A graphene thermal conductive pad and preparation method thereof

Abstract

The present invention discloses a graphene thermally conductive gasket and a preparation method thereof, wherein the thermally conductive gasket comprises graphene composite films stacked along the thickness direction, wherein the graphene composite films are bonded and stacked by adhesive; the graphene composite film comprises an adhesive tape and a graphene thermally conductive film bonded to the surface of the adhesive tape. Since the graphene composite film has good flexibility and thermal conductivity, and the graphene thermally conductive film on the surface of the adhesive tape is relatively thin, the adhesive is easy to penetrate and infiltrate, thereby enhancing the bonding force between the graphene layers. Therefore, the thermally conductive gasket obtained by cutting along the thickness direction is not prone to cracking caused by graphene delamination, and the elasticity enhanced by the adhesive tape substrate and the adhesive is obtained.

Description

Technical Field

[0001] The present invention relates to the technical field of thermal conductive materials, and in particular to a graphene thermal conductive gasket and a preparation method thereof. Background Art

[0002] Thermal pads are made of thermally conductive functional materials with a certain thermal conductivity and flexibility. They are mainly used to fill the gap between heating elements and radiators, reduce interfacial thermal resistance, and improve the transfer efficiency of excess heat generated by electronic devices during operation. They are widely used in electronic devices such as 5G base stations, laptops, and high-power LED displays. With the substantial increase in the power of electronic devices, ordinary thermal pads (thermal conductivity below 10W / (m·K)) are far from meeting the heat dissipation requirements.

[0003] Graphene is a two-dimensional material with ultra-high thermal conductivity. Macroscopic sheets formed by orderly stacking graphene have shown great application prospects in the field of thermal interface materials. Among them, the use of ordered graphene films and polymer organic composite layers stacked and bonded, and then cut into thermal conductive pads is currently recognized as one of the main ways to obtain high vertical thermal conductivity thermal interface materials, such as patent documents CN113290958A and CN113183544A.

[0004] Although the gasket prepared in the above manner has a high thermal conductivity, since there is only a weak van der Waals force between the graphene sheets, the thermally conductive gasket obtained by cutting after the graphene sheets are compounded with organic matter is prone to cracking and fragility due to the delamination of the graphene sheets. In addition, graphene itself is a hard material, and the gasket prepared is often hard and inelastic, which seriously restricts the application of graphene in the field of high-performance thermal interface materials. Summary of the invention

[0005] One purpose of the present solution is to provide a graphene thermally conductive gasket, in which graphene sheets are vertically stacked, the prepared thermally conductive gasket has no cracks, the stacked structure is not damaged, and has a complete structure and good compression resilience.

[0006] Another object of the present invention is to provide a method for preparing the above-mentioned graphene thermal conductive gasket.

[0007] To achieve the above objectives, this plan is as follows:

[0008] A graphene thermally conductive gasket, comprising graphene composite films stacked along a thickness direction, wherein the graphene composite films are stacked and bonded by an adhesive;

[0009] The graphene composite film comprises an adhesive tape and a graphene thermal conductive film adhered to the surface of the adhesive tape.

[0010] Preferably, the content of the graphene thermally conductive film in the thermally conductive gasket accounts for 20wt.% to 90wt.% of the total weight of the thermally conductive gasket, and preferably the content of the graphene thermally conductive film in the thermally conductive gasket accounts for 40wt.% to 60wt.% of the total weight of the thermally conductive gasket;

[0011] The content of the adhesive tape in the thermally conductive pad accounts for 5wt.% to 60wt.% of the total weight of the thermally conductive pad, and preferably the content of the adhesive tape in the thermally conductive pad accounts for 30wt.% to 50wt.% of the total weight of the thermally conductive pad;

[0012] The content of the adhesive in the thermally conductive gasket accounts for 5wt.% to 50wt.% of the total weight of the thermally conductive gasket, and preferably the content of the adhesive in the thermally conductive gasket accounts for 10wt.% to 30wt.% of the total weight of the thermally conductive gasket.

