Composite heat-conducting gasket
By using a composite structure of graphene pads and metal sheets, the interfacial thermal resistance is reduced, and the thermal conductivity and strength are improved. This solves the problem of graphene thermal pads being easily damaged during repeated use, and achieves a higher number of reuses and better thermal conductivity.
Patent Information
- Application Number
- CN202520285398.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-20
- Publication Date
- 2026-02-03
- Estimated Expiration
- 2035-02-20
AI Technical Summary
Existing graphene thermal pads have poor strength and are easily damaged during repeated use, resulting in a significant loss of thermal conductivity and failing to meet the repeated use requirements for chip testing.
A composite structure of graphene pads and metal sheets is adopted. Graphene pads, adhesive layers and metal sheets are stacked sequentially in the thickness direction. The thickness of the metal sheets is 1μm~1000μm and the thickness of the adhesive layer is ≤5μm. The adhesive blocks are connected in an island-like distribution to reduce interfacial thermal resistance and improve thermal conductivity and strength.
This improved the thermal conductivity and mechanical strength of the composite thermal pad, extended the number of reusable uses, reduced the cost of chip testing, and solved the problem of graphene pad breakage during repeated use.
Smart Images
Figure CN223872637U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of thermal conductivity technology, and more specifically, to a composite thermally conductive pad. Background Technology
[0002] Graphene is a single-layer, two-dimensional honeycomb lattice structure material composed of carbon atoms with sp² hybrid orbitals. Due to its unique physical and chemical properties, graphene has attracted widespread attention in the field of materials science. Among its applications, graphene thermal pads, utilizing graphene's high thermal conductivity, are widely used in the thermal management of electronic devices. Currently, graphene thermal pads are used in chip testing. However, during repeated use, their inherent low strength makes them prone to breakage during testing. Therefore, improving the strength of graphene thermal pads is crucial for enhancing their reusability. Utility Model Content
[0003] The purpose of this application is to provide a composite thermally conductive pad that has both high strength and good thermal conductivity.
[0004] In a first aspect, embodiments of this application provide a composite thermally conductive pad, which includes a graphene pad, an adhesive layer, and a metal sheet arranged sequentially along the thickness direction. The graphene pad has a horizontal direction perpendicular to the thickness direction. The graphene pad includes a plurality of graphene sheets arranged sequentially along the horizontal direction. The thickness of the adhesive layer is ≤5μm, and the thickness of the metal sheet is 1μm~1000μm.
[0005] In the above implementation process, the composite thermal pad of this application is composed of a graphene pad and a metal sheet. The thickness of the metal sheet is only 1μm to 1000μm, which can significantly reduce the interfacial thermal resistance between the graphene thermal pad and the aluminum sheet, reduce the thermal performance loss of the graphene thermal pad, and improve the thermal conductivity of the composite thermal pad. The graphene pad includes multiple graphene sheets arranged sequentially in a horizontal direction, which have good thermal conductivity. The connecting layer between the graphene pad and the metal sheet is thin and has little impact on the thermal conductivity of the entire composite thermal pad. This allows the composite thermal pad to have both high strength and good thermal conductivity, increasing its reusability in chip testing.
[0006] In one possible implementation, the thickness of the metal sheet is 5 μm to 50 μm.
[0007] In the above implementation process, by keeping the thickness of the metal sheet within the above range, it is beneficial to further reduce the interfacial thermal resistance between the graphene thermal pad and the aluminum sheet, reduce the thermal performance loss of the graphene thermal pad, and improve the thermal conductivity of the composite thermal pad.
[0008] In one possible implementation, the metal sheet is an aluminum sheet, a copper sheet, a nickel sheet, or an indium sheet.
[0009] In one possible implementation, the metal sheet is an aluminum sheet.
[0010] In the above implementation process, choosing aluminum sheet as the metal sheet can further improve the strength of the composite thermal pad, thereby increasing its reusability in chip testing.
[0011] In one possible implementation, the adhesive layer comprises a plurality of first adhesive blocks arranged in an island-like pattern.
[0012] In the above implementation process, multiple first adhesive blocks distributed in an island shape are used to connect the graphene pad and the metal sheet. This allows many areas of the graphene pad near the end face of the metal sheet that do not have first adhesive blocks to directly contact the metal sheet. As a result, the composite thermal pad has both high strength and good thermal conductivity, increasing its reusability in chip testing.
