Electrochemical corrosion and electrochemical migration characteristics of SAC-1Bi-xMn solder alloys in NaCl solution

The effects of Ag and Mn content were investigated from the electrochemical corrosion (ECC) and electrochemical migration (ECM) point of view in the case of SAC0307–1Bi-xMn and SAC305 lead-free solder alloys in NaCl solution. On the one hand, long-term results showed that lower silver content showed higher corrosion resistance. On the other hand, the microstructure and elemental composition of the dendrites formed after the ECM test were investigated by transmission electron microscopy (TEM) and energy dispersive X-ray spectrometer (EDS) which demonstrated that micro-alloying elements (i.e. Mn) also contributed to the ECM processes. The ECM model of Mn was also established.