Composite heat-conducting gasket and preparation method thereof

Abstract

The invention provides a composite heat-conducting gasket and a preparation method thereof, and belongs to the technical field of heat conduction. According to the preparation method of the composite heat-conducting gasket, the first adhesive is arranged on one side of the graphene gasket, then the first adhesive is made to permeate into the multiple gaps of the graphene gasket in a standing mode, and then the first adhesive on the surface of the graphene gasket is wiped off; and finally, the graphene gasket and the metal sheet are compounded in a press fit mode, in the press fit process, the first adhesive in the multiple gaps of the graphene gasket is partially extruded out, the first adhesive remaining in the composite heat conduction gasket can be reduced, most of the first adhesive can be connected with the gaps of the graphene gasket and the metal sheet, and the heat conduction performance of the composite heat conduction gasket is improved. Therefore, the end surfaces, close to the metal sheet, of the plurality of graphene sheets of the graphene gasket can be in direct contact with the metal sheet, so that the prepared composite heat-conducting gasket has relatively high strength and relatively good heat-conducting property, and the reuse times of the composite heat-conducting gasket applied to a chip test are increased.

Description

Technical Field

[0001] The present application relates to the field of heat conduction technology, and in particular to a composite heat-conducting gasket and a preparation method thereof. Background Art

[0002] Graphene is a carbon atom in the form of sp 2 A single-layer two-dimensional honeycomb lattice structure material formed by hybrid orbitals. Due to its unique physical and chemical properties, graphene has received widespread attention in the field of materials science. Among them, graphene thermal pads are a material made using the high thermal conductivity of graphene and are widely used in thermal management of electronic devices. In existing technologies, graphene thermal pads are used in the field of chip testing. During repeated use, due to the poor strength of the graphene thermal pads themselves, they are very easy to break during the test process and may remain on the chip surface. Therefore, how to improve the strength of the graphene thermal pads has become the key to improving the reusability of the graphene thermal pads. Summary of the invention

[0003] The present application provides a composite thermally conductive gasket and a preparation method thereof, which has both high strength and good thermal conductivity.

[0004] The embodiment of the present application is implemented as follows:

[0005] In the first aspect, the present application example provides a method for preparing a composite thermally conductive gasket, which includes: preparing a graphene gasket, setting a first adhesive on one side of the graphene gasket, and making the side with the first adhesive face upward, standing still for at least 30 minutes, removing the first adhesive on the surface of the graphene gasket, and pressing a metal sheet on the side of the graphene gasket where the first adhesive is set.

[0006] The graphene gasket has a horizontal direction perpendicular to the thickness direction. The graphene gasket includes a plurality of graphene sheets stacked in sequence along the horizontal direction, and a gap is provided between any two adjacent graphene sheets.

[0007] The thickness of the metal sheet is 1 μm to 1000 μm.

[0008] In the above technical scheme, the composite thermally conductive gasket of the present application is composited with a graphene gasket and a metal sheet, wherein the thickness of the metal sheet is only 1 μm to 1000 μm, which can greatly reduce the interfacial thermal resistance between the graphene gasket and the aluminum sheet, reduce the thermal performance loss of the graphene gasket, and improve the thermal conductivity of the composite thermally conductive gasket; the graphene gasket includes a plurality of graphene sheets stacked in sequence in the horizontal direction, which not only has good thermal conductivity, but also has a gap between any two adjacent graphene sheets. The preparation method of the composite thermally conductive gasket of the present application first sets a first adhesive on one side of the graphene gasket, and then allows the first adhesive to penetrate into the multiple gaps in the graphene gasket by standing, and then wipes off the first adhesive on the surface of the graphene gasket, and finally composites the graphene gasket and the metal sheet by pressing, and during the pressing process, the first adhesive in the multiple gaps of the graphene gasket is partially squeezed out, thereby achieving the purpose of bonding the metal sheet. The preparation method of the composite thermally conductive gasket of the present application adopts a special bonding process, which can not only reduce the first adhesive remaining in the composite thermally conductive gasket, but also make the first adhesive distributed in a point-like or block-like manner, most of which connects the gaps of the graphene gasket and the metal sheet, so that the end faces of multiple graphene sheets of the graphene gasket close to the metal sheet can be in direct contact with the metal sheet, thereby making the prepared composite thermally conductive gasket have both higher strength and better thermal conductivity, thereby increasing its repeated use times in chip testing.

