The Effect of Thermal Annealing on the Microstructure and Mechanical Properties of Sn-0.7Cu-xZn Solder Joint

The microstructural properties of a Pb-free solder joint significantly affect its mechanical behaviours. This paper details systematic study the effect annealing process on microstructure and shear strength Zn-added Sn-0.7Cu joint. results indicated that IMC layer’s thickness at solder/Cu interface increases with time. interfacial layer gradually thickened increasing time temperature, while morphology changed from scallop-type to layer-type after process. However, addition 1.0 wt.% 1.5 Zn in effectively altered phase Cu-Zn suppressed growth Cu3Sn during single-lap tests confirmed decreased Sn-0.7Cu. Cu6Sn5 due Zn. fractures annealed were ductile within bulk instead layer. Increased resulted increased presence phase, which hardness