Public evidence metadata · SEM-EVIDENCE-0014

Intermetallics in Solder Joints

This paper explains why intermetallic compounds in solder joints are not a simple "good" or "bad" issue. It covers the basic role of intermetallic layers, why excessive intermetallic formation can damage joint performance, and why the absence of expected interfacial intermetallics can indicate a process or material problem. The paper discusses several intermetallic systems that are important in electronics work, including Cu6Sn5, Cu3Sn, Ni3Sn4, AuSn4, and Ag3Sn. It also includes discussion of gold embrittlement, volume-fraction effects, and ternary intermetallic phases that can contribute to brittle interfacial behavior.