Vibration induced fatigue reliability of BGA packages

This paper is to investigate the fatigue life of solder balls when the BGA package is subjected to vibrating loads. To be compliant with the green package requirement, solder balls made of unleaded material, Sn-Ag-Cu, is chosen. Finite element method is performed to analyze the mechanical responses of BGA package, and fatigue life of solder balls can then be predicted by substituting the calculated results into the life prediction model. Moreover, since the variability of geometric configuration and material properties of solder balls as well as the two empirical constants in the life prediction model affect the random fatigue life, this issue is also addressed and discussed in this study. Through our work, it is mainly found that the three factors mentioned above results in more dispersive fatigue life when all of them are interactively combined than those when only each of them is independently considered.