抄録
A probe pin to inspect the operation of semiconductor chips is damaged by repetition of inserting it to a Sn-Bi solder ball of the semiconductor package and conducting due to the low melting temperature of the Sn-Bi solder. The purpose of this study was to clarify the growth behavior of the reaction layer formed at the interface between the probe pin and the Sn-Bi solder. A Pd-30Cu-29.5Ag-0.5Zn （mass%） probe pin and a Sn-58Bi （mass%） alloy were prepared. The interfacial reaction between the probe pin and Sn-58Bi was investigated by aging at 120℃ for up to 1000 h. It was found that the PdSn3 + PdSn4 + Cu6Sn5 + Ag3Sn layer is formed at the joint interface and grows toward the solder side in the early stage in aging. Then, Ag which diffuses fast in Sn gathered at the solder side in the reaction layer and formed the aggregate layer of Ag3Sn. With the progress of aging, the PdSn2 + PdSn + Cu3Sn + Ag3Sn layer formed at the probe side in the reaction layer. Finally, the reaction layer, which consists of the aggregate layer of Ag3Sn, the PdSn3 + PdSn4 + Cu6Sn5 layer and the PdSn2 + PdSn + Cu3Sn + Ag3Sn layer from the solder side to the probe pin side, forms at the interface between the probe pin and the solder.