[0013] In one possible implementation, two adjacent graphene sheets are bonded together by a plurality of second adhesive blocks, which are distributed in an island-like pattern.
[0014] In the above process, the second adhesive block, which is distributed in an island-like manner, can not only bond multiple graphene sheets together, but also does not have a significant impact on the overall thermal conductivity of the graphene pad.
[0015] In one possible implementation, the graphene sheet includes a large surface near an adjacent graphene sheet, one end of a first adhesive block is connected to a metal sheet, and the other end is connected to the large surface of the graphene sheet and / or a second adhesive block.
[0016] In the above implementation process, the two ends of the first adhesive block are used to connect the large surfaces of the metal sheet and the graphene sheet and / or the second adhesive block, respectively, so that the end faces of the graphene sheets of the graphene pad close to the metal sheet can directly contact the metal sheet, thereby making the resulting composite thermal pad have both high strength and good thermal conductivity, and increasing its reusability in chip testing.
[0017] In one possible implementation, the first adhesive block comprises an organosilicon adhesive.
[0018] In one possible implementation, the thickness of the graphene pad is 0.1 mm to 5 mm.
[0019] In one possible implementation, the thickness of the graphene sheet is 100 nm to 500 nm. Attached Figure Description
[0020] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.
[0021] Figure 1 This is a schematic diagram of the structure of the composite thermal pad according to an embodiment of this application;
[0022] Figure 2 for Figure 1 Enlarged view of region A;
[0023] Figure 3 for Figure 1 A magnified view of region B.
[0024] Icons: 10-Composite thermal conductive pad; 100-Graphene pad; 110-Graphene sheet; 120-Second adhesive block; 200-Adhesive layer; 210-First adhesive block; 300-Metal sheet. Detailed Implementation
[0025] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.
[0026] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.
[0027] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.
[0028] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this application is in use. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. In addition, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.
[0029] Furthermore, terms such as "horizontal," "vertical," and "sag" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.
[0030] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set up," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.
[0031] Metallic materials are also commonly used thermally conductive materials, possessing excellent thermal conductivity and processability. This application proposes that combining metallic materials with graphene pads to form composite thermally conductive pads could potentially improve the mechanical strength of graphene pads and increase their reusability in chip testing.
[0032] However, due to the different materials of the metal material and the presence of a composite interface, there is a large interfacial thermal resistance between the metal material and the graphene pad, resulting in a significant loss of thermal performance of the graphene pad and poor thermal conductivity of the composite thermal pad.
[0033] Based on this, please refer to Figure 1 This application provides a composite thermally conductive pad 10, which includes a graphene pad 100, an adhesive layer 200 and a metal sheet 300 arranged sequentially along the thickness direction.
[0034] Please refer to Figure 2The graphene pad 100 is a thermally conductive pad made from a raw material including graphene. It has a horizontal direction perpendicular to the thickness direction. The graphene pad 100 includes a plurality of graphene sheets 110 arranged sequentially in the horizontal direction, and there is a gap between any two adjacent graphene sheets 110.
[0035] The thickness of the graphene gasket 100 is 0.1mm~5mm.
[0036] As an example, the thickness of the graphene pad 100 can be 0.1mm, 0.2mm, 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm or 5mm.
[0037] Optionally, the thickness of the graphene sheet 110 is 100nm~500nm.
[0038] Optionally, two adjacent graphene sheets 110 are bonded together by a plurality of second adhesive blocks 120, and the plurality of second adhesive blocks 120 are distributed in an island-like manner.
[0039] The second adhesive block, which is distributed in an island-like pattern, can not only bond multiple graphene sheets 110 together, but also does not significantly affect the overall thermal conductivity of the graphene pad 100.
[0040] This application provides a method for preparing a graphene pad 100, comprising the following steps:
[0041] A dotted acrylic resin adhesive is sprayed onto the first graphene film. Then, the second graphene film is aligned and placed on the first graphene film. Another layer of acrylic resin adhesive is then applied to the second graphene film. The third graphene film is then stacked on top of this, and this process is repeated until the target height is reached to obtain a graphene film block. The graphene film block is then sliced along the stacking direction of the graphene films using laser cutting to obtain a graphene pad 100.
