
180 Green Electronics Manufacturing
to be linearly elastic except for eutectic solder joints. The eutectic solder is
considered viscoplastic and temperature dependent because creep may
occur even at room temperature.
In addition, it is reported that the temperature- and time-dependent inelas-
tic strain is the major factor that causes the failure of solder joints. Hence,
a nonlinear nite element model that accounts for both the temperature-
dependent plasticity and the time-dependent creep is constructed to charac-
terize the inelastic stress/strain response of the solder joint.
Analysis of the strain-stress data with both power law creep and Garofalo ...