipation performance under the premise that the size of the housing 100 is fixed.

[0058] like Figure 1 and Figure 2 As shown, in one embodiment of this disclosure, the graphene-based phase change heat spreader may further include a connecting assembly that can fix multiple fins 200 to the housing 100 along a first direction X. Specifically, the connecting assembly includes multiple connecting ribs 310 spaced apart along the first direction X. These connecting ribs 310 connect adjacent fins 200, or connect the fins 200 located at their ends in the first direction X to the sidewall of the cavity 101 in the first direction X. Through the above design, this disclosure can achieve mutual fixation of multiple fins 200 and mutual fixation of multiple fins 200 to the housing 100 using a connecting assembly including multiple connecting ribs 310, resulting in a simple structure and reliable connection.

[0059] Based on the design of the connecting components, in one embodiment of this disclosure, the height of the connecting rib 310 can be less than the height of the fin 200, so that the bottom of the connecting rib 310 has a second gap with the bottom wall of the cavity 101, and the top of the connecting rib 310 has a third gap with the top wall of the cavity 101. Through the above design, this disclosure can utilize the aforementioned second and third gaps to allow the phase change wax injected into the cavity 101 to flow, thereby ensuring that the phase change wax can flow sufficiently to all positions of the cavity 101 without being blocked by the connecting rib 310, allowing the phase change wax to flow and diffuse throughout the cavity 101, ensuring the filling effect of the phase change wax. In some embodiments, only one of the aforementioned second and third gaps may be provided; in other words, one of the top and bottom of the connecting rib 310 may also contact the cavity wall (top wall or bottom wall) of the cavity 101, and this is not limited to this embodiment.

[0060] like Figure 2 As shown, based on the design of the connecting components, in one embodiment of this disclosure, the graphene-based phase change heat spreader proposed in this disclosure may include at least two connecting components, such as, but not limited to, the two connecting components shown in the figure. The at least two connecting components are arranged at intervals along the second direction Y. Through the above design, this disclosure can further improve the connection and fixing strength between the plurality of fins 200 and between the plurality of fins 200 and the shell 100, further improving the structural determinism. In some embodiments, the graphene-based phase change heat spreader proposed in this disclosure may also include only one connecting component, and is not limited to this embodiment.

[0061] In one embodiment of this disclosure, the bottom edge of the fin 200 and the bottom wall of the cavity 101 can be connected by welding, specifically by vacuum brazing.

[0062] In one embodiment of this disclosure, the top edge of the fin 200 and the top wall of the cavity 101 (e.g., the inner wall of the cover plate 120) can be welded together, specifically by vacuum brazing.

[0063] Based on the design of connecting the fins 200 and the cavity wall of the cavity 101 using a vacuum brazing process, in one embodiment of this disclosure, the material of the solder used in the vacuum brazing process can be a eutectic system including aluminum-silicon alloy or aluminum-silicon-chromium alloy. The melting temperature of such materials is 500℃~600℃, the brazing temperature is 530℃~630℃, and the welding vacuum degree is 10. -3 Pa~10 - 2 Pa.

[0064] Based on the design of connecting the fins 200 and the cavity wall of the cavity 101 using a vacuum brazing process, in one embodiment of this disclosure, the protective gas for the vacuum brazing process can be either argon or nitrogen, or a combination of both, and the purity of the nitrogen can be greater than 99.99%.

[0065] In one embodiment of this disclosure, multiple fins 200 can be arranged at equal intervals along a first direction X. Through the above design, this disclosure can improve structural rationality, simplify the manufacturing process, and when adjacent fins 200 are fixedly connected by connecting ribs 310 of connecting components, each connecting rib 310 can be made to have the same structure, which is convenient for mass production, helps to reduce assembly difficulty, and improves assembly efficiency.

[0066] like Figure 1 As shown, in one embodiment of this disclosure, the housing 100 has a protrusion 113 at a apex of the cavity 101. The protrusion 113 has a through hole 114 that connects the cavity 101 to the outside of the housing 100. Accordingly, the through hole 114 can serve as a vacuum port for evacuating the cavity 101 and an injection port for injecting phase change wax into the cavity 101. Through this design, this disclosure utilizes the through hole 114 simultaneously as both a vacuum port and an injection port, which helps to reduce structural complexity.

[0067] Based on the design of the protrusion 113 on the housing 100, in one embodiment of this disclosure, taking a plane parallel to the base plate 111 as a reference plane, the proportion of the area of ​​the orthographic projection of the protrusion 113 in the area of ​​the orthographic projection of the base plate 111 on this reference plane can be less than or equal to 5‰, for example, 2‰, 2.5‰, 3‰, 4‰, 5‰, etc. Through the above design, this disclosure can avoid the protrusion 113 being too large and occupying too much space in the cavity 101, thereby reducing the size of the fins 200 that are reduced to avoid the protrusion 113, which is conducive to achieving a better heat dissipation effect.