[0042] Please see Figure 1 and 3 The adhesive layer 200 is a layered structure that connects the graphene pad 100 and the metal sheet 300, and its thickness is ≤5μm.
[0043] As an example, the thickness of the adhesive layer 200 can be 0.5μm, 1μm, 2μm, 3μm, 4μm or 5μm.
[0044] Optionally, the adhesive layer 200 includes a plurality of first adhesive blocks 210 distributed in an island-like manner. The plurality of first adhesive blocks 210 distributed in an island-like manner are used to connect the graphene pad 100 and the metal sheet 300. This allows many areas of the graphene sheets 110 of the graphene pad 100 near the end face of the metal sheet 300 that do not have first adhesive blocks 210 to directly contact the metal sheet 300. As a result, the composite thermal pad 10 has both high strength and good thermal conductivity, and improves its reusability in chip testing.
[0045] Optionally, the first adhesive block 210 includes an organosilicon adhesive.
[0046] Metal sheet 300 is a sheet-like structure made of metal material with a thickness of 1μm to 1000μm.
[0047] As an example, the thickness of the metal sheet 300 can be 1μm, 2μm, 5μm, 10μm, 50μm, 100μm, 200μm, 300μm, 400μm, 500μm, 600μm, 700μm, 800μm, 900μm or 1000μm.
[0048] Optionally, the thickness of the metal sheet 300 is 5μm to 50μm.
[0049] By ensuring that the thickness of the metal sheet 300 is within the aforementioned range, it is beneficial to further reduce the interfacial thermal resistance between the graphene thermal pad and the aluminum sheet, reduce the thermal performance loss of the graphene thermal pad, and improve the thermal conductivity of the composite thermal pad 10.
[0050] Metal sheet 300 includes aluminum sheet, copper sheet, nickel sheet or indium sheet.
[0051] Optionally, the metal sheet 300 is an aluminum sheet.
[0052] Choosing aluminum sheet as the metal sheet 300 can further improve the strength of the composite thermal pad 10, thereby increasing its reusability in chip testing.
[0053] Please see Figure 3 The graphene sheet 110 includes a large surface close to the adjacent graphene sheet 110. One end of the first adhesive 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 adhesive block 120.
[0054] The two ends of the first adhesive block 210 are used to connect the large surfaces of the metal sheet 300 and the graphene sheet 110 and / or the second adhesive block 120, respectively, so that the multiple graphene sheets 110 of the graphene pad 100 can directly contact the end face of the metal sheet 300 near the metal sheet 300, thereby making the composite thermal pad 10 have both high strength and good thermal conductivity, and increasing its reusability in chip testing.
[0055] The composite thermal pad of this application is composed of a graphene pad and a metal sheet. The thickness of the metal sheet is only 1μm to 1000μm, which can significantly reduce the interfacial thermal resistance between the graphene thermal pad and the aluminum sheet, reduce the thermal performance loss of the graphene thermal pad, and improve the thermal conductivity of the composite thermal pad. The graphene pad includes multiple graphene sheets arranged sequentially in a horizontal direction, which have good thermal conductivity. The connecting layer between the graphene pad and the metal sheet is thin and has little impact on the thermal conductivity of the entire composite thermal pad. This allows the composite thermal pad to have both high strength and good thermal conductivity, increasing its reusability in chip testing, reducing the testing cost of chips or power devices, and improving the problem of graphene pad residue at the chip testing end.
[0056] The composite thermally conductive pad of this application has wide applications in fields such as heat dissipation management of electronic devices, material recycling, and the research and development of high-performance thermally conductive materials. Firstly, in the field of heat dissipation management of electronic devices, the composite thermally conductive pad of this application can significantly improve reusability testing performance, reduce interfacial thermal resistance, and enhance thermal conductivity. This is of great significance for solving the common heat dissipation problems in current electronic devices. Furthermore, as electronic devices develop towards high performance, miniaturization, and integration, heat dissipation problems are becoming increasingly prominent, making the application prospects of this technical solution broad. Secondly, in the field of material recycling, the composite thermally conductive pad of this application features a detachable design, enabling the reuse of graphene pads, reducing resource waste, and lowering production costs. This is of great significance for promoting the development of material recycling technology and achieving sustainable development. With increasing environmental awareness and the growing severity of resource shortages, the demand for material recycling technology is increasing, making the application prospects of this technical solution broad. Finally, in the field of high-performance thermal conductive material research and development, the composite thermal conductive pad of this application can fully utilize the thermal conductivity of graphene and improve thermal conductivity efficiency. This is of great significance for developing higher-performance thermal conductive materials and meeting the heat dissipation requirements of high-end electronic devices. With the development of high-end electronic devices, the demand for high-performance thermal conductive materials is increasing, and the application prospects of this technical solution are broad. In summary, the composite thermal conductive pad of this application has broad application prospects and large market demand, and is expected to play an important role in fields such as heat dissipation management of electronic devices, material reuse, and the research and development of high-performance thermal conductive materials.
