Creep and fatigue characterization of lead free 95.5Sn-3.8Ag-0.7Cu solder

The creep and fatigue properties of 95.5Sn-3.8Ag-0.7Cu lead free solders were investigated. Steady-state creep behavior for 95.5Sn-3.8Ag-0.7Cu bulk solder specimens were compared to reported creep test data for solder joints. Tests were carried out at four different temperatures (-40/spl deg/C, 25/spl deg/C, 75/spl deg/C and 125/spl deg/C) and a range of stress levels. The constitutive equation for the steady-state creep law is reported. Low cycle fatigue behavior for 95.5Sn-3.8Ag-0.7Cu bulk solder specimens were investigated over a range of test temperatures (-40/spl deg/C, 25/spl deg/C, 75/spl deg/C and 125/spl deg/C) and frequencies (1 Hz, 0.01 Hz, and 0.001 Hz). Frequency modified strain-based and energy-based low cycle fatigue models are proposed for solder fatigue life prediction analysis.