Two Big questions come into our department when we are looking at Thermal interface materials. Those are “Do I need a thermal Interface?” and “What are the different Thermal Interface materials?”
Do I need a thermal material between my component and my heat sink?
Yes you do. The main reason is imperfections in the material. Though your componet and your heat sink look as though they are smooth and they mate perfectly on a microscopic level they do not. Both surfaces are rough and if mated together only a small portion of the actual component will touch the heat sink and it will create hot spots and poor heat transfer. Using a T.I.M. or Thermal Interface Material you can fill these gaps with a thermally conductive material and help with equal and efficient heat transfer from your component to the heat sink.
This image demonstrates the rough surfaces of the heatsink and the component and shows how the T.I.M. fills the gaps.
What are the different Thermal Interface Materials?
Thermal interface products are found in two product families at Digi-Key, based on the consistency of the product as sold. The fluid type, products are listed in the Thermal - Adhesives, Epoxies, Greases, Pastes family, and solid or sheet style products are listed in the Thermal - Pads, Sheets family, both of which are filed under the Fans, Thermal Management Product category.