[0057] The composite thermally conductive pad of this application can be obtained by the following methods:
[0058] S1. Prepare graphene pads
[0059] The graphene pad has a horizontal direction perpendicular to the thickness direction. The graphene pad includes multiple graphene sheets arranged sequentially in the horizontal direction, and there is a gap between any two adjacent graphene sheets.
[0060] S2, Apply the first adhesive.
[0061] Place the graphene pad under the spraying equipment, spray the first adhesive onto one surface of the graphene pad with the side with the first adhesive facing upwards, let it stand for at least 30 minutes, and then remove the first adhesive from the surface of the graphene pad.
[0062] Optionally, the viscosity of the first adhesive is ≤100mpa*S. The first adhesive with a viscosity ≤100mpa*S has good permeability, which is beneficial for the first adhesive to penetrate into the gaps between the graphene sheets during the standing process.
[0063] Alternatively, methods for removing the first adhesive from the surface of the graphene pad include wiping it off with blotting paper.
[0064] S3, Pressing
[0065] Prepare a metal sheet. Place the graphene pad and the metal sheet on a clean workbench. Then, using a high-precision positioning device, overlap the graphene pad and the metal sheet so that the side of the graphene pad that was coated with the first adhesive contacts the metal sheet. Next, align them so that they are completely aligned in the length and width directions. Finally, use a pressing device to apply a certain pressure between the graphene pad and the metal sheet to make them tightly bonded, thus obtaining a composite thermal conductive pad.
[0066] Optionally, the pressing temperature is 50℃~150℃, the pressing pressure is 1MPa~100MPa, and the pressing time is 5min~20min.
[0067] As an example, the pressing temperature can be 50℃, 60℃, 70℃, 80℃, 90℃, 100℃, 110℃, 120℃, 130℃, 140℃ or 150℃, 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.
[0068] The following describes a composite thermally conductive pad of this application in further detail with reference to embodiments.
[0069] Example 1
[0070] This application provides a composite thermally conductive pad and its preparation method, which includes the following steps:
[0071] S1. Prepare graphene pads
[0072] A dotted acrylic resin adhesive is sprayed onto the first graphene film. Then, the second graphene film is aligned and placed on the first graphene film. Another layer of acrylic resin adhesive is then applied to the second graphene film. The third graphene film is then stacked on top of this, and this process is repeated until the target height is reached to obtain a graphene film block. The graphene film block is then sliced along the stacking direction of the graphene films using laser cutting to obtain graphene pads with a thickness of 0.3 mm.
[0073] The graphene pad has a horizontal direction perpendicular to the thickness direction. The graphene pad includes multiple graphene sheets arranged sequentially in the horizontal direction, and there is a gap between any two adjacent graphene sheets.
[0074] S2, Set the silicone adhesive
[0075] The prepared graphene gasket was placed under the spraying equipment. The spraying equipment was used to spray an organosilicon adhesive with a viscosity ≤100mpa*S onto one surface of the graphene gasket, with the side with the organosilicon adhesive facing upwards. After standing for 60 minutes, the organosilicon adhesive on the surface of the graphene gasket was wiped off with oil-absorbing paper.
[0076] S3, Pressing
[0077] Prepare an aluminum sheet with a thickness of 10μm. Place the graphene pad and the aluminum sheet on a clean workbench. Then, using a high-precision positioning device, overlap the graphene pad and the aluminum sheet so that the side of the graphene pad with the silicone adhesive is in contact with the aluminum sheet. Next, align them so that they are completely aligned in the length and width directions. Finally, use a pressing device to apply a certain pressure between the graphene pad and the aluminum sheet to make them tightly bonded, thus obtaining a composite thermal conductive pad.
