Condensation and Growth of Kirkendall Voids in Intermetallic Compounds

A model for the simulation of Kirkendall voiding in metallic materials is presented based on vacancy diffusion, elastic-plastic and rate-dependent deformation of the material. Starting with a phenomenological explanation of the Kirkendall effect we briefly discuss the consequences on the reliability of microelectronic components. Then, a constitutive model for void nucleation and growth is introduced, which can be used to predict the temporal development of voids in solder joints during thermal cycling. We present numerical studies and discuss the potential of the results for the failure analysis of joining connections.