Thermally conductive silicone grease and assembly thereof

Abstract

This invention relates to the field of thermal interface materials and provides a thermally conductive silicone grease and its components. The thermally conductive silicone grease of this invention comprises a base adhesive and fillers; the volume ratio of the base adhesive to the fillers is (1-6):(4-9); the base adhesive comprises dual-vinyl-terminated polydimethylsiloxane, dual-hydrogen-terminated polydimethylsiloxane, and side-hydrogen-containing silicone oil; the molar content of the side-hydrogenated silane functional groups in the base adhesive is 0.0005 mol% to 0.003 mol%; the molar ratio of vinyl to hydrogenated silane functional groups in the base adhesive is (2-1.02):1; the molar ratio of the side-hydrogenated silane functional groups to hydrogenated silane functional groups in the base adhesive is (0.02-0.5):1. This invention starts from the fundamental point of structure and performance correspondence, innovatively designs the crosslinking network structure of the base adhesive, and then achieves the preparation of highly reliable thermally conductive silicone grease through precise proportion control.

Description

Technical Field

[0001] This invention relates to the field of thermal interface materials technology, and more specifically, to a thermally conductive silicone grease and its components. Background Technology

[0002] Semiconductor technology, a pillar industry of the information industry, is facing a major bottleneck and challenge—the thermal wall. This means that high-speed and high-density micro / nanoelectronic devices generate enormous amounts of heat within a very small space. This heat accumulates in a tiny area, causing the temperature of the electronic devices to rise sharply. Under these circumstances, the reliability and speed of electronic device operation decrease, ultimately leading to the burnout of integrated circuits. Therefore, how to dissipate the generated heat in a timely manner is a crucial issue facing the development of the semiconductor electronics industry. From a microscopic perspective, at the interface formed by different materials, the roughness of the solid surface causes the area near the interface to be filled with air, making the actual contact area much smaller than the surface area of ​​the interface. Since air has poor thermal conductivity, this greatly increases the overall thermal resistance of the interface. To mitigate the impact of this adverse factor, thermal interface materials (TIMs) with high thermal conductivity are typically filled at the interface. These materials need to have a certain degree of deformability and fluidity to fill the gaps at the interface as much as possible, increasing the contact area. Common types of thermally conductive membranes (TIMs) include thermal grease, thermal gel, thermal conductive adhesive, thermal pad, and phase change material. These are all composite materials in which thermally conductive fillers, such as zinc oxide and alumina, are added to a polysiloxane-based polymer matrix or a carbon-chain hydrocarbon oil. Thermal grease, based on a polysiloxane polymer, differs from thermal gel in that it is primarily used in scenarios where the interfacial distance between the heat source and the heat sink is less than 0.2 mm. The minimum bonding line thickness (BLT, representing the minimum thickness of the interfacial layer that the TIM can achieve during use) must meet certain requirements.

[0003] With a thickness of <50μm and even lower viscosity, it is often applied using methods such as roller printing, screen printing, steel plate printing, and dispensing.

[0004] However, with the development of 5G communication technology, chip power consumption has increased significantly, chip size has grown larger, heat flux density has increased, and chip packaging methods have evolved from 2D (two-dimensional) to 2.5D or even 3D (three-dimensional), or from chips with lids to bare die chips without lids. These changes have led to increasingly higher chip temperatures and greater warpage, especially for increasingly larger bare die chips. The inherent characteristics of bare die packaging pose significant challenges to heat dissipation. First, the planarity between multiple dies in a device is inconsistent, resulting in potential thermal inhomogeneity, requiring the TIM (Tilt-Installation Membrane) to have sufficient gap filling capacity. Second, to minimize potential reliability issues, the TIM must also fully consider the stress caused by installing a heatsink. Furthermore, for specific load ranges, shock and vibration requirements must be met, and problems caused by mutual stress must be minimized, including potential impacts on TIM performance. The superposition of mechanical and thermal stresses leads to complex strain on the TIM, resulting in a deterioration of overall heat dissipation performance. Meanwhile, the thermal load on chips and packages can cause deformation due to coefficient of thermal expansion (CTE) mismatch, especially during repeated power cycling, leading to dynamic strain in the thermal interface material (TIM). Therefore, the optimal TIM selection must be able to adapt to the complex, cumulative, static, and dynamic heat dissipation requirements of chip packages to ensure long-term reliability. Traditional thermal grease products have several drawbacks in such applications. Typical problems include shape changes caused by CTE mismatch, leading to pump-out (the phenomenon where thermal material is squeezed out of the interface due to warping caused by thermal contraction between the chip and heatsink during high and low temperature cycles, resulting in voids), and dry-out (the phenomenon where the thermal interface dries and hardens due to polymer separation at high temperatures, causing polymer to flow out of the interface and creating voids). These issues render them unsuitable for use. Therefore, such applications place higher demands on the thermal performance and reliability of the TIM used.

