Novel method to reduce the delamination between epoxy molding compound and lead frame silver surface

Delamination between EMC (epoxy molding compound) and lead frame is the main cause of poor package reliability. Lead frame as an important material in package, its surface condition is key factor of package delamination formation. The objective of this work was to study the relationship between oxidation of lead frame silver surface and delamination of EMC and lead frame interface. Delamination between lead frame silver surface and EMC decreased significantly. In this study, a novel and simple method was developed to oxidize the silver surface of lead frame by heating lead frame in air atmosphere. C-SAM (Mode C of Scanning Acoustic Microscopy) was used to characterized delamination between lead frame silver surface and EMC, AFM (atom force magnification), SEM (scanning electron microscope), XPS (x-ray Photo-electronic Spectroscopy) were employed to characterize lead frame silver surface.