Graphene-aluminum heat plate and preparation method thereof

Abstract

The present application relates to the technical field of heat-conducting materials, and in particular to a graphene-aluminum heat plate and a preparation method thereof.The graphene-aluminum heat plate comprises a graphene layer and an aluminum layer, and the graphene layer and the aluminum layer are connected by a heat-conducting adhesive.The preparation method of the heat-conducting adhesive comprises the following steps: adding a base material and a curing agent into an organic solvent, stirring and uniformly mixing to obtain an adhesive base; modifying a heat-conducting filler system to obtain a modified heat-conducting filler system; and adding the modified heat-conducting filler system into the adhesive base, stirring and uniformly mixing to obtain the heat-conducting adhesive.The present application can solve the problems of complex preparation process and high production cost of graphene-aluminum composite materials.

Description

Technical Field

[0001] This invention relates to the technical field of thermally conductive materials, and more specifically, to a graphene aluminum heat spreader and its preparation method. Background Technology

[0002] As electronic devices continue to evolve towards miniaturization, high integration, and diversified functions, their assembly density and power density are constantly increasing, leading to a dramatic increase in heat generation. Traditional heat dissipation materials such as copper and aluminum have high thermal conductivity, but they suffer from poor electrical insulation and poor adhesion to electronic products, making it difficult to meet the requirements for efficient heat dissipation, high reliability, and lightweight electronic devices. While high thermal conductivity carbon-based materials, such as graphene, possess excellent thermal conductivity, they often suffer from poor mechanical properties. Therefore, high thermal conductivity composite materials using aluminum as the matrix and graphene as the thermal conductivity reinforcement have emerged.

[0003] Currently, the main methods for preparing graphene-aluminum matrix composites include powder metallurgy, casting, electrochemical deposition, high-pressure torsion, and friction stir welding. Traditional processing techniques typically require high temperature and high pressure conditions and are complex. For example, the powder consolidation process in powder metallurgy usually requires hot pressing for sintering, and the sintering time is generally long. Densification processes also require hot rolling and extrusion.

[0004] However, when graphene and aluminum are joined at high temperatures, graphene is prone to thermal expansion and delamination. Furthermore, carbon-based materials such as graphene are prone to interfacial reactions with metals at high temperatures, generating a brittle and easily hydrolyzed Al4C3 phase. This makes it difficult for the two to form a good bond, which can easily cause interlayer cracking and severely damage the mechanical and thermal properties of the composite material. Summary of the Invention

[0005] The present invention aims to solve the problem of poor interfacial bonding between graphene and aluminum substrate and difficulty in forming a good connection.

[0006] To address the above problems, this invention provides a graphene-aluminum heat spreader and its preparation method.

[0007] As a first aspect, the present invention relates to a graphene aluminum heat spreader, the graphene aluminum heat spreader comprising a graphene layer and an aluminum layer, the graphene layer and the aluminum layer being connected by a thermally conductive adhesive.

[0008] Optionally, the number of graphene layers and aluminum layers is not less than two, and the graphene layers and aluminum layers are stacked alternately, with each adjacent graphene layer and aluminum layer connected by thermally conductive adhesive.

[0009] Optionally, the method for preparing the thermally conductive adhesive includes the following steps:

[0010] Add the matrix material and curing agent to the organic solvent, stir and mix evenly to obtain the adhesive matrix;

[0011] The thermally conductive filler system was modified to obtain a modified thermally conductive filler system;

[0012] The modified thermally conductive filler system is added to the adhesive matrix and stirred until homogeneous to obtain the thermally conductive adhesive.

[0013] Optionally, the curing agent is 2-methylimidazole, and the amount of 2-methylimidazole added is 5 wt% to 10 wt% based on 100% of the mass of the matrix material.

[0014] Optionally, the modification of the thermally conductive filler system includes:

[0015] A silane coupling agent is added to an aqueous ethanol solution and stirred until homogeneous to obtain a modified solution.

[0016] The modified liquid was added to the dried thermally conductive filler system, and then ultrasonically dispersed and dried sequentially to obtain the modified thermally conductive filler system.

[0017] Optionally, the thermally conductive filler system is formed by compounding multiple thermally conductive fillers.

