A third body contact model for particle contaminated electrical contacts

The presence of third body contamination can hinder the effectiveness of electrical contacts. Examples of such contaminations are dust particles, wear debris and so on. These particles can penetrate the contact regions and affect the contact mechanics. Once the particles engage in contact, they reduce the conductive real area of contact i.e. contact conduction. This work presents a third body contact model for the contact of two rough surface contaminated with particles. Particles are assumed to be in different sizes defined by a distribution function. A statistical approach has been adopted to model the contact of surface asperities and particles. The model is used to study the effect of sand particle contamination on the conduction of gold surfaces in cellphone connectors. The overall effect of particles is an increase in the contact force at a constant surface separation, which translates into a decrease in the conductive area of contact at a constant contact force.