Interfacial reactions in Sn/Ni–7 wt.%V couple

In the early stage of the Sn/Ni–7 wt.%V reaction at 200 °C, solid state amorphization reaction occurs and an amorphous T phase layer is formed. After 48 h of reaction, a Ni3Sn4 phase layer is formed between Sn and the T phase, and the reaction path is Ni–V/T/Ni3Sn4/Sn. Periodic layers, Ni–V/T/Ni3Sn4/T/Ni3Sn4/Sn, are found in the couples after 72 h of reaction. The reliability assessment of the flip chip product using Ni–V barrier needs to be evaluated based on the results in the Sn/Ni–7 wt.%V couples.