Thermal transfer pads are used to improve the heat transfer capability between two surfaces.
Thermal transfer pads are used to aid in the transfer of heat away from a component and into a solid state relay heatsink. Components such as solid state relays or central processing unit generate heat during operation and need to be effectively cooled to prevent failure or damage.
Thermal transfer pads are installed between the solid state relay or other component and the heatsink surface. The pads are designed to cover up the entire mating area between the heatsink and the solid state relay, leaving no air gaps, voids, run-out or build-up.
The pads come in a wide array of different colours and can be die cut for use with solid state relays. They're made of thermal conductors such as aluminium, usually covered with a thin layer of dry thermal-transfer material on each side. This material will soften when exposed to the solid state relay's heat and offer some thermal expansion to fill gaps at higher temperatures.