[0009] In some possible implementations, the thickness of the metal sheet is 5 μm to 50 μm.

[0010] In the above technical solution, by making the thickness of the metal sheet within the above range, it is beneficial to further reduce the interface thermal resistance between the graphene gasket and the aluminum sheet, reduce the thermal performance loss of the graphene gasket, and improve the thermal conductivity of the composite thermally conductive gasket.

[0011] In some possible embodiments, the metal sheet includes an aluminum sheet, a copper sheet, a nickel sheet, or an indium sheet;

[0012] Optionally, the metal sheet is an aluminum sheet.

[0013] In the above technical solution, selecting an aluminum sheet as the metal sheet can further improve the strength of the composite thermally conductive gasket, thereby increasing the number of times it can be reused in chip testing.

[0014] In some possible implementation schemes, the viscosity of the first adhesive is ≤100 mpa*S.

[0015] In the above technical solution, the first adhesive with a viscosity of ≤100 mpa*S has good permeability, which is conducive to the first adhesive penetrating into the gaps between the graphene sheets during the static process.

[0016] In some possible implementation schemes, the first adhesive is an organic silicone adhesive.

[0017] In some possible embodiments, the method of removing the first adhesive on the surface of the graphene gasket includes wiping it with oil-absorbing paper.

[0018] In some possible embodiments, the method of laminating the metal sheet and the graphene gasket includes:

[0019] The metal sheet and the graphene gasket are pressed together using a pressing device, the pressing temperature is 50° C. to 150° C., the pressing pressure is 1 MPa to 100 MPa, and the pressing time is 5 min to 20 min.

[0020] In some possible embodiments, the thickness of the graphene gasket is 0.1 mm to 5 mm;

[0021] Optionally, the thickness of the graphene gasket is 0.1 mm to 1 mm.

[0022] In some possible implementation schemes, two adjacent graphene sheets are bonded with a second adhesive, and the second adhesive is distributed in an island shape.

[0023] In the above technical solution, the second adhesive distributed in an island shape can not only bond multiple graphene sheets to each other, but also will not have a significant impact on the overall thermal conductivity of the graphene gasket.

[0024] In a second aspect, the present application example provides a composite thermally conductive gasket, which is prepared according to the preparation method of the composite thermally conductive gasket in the above embodiment.

[0025] In the above technical solution, the composite thermally conductive gasket of the present application has both high strength and good thermal conductivity, which increases the number of times it can be reused in chip testing. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 This is a schematic diagram of the structure of a composite thermally conductive gasket according to an embodiment of the present application;

[0028] Figure 2 for Figure 1 A magnified view of region A;

[0029] Figure 3 for Figure 1Magnified view of area B.

[0030] Icon: 10 - composite thermal conductive gasket; 100 - graphene gasket; 110 - graphene sheet; 120 - second bonding block; 200 - bonding layer; 210 - first bonding block; 300 - metal sheet. DETAILED DESCRIPTION

[0031] The embodiments of the present application will be described in detail below in conjunction with the examples, but it will be appreciated by those skilled in the art that the following examples are only used to illustrate the present application and should not be considered as limiting the scope of the present application. In the examples, if specific conditions are not specified, they are carried out according to normal conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0032] Metal material is also a commonly used thermal conductive material with good thermal conductivity and processing performance. The present application considers that if metal material and graphene gasket are combined to form a composite thermal conductive gasket, the mechanical strength of the graphene gasket and the number of times it can be reused in chip testing may be improved.

[0033] However, due to the different materials of the metal material and the graphene gasket and the existence of a composite interface, this will lead to a large interface thermal resistance between the metal material and the graphene gasket, and cause a large loss of thermal performance of the graphene gasket, resulting in poor thermal conductivity of the composite thermally conductive gasket.

[0034] Based on this, the present application provides a method for preparing a composite thermally conductive gasket, which comprises the following steps:

[0035] S1. Prepare graphene gasket

[0036] The graphene gasket has a horizontal direction perpendicular to the thickness direction. The graphene gasket includes a plurality of graphene sheets stacked in sequence along the horizontal direction, and a gap is provided between any two adjacent graphene sheets.

[0037] The thickness of the graphene gasket is 0.1 mm to 5 mm.

[0038] As an example, the thickness of the graphene spacer may be 0.1 mm, 0.2 mm, 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, or 5 mm.

