Manufacturing method for graphene thermally conductive gasket and use thereof
Patent Information
- Application Number
- PCT/CN2025/144533
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2025-02-21
- Filing Date
- 2025-12-23
- Publication Date
- 2026-08-27
Smart Images
Figure PCTCN2025144533-FTAPPB-I100001 
Figure PCTCN2025144533-FTAPPB-I100002 
Figure PCTCN2025144533-FTAPPB-I100003
Abstract
Description
A method for preparing a graphene thermal pad and its application Technical Field
[0001] This application relates to the field of graphene thermal conductivity technology, and in particular to a method for preparing a graphene thermally conductive pad and its application. Background Technology
[0002] Graphene thermal pads are thermal interface materials used to improve thermal conduction between electronic components and heat sinks. They are made of graphene, a single layer of carbon atoms arranged in a honeycomb lattice, which has excellent thermal conductivity. They are typically thin and flexible sheets placed between thermal resistors (CPUs) and heat sinks to quickly transfer heat from the components to the heat sink. These properties make them widely used in electronic devices.
[0003] Thermal interface materials, or TIMs for short, are widely used in IC packaging and electronic heat dissipation. They are primarily used to fill micro-gaps and surface irregularities created when two materials meet or come into contact, reducing thermal resistance and improving device heat dissipation performance. Thermal interface heat transfer typically uses thin, flexible sheets placed between the thermally resistive component (CPU) and the heatsink. These sheets offer high thermal conductivity, good compressibility, and resilience, rapidly transferring heat from the component to the heatsink, making them widely applicable in electronic devices.
[0004] Currently, high thermal conductivity thermal interface materials include liquid metal (40-50 W / (m*k)) and thermal grease (below 10 W / (m*k)). Liquid metal is prone to corroding the contacting metal surface, and heat sinks, primarily made of aluminum, cannot maintain stable contact over long periods. Thermal grease not only has insufficient thermal conductivity, but with prolonged use, the low molecular weight silicone oil evaporates, causing the colloid to dry and crack, leading to a rapid increase in interfacial thermal resistance. Therefore, a higher-performance thermal pad is urgently needed.
[0005] Application content
[0006] The main objective of this application is to propose a method for preparing graphene thermal pads and their applications, aiming to improve the strength of graphene thermal pads while also taking into account thermal conductivity and resilience.
[0007] To achieve the above objectives, this application proposes a method for preparing a graphene thermal pad, the preparation steps of which include:
[0008] S10, provides multiple graphene foams;
[0009] S20. Remove the surface hard skin from multiple graphene foams, perform laser drilling and edge cutting, and plasma activation to obtain activated graphene foam. Then, perform a first modification treatment on the activated graphene foam with hydroxyl vinyl silicone oil to obtain multiple first graphene foams.
[0010] S30. A second modification treatment is performed on multiple first graphene foams and adhesives to obtain multiple second graphene foams.
[0011] S40. Multiple second graphene foams are bonded together along the thickness direction and pressed into blocks, then cured to obtain third graphene foam.
[0012] S50. The third graphene foam is cut into sheets along the thickness direction to obtain a graphene thermal pad, wherein the adhesive includes: linear low molecular weight vinyl silicone oil, linear medium molecular weight vinyl silicone oil, linear high molecular weight vinyl silicone oil, crosslinking agent, chain extender, reinforcing agent, toughening agent, catalyst and inhibitor.
[0013] In one embodiment, in step S10:
[0014] The graphene foam has an average density of 0.15-0.25 g / cm³. 3 ; and / or,
[0015] The thermal diffusivity of the graphene foam is ≥600 mm. 2 / s; and / or,
[0016] The thickness of the graphene foam is 200-300 μm.
[0017] In one embodiment, in step S20:
[0018] The step of removing the surface hard skin includes: breaking up and adhering the surface hard skin to remove it; and / or,
[0019] After the laser drilling and edge trimming step, the average hole diameter is 10–200 μm, and the distance between the holes is 100–4000 μm; and / or,
[0020] The plasma activation treatment step includes: processing with a direct-injection plasma activation treatment device; and / or,
[0021] The first modification treatment step includes: coating the activated graphene foam with xylene-diluted hydroxyvinyl silicone oil, and after complete absorption, vacuum heating treatment is performed to obtain multiple first graphene foams. The coating is: 3 to 9 mg of hydroxyvinyl silicone oil is sprayed onto each square centimeter of the activated graphene foam.