[0005] In the prior art, patent application CN113105744 A discloses a curable thermal grease containing a silicone oil crosslinking agent. After curing, the base silicone oil molecules are no longer linear short-chain molecules but crosslink to form a network, significantly improving strength (including cohesive strength and adhesive strength). This helps address pump-out and sagging issues in aging tests of large-size, bare-die chips. It is a single-component thermal grease, not a two-component thermal gel, uniformly mixed from multiple raw material components excluding solvents. Because it is solvent-free, it has low viscosity, good thixotropy, and a small bulk density (BLT). It can be stencil printed, applied, and then thermosetting, serving as a thermal interface material between the chip and the heatsink.

[0006] However, for high-filler-load thermal interface materials with high thermal conductivity, the drawback of this curable technology is that the system is prone to excessive cross-linking during high-temperature service, resulting in a sharp increase in modulus, hardening and drying of the material, and loss of deformability. Over time, hardware relaxation, creep, and short-term dynamic deformation that may occur during use can lead to a reduction or inconsistency in the mechanical stress on the TIM. In certain environments with large vibrations and significant temperature changes, the TIM may peel off from the interface, resulting in deterioration of heat dissipation performance, changes in thermal resistance, and a risk to overall heat dissipation. Summary of the Invention

[0007] In view of this, the purpose of the present invention is to provide a thermal grease and its components. The present invention starts from the basic point of structure and performance correspondence, innovatively designs the cross-linked network structure of the base adhesive, and then achieves the preparation of a highly reliable thermal grease through precise ratio control.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] A thermally conductive silicone grease, comprising a base adhesive and fillers;

[0010] The volume ratio of the base adhesive to the filler is (1-6):(4-9);

[0011] The base adhesive includes double-vinyl-terminated polydimethylsiloxane, double-hydrogen-terminated polydimethylsiloxane, and side-hydrogen-containing silicone oil.

[0012] The molar content of the side-hydrogenated silane functional groups (side-mounted hydrogen) in the base adhesive is 0.0005 mol% to 0.003 mol%.

[0013] The molar ratio of vinyl (Vi) to hydrosilane functional group (SiH) in the base adhesive is (2-1.02):1;

[0014] The molar ratio of side-hydrosilane functional groups (side-SiH) to hydrosilane functional groups (SiH) in the base adhesive is (0.02~0.5):1.

[0015] In this invention, "side-attached hydrogen" refers to the side-hydrogenated silane functional group that is not located at either end of the molecular chain but on the side of the molecular chain.

[0016] "Molar content of side-mounted hydrogen (mol%)" refers to the number of moles of side-mounted hydrogen silane functional groups in every 100g of all base adhesives;

[0017] "Hydrosilane functional group (SiH)" is the sum of side-hydrosilane functional groups (side-SiH) and terminal-hydrosilane functional groups (terminal H);

[0018] The side-containing hydrogen silicone oil is used as a crosslinking agent, and the number of side-attached hydrogens is the number of crosslinking points.

[0019] The molar content of side-borne hydrogen in the hydrogen-containing silicone oil in the entire base adhesive is controlled at 0.0005 mol% to 0.0030 mol% to ensure that the crosslinking point density is maintained at an appropriate level. If the content is too high, it will easily cause hardening and insufficient deformation, resulting in interface separation; if the content is too low, it will cause the crosslinking network strength to be too weak, which will easily lead to overflow and reliability problems.

