a mechanically conformable thermally conductive interface for use in electrically isolating and thermally connecting printed circuit boards to either beat sinks , metal chasses , or heat spreaders . the interface material utilizes silicone polymers of controlled molecular weight and a surface layer of a pressure sensitive adhesive may be employed . the silicone polymer is filled with a thermally conductive electrically insulative particulate such as alumina and / or boron nitride , with the silicone being prepared as a reaction product of a liquid organosiloxane together with a chain extender such as a hydride terminated polydimethylsiloxane material . a release film such as polyethylene may be utilized as the undersurface layer , if desired .