[0022] In one embodiment, in step S30, the second modification process includes: spraying the adhesive onto the plurality of first graphene foams and mixing them to obtain a plurality of second graphene foams, wherein the spraying is: 70 to 110 mg of adhesive is sprayed onto each square centimeter of first graphene foam.
[0023] In one embodiment, the adhesive comprises linear low molecular weight vinyl silicone oil, linear medium molecular weight vinyl silicone oil, linear high molecular weight vinyl silicone oil, crosslinking agent, chain extender, reinforcing agent, toughening agent, catalyst, and inhibitor, wherein the linear low molecular weight vinyl silicone oil is 50 cp vinyl silicone oil, the linear medium molecular weight vinyl silicone oil is 500 cp vinyl silicone oil, and the linear high molecular weight vinyl silicone oil is 2 w cp vinyl silicone oil.
[0024] The mass ratio of the 50cp vinyl silicone oil, the 500cp vinyl silicone oil, the 2wcp vinyl silicone oil, the chain extender, the crosslinking agent, the reinforcing agent, the toughening agent, the catalyst, and the inhibitor is (20-50):(60-130):(30-50):(15-25):(20-30):(3-5):(0.5-1.5):(0.3-0.6):(0.08-0.12); and / or,
[0025] The mass ratio of the first graphene foam to the adhesive is 1:(1-3).
[0026] In one embodiment, in the adhesive:
[0027] The linear low molecular weight vinyl silicone oil includes low molecular weight silicone oils with a viscosity below 500 cp; and / or,
[0028] The linear medium molecular weight vinyl silicone oil includes medium molecular weight silicone oils with a viscosity of 500 cp to 5000 cp; and / or,
[0029] The linear high molecular weight vinyl silicone oil includes high molecular weight silicone oils with a viscosity of 5000 cp or higher; and / or,
[0030] The crosslinking agent includes hydrosilicone oil; and / or,
[0031] The chain extender includes hydrogen-terminated silicone oil; and / or,
[0032] The reinforcing agent includes MQ resin; and / or,
[0033] The toughening agent includes nano-sized fumed silica; and / or...
[0034] The catalyst includes a platinum catalyst; and / or,
[0035] The inhibitors include ethynol inhibitors.
[0036] In one embodiment, the preparation step of the adhesive includes mixing the linear low molecular weight vinyl silicone oil, the linear medium molecular weight vinyl silicone oil, the linear high molecular weight vinyl silicone oil, the crosslinking agent, the chain extender, the catalyst, the inhibitor, the reinforcing agent, and the toughening agent.
[0037] In one embodiment, in step S40, the thickness of the third graphene foam is 40-50 mm; and / or,
[0038] In step S50, the thickness of the graphene thermal pad is 0.3 to 2.0 mm.
[0039] This application also provides a graphene thermal pad, which includes a graphene thermal pad prepared by the method described above.
[0040] The technical solution of this application provides a method for preparing a graphene thermal conductive pad. The graphene thermal conductive pad uses graphene foam as the base material. Through surface skin removal, laser drilling and edge cutting, plasma activation treatment, and multiple modification treatments, the graphene surface generated by plasma activation treatment is rich in hydroxyl functional groups. Through hydroxyl vinyl silicone oil, a small amount of hydroxyl vinyl silicone oil is evenly covered on the graphene surface. Heating causes the hydroxyl vinyl silicone oil and the hydroxyl groups after plasma activation treatment to undergo dehydration condensation and form chemical bonds. This makes the interface between graphene and subsequent adhesives more compact, reduces the porosity at the interface, thereby reducing thermal resistance, improving heat transfer efficiency, and also improving tensile strength and compression resilience. Detailed Implementation
[0041] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Where the manufacturers of reagents or instruments are not specified, they are all conventional products that can be purchased commercially. Furthermore, the meaning of "and / or" throughout the text includes three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied. In addition, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0042] Graphene thermal pads are thermal interface materials used to improve thermal conduction between electronic components and heat sinks. They are made of graphene, a single layer of carbon atoms arranged in a honeycomb lattice, which has excellent thermal conductivity. They are typically thin and flexible sheets placed between thermal resistors (CPUs) and heat sinks to quickly transfer heat from the components to the heat sink. These properties make them widely used in electronic devices.
