Teflon mould-releasing film used by encapsulating semiconductor chip

摘要

In a method of resin-encapsulating a semiconductor chip using a polytetrafluoroethylene film as the mold-releasing film, a polytetrafluoroethylene film F wherein the thermal shrinkage percentages thereof in both the longitudinal direction and the width direction are 5% or lower, the difference of the thermal shrinkage percentages is within 3%, and the ratio of the elastic modulus of the longitudinal direction to the elastic modulus of the width direction is from 0.5 to 2.0 during resin encapsulating is used. By using the mold-releasing film, resin encapsulating can be carried out with an excellent yield while preventing the occurrence of resin covering of the terminals or the top surfaces of the post electrodes.