[0013] If the proportion of graphene thermal conductive film is less than 20wt.%, the thermal conductivity of the thermal conductive gasket will be reduced; if the proportion of graphene thermal conductive film is greater than 90wt.%, the thermal conductive gasket will be difficult to form and will have poor compression rebound performance; if the proportion of tape is less than 5wt.%, the adhesive effect of the tape will be poor, the gasket will be easy to crack, and the compression rebound performance will be poor; if the proportion of tape is greater than 60wt.%, the thermal conductivity of the gasket will be poor; if the proportion of adhesive is less than 5wt.%, the gasket will be easy to crack; if the proportion of adhesive is greater than 50wt.%, the thermal conductivity of the gasket will be reduced.

[0014] Preferably, the adhesive tape is one or more of single-sided adhesive tape, double-sided adhesive tape and foam adhesive tape; preferably, the adhesive tape is double-sided adhesive tape;

[0015] The thickness of the adhesive tape is 5 to 100 μm; preferably, the thickness of the adhesive tape is 10 to 50 μm.

[0016] If the thickness of the tape is less than 5 μm, wrinkles are likely to form, making it difficult to fully adhere to the graphene, the gasket is prone to cracking, and the compression resilience is poor; if the thickness of the tape is greater than 100 μm, the flexibility of the tape decreases and the compression resilience performance of the gasket decreases.

[0017] Preferably, both side surfaces of the double-sided tape are bonded with graphene thermal conductive films or one side surface of the double-sided tape is bonded with graphene thermal conductive films.

[0018] Preferably, the thickness of the graphene thermally conductive film is 1 to 1000 μm, preferably the thickness of the graphene thermally conductive film is 10 to 100 μm, more preferably the thickness of the graphene thermally conductive film is 3 to 50 μm, and most preferably the thickness of the graphene thermally conductive film is 5 to 20 μm;

[0019] The graphene thermally conductive film is a calendered graphene thermally conductive film.

[0020] After the graphene thermally conductive film is bonded to the surface of the tape, the thickness of the graphene thermally conductive film can be reduced by peeling or grinding operations, and the thickness of the graphene thermally conductive film is controlled within the range of 3 to 50 μm, preferably 5 to 20 μm; if the thickness of the graphene film is less than 3 μm, a discontinuous graphene layer is easily formed on the bonding surface of the tape during the preparation process, thereby reducing the thermal conductivity of the gasket; if the thickness of the graphene thermally conductive film is greater than 50 μm, the composite film has poor flexibility and the resulting thermally conductive gasket has poor compression resilience.

[0021] Preferably, the adhesive includes one or more of epoxy resin, phenolic resin, furfural resin, polyurethane, acrylic resin and silicone adhesive; the adhesive is preferably silicone; the silicone is liquid silicone; the liquid silicone includes one or more of polydimethylcyclosiloxane, polydimethylsiloxane, α, ω-dihydroxypolydimethylsiloxane, polydiphenylsiloxane, α, ω-dihydroxypolymethyl (3,3,3-trifluoropropyl) siloxane, cyanosiloxysilane and α, ω-diethylpolydimethylsiloxane.

[0022] In a second aspect, a method for preparing the graphene thermally conductive pad as described above is provided, the method comprising the following steps:

[0023] The graphene thermal conductive film is bonded to the surface of the tape to obtain a graphene composite film;

[0024] Adhesively stacking the graphene composite films along a thickness direction;

[0025] The bonded and stacked graphene composite films are cut along the thickness direction to obtain a graphene thermally conductive gasket.

[0026] Preferably, the method further comprises: treating the graphene thermally conductive film bonded to the surface of the tape to reduce the thickness of the graphene thermally conductive film bonded to the surface of the tape;

[0027] The treatment comprises a grinding operation or a stripping operation;

[0028] The grinding operation includes manual grinding or mechanical grinding;

[0029] The peeling operation includes direct peeling or tape peeling.

[0030] Preferably, the method further comprises: pressing the bonded and stacked graphene composite films into blocks.