[0039] Optionally, the thickness of the graphene gasket is 0.1 mm to 1 mm.

[0040] Two adjacent graphene sheets are bonded with a second adhesive, and the second adhesive is distributed in an island shape. The second adhesive distributed in an island shape can not only bond multiple graphene sheets to each other, but also will not affect the overall thermal conductivity of the graphene gasket too much.

[0041] The graphene gasket of the present application can be purchased from the market or can be homemade. The present application provides a method for preparing the graphene gasket, comprising the following steps:

[0042] A dot-shaped acrylic resin adhesive is sprayed on the first graphene film, and then the second graphene film is aligned and placed on the first graphene film, and a layer of acrylic resin adhesive is further coated on the second graphene film, and then the third graphene film is stacked, and this process is repeated back and forth until the target height is reached to obtain a graphene film block; the graphene film block is sliced ​​along the direction of the graphene film stacking by laser cutting to obtain a graphene gasket.

[0043] S2. Setting the first adhesive

[0044] Place the graphene gasket under the spraying equipment, use the spraying equipment to spray the first adhesive on one surface of the graphene gasket, and make the side with the first adhesive face upward, let it stand for at least 30 minutes, and then remove the first adhesive on the surface of the graphene gasket.

[0045] Optionally, the viscosity of the first adhesive is ≤100 mpa*S. The first adhesive with a viscosity of ≤100 mpa*S has good permeability, which is conducive to the first adhesive penetrating into the gaps between the graphene sheets during the static process.

[0046] Optionally, the first adhesive is an organic silicone adhesive.

[0047] As an example, the standing time may be 30 min, 60 min, 90 min, 120 min, 150 min or 180 min.

[0048] Optionally, the method of removing the first adhesive on the surface of the graphene gasket includes wiping it with oil-absorbing paper.

[0049] S3, Pressing

[0050] Prepare a metal sheet, place the graphene gasket and the metal sheet on a clean workbench respectively, and then use a high-precision positioning device to overlap the graphene gasket and the metal sheet so that the side of the graphene gasket where the first adhesive is set is in contact with the metal sheet, and then align them so that they are completely aligned in length and width directions. Finally, use a pressing device to apply a certain amount of pressure between the graphene gasket and the metal sheet to make them tightly combined to obtain a composite thermal conductive gasket.

[0051] The thickness of the metal sheet is 1 μm to 1000 μm.

[0052] As an example, the thickness of the metal sheet may be 1 μm, 2 μm, 5 μm, 10 μm, 50 μm, 100 μm, 200 μm, 300 μm, 400 μm, 500 μm, 600 μm, 700 μm, 800 μm, 900 μm or 1000 μm.

[0053] Optionally, the thickness of the metal sheet is 5 μm to 50 μm.

[0054] Optionally, by making the thickness of the metal sheet within the above range, it is helpful to further reduce the interface thermal resistance between the graphene gasket and the aluminum sheet, reduce the thermal performance loss of the graphene gasket, and improve the thermal conductivity of the composite thermally conductive gasket.

[0055] The metal sheet includes an aluminum sheet, a copper sheet, a nickel sheet or an indium sheet.

[0056] Optionally, the metal sheet is an aluminum sheet.

[0057] Selecting an aluminum sheet as the metal sheet can further improve the strength of the composite thermal conductive gasket, thereby increasing the number of times it can be reused in chip testing.

[0058] Optionally, the pressing temperature is 50° C. to 150° C., the pressing pressure is 1 MPa to 100 MPa, and the pressing time is 5 min to 20 min.

[0059] As an example, the pressing temperature can be 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C or 150°C, the pressing pressure can be 1MPa, 2MPa, 5MPa, 10MPa, 20MPa, 30MPa, 40MPa, 50MPa, 60MPa, 70MPa, 80MPa, 90MPa or 100MPa, and the pressing time can be 5min, 10min, 15min or 20min.