[0020] The Vi / SiH molar ratio should be controlled between 2 and 1.02. If the Vi / SiH molar ratio is less than 1.02, the excess SiH will be unstable, and the material will be too hard and have an excessively high modulus during high-temperature use. If the Vi / SiH molar ratio is greater than 2, a stable network structure cannot be formed, and overflow is likely to cause reliability problems.

[0021] The molar ratio of side-hydrosilane functional groups (side-SiH) to hydrosilane functional groups (SiH) in the base adhesive is (0.02~0.5):1.

[0022] The controlled SiH / SiH molar ratio is 0.02–0.5 to ensure that the Si-O chain segments between crosslinking points have appropriate lengths, thereby providing the material with good deformability. If the controlled SiH / SiH molar ratio is <0.02, the chain segments are too long and the crosslinking network is too weak, which can easily lead to overflow and reliability problems; if the controlled SiH / SiH molar ratio is >0.5, the molecular weight between crosslinking points is too short, resulting in insufficient deformability and easy interface peeling.

[0023] In this invention, the volume ratio of the base adhesive to the filler is preferably 2:8;

[0024] The dual-vinyl-terminated polydimethylsiloxane has the molecular formula Vi(CH3)2SiO-[(CH3)2SiO] n -Si(CH3)2Vi, where Vi refers to vinyl (-CH=CH2), the degree of polymerization of the double-vinyl-terminated polydimethylsiloxane is 50-1000, and the hydroxyl content is <200ppm;

[0025] The hydrogen-terminated polydimethylsiloxane has the molecular formula H(CH3)2SiO-[(CH3)2SiO] m -Si(CH3)2H, the degree of polymerization of hydrogen-terminated polydimethylsiloxane is 50-1000, and the hydroxyl content is <200ppm.

[0026] The degree of polymerization of linear divinyl-terminated and dihydrogen-terminated polydimethylsiloxanes should be controlled within the range of DP = 50–1000, with a hydroxyl content <200 ppm. This ensures that after crosslinking, long straight-chain structures are formed between the crosslinking points, providing good ductility. If DP > 1000, the molecular weight is too large, resulting in excessively high initial viscosity and making application difficult. If DP < 50, the molecular weight is too small, and the molecular chains are prone to migration during use due to insufficient crosslinking, easily overflowing and causing reliability issues. If the hydroxyl content > 200 ppm, the hydroxyl groups are unstable at high temperatures, becoming additional crosslinking points, causing hardening, insufficient deformation, and interface separation.

[0027] In this invention, the molecular formula of the side-containing hydrogen silicone oil is (CH3)3SiO-[(CH3)HSiO] y -[(CH3)2SiO] x -Si(CH3)3, wherein the number of side-hydrosilane functional groups is y = 3 to 6, and the degree of polymerization is x+y = 20 to 250;

[0028] The side-containing hydrogen-containing silicone oil is polydimethylmethylhydrosiloxane.

[0029] The amount of hydrogen adsorbed on the side of the controlled-side hydrogen-containing silicone oil, y, is between 3 and 6, ensuring that the crosslinking agent is as follows: Figure 1 The network of uniform crosslinking points shown is preferably 4. If it is >6, it is easy to cause the crosslinking points to be too concentrated after curing, resulting in an excessively high modulus and an overly hard material.

[0030] In this invention, the base adhesive also includes a catalyst and an inhibitor.

[0031] In this invention, the catalyst is a platinum catalyst;

[0032] The platinum catalyst contains 1000-5000 ppm of Pt. The platinum catalyst is preferably Speier or Karstedt. The platinum catalyst may or may not be encapsulated in microcapsules. The microcapsules are generally made of resin.

[0033] The inhibitor is one or more of 1-ethynyl-1-cyclohexanol, 3-methyl-1-butyn-3-ol, 3,5-dimethyl-1-hexyn-3-ol, 3-phenyl-1-butyn-3-ol, diallyl maleate, and propyl methacrylate, preferably 1-ethynyl-1-cyclohexanol.

[0034] In this invention, the filler is one or more of zinc oxide, aluminum powder, aluminum oxide, magnesium oxide, aluminum nitride, silver powder, copper powder, boron nitride, carbon fiber, and silicon carbide.

