High-reliability epoxy molding compound for surface-mounted devices

Surface-mount packages are subjected to high levels of thermal stress in mounting, which causes package cracking or lowering of the humidity resistance after mounting. These modes of deterioration are studied experimentally and theoretically by considering the stress characteristics of molding compounds at high temperatures. The study indicated that both low stress and high strength of molding compounds at high temperature are significant causes of quality deterioration in mounting. The characteristics required of molding compounds to cope with surface-mounting methods are given.<>