The Study of the Hot Bar for Reflow Process in Interconnection of Head Stack Assembly

Abstract

The interconnection bonding process of hard disk drive, soldering process is normally used. However this process still found the defects and electrical short circuit, leads to parts rejection. The major problem caused parts rejection that is incomplete in soldering process. The aim of this study is to study and optimize the hot bar, improvement of heat transfer, using finite element method to control the hottest area and uniformity of the heat distribution at the hot bar on the reflow area. The reflow interconnection is a connection between the head gimbal assembly and the actuator arm in hard disk drive. The results from visual inspection, peel test and electrical test revealed that defects has been reduced from 1.2% to 0.3%. In conclusion, the optimization of the hottest area for the hot bar in reflow process must be done