Stud bump bond packaging with reduced process steps

Abstract

The stud bump bonding (SBB) process was evaluated for a flip chip in package application. An SBB packaging process, having a reduced number of process steps compared with the typical SBB process, was proposed. The two separate steps of curing of conductive adhesive and underfill epoxy, which for the application targeted in this study needed a total of four hours for curing plus further time for cooling, were not required. This proposed process therefore resulted in a reduced packaging time. Several issues affecting the assembly are also discussed in this paper.