[0060] The composite thermally conductive gasket of the present application is composited with a graphene gasket and a metal sheet, wherein the thickness of the metal sheet is only 1 μm to 1000 μm, which can greatly reduce the interfacial thermal resistance between the graphene gasket and the aluminum sheet, reduce the thermal performance loss of the graphene gasket, and improve the thermal conductivity of the composite thermally conductive gasket; the graphene gasket includes a plurality of graphene sheets stacked in sequence in the horizontal direction, which not only has good thermal conductivity, but also has a gap between any two adjacent graphene sheets. The preparation method of the composite thermally conductive gasket of the present application first sets a first adhesive on one side of the graphene gasket, then allows the first adhesive to penetrate into the multiple gaps in the graphene gasket by standing, then wipes off the first adhesive on the surface of the graphene gasket, and finally composites the graphene gasket and the metal sheet by pressing. During the pressing process, the first adhesive in the multiple gaps of the graphene gasket is partially squeezed out, thereby achieving the purpose of bonding the metal sheet. The preparation method of the composite thermally conductive gasket of the present application adopts a special bonding process, which can not only reduce the first adhesive remaining in the composite thermally conductive gasket, but also make the first adhesive distributed in a point-like or block-like manner, most of which connects the gaps of the graphene gasket and the metal sheet, so that the end faces of multiple graphene sheets of the graphene gasket close to the metal sheet can be in direct contact with the metal sheet, thereby making the prepared composite thermally conductive gasket have both high strength and good thermal conductivity, thereby increasing its number of repeated uses in chip testing, reducing the testing cost of chips or power devices, and improving the problem of residual graphene gasket at the chip testing end.

[0061] The composite thermally conductive gasket of the present application can be widely used in application fields such as electronic equipment heat dissipation management, material recycling, and research and development of high-performance thermally conductive materials. First, in the field of electronic equipment heat dissipation management, the composite thermally conductive gasket of the present application can greatly improve the performance of repeated use tests, reduce interface thermal resistance, and improve thermal conductivity, which is of great significance for solving the heat dissipation problems that are prevalent in current electronic equipment; and as electronic equipment develops towards high performance, miniaturization and integration, the heat dissipation problem is becoming increasingly prominent, and the application prospects of this technical solution are broad. Secondly, in the field of material recycling, the composite thermally conductive gasket of the present application is a detachable design, which can realize the reuse of graphene gaskets, reduce resource waste, and reduce production costs. This is of great significance for promoting the development of material recycling technology and achieving sustainable development. With the improvement of environmental awareness and the increasingly serious problem of resource shortage, the demand for material recycling technology is increasing, and the application prospects of this technical solution are broad. Finally, in the field of high-performance thermal conductive material research and development, the composite thermal conductive gasket of this application can give full play to the thermal conductivity of graphene and improve thermal conductivity efficiency, which is of great significance for the research and development of higher-performance thermal conductive materials and meeting the requirements of high-end electronic equipment for heat dissipation performance. With the development of high-end electronic equipment, the demand for high-performance thermal conductive materials is increasing, and the application prospects of this technical solution are broad. In general, the composite thermal conductive gasket of this application has broad application prospects and large market demand, and is expected to play an important role in the fields of electronic equipment heat dissipation management, material recycling, and high-performance thermal conductive material research and development.

[0062] The present application also provides a composite thermally conductive gasket, which is prepared according to the preparation method of the composite thermally conductive gasket in the above embodiment.

[0063] See also Figure 1 The composite thermally conductive gasket 10 includes a graphene gasket 100 , an adhesive layer 200 , and a metal sheet 300 which are sequentially stacked in a thickness direction.

[0064] Among them, see Figure 2 The graphene gasket 100 is a thermally conductive gasket made of a raw material including graphene, and has a horizontal direction perpendicular to the thickness direction. The graphene gasket 100 includes a plurality of graphene sheets 110 stacked in sequence along the horizontal direction, and there is a gap between any two adjacent graphene sheets 110.

[0065] Optionally, two adjacent graphene sheets 110 are bonded together by a plurality of second bonding blocks 120 , and the plurality of second bonding blocks 120 are distributed in an island shape.

[0066] See also Figure 1 and 3 The adhesive layer 200 is a layered structure connecting the graphene gasket 100 and the metal sheet 300, and its thickness is ≤5 μm.

[0067] Optionally, the adhesive layer 200 includes a plurality of first adhesive blocks 210 distributed in an island shape, and the plurality of first adhesive blocks 210 distributed in an island shape are used to connect the graphene gasket 100 and the metal sheet 300, so that the end surfaces of the plurality of graphene sheets 110 of the graphene gasket 100 close to the metal sheet 300 and many areas where the first adhesive blocks 210 are not set can be in direct contact with the metal sheet 300, thereby making the prepared composite thermally conductive gasket 10 have both higher strength and better thermal conductivity, thereby increasing the number of times it can be reused in chip testing.