[0035] The filler has a volume filling rate of 40-90 vol% in the thermal grease;

[0036] The filler is preferably one or more of (1) to (3):

[0037] (1) First packing material;

[0038] The first filler is one or more of zinc oxide, aluminum oxide, aluminum nitride, boron nitride, magnesium oxide, and carbon fiber with a first particle size, wherein the first particle size has D50 < 1 μm and D97 ≤ 40 μm;

[0039] (2) Second filler; The second filler is one or more of aluminum powder, alumina, aluminum nitride, silver powder, copper powder, boron nitride, silicon carbide, and magnesium oxide with a second particle size, wherein the D50 of the second particle size is 1 to 5 μm and the D97 is ≤ 40 μm;

[0040] (3) Third filler; the third filler is one or more of aluminum powder, alumina, aluminum nitride, silver powder, copper powder, boron nitride, silicon carbide, and magnesium oxide with a third particle size, and the D50 of the third particle size is 5 to 20 μm and the D97 is ≤ 40 μm.

[0041] In this invention, the filler is preferably composed of the following components:

[0042] First packing material;

[0043] Second packing material;

[0044] Third packing material;

[0045] The mass ratio of the first packing, the second packing and the third packing is (1-3):(2-4):(4-8).

[0046] In one embodiment of the present invention, the filler is zinc oxide powder, first aluminum powder, and second aluminum powder;

[0047] The mass ratio of the zinc oxide powder, the first aluminum powder, and the second aluminum powder is 270:378:702;

[0048] The zinc oxide powder has a D50 of 0.3 μm and a D97 of 1 μm; the first aluminum powder has a D50 of 2 μm and a D97 of 5 μm; and the second aluminum powder has a D50 of 8 μm and a D97 of 20 μm.

[0049] In this invention, additives may be selectively added as appropriate, including one or more of the following: surface treatment agents, antioxidants, pigments, dispersing and wetting agents, non-reactive silicone oils, and organic solvents;

[0050] The surface treatment agent can be any conventional surface treatment agent in the art, preferably one or more of the following: long-chain alkoxysilanes with 6 to 18 carbon atoms, alkoxysilane oligomers with a molecular weight of 500 to 1500, and alkoxy-terminated silicone oils.

[0051] The amount of the surface treatment agent is 0.1 to 2 wt% of the filler. Before use, the surface treatment agent can be used to coat the filler powder with conventional methods in the art, such as dry or wet methods, or it can be added directly to the formulation.

[0052] The antioxidant can be any conventional antioxidant in the art, preferably a sterically hindered phenolic antioxidant;

[0053] The amount of the antioxidant is 0.001 wt% to 1 wt% of the thermal grease;

[0054] The pigment can be any pigment conventional in the art, preferably carbon black;

[0055] The amount of pigment used is 0.0001 wt% to 1 wt% of the thermally conductive silicone grease;

[0056] The dispersing and wetting agent can be any conventional dispersing and wetting agent in the art, preferably anionic surfactants, cationic surfactants and nonionic surfactants;

[0057] The amount of the dispersing wetting agent is 0.1% to 5 wt% of the thermally conductive silicone grease;

[0058] The non-reactive silicone oil can be any conventional non-reactive silicone oil in the art, preferably dimethyl silicone oil, methylphenyl silicone oil, long-chain alkyl silicone oil, or long-chain alkylphenyl silicone oil;

[0059] The amount of the non-reactive silicone oil used is 0.1 wt% to 10 wt% of the thermally conductive silicone grease;

[0060] The organic solvent can be any conventional organic solvent in the art, preferably a hydrocarbon solvent;

[0061] The amount of organic solvent used is 0.1wt% to 10wt% of the thermal grease.

[0062] The method for preparing thermal grease according to the present invention includes: mixing all raw materials to obtain thermal grease, wherein the mixing is preferably carried out under vacuum conditions.

[0063] The present invention also provides a component including a heat source, a heat sink, and the aforementioned thermal grease.

[0064] The thermal grease provided by this invention can be applied to the thermal interface between the heat source surface and the heat sink surface.