[0078] Example 2
[0079] This application provides a composite thermally conductive pad and its preparation method, which includes the following steps:
[0080] S1. Prepare graphene pads
[0081] A dotted acrylic resin adhesive is sprayed onto the first graphene film. Then, the second graphene film is aligned and placed on the first graphene film. Another layer of acrylic resin adhesive is then applied to the second graphene film. The third graphene film is then stacked on top of this, and this process is repeated until the target height is reached to obtain a graphene film block. The graphene film block is then sliced along the stacking direction of the graphene films using laser cutting to obtain graphene pads with a thickness of 0.5 mm.
[0082] The graphene pad has a horizontal direction perpendicular to the thickness direction. The graphene pad includes multiple graphene sheets arranged sequentially in the horizontal direction, and there is a gap between any two adjacent graphene sheets.
[0083] S2, Set the silicone adhesive
[0084] The prepared graphene gasket was placed under the spraying equipment. The spraying equipment was used to spray an organosilicon adhesive with a viscosity ≤100mpa*S onto one surface of the graphene gasket, with the side with the organosilicon adhesive facing upwards. After standing for 60 minutes, the organosilicon adhesive on the surface of the graphene gasket was wiped off with oil-absorbing paper.
[0085] S3, Pressing
[0086] Prepare an aluminum sheet with a thickness of 25μm. Place the graphene pad and the aluminum sheet on a clean workbench. Then, using a high-precision positioning device, overlap the graphene pad and the aluminum sheet so that the side of the graphene pad with the silicone adhesive is in contact with the aluminum sheet. Next, align them so that they are completely aligned in the length and width directions. Finally, use a pressing device to apply a certain pressure between the graphene pad and the aluminum sheet to make them tightly bonded, thus obtaining a composite thermal conductive pad.
[0087] Example 3
[0088] This application provides a composite thermally conductive pad and its preparation method, which includes the following steps:
[0089] S1. Prepare graphene pads
[0090] A dotted acrylic resin adhesive is sprayed onto the first graphene film. Then, the second graphene film is aligned and placed on the first graphene film. Another layer of acrylic resin adhesive is then applied to the second graphene film. The third graphene film is then stacked on top of this, and this process is repeated until the target height is reached to obtain a graphene film block. The graphene film block is then sliced along the direction of the graphene film stacking using laser cutting to obtain a graphene pad with a thickness of 1 mm.
[0091] The graphene pad has a horizontal direction perpendicular to the thickness direction. The graphene pad includes multiple graphene sheets arranged sequentially in the horizontal direction, and there is a gap between any two adjacent graphene sheets.
[0092] S2, Set the silicone adhesive
[0093] The prepared graphene gasket was placed under the spraying equipment. The spraying equipment was used to spray an organosilicon adhesive with a viscosity ≤100mpa*S onto one surface of the graphene gasket, with the side with the organosilicon adhesive facing upwards. After standing for 60 minutes, the organosilicon adhesive on the surface of the graphene gasket was wiped off with oil-absorbing paper.
[0094] S3, Pressing
[0095] Prepare an aluminum sheet with a thickness of 100μm. Place the graphene pad and the aluminum sheet on a clean workbench. Then, using a high-precision positioning device, overlap the graphene pad and the aluminum sheet so that the side of the graphene pad with the silicone adhesive is in contact with the aluminum sheet. Next, align them so that they are completely aligned in the length and width directions. Finally, use a pressing device to apply a certain pressure between the graphene pad and the aluminum sheet to make them tightly bonded, thus obtaining a composite thermal conductive pad.
[0096] Example 4
[0097] This application provides a composite thermally conductive pad and its preparation method, which is based on Example 2, except that the thickness of the aluminum sheet is changed to 1 μm, while other aspects remain unchanged.
[0098] Example 5
[0099] This application provides a composite thermal conductive pad and its preparation method, which is based on Example 2, except that the thickness of the aluminum sheet is changed to 5 μm, while other aspects remain unchanged.
[0100] Example 6
[0101] This application provides a composite thermal conductive pad and its preparation method, which is based on Example 2, except that the thickness of the aluminum sheet is changed to 50 μm, while other aspects remain unchanged.
