Optimal oxidation control for enhancement of copper lead frame-EMC adhesion in packaging process

Abstract

This study investigates the relationship between oxide layer thickness on lead frame and degree of delamination at the interface of copper lead frame and epoxy molding compound (EMC). It was observed that there is an optimum range of oxide layer thickness within which delamination performance is best. Contrary to previous studies, this range does not only have an upper limit but a lower limit as well. Furthermore, this range varies depending on lead frame type and supplier even though these lead frames are based on the same raw material. Based on these findings the possibility of process control was explored to expose the lead frames to temperatures which will control the oxide layer thickness within the optimum range.