[0068] Optionally, the first bonding block 210 includes organic silicone adhesive.

[0069] The metal sheet 300 is a sheet-like structure made of metal material, and has a thickness of 1 μm to 1000 μm.

[0070] The metal sheet 300 includes an aluminum sheet, a copper sheet, a nickel sheet or an indium sheet.

[0071] Optionally, the metal sheet 300 is an aluminum sheet.

[0072] See also Figure 3 The graphene sheet 110 includes a large surface close to an adjacent graphene sheet 110 , one end of the first bonding block 210 is connected to the metal sheet 300 , and the other end is connected to the large surface of the graphene sheet 110 and / or the second bonding block 120 .

[0073] The two ends of the first bonding block 210 are used to respectively connect the large surfaces of the metal sheet 300 and the graphene sheet 110 and / or the second bonding block 120, so that the end surfaces of the multiple graphene sheets 110 of the graphene gasket 100 close to the metal sheet 300 can directly contact the metal sheet 300, thereby making the prepared composite thermally conductive gasket 10 have both higher strength and better thermal conductivity, thereby increasing the number of times it can be reused in chip testing.

[0074] The following is a further detailed description of a composite thermally conductive gasket and a preparation method thereof of the present application in conjunction with embodiments.

[0075] Example 1

[0076] The present invention provides a composite thermally conductive pad and a method for preparing the same, which comprises the following steps:

[0077] S1. Prepare graphene gasket

[0078] A dot-shaped acrylic resin adhesive is sprayed on the first layer of graphene film, and then the second layer of graphene film is aligned and placed on the first layer of graphene film, and a layer of acrylic resin adhesive is further coated on the second layer of graphene film, and then the third layer of graphene film is stacked, and this process is repeated back and forth until the target height is reached to obtain a graphene film block; the graphene film block is sliced ​​along the direction of the graphene film stacking by laser cutting to obtain a graphene gasket with a thickness of 0.3 mm.

[0079] The graphene gasket has a horizontal direction perpendicular to the thickness direction. The graphene gasket includes a plurality of graphene sheets stacked in sequence along the horizontal direction, and a gap is provided between any two adjacent graphene sheets.

[0080] S2. Set silicone adhesive

[0081] The prepared graphene gasket is placed under the spraying equipment, and a silicone adhesive with a viscosity of ≤100mpa*S is sprayed on one surface of the graphene gasket using the spraying equipment, with the side provided with the silicone adhesive facing upward, and the gasket is left to stand for 60 minutes, and the silicone adhesive on the surface of the graphene gasket is wiped off with oil-absorbing paper.

[0082] S3, Pressing

[0083] Prepare an aluminum sheet with a thickness of 10 μm, place the graphene gasket and the aluminum sheet on a clean workbench respectively, and then use a high-precision positioning device to overlap the graphene gasket and the aluminum sheet so that the side of the graphene gasket where the silicone adhesive is set is in contact with the aluminum sheet, and then align them so that they are completely aligned in the length and width directions. Finally, use a pressing device to apply a certain amount of pressure between the graphene gasket and the aluminum sheet to make them tightly combined to obtain a composite thermal conductive gasket.

[0084] Example 2

[0085] The present invention provides a composite thermally conductive pad and a method for preparing the same, which comprises the following steps:

[0086] S1. Prepare graphene gasket

[0087] A dot-shaped acrylic resin adhesive is sprayed on the first layer of graphene film, and then the second layer of graphene film is aligned and placed on the first layer of graphene film, and a layer of acrylic resin adhesive is further coated on the second layer of graphene film, and then the third layer of graphene film is stacked, and this process is repeated back and forth until the target height is reached to obtain a graphene film block; the graphene film block is sliced ​​along the direction of the graphene film stacking by laser cutting to obtain a graphene gasket with a thickness of 0.5 mm.

[0088] The graphene gasket has a horizontal direction perpendicular to the thickness direction. The graphene gasket includes a plurality of graphene sheets stacked in sequence along the horizontal direction, and a gap is provided between any two adjacent graphene sheets.

[0089] S2. Set silicone adhesive

[0090] The prepared graphene gasket is placed under the spraying equipment, and a silicone adhesive with a viscosity of ≤100mpa*S is sprayed on one surface of the graphene gasket using the spraying equipment, with the side provided with the silicone adhesive facing upward, and the gasket is left to stand for 60 minutes, and the silicone adhesive on the surface of the graphene gasket is wiped off with oil-absorbing paper.