[0031] Preferably, the graphene composite films bonded and stacked along the thickness direction are bonded and stacked by an adhesive; the bonding and stacking is performed by dipping bonding, coating bonding or hot melt bonding; preferably, the bonding and stacking is performed by coating bonding;

[0032] The cutting is performed after the bonded and stacked graphene composite films are cured and formed; the curing and forming includes curing by heating or curing at room temperature; when heating and curing, the curing temperature ranges from 50 to 200° C., and preferably the curing temperature is 80 to 150° C.

[0033] The curing temperature is selected according to the properties of the adhesive. When heating curing is adopted, the temperature range is 50-200°C, preferably 80-150°C. If the temperature is lower than 50°C, the adhesive will not be completely cured and the thermal gasket will be prone to cracking. If the temperature is higher than 200°C, the curing reaction will be too intense and bubbles may be generated in the adhesive, which will reduce the thermal conductivity of the gasket. It may also cause the degree of polymerization and cross-linking of the adhesive to be too high, increase the hardness, and reduce the compression resilience of the thermal gasket.

[0034] The beneficial effects of this program are as follows:

[0035] 1. The prepared graphene composite film has ultra-high flexibility, so the thermal conductive gasket has good compression resilience;

[0036] 2. Graphene is highly oriented along the thickness direction, with high thermal conductivity and low application thermal resistance;

[0037] 3. The graphene sheets have strong bonding strength between layers, and the thermal pad is not easy to crack;

[0038] 4. The defective graphene film and scraps can be reused. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the implementation of the present scheme, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present scheme. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0040] Figure 1 This is a diagram showing the graphene composite film prepared in Example 1;

[0041] Figure 2 The graphene composite film obtained in Example 1 is stacked to form a block;

[0042] Figure 3 This is a diagram showing the graphene thermal conductive gasket prepared in Example 1. DETAILED DESCRIPTION

[0043] The implementation method of this solution is further described in detail below. Obviously, the described embodiments are only part of the embodiments of this solution, rather than an exhaustive list of all the embodiments. It should be noted that the embodiments and features in the embodiments of this solution can be combined with each other without conflict.

[0044] Taking the direction perpendicular to the plane on which the graphene thermal conductive film is laid as the thickness direction, the inventor of the present application provides a graphene thermal conductive gasket, which is composed of a graphene composite film and an adhesive stacked along the thickness direction; wherein the graphene composite film includes a tape and a graphene thermal conductive film bonded to the surface of the tape; after the graphene thermal conductive film is bonded to the surface of the tape, the thickness of the bonded graphene thermal conductive film can be reduced by peeling, grinding, etc.; the graphene in the graphene thermal conductive film bonded to the surface of the tape is highly oriented, and the formed graphene composite film has good flexibility and thermal conductivity. The formed flexible graphene composite film is bonded and stacked. At this time, since the graphene thermal conductive film on the surface of the tape is relatively thin, the adhesive is easy to penetrate and infiltrate, which enhances the bonding force between the graphene layers; after stacking, it is pressed into a block and cured; cut along the thickness direction to obtain an elastic thermal conductive gasket. The gasket is not prone to cracking caused by graphene delamination, and obtains the elasticity enhanced by the tape substrate and the adhesive.

[0045] The graphene composite film formed in this scheme has good flexibility, which is mainly reflected in its bendability and curling. Figure 1 The composite film shown has wrinkles on its surface after being bent or curled, but its structure and continuity are not damaged; whereas, ordinary brittle graphene films that are not combined with tape will crack or delaminate after being bent or curled many times, and their structure will be damaged. In the present scheme, when preparing a thermally conductive gasket, a graphene composite film is prepared by bonding a graphene thermally conductive film with tape. The prepared graphene composite film has better flexibility than various graphene thermally conductive films. During the preparation process, a highly oriented graphene thermally conductive film is bonded with tape, and the graphene bonded to the tape is peeled off and ground. After peeling off and grinding, the graphene is still highly oriented and continuous. The thickness of the graphene thermally conductive film layer is reduced by grinding, peeling off, etc., and the adhesive is easier to penetrate when bonding and stacking. The infiltration of the graphene layer enhances the bonding force between the graphene sheets; and this solution has low requirements on the specifications and quality of the graphene thermal conductive film used, that is, this solution only has requirements on the surface flatness of the graphene film, that is, the bonding requirements between the film and the tape, and finally only the surface layer of the raw graphene film exists on the surface of the tape, so defective products or scraps with uneven density and unqualified size can also be fully utilized, and even the thermal conductivity of the defective graphene film raw material (thermal conductivity coefficient> 100W / (m·K)) can meet the use requirements. A method for preparing a graphene thermal conductive gasket, the method comprising the following steps:

