The Effects of Current Density Variations in Power Contact Interfaces

Greenwood's approach to interaction between current carrying contact spots was used to analyze the degradation of single spots. The degradation is assumed to occur from electro-migration which causes a non-uniform increase in the effective resistivity across each contact spot. The latter results were used to evaluate the degradation of a simulated multi-spot interface to demonstrate the cascade failure mode believed to occur in power contacts. In addition, factors such as spot size, position and interaction with nearby spots were assessed in their impact on current density variation across the contact region.