[0091] S3, Pressing

[0092] Prepare an aluminum sheet with a thickness of 25 μm, place the graphene gasket and the aluminum sheet on a clean workbench respectively, and then use a high-precision positioning device to overlap the graphene gasket and the aluminum sheet so that the side of the graphene gasket where the silicone adhesive is set is in contact with the aluminum sheet, and then align them so that they are completely aligned in the length and width directions. Finally, use a pressing device to apply a certain amount of pressure between the graphene gasket and the aluminum sheet to make them tightly combined to obtain a composite thermal conductive gasket.

[0093] Example 3

[0094] The present invention provides a composite thermally conductive pad and a method for preparing the same, which comprises the following steps:

[0095] S1. Prepare graphene gasket

[0096] A dot-shaped acrylic resin adhesive is sprayed on the first layer of graphene film, and then the second layer of graphene film is aligned and placed on the first layer of graphene film, and a layer of acrylic resin adhesive is further coated on the second layer of graphene film, and then the third layer of graphene film is stacked, and this process is repeated back and forth until the target height is reached to obtain a graphene film block; the graphene film block is sliced ​​along the direction of the graphene film stacking by laser cutting to obtain a graphene gasket with a thickness of 1 mm.

[0097] The graphene gasket has a horizontal direction perpendicular to the thickness direction. The graphene gasket includes a plurality of graphene sheets stacked in sequence along the horizontal direction, and a gap is provided between any two adjacent graphene sheets.

[0098] S2. Set silicone adhesive

[0099] The prepared graphene gasket is placed under the spraying equipment, and a silicone adhesive with a viscosity of ≤100mpa*S is sprayed on one surface of the graphene gasket using the spraying equipment, with the side provided with the silicone adhesive facing upward, and the gasket is left to stand for 60 minutes, and the silicone adhesive on the surface of the graphene gasket is wiped off with oil-absorbing paper.

[0100] S3, Pressing

[0101] Prepare an aluminum sheet with a thickness of 100 μm, place the graphene gasket and the aluminum sheet on a clean workbench respectively, and then use a high-precision positioning device to overlap the graphene gasket and the aluminum sheet so that the side of the graphene gasket where the silicone adhesive is set is in contact with the aluminum sheet, and then align them so that they are completely aligned in the length and width directions. Finally, use a pressing device to apply a certain amount of pressure between the graphene gasket and the aluminum sheet to make them tightly combined to obtain a composite thermal conductive gasket.

[0102] Example 4

[0103] The embodiment of the present application provides a composite thermally conductive gasket and a preparation method thereof, which is different from Embodiment 2 except that the thickness of the aluminum sheet is changed to 1 μm, while other aspects remain unchanged.

[0104] Example 5

[0105] The embodiment of the present application provides a composite thermally conductive gasket and a preparation method thereof, which is different from Embodiment 2 except that the thickness of the aluminum sheet is changed to 5 μm, and the other aspects remain unchanged.

[0106] Example 6

[0107] The embodiment of the present application provides a composite thermally conductive gasket and a preparation method thereof, which is different from Embodiment 2 except that the thickness of the aluminum sheet is changed to 50 μm, while other aspects remain unchanged.

[0108] Example 7

[0109] The embodiment of the present application provides a composite thermally conductive gasket and a preparation method thereof, which is different from Embodiment 2 except that the thickness of the aluminum sheet is changed to 1000 μm, and the other parts remain unchanged.

[0110] Example 8

[0111] The embodiment of the present application provides a composite thermally conductive gasket and a preparation method thereof, which is different from Embodiment 2 except that the thickness of the graphene gasket is changed to 0.1 μm, and the other aspects remain unchanged.

[0112] Example 9

[0113] The embodiment of the present application provides a composite thermally conductive gasket and a preparation method thereof, which is different from Embodiment 2 except that the thickness of the graphene gasket is changed to 5 μm, while other aspects remain unchanged.

[0114] Example 10

[0115] The embodiment of the present application provides a composite thermally conductive gasket and a preparation method thereof, which is different from Embodiment 2 only by changing the aluminum sheet to an indium sheet, while other aspects remain unchanged.