[0046] a. The graphene thermal conductive film is bonded to the surface of the tape;

[0047] b. reducing the thickness of the graphene thermal conductive film bonded to the surface of the tape by grinding, peeling, etc. to obtain a graphene composite film;

[0048] c. bonding the stacked graphene composite films with an adhesive along the thickness direction;

[0049] d. Pressing into blocks and solidifying into shape;

[0050] e. Cut into several pieces along the thickness direction to obtain graphene thermal conductive pads.

[0051] In this solution, the direction perpendicular to the plane on which the graphene thermal conductive film is laid is taken as the thickness direction.

[0052] In one embodiment, the content of graphene thermally conductive film in the prepared graphene thermally conductive gasket accounts for 20wt.% to 90wt.% of the total weight of the thermally conductive gasket, and preferably, the content of graphene thermally conductive film in the thermally conductive gasket accounts for 40wt.% to 60wt.% of the total weight of the thermally conductive gasket, such as 20wt.%, 25wt.%, 30wt.%, 35wt.%, 40wt.%, 45wt.%, 50wt.%, 55wt.%, 60wt.%, 65wt.%, 70wt.%, 75wt.%, 80wt.%, 85wt.% or 90wt.%.

[0053] If the proportion of graphene thermal conductive film in the graphene thermal conductive gasket is less than 20wt.%, the thermal conductivity of the thermal conductive gasket will be reduced; if the proportion of graphene thermal conductive film is greater than 90wt.%, the thermal conductive gasket will be difficult to form and have poor compression rebound performance.

[0054] In one embodiment, the content of tape in the prepared graphene thermal gasket accounts for 5wt.% to 60wt.% of the total weight of the thermal gasket, and preferably the content of tape in the thermal gasket accounts for 30wt.% to 50wt.% of the total weight of the thermal gasket, such as 5wt.%, 10wt.%, 15wt.%, 20wt.%, 25wt.%, 30wt.%, 35wt.%, 40wt.%, 45wt.%, 50wt.%, 55wt.% or 60wt.%.

[0055] If the proportion of tape in the graphene thermal conductive gasket is less than 5wt.%, the adhesive effect of the tape is poor, the gasket is prone to cracking, and the compression resilience is poor; if the proportion of tape is greater than 60wt.%, the thermal conductivity of the gasket is poor.

[0056] In one embodiment, the content of adhesive in the prepared graphene thermal gasket accounts for 5wt.% to 50wt.% of the total weight of the thermal gasket, and preferably the content of adhesive in the thermal gasket accounts for 10wt.% to 30wt.% of the total weight of the thermal gasket, such as 5wt.%, 10wt.%, 15wt.%, 20wt.%, 25wt.%, 30wt.%, 35wt.%, 40wt.%, 45wt.% or 50wt.%.

[0057] If the proportion of adhesive in the graphene thermally conductive gasket is less than 5wt.%, the gasket is prone to cracking; if the proportion of adhesive is greater than 50wt.%, the thermal conductivity of the gasket is reduced.

[0058] In one embodiment, the tape can be a single-sided tape, a double-sided tape, a foam tape, etc., preferably a double-sided tape. The double-sided tape can be bonded to graphene on both sides or on one side. Preferably, the double-sided tape is used to bond graphene on both sides.

[0059] In another embodiment, the tape thickness is 5 to 100 μm, and preferably the tape thickness is 10 to 50 μm, such as 5 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, 75 μm, 80 μm, 85 μm, 90 μm, 95 μm or 100 μm.

