Development on Fatigue Life Model of Lead-Free Solder for First Failure Prediction

Abstract

First failure (FF) fatigue life model of lead-free solder is not available from literature, especially for package used in mobile application. In this study, fatigue life model for FF prediction under temperature cycling test has been developed for low-Ag content solder joint used in board level assembly through reliability test and finite element analysis and simulation. The developed life model is validated and has a good accuracy with +/-20% error between prediction and physical testing data. Volume selection is discussed for better understanding the failure mode and site. Relationship between FF and characteristic life is also studied.