Using simulations based upon modified embedded atom method potentials, the diffusion behavior of the interfacial reaction in the soldering wetting process was considered and the theoretical analysis was used to explain the on the base metal at the atomic scale. The results indicated that, when the reaction reaches the balance state, the mean square displacement of the atoms motion varies linearly with the reaction time step, the diffusion speed of the solder atoms in x direction was equal with that in the y direction, and both were faster than that in the y direction. Based on the equation of Einstein, the diffusion coefficients of the solder atoms spread on x, y, z directions were 2.03 x 10-9, 2.05 x 10-9 and 5.06 x 10-10cm2/s, respectively. The diffusion coefficient in the z-direction was in good agreement with the experimental value.

Molecular Dynamics Simulation of Diffusion Behavior between the Interface of Cu/Sn. Cheng, H., Yang, J., Liu, X., Fang, H.: Transactions of the China Welding Institution, 2009, 30[5], 49-52