[0065] In this invention, the thermal grease is preferably disposed between the heat source and the heat sink; the heat source includes one or more of a chip, a chip packaging substrate, and a chip cover plate; preferably, the surface of the heat source includes one or more of a chip, a chip packaging substrate, and a chip cover plate.

[0066] Unlike traditional thermal greases, this thermal grease is particularly suitable for scenarios where the surface of the heat source (such as a chip, chip packaging substrate, chip cover plate, etc.) has high temperature and large warpage deformation, such as CPUs and GPUs using bare dies. Specifically, the warpage amplitude is 0 to 2 times the thickness of the thermal grease application, and the peak temperature of the heat source surface reaches above 40°C. The thermal grease is placed between the two interfaces along the heat dissipation path between the heat source and the heat sink. It can be applied using conventional and convenient methods, such as by roller brush, screen printing, stencil printing, or dispensing, and then bonded to the upper and lower interfaces. During its service life, the thermal grease cures and cross-links due to the heat generated by the chip itself.

[0067] This invention starts from the fundamental point of structure and performance correspondence, innovatively designs the cross-linked network structure of the base adhesive, and then achieves a highly reliable thermal grease through precise ratio control. Attached Figure Description

[0068] Figure 1 This is a schematic diagram of the reaction in which the base adhesive of the thermal grease is thermally crosslinked to form a crosslinked network structure in an embodiment of the present invention. Detailed Implementation

[0069] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0070] To further illustrate the present invention, the following embodiments are provided for detailed description. All raw materials used in the following embodiments of the present invention are commercially available products.

[0071] Example

[0072] (1) Raw material composition:

[0073] Divinyl-terminated polydimethylsiloxane: degree of polymerization 60–500;

[0074] Hydrogen-terminated polydimethylsiloxane: degree of polymerization 60–500;

[0075] Side-borne hydrogen silicone oil (polydimethylmethylhydrosiloxane): degree of polymerization 30-50, number of side-borne hydrogens 4;

[0076] Platinum catalyst: Karstedt, Pt content 3000ppm;

[0077] Inhibitor: 1-ethynyl-1-cyclohexanol;

[0078] The filler consists of three components.

[0079] Filler 1: Zinc oxide powder coated with a surface treatment agent, D50 = 0.3 μm, D97 = 1 μm;

[0080] Filler 2: Aluminum powder coated with a surface treatment agent, D50 = 2μm, D97 = 5μm;

[0081] Filler 3: Aluminum powder coated with a surface treatment agent, D50 = 8μm, D97 = 20μm;

[0082] The surface treatment agent is a long-chain alkoxysilane with 8 carbon atoms, and the amount used is 1 wt% of the filler.

[0083] (2) Preparation method:

[0084] Double-ended vinyl-terminated polydimethylsiloxane, double-ended hydrogen-terminated polydimethylsiloxane, side-containing hydrogen silicone oil, and inhibitor were added to a planetary mixer. Then, filler 1 was added, and the mixture was stirred at 30 rpm for 1 hour. Next, fillers 2 and 3 were added, and the mixture was stirred at 30 rpm for 2 hours. After adding a catalyst, the mixture was stirred under vacuum at -99 kPa for 1 hour. The resulting mixture was then ground using a three-roll mill with a 50 μm gap to obtain the thermal grease product. The reaction process of the base adhesive after heating the grease is described in [the following section is missing from the original text]. Figure 1 As shown, Figure 1 This is a schematic diagram of the crosslinking process of a base adhesive, consisting of vinyl-terminated polydimethylsiloxane, hydrogen-terminated polydimethylsiloxane, and hydrogen-containing silicone oil, under heat. Experimental materials and results are detailed in Table 1. Unless otherwise specified, all materials in Table 1 are expressed in parts by weight.

[0085] Table 1

[0086]

[0087]

[0088] (3) Reliability testing

[0089] a. Reliability testing conditions:

[0090] Temperature cycling test: -40~150℃, heating rate 15℃ / min, high and low temperature dwell time 15 minutes, 2000 cycles;

[0091] High-temperature aging test: 150℃ for 2000 hours;

[0092] High temperature and high humidity test: temperature 85℃, humidity 85%RH, 2000h;

[0093] b. Reliability testing items: thermal resistance, hardness, and application simulation.

