Critical parameters for reliable surface mounting of high pincount packages

There have been numerous studies of delamination induced failures after reflow soldering of surface mount devices. However, most of these studies have concentrated on packages with less than 100 pins with die smaller than 100 mm/sup 2/. In this paper, we examine the failure mechanism associated with larger die in plastic quad flatpacks (PQFPs) and thermally enhanced PQFPs with up to 304 pins and die area up to 212 mm/sup 2/. The degradation in performance with increased reflow soldering temperature and absorbed moisture is characterized, and techniques to improve performance in reflow soldering from both the integrated circuit and printed circuit board perspective are discussed.