A vertical thermal interface material matrix content control method and apparatus

Abstract

The application discloses a kind of vertical thermal interface material matrix content control method and device, the present application is placed in the surface of several graphene films coated or soaked polymer matrix precursor of stack, then compression, compression to the height required, control arc-shaped substrate flattening, make polymer matrix precursor overflow from middle to edge, control polymer matrix content in vertical thermal interface material is 12%~20% after solidification. By the polymer between graphene film layers, good bonding of graphene film is realized, further cutting obtains graphene vertical thermal interface material with certain strength, surface glue residual amount is less, surface is bright, contact thermal resistance is low, and has good uniformity.

Description

Technical Field

[0001] This invention belongs to the field of thermal interface material preparation, and particularly relates to a method and apparatus for controlling the matrix content of vertical thermal interface materials. Background Technology

[0002] Thermal interface materials are a general term for materials used to reduce the thermal resistance between heat-generating and heat-dissipating devices. As chip performance increases dramatically, the heat generated per unit area also increases dramatically, placing higher demands on thermal interface materials. Poor heat dissipation can severely impact the lifespan and reliability of electronic devices. Traditional thermal interface materials (such as silicone grease and thermal pads) either have low thermal conductivity (typically less than 10 W / mK) or, while having high thermal conductivity, are too rigid (such as metals), failing to effectively fill the tiny gaps between the chip and the heatsink, resulting in poor actual heat dissipation. Therefore, an ideal thermal interface material must possess two seemingly contradictory characteristics: extremely high vertical thermal conductivity and excellent flexibility. Graphene itself has excellent thermal conductivity in the horizontal direction (in-plane), but poor thermal conductivity in the vertical direction (thickness direction).

[0003] To meet the aforementioned characteristics of thermal interface materials, vertical thermal interface materials have been developed based on the inherent properties of graphene. These materials utilize technology to arrange graphene vertically, creating a continuous thermally conductive highway running from the bottom to the top of the material. This allows heat to rapidly pass through these vertically aligned graphene frameworks, increasing the overall vertical thermal conductivity of the material by several orders of magnitude, even surpassing many metals. To achieve this vertical arrangement, graphene films are typically coated or impregnated with polymer matrix precursors (such as silicone rubber or epoxy resin), then stacked, compressed, and cured to obtain a block. Within the block, the graphene films are bonded together by polymers between the layers. The block is then cut along a direction perpendicular to the graphene film stacking direction to obtain a robust, vertically aligned graphene vertical thermal interface material. However, in this scheme, the matrix content has a significant impact on the performance of graphene vertical thermal interface materials: if the matrix content is too low, it is difficult to achieve adhesion of the graphene film through the polymer between the graphene film layers, and the thermal interface material is prone to dispersion, affecting long-term performance; if the matrix content is too high, that is, if the graphene content is too low, the continuous thermal conduction pathways in the thermal interface material are reduced, resulting in poor thermal conductivity of the thermal interface material; at the same time, if the matrix content is too high, when the bulk is cut along the direction perpendicular to the graphene film, the matrix between the layers is easily carried out and covers the surface of the thermal interface material, making it difficult for the graphene to directly contact the heat dissipation device or the heat generation device, greatly increasing the thermal resistance of the thermal interface, resulting in extremely high thermal resistance of the thermal interface material. Therefore, how to control the matrix content in the vertical thermal interface material is crucial for the preparation of high-performance thermal interface materials. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by providing a method and apparatus for controlling the matrix content of vertical thermal interface materials.

[0005] The objective of this invention is achieved through the following technical solution: A method for controlling the matrix content of a vertical thermal interface material involves placing an arc-shaped substrate on the surface of several stacked graphene films coated or soaked with polymer matrix precursors, then compressing it to the required height, and then controlling the arc-shaped substrate to flatten it so that the polymer matrix precursors overflow from the middle to the edge, thereby controlling the polymer matrix content in the cured vertical thermal interface material to be 12%~20%.

[0006] Furthermore, the material of the arc-shaped substrate is stainless steel, pure titanium, Teflon, etc.

[0007] Furthermore, the viscosity of the polymer matrix precursor is 20 to 1500 viscosities, which facilitates membrane impregnation.

