Thermal cycling aging effects on the tensile property and constitute behavior of Sn–3.0Ag–0.5Cu solder alloy

Thermal cycling aging effects on the tensile property of Sn–3.0Ag–0.5Cu solder alloy are investigated experimentally and theoretically. Solder specimens were tested at temperature ranges from 77 to 293 K and 77–398 K with different cyclic numbers. Thermal cycling optimizes the microstructure of solder and causes dislocation, which can enhance both tensile strength and plasticity of solder material. It is observed experimentally that the plasticity of Sn–3.0Ag–0.5Cu solder alloy is strongly time dependent, higher cycle number leads to an increase of plastic strain. A unified creep plasticity constitutive model is developed by modifying the drag strength and taking the effects of temperature and cycling number into account. A new material damage parameter is proposed to consider the temperature effect during the treatment, which is incorporated into the developed model to describe the mechanical behavior of Sn–3.0Ag–0.5Cu solder under thermal cycling. The numerical predictions agree well with the experimental results of Sn–3.0Ag–0.5Cu solder alloys, it shows the developed constitutive model can describe the mechanical properties of Sn–3.0Ag–0.5Cu solder under thermal cycling with reasonable accuracy.