DETERMINATION OF ANAND PARAMETES FOR Pb-FREE MATERIAL SnAgCu AND LIFE PREDICTION FOR A CSP STRUCTURE

A series of tensile tests for Pb-free solder material 95.7Sn3.8Ag0.5Cu have been conducted under a wide range of temperatures and constant strain rates. A procedure for the determination of Anand material parameters through data fitting is proposed to find nine constants. Three-dimensional finite element analysis has been applied to predict the fatigue life of solder joints under thermal cycling conditions. Finally the life of CSP solder joint based on Pb-free material 95.7Sn3.8Ag0.5Cu and that based on standard Pb material 62Sn36Pb2Ag are predicted and compared. It can be found that the fatigue life based on 95.7Sn3.8Ag0.5Cu is 30.93% longer than that based on 62Sn36Pb2Ag.