[0068] Based on the design of the shell 100 having a protrusion 113 and a through hole 114, in one embodiment of this disclosure, the through hole 114 can extend along the first direction X. With this design, when the through hole 114 serves as an injection hole, it ensures that the phase change wax is injected along the first direction X when entering the cavity 101 through the through hole 114. Since there is a first gap between the side of the fin 200 and the side wall of the cavity 101, the phase change wax injected along the first direction X can quickly flow through each of the first gaps to various positions in the cavity 101 along the first direction X, further improving the injection efficiency of the phase change wax and ensuring that the cavity 101 is filled.

[0069] like Figure 1As shown, in one embodiment of this disclosure, the housing 100 may include a body 110 and a cover plate 120. The body 110 includes a bottom plate 111 and side plates 112 disposed on the edge of the bottom plate 111. The side of each side plate 112 away from the bottom plate 111 forms an opening. The cover plate 120 is disposed at the opening of the body 110. The body 110 and the cover plate 120 together form a cavity 101.

[0070] Based on the design of the housing 100 including the body 110 and the cover plate 120, in one embodiment of this disclosure, the cover plate 120 and the opening of the housing 100 can be connected by welding, specifically by vacuum brazing.

[0071] Based on the design of connecting the cover plate 120 and the housing 100 using a vacuum brazing process, in one embodiment of this disclosure, the material of the solder used in the vacuum brazing process can be a eutectic system including aluminum-silicon alloy or aluminum-silicon-chromium alloy. The melting temperature of such materials is 500℃~600℃, the brazing temperature is 530℃~630℃, and the welding vacuum degree is 10. -3 Pa~10 -2 Pa.

[0072] Based on the design of connecting the cover plate 120 and the housing 100 using a vacuum brazing process, in one embodiment of this disclosure, the protective gas for the vacuum brazing process can be either argon or nitrogen, or a combination of both, and the purity of the nitrogen can be greater than 99.99%.

[0073] In one embodiment of this disclosure, the phase change wax material may be one of n-tetradecane, n-pentadecanane, n-hexadecane, n-heptadecane, n-octadecane, or a combination of at least two of them.

[0074] Based on the detailed description of several exemplary embodiments of the graphene-based phase change heat spreader proposed in this disclosure above, the following will provide an exemplary description of one preparation process of the graphene-based phase change heat spreader:

[0075] Step S1: Hot-press or stamping to form a rectangular aluminum plate cavity with an internal cavity and an open top, i.e., the body 110 made of aluminum.

[0076] Step S2: A multi-layer structure is formed by stacking metal plate 230, alloy material layer 220, graphene film 210, alloy material layer 220 and metal plate 230 in sequence, and the multi-layer structure is encapsulated on the periphery by vacuum brazing to form a fin 200 with a composite encapsulation structure.

[0077] Step S3: Multiple fins 200 prepared in step S2 are arranged in the rectangular aluminum plate cavity prepared in step S1. The multiple fins 200 are arranged at intervals in the first direction X. The fins 200 are arranged vertically. The height of the fins 200 is equal to that of the cavity 101 and a first gap is left between the fins 200 and the side wall of the cavity 101 in the second direction Y.

[0078] Step S4: Arrange the multiple fins 200 from step S3 at equal intervals using a connecting assembly including connecting ribs 310 and fix them by vacuum brazing.

[0079] Step S5: The cover plate 120 is welded and fixed to the rectangular aluminum plate cavity by vacuum brazing, thereby forming a shell 100 with cavity 101.

[0080] Step S6: Vacuum the cavity 101 of the shell 100 prepared in step S5, inject phase change wax, and encapsulate to obtain a graphene-based phase change heat spreader.

[0081] It should be noted that the graphene-based phase change vapor chambers shown in the accompanying drawings and described in this specification are merely a few examples among many phase change vapor chambers capable of employing the principles of this disclosure. It should be clearly understood that the principles of this disclosure are by no means limited to any detail or component of the graphene-based phase change vapor chambers shown in the accompanying drawings or described in this specification.

[0082] In summary, the graphene-based phase change heat spreader proposed in this disclosure includes a shell 100 and a plurality of fins 200; the shell 100 has a cavity 101 filled with phase change wax; the fins 200 are disposed in the cavity 101 and arranged perpendicularly to the bottom plate 111 of the shell 100, the bottom edge of the fins 200 contacts the bottom wall of the cavity 101, the top edge of the fins 200 contacts the top wall of the cavity 101, and the plurality of fins 200 are arranged at intervals along a first direction X parallel to the bottom plate 111; 200 includes at least one graphene film 210, two metal plates 230 and at least two alloy material layers 220. The two metal plates 230 are respectively located on both sides of the graphene film 210 in the first direction X. The alloy material layers 220 are respectively disposed between two adjacent graphene films 210 and between the graphene film 210 and the metal plates 230. The melting point of the alloy material layers 220 is 150℃~300℃. The multi-layer structure of the fin 200 is encapsulated at the edge to form a composite encapsulation structure. Through the above design, this disclosure employs a special composite encapsulation design for the structure of the fin 200. Specifically, the composite encapsulation structure of the fin 200 consists of a graphene film 210, an alloy material layer 220, and a metal plate 230. The alloy material layer 220 is used to achieve structural connection between the metal plate 230 and the graphene film 210, realizing adhesion and orientation of the graphene film 210. This fully utilizes the high in-plane thermal conductivity of the graphene film 210, i.e., its high thermal conductivity in the lateral and perpendicular directions to the base plate 111, to improve the longitudinal thermal conductivity of the phase change heat exchanger. Simultaneously, because the alloy material layer 220 used in the fin 200 has a low melting point and can remain liquid during the operation of the heat-generating equipment, it possesses a certain enthalpy value, thereby improving the overall energy storage capacity of the phase change heat exchanger.

