Radiation-proof graphite heat dissipation film and preparation method thereof

Abstract

The invention relates to the technical field of heat conduction and heat dissipation materials, and particularly discloses an anti-radiation graphite heat dissipation film and a preparation method thereof.The anti-radiation graphite heat dissipation film comprises two graphene composite layers, a shielding metal grid is arranged between the two graphene composite layers, and each graphene composite layer comprises a graphene layer and a base material which are bonded to each other; and the base material and the shielding metal grid are integrally formed. The graphene heat dissipation film is endowed with anti-radiation performance by arranging the shielding metal grid, the shielding metal grid is arranged between the two graphene layers, the graphene heat dissipation film is provided with a metal structure, so that the overall structural strength of the graphene heat dissipation film is improved, and meanwhile, the shielding metal grid is provided with the mesh holes, so that the shielding metal grid is more uniform in radiation. The grid holes not only can block radiation, but also provide an extension space for the graphene heat dissipation film when the graphene heat dissipation film is bent, so that the flexibility of the graphene heat dissipation film is greatly improved.

Description

Technical Field

[0001] The invention relates to the technical field of thermal conductive and heat dissipating materials, and in particular to a radiation-proof graphite heat dissipating film and a preparation method thereof. Background Art

[0002] Heat dissipation film is a commonly used heat dissipation material in high-power communication equipment. Among them, graphene is one of the most widely used materials. Due to its outstanding heat dissipation performance and advantages such as high temperature resistance and corrosion resistance, it has great potential in local heat dissipation of electronic products.

[0003] Currently on the market, most graphene heat dissipation films with a metal layer as the base layer are used to dissipate heat from electronic products. Among them, the most common is the copper foil base layer. Then, in order to improve the functionality of the heat dissipation film, various functional layers (such as radiation protection layer, wear-resistant and waterproof layer, electrostatic adsorption layer, etc.) are prepared separately according to actual needs. The various functional layers and the graphene layer are placed in a heat sealing machine for thermal bonding to form a composite film. However, this type of composite film is insufficient in flexibility. The composite film is prone to breakage after being bent to a certain degree. Therefore, how to make the heat dissipation film have both radiation protection and flexibility has always been a problem to be solved urgently in this field. Based on this, the present invention is proposed. Summary of the invention

[0004] In order to solve the technical problems existing in the above-mentioned prior art, the present invention provides a radiation-proof graphite heat dissipation film and a preparation method thereof.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solution: a radiation-proof graphite heat dissipation film, comprising two graphene composite layers, a shielding metal grid is arranged between the two graphene composite layers, wherein the graphene composite layer comprises a graphene layer and a substrate bonded to each other, and the substrate and the shielding metal grid are integrally formed.

[0006] Preferably, the graphene layer adopts a natural graphene heat dissipation film or a polyimide artificial graphene heat dissipation film.

[0007] Preferably, the substrate is copper foil or aluminum foil with a thickness of 0.001 to 1200 μm.

[0008] In addition, the present invention also proposes a method for preparing the above-mentioned radiation-proof graphite heat dissipation film, comprising the following steps:

[0009] S1. preparing a shielding metal grid;

[0010] S2. Prepare a graphene layer, and adhere the prepared graphene layer to both sides of the shielding metal grid.

[0011] Preferably, in S1, a metal film is deposited on a substrate by chemical vapor deposition or physical vapor deposition technology, and then a grid structure is formed on the substrate by electroplating.

[0012] Preferably, the graphene layer adopts a natural graphene heat dissipation film, and the specific preparation method thereof is:

[0013] S21, preparing an aqueous graphene oxide slurry: adding graphene oxide to deionized water to prepare an aqueous graphene oxide solution, and uniformly dispersing the graphene oxide in the deionized water by ultrasonic stirring to obtain an aqueous graphene oxide slurry;

[0014] S22. The aqueous slurry of graphene oxide is placed in a container equipped with a filter membrane, and vacuum filtration is performed under vacuum conditions. While the filtration is being performed, the container is rotated at a uniform speed, and the graphene membrane is evenly distributed on the filter membrane of the container under the action of centrifugal force. Finally, the filter membrane is taken out and the graphene membrane is separated from the filter membrane.

[0015] Preferably, the graphene layer adopts a polyimide artificial graphene heat dissipation film, and its specific preparation method is: high-temperature carbonization of the polyimide film under vacuum conditions to obtain a polyimide carbonized film; high-temperature graphitization of the polyimide carbonized film to obtain a graphene heat dissipation film.