[0116] Comparative Example 1

[0117] The comparative example of the present application provides a thermally conductive pad and a preparation method thereof, which comprises the following steps:

[0118] A dot-shaped acrylic resin adhesive is sprayed on the first layer of graphene film, and then the second layer of graphene film is aligned and placed on the first layer of graphene film, and a layer of acrylic resin adhesive is further coated on the second layer of graphene film, and then the third layer of graphene film is stacked, and this process is repeated back and forth until the target height is reached to obtain a graphene film block; the graphene film block is sliced ​​along the direction of the graphene film stacking by laser cutting to obtain a graphene gasket with a thickness of 0.5 mm.

[0119] Comparative Example 2

[0120] The comparative example of the present application provides a composite thermally conductive pad and a preparation method thereof, which comprises the following steps:

[0121] S1. Prepare graphene gasket

[0122] A dot-shaped acrylic resin adhesive is sprayed on the first layer of graphene film, and then the second layer of graphene film is aligned and placed on the first layer of graphene film, and a layer of acrylic resin adhesive is further coated on the second layer of graphene film, and then the third layer of graphene film is stacked, and this process is repeated back and forth until the target height is reached to obtain a graphene film block; the graphene film block is sliced ​​along the direction of the graphene film stacking by laser cutting to obtain a graphene gasket with a thickness of 0.5 mm.

[0123] The graphene gasket has a horizontal direction perpendicular to the thickness direction. The graphene gasket includes a plurality of graphene sheets stacked in sequence along the horizontal direction, and a gap is provided between any two adjacent graphene sheets.

[0124] S2. Set silicone adhesive

[0125] The prepared graphene gasket is placed under the spraying equipment, and an organic silicone adhesive with a viscosity of ≤100mpa*S is sprayed on one surface of the graphene gasket using the spraying equipment.

[0126] S3, Pressing

[0127] Prepare an aluminum sheet with a thickness of 25 μm, place the graphene gasket and the aluminum sheet on a clean workbench respectively, and then use a high-precision positioning device to overlap the graphene gasket and the aluminum sheet so that the side of the graphene gasket where the silicone adhesive is set is in contact with the aluminum sheet, and then align them so that they are completely aligned in the length and width directions. Finally, use a pressing device to apply a certain amount of pressure between the graphene gasket and the aluminum sheet to make them tightly combined to obtain a composite thermal conductive gasket.

[0128] Comparative Example 3

[0129] The comparative example of the present application provides a composite thermally conductive gasket and a preparation method thereof, which is different from Example 2 in that only the thickness of the aluminum sheet is changed to 2000 μm, while other parts remain unchanged.

[0130] The parameters of the composite thermally conductive pads of Examples 1 to 10, Comparative Examples 2 to 3, and the thermally conductive pad of Comparative Example 1 are shown in Table 1:

[0131] Table 1 Parameters of the composite thermally conductive pads of Examples 1 to 10, Comparative Examples 2 to 3, and the thermally conductive pad of Comparative Example 1

[0132]

[0133]

[0134] Test Example 1

[0135] The composite thermally conductive gaskets prepared in Examples 1 to 10, Comparative Examples 2 to 3, and the thermally conductive gasket prepared in Comparative Example 1 were taken to measure the bare material thermal resistance, overall thermal resistance, and the number of repeated uses of the graphene gasket in chip testing. The results are shown in Table 2.

[0136] The test method is as follows:

[0137] 1. Thermal resistance test

[0138] The bare graphene gasket or the gasket after composite metal was cut into 25.4*25.4mm and tested using the LONGWIN-9389 equipment from Taiwan, China, with the test pressure set to 40psi.

[0139] 2. Repeated use test

[0140] The graphene thermal pad with a composite metal sheet on the surface was cut into 25.4*25.4mm specifications and compressed using an INSTRON 68 million tensile machine. The compression pressure was set to 60psi and maintained for 30 minutes. The pressure head was then raised and the compression was repeated for 10 times. The sample was taken out to check for damage and placed on a Taiwan Ruiling LONGWIN-9389 device for thermal resistance testing. When the thermal resistance exceeded 15% of the initial thermal resistance or cracks appeared on the surface, this time was recorded as the number of uses.

