Silicone rubber is a linear polymer material. The main chain is composed of silicon oxygen bonds with strong bond energy. It has excellent light and aging resistance, dielectric properties, corrosion resistance, mould resistance and excellent chemical stability. Because of these comprehensive properties, silicone rubber is widely used in "thermal conductive interface materials". However, the thermal conductivity of pure silicone rubber products is low, and its thermal conductivity is about 0.168 w / (m · K), so it is difficult to meet the needs of users when directly applied to "thermal conductive 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 fillers with high thermal conductivity into the silicone rubber matrix to form a sufficient heat conduction chain similar to the network structure, so as to improve the thermal conductivity of the silicone rubber based "heat conduction interface material". This issue of Baiyun online leads you to know several commonly used silicone rubber based "thermal conductive interface materials".
1. Thermal conductive interface materials based on alkyl silicone oil
The common products of "thermal conductive interface materials" based on alkyl silicone oil are thermal conductive silicone grease or silicone paste. It takes dimethyl silicone oil, methyl phenyl silicone oil or methyl long-chain alkyl silicone oil as base oil, and mechanically mixes thermal conductive compounds or metal powder (such as aluminum oxide, zinc oxide, boron nitride, aluminum powder, etc.), Copper powder or silver powder, etc.) as thickener. This kind of products have the characteristics of good setting at any time, no flowing, high thermal conductivity, no solidification, no corrosion to interface materials, etc., and are widely used in the fields of electronic equipment, electrical equipment, communication equipment, power module, etc., to solve the heat conduction and heat dissipation problems between electronic components and heat sink or heat sink. Its main performance indicators include thermal conductivity, oil separation, cone penetration, etc.
2. Condensation type "thermal conductive interface material" based on hydroxyl silicone oil
Hydroxyl silicone oil is a kind of "thermal conductive interface material" with condensation matrix α,ω- Dihydroxy polydimethylsiloxane is used as the base polymer. The masterbatch is prepared by mixing high thermal conductivity filler under high temperature and vacuum conditions. After that, it is evenly mixed with crosslinking agent, catalyst and other additives in a high-speed dispersion mixer isolated from moisture. The discharged products are usually packaged with sealed sealing cylinder or hose, and the packaged products are divided into single component, two-component or even multi-component. When in use, the extruded product is paste like, which can be cured by cross-linking reaction with water molecules and release small molecular substances. Common condensation type "heat conduction interface materials" include heat conduction flame retardant adhesive, heat conduction adhesive, heat conduction potting adhesive and other products, which are widely used in the fields of solar photovoltaic, automobile, computer, mobile phone, new energy and other electronic and electrical appliances to ensure the safe, stable and reliable operation of heating electronic components. Its main product properties include conventional properties (such as surface dry, dilute consistency, etc.), mechanical properties (such as tensile strength, elongation, etc.), electrical properties (such as volume resistivity, dielectric strength, etc.) and thermal conductivity.

3. Thermal conductive interface materials based on vinyl silicone oil
The "thermal conductive interface material" based on vinyl silicone oil is composed of vinyl polysiloxane as basic polymer, thermal conductive powder as filler, hydrogen silicone oil as crosslinking agent and other special components as additives. The principle of the reaction is that under the catalysis of the eighth group transition metal compounds (such as Pt, etc.), the polysiloxane with multiple Si-H bonds is hydrosilylated to form a new Si-C bond, which makes the linear siloxane form a network structure. After the reaction is completed, it is crosslinked into an elastomer. In the reaction process, this kind of silicon rubber based "thermal conductive interface material" has the characteristics of no by-products, minimal shrinkage, high conversion rate, easy control of cross-linking rate and no corrosion to the contact substrate. According to the packaging form, the products can be divided into two categories: one component and two-component. Common products include silicone thermal conductive potting adhesive, silicone gel and other products, mainly used in automobile, consumer electronics, cable accessories and other electronic components and circuit board insulation encapsulation, good sealing protection, cushioning, heat dissipation and so on. Compared with the performance of condensation type "thermal conductive interface material", the addition molding generally has rubber type and gel type, and the corresponding product control standard is inconsistent. It is necessary to adjust the process formula, test the performance and control the test items according to the actual use.