Novel failure modes with overmolded printed circuit board-based surface mount packages

Several failure modes observed during reliability stress testing of a new generation of printed-circuit-board-based surface mounted packages are discussed. When compared with conventional plastic quad flat pack packages these failure modes are shown to be a direct result of the introduction of new material interfaces, and thermal expansion mismatches. If the PCB-based packages are compared to conventional plastic quad flat pack packages during the early stages of package design and process development, then PCB-based packages are comparable in risk. Improvements for addressing these failure modes are presented.<<ETX>>