[0043] Currently, high thermal conductivity interface materials include liquid metal (40-50 W / (m*k)) and thermal grease (below 10 W / (m*k)). Liquid metal is prone to corroding the contacting metal surface, and heat sinks, primarily made of aluminum, cannot maintain stable contact over long periods. Thermal grease not only has insufficient thermal conductivity, but with prolonged use, the low molecular weight silicone oil evaporates, causing the colloid to dry and crack, leading to a rapid increase in interfacial thermal resistance.
[0044] In view of this, to achieve the above objectives, this application provides a method for preparing a graphene thermal pad, the preparation steps of which include:
[0045] S10, provides multiple graphene foams;
[0046] S20. Remove the surface hard skin from multiple graphene foams, perform laser drilling and edge cutting, and plasma activation to obtain activated graphene foam. Then, perform a first modification treatment on the activated graphene foam with hydroxyl vinyl silicone oil to obtain multiple first graphene foams.
[0047] S30. A second modification treatment is performed on multiple first graphene foams and adhesives to obtain multiple second graphene foams.
[0048] S40. Multiple second graphene foams are bonded together along the thickness direction and pressed into blocks, then cured to obtain third graphene foam.
[0049] S50. The third graphene foam is cut into sheets along the thickness direction to obtain a graphene thermal pad, wherein the adhesive includes: linear low molecular weight vinyl silicone oil, linear medium molecular weight vinyl silicone oil, linear high molecular weight vinyl silicone oil, crosslinking agent, chain extender, reinforcing agent, toughening agent, catalyst and inhibitor.
[0050] In the technical solution of this application, the graphene thermal pad uses graphene foam as the base material. Through surface skin removal, laser drilling and edge cutting, plasma activation treatment, and multiple modification treatments, the thermal pad can make better contact with the component and effectively fill the air gap. This not only significantly improves the heat transfer efficiency, but also improves the tensile strength and compression resilience.
[0051] Furthermore, in step S20, the plasma activation treatment generates hydroxyl-rich functional groups on the graphene surface. The hydroxyl vinyl silicone oil diluted with xylene reduces the viscosity of the silicone oil, allowing it to uniformly cover the graphene surface. Heating causes the hydroxyl vinyl silicone oil to undergo dehydration condensation with the hydroxyl groups after plasma activation, forming chemical bonds. This makes the interface between the graphene and the subsequent adhesive tighter, reduces porosity at the interface, thereby reducing thermal resistance, improving heat transfer efficiency, and also improving tensile strength and compression resilience.
[0052] In some embodiments of this application, step S10 involves providing a plurality of graphene foams;
[0053] Graphene foam is a three-dimensional porous material composed of graphene or its derivatives, with a structure similar to a sponge. This material combines the unique physicochemical properties of graphene with the lightweight and high specific surface area characteristics of foam materials, and its high thermal conductivity makes it a suitable base material for graphene thermal pads.
[0054] Further, in step S10: the average density of the graphene foam is 0.2-0.3 g / cm³. 3 Within this density range, graphene foam exhibits high flexibility and thermal conductivity; the thermal diffusivity of the graphene foam is ≥600 mm². 2 / s; The thickness of the graphene foam is 200-300μm. Higher density results in a higher thermal diffusivity but reduced flexibility. A density of 0.2-0.3 g / cm³ is chosen to balance thermal conductivity and flexibility. 3 The sample. Thicker foam has higher production costs, fewer graphene interfaces, and thus improved crack resistance. A thickness of 200-300μm is chosen to balance cost and performance.
[0055] In some embodiments of this application, step S20, the step of removing the surface hard skin, includes: breaking and adhering the surface hard skin to remove it.
[0056] Specifically, the surface hardening removal step is performed as follows: The laser focusing focal length of the laser drilling machine is adjusted, and the laser scans the sample surface at an appropriate speed. During laser irradiation, the surface softens due to localized heat, and upon laser removal, it becomes brittle due to cooling. Thermal expansion and contraction cause the surface hardening to shatter into small pieces, preventing damage to the internal foam during subsequent removal. Next, a double-roller press is adjusted so that the distance between the rollers matches the graphene foam. Double-sided tape is evenly applied to the outside of the rollers to facilitate subsequent hardening removal. The graphene foam is horizontally inserted between the rollers from one side, and the adhesion of the double-sided tape effectively removes the fragmented hardening from the graphene surface. The double-sided tape is repeatedly replaced to remove the hardening from all the required graphene foam. Although the surface hardening has a high thermal conductivity, its high hardness when vertically arranged and its brittle fracture under stress indicate a lack of flexibility.
