Thermal Heat Sink Paste Information

Features of Heat Sink Paste

Heat sink paste is made of Polysiloxane and the high thermal conductive filler, featuring non-toxic, tasteless and non-corrosive. Its chemical and physical properties are stable with excellent electrical insulation and excellent thermal conductivity. Heat sink paste like smt adhesive is resistant to high and low temperature with the temperature range of -600℃ to 250℃. After long-term working it will not be air-dried, hardening or melting. It is mainly used to fill the gap between the heating body and heat sink, improving the cooling effect.

Detailed Information on Heat Sink Paste

Heat sink paste is often called thermal grease, but actually should be named silicon paste for it is made of silicone oil. The silicone oil is a kind of polysiloxane. From a structural point of view, heat sink paste is a long chain consisting of a lot of silane with thousand to millions of molecular. They feature excellent heat resistance, electrical insulation, thermal conductivity, damping, and its viscosity is not sensitive to temperature. Their chemical property is stable, less volatile, non-toxic and tasteless. The silicon paste filler is the very fine powder through grinding with zinc oxide / alumina / boron nitride / silicon carbide / aluminum as their ingredients. Silicone oil ensures a certain amount of mobility, and fillers help fill the tiny gap between the CPU and heat sink to ensure thermal conductivity. Due to low sensitivity of silicone oil to temperature sensitivity, it won’t become thick under low temperature or become diluted under high temperature, and it features non-volatile, so available to be used for a long time. How to transfer heat between heat the heat sink and CPU? Well it mainly relies on conducting method – directly connecting the heat sink paste and CPU. The purpose of using the thermal grease is to fill the gap between them, making the connection perfect. If the grease is used in excess, there would form a grease layer between the CPU and heat sink, so the cooling path turns out to be CPU --- grease --- heat sink.

Notes When Using Heat Sink Paste
Some high-grade thermal grease uses the silver powder or aluminum powder as its filler, for these metals have high thermal conductivity. But metal particles have big sizes with poor filling effects, so the performance of heat sink paste cannot be improved greatly. Even though grease features electric conductivity, short circuit would lead if not use appropriately.

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