[0018] Optionally, based on 100 wt% of the thermally conductive filler system, the amount of silane coupling agent added is from 1 wt% to 5 wt%.

[0019] Optionally, the amount of the modified thermally conductive filler system added is 50 wt% to 90 wt%, based on 100 wt% of the mass of the adhesive matrix.

[0020] Secondly, the present invention relates to a method for preparing the above-mentioned graphene aluminum heat spreader, comprising:

[0021] The vacuum-de-bubbled thermally conductive adhesive is uniformly coated on the surfaces of the graphene layer and the aluminum layer. Then, the graphene layer and the aluminum layer are stacked and pressed together. Finally, they are insulated and cured sequentially to obtain a graphene aluminum heat spreader.

[0022] Optionally, the graphene layer and the aluminum layer are stacked and then pressed at 25 MPa to 50 MPa;

[0023] And / or, after stacking the graphene layer and the aluminum layer and pressing them, first heat-preserving them at 60°C to 80°C for 1 to 2 hours, and then curing them at 100°C to 120°C for 1 to 2 hours.

[0024] The advantages of this invention compared to the prior art include:

[0025] In this embodiment of the invention, the graphene layer and the aluminum layer are directly connected using a thermally conductive adhesive. The thermally conductive adhesive can wet and spread on the surfaces of both the aluminum and graphene layers, exhibiting good adhesion. Specifically, the thermally conductive adhesive can penetrate into the pores on the graphene surface and expel air adsorbed at the interface between the aluminum and graphene layers, resulting in adhesion, forming a mechanically embedded and clean surface, generating a reactive surface, and improving the bonding strength. The critical surface tension of the aluminum layer is greater than the surface tension of the thermally conductive adhesive, allowing the adhesive to penetrate the pits and pores on the aluminum layer surface to form good wetting and adsorption. Wetting allows the thermally conductive adhesive to be in close contact with the aluminum layer, relying on intermolecular forces (including hydrogen bonds and van der Waals forces) to generate a permanent bond. This achieves a reliable connection between the graphene and aluminum layers at low temperatures, thus avoiding the problem of interfacial reactions at high temperatures that affect the interfacial bonding effect.

[0026] Furthermore, the thermally conductive adhesive can directly form phonon and electron thermal conduction pathways between the aluminum and graphene layers, providing a path for heat conduction. The adhesive can also fill the tiny gaps between the graphene and aluminum, ensuring close contact and thus reducing thermal resistance and improving heat transfer efficiency. This invention provides a graphene-aluminum heat sink based on adhesive bonding, significantly improving its thermal conductivity while maintaining mechanical properties. The joint welding rate reaches over 99%, its interface strength is higher than 10 MPa, and its thermal conductivity is greater than 300 W / (m·K). The use of thermally conductive adhesive simplifies the bonding process between the graphene and aluminum layers, eliminating the need for complex processes or equipment. This helps reduce production costs and improve production efficiency, aligning with the principles of green and energy-saving production. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the graphene aluminum heat sink in Embodiment 1 of the present invention.

[0028] Explanation of reference numerals in the attached figures:

[0029] 1. Graphene layer; 2. Aluminum layer. Detailed Implementation

[0030] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Although some embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the accompanying drawings and embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0031] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing particular embodiments only and is not intended to limit this application.

[0032] The term "comprising" and its variations as used herein are open-ended, meaning "including but not limited to"; the term "based on" means "at least partially based on"; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments"; and the term "optionally" means "optional embodiments". Definitions of other terms will be given in the description below. It should be noted that the concepts of "first," "second," etc., mentioned in this invention are used to distinguish different objects, not to describe a specific order or hierarchy. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0033] Methods for joining dissimilar materials include brazing, diffusion welding, and SPS, but the following problems are common when using the above processes to join graphene and aluminum: (1) The wettability of the aluminum alloy and graphene interface is poor. The contact angle between graphene and aluminum is about 140°. The interface between the two is prone to pores and defects, resulting in low interface bonding strength and high interface thermal resistance, making it difficult to join by brazing; (2) Carbon-based materials such as graphene are prone to interface reactions with metals at high temperatures, generating brittle and easily hydrolyzed Al4C3 phases, which are seriously detrimental to the mechanical and thermal properties of composite materials, making it difficult to form a good connection when the two are diffused welded, and easily causing interlayer cracking; (3) The thermal expansion coefficients between graphene and aluminum are large, resulting in severe thermal mismatch at the interface. When subjected to thermal cycling or thermal shock, significant stress concentration will occur, and interlayer cracking is very likely to occur above 200°C, resulting in low interface bonding reliability.

