Study of diffusion and atomic mobilities for fcc Ag–Cd and Ag–Sn solder alloys

Diffusion in Ag-based solders is a practical topic that has attracted world-wide attention. With the available experimental data in the literature, the atomic mobilities of Ag, Cd and Sn in fcc Ag–Cd and Ag–Sn alloys are critically explored in this work. The proposed atomic mobility parameters can reproduce a great majority of experimental data, including impurity diffusion coefficients, tracer diffusion coefficients, intrinsic diffusion coefficients and interdiffusion coefficients. The evolutions of composition profiles and Kirkendall marker shifts in Ag–Cd binary diffusion couples are also computationally studied. The atomic mobilities obtained in this work are essential to guide the design of candidate Ag-based alloys.