Cyclic stress-strain measurement tests of Sn3.5Ag0.75Cu solder joint

For an accurate measurement of the material behavior of solder joints, a test method was established to calibrate the machine stiffness. Also another new optical experimental technique to measure the deformation across a solder joint is proposed. The test method uses the dual microscope that can measure the relative deformation of two adjacent regions. The magnified view is captured by CCD cameras and the relative deformation can be measured by the pattern matching and tracing method Several cyclic tests of the Sn3.5Ag0.75Cu were carried out under force control, displacement control and monotonic creep. The Ramberg-Osgood model and a primary secondary creep model were adopted to predict the cyclic behavior during cyclic displacement loading conditions.