[0034] Therefore, powder metallurgy and casting are the most commonly used methods for preparing graphene-aluminum composite materials.

[0035] Powder metallurgy generally includes three stages: uniform mixing of graphene and aluminum powder, powder consolidation, and densification. Among these, the uniform mixing and dispersion of graphene and aluminum powder is the key preliminary stage of powder metallurgy, and there are several preparation methods, including mechanical ball milling, sheet powder metallurgy, and in-situ self-generated powder.

[0036] Mechanical ball milling is a process that mixes various powders under the grinding action of ball milling media. It mainly achieves powder breakage and dispersion through the collision, impact, and shearing action of the grinding balls. Flake powder metallurgy is based on the biomimetic idea of ​​seashells, relying on the electrostatic interaction between graphene oxide and the surface of aluminum powder to disperse graphene. The core idea of ​​in-situ self-generation method is to reduce carbon-containing organic matter to graphene on the surface of aluminum particles during heating. Generally, copper or nickel metal particles are selected as growth substrates and mixed with aluminum powder. The method of growing graphene on the metal surface can construct a three-dimensional / quasi-three-dimensional graphene network structure. The biggest advantage of in-situ self-generation preparation of graphene is that it can solve the problem of graphene agglomeration, while providing three-dimensional constraints on the matrix, resulting in good toughness while strengthening it.

[0037] Powder consolidation processes mainly include hot pressing and spark plasma sintering. Hot pressing has relatively low heating efficiency and a long sintering time. Spark plasma sintering directly uses electric current to heat the mold and sintering material. Compared with hot pressing, it has extremely high heating efficiency, fast heating rate, low sintering temperature, and short holding time, but the machine cost is relatively high.

[0038] The melting and casting method generally includes processes such as pressure infiltration, stirred casting, and spray deposition. Compared with powder metallurgy, it is more difficult to achieve uniform dispersion of graphene in composite materials prepared by melting and casting. Moreover, the preparation of graphene-aluminum matrix composites by melting and casting is still in the laboratory research stage. How to improve the dispersion of graphene on an industrial scale to meet the application requirements remains to be solved.

[0039] Based on the problems existing in the above-mentioned related technologies, this invention provides a graphene aluminum heat spreader and its preparation method.

[0040] In a first aspect, the graphene aluminum heat spreader in the embodiments of the present invention includes a graphene layer 1 and an aluminum layer 2, which are connected by a thermally conductive adhesive.

[0041] In this embodiment of the invention, graphene layer 1 and aluminum layer 2 are directly connected using thermally conductive adhesive. The thermally conductive adhesive can wet and spread on the surfaces of aluminum layer 2 and graphene layer 1, exhibiting good adhesion. Specifically, the thermally conductive adhesive can penetrate into the voids on the graphene surface and expel air adsorbed at the interface between aluminum layer 2 and graphene layer 1, resulting in adhesion, forming a mechanically embedded and clean surface, generating a reactive surface, and improving the bonding strength. The critical surface tension of aluminum layer 2 is greater than the surface tension of the thermally conductive adhesive, allowing the adhesive to penetrate into the pits and voids on the surface of aluminum layer 2, forming good wetting and generating adsorption. Wetting allows the thermally conductive adhesive to be in close contact with aluminum layer 2, relying on intermolecular forces (including hydrogen bonds and van der Waals forces) to generate a permanent bond, achieving a reliable connection between graphene layer 1 and aluminum layer 2 at low temperatures. This avoids the problem of interface reactions easily occurring between graphene layer 1 and aluminum layer 2 at high temperatures, which affects the interface bonding effect.