[0016] Preferably, the polyimide film is subjected to a gradient heating and heat preservation operation during high-temperature carbonization, specifically: firstly, the temperature is increased to 350-550°C at a heating rate of 5-8°C / min, and the temperature is kept for 60 minutes; then, the temperature is increased to 650-800°C at a heating rate of 5-8°C / min, and the temperature is kept for 60 minutes; then, the temperature is increased to 1000-1200°C at a heating rate of 5-8°C / min, and the temperature is kept for 60 minutes;

[0017] The specific steps of high-temperature graphitization of polyimide film are as follows: first, heating to 1700-1900°C at a heating rate of 5-8°C / min, and keeping warm for 20 minutes; then heating to 2100-2300°C at a heating rate of 5-8°C / min, and keeping warm for 20 minutes; then heating to 2500-2700°C at a heating rate of 5-8°C / min, and keeping warm for 20 minutes.

[0018] Preferably, in S2, during the process of the graphene layer being adhered to the shielding metal grid, the substrate is heated, and the heating temperature ranges from 40°C to 80°C.

[0019] Compared with the prior art, the present invention provides a radiation-proof graphite heat dissipation film and a preparation method thereof, which has the following beneficial effects:

[0020] (1) The present invention provides the graphene heat dissipation film with radiation protection performance by providing a shielding metal grid, and the shielding metal grid is provided between two graphene layers. Since the graphene heat dissipation film is provided with a metal structure, the overall structural strength of the graphene heat dissipation film is increased. At the same time, mesh holes are provided on the shielding metal grid. The mesh holes can not only block radiation, but also provide extension space for the graphene heat dissipation film when the graphene heat dissipation film is bent, thereby greatly increasing the flexibility of the graphene heat dissipation film.

[0021] (2) The present invention makes full use of the substrate and deposits the metal grid material on the inner side of the substrate through vapor deposition technology, while the outer side of the substrate is directly bonded to the graphene layer, thereby saving the overall manufacturing material of the heat dissipation film.

[0022] (3) The graphene layer distributed on both sides of the shielding metal grid in the present invention can be selected from natural graphene heat dissipation film, polyimide artificial graphite film, or even a mixture of the two films to prepare the heat dissipation film. While meeting the radiation protection performance, the prepared graphene heat dissipation film has good thermal conductivity and mechanical properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Schematic diagram of the structure of the radiation-proof graphite heat dissipation film in an embodiment of the present invention.

[0024] In the figure, 1, first graphene layer; 2, second graphene layer; 3, first substrate; 4, shielding metal grid; 5, second substrate. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0026] It should be noted that the following embodiments and features in the embodiments may be combined with each other in the absence of conflict; and, based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in the field without making any creative work are within the scope of protection of the present disclosure.

[0027] Various aspects of the embodiments within the scope of the appended claims are described below. It should be apparent that the aspects described herein may be embodied in a wide variety of forms, and any specific structure and / or function described herein is merely illustrative. Based on this disclosure, it should be understood by those skilled in the art that an aspect described herein may be implemented independently of any other aspect, and two or more of these aspects may be combined in various ways. For example, any number of aspects described herein may be used to implement a device and / or practice a method. In addition, other structures and / or functionality other than one or more of the aspects described herein may be used to implement this device and / or practice this method.

[0028] Embodiment 1

[0029] This embodiment provides an anti-radiation graphite heat dissipation film, including two graphene composite layers of the same specification, the graphene composite layer includes a graphene layer and a substrate, and a shielding metal grid 4 is arranged between the two graphene composite layers. Figure 1 As shown, the top and bottom of the shielding metal grid 4 are respectively provided with a first substrate 3 and a second substrate 5 , and the first graphene layer 1 is bonded to the surface of the first substrate 3 , and the second graphene layer 2 is bonded to the surface of the second substrate 5 .

[0030] The first substrate 3 and the second substrate 5 have the same specifications and are made of copper foil or aluminum foil with a thickness of 0.001-1200 μm. The above two substrates are preferably copper foil, which has good calendering performance and excellent thermal conductivity, and can not only play a supporting role of the carrier, but also assist the heat dissipation film in heat conduction and heat dissipation.

[0031] The preparation process of radiation-proof graphite heat dissipation film is as follows:

[0032] (1) Selecting a corresponding type of graphene oxide according to demand, adding the graphene oxide to deionized water to prepare an aqueous graphene oxide solution, and using ultrasonic stirring to uniformly disperse the graphene oxide in the deionized water to obtain an aqueous graphene oxide slurry, wherein the mass fraction of the aqueous graphene oxide solution is 2% to 6%.

[0033] (2) The aqueous slurry of graphene oxide is placed in a container equipped with a filter membrane, and vacuum filtration is performed under a vacuum degree of 0.1 to -0.3 MPa. The container is rotated evenly at a speed of 200 to 400 rpm for 30 to 60 minutes. The graphene membrane is evenly distributed on the filter membrane of the container under the action of centrifugal force. The filter membrane is taken out and the graphene membrane is separated from the filter membrane.

