Inverse analysis of solder joint creep properties

Experimental results from shear test on solder joints and Finite Element analysis method have been used to improve the creep constitutive equation for lead free SnAgCu solder alloy. Parameters in Anand's viscoplastic model that are most sensitive to the solder joint's stress-strain relationship have been identified and then modified in an inverse Finite Element analysis so that the new constitutive equation can be used as input data for computer simulation that predict behaviour and reliability of solder joints.