摘要 |
<p>A superior thermal transfer film adhesive comprises the following composition: (a) at least one aliphatic epoxy resin; (b) a stoichiometric amount of at least one aliphatic polyamine curative; (c) an effective amount of a thixotropic agent, such as fumed silica; and (d) about 20 to 50 volume percent of at least one filler, such as alumina, based on the total of the epoxy resin and the curative. The aliphatic epoxy resin has aliphatic pendant chains of 6 to 20 carbon atoms in length. The curative comprises a long chain aliphatic or cycloaliphatic curing agent for the epoxy resin. Since aliphatic moieties, which are flexible, are used, the glass transition temperature of the resulting cured material is lower than epoxies and plasticizers employing rigid moieties. The adhesive of the invention is novel in attaining high volume resistivity (at least 10<1><4> ohm-cm at 25 DEG C), low temperature flexibility (-55 DEG C), excellent adhesion for maximum thermal transfer, and ease of reworkability.</p> |