ABSTRACT
The purpose of the thermally conductive film adhesive is to provide a thermal path for the flat-bodied components to dissipate heat and run cooler. The conventional wisdom among epoxy formulators is that the flexible resins could be used at no greater than 10–20% of an epoxy resin blend, where rigid epoxy resins constitute the major part of that blend. The film form consisted of a glass cloth carrier coated on each side with thermally conductive adhesive. The tear strip form was a monofilament Kevlar fiber arranged in a circuitous path and coated with thermally conductive adhesive. The idea was that in order to remove a bonded flatpack from a printed wiring board, the worker located the end of the fiber and pulled on it to tear the bondline apart. Alumina-filled polysulfide adhesive worked quite well in the fabrication and application of these film or tear strip forms, except of course for the fact that it failed the outgassing test badly.
