Fatigue life prolongation effect of low frequency on 40Pb-60Sn solder

The lifetime of 40Pb-60Sn solder joints is generally dominated by creep deformation, because of slow strain rate in field uses. To explain this behavior, a torsional fatigue cycle test was carried out under isothermal conditions. A lower strain range for the creep deformation prolonged the life because the lattice vibration energy seemed to restore the defects during reciprocal cycle motion. The estimation of life from creep deformation is shown to be a more accurate approach for estimating field life.<>