Suppressing the growth of Cu-Sn intermetallic compounds in Ni/Sn-Ag-Cu/Cu-Zn solder joints during thermal aging

► The Ni/solder/Cu-Zn joint shows the remarkable thermal stability during aging. ► All interfacial intermetallic compounds are suppressed in the Ni/solder/Cu-Zn. ► Voids are inhibited at the Ni/solder/Cu-Zn interfaces. ► The cross-interaction between Ni and Cu-Zn is retarded. ► The mechanisms for the suppression of intermetallic compounds are proposed.