[0083] The foregoing has described and / or illustrated exemplary embodiments of the graphene-based phase change heat spreader proposed in this disclosure. However, the embodiments of this disclosure are not limited to the specific embodiments described herein; rather, components and / or steps of each embodiment may be used independently and separately from other components and / or steps described herein. Each component and / or step of one embodiment may also be used in combination with other components and / or steps of other embodiments. In describing the elements / components / etc. described and / or illustrated herein, the terms “a,” “an,” and “the above” are used to indicate the presence of one or more elements / components / etc. The terms “comprising,” “including,” and “having” are used to indicate an open-ended inclusion and mean that additional elements / components / etc. may exist in addition to those listed. Furthermore, the terms “first” and “second” in the claims and specification are used only as illustrative marks and are not intended to limit the numerical scope of the object.

[0084] Although the graphene-based phase change heat spreader proposed in this disclosure has been described with respect to different specific embodiments, those skilled in the art will recognize that modifications may be made to the implementation of this disclosure within the spirit and scope of the claims.

Claims

1. A graphene-based phase change temperature homogenizer, characterized in that, include: The housing (100) has a cavity (101) filled with phase change wax; as well as Multiple fins (200) are disposed in the cavity (101) and arranged perpendicularly to the bottom plate (111) of the shell (100). The bottom edge of the fins (200) contacts the bottom wall of the cavity (101), and the top edge of the fins (200) contacts the top wall of the cavity (101). The multiple fins (200) are spaced apart along a first direction (X) parallel to the bottom plate (111). Each fin (200) includes at least one layer of graphene film (210) and two layers of metal plates (…). The graphene film (210) and at least two alloy material layers (220) are provided. The two metal plates (230) are located on both sides of the graphene film (210) in the first direction (X). The alloy material layers (220) are respectively provided between two adjacent graphene films (210) and between the graphene film (210) and the metal plate (230). The melting point of the alloy material layer (220) is 150°C to 300°C. The multilayer structure of the fin (200) is encapsulated at the edge to form a composite encapsulation structure.

2. The graphene-based phase change temperature distribution plate according to claim 1, characterized in that: The alloy material layer (220) is made of a eutectic alloy comprising one or at least two of bismuth, tin, lead, and indium; and / or the metal plate (230) is made of aluminum.

3. The graphene-based phase change temperature distribution plate according to claim 1, characterized in that: The thickness of the graphene film (210) is 40 μm to 70 μm; and / or The thickness of the metal plate (230) is greater than or equal to 800 μm; and / or The thickness of the alloy material layer (220) is 1μm to 5μm.

4. The graphene-based phase change temperature homogenizer according to claim 1, characterized in that, The fin (200) has a first gap between its side edge in the second direction (Y) and the side wall of the cavity (101) in the second direction (Y).

5. The graphene-based phase change temperature homogenizer according to claim 4, characterized in that, The width of the first gap is 2mm to 4mm.

6. The graphene-based phase change temperature homogenizer according to claim 4, characterized in that, The graphene-based phase change heat spreader also includes a connecting assembly that can fix the plurality of fins (200) to the housing (100) along the first direction (X); the connecting assembly includes a plurality of connecting ribs (310) spaced apart along the first direction (X), the connecting ribs (310) connecting between two adjacent fins (200), or connecting between the fins (200) located at the end in the first direction (X) and the side wall of the cavity (101) in the first direction (X).

7. The graphene-based phase change temperature homogenizer according to claim 6, characterized in that, The height of the connecting rib (310) is less than the height of the fin (200) so that the bottom of the connecting rib (310) has a second gap with the bottom wall of the cavity (101), and / or so that the top of the connecting rib (310) has a third gap with the top wall of the cavity (101).

8. The graphene-based phase change temperature homogenizer according to claim 1, characterized in that, The plurality of fins (200) are arranged at equal intervals along the first direction (X).

9. The graphene-based phase change temperature homogenizer according to claim 1, characterized in that, The housing (100) has a protrusion (113) at one of the apex corners of the cavity (101). The protrusion (113) has a through hole (114) that connects the cavity (101) to the outside of the housing (100). The through hole (114) can be used as a vacuum hole for evacuating the cavity (101) and an injection hole for injecting phase change wax into the cavity (101).

10. The graphene-based phase change temperature homogenizer according to claim 1, characterized in that, The housing (100) includes a body (110) and a cover plate (120). The body (110) includes a bottom plate (111) and a side plate (112) disposed on the edge of the bottom plate (111). The cover plate (120) is disposed at the opening of the body (110). The body (110) and the cover plate (120) together form the cavity (101).

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