The orientation imaging microscopy of lead-free Sn-Ag solder joints

Orientation imaging microscopy was used to identify solidification microstructures and early stages of damage evolution in tin-silver eutectic solder joints on copper and nickel substrates after aging, creep, and thermomechanical fatigue. A visco-plastic self-consistent plasticity model was able to simulate texture changes when work hardening occurred at higher strain rates, but not with lower rates, where grain boundary sliding dominated the deformation and slip occurred predominantly on one or two slip systems that could be predicted using a Schmid (Sachs) analysis.