[0008] Based on the same principle, this invention also provides a vertical thermal interface material matrix content control device. The device mainly includes an outer frame, a pressure head, a screw, a pair of insert plates, several insert strips, an arc-shaped base plate, and several first flat plates. The outer frame consists of a rectangular frame and upper and lower plates disposed at the upper and lower parts of the rectangular frame. Of the four sides of the rectangular frame, the first side is opposite to the third side, and the second side is opposite to the fourth side. The first and third sides have the same structure, each with a first square through-hole in the middle, the width of which is a first dimension. The second and fourth sides have the same structure, with symmetrical third square through-holes on both the left and right sides along the length direction. The width of the third square through-hole matches the thickness of the insert strips and the first flat plates. During use, several insert strips are fixed by being inserted into the third square through-holes. After insertion, the distance between the inner sides of the left and right inserts is the second dimension; the inner sides of the second and fourth sides are respectively provided with first slots that connect from top to bottom along the length of the first square through hole, and the upper plate is provided with corresponding second square through holes at the opposite positions. The second square through holes and the first slots are matched with the dimensions of the insert plate. When in use, the insert plate is inserted into the outer frame through the second square through hole and the first slot to fix and cover the first square through hole. After insertion, the distance between the inner sides of a pair of insert plates is the third dimension; the distance between the inner sides of the second and fourth sides is the first dimension; the first dimension and the second dimension are respectively consistent with the two side lengths of the graphene film; the upper plate is provided with a threaded hole that mates with the screw, and the screw is fixed to the outer frame through the threaded hole; the pressure head is provided at the lower end of the screw, and the side length of the curved edge of the pressure head and the curved substrate is the first dimension, and the side length of the straight edge of the curved substrate is the third dimension.

[0009] Furthermore, the material of the arc-shaped substrate is stainless steel, pure titanium, or Teflon.

[0010] Furthermore, the insert plate is made of a transparent material.

[0011] Furthermore, several first plates have different heights and widths of a first dimension.

[0012] Furthermore, a through hole is provided between the second and fourth sides to facilitate the discharge of the polymer matrix precursor.

[0013] Furthermore, the bottom of the second and fourth sides is provided with a fourth square through hole for easy removal of the block. The device also includes a pad and several second plates. The side lengths of the second plates are the first dimension and the third dimension, respectively. The width of the pad is smaller than the width of the fourth square through hole, the height of the pad is smaller than the height of the fourth square through hole, and the sum of the height of the pad and the thickness of the second plates is greater than the height of the fourth square through hole.

[0014] A method of using the vertical thermal interface material matrix content control device includes: Place the device horizontally with the first side facing upwards; Insert a plug into the first slot corresponding to the third side; Insert the first plate through the first square through hole, and insert several inserts in sequence along the third square through hole above the third side of the first plate to the required height; Several graphene films coated or soaked with polymer matrix precursors are stacked by inserting them through the first square through hole; After stacking, an arc-shaped substrate is placed between the graphene film and the pressure head, with the arc edges of the arc-shaped substrate facing the first side and the third side respectively; then another first plate is placed on top of the stacked graphene film, and several inserts are sequentially inserted to the required height along the third-shaped through hole below the first side in front of the first plate, and an insert plate is inserted into the first slot corresponding to the first side. Place the device vertically, adjust the arc-shaped substrate to be centered, and then press down the pressure head by rotating the screw while pulling out the insert. Continue pressing down after all the inserts are pulled out. With the support of the first plates on both sides, the arc-shaped substrate gradually flattens out, allowing the polymer matrix precursor to overflow from the middle to the edge until it is completely flattened to the required height. Control the polymer matrix content in the vertical thermal interface material after curing to be 12%~20%.

[0015] The beneficial effects of this invention are that it can control the content of polymer matrix in the cured vertical thermal interface material to be 12%~20%, and achieve good adhesion of graphene film through the polymer between graphene film layers. Further cutting yields graphene vertical thermal interface material with certain strength, low surface adhesive residue, bright surface, low contact thermal resistance, and good uniformity. Attached Figure Description

