Isobaric cure shrinkage behaviors of epoxy molding compound in isothermal state

The warpage of plastic-encapsulated IC packages after molding is believed to be induced by thermal and cure shrinkage of epoxy molding compound (EMC). To study the warpage behaviors of EMC, the amount of cure-induced shrinkage needs to be understood. Volume shrinkage behaviors induced by cure reaction of EMC in isothermal and isobaric states were studied with a differential scanning calorimeter (DSC) and a pressure-temperature-controlled dilatometer. The results show that higher pressure induce more volume shrinkage under fixed temperature but the difference of volume shrinkage under different pressure levels doesn't obey the principle of linearity. It is observed that the amount of chemical volume shrinkage at 145°C is higher than those under three other temperatures: 160, 175, and 190°C. The chemical volume shrinkage of EMC is found to be very process dependent.