[0060] If the thickness of the tape is less than 5 μm, wrinkles are likely to form, making it difficult to fully adhere to the graphene, the gasket is prone to cracking, and the compression resilience is poor; if the thickness of the tape is greater than 100 μm, the flexibility of the tape decreases and the compression resilience performance of the gasket decreases.

[0061] In one embodiment, the adhesive (including the adhesive in the tape) can be selected from epoxy resin, phenolic resin, furfural resin, polyurethane, acrylic resin, silicone rubber, etc.; from the perspectives of compressibility, compression resilience, hardness and filling effect, silicone rubber is preferred; liquid silicone rubber is preferred among silicone rubbers; the liquid silicone rubber used can be selected from one or more of polydimethylcyclosiloxane, polydimethylsiloxane, α, ω-dihydroxypolydimethylsiloxane, polydiphenylsiloxane, α, ω-dihydroxypolymethyl (3,3,3-trifluoropropyl) siloxane, cyanosiloxysilane and α, ω-diethylpolydimethylsiloxane.

[0062] In one embodiment, the graphene thermally conductive film in step a is preferably a calendered graphene thermally conductive film.

[0063] In one embodiment, the thickness of the graphene thermal conductive film is 1 to 1000 μm, preferably 10 to 100 μm, such as 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, 55 μm, 60μm, 65μm, 70μm, 75μm, 80μm, 85μm, 90μm, 95μm, 100μm, 100μm, 150μm, 200μm, 250μm, 300μm, 350 μm, 400μm, 450μm, 500μm, 550μm, 600μm, 650μm, 700μm, 750μm, 800μm, 850μm, 900μm, 950μm or 1000μm.

[0064] The thickness of the graphene thermally conductive film is reduced through step b, and the thickness of the graphene thermally conductive film is controlled within the range of 3 to 50 μm, preferably within the range of 5 to 20 μm; if the thickness of the graphene thermally conductive film is less than 3 μm, a discontinuous graphene layer is easily formed on the adhesive surface of the tape during the preparation process, thereby reducing the thermal conductivity of the gasket; if the thickness of the graphene thermally conductive film is greater than 50 μm, the prepared graphene composite film has poor flexibility, and the prepared thermally conductive gasket has poor compression resilience.

[0065] In one embodiment, the grinding operation in step b includes manual grinding, mechanical grinding and the like, and the stripping operation includes direct stripping, tape bonding stripping and the like.

[0066] In one embodiment, the specific method of bonding and stacking in step c includes dipping, coating bonding, hot melt bonding, etc., and the preferred method of bonding and stacking is coating bonding.

[0067] In one embodiment, the curing in step d can be heat curing or room temperature curing. If heat curing is selected, the curing temperature needs to be selected according to the properties of the adhesive. The temperature range of heat curing is 50 to 200°C, and the preferred temperature range is 80 to 150°C, such as 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, 180°C, 190°C or 200°C.

[0068] If the curing temperature is lower than 50°C, the adhesive may not be fully cured and the thermal gasket may crack. If the curing temperature is higher than 200°C, the curing reaction will be too intense and bubbles may be generated in the adhesive, reducing the thermal conductivity of the gasket. It may also cause the adhesive to polymerize and cross-link to a high degree, increase the hardness, and reduce the compression resilience of the thermal gasket.

[0069] In one embodiment, there is no special restriction on the cutting method in step e, and the cutting method may include wire cutting, laser cutting, ultrasonic cutting, blade cutting, cryo-cutting, vibration cutting, ultrasonic-cryo-cutting, etc. There is no special requirement on the thickness of the slices, and the slices may be cut according to specific needs, such as 0.25 to 5 mm; they may also be cut into thinner sheets, such as 0.05 to 0.25 mm, etc.

[0070] The present solution is described below through specific embodiments.