[0016] The present invention will be further described below with reference to the accompanying drawings and embodiments; Figure 1 This is an overall structural diagram of a vertical thermal interface material matrix content control device according to an embodiment of the present invention; Figure 2 This is a cross-sectional view of the vertical thermal interface material matrix content control device according to an embodiment of the present invention along the vertical direction. Figure 3 This is a cross-sectional view of the vertical thermal interface material matrix content control device according to an embodiment of the present invention along the horizontal direction. Figure 4 This is a structural diagram of the arc-shaped substrate 6 of the present invention; Figure 5 This is an overall structural diagram of a vertical thermal interface material matrix content control device according to another embodiment of the present invention; Figure 6 This is a photograph of the vertical thermal interface material prepared in Example 1 of the present invention. Figure 7 This is a scanning electron microscope image of the surface of the vertical thermal interface material prepared in Example 1 of the present invention; Figure 8 This is a scanning electron microscope (SEM) image of the cross-section of the vertical thermal interface material prepared in Example 1 of the present invention; Figure 9 This is a physical image of the vertical thermal interface material prepared according to the comparative example of this invention; Figure 10 This is a scanning electron microscope image of the surface of the vertical thermal interface material prepared in the comparative example of this invention; In the figure, the outer frame 1, pressure head 2, screw 3, insert plate 4, insert strip 5, arc-shaped base plate 6, first flat plate 7, rectangular frame 8, upper plate 9, lower plate 10, first side 8-1, second side 8-2, third side 8-3, fourth side 8-4, first square through hole 11, first slot 12, second square through hole 13, third square through hole 14, second dimension 15, third dimension 16, first dimension 17, fourth square through hole 18, pad block 19, second flat plate 20, and fifth square through hole 21. Detailed Implementation

[0017] The present invention will be further described below with reference to specific embodiments: This invention provides a device for controlling the matrix content of vertical thermal interface materials, such as... Figure 1-3As shown, the device mainly includes an outer frame 1, a pressure head 2, a screw 3, a pair of insert plates 4, several insert strips 5, an arc-shaped base plate 6, and several first flat plates 7. The outer frame 1 is composed of a rectangular frame and an upper plate 9 and a lower plate 10 disposed at the upper and lower parts of the rectangular frame. Among the four sides of the rectangular frame, the first side 8-1 is opposite to the third side 8-3, and the second side 8-2 is opposite to the fourth side 8-4. The first side 8-1 and the third side 8-3 have the same structure, and each is provided with a first square through hole 11 in the middle. The width of the first square through hole 11 is the first dimension 17; the second side 8-2 and the fourth side 8-4 have the same structure, with symmetrical third square through holes 14 on both the left and right sides along the length direction. The width of the third square through hole 14 matches the thickness of the insert 5 and the first plate 7. In use, several inserts 5 are fixed by inserting them into the third square through holes 14. After insertion, the distance between the inner sides of the inserts 5 on the left and right sides is the second dimension 15; the distance between the inner sides of the second side 8-2 and the fourth side 8-4 is the first dimension 17; the second side 8-2 and The inner side of the fourth side 8-4 is provided with first slots 12 that connect from top to bottom on both sides along the length of the first square through hole 11. The upper plate 9 is provided with corresponding second square through holes 13. The second square through holes 13 and the first slots 12 are matched with the dimensions of the insert plate 4. In use, the insert plate 4 is inserted into the outer frame 1 through the second square through holes 13 and the first slots 12 to fix and cover the first square through hole 11. After insertion, the distance between the inner sides of a pair of insert plates 4 is the third dimension 16. The first dimension 17 and the second dimension 15 are respectively aligned with the two edges of the graphene film. The lengths are consistent; the upper plate 9 is provided with a threaded hole that mates with the screw 3, and the screw 3 is fixed to the outer frame 1 through the threaded hole; the pressure head 2 is located at the lower end of the screw 3, and the two side lengths of the pressure head 2 and the arc-shaped base plate 6 are the first dimension 17 and the third dimension 16, respectively. They cooperate with the space formed by the second side 8-2, the fourth side 8-4, and the inner sides of the left and right insert strips 5 after insertion, allowing the pressure head 2 and the arc-shaped base plate 6 to move within this space in a restricted manner. The arc-shaped side of the arc-shaped base plate 6 has a side length of the first dimension 17, and the straight side has a side length of the third dimension 16. Figure 4 As shown.

[0018] In one specific implementation, the rectangular frame can be a single piece or assembled from four panels. Figure 1-2 The diagram shows a structure consisting of four plates assembled with bolts.

