Characterization of the creep constitutive behavior of SnAgCu solder in flip chip joints from the indentation creep testing

In this paper, creep behavior of the lead-free SnAgCu solder alloy after reflow process was investigated by use of Nano Indenter XP technology. Based on the steady-state power law creep relationship, the creep strain rate sensitivity exponent was determined from the indentation creep testing using dimensionless analysis method. Then, combining numerical simulation with dimensional analysis, the value of C in creep constitutive equations are obtained using search method. So power law creep constitutive equations for micro-solder joint can be obtained. The creep time-creep displacement curves calculated from numerical simulation match well with those measured from indentation experiment in room temperature, the results indicating that the steady-state creep model is valid in describing the creep mechanical properties of solder joints.