Investigation for SnAgCu/Cu and SnAgCu/Au/Ni/Cu surface mounted soldered joints stored at high temperature

Shear strength and fracture photograms of SnAgCu/Cu and SnAgCu/Au/Ni/Cu surface mounted soldered joints stored at high temperature were investigated. Results indicate that the shear strength of SnAgCu/Cu and SnAgCu/Au/Ni/Cu soldered joints decrease with high temperature storage time increasing, and the shear strength of SnAgCu/Cu soldered joint is larger than that of SnAgCu/Au/Ni/Cu soldered joint. Analysis for fracture photograms of SnAgCu/Cu and SnAgCu/Au/Ni/Cu soldered joints indicates that most of the fractures of SnAgCu/Cu and SnAgCu/Au/Ni/Cu soldered joints occurred in the metallic layer of surface mounted components' ends and minority fractures occurred in the solder/pad interface or in the solder.