[0071] In the following embodiments and comparative examples, liquid silicone is used as an adhesive for bonding and stacking to prepare thermally conductive gaskets. In order to reflect the comparative effect, the thickness of the slices in the following embodiments and comparative examples is 1 mm, and the application thermal resistance and compression resilience thereof are tested;

[0072] A graphene thermal conductive pad, the preparation process of which is as follows:

[0073] a. The graphene thermal conductive film is bonded to the surface of the tape;

[0074] b. reducing the thickness of the graphene thermal conductive film bonded to the surface of the tape by grinding, peeling, etc. to obtain a graphene composite film;

[0075] c. bonding the stacked graphene composite films with an adhesive along the thickness direction;

[0076] d. Pressing into blocks and solidifying into shape;

[0077] e. Cut into several pieces along the thickness direction to obtain graphene thermal conductive pads.

[0078] The thermal conductivity and application thermal resistance of the thermal pad are tested at 20psi using ASTM D5470.

[0079] The compression resilience performance of the thermal conductive gasket under 30% strain condition is tested by ASTM D575.

[0080] In step b, the prepared graphene composite film has a certain flexibility, and in step e, thermal conductive gaskets of different sizes are cut out as needed.

[0081] Example 1

[0082] In this embodiment, a graphene thermally conductive gasket is prepared according to the above steps, and the amount of each raw material used in the preparation process, the thickness of the tape and the graphene thermally conductive film in the prepared graphene thermally conductive gasket, the bonding method between the graphene composite films, the type of liquid silicone selected as the adhesive, the curing temperature after stacking and bonding, the thickness of the prepared thermally conductive gasket, and the results of the thermal conductivity test of the gasket are shown in Table 1. The adhesive mentioned in this embodiment includes the adhesive used in the tape.

[0083] like Figures 1 to 3 The intermediate products obtained in different steps during the process of preparing the graphene thermal conductive gasket according to the above steps in Example 1, Figure 1 The flexible graphene composite film prepared in step b can be prepared by bonding graphene on both sides of a double-sided tape. Figure 2 The diagram shows the state of the prepared graphene composite films after being bonded and stacked in step c, and the stacked graphene composite films form a block. Figure 3 The obtained graphene thermal pad is shown in FIG.

[0084] Table 1

[0085]

[0086] Example 2

[0087] In this embodiment, a graphene thermally conductive gasket is prepared according to the above steps, and the amount of each raw material used in the preparation process, the thickness of the tape and the graphene thermally conductive film in the prepared graphene thermally conductive gasket, the bonding method between the graphene composite films, the type of liquid silicone selected as the adhesive, the curing temperature after stacking and bonding, the thickness of the prepared thermally conductive gasket, and the results of the thermal conductivity test of the gasket are shown in Table 2. The adhesive mentioned in this embodiment includes the adhesive used in the tape.

[0088] Table 2

[0089]

[0090] Example 3

[0091] In this embodiment, a graphene thermally conductive gasket is prepared according to the above steps, and the amount of each raw material used in the preparation process, the thickness of the tape and the graphene thermally conductive film in the prepared graphene thermally conductive gasket, the bonding method between the graphene composite films, the type of liquid silicone selected as the adhesive, the curing temperature after stacking and bonding, the thickness of the prepared thermally conductive gasket, and the results of the thermal conductivity test of the gasket are shown in Table 3. The adhesive mentioned in this embodiment includes the adhesive used in the tape.

[0092] Table 3

[0093]

[0094] Example 4

[0095] In this embodiment, a graphene thermally conductive gasket is prepared according to the above steps, and the amount of each raw material used in the preparation process, the thickness of the tape and the graphene thermally conductive film in the prepared graphene thermally conductive gasket, the bonding method between the graphene composite films, the type of liquid silicone selected as the adhesive, the curing temperature after stacking and bonding, the thickness of the prepared thermally conductive gasket, and the results of the thermal conductivity test of the gasket are shown in Table 4. The adhesive mentioned in this embodiment includes the adhesive used in the tape.

