Creep Behaviors of Sn0.7Cu0.1Co0.05Ni/Cu Soldering Joints

The creep behaviors of as-soldered and aged Sn0.7Cu0.1Co0.05Ni/Cu joints were studied in this paper. The results indicate that the creep behaviors of as-soldered Sn0.7Cu0.1Co0.05Ni/Cu joints are inferior to those of as-soldered Sn0.7Cu/Cu joints under shear stress of 15-22.5 MPa at 293 and 333 K, respectively. However, the creep behaviors of Sn0.7Cu0.1Co0.05Ni/Cu joints are superior to those of Sn0.7Cu/Cu joints after aging at 423 K for 24 h. The underlying creep mechanisms of the Sn0.7Cu and Sn0.7Cu0.1Co0.05Ni/Cu solder joints at experimental condition are suggested. Meanwhile, the microstructure analysis indicates that the superior creep properties of aged Sn0.7Cu0.1Co0.05Ni/Cu joints may mainly attribute to the coarsening resistance of interfacial intermetallic compounds during aging.