Silicon rubber is a linear polymer material. The main chain is composed of silicon oxygen bonds with strong bond energy. It has excellent light resistance, aging resistance, dielectric properties, corrosion resistance, mildew resistance and excellent chemical stability. Because of these comprehensive properties, silicone rubber is widely used in "thermal interface materials". However, the thermal conductivity of pure silicone rubber products is low, and its thermal conductivity is about 0.168W/(m• K), which is difficult to meet the needs of users when it is directly applied to "thermal interface materials". In order to improve its thermal conductivity and broaden its application in the field of electronics, the most commonly used method is to disperse the filler with high thermal conductivity into the silicone rubber matrix to form sufficient heat conduction chain similar to the network structure, so as to improve the thermal conductivity of the silicone rubber based "thermal interface material". This issue of Baiyun online, lead you to know several commonly used silicone rubber based "thermal interface materials".

1. "Thermal conductivity interface material" based on hydrocarbon silicone oil

With hydroxyl silicone oil as the substrate "thermal interface materials commonly used thermal conductive silicone or silicone paste products, its with dimethyl silicone oil, methyl phenyl silicone oil or long chain alkyl silicone oil, such as hydroxyl silicone oil as base oil, through mechanical mixing thermal conductivity of compound or metal powder (such as aluminum oxide, zinc oxide, boron nitride, aluminum powder, copper powder or silver powder, etc.) made from as thickening agent products. This kind of product has good shape at any time, no flow, high thermal conductivity, no solidification, no corrosion of interface materials and other characteristics, is widely used in electronic equipment, electrical equipment, communication equipment, power modules and other fields, to solve the heat conduction and heat dissipation between electronic components and heat dissipation plate or heat dissipation plate. Its main product performance index has thermal conductivity, oil degree, taper degree and so on.

2, with hydroxyl silicone oil as matrix condensation type "thermal interface material"

Hydroxyl silicone oil for matrix condensation type "thermal interface materials" normally with alpha, omega - dihydroxy polydimethylsiloxane based polymer, under the condition of high temperature vacuum mixing high thermal conductivity filler masterbatch was prepared, complete, and the crosslinking agent, catalyst and other characteristics of additives on the moisture of scattered high speed mixer mixing. The discharging products are usually packaged in sealed tubes or flexible tubes, and the packaged products are divided into single component, double component, or even multiple components. When used, the extruded product is paste, which is cured by crosslinking with water molecules and releases small molecules. Common condensation type of "thermal interface materials" thermal retardant adhesive, thermal bonding adhesive, thermal potting adhesive and other products, is widely used in solar photovoltaic, automobiles, computers, mobile phones, new energy and other electronic and electrical fields, to ensure the safe, stable and reliable operation of thermal electronic components. Its main product properties are conventional properties (such as dry surface, thin consistency, etc.), mechanical properties (such as tensile strength, elongation, etc.), electrical properties (such as volume resistivity, dielectric strength, etc.) and thermal conductivity

3, vinyl silicone oil as the base of the "thermal interface material"

Vinyl silicone oil for the base of the "thermal interface material" is composed of vinyl polysiloxane as the base polymer, thermal conductivity powder as the filler, containing hydrogen silicone oil as the crosslinking agent and other special groups of additives. Its reaction principle is in the eighth group of transition metal compounds (such as Pt, etc.) under the catalytic action of polysiloxane and si-H bond for hydrogen-silicon addition reaction, the formation of a new Si-C bond, the linear siloxane into a network structure, after the completion of the reaction, crosslinking into elastomers. In the reaction process, this kind of silicone rubber based "thermal interface material" has no by-products, very small shrinkage rate, high conversion rate, easy control of crosslinking rate, no corrosion to the contact base material and so on. According to the form of packaging, the products can be divided into two categories: single component and double component, and double component is the majority in the market. The common products are silicone thermal conductivity potting adhesive, silicone gel and other products, mainly used in automobile, consumer electronics, cable accessories and other electronic components and circuit board insulation potting, play a good sealing protection, cushioning, shock absorption, heat dissipation and other functions. Compared with the condensation type "thermal interface material" product performance, add molding generally has rubber type and gel type, the corresponding product control standards are not consistent, need to adjust the process formula according to the actual use, test performance, control the test item index.