[0042] Furthermore, the thermally conductive adhesive can directly form phonon and electron thermal conduction pathways between the aluminum layer 2 and the graphene layer 1, providing a path for heat conduction. The adhesive can also fill the tiny gaps between the graphene and aluminum, ensuring close contact and reducing thermal resistance, thereby improving heat conduction efficiency. This invention provides a graphene-aluminum heat sink based on adhesive bonding, significantly improving its thermal conductivity while maintaining mechanical properties. The joint welding rate reaches over 99%, its interface strength is higher than 10 MPa, and its thermal conductivity is greater than 300 W / (m·K). The use of thermally conductive adhesive simplifies the bonding process between the graphene layer 1 and the aluminum layer 2, eliminating the need for complex processes or equipment. This helps reduce production costs and improve production efficiency, aligning with the principles of green and energy-saving production.

[0043] Optionally, the number of graphene layer 1 and aluminum layer 2 is not less than two, and the graphene layer 1 and aluminum layer 2 are stacked alternately, with each adjacent graphene layer 1 and aluminum layer 2 connected by thermally conductive adhesive.

[0044] Graphene possesses excellent flexibility and bending resistance, while aluminum, as a metallic material, exhibits higher mechanical strength. This invention employs alternating stacks of multiple layers of graphene and aluminum, which not only improves the overall heat dissipation performance and mechanical strength of the heat spreader but also fully utilizes the inherent flexibility of graphene, resulting in better overall flexibility of the heat spreader. This allows it to meet the heat dissipation needs of devices with different shapes and is suitable for various products such as foldable screen phones.

[0045] In some optional embodiments, the method for preparing the thermally conductive adhesive of the present invention may include the following steps:

[0046] S1: Add the matrix material and curing agent to the organic solvent, stir and mix evenly to obtain the adhesive matrix.

[0047] The organic solvent can be anhydrous ethanol, and the matrix material can be a colloid such as epoxy resin, polyurethane, or silicone. Preferably, the matrix material in this embodiment is an epoxy resin, specifically bisphenol A type epoxy, phenolic epoxy, and alicyclic epoxy colloids. The curing agent can be 2-methylimidazole.

[0048] Specifically, anhydrous ethanol is used as the solvent for the gel matrix, and then epoxy resin colloid and 2-methylimidazole are added sequentially. The amount of 2-methylimidazole added is 5 wt% to 10 wt% based on 100% of the mass of the matrix material. After mixing evenly, the mixture is placed in a fume hood for 1 to 2 hours to obtain the gel matrix.

[0049] S2: Modify the thermally conductive filler system to obtain a modified thermally conductive filler system.

[0050] Specifically, the thermally conductive filler system can be metallic fillers such as copper, silver, aluminum, and gold; metallic nitrides such as boron nitride and aluminum nitride; metallic oxides such as aluminum oxide or magnesium oxide; non-metallic oxides such as silicon oxide; or non-metallic carbides such as silicon carbide. Preferably, the thermally conductive filler system can be obtained by compounding various thermally conductive fillers with different particle sizes and morphologies in a specific ratio.

[0051] Furthermore, the thermally conductive filler system can be modified using a silane coupling agent, such as KH550, KH560, or KH570. Specifically, the silane coupling agent is first added to an ethanol-water solution with a concentration of 70wt% to 95wt%, and stirred until homogeneous to obtain a modified solution. The amount of silane coupling agent added is 1wt% to 5wt% based on a 100wt% mass of the thermally conductive filler system. The modified solution is then added to the dried thermally conductive filler system and ultrasonically dispersed for 15 to 30 minutes to ensure the silane coupling agent is uniformly dispersed on the surface of the thermally conductive filler. Finally, the system is dried at 70℃ to 80℃ for 1 to 2 hours to allow the thermally conductive filler and silane coupling agent to fully react, resulting in the modified thermally conductive filler system.

[0052] It should be noted that before adding the modifying liquid, the thermally conductive filler system to be treated should be dried for more than 12 hours to fully remove moisture or other volatile substances from the filler, so as to ensure the stability and performance of the filler during use.

[0053] S3: Add the modified thermally conductive filler system to the adhesive matrix and stir to mix evenly to obtain the thermally conductive adhesive. The amount of modified thermally conductive filler system added is 50 wt% to 90 wt%, based on 100 wt% of the adhesive matrix.