[0034] (3) Using chemical vapor deposition or physical vapor deposition technology, copper and aluminum metal films with good conductivity are selected to be deposited on the first substrate 3 and the second substrate 5 respectively, and then a shielding metal grid 4 is formed on the above two substrates by electroplating technology. Subsequently, the first substrate 3 and the second substrate 5 are bonded together at the edges facing each other using radiation-proof white latex. In actual operation, a small portion of the periphery of the first substrate 3 and the second substrate 5 can be left empty without electroplating, and the empty portion is filled with radiation-proof white latex to bond the first substrate 3 and the second substrate 5. The grid holes on the surface of the shielding metal grid 4 itself can block radiation, and the radiation-proof white latex at the connection between the first substrate 3 and the second substrate 5 also has radiation-proof performance, so the radiation-proof area of ​​the entire graphene heat dissipation film will not be reduced.

[0035] (4) The graphene film obtained in (2) is adhered to the surface of the shielding metal grid 4 by means of an adhesive material. The adhesive material is not specifically limited in this embodiment, and can be specifically selected from one of epoxy resin, phenolic resin, urea-formaldehyde resin, melamine-formaldehyde resin, acrylic resin, and silicone resin. The above resins are all viscous resins and can adhere and fix the graphene film to the surface of the substrate. In the process of adhering the graphene layer to the shielding metal grid, the substrate can be heated by a heating device such as an infrared lamp, and the heating temperature is maintained at 40°C to 80°C to promote the adhesion of the graphene film and the substrate.

[0036] Embodiment 2

[0037] This embodiment provides an anti-radiation graphite heat dissipation film, including two graphene composite layers of the same specification, the graphene composite layer includes a graphene layer and a substrate, and a shielding metal grid 4 is arranged between the two graphene composite layers. Figure 1 As shown, the top and bottom of the shielding metal grid 4 are respectively provided with a first substrate 3 and a second substrate 5 , and the first graphene layer 1 is bonded to the surface of the first substrate 3 , and the second graphene layer 2 is bonded to the surface of the second substrate 5 .

[0038] The first substrate 3 and the second substrate 5 have the same specifications and are made of copper foil or aluminum foil with a thickness of 0.001-1200 μm. The above two substrates are preferably copper foil, which has good calendering performance and excellent thermal conductivity, and can not only play a supporting role of the carrier, but also assist the heat dissipation film in heat conduction and heat dissipation.

[0039] The preparation process of radiation-proof graphite heat dissipation film is as follows:

[0040] (1) A polyimide film was selected and first subjected to high-temperature carbonization under a vacuum degree of 0.01 to -0.1 MPa. The temperature was first increased to 350 to 550°C at a heating rate of 5 to 8°C / min and kept warm for 60 min; then the temperature was increased to 650 to 800°C at a heating rate of 5 to 8°C / min and kept warm for 60 min; then the temperature was increased to 1000 to 1200°C at a heating rate of 5 to 8°C / min and kept warm for 60 min.

[0041] (2) The carbonized polyimide film in (1) is first heated to 1700-1900°C at a heating rate of 5-8°C / min and kept warm for 20 minutes; then heated to 2100-2300°C at a heating rate of 5-8°C / min and kept warm for 20 minutes; then heated to 2500-2700°C at a heating rate of 5-8°C / min and kept warm for 20 minutes to obtain a graphene heat dissipation film.

[0042] (3) Using chemical vapor deposition or physical vapor deposition technology, copper and aluminum metal films with good conductivity are selected to be deposited on the first substrate 3 and the second substrate 5 respectively, and then a shielding metal grid 4 is formed on the above two substrates by electroplating technology. Subsequently, the first substrate 3 and the second substrate 5 are bonded together at the edges facing each other using radiation-proof white latex. In actual operation, a small portion of the periphery of the first substrate 3 and the second substrate 5 can be left empty without electroplating, and the empty portion is filled with radiation-proof white latex to bond the first substrate 3 and the second substrate 5. The grid holes on the surface of the shielding metal grid 4 itself can block radiation, and the radiation-proof white latex at the connection between the first substrate 3 and the second substrate 5 also has radiation-proof performance, so the radiation-proof area of ​​the entire graphene heat dissipation film will not be reduced.

[0043] (4) The graphene film obtained in (2) is adhered to the surface of the shielding metal grid 4 by means of an adhesive material. The adhesive material is not specifically limited in this embodiment, and can be specifically selected from one of epoxy resin, phenolic resin, urea-formaldehyde resin, melamine-formaldehyde resin, acrylic resin, and silicone resin. The above resins are all viscous resins and can adhere and fix the graphene film to the surface of the substrate. In the process of adhering the graphene layer to the shielding metal grid, the substrate can be heated by a heating device such as an infrared lamp, and the heating temperature is maintained at 40°C to 80°C to promote the adhesion of the graphene film and the substrate.

