Prediction of interfacial reaction products between metals with same lattice structure through thermodynamic modeling

• y2 and y3 was proposed to predict the interface reaction.
• Criteria y2 was raised for the case where a spinodal decomposition exists.
• By adopting y3, general case have been successfully predicted.

Interfacial reactions exert crucial effect on the performance of soldering joints. Prediction of the first phase formed at the interface between metals benefit the design of electronic packaging. Based on our previous work, a new scheme is developed in this paper, which aims at predicting phase formation of the interface reaction between metals with the same lattice structure. In the new scheme, the conventional principle considering both the thermodynamic and kinetic factors is employed. A criterion is introduced for the case where a spinodal decomposition exists in the starting solution when the local equilibrium assumption is still valid. Another new criterion involving only nucleation driving force and entropy change is proposed for the case where no spinodal decomposition occurs and the assumption of local equilibrium is no longer valid. The validity of these criteria has been confirmed when applied to predict the intermetallic compound (IMC) formed in the binary diffusion couples such as Al/Cu, Al/Pt, Al/Au, and Co/Zn.

Figure optionsDownload as PowerPoint slide