Rough Silver for Improved Lead-Frame Reliability

Delamination or cracks within miniaturized semiconductor devices may occur due to the weaker adhesion of the Ag-Epoxy molding compound (EMC) interface compared to the Cn-EMC interface. To enhance the reliability of Integrated Circuit (IC) packages, adhesion promotion via surface organic/inorganic modifications to the silver surface have been the subject of many studies. An alternate approach is to improve the mold adhesion by roughening the silver surface. This paper described a new electrolytic rough silver-plating process. Roughened silver deposits, controlled by adjusting plating parameters, were obtained directly without loose particles. The resultant roughness demonstrated a positive correlation to the adhesion force of Ag-EMC.