HARCUBA Petr Charles University in Prague

Spoluautoři HÁJEK Michal, JANEČEK Miloš

The influence of Cu content and added Ni and P on the morphology and growth kinetics of the intermetallic compound (IMC) layer formed at the interface of Sn–Cu-based solders and a Cu substrate during ageing at elevated temperatures was studied. The reaction of a Sn-Cu alloy with the substrate leads to the formation of a thin layer of Cu6Sn5 with a typical scallop morphology. Higher Cu content leads to extensive growth with increased reaction time and temperature. At long reaction times, Cu3Sn was observed at the interface between the Cu substrate and the Cu6Sn5 layer. A small nickel addition to a Sn–0.7Cu alloy significantly changes the IMC morphology, accelerates its growth kinetics and prevents the formation of the Cu3Sn layer. In addition, the influence of IMC layer on the strength and electrical properties of simulated solder joints were investigated.