[0057] In some embodiments of this application, in the laser drilling and edge trimming step, the average diameter of the hole is 10-200 μm and the distance between the holes is 100-4000 μm.
[0058] Understandably, during the fabrication of graphene foam, the outermost layer loses moisture or heat faster than the interior. This results in a denser surface with fewer pores compared to the interior. Furthermore, coated graphene foam has a low density, necessitating the use of a rolling mill to increase density and thermal conductivity. The uneven stress distribution between the outer and inner layers during rolling further contributes to the higher density, crystallinity, and hardness of the outer graphene. This creates a relatively dense "skin," which is prone to breakage under stress, disrupting heat conduction pathways and reducing thermal conductivity. The denser surface also reduces the flexibility of the graphene foam, preventing it from rebounding to a certain height after stress relief. Removing this layer would make the graphene foam more flexible, allowing it to better conform to the uneven surfaces of electronic components. This ensures lower contact thermal resistance and minimizes air gaps that hinder heat conduction.
[0059] In some embodiments of this application, step S20, the laser drilling and trimming step includes: laser drilling and trimming the edges by placing multiple graphene foams on a laser drilling platform. The purpose of laser drilling is to provide channels for subsequent reactants to enter the interior of the graphene foam, so as to facilitate subsequent reactions.
[0060] Furthermore, in step S20, the plasma activation treatment step includes: using a direct-injection plasma activation treatment device for treatment, specifically including: setting a "Z" shaped route to perform plasma activation treatment on the entire surface, which can make the graphene surface uniformly activated. After plasma activation, the graphene foam has abundant hydroxyl groups on its surface, providing abundant reactive sites and enhancing the surface activity of the graphene.
[0061] In some embodiments of this application, the first modification treatment step includes: coating the activated graphene foam with xylene-diluted hydroxyvinyl silicone oil, and after complete absorption, vacuum heating treatment to obtain multiple first graphene foams. The coating is performed by spraying 3-9 mg of hydroxyvinyl silicone oil per square centimeter of the activated graphene foam. This is to allow the hydroxyl groups generated by the plasma activation treatment to react with the hydroxyl groups of the hydroxyvinyl silicone oil to form new chemical bonds. Through the reaction of hydroxyvinyl silicone oil with the hydroxyl groups on the surface of the graphene foam, stable chemical bonds are formed, which enhances the adhesion between the coating and the substrate, prevents the coating from peeling off, and improves mechanical strength and chemical stability.
[0062] In some embodiments of this application, step S30 includes the second modification process: mixing and spraying the adhesive with the plurality of first graphene foams to obtain a plurality of second graphene foams. The spraying process involves spraying 70 to 110 mg of adhesive per square centimeter of first graphene foam. Here, the performance of the graphene foam is improved by spraying adhesive onto the first graphene foam.
[0063] In some embodiments of this application, the adhesive comprises linear low molecular weight vinyl silicone oil, linear medium molecular weight vinyl silicone oil, linear high molecular weight vinyl silicone oil, crosslinking agent, chain extender, reinforcing agent, toughening agent, catalyst, and inhibitor. The linear low molecular weight vinyl silicone oil is 50 cp vinyl silicone oil, the linear medium molecular weight vinyl silicone oil is 500 cp vinyl silicone oil, and the linear high molecular weight vinyl silicone oil is 2 w cp vinyl silicone oil.
[0064] The mass ratio of the 50cp vinyl silicone oil, the 500cp vinyl silicone oil, the 2wcp vinyl silicone oil, the chain extender, the crosslinking agent, the reinforcing agent, the toughening agent, the catalyst, and the inhibitor is (20-50):(60-130):(30-50):(15-25):(20-30):(3-5):(0.5-1.5):(0.3-0.6):(0.08-0.12).