[0044] Embodiment 3

[0045] The inventive concept proposed in this embodiment is the same as that in the first embodiment. The difference between this embodiment and the first embodiment is that the second graphene layer 2 on the surface of the second substrate 5 is the graphene heat dissipation film prepared in the second embodiment.

[0046] Embodiment 4

[0047] The inventive concept proposed in this embodiment is the same as that in the second embodiment. The difference between this embodiment and the second embodiment is that the first graphene layer 1 on the surface of the first substrate 3 adopts the graphene heat dissipation film in the first embodiment.

[0048] In summary, the present invention imparts radiation protection performance to the graphene heat dissipation film by setting a shielding metal grid, and the shielding metal grid is set between two graphene layers. Since the graphene heat dissipation film is provided with a metal structure, the overall structural strength of the graphene heat dissipation film is increased. At the same time, mesh holes are set on the shielding metal grid. The mesh holes can not only block radiation, but also provide extension space for the graphene heat dissipation film when the graphene heat dissipation film is bent, thereby greatly increasing the flexibility of the graphene heat dissipation film.

[0049] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A radiation-proof graphite heat dissipation film, characterized in that: It comprises two graphene composite layers, a shielding metal grid (4) is arranged between the two graphene composite layers, wherein the graphene composite layer comprises a graphene layer and a substrate bonded to each other, and the substrate and the shielding metal grid (4) are integrally formed.

2. The radiation-proof graphite heat dissipation film according to claim 1, characterized in that: The graphene layer adopts natural graphene heat dissipation film or polyimide artificial graphene heat dissipation film.

3. The radiation-proof graphite heat dissipation film according to claim 1, characterized in that: The substrate is copper foil or aluminum foil with a thickness of 0.001-1200 μm.

4. A method for preparing the radiation-proof graphite heat dissipation film according to any one of claims 1 to 3, characterized in that: The steps include: S1, preparing a shielding metal grid (4); S2, preparing a graphene layer, and the prepared graphene layer is adhered to both sides of the shielding metal grid (4).

5. The method for preparing a radiation-proof graphite heat dissipation film according to claim 4, characterized in that: In S1, a metal film is deposited on a substrate using chemical vapor deposition or physical vapor deposition technology, and then a grid structure is formed on the substrate by electroplating.

6. The method for preparing a radiation-proof graphite heat dissipation film according to claim 4, characterized in that: The graphene layer adopts natural graphene heat dissipation film, and its specific preparation method is as follows: S21, preparing an aqueous graphene oxide slurry: adding graphene oxide to deionized water to prepare an aqueous graphene oxide solution, and uniformly dispersing the graphene oxide in the deionized water by ultrasonic stirring to obtain an aqueous graphene oxide slurry; S22. The aqueous slurry of graphene oxide is placed in a container equipped with a filter membrane, and vacuum filtration is performed under vacuum conditions. While the filtration is being performed, the container is rotated at a uniform speed, and the graphene membrane is evenly distributed on the filter membrane of the container under the action of centrifugal force. Finally, the filter membrane is taken out and the graphene membrane is separated from the filter membrane.

7. The radiation-proof graphite heat dissipation film according to claim 1, characterized in that: The graphene layer adopts a polyimide artificial graphene heat dissipation film, and its specific preparation method is: high-temperature carbonization of the polyimide film under vacuum conditions to obtain a polyimide carbonized film; high-temperature graphitization of the polyimide carbonized film to obtain a graphene heat dissipation film.

8. The radiation-proof graphite heat dissipation film according to claim 7, characterized in that: The polyimide film is subjected to a gradient heating and heat preservation operation during high-temperature carbonization, specifically: firstly, the temperature is raised to 350-550°C at a heating rate of 5-8°C / min, and the temperature is kept for 60 minutes; then, the temperature is raised to 650-800°C at a heating rate of 5-8°C / min, and the temperature is kept for 60 minutes; then, the temperature is raised to 1000-1200°C at a heating rate of 5-8°C / min, and the temperature is kept for 60 minutes; The specific steps of high-temperature graphitization of polyimide film are as follows: first, heating to 1700-1900°C at a heating rate of 5-8°C / min, and keeping warm for 20 minutes; then heating to 2100-2300°C at a heating rate of 5-8°C / min, and keeping warm for 20 minutes; then heating to 2500-2700°C at a heating rate of 5-8°C / min, and keeping warm for 20 minutes.

9. The radiation-proof graphite heat dissipation film according to claim 4, characterized in that: In S2, during the process of the graphene layer being adhered to the shielding metal grid (4), the substrate is heated, and the heating temperature range is 40° C. to 80° C.

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