Rough Nickel PPF for Mold Adhesion Improvment

This paper describes the development of a rough nickel plating process for palladium-preplated leadframe (PPF) that provides a consistent surface roughness at the nano-or submicron scale. This process enables outstanding adhesion with epoxy molding compound (EMC) even after Moisture Sensitivity Level-1 treatment, as well as good bonding and solderability performance. Fracture surface analysis indicated that the fracture mode of rough nickel PPF was cohesive failure inside EMC, while the interfacial failure occurred at traditional PPF and EMC interface. Here we demonstrate rough nickel PPF is an effective technique to enhance the mold adhesion for use in leadframe-based integrated circuit (IC) packages where high reliability is required.