Coffin-Manson Equation determination for Sn-Zn Based Lead-Free Solder Joints

The 3D FE simulation performed in this work was used to deal with the experimental measured data, and to get the Coffin-Manson equation for lifetime prediction. Low cycle fatigue tests and FE simulations were performed on Sn-8Zn-3Bi lead free solder joints, and the Sn-37Pb eutectic solder was used as reference. The Coffin-Manson equation for the Sn-8Zn-3Bi lead free solder was fitted from the experimental measured lifetime and the shear strain calculated according to the equation N_f = 0.0294(Delta_gamma)^-2.833 , where the N_f is the number of cycles to failure and Delta_gamma is the plastic shear strain