1. Heat conducting silicone grease heat conducting silicone grease is a widely used heat conducting medium at present. It is an ester formed after heating, decompression, grinding and other processes with silicone oil as raw material and thickener and other fillers. The material has a certain viscosity and has no sense of particle. The working temperature of thermal conductive silicone grease is generally - 50 ℃ ~ 180 ℃. It has good thermal conductivity, high temperature resistance, aging resistance and waterproof characteristics. In the heat dissipation process of the device, after heating to a certain state, the heat conductive silicone grease presents a semi fluid state, filling the gap between the CPU and the heat sink, making the connection between them closer, so as to strengthen heat conduction. Under normal circumstances, the thermal conductive silicone grease is insoluble in water and is not easy to be oxidized. It also has certain lubricity and electrical insulation. (at present, the better brands in the market include Dow Corning, Xinyue, and domestic good thermal conductive silicone grease Youtian Zhongshan (it is said to be a brand in Hong Kong) , Li Feng Electronics, Huaneng Zhiyan, among the domestic brands, I have tried the 7.0 thermal conductivity of tianzhongshan 940 and kuneng Zun. In the early stage, the temperature of kuneng Zun will be slightly better than 940 by 0.5 ℃, but the temperature in Zhongshan will be 1 ℃ higher than that of kuneng Zun two days later. I don't know if it's my method. After asking the manufacturers and peers in the industry, I come to the conclusion that kuneng Zun takes radiator as its core Live, the thermal conductive silicone grease is sub packaged by Dow Corning 5126 and Xinyue 7762, and the other part is sub packaged by tianzhongshan and Huaneng Zhiyan products as raw materials, so it is not put into domestic brands.)
2. Heat conductive silica gel (heat conductive adhesive) heat conductive silica gel adopts a molecular chain based adhesive (107 adhesive) containing c-Si results, and heat conductive powder is added to the base adhesive. Then the molecular chains are crosslinked by a crosslinking agent to form a thermal conductive adhesive that can bond materials and conduct heat. Its thermal conductivity is slightly lower than that of thermal conductive silicone grease, but it has a bonding function than thermal conductivity. It can be widely used in some electronic thermal components that need bonding. However, because its thermal conductivity is not as high as that of thermal conductive silicone grease and its thermal resistance is higher than that of silicone grease, it can not be used in fields with high thermal conductivity requirements. (at present, there are many brands of thermal conductive silica gel in the market as well as silicone grease, but what I want to say is that the thermal conductivity of thermal conductive silica gel cannot be improved due to its special properties and packaging requirements. Generally, the thermal conductivity at the domestic level is between 0.8-1.5, which is not unknown, but it is often achieved at the expense of other properties, such as viscosity Relay, shear strength. The more important thing is its surface wettability (if you don't understand the importance of surface wettability, you can baidu, or see my next article report high.) at present, there are not many brands in this area because of their application. Brands include Dow Corning, Xinyue, tensan, and sisun)
3. Graphite gasket, a kind of heat conducting medium, is relatively rare and is generally used on some objects with small heating capacity. It adopts graphite composite material, after certain chemical treatment and heat conduction, and is suitable for the heat dissipation system of electronic chips, CPUs and other products. In the early Intel boxed P4 processor, the material attached to the bottom of the radiator was a graphite thermal conductive gasket called m751 (Fig. 2). The advantage of this thermal conductive medium was that it had no viscosity and would not "pull the CPU from the base" when removing the radiator. In addition to the above common heat transfer media, aluminum foil heat transfer gasket and phase change heat transfer gasket (with protective film) also belong to heat transfer media, but these products are rare in the market.
4 soft silica gel thermal conductive pad soft silica gel thermal conductive insulating pad has good thermal conductivity and high-grade withstand voltage insulation, with thermal conductivity of 1.75w/mk and voltage breakdown resistance of more than 4000V. It is an alternative product to replace thermal conductive silicone grease. Its material itself has certain flexibility and fits well between power devices and heat dissipation aluminum fins or machine shell, so as to achieve good thermal conductivity and heat dissipation, It meets the requirements of the current electronic industry for heat-conducting materials. It is a good product to replace the binary heat dissipation system of heat-conducting silicone grease heat-conducting paste and mica sheet. This kind of products can be cut arbitrarily, which is conducive to automatic production and product maintenance. The process thickness of silica gel heat conductive insulating pad varies from 0.5mm to 5mm. It is added every 0.5mm, i.e. 0.5mm1mm1.5mm2mm to 5mm. It can be increased by 15mm for special requirements. It is specially produced for the design scheme of heat transfer through the gap. It can fill the gap and complete the heat transfer between the heating part and the heat dissipation part. At the same time, it also plays the role of shock absorption, insulation and sealing, and can meet the design requirements of miniaturization and ultra-thin of social equipment, It is a new material with processability and usability. The flame retardant and fireproof performance meets the requirements of u.l94v-0 and meets the environmental protection certification of EU SGS. The brands are: bages, Laird, Fuji glass, tensan, aochuan and born
5 phase change heat conducting materials phase change materials are mainly used for high-performance devices requiring low thermal resistance and high heat conduction efficiency, microprocessors and power devices requiring low thermal resistance to ensure good heat dissipation. Phase change heat conducting materials change at 45 ℃ - 58 ℃ and flow under pressure to fill the irregular gap between heating body and radiator and squeeze out air to form a good heat conducting interface