[0054] This invention employs a silane coupling agent to modify the surface of the thermally conductive filler, effectively improving the interfacial properties between the inorganic filler and the resin matrix and enhancing its wettability. Testing shows that the thermally conductive adhesive prepared using the above process achieves a strength of 10-15 MPa and a thermal conductivity of 1-2 W / (m·K), which is beneficial for achieving a reliable connection between graphene layer 1 and aluminum layer 2.

[0055] Secondly, embodiments of the present invention also provide a method for preparing the above-mentioned graphene aluminum heat exchange plate, comprising: uniformly coating the surface of the graphene layer 1 and the aluminum layer 2 with a vacuum defoaming thermally conductive adhesive, then stacking the graphene layer 1 and the aluminum layer 2 and pressing them together, and finally performing heat preservation and curing in sequence to obtain the graphene aluminum heat exchange plate.

[0056] Specifically, graphene layer 1 and aluminum layer 2 can be stacked and pressed at 25 MPa to 50 MPa. After stacking and pressing graphene layer 1 and aluminum layer 2, the mixture can be held at 60℃ to 80℃ for 1 to 2 hours, and then cured at 100℃ to 120℃ for 1 to 2 hours to obtain a graphene-aluminum heat sink.

[0057] Furthermore, for a graphene aluminum heat spreader containing multiple graphene layers 1 and aluminum layers 2, thermally conductive adhesive can be uniformly coated on the upper and lower surfaces of graphene layers 1 and aluminum layers 2 by screen printing. Then, the graphene layers 1 and aluminum layers 2 coated with thermally conductive adhesive are assembled layer by layer in a mold, so that each adjacent graphene layer 1 and aluminum layer 2 are connected by thermally conductive adhesive.

[0058] The present invention will be described in detail below through specific embodiments and comparative examples:

[0059] Example 1

[0060] (I) Preparation of thermally conductive adhesive

[0061] Preparation of the gel matrix: Epoxy resin EPIKOTE 828 and 2-methylimidazole were added to anhydrous ethanol, stirred until homogeneous, and placed in a fume hood for 2 hours to obtain the gel matrix. The amount of 2-methylimidazole added was 5 wt%, based on 100 wt% of epoxy resin EPIKOTE 828.

[0062] Preparation of the modified thermally conductive filler system: Aluminum nitride, alumina, silicon dioxide, and silicon carbide were compounded in a ratio of 1:1:1:1 to obtain a thermally conductive filler compound system, which was then dried in a drying oven for 15 hours. Simultaneously, silane coupling agent KH560 was added to a 70 wt% ethanol aqueous solution to obtain a modified solution. The amount of silane coupling agent KH560 added was 1 wt% of the thermally conductive filler compound system. The prepared modified solution was added to the filler system and ultrasonically dispersed for 30 minutes. Finally, it was dried in a drying oven at 70℃ for 2 hours to obtain the modified thermally conductive filler system.

[0063] Preparation of thermally conductive adhesive: The modified thermally conductive filler system is added to the adhesive matrix and stirred thoroughly to obtain the thermally conductive adhesive. The amount of modified thermally conductive filler system added is 50 wt% of 100 wt% of the adhesive matrix.

[0064] (II) Preparation of graphene aluminum heat sink

[0065] Graphene-aluminum based multilayer heat spreaders with dimensions ranging from 10mm×10mm to 500mm×500mm were prepared using the aforementioned thermally conductive adhesive. (Refer to...) Figure 1As shown in the figure, the arrows indicate the pressing direction. In this embodiment, the bottom layer of the graphene aluminum vapor chamber is graphene layer 1, and the top layer is aluminum layer 2. Both graphene layer 1 and aluminum layer 2 have 9 layers. The prepared thermally conductive adhesive is defoamed under vacuum. Then, the thermally conductive adhesive is uniformly coated onto the upper and lower surfaces of graphene layer 1 and aluminum layer 2 using screen printing. The graphene layer 1 and aluminum layer 2 coated with thermally conductive adhesive are then assembled layer by layer into a mold and pressed at 25 MPa. Finally, it is placed in a vacuum drying oven and kept at 60°C for 2 hours, followed by curing at 100°C for 1 hour to obtain the graphene aluminum vapor chamber.

