Auxiliary material
Thermal Interface Pad / Grease
✓ Expert reviewed All content on this page has been reviewed by a senior motor engineer.
Process flow
Upstream manufacturing of this bought-in item is not covered yet; see the incoming inspection and approval tests.
Incoming inspection & approval tests
- Thermal conductivity / thermal impedanceASTM D5470
- Dielectric breakdown (pads)ASTM D149
- Hardness and compression setASTM D2240 / ASTM D395
- FlammabilityUL 94 V-0
Buyer FAQ
- Thermal pad or thermal grease?
- Grease gives the lowest thermal resistance on flat, rigid surfaces but can pump out over time. Pads are cleaner to assemble, fill gaps and add electrical insulation, at higher thermal resistance.
- Is thermal conductivity the right number to compare?
- No. Compare thermal resistance at your actual thickness and clamping pressure — a thinner, lower-conductivity pad can beat a thick high-conductivity one.
- What about electrical insulation?
- If MOSFET tabs are at drain potential, use an insulating pad with a stated breakdown voltage and check that burrs on the heatsink cannot puncture it.