Unraveling the hydrogen sulfide aging mechanism on electrical-thermal-mechanical property degradation of sintered nanocopper interconnects used in power electronics packaging

During operation in environments containing hydrogen sulfide (H2S), such as in offshore and coastal environments, sintered nanoCu in power electronics is susceptible to degradation caused by corrosion. In this study, experimental and molecular dynamics (MD) simulation analyses were conducted to investigate the evolution and mechanism of H2S-induced corrosion of sintered nanoCu, and bulk Cu was used as the reference. The following results are obtained: (1) Both sintered nanoCu and bulk Cu reacted with O2 prior to reacting with H2S, forming Cu2O, Cu2S, CuO, and CuS. In addition, sintered nanoCu exhibited more severe corrosion. (2) For both sintered nanoCu and bulk Cu, H2S-induced corrosion resulted in the deterioration of electrical, thermal, and mechanical properties, and sintered nanoCu experienced a greater extent of deterioration. (3) As was ascertained through Reactive Force Field (ReaxFF) MD simulations, the penetration of H2S and O2 combined with the upward migration of Cu resulted in the formation of a corrosion film. In addition, compared to bulk Cu, the H2S and O2 penetration in the sintered nanoCu structure was observed to occur to a greater depth, accounting for the more pronounced performance degradation.