[0019] In one specific implementation, the arc-shaped substrate 6 is made of a material such as stainless steel, pure titanium, or Teflon, which has a certain rigidity and is easy to deform and flatten, so that it maintains its arc shape during the pressing process and deforms and flattens after being pressed to a certain height. In this embodiment, stainless steel with a thickness of 1 mm is preferred.

[0020] In one specific implementation, the insert plate 4 is made of a transparent material, such as an acrylic sheet, to facilitate observation during the pressing process.

[0021] In one specific implementation, the width of the plurality of first plates 7 is all of the first dimension 17, which facilitates insertion and removal through the first square through hole 11. The plurality of first plates 7 have different heights to accommodate different sample height requirements.

[0022] In one specific embodiment, a through-hole is further provided between the second side 8-2 and the fourth side 8-4 to facilitate the discharge of the polymer matrix precursor. This through-hole can be of any shape, one or more, as described in a more specific embodiment, such as... Figure 5 As shown, the through hole is a fifth square through hole 21. The width of the through hole is smaller than the second dimension 15, generally 1 / 4 to 3 / 4 of the second dimension 15. While facilitating glue discharge, it can effectively fix the film and prevent it from sliding out from the edge during the pressing process.

[0023] In one specific embodiment, the bottom of the second side 8-2 and the fourth side 8-4 are further provided with a fourth square through hole 18, such as... Figure 5 As shown, the device also includes a pad 19 and several second plates 20. The side lengths of the second plates 20 are a first dimension 17 and a third dimension 16, respectively. The width of the pad 19 is smaller than the width of the fourth square through hole 18, the height of the pad 19 is smaller than the height of the fourth square through hole 18, and the sum of the height of the pad 19 and the thickness of the second plates 20 is greater than the height of the fourth square through hole 18 to prevent the second plates 20 from sliding. In use, the pad 19 is placed in the device, then the second plates 20 are placed on top, and the membrane material is placed in; then it is pressed down and cured; after curing, the pad 19 is removed, and the graphene block can be lowered and taken out through the fourth square through hole 18. Generally, the second plates 20 can be placed on both the top and bottom sides of the membrane to facilitate the shaping of the graphene membrane before curing and its separation from the pressure head after curing.

[0024] In one specific embodiment, the viscosity of the polymer matrix precursor is 20 to 1500 viscosity. The polymer can be silicone, polyurethane, etc., with silicone being preferred. In a more specific embodiment, an addition-type liquid silicone rubber is used, whose unique reaction principle is: under the action of a platinum catalyst, the base polymer (containing vinyl groups) and the crosslinking agent (containing silane bonds) undergo an addition reaction, vulcanizing into an elastomer. This reaction process has no byproducts, thus having the outstanding advantages of extremely low shrinkage (<0.1%) and deep curing capability. Generally, the base polymer can be vinyl silicone oil (such as polymethylvinylsiloxane), the crosslinking agent can be hydrogen-containing silicone oil (polymethylhydrosiloxane), and the platinum catalyst can be a platinum catalyst. To control the curing speed and extend the operating time at room temperature, inhibitors and alkynyl alcohol compounds (such as 1-ethynyl-1-cyclohexanol, ethynylcyclohexanol) can also be added to ensure that the rubber compound has sufficient time for mixing and pouring, and then rapidly vulcanized by heating. Generally, the amount of vinyl silicone oil (such as polymethylvinylsiloxane) is 100 parts, the amount of hydrogen-containing silicone oil (polymethylhydrosiloxane) is 1-10 parts, the amount of platinum catalyst (such as chloroplatinic acid-isopropanol complex) is 10-40 ppm, and the amount of inhibitor is 0.01-0.1 parts. The hydrogen-containing silicone oil molecule must have at least three Si-H bonds. It can be a "side-containing hydrogen" type of hydrogen-containing silicone oil with randomly distributed hydrogen groups on the main chain, or an end-containing hydrogen-containing silicone oil with active groups only at both ends of the molecular chain, or a mixture of the two. The amounts used must be precisely controlled, usually with a slight excess of the molar ratio of Si-H to Si-Vi (silane-hydrogen group and silane-vinyl group) (generally between 1.2:1 and 2:1) to ensure complete reaction.

