Suppressing the growth of interfacial Cu-Sn intermetallic compounds in the Sn-3.0Ag-0.5Cu-0.1Ni/Cu-15Zn solder joint during thermal aging

摘要

Evolution of interfacial phase formation in Sn-3.0Ag-0.5Cu/Cu (wt%), Sn-3.0Ag-0.5Cu-0.1Ni/Cu, Sn-3.0Ag-0.5Cu/Cu-15Zn, and Sn-3.0Ag-0.5Cu-0.1Ni/Cu- 15Zn solder joints are investigated. Doping Ni in the solder joint can suppress the growth of Cu _3Sn and alter the morphology of the interfacial intermetallic compounds (IMCs), however it shows rapid growth of (Cu,Ni) _6Sn _5 at the Sn-3.0Ag-0.5Cu-0.1Ni/Cu interface. In comparison with the Cu substrates, the Cu-Zn substrates effectively suppress the formation of Cu-Sn IMCs. Among these four solder joints, the Sn-3.0Ag-0.5Cu-0.1Ni/Cu-15Zn solder joint exhibits the thinnest IMC, and only (Cu,Ni) _6(Sn,Zn) _5 formed at the interface after aging. It is revealed that the presence of Ni acts to enhance the effect of Zn on the suppression of Cu-Sn IMCs in the SAC305-0.1Ni/Cu-15Zn solder joint. The limited formation of IMCs is related to the elemental redistribution at the joint interfaces during aging. The Sn-3.0Ag-0.5Cu-0.1Ni/Cu-15Zn joint can act as a stabilized interconnection due to the effective suppression of interfacial reaction.