[0065] In this application's technical solution, the quality of the final graphene thermal pad is improved by optimizing the strength, toughness, and surface tack of the cured adhesive. The addition of low-molecular-weight silicone oil ensures the adhesive has low viscosity, facilitating absorption by the graphene foam after spraying. Medium-molecular-weight silicone oil has a suitable molecular weight, balancing viscosity and strength. High-molecular-weight silicone oil increases the elongation at break of the adhesive. MQ resin acts as a reinforcing agent, increasing the toughness after curing. Fumed silica further enhances the toughness after curing. Within the aforementioned ratio range, the prepared adhesive exhibits better adhesion to the graphene foam, thus improving the performance of the graphene foam.
[0066] In some embodiments of this application, the mass ratio of the first graphene foam to the adhesive is 1:(1-3).
[0067] In some embodiments of this application, the adhesive includes a linear low molecular weight vinyl silicone oil with a viscosity range of less than 500 cp, which has low viscosity and abundant reactive functional groups, providing better flowability and absorption of the adhesive; a linear medium molecular weight vinyl silicone oil including a medium molecular weight silicone oil with a viscosity range of 500 cp-5000 cp, and a dual-terminated vinyl linear silicone oil with a viscosity range of more than 500 cp and less than 5000 cp, which has appropriate viscosity and appropriate reactive functional groups, providing moderate strength after curing; and a linear high molecular weight vinyl silicone oil including VS20000, which is a dual-terminated vinyl linear silicone oil with a viscosity range of more than 5000 cp, having higher viscosity and fewer reactive functional groups, providing higher strength after curing.
[0068] The crosslinking agent includes hydrosilicone oil; and / or,
[0069] The chain extender includes hydrogen-terminated silicone oil; and / or,
[0070] The reinforcing agent includes MQ resin; and / or,
[0071] The toughening agent includes nano-sized fumed silica.
[0072] In some embodiments of this application, the preparation steps of the adhesive include: mixing the linear low molecular weight vinyl silicone oil, the linear medium molecular weight vinyl silicone oil, the linear high molecular weight vinyl silicone oil, the crosslinking agent, the chain extender, the catalyst, the inhibitor, the reinforcing agent, and the toughening agent.
[0073] In some embodiments of this application, in step S40: the thickness of the third graphene foam is 40-50 mm, which can be flexibly adjusted according to testing requirements.
[0074] In some embodiments of this application, in step S50: the thickness of the graphene thermal pad is 0.3 to 2.0 mm. Within this range, the inherent high thermal conductivity of graphene is fully utilized, allowing heat to be quickly transferred from the heat source to the radiator or other cooling device, thus improving the heat exchange efficiency of the entire system. At the same time, it can adapt to contact surfaces of different shapes and sizes, ensuring good fit, reducing air gaps, and thus reducing thermal resistance.
[0075] This application also provides a graphene thermal pad, which comprises a graphene thermal pad prepared by the method described above. The graphene thermal pad possesses all the beneficial effects of the above-described preparation method, which will not be elaborated further here.
[0076] The technical solution of this application will be further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are only used to explain this application and are not intended to limit this application.
[0077] Experimental materials
[0078] The hydroxyvinyl silicone oil is sourced from Zhejiang Zhenghe 207V-2.5;
[0079] The following silicone oils are all from Anbia Specialty Silicones (Nantong) Co., Ltd. Only the specific models are listed below:
[0080] The 50cp vinyl silicone oil is designated as VS 50.
[0081] The 500cp vinyl silicone oil is designated as VS 500.
[0082] The 2w cp vinyl silicone oil is model VS20000;
[0083] The 0.2% hydrogen-terminated silicone oil is model CE 100.
[0084] The 0.34% side-hydrogen silicone oil is model XL 12;
[0085] MQ resin is derived from Konda Technology's VMQ-2709;
[0086] The nano-sized fumed silica is derived from Hubei Huifu Nanomaterials HB139.