[0025] A method of using a vertical thermal interface material matrix content control device according to the present invention includes: Place the device horizontally with the first side 8-1 facing upwards; Insert a plug 4 into the first slot 12 corresponding to the third side 8-3; The first plate 7 is inserted through the first square through hole 11, and several inserts 5 are sequentially inserted into the third square through hole 14 above the third side 8-3 in front of the first plate 7 to the required height. Several graphene films coated or soaked with polymer matrix precursors are placed and stacked through the first square through-hole 11; After stacking, an arc-shaped substrate 6 is placed between the graphene film and the pressure head 2, wherein the arc-shaped edges of the arc-shaped substrate 6 face the first side 8-1 and the third side 8-3, respectively. Figure 2 , 5 As shown; then another first plate 7 is placed on top of the stacked graphene film, and several inserts 5 are sequentially inserted into the third-dimensional through hole 14 below the first side 8-1 in front of the first plate 7 to the required height, and another insert plate 4 is inserted into the first slot 12 corresponding to the first side 8-1. Place the device vertically, such as Figure 2 As shown, after adjusting the arc-shaped substrate 6 to be centered, the screw 3 is rotated to press down the head 2 while pulling out the insert 5. After all the inserts 5 are pulled out, the pressure continues to be applied. With the support of the first plates 7 on both sides, the arc-shaped substrate 6 gradually flattens out, causing the polymer matrix precursor to overflow from the middle to the edge until it is completely flattened to the required height. The polymer matrix content in the vertical thermal interface material after curing is controlled to be 12%~20%.

[0026] This invention allows for the controllability of the polymer matrix content in the cured vertical thermal interface material to be 12%~20%. Further cutting yields graphene vertical thermal interface materials with low adhesive residue, a glossy surface, low contact thermal resistance, and good uniformity. The effects of this invention are further illustrated below with specific embodiments: Example 1:

[0027] Prepare a silicone rubber matrix precursor solution containing 300 parts of 100 viscosity vinyl silicone oil (vinyl content 1.03%), 86 parts of hydrogen-terminated silicone oil (hydrogen content 0.11%), 2.9 parts of low-hydrogen silicone oil (hydrogen content 1.04%), 1.4 parts of silicone inhibitor and 20 ppm platinum catalyst. After preparation, stir and mix evenly. Place the device horizontally with the first side 8-1 facing upwards; Insert a plug 4 into the first slot 12 corresponding to the third side 8-3; The first plate 7 is inserted through the first square through hole 11. The first plate 7 is parallel to the insert plate 4. Several insert strips 5 are inserted sequentially to the required height along the third square through hole 14 above the third side 8-3 in front of the first plate 7. After soaking the 4cm*5cm graphene film in the silicone rubber precursor solution, it is taken out, aligned, and placed into the device through the first square through hole 11 for stacking. In this embodiment, the graphene film size is 4cm*5cm, that is, the first size is 5cm, the second size is 4cm, and the third size is the second size + 2 * the width of the insert. In this embodiment, the width of the insert is 5mm, so the third size is also 5cm. After stacking, an arc-shaped substrate 6 is placed between the graphene film and the pressure head 2, wherein the arc-shaped edges of the arc-shaped substrate 6 face the first side 8-1 and the third side 8-3 respectively. Then, another first plate 7 is placed on top of the stacked graphene film, and several inserts 5 are inserted sequentially to the required height along the third square through hole 14 below the first side 8-1 in front of the first plate 7. An insert plate 4 is inserted into the first slot 12 corresponding to the first side 8-1. Place the device vertically, such as Figure 2 , 5As shown, after centering the arc-shaped substrate 6, the screw 3 is rotated to press down the pressure head 2 while pulling out the insert 5. After all inserts 5 are pulled out, the pressure continues. Supported by the first plates 7 on both sides, the arc-shaped substrate 6 gradually flattens, causing the polymer matrix precursor to overflow from the center to the edge until it is completely flattened to the required height. Then, it is heated at 80℃ for 1 hour to cure the silicone rubber. After curing, the block is removed. Based on the increase in adhesive weight divided by the total weight of the block, the silicone content in the cured vertical thermal interface material is calculated to be 16%, and the graphene skeleton density is 0.4 (the graphene film weight before adhesive filling is 28g, and the height of the graphene block after filling is 3.5cm). The block is then cut into 600μm gaskets perpendicular to the graphene stacking direction using a wire cutting device, with the appearance as shown. Figure 6 As shown, the microscopic surface is as follows Figure 7-8 As shown, the surface is glossy, with no obvious glue residue and no interlayer cracks. The thermal resistance, measured using a thermal resistance tester (Ruiling), is 0.073℃·cm. 2 / W.

