Abstract
Recently, an environment problem has been treated as important. So many studies on a Pb-free material instead of a Pb/Sn alloy have been done actively in microelectronics packaging. Most of them focused on the thermal fatigue of solder joints. On the other hand, there is very little research done to understand the effect of frequency on solder joints when microelectronics devices are subjected to vibrations. In this study, the effect of frequency due to a vibration on a Pb-free IC package and Pb-Sn IC package which are used as BGA interconnecters was researched. The effects of a normal stress, a shear stress and a frequency to a fatigue life was studied. although the normal stress and the shear stress reduce a fatigue life, the shear stress is a dominant factor. The Pb IC package is more sensitive than the Pb-free IC package against a frequency in a range 15∿25Hz.
