By Dr. Michael Osterman
Solder interconnects, which provide both electrical and mechanical connections between package electrical devices and printed wiring boards, represent a reliability concern for electronic products. The ability to predict the life time of electronics products is important for warrant and logistics purposes. In use, temperature cycling is a major contributor to the wear-out failure of solder joints during the life span of electronics. Currently, strain range and strain energy density based models are widely used for solder joint fatigue estimation. This presentation reviews existing LF solder fatigue models and provides model constants for strain range and strain energy based models. It will also review the reliability of 3rd Generation LF solders and propose models for a select number of the 3rd Generation LF solders.