A Comprehensive Guide to Thermal Conductive Silicone: A Detailed Analysis of Components and Heat Dissipation Principles

In the heat dissipation system of electronic devices, although the thermal conductive paste is just a small tube of paste, it plays a crucial role.
The composition of thermal conductive silicone grease

Thermal conductive silicone grease is mainly composed of base oil, thermal conductive fillers and other additives.
Base oil: Silicone oil is preferred, such as dimethyl silicone oil, etc. Silicone oil has good chemical stability, low volatility, and excellent fluidity. It enables the silicone grease to have good wetting properties, allowing it to better adhere to the surfaces of electronic components and heat sinks.

Heat-conducting filler: This is the key factor determining the performance of heat-conducting silicone grease. Common heat-conducting fillers include aluminum oxide, boron nitride, silver powder, etc. Aluminum oxide has a lower cost and is widely used in ordinary computers, household appliances, and other devices with less demanding heat dissipation requirements. Boron nitride has a high thermal conductivity and also possesses good electrical insulation and chemical stability. Silver powder has a very high thermal conductivity, but it is expensive and prone to oxidation. It is generally only used in overclocking scenarios or research-grade equipment that require excellent performance.
Other additives: such as silica and bentonite as thickening agents, can be used to adjust the consistency of the silicone grease, making it easier to apply and remaining in a specific position. There are also antioxidants, which can prevent the performance of the silicone grease from deteriorating and extend its service life.

The heat dissipation principle of thermal conductive silicone grease

Electronic components generate a large amount of heat during operation. Even though the surface between the chip and the heat sink appears very smooth from the macroscopic perspective, under a microscopic view, there are countless tiny uneven areas. These gaps are filled with air, which is a poor conductor of heat and seriously hinders the heat transfer. After the conductive silicone grease is evenly applied between the electronic component and the heat sink, it will, by its own fluidity, penetrate into these tiny gaps and squeeze out the air, thereby establishing an effective heat conduction channel.

For example, during the heat dissipation process of a computer CPU, the thermal conductive paste acts like a bridge, continuously transporting the heat generated by the CPU core to the CPU cooler, ensuring the stable operation of the CPU. Moreover, the thermal conductive paste also has electrical insulation properties, which can prevent short circuits and other situations from occurring, providing additional protection for the normal operation of electronic devices.