[0087] Example 1
[0088] A method for preparing a graphene thermal conductive pad, comprising the following steps:
[0089] S10, provides 43 sheets with a thermal diffusivity of 650mm. 2 / s, density 0.2g / cm³ 3 Graphene foam with dimensions of 100*100*350mm (length*width*height);
[0090] S20. 43 sheets of the aforementioned graphene foam are adsorbed onto the surface using a vacuum stage, and a laser drilling machine is used. A 1500W laser is focused 2mm on the graphene surface to form an effective circle with a diameter of 1mm, and the laser is rapidly scanned at 10mm / s. A bonding area of equal width to the graphene foam is pasted onto a 300mm diameter roller press. After adjusting the distance between the two rollers to be the same as that of the graphene foam, the graphene foam is fed in from one side, thus removing the surface hardening layer from a portion of the area. This process is repeated to remove the hardening layer from the entire graphene surface, resulting in 43 sheets of the first graphene foam with a thickness of 300μm (±15μm) and a de-hardened surface layer.
[0091] S30. Perform laser drilling and edge trimming on 43 sheets of the first graphene foam: Place 43 sheets of the first graphene foam on a laser drilling platform and perform laser drilling and edge trimming operations simultaneously. The hole diameter is 50μm, the hole spacing is 1000μm, and the upper and lower columns are staggered by 1000μm in an A / B / A / B repeating arrangement. The trimming size is 50mm*50mm to facilitate subsequent plasma activation treatment.
[0092] The specific treatment method of plasma activation is as follows: Place the sample in a grid-framed plate, use a direct-injection plasma activation treatment device, set the power to 800w, the horizontal height of the spray gun from the sample to 10mm, and the nozzle size of the spray gun to be a circle with a diameter of 10mm. The effective treatment area is calculated to be a circle with a diameter of 20mm using the projection method. Therefore, the moving speed of the spray gun is 5mm / s, and it moves down 20mm when changing lines. Set a "Z" shaped route to perform plasma activation treatment on the entire surface to obtain activated graphene foam.
[0093] The activated graphene foam and hydroxyl vinyl silicone oil diluted 10 times with xylene were evenly sprayed onto the surface of the graphene foam using a spraying machine. The amount of spraying was controlled at 6 mg / cm³. 2 After the hydroxyvinyl silicone oil is fully absorbed, 43 sheets of first graphene foam are obtained. Next, the 43 sheets of first graphene foam undergo a second modification treatment with the adhesive. The specific steps of this treatment are as follows: the adhesive is sprayed onto the multiple first graphene foams and mixed to obtain multiple second graphene foams. The amount of adhesive sprayed is controlled so that 90 mg of adhesive is sprayed onto each square centimeter of first graphene foam. This results in 43 * 4 = 172 sheets of second graphene foam with a size of 50 * 50 mm.
[0094] S40. Place 172 sheets of the second graphene foam in the mold and stack them together. After stacking all 172 sheets, place a 50*50*5mm square aluminum block on top and bottom. Use an automatic pushing device to apply pressure to the aluminum blocks, making the graphene foam adhere tightly to each other, until the overall spacing between the aluminum blocks is 51.6mm, then lock the aluminum blocks. Place the entire device in an oven and heat at 120℃ for 2 hours to cure, obtaining the third graphene foam.
[0095] S50. Remove the third graphene foam from the oven, take it out of the module, and cut off the surface residue with a knife before placing it on the diamond cutting machine operating table. Set the cutting thickness to 300μm and cut it into sheets along the thickness direction to obtain a graphene thermal conductive pad;
[0096] The specific components and dosages of the adhesive are as follows: 20 parts 50cp vinyl silicone oil, 100 parts 500cp vinyl silicone oil, 30 parts 2wcp vinyl silicone oil, 20 parts 0.2% terminal hydrogen silicone oil, 25 parts 0.34% side hydrogen silicone oil, 4 parts MQ resin, 1 part nano-grade fumed silica, 0.5 parts 5000ppm platinum catalyst, and 0.1 parts alkynol inhibitor.
[0097] Example 2
[0098] Unlike Example 1, the specific components and dosages of the adhesive used in Example 2 are as follows: 50 parts 50cp vinyl silicone oil, 70 parts 500cp vinyl silicone oil, 30 parts 2wcp vinyl silicone oil, 15 parts 0.2% terminal hydrogen silicone oil, 20 parts 0.34% side hydrogen silicone oil, 3 parts MQ resin, 0.5 parts nano-sized fumed silica, 0.3 parts 5000ppm platinum catalyst, and 0.08 parts alkynol inhibitor.