[0028] Example 2:

[0029] Prepare a silicone rubber matrix precursor solution containing 300 parts of 25 viscosity vinyl silicone oil (vinyl content 2.73%), 262.7 parts of hydrogen-terminated silicone oil (hydrogen content 0.11%), 9.63 parts of low-hydrogen silicone oil (hydrogen content 1.04%), 8 parts of silicone inhibitor and 30 ppm platinum catalyst. After preparation, stir and mix evenly. The other steps are the same as in Example 1. Based on the increase in adhesive content, the silicone content in the cured vertical thermal interface material is calculated to be 13.7%, and the graphene framework density is 0.4. The block is cut into 600μm gaskets perpendicular to the graphene stacking direction using a wire cutting device. The surface is glossy, with no obvious adhesive residue, and no interlayer cracking. The thermal resistance is measured to be 0.07℃·cm using a thermal resistance tester (Ruiling). 2 / W.

[0030] Example 3:

[0031] Prepare a silicone rubber matrix precursor solution containing 300 parts of 300 viscosity vinyl silicone oil (vinyl content 0.56%), 55 parts of hydrogen-terminated silicone oil (hydrogen content 0.11%), 1.83 parts of low-hydrogen silicone oil (hydrogen content 1.04%), 1.4 parts of silicone inhibitor and 30 ppm of platinum catalyst. After preparation, stir and mix evenly. The other steps are the same as in Example 1. Based on the increase in adhesive content, the silicone content in the cured vertical thermal interface material is calculated to be 20%, and the graphene framework density is 0.4. The block is cut into 600μm gaskets perpendicular to the graphene stacking direction using a wire cutting device. The surface is glossy, with no obvious adhesive residue, and no interlayer cracking. The thermal resistance is measured to be 0.075℃·cm using a thermal resistance tester (Ruiling). 2 / W.

[0032] Example 4:

[0033] The other steps are the same as in Example 1, except that the block is cut into 300μm gaskets perpendicular to the graphene stacking direction using a wire cutting device. The surface is bright, with no obvious adhesive residue, and no interlayer cracking. The thermal resistance is measured to be 0.065℃·cm using a thermal resistance tester (Ruiling). 2 / W.

[0034] Comparative example: Prepare a silicone rubber matrix precursor solution containing 300 parts of 100 viscosity vinyl silicone oil (vinyl content 1.03%), 86 parts of hydrogen-terminated silicone oil (hydrogen content 0.11%), 2.9 parts of low-hydrogen silicone oil (hydrogen content 1.04%), 1.4 parts of silicone inhibitor and 20 ppm platinum catalyst. After preparation, stir and mix evenly. After immersing the cut graphene film in a silicone rubber precursor solution, it was removed, aligned, and placed into a standard limiting compression device for compression and adhesive removal to achieve the desired height. Subsequently, it was heated at 80℃ for 1 hour to cure the silicone rubber. After curing, the block was removed, and based on the increase in adhesive content, the silicone content in the cured vertical thermal interface material was calculated to be 44.7%, and the graphene framework density was 0.4. The block was then cut into 600μm gaskets perpendicular to the graphene stacking direction using a wire cutting device, with an appearance as shown... Figure 9 As shown, the microscopic surface is as follows Figure 10 As shown, there is a lot of adhesive residue, and the debris from the wire-cut graphene adheres to the surface, making it appear very black. The thermal resistance, measured using a thermal resistance tester (Ruiling), is 0.12℃·cm. 2 / W.

[0035] The above embodiments are used to explain and illustrate the present invention, but not to limit the present invention. Any modifications and changes made to the present invention within the spirit and scope of the claims shall fall within the protection scope of the present invention.

Claims

1. A method for controlling the matrix content of a vertical thermal interface material, characterized in that, An arc-shaped substrate is placed on the surface of several graphene films coated or soaked with polymer matrix precursors, and then compressed to the required height. The arc-shaped substrate is then flattened to allow the polymer matrix precursors to overflow from the center to the edge. The polymer matrix content in the vertical thermal interface material after curing is controlled to be 12%~20%.

