Geology

Wetting

Electronic packaging

Geomorphology

Engineering

Electronics

Physical chemistry

Joint (building)

Composite material

Architectural engineering

Chemistry

Metallurgy

Materials science

Lead (geology)

Alloy

Soldering

Microstructure

Science and Technology of Advanced Materials

With the development of lead-free solders in electronic packaging, Sn-Cu lead-free solder has attracted wide attention due to its excellent comprehensive performance and low cost. In this article, we present recent developments in Sn-Cu lead-free solder alloys. From the microstructure and interfacial structure, the evolution law of the internal structure of solder alloy/solder joint was analysed, and the model and theory describing the formation/growth mechanism of interfacial IMC were introduced. In addition, the effects of alloying, particle strengthening and process methods on the properties of Sn-Cu lead-free solders, including wettability, melting and mechanical properties, were described. Finally, we outline the issues that need to be resolved in the future research.

Structure and properties of Sn-Cu lead-free solders in electronics packaging