[0102] Example 7
[0103] This application provides a composite thermally conductive pad and its preparation method, which is based on Example 2, except that the thickness of the aluminum sheet is changed to 1000 μm, while other aspects remain unchanged.
[0104] Example 8
[0105] This application provides a composite thermally conductive pad and its preparation method, which is based on Example 2, except that the thickness of the graphene pad is changed to 0.1 μm, while other aspects remain unchanged.
[0106] Example 9
[0107] This application provides a composite thermally conductive pad and its preparation method, which is based on Example 2, except that the thickness of the graphene pad is changed to 5 μm, while other aspects remain unchanged.
[0108] Example 10
[0109] This application provides a composite thermal pad and its preparation method, which is based on Example 2, except that the aluminum sheet is replaced with an indium sheet, while the others remain unchanged.
[0110] Comparative Example 1
[0111] This application provides a comparative example of a thermally conductive pad and its preparation method, which includes the following steps:
[0112] A dotted acrylic resin adhesive is sprayed onto the first graphene film. Then, the second graphene film is aligned and placed on the first graphene film. Another layer of acrylic resin adhesive is then applied to the second graphene film. The third graphene film is then stacked on top of this, and this process is repeated until the target height is reached to obtain a graphene film block. The graphene film block is then sliced along the stacking direction of the graphene films using laser cutting to obtain graphene pads with a thickness of 0.5 mm.
[0113] Comparative Example 2
[0114] This application provides a comparative example of a composite thermally conductive pad and its preparation method, which includes the following steps:
[0115] S1. Prepare graphene pads
[0116] A dotted acrylic resin adhesive is sprayed onto the first graphene film. Then, the second graphene film is aligned and placed on the first graphene film. Another layer of acrylic resin adhesive is then applied to the second graphene film. The third graphene film is then stacked on top of this, and this process is repeated until the target height is reached to obtain a graphene film block. The graphene film block is then sliced along the stacking direction of the graphene films using laser cutting to obtain graphene pads with a thickness of 0.5 mm.
[0117] The graphene pad has a horizontal direction perpendicular to the thickness direction. The graphene pad includes multiple graphene sheets arranged sequentially in the horizontal direction, and there is a gap between any two adjacent graphene sheets.
[0118] S2, Set the silicone adhesive
[0119] The prepared graphene pad is placed under a spraying device, and an organosilicon adhesive with a viscosity ≤100mpa*S is sprayed onto one surface of the graphene pad using the spraying device.
[0120] S3, Pressing
[0121] Prepare an aluminum sheet with a thickness of 25μm. Place the graphene pad and the aluminum sheet on a clean workbench. Then, using a high-precision positioning device, overlap the graphene pad and the aluminum sheet so that the side of the graphene pad with the silicone adhesive is in contact with the aluminum sheet. Next, align them so that they are completely aligned in the length and width directions. Finally, use a pressing device to apply a certain pressure between the graphene pad and the aluminum sheet to make them tightly bonded, thus obtaining a composite thermal conductive pad.
[0122] Comparative Example 3
[0123] This application provides a comparative example of a composite thermally conductive pad and its preparation method, which is based on Example 2, except that the thickness of the aluminum sheet is changed to 2000 μm, while other aspects remain unchanged.
[0124] The parameters of the composite thermal pads of Examples 1-10, Comparative Examples 2-3, and the thermal pad of Comparative Example 1 are shown in Table 1:
[0125] Table 1. Parameters of the composite thermal pads of Examples 1-10, Comparative Examples 2-3, and the thermal pad of Comparative Example 1.
[0126]
[0127] Experimental Example 1
[0128] The composite thermal pads prepared in Examples 1-10 and Comparative Examples 2-3, and the thermal pad prepared in Comparative Example 1 were used to measure the thermal resistance of the graphene pad bare material, the overall thermal resistance, and the number of times it could be reused in chip testing. The results are shown in Table 2.
[0129] The testing method is as follows:
[0130] 1. Thermal resistance test
[0131] The graphene gasket bare material or the composite metal gasket was cut into 25.4*25.4mm pieces and tested using a LONGWIN-9389 device from Taiwan, China, with the test pressure set to 40psi.
