Realistic Creep Characterization for Sn3.0Ag0.5Cu Solder Joints in Flip Chip BGA Package

Creep tests were performed using a fixture composed of a spring, a micrometer and a heating pad to apply both heat and constant compressive load and elevated temperature to the actual solder joint. A microscopic digital image correlation technique was used to measure creep strains. A full-field deformation map of the cross-sectioned solder joint was generated as different constant loads were applied under different isothermal conditions on Sn3.0Ag0.5Cu flip chip ball grid array solder joints. Nonlinear regression was used to generate constitutive properties using the Garofalo hyperbolic sine model. The obtained constitutive properties were used to perform a finite element analysis simulation to compare the model with experimental results, which showed good agreement.