Thermal paste is a dense compound used to improve the heat transfer between electronic components and their heat sinks. It helps drain away waste heat generated by electrical resistance, and ensures that the semiconductor operates at the correct temperature and is not damaged or overheated.
In a PC, thermal paste fills in the microscopic gaps on the surface of the integrated heat spreader (or IHS) over the CPU and the base plate of the cooler to create an effective bond that allows for efficient heat transfer. This ensures that the cooling mechanism is able to disperse the heat produced by the CPU into the surrounding environment, and prevents the processor from overheating and shutting down the computer.
A good thermal paste should be easy to apply and clean up, have an even consistency and a relatively long shelf life. It should be made of a base matrix and contain a thermally-conductive filler that is engineered to suit the specific application. Typical matrix materials include epoxies, silicones, urethanes and acrylates while the fillers can vary from carbon micro-particles to aluminum oxide or boron nitride.
The type of paste you choose should also depend on your skill level in terms of application. Liquid metal compounds, for example, require a steady hand and precise application and can be difficult to get right. Additionally, liquid metal is electrically conductive which can cause problems if it flows onto the motherboard’s pins or other circuits and can be very hard to remove once applied. Fortunately, traditional pastes like the Grizzly Kryonaut or MasterGel Pro v2 are relatively simple for everyone to work with and provide excellent performance once properly applied.