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CN-116178965-B - Heat conduction silicone grease and assembly thereof

CN116178965BCN 116178965 BCN116178965 BCN 116178965BCN-116178965-B

Abstract

The invention relates to the field of thermal interface materials, and provides a heat-conducting silicone grease and a component thereof. The heat-conducting silicone grease comprises a base adhesive and a filler, wherein the volume ratio of the base adhesive to the filler is (1-6): 4-9), the base adhesive comprises double-end vinyl end-capped polydimethylsiloxane, double-end hydrogen end-capped polydimethylsiloxane and side hydrogen-containing silicone oil, the molar content of side hydrosilane functional groups in the base adhesive is 0.0005-0.003 mol%, the molar ratio of vinyl groups to hydrosilane functional groups in the base adhesive is (2-1.02): 1, and the molar ratio of side hydrosilane functional groups to hydrosilane functional groups in the base adhesive is (0.02-0.5): 1. The invention starts from the basic point of corresponding structure and performance, creatively designs the base adhesive crosslinked network structure, and then realizes the preparation of the heat-conducting silicone grease with high reliability through accurate proportioning regulation.

Inventors

  • HAN YANG
  • ZHOU ZHANYU
  • HUANG YANAN
  • CHEN XIAONAN
  • TANG YUNHUI

Assignees

  • 北京中石伟业科技无锡有限公司
  • 北京中石伟业科技股份有限公司

Dates

Publication Date
20260505
Application Date
20230129

Claims (9)

  1. 1. The application of the base adhesive crosslinked network structure in improving the reliability of the heat-conducting silicone grease is designed; The application comprises controlling the molar content of the side-hung hydrogen-containing silicone oil in the base adhesive so as to ensure that the density of the crosslinking point is maintained at a proper level, wherein the too high content can cause hardening and insufficient deformation, and the reliability of the heat conduction silicone grease separated from the interface is reduced; The heat-conducting silicone grease comprises: Base gum, filler, and surface treatment agent; the volume ratio of the base adhesive to the filler is (1-6) (4-9); the base adhesive is double-end vinyl end-capped polydimethylsiloxane, double-end hydrogen end-capped polydimethylsiloxane, side hydrogen silicone oil, a catalyst and an inhibitor; the molar content of the side hydrosilane functional groups in the base adhesive is 0.0005-0.003 mol%; the molar ratio of the vinyl group to the hydrosilane functional group in the base adhesive is (2-1.3): 1; The molar ratio of the side hydrosilane functional groups to the hydrosilane functional groups in the base gum is greater than 0.05 and less than or equal to 0.5; The polymerization degree of the double-end vinyl-terminated polydimethylsiloxane is 50-1000; the hydroxyl content of the double-ended vinyl-terminated polydimethylsiloxane is <200ppm; The polymerization degree of the double-end hydrogen-terminated polydimethylsiloxane is 50-1000; the double-ended hydrogen-terminated polydimethylsiloxane has a hydroxyl content of <200ppm; The dosage of the surface treating agent is 0.1-2 wt% of the filler; the surface treatment agent and the filler specifically adopt the surface treatment agent to carry out surface coating treatment on filler powder; The surface treating agent is long-chain alkoxy silane with 6-8 carbon atoms and/or alkoxy silane oligomer with molecular weight of 500-1500; the filler consists of a first filler, a second filler and a third filler; The first filler is one or more of zinc oxide, aluminum nitride, boron nitride, magnesium oxide and carbon fiber with a first particle size; the D50 of the first particle size is less than 1 mu m, and the D97 of the first particle size is less than or equal to 40 mu m; The second filler is one or more of aluminum powder, aluminum oxide, aluminum nitride, silver powder, copper powder, boron nitride, silicon carbide and magnesium oxide with a second particle size; The D50 of the second particle size is 1-5 mu m, and the D97 of the second particle size is less than or equal to 40 mu m; The third filler is one or more of aluminum powder, aluminum oxide, aluminum nitride, silver powder, copper powder, boron nitride, silicon carbide and magnesium oxide with a third particle size; the D50 of the third particle size is 5-20 mu m, and the D97 of the third particle size is less than or equal to 40 mu m; the mass ratio of the first filler to the second filler to the third filler is (1-3): 2-4): 4-8.
  2. 2. The use according to claim 1, wherein the side hydrogen containing silicone oil has a molecular formula (CH 3 ) 3 SiO-[(CH 3 )HSiO] y -[(CH 3 ) 2 SiO] x -Si(CH 3 ) 3 ,, wherein y = 3-6 and x + y = 20-250.
  3. 3. Use according to claim 1, characterized in that the side hydrogen-containing silicone oil is a polydimethyl methyl hydrogen siloxane.
  4. 4. Use according to claim 1, wherein the catalyst is a platinum catalyst.
  5. 5. The use according to claim 1, wherein 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, propyl methacrylate.
  6. 6. The use according to claim 1, wherein 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, silicon carbide.
  7. 7. The use according to claim 1, wherein the thermally conductive silicone grease further comprises one or more of antioxidants, pigments, dispersing wetting agents, non-reactive silicone oils and organic solvents.
  8. 8. An assembly comprising a heat source, a heat sink and a thermally conductive silicone grease for use in any of claims 1-7.
  9. 9. The assembly of claim 8, wherein the heat source comprises one or more of a chip, a chip package substrate, a chip cover plate; The warping amplitude of the surface of the heat source is 0-2 times of the thickness of the silicone grease coating; the temperature of the side surface of the heat source reaches 40 ℃ or higher.