[0099] Example 3
[0100] Unlike Example 1, the adhesive used in Example 3 has the following specific components and dosages: 20 parts 50cp vinyl silicone oil, 70 parts 500cp vinyl silicone oil, 60 parts 2wcp vinyl silicone oil, 20 parts 0.2% terminal hydrogen silicone oil, 25 parts 0.34% side hydrogen silicone oil, 4 parts MQ resin, 1 part nano-grade fumed silica, 0.5 parts 5000ppm platinum catalyst, and 0.1 parts alkynol inhibitor.
[0101] Example 4
[0102] Unlike Example 1, the adhesive used in Example 4 has the following specific components and dosages: 30 parts 50cp vinyl silicone oil, 130 parts 500cp vinyl silicone oil, 40 parts 2wcp vinyl silicone oil, 20 parts 0.2% terminal hydrogen silicone oil, 25 parts 0.34% side hydrogen silicone oil, 4 parts MQ resin, 1 part nano-sized fumed silica, 0.5 parts 5000ppm platinum catalyst, and 0.1 parts alkynol inhibitor.
[0103] Example 5
[0104] The difference from Example 1 lies only in the composition and dosage of the adhesive. Specifically, the adhesive formulation of Example 5 is as follows: 40 parts of 500cp vinyl silicone oil, 60 parts of cp vinyl silicone oil, 50 parts of 2w cp vinyl silicone oil, 25 parts of 0.2% terminal hydrogen silicone oil, 30 parts of 0.34% side hydrogen silicone oil, 5 parts of MQ resin, 1.5 parts of nano-sized fumed silica, 0.6 parts of 5000ppm platinum catalyst, and 0.12 parts of alkynol inhibitor.
[0105] Comparative Example 1
[0106] The difference from Example 1 is that the step of "mixing the activated graphene foam with hydroxyl vinyl silicone oil at a mass ratio of 1:1.5 to obtain 43 sheets of first graphene foam" is removed, and no modification treatment is performed.
[0107] Performance testing
[0108] (1) Heat transfer efficiency test
[0109] The graphene thermal conductive pads prepared in Examples 1-4 were subjected to heat transfer efficiency tests. The test standard was ASTM D 5470. The test method was as follows: a sample measuring 2.54cm*2.54cm*300μm (length*width*height) was taken, and the parameters were set as follows: heat source 80℃, pressure 20psi, and test time 25min. The test results are shown in Table 1.
[0110] Table 1
[0111] (2) Tensile strength test
[0112] Test standard: GB / T 528-2009;
[0113] Test method: The sample was prepared as a bell-shaped tensile specimen with a thickness of 0.3 mm and a width of 10 mm. The tensile test was carried out at a speed of 300 mm / min. The tensile strength along the orientation direction and perpendicular to the orientation direction was recorded. The test results are shown in Table 2.
[0114] Table 2
[0115] (3) Compression and rebound performance test
[0116] Test standard: GB / T 528-2009;
[0117] Test method: Take a sample with an indenter of the same size, compress it to 50% for 30 minutes, record the compression amount, then remove the pressure and allow it to rebound for 10 minutes, record the rebound amount. The rebound rate is calculated as: rebound amount / compression amount * 100%. The results are shown in Table 3.
[0118] Table 3
[0119] (4) Cracking resistance test under ultimate pressure;
[0120] Test method: A standard-sized graphene sample (25.4 mm in length and width, 300 μm in thickness) was placed under a universal testing machine. The sample was subjected to different compression ratios (starting from 0 and increasing by 5% each time), with each compression held for 30 minutes. The pressure was then removed, and the sample was observed for cracking. The test results for the compression ratios that resulted in cracking are shown in Table 4.
[0121] Table 4
[0122] In summary, this application improves the performance of the graphene thermal pad by performing multiple modification processes, enabling the thermal pad to make better contact with the component and effectively fill the air gap.
[0123] The above are merely preferred embodiments of this application and do not limit the patent scope of 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 patent protection scope of this application.
Claims
1. A method for preparing a graphene thermally conductive pad, characterized in that, The preparation steps include: S10, provides multiple graphene foams; S20. Remove the surface hard skin from multiple graphene foams, perform laser drilling and edge cutting, and plasma activation to obtain activated graphene foam. Then, perform a first modification treatment on the activated graphene foam with hydroxyl vinyl silicone oil to obtain multiple first graphene foams. S30. A second modification treatment is performed on multiple first graphene foams and adhesives to obtain multiple second graphene foams. S40. Multiple second graphene foams are bonded together along the thickness direction and pressed into blocks, and then cured to obtain third graphene foam. S50. The third graphene foam is cut into sheets along the thickness direction to obtain a graphene thermal pad, wherein the adhesive includes: linear low molecular weight vinyl silicone oil, linear medium molecular weight vinyl silicone oil, linear high molecular weight vinyl silicone oil, crosslinking agent, chain extender, reinforcing agent, toughening agent, catalyst and inhibitor.
