Study on the different procedures for debleeding of plastic dip

Abstract

Inevitable wear on encapsulation molds and small variances in the leadframes cause a small amount of the molding compound or resin to leak out. The leakage results in either excess flash around the body of the plastic package or a thin transparent film on the leadframe and leads, which subsequently affect the solder-dipping that protects the leadframe from corrosion. Thus, effective debleeding procedure must be performed before the solder-dipping process. In this study, nine different flow procedures are designed. The results of the study show that the resin bleed can be more effectively removed by a debleeding procedure carried out immediately after molding rather than post-cure. The wet blasting process used for the debleeding purpose is also found not suitable as it causes side effects to the package surface and leadframe.