A Study on the Growth Kinetics and Mechanical Properties of IMCs in Au-In Joints

Au-In is one of the systems used in electronic packaging, including optoelectronics, TIM packaging, and low-temperature soldering. Despite its wide use, however, interfacial reactions in the temperature range of 156.6°C to 250°C remain insufficiently explored, and the mechanical properties of IMCs other than AuIn2 are rarely documented. This study examines the microstructural evolution of Au-In diffusion couples reacted between 165°C and 215°C, utilizing cold ion cross-sectioning, and evaluates IMCs' mechanical properties through indentation methods. The growth kinetics, fitted to a power law, as well as the hardness and reduced modulus of the IMCs, are reported.