Silicone oil compounds, otherwise known as Thermal Greases, are composed of a base oil of silicone fluid compounded with thermally conductive fillers. They are frequently used as Thermal Interface Materials between heat sinks and high heat flux electronics including CPUs, IGBTs, LEDs and other high powered components.
The thermally conductive fillers can be either electrically conductive or electrically isolating. Therefore, it is important to properly select the Thermal Grease that matches your application's dielectric requirements.
Thermal Greases can also be diluted with solvent. The solvent is added to reduce the viscosity of the Thermal Grease when it is being applied. After the solvent evaporates, the viscosity and thermal conductivity increase providing improved thermal performance and reduced risk of pump out.
Thermal Greases can be dispensed and/or screen printed onto the component or the heat sink surface.
The overall thermal performance is a function of many variables including the flatness of the mating parts, the Thermal Grease's thermal conductivity and the resulting bondline thickness after assembly. Please see charts below for reference data.