Brittle fracture behavior and interfacial reaction of Sn-Ag-Cu solders on ENIG and ENEPIG surface finish

摘要

Brittle fracture behavior of Sn-Ag-Cu solders on ENIG and ENEPIG surface finish were evaluated with varying the metal turn over (MTO) of the Ni(P) plating solution in this study. As the MTO increased, the shear strength of the solder joints decreased. Percentage of brittle fracture increased as the MTO of Ni(P) solution increased. The solder joints on ENIG surface finish showed higher brittle fracture rate than that on ENEPIG surface finish. From TEM observation, nano-voids were observed in the Ni-Sn-P layer and the amount of nano-voids increased as the MTO of Ni(P) plating solution increased.