LAUSR

Abstract A high-throughput technique is developed to investigate intermetallic compound (IMC) growth kinetics in Cu/Sn and Cu/SnxIn100-x bilayer systems based on combinatorial deposition of solder thin films and observation of color changes. A model for IMC growth kinetics in the Cu/Sn system is developed and found to be in close agreement with experimental data. The model considers the diffusive fluxes of Cu and Sn through the IMC layer and the reaction fluxes of Cu and Sn atoms at the Cu/IMC and IMC/Sn interfaces, respectively. It is observed that IMC growth is controlled by the rate of reaction between Cu and Sn for thin IMCs at low temperatures, while Cu diffusion along IMC grain boundaries and Sn diffusion through the IMC lattice are rate-limiting for thick IMCs at high temperatures. It is also discovered that an addition of 44% In into Sn solder leads to the fastest IMC growth in Cu/SnxIn100-x bilayer films.