Growth Kinetics of Intermetallic Compounds at the Interface of Liquid Sn-9Zn/Cu

Abstract

The morphology and growth of the intermetallic compound (IMC) formed between liquid Sn-9Zn eutectic solder alloy and Cu at 220-260°C was investigated. Experimental results showed that γ-Cu5Zn8 was present at the Sn-9Zn/Cu interface as the reaction product. The IMC layer growth follows the parabolic-growth law, which indicates that the growth of the IMC is controlled by the diffusion mechanisms. The activation energy of γ-Cu5Zn8 layer growth for liquid Sn-9Zn reacting with Cu substrate is determined as 50.5 KJ/mol.