Degradation of a single aluminum junction due to electro-migration

A set of data provided in the literature was reported to show the impact of electro-migration on aluminum junctions. These junctions were fabricated by machining aluminum foil to provide a small connection between two conducting halves. The results appeared to show high current densities cause rapid degradation due to void and crack formation. These results are thought to occur as a result of mass transport due to electro-migration. In the present paper, a degradation model is provided using electro-migration considerations and the geometry in the work mentioned above. This approach uses estimated current flow paths and their associated current density distributions. The current densities are estimated using electromagnetic theory and the junction geometry. Moreover, the estimated effects over time of current density on the local variation of conductivity are incorporated into the model using percolation theory. Consequently, the current flow, current densities and degradation model are used in conjunction to conduct a numerical analysis of the degradation of a single aluminum junction. The approach exhibits how a model with these elements provides insight into the degradation process due to electro-migration. It is seen that this approach shows reasonably good agreement between theory and experiment providing a basis for analyzing electro-migration degradation in a variety of general cases.