2. The method according to claim 1, characterized in that, The arc-shaped substrate is made of stainless steel, pure titanium, or Teflon.

3. The method according to claim 1, characterized in that, The viscosity of the polymer matrix precursor is 20 to 1500.

4. A device for controlling the matrix content of a vertical thermal interface material, characterized in that, The device mainly includes an outer frame, a pressure head, a screw, a pair of insert plates, several insert strips, an arc-shaped base plate, and several first flat plates. The outer frame consists of a rectangular frame and upper and lower plates located at the top and bottom of the rectangular frame. Of the four sides of the rectangular frame, the first side is opposite to the third side, and the second side is opposite to the fourth side. The first and third sides have the same structure, each with a first square through hole in the middle, the width of which is a first dimension. The second and fourth sides have the same structure, with symmetrical third square through holes along their length on both the left and right sides. The width of the third square through holes matches the thickness of the insert strips and the first flat plates. In use, several insert strips are fixed by being inserted into the third square through holes. After insertion, the distance between the inner sides of the insert strips on the left and right sides is [missing information]. The second dimension; the inner sides of the second and fourth sides are respectively provided with first slots that connect from top to bottom along the length direction of the first square through hole, and the upper plate is provided with corresponding second square through holes at opposite positions. The second square through holes and the first slots are matched with the dimensions of the insert plate. In use, the insert plate is inserted into the outer frame through the second square through hole and the first slot to fix and cover the first square through hole. After insertion, the distance between the inner sides of a pair of insert plates is the third dimension; the distance between the inner sides of the second and fourth sides is the first dimension; the first dimension and the second dimension are respectively consistent with the two side lengths of the graphene film; the upper plate is provided with a threaded hole that matches the screw, and the screw is fixed to the outer frame through the threaded hole; the pressure head is provided at the lower end of the screw, and the side length of the curved edge of the pressure head and the curved substrate is the first dimension, and the side length of the straight edge of the curved substrate is the third dimension.

5. The apparatus according to claim 4, characterized in that, The arc-shaped substrate is made of stainless steel, pure titanium, or Teflon.

6. The apparatus according to claim 4, characterized in that, The insert plate is made of a transparent material.

7. The apparatus according to claim 4, characterized in that, Several first plates have different heights and a width of a first dimension.

8. The apparatus according to claim 4, characterized in that, The second and fourth sides are also provided with a through hole to facilitate the discharge of the polymer matrix precursor.

9. The apparatus according to claim 4, characterized in that, The bottom of the second and fourth sides is also provided with a fourth square through hole for easy removal of the block. The device also includes a pad and several second plates. The side lengths of the second plates are the first dimension and the third dimension, respectively. The width of the pad is smaller than the width of the fourth square through hole, the height of the pad is smaller than the height of the fourth square through hole, and the sum of the height of the pad and the thickness of the second plate is greater than the height of the fourth square through hole.

10. A method of using the vertical thermal interface material matrix content control device according to any one of claims 4-9, characterized in that, include: Place the device horizontally with the first side facing upwards; Insert a plug into the first slot corresponding to the third side; Insert the first plate through the first square through hole, and insert several insert strips in sequence along the third square through hole above the third side of the first plate to the required height; Several graphene films coated or soaked with polymer matrix precursors are stacked by inserting them through the first square through hole; After stacking, an arc-shaped substrate is placed between the graphene film and the pressure head, with the arc edges of the arc-shaped substrate facing the first side and the third side respectively; then another first plate is placed on top of the stacked graphene film, and several inserts are sequentially inserted to the required height along the third-shaped through hole below the first side in front of the first plate, and an insert plate is inserted into the first slot corresponding to the first side. Place the device vertically, adjust the arc-shaped substrate to be centered, and then press down the pressure head by rotating the screw while pulling out the insert. Continue pressing down after all the inserts are pulled out. With the support of the first plates on both sides, the arc-shaped substrate gradually flattens out, allowing the polymer matrix precursor to overflow from the middle to the edge until it is completely flattened to the required height. Control the polymer matrix content in the vertical thermal interface material after curing to be 12%~20%.

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