[0094] Thermal resistance reliability test

[0095] Apply silicone grease to the thermal resistance fixture and perform thermal resistance testing according to ASTM D5470. The test conditions are a hot-side temperature of 80°C and a pressure of 40 psi. Place the fixture sample in a temperature cycling, high-temperature aging, and high-temperature and high-humidity test chamber. After the conditions are completed, evaluate the sample. If the increase in thermal resistance before and after aging is less than 10%, the reliability test is passed.

[0096] Hardness reliability test

[0097] The silicone grease was placed in a 6mm thick hardness test sample mold and cured at 125°C for 30 minutes before being removed. Hardness testing was performed according to ASTM D2240, placing the assembled sample in a temperature cycling, high-temperature aging, and high-temperature, high-humidity test chamber. After the conditions were completed, the sample was evaluated. If the Shore 00 hardness after aging was <70, the reliability test was passed.

[0098] Application simulation reliability testing

[0099] Bare Die Application Simulation Reliability Testing: The GPU bare die chip size is 55×55mm, with a flatness of 100μm, and the heatsink surface flatness is <25μm. Thermal grease was applied to an aluminum plate with a roughness Ra of 1.6 using a sieve plate, with a coating thickness of 125μm. Spring screws were used to apply pressure and tightly bond the aluminum plate to the chip surface. The assembled sample was then placed vertically in a temperature cycling, high-temperature aging, and high-temperature and high-humidity test chamber. After the conditions were completed, the sample was evaluated, and the state of the thermal grease was observed to confirm the absence of defects such as vertical flow, voids, pump-out, dry-out, powdering, and interface separation. If these defects were not observed, the reliability test was considered passed.

[0100] IGBT module application simulation reliability test: IGBT module base plate surface flatness <50μm, area >5000mm² 2 The heat sink surface flatness is <50μm. A 70μm layer of thermal grease is applied to an aluminum plate with a roughness Ra of 1.6, and the aluminum plate is assembled to the IGBT module using screws. The assembled sample is then placed vertically in a temperature cycling, high-temperature aging, and high-temperature and high-humidity test chamber. After the conditions are completed, the sample is evaluated, and the condition of the thermal grease is observed to confirm whether there are any defects such as vertical flow, voids, pump-out, dry-out, powdering, or interface separation. If so, the reliability test is passed.

[0101] (4) Application method

[0102] a. Naked Die Application

[0103] GPU bare die application: The obtained thermal grease is printed onto the heatsink surface using a stencil. Spring screws are used to apply pressure and tightly attach the heatsink to the chip surface. The GPU chip size is 55×55mm, with a flatness of 100μm and a peak power consumption of 300W. The heatsink surface flatness is <25μm. The thermal grease application thickness is 125μm. During the service life of the thermal grease, the peak surface temperature of the thermal grease reaches over 100℃, and the maximum chip surface warpage can reach 100μm.

[0104] b. IGBT module application

[0105] IGBT module application: In screen printing, the coating thickness of the thermal grease is calculated based on the thickness of the mesh area, the total area of ​​the mesh area, and the heat dissipation area. The obtained thermal grease is printed onto the IGBT module base plate area using a screen printing method, ensuring proper distribution. Spring screws are used to apply pressure, tightly bonding the base plate to the heatsink surface. At this point, the thermal grease on the interface is compressed and fully fills the gaps between the heatsink surfaces. The coating thickness of the thermal grease is 70μm. The IGBT module base plate surface flatness is <50μm, and the area is >5000mm². 2 The surface flatness of the heat sink is <50μm. During the service life of the thermal grease, the peak temperature of the IGBT module base plate reaches over 80℃, and the maximum warpage of the IGBT module base plate can reach 100μm.

