Interfacial Reaction Characteristics of a Bi-20Sb-10Cu-0.3Ni Pb-free Solder Alloy on Cu Pad

Interfacial reaction characteristics of a Bi-10Cu-20Sb-0.3Ni Pb-free alloy on Cu pad was investigated by reflow soldering at . The thickness of interfacial reaction layers with respect to the soldering time was also measured. After the reflow soldering, it was observed that a , a intermetallic layer, and a haze layer, which is consisted of Bi and phases, were successively formed at the Bi-10Cu-20Sb-0.3Ni/Cu interface. The total thickness of the reaction layers was found to be linearly increased with increasing of the reflow soldering time up to 120 s. As the added Ni element did not participate in the formation of the thickest interfacial layer, suppression of the interfacial growth was not observed.