Prediction ofBoard-level Reliability ofChip-scale Packages UnderConsecutive Drops

Transient structural responses ofaboard-level chipscalepackage subjected to consecutive dropsare investigated inthis paper using anumerical methodology based onthesupport excitation scheme andincorporated withtheimplicit timeintegration scheme. Evolutions of stresses, plastic strains, andplastic strain energies inthe solder joints under repetitive dropimpacts areexamined andcorrelated withactual experimental observations. Effects ofisotropic hardening andkinematic hardening presumed forthesolder alloy areexamined andcompared.