[0096] Table 4

[0097]

[0098] Example 5

[0099] In this embodiment, a graphene thermally conductive gasket is prepared according to the above steps, and the amount of each raw material used in the preparation process, the thickness of the tape and the graphene thermally conductive film in the prepared graphene thermally conductive gasket, the bonding method between the graphene composite films, the type of liquid silicone selected as the adhesive, the curing temperature after stacking and bonding, the thickness of the prepared thermally conductive gasket, and the results of the thermal conductivity test of the gasket are shown in Table 5. The adhesive mentioned in this embodiment includes the adhesive used in the tape.

[0100] Table 5

[0101]

[0102] Example 6

[0103] In this embodiment, a graphene thermally conductive gasket is prepared according to the above steps, and the amount of each raw material used in the preparation process, the thickness of the tape and the graphene thermally conductive film in the prepared graphene thermally conductive gasket, the bonding method between the graphene composite films, the type of liquid silicone selected as the adhesive, the curing temperature after stacking and bonding, the thickness of the prepared thermally conductive gasket, and the results of the thermal conductivity test of the gasket are shown in Table 6. The adhesive mentioned in this embodiment includes the adhesive used in the tape.

[0104] Table 6

[0105]

[0106] Example 7

[0107] In this embodiment, a graphene thermally conductive gasket is prepared according to the above steps, and the amount of each raw material used in the preparation process, the thickness of the tape and the graphene thermally conductive film in the prepared graphene thermally conductive gasket, the bonding method between the graphene composite films, the type of liquid silicone selected as the adhesive, the curing temperature after stacking and bonding, the thickness of the prepared thermally conductive gasket, and the results of the thermal conductivity test of the gasket are shown in Table 7. The adhesive mentioned in this embodiment includes the adhesive used in the tape.

[0108] Table 7

[0109]

[0110] Example 8

[0111] In this embodiment, a graphene thermally conductive gasket is prepared according to the above steps, and the amount of each raw material used in the preparation process, the thickness of the tape and the graphene thermally conductive film in the prepared graphene thermally conductive gasket, the bonding method between the graphene composite films, the type of liquid silicone selected as the adhesive, the curing temperature after stacking and bonding, the thickness of the prepared thermally conductive gasket, and the results of the thermal conductivity test of the gasket are shown in Table 8. The adhesive mentioned in this embodiment includes the adhesive used in the tape.

[0112] Table 8

[0113]

[0114] Comparative Example 1

[0115] In this comparative example, the steps of preparing the graphene thermally conductive gasket are the same as those in each embodiment, the amount of each raw material used in the preparation process, the thickness of the tape and the graphene thermally conductive film in the prepared graphene thermally conductive gasket, the bonding method between the graphene composite films, the type of liquid silicone selected as the adhesive, the curing temperature after stacking and bonding, the thickness of the prepared thermally conductive gasket, and the results of the thermal conductivity test of the gasket are shown in Table 9. The adhesive mentioned in this comparative example includes the adhesive used in the tape.

[0116] Table 9

[0117]

[0118] Comparative Example 2

[0119] In this comparative example, the steps of preparing the graphene thermally conductive gasket are the same as those in each embodiment, the amount of each raw material used in the preparation process, the thickness of the tape and the graphene thermally conductive film in the prepared graphene thermally conductive gasket, the bonding method between the graphene composite films, the type of liquid silicone selected as the adhesive, the curing temperature after stacking and bonding, the thickness of the prepared thermally conductive gasket, and the results of the thermal conductivity test of the gasket are shown in Table 10. The adhesive mentioned in this comparative example includes the adhesive used in the tape.

[0120] Table 10

[0121]

[0122] Comparative Example 3

[0123] In this comparative example, the steps of preparing the graphene thermally conductive gasket are the same as those in each embodiment, the amount of each raw material used in the preparation process, the thickness of the tape and the graphene thermally conductive film in the prepared graphene thermally conductive gasket, the bonding method between the graphene composite films, the type of liquid silicone selected as the adhesive, the curing temperature after stacking and bonding, the thickness of the prepared thermally conductive gasket, and the results of the thermal conductivity test of the gasket are shown in Table 11. The adhesive mentioned in this comparative example includes the adhesive used in the tape.