[0141] Table 2 Performance of the composite thermally conductive pads of Examples 1 to 10, Comparative Examples 2 to 3, and the thermally conductive pad of Comparative Example 1

[0142]

[0143]

[0144] It can be seen from Examples 1 to 9 that when the metal sheet is made of aluminum sheet, the thickness of the metal sheet is 1 μm to 1000 μm, the thickness of the graphene gasket is 0.1 mm to 5 mm, and the thickness of the adhesive layer is ≤ 5 μm, the overall thermal resistance of the composite thermally conductive gasket is 0.076 °C cm 2 / W~3.4℃cm 2 / W, the number of times it is reused in chip testing is 70 to 1560 times;

[0145] It can be seen from Example 10 that when the metal sheet is made of indium sheet, the thickness of the metal sheet is 25 μm, the thickness of the graphene gasket is 0.5 mm, and the thickness of the adhesive layer is ≤ 5 μm, the overall thermal resistance of the composite thermally conductive gasket is 0.131 °C cm 2 / W, the number of times it is reused in chip testing is 530 times;

[0146] From the comparison between comparative example 1 and embodiment 2, it can be seen that comparative example 1 has only graphene gasket and no aluminum sheet, and the overall thermal resistance of the thermal conductive gasket is 0.068℃cm 2 / W, the number of times it was reused in chip testing was only 30 times, which was far less than the number of times the composite thermal conductive pad of Example 2 composited with aluminum sheet was reused in chip testing;

[0147] From the comparison between Comparative Example 2 and Example 2, it can be seen that the thickness of the adhesive layer of Comparative Example 2 is 10 μm to 20 μm, and the overall thermal resistance of the composite thermally conductive gasket obtained is 0.174°C cm 2 / W, which is higher than the overall thermal resistance of the composite thermally conductive pad of Example 2;

[0148] From the comparison between comparative example 3 and embodiment 2, it can be seen that the thickness of the metal sheet in comparative example 3 is 2000 μm, and the overall thermal resistance of the composite thermal conductive pad obtained is as high as 5.6°C cm 2 / W, which is much higher than the overall thermal resistance of the composite thermally conductive gasket in Example 2.

[0149] The above description is only a specific embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for preparing a composite thermally conductive gasket, characterized in that: The preparation method of the thermal conductive gasket comprises: preparing a graphene gasket, disposing a first adhesive on one side of the graphene gasket, and making the side provided with the first adhesive face upward, standing for at least 30 minutes, removing the first adhesive on the surface of the graphene gasket, and pressing a metal sheet on the side of the graphene gasket provided with the first adhesive; The graphene gasket has a horizontal direction perpendicular to the thickness direction, and the graphene gasket includes a plurality of graphene sheets stacked in sequence along the horizontal direction, and there is a gap between any two adjacent graphene sheets; The thickness of the metal sheet is 1 μm to 1000 μm.

2. The method for preparing the composite thermally conductive pad according to claim 1, characterized in that: The thickness of the metal sheet is 5 μm to 50 μm.

3. The method for preparing the composite thermally conductive pad according to claim 1, characterized in that: The metal sheet includes an aluminum sheet, a copper sheet, a nickel sheet or an indium sheet; Optionally, the metal sheet is an aluminum sheet.

4. The method for preparing the composite thermally conductive gasket according to claim 1, characterized in that: The viscosity of the first adhesive is ≤100 mpa*S.

5. The method for preparing the composite thermally conductive pad according to claim 4, characterized in that: The first adhesive is organic silicone adhesive.

6. The method for preparing the composite thermally conductive pad according to claim 1, characterized in that: The method for removing the first adhesive on the surface of the graphene gasket includes wiping it with oil-absorbing paper.

7. The method for preparing the composite thermally conductive pad according to claim 1, characterized in that: The method of pressing the metal sheet and the graphene gasket comprises: The metal sheet and the graphene gasket are pressed together using a pressing device, the pressing temperature is 50° C. to 150° C., the pressing pressure is 1 MPa to 100 MPa, and the pressing time is 5 min to 20 min.

8. The method for preparing the composite thermally conductive gasket according to claim 1, characterized in that: The thickness of the graphene gasket is 0.1 mm to 5 mm; Optionally, the graphene gasket has a thickness of 0.1 mm to 1 mm.

9. The method for preparing the composite thermally conductive gasket according to claim 1, characterized in that: Two adjacent graphene sheets are bonded by using a second adhesive, and the second adhesive is distributed in an island shape.

10. A composite thermally conductive gasket, characterized in that: The composite thermally conductive gasket is prepared according to the preparation method of the composite thermally conductive gasket according to any one of claims 1 to 9.

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