Study on paddle delamination for quad flat no leads package

This main part of this thesis is concerning with the delamination phenomenon of quad flat no leads package (QFN) between epoxy molding compound (EMC) and exposure bottom paddle in IC package assembly factories. The characteristics show that the delamination phenomenon of QFN product occurred after Electro de-flash process (ED). ED process is making use of the redox reaction to produce hydrogen (H2) from hydrogen ions and electron (e-) to strip the flash on lead frame during EMC molding process by moving to permeate and impact, and then the delamination phenomenon occurred. The purpose of this thesis is that ED process is replaced by no Electro De-flash method, Chemical De-flash process to keep the de-flash ability and prevent from the delamination phenomenon between EMC and exposure bottom paddle is occurred. The results were proved that the delamination issue is found after ED process and never found after CD process. And CD process is better than ED process for the delamination issue. That is, CD process used for de-flashing would be an important reference for improving the shortcoming of delamination in industry.