[0124] Table 11

[0125]

[0126] Comparative Example 4

[0127] In this comparative example, the steps of preparing the graphene thermally conductive gasket are the same as those in each embodiment, the amount of each raw material used in the preparation process, the thickness of the tape and the graphene thermally conductive film in the prepared graphene thermally conductive gasket, the bonding method between the graphene composite films, the type of liquid silicone selected as the adhesive, the curing temperature after stacking and bonding, the thickness of the prepared thermally conductive gasket, and the results of the thermal conductivity test of the gasket are shown in Table 12. The adhesive mentioned in this comparative example includes the adhesive used in the tape.

[0128] Table 12

[0129]

[0130] Comparative Example 5

[0131] In this comparative example, the steps of preparing the graphene thermally conductive gasket are the same as those in each embodiment, the amount of each raw material used in the preparation process, the thickness of the tape and the graphene thermally conductive film in the prepared graphene thermally conductive gasket, the bonding method between the graphene composite films, the type of liquid silicone selected as the adhesive, the curing temperature after stacking and bonding, the thickness of the prepared thermally conductive gasket, and the results of the thermal conductivity test of the gasket are shown in Table 13. The adhesive mentioned in this comparative example includes the adhesive used in the tape.

[0132] Table 13

[0133]

[0134] Comparative Example 6

[0135] In this comparative example, the steps of preparing the graphene thermally conductive gasket are the same as those in each embodiment, the amount of each raw material used in the preparation process, the thickness of the tape and the graphene thermally conductive film in the prepared graphene thermally conductive gasket, the bonding method between the graphene composite films, the type of liquid silicone selected as the adhesive, the curing temperature after stacking and bonding, the thickness of the prepared thermally conductive gasket, and the results of the thermal conductivity test of the gasket are shown in Table 14. The adhesive mentioned in this comparative example includes the adhesive used in the tape.

[0136] Table 14

[0137]

[0138] Through the above-mentioned embodiments and comparative examples, it can be known that when the content of each component is within the range described in the claims, the thermal conductivity improves with the increase of graphene content; when the graphene is excessive, the gasket is easily damaged by pressure, which has a greater impact on the thermal conductivity; when the graphene content is too low, the tape and adhesive as the main body cannot provide good thermal conductivity; and the increase in the content of tape and adhesive in the gasket improves the compression resilience.

[0139] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the protection scope of the present invention.

Claims

1. A method for preparing a graphene thermally conductive pad, characterized in that: The method comprises the following steps: S1, bonding a graphene thermal conductive film to both sides of a double-sided tape, treating the graphene thermal conductive film bonded to the tape surface, reducing the thickness of the graphene thermal conductive film bonded to the tape surface, and controlling the thickness of the graphene thermal conductive film to be 10 μm, thereby obtaining a graphene composite film; The treatment comprises a grinding operation or a stripping operation; The grinding operation includes manual grinding or mechanical grinding; The stripping operation includes direct stripping or tape stripping; S2, bonding and stacking the graphene composite films along the thickness direction with an adhesive; and pressing the bonded and stacked graphene composite films into a block; S3, cutting the bonded and stacked graphene composite films along the thickness direction to obtain a graphene thermally conductive gasket; The cutting is performed after the bonded and stacked graphene composite films are cured and formed; the curing and forming is performed by heating and curing at a temperature of 150° C.; The content of the graphene thermally conductive film in the thermally conductive gasket accounts for 40wt.% of the total weight of the thermally conductive gasket; The content of the double-sided adhesive tape in the thermally conductive pad accounts for 40wt.% of the total weight of the thermally conductive pad; The content of the adhesive in the thermally conductive gasket accounts for 20wt.% of the total weight of the thermally conductive gasket; The thickness of the adhesive tape is 10 μm; The graphene thermally conductive film is a calendered graphene thermally conductive film; The adhesive is polydimethylsiloxane; The bonded stack is bonded by coating; The thickness of the thermally conductive pad is 1.0 mm; The thermal conductivity of the thermally conductive pad is 97.1 W / (m·K); The application thermal resistance of the thermally conductive pad is 0.216K·cm 2 / W; The compression resilience performance of the thermal conductive pad is 89%.

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