[0132] 2. Repeat usage test
[0133] The graphene thermal pad with a surface-composite metal sheet was cut into 25.4*25.4mm sizes and compressed using an INSTRON 68 million tensile tester. The compression pressure was set to 60psi and the holding time was 30 minutes. Then the pressure head was raised and the compression was repeated 10 times. The sample was removed and the damage was checked. It was then placed in a LONGWIN-9389 thermal resistance tester from Taiwan, China for testing. When the thermal resistance exceeded the initial thermal resistance by 15% or cracks appeared on the surface, the number of times it was used was recorded.
[0134] Table 2 Performance of composite thermal pads in Examples 1-10, Comparative Examples 2-3, and Comparative Example 1
[0135]
[0136] As shown in Examples 1-9, when the metal sheet is made of aluminum with a thickness of 1μm to 1000μm, the graphene pad has a thickness of 0.1mm to 5mm, and the adhesive layer thickness is ≤5μm, the overall thermal resistance of the resulting composite thermally conductive pad is 0.076℃cm. 2 / W~3.4℃cm 2 / W, which can be reused 70 to 1560 times in chip testing;
[0137] As shown in Example 10, when the metal sheet is made of indium, has a thickness of 25 μm, the graphene pad has a thickness of 0.5 mm, and the adhesive layer thickness is ≤5 μm, the overall thermal resistance of the resulting composite thermal pad is 0.131 °C / cm². 2 / W, which can be reused 530 times in chip testing;
[0138] A comparison of Comparative Example 1 and Example 2 shows that Comparative Example 1 only has a graphene pad and no aluminum sheet; the overall thermal resistance of the thermally conductive pad is 0.068 °C / cm. 2 / W, the number of times it can be reused in chip testing is only 30 times, which is far less than the number of times the composite thermal pad of Example 2 with aluminum sheet can be reused in chip testing;
[0139] A comparison between Comparative Example 2 and Example 2 shows that the adhesive layer thickness of Comparative Example 2 is 10μm~20μm, and the overall thermal resistance of the resulting composite thermally conductive pad is 0.174℃cm. 2 / W, which is higher than the overall thermal resistance of the composite thermal pad in Example 2;
[0140] A comparison between Comparative Example 3 and Example 2 shows that the metal sheet thickness of Comparative Example 3 is 2000 μm, and the overall thermal resistance of the resulting composite thermal pad is as high as 5.6 °C / cm. 2 / W, which is far higher than the overall thermal resistance of the composite thermal pad in Example 2.
[0141] The above description is merely a specific embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.
Claims
1. A composite thermally conductive pad, characterized in that, The composite thermally conductive pad includes a graphene pad, an adhesive layer, and a metal sheet stacked sequentially along the thickness direction. The graphene pad has a horizontal direction perpendicular to the thickness direction. The graphene pad includes a plurality of graphene sheets stacked sequentially along the horizontal direction. The thickness of the adhesive layer is ≤5μm, and the thickness of the metal sheet is 1μm to 1000μm.
2. The composite thermally conductive pad according to claim 1, characterized in that, The thickness of the metal sheet is 5μm to 50μm.
3. The composite thermally conductive pad according to claim 1, characterized in that, The metal sheet is an aluminum sheet, copper sheet, nickel sheet, or indium sheet.
4. The composite thermally conductive pad according to claim 1, characterized in that, The metal sheet is an aluminum sheet.
5. The composite thermally conductive pad according to claim 1, characterized in that, The adhesive layer includes a plurality of first adhesive blocks distributed in an island-like pattern.
6. The composite thermally conductive pad according to claim 5, characterized in that, Two adjacent graphene sheets are bonded together by a plurality of second adhesive blocks, and the plurality of second adhesive blocks are distributed in an island-like manner.
7. The composite thermally conductive pad according to claim 6, characterized in that, The graphene sheet includes a large surface close to the adjacent graphene sheet, one end of the first adhesive block is connected to the metal sheet, and the other end is connected to the large surface of the graphene sheet and / or the second adhesive block.
8. The composite thermally conductive pad according to claim 5, characterized in that, The first adhesive block comprises an organosilicon adhesive.
9. The composite thermally conductive pad according to claim 1, characterized in that, The thickness of the graphene pad is 0.1 mm to 5 mm.
10. The composite thermally conductive pad according to claim 1, characterized in that, The thickness of the graphene sheet is 100nm to 500nm.