2. The method for preparing the graphene thermal pad as described in claim 1, characterized in that, In step S10: The graphene foam has an average density of 0.15-0.25 g / cm³. 3 ; and / or, The thermal diffusivity of the graphene foam is ≥600 mm. 2 / s; and / or, The thickness of the graphene foam is 200-300 μm.
3. The method for preparing the graphene thermal pad as described in claim 1, characterized in that, In step S20: The step of removing the surface hard skin includes: breaking up and adhering the surface hard skin to remove it; and / or, After the laser drilling and edge trimming step, the average hole diameter is 10–200 μm, and the distance between the holes is 100–4000 μm; and / or, The plasma activation treatment step includes: processing with a direct-injection plasma activation treatment device; and / or, The first modification treatment step includes: coating the activated graphene foam with xylene-diluted hydroxyvinyl silicone oil, and after complete absorption, vacuum heating treatment is performed to obtain multiple first graphene foams. The coating is: 3 to 9 mg of hydroxyvinyl silicone oil is sprayed onto each square centimeter of the activated graphene foam.
4. The method for preparing the graphene thermal pad as described in claim 1, characterized in that, In step S30, the second modification process includes: spraying the adhesive onto the plurality of first graphene foams and mixing them to obtain a plurality of second graphene foams, wherein the spraying is: 70 to 110 mg of adhesive is sprayed onto each square centimeter of first graphene foam.
5. The method for preparing the graphene thermal pad as described in claim 4, characterized in that, The linear low molecular weight vinyl silicone oil is 50 cp vinyl silicone oil, the linear medium molecular weight vinyl silicone oil is 500 cp vinyl silicone oil, and the linear high molecular weight vinyl silicone oil is 2 w cp vinyl silicone oil. The mass ratio of the 50cp vinyl silicone oil, the 500cp vinyl silicone oil, the 2wcp vinyl silicone oil, the chain extender, the crosslinking agent, the reinforcing agent, the toughening agent, the catalyst, and the inhibitor is (20-50):(60-130):(30-50):(15-25):(20-30): (3–5): (0.5–1.5): (0.3–0.6): (0.08–0.12); and / or, The mass ratio of the first graphene foam to the adhesive is 1:(1-3).
6. The method for preparing the graphene thermal pad as described in claim 5, characterized in that, In the adhesive: The linear low molecular weight vinyl silicone oil includes low molecular weight silicone oils with a viscosity below 500 cp; and / or, The linear medium molecular weight vinyl silicone oil includes medium molecular weight silicone oils with a viscosity of 500 cp to 5000 cp; and / or, The linear high molecular weight vinyl silicone oil includes high molecular weight silicone oils with a viscosity of 5000 cp or higher; and / or The crosslinking agent includes hydrosilicone oil; and / or, The chain extender includes hydrogen-terminated silicone oil; and / or, The reinforcing agent includes MQ resin; and / or, The toughening agent includes nano-sized fumed silica; and / or... The catalyst includes a platinum catalyst; and / or, The inhibitors include ethynol inhibitors.
7. The method for preparing the graphene thermal pad according to any one of claims 5 to 6, characterized in that, The preparation steps of the adhesive include: mixing the linear low molecular weight vinyl silicone oil, the linear medium molecular weight vinyl silicone oil, the linear high molecular weight vinyl silicone oil, the crosslinking agent, the chain extender, the catalyst, the inhibitor, the reinforcing agent and the toughening agent.
8. The method for preparing the graphene thermal pad as described in claim 1, characterized in that, In step S40, the thickness of the third graphene foam is 40-50 mm; and / or, In step S50, the thickness of the graphene thermal pad is 0.3 to 2.0 mm.
9. A graphene thermally conductive pad, characterized in that, The graphene thermal pad includes a graphene thermal pad prepared by the method described in any one of claims 1 to 8.