The striated deformation of Sn solders under high frequency resonant vibration

A striated deformation feature was found commonly in solders during vibration test. This deformation evidence will be promoted under resonant vibration for the Sn-rich phase with a coarse size or the specimens with a longer vibration cycles. For Sn-Pb solders, the occurrence of striated deformation tend to generate fine intergranular cracks that will promote the crack propagation and the formation of main crack. On the other hand, for lead-free Sn-Zn and Sn-Ag solders, the striated deformation virtually plays an important role in absorbing the vibration energy and leads to an improvement of the vibration fracture resistance