Description

Heat conduction silicone grease and assembly thereof Technical Field The invention relates to the technical field of thermal interface materials, in particular to a heat-conducting silicone grease and a component thereof. Background As a supporting industry for the information industry, semiconductor technology is facing a significant bottleneck and challenge, hot wall (THERMAL WALL). That is, the micro/nano electronic device, which is high-speed and high-density, generates a large amount of heat in a small space. This heat builds up in a very small range, causing the temperature of the electronic device to rise dramatically. In this case, the reliability and speed of operation of the electronic device are reduced, and eventually the integrated circuit is burned out. Therefore, how to dissipate the generated heat in time is an important issue for the development of the semiconductor electronic industry. At the interface formed by the different materials, the roughness of the solid surface can cause the vicinity of the interface to be filled with air at microscopic level, so that the actual contact area is much smaller than the surface area of the interface. The overall thermal resistance of the interface is greatly increased due to the poor thermal conductivity of air. To reduce the impact of this adverse factor, one typically fills the interface with a thermal interface material (THERMAL INTERFACE MATERIALS, TIM) having a relatively high thermal conductivity. Such materials are required to have a certain deformability and flowability so as to fill gaps at the interface as much as possible, increasing the contact area. The more common TIM comprises heat conduction grease (THERMAL GREASE), heat conduction gel (THERMAL GEL), heat conduction adhesive (thermal conductive adhesive), heat conduction gasket (THERMAL PAD), phase change material (PHASE CHANGE MATERIAL) and the like, wherein the heat conduction grease, the heat conduction adhesive (THERMAL GEL), the heat conduction gasket (THERMAL PAD) and the phase change material (PHASE CHANGE MATERIAL) are all composite materials prepared by adding heat conduction fillers such as zinc oxide, aluminum oxide and the like into polysiloxane polymer base materials or carbon chain hydrocarbon oil. The difference between the heat-conducting silicone grease and the heat-conducting gel using polysiloxane polymer as the base material is that the heat-conducting silicone grease is mostly used for achieving the minimum BLT (Bonding LINE THICKNESS, which represents the minimum Bonding thickness, i.e. the minimum thickness possible for the interface layer formed by TIM in use) under the scene that the interface distance between the heat source and the heat sink is less than 0.2mm And the viscosity is lower and is usually applied by roller printing, screen printing, steel plate printing, dispensing and the like. However, with the development of the 5G communication technology, the current power consumption of the chip is greatly increased, the size is increased, the heat flux density is increased, and the packaging mode of the chip is also developed from 2D (two dimensions) to 2.5D or even 3D (three dimensions), or from a chip with lid to a bare die without lid. The above changes result in higher and higher chip temperatures, and larger deformations such as warpage (warpage) of the chip, especially for bare die chips of larger and larger size. The inherent nature of the bare die packaging mode can present a significant challenge for heat dissipation. First, the flatness of the devices varies from die to die, resulting in potential thermal non-uniformities, and the TIM must have adequate gap filling capability. Second, to minimize the potential reliability problems of the package, the TIM must also adequately account for the stresses that result after the heat spreader is installed. Furthermore, for a particular load range, it is necessary to meet shock and vibration requirements and minimize problems caused by mutual stresses, including possible TIM performance effects. The mechanical stress and thermal stress overlap, resulting in complex strains on the TIM and thus degradation of overall heat dissipation performance. Meanwhile, the thermal load of the chip and the package is deformed due to mismatch of thermal expansion Coefficient (CTE), and particularly dynamic strain of the TIM is caused when power consumption cycles are repeated. Thus, the optimal TIM selection must be able to accommodate complex, stacked, static, and dynamic chip package heat dissipation requirements to ensure long term reliability. However, in the conventional heat-conducting silicone grease products, there are many pain points in such applications, typical problems include that the silicone grease overflows from the middle to the periphery in the cold-hot cycle to cause hollow pump-out (the phenomenon that the heat-conducting material is overflowed by the cold-hot shrinkage warp between the chip and the