Electrochemical Migration of ENIG surface finish in Na 2 SO 4 Environment

The electrochemical migration (ECM) behavior of Electroless Nickel Immersion Gold (ENIG) surface finish was studied using Na 2 SO 4 solutions with various concentrations. The investigations were carried out by water drop (WD) test. During WD test the electrochemical processes were followed by electrical and visual inspections. Based on the mean-time-to-failure (MTTF) data it was shown that MTTF increased at 0.1 mM Na 2 SO 4 solution, then on higher concentrations MTTF significantly decreased and stabilized over the concentrations.