A Comparative Numerical Study of Thermo-Mechanical Behavior among Various IMC Joints under Thermal Cycling Condition

The utilization of transient liquid phase bonding has rendered numerous intermetallic compounds (IMCs) employed as die-attach joints in wide band gap power modules. However, the distinct thermo-mechanical behavior of these IMC joints under thermal cycling conditions has not been investigated. In this study, a comparative study of the thermo-mechanical behavior of six categories IMC joints: Ni3Sn4, Ag3Sn, Cu6Sn5, Cu3Sn, Ag9In4, and Ag3In under thermal cycling conditions were studied through finite element modelling analysis. The thermal stress that induced in IMC joint, and thermal stress/accumulated plastic strain in SiC/direct bonding copper (DBC) were specifically investigated. The results revealed a clear hierarchy among these IMCs concerning their suitability for die attachment when considering thermal cycling conditions. Notably, the Ag3Sn joint emerged as the most promising choice due to the lowest induced thermal stress within the IMC layer and less damage on SiC/DBC. Conversely, Ni3Sn4 exhibits the least favorable thermos-mechanical behavior among the IMCs.