[0106] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. Application of cross-linked network structure design in improving the reliability of thermal grease; The application includes controlling the molar content of side-mounted hydrogen in the side-containing hydrogen silicone oil in the base adhesive to ensure that the crosslinking point density is maintained at an appropriate level; if the content is too high, it will cause the thermal grease to harden and deform insufficiently, resulting in interface separation and reduced reliability; if the content is too low, it will cause the crosslinking network strength to be too weak, resulting in overflow and reduced reliability of the thermal grease. The thermal grease includes: Base adhesive, fillers, and surface treatment agents; The volume ratio of the base adhesive to the filler is (1~6):(4~9); The base adhesive is a double-vinyl-terminated polydimethylsiloxane, a double-hydrogen-terminated polydimethylsiloxane, a side-hydrogen-containing silicone oil, a catalyst and an inhibitor. The molar content of the side-hydrogenated silane functional groups in the base adhesive is 0.0005 mol% to 0.003 mol%; The molar ratio of vinyl groups to hydrosilane functional groups in the base adhesive is (2~1.3):1; The molar ratio of the side-hydrosilane functional group to the hydrogen silane functional group in the base adhesive is greater than 0.05 and less than or equal to 0.

5. The degree of polymerization of the dual-vinyl-terminated polydimethylsiloxane is 50~1000; The hydroxyl content of the dual-vinyl-terminated polydimethylsiloxane is <200ppm; The degree of polymerization of the hydrogen-terminated polydimethylsiloxane is 50-1000. The hydroxyl content of the hydrogen-terminated polydimethylsiloxane is <200ppm; The amount of the surface treatment agent is 0.1wt% to 2wt% of the filler. The surface treatment agent and filler are specifically described as surface coating treatment of filler powder using a surface treatment agent; The surface treatment agent is a long-chain alkoxysilane with 6 to 8 carbon atoms and / or an alkoxysilane oligomer with a molecular weight of 500 to 1500. The packing material consists of a first packing material, a second packing material, and a third packing material; The first filler is one or more of zinc oxide, aluminum oxide, aluminum nitride, boron nitride, magnesium oxide, and carbon fiber with a first particle size; The first particle size has a D50 < 1 μm; the first particle size has a D97 ≤ 40 μm; The second filler is one or more of the following: aluminum powder, alumina, aluminum nitride, silver powder, copper powder, boron nitride, silicon carbide, and magnesium oxide, with a second particle size. The second particle size has a D50 of 1~5μm; the second particle size has a D97 ≤ 40μm; The third filler is one or more of aluminum powder, alumina, aluminum nitride, silver powder, copper powder, boron nitride, silicon carbide, and magnesium oxide with a third particle size; The third particle size has a D50 of 5~20μm; the third particle size has a D97 ≤40μm; The mass ratio of the first packing, the second packing and the third packing is (1~3):(2~4):(4~8).

2. The application according to claim 1, characterized in that, The molecular formula of the hydrogen-containing silicone oil is (CH3)3SiO-[(CH3)HSiO]. y -[(CH3)2SiO] x -Si(CH3)3, where y=3~6, x+y=20~250.

3. The application according to claim 1, characterized in that, The side-containing hydrogen-containing silicone oil is polydimethylmethylhydrosiloxane.

4. The application according to claim 1, characterized in that, The catalyst is a platinum catalyst.

5. The application according to claim 1, characterized in that, The inhibitor is one or more of 1-ethynyl-1-cyclohexanol, 3-methyl-1-butyn-3-ol, 3,5-dimethyl-1-hexyn-3-ol, 3-phenyl-1-butyn-3-ol, diallyl maleate, and propyl methacrylate.

6. The application according to claim 1, characterized in that, The filler is one or more of zinc oxide, aluminum powder, aluminum oxide, magnesium oxide, aluminum nitride, silver powder, copper powder, boron nitride, carbon fiber, and silicon carbide.

7. The application according to claim 1, characterized in that, The thermal grease also includes one or more of the following: antioxidants, pigments, dispersants and wetting agents, non-reactive silicone oils, and organic solvents.

8. A component, characterized in that, Includes heat sources, heat sinks, and thermal grease used in any of the applications described in claims 1-7.

9. The component according to claim 8, characterized in that, The heat source includes one or more of the following: a chip, a chip packaging substrate, and a chip cover plate; The warping amplitude of the surface of the heat source is 0 to 2 times the thickness of the silicone grease coating; The temperature of the side surface of the heat source reaches above 40°C.

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