Prediction of board-level reliability of chip-scale packages under consecutive drops

Transient structural responses of a board-level chip-scale package subjected to consecutive drops are investigated in this paper using a numerical methodology based on the support excitation scheme and incorporated with the implicit time integration scheme. Evolutions of stresses, plastic strains, and plastic strain energies in the solder joints under repetitive drop impacts are examined and correlated with actual experimental observations. Effects of isotropic hardening and kinematic hardening presumed for the solder alloy are examined and compared