[0066] Example 2

[0067] The difference between this embodiment and Example 1 is that, in the preparation process of the thermally conductive adhesive, based on 100wt% of epoxy resin EPIKOTE828, the amount of 2-methylimidazole added is 10wt%; based on 100wt% of the thermally conductive filler system, the amount of silane coupling agent KH560 added is 5wt% of the thermally conductive filler compound system; and based on 100wt% of the adhesive matrix, the amount of modified thermally conductive filler system added is 90wt%.

[0068] Comparative Example 1

[0069] In this comparative example, nickel was first plated on the surfaces of the graphene layer and the aluminum layer, respectively. Then, the nickel-plated graphene layer and the nickel-plated aluminum layer were soldered together to obtain a graphene-aluminum heat sink.

[0070] Comparative Example 2

[0071] In this comparative example, a copper layer is first formed on the surface of an aluminum substrate by electroplating or magnetron sputtering, and then a graphene layer is formed on the copper layer by plasma chemical vapor deposition to obtain a graphene aluminum heat sink.

[0072] The interfacial strength and thermal conductivity of the graphene-aluminum vapor chambers in Examples 1-2 and Comparative Examples 1-2 were tested respectively, and the results are shown in Table 1:

[0073] Table 1. Interface strength and thermal conductivity of the graphene-aluminum vapor chambers in Examples 1-2 and Comparative Examples 1-2.

[0074]

[0075] As shown in Table 1, the thermal conductivity of the graphene-aluminum vapor chambers in Examples 1 and 2 is significantly higher than that in Comparative Examples 1 and 2, and they also possess relatively good interfacial strength. This indicates that the graphene-aluminum vapor chambers in the embodiments of the present invention have made outstanding progress in thermal conductivity while also possessing good mechanical properties.

[0076] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A graphene-aluminum heat spreader, characterized in that, It includes a graphene layer (1) and an aluminum layer (2), wherein the graphene layer (1) and the aluminum layer (2) are connected by a thermally conductive adhesive; The number of graphene layer (1) and aluminum layer (2) is not less than two, and the graphene layer (1) and aluminum layer (2) are stacked alternately, and adjacent graphene layer (1) and aluminum layer (2) are connected by thermally conductive adhesive. The preparation method of the thermally conductive adhesive includes the following steps: adding a matrix material and a curing agent to an organic solvent, stirring and mixing evenly to obtain a matrix; modifying the thermally conductive filler system to obtain a modified thermally conductive filler system, wherein the modification of the thermally conductive filler includes: adding a silane coupling agent to an ethanol aqueous solution, stirring and mixing evenly to obtain a modified liquid; adding the modified liquid to the dried thermally conductive filler system, and then sequentially performing ultrasonic dispersion and drying to obtain a modified thermally conductive filler system; adding the modified thermally conductive filler system to the matrix, stirring and mixing evenly to obtain the thermally conductive adhesive; The preparation method of the graphene aluminum heat sink includes: The thermally conductive adhesive, after vacuum degassing, is uniformly coated on the surface of the graphene layer (1) and the aluminum layer (2). Then, the graphene layer (1) and the aluminum layer (2) are stacked and pressed. Finally, they are insulated and cured in sequence to obtain a graphene aluminum heat spreader.

2. The graphene-aluminum heat spreader according to claim 1, characterized in that, The curing agent is 2-methylimidazole, and the amount of 2-methylimidazole added is 5 wt% to 10 wt% based on 100% of the mass of the matrix material.

3. The graphene-aluminum heat spreader according to claim 1, characterized in that, The thermally conductive filler system is formed by a compound of various thermally conductive fillers.

4. The graphene-aluminum heat spreader according to claim 1, characterized in that, Based on a mass of 100 wt% of the thermally conductive filler system, the amount of silane coupling agent added is 1 wt% to 5 wt%.

5. The graphene-aluminum heat spreader according to claim 1, characterized in that, Based on a mass of 100 wt% of the adhesive matrix, the amount of the modified thermally conductive filler system added is 50 wt% to 90 wt%.

6. The graphene-aluminum heat spreader according to claim 1, characterized in that, The graphene layer (1) and the aluminum layer (2) are stacked and then pressed at 25 MPa to 50 MPa. And / or, after stacking the graphene layer (1) and the aluminum layer (2) and pressing them, first heat-preserving them at 60°C to 80°C for 1 to 2 hours, and then curing them at 100°C to 120°C for 1 to 2 hours.

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