NUMERICAL STUDY OF THIN FILM OXIDE EFFECT WITH MULTIPHYSICS COUPLING ON ELECTRICAL CONTACT PARAMETERS UNDER LOW FORCE

Abstract

Electrical contacts consist of parts where the surfaces in contact can carry electrical current just in a few contact asperity points scattered over the entire apparent contact area. Contamination and oxidation are inevitable on contact surfaces, especially for small contact under low force (mN). This oxidation phenomenon is accelerating by harsh environments (high temperature and high relative humidity RH), making then a thin film oxide on the interface. According to oxide thickness, the electrical resistance will varies allowing then a contact dysfunction. A finite element model has been used to study the multiphysics of thermo electromechanical phenomena and to analyze different cases and various physical parameters. The influence of contact structure on contact resistance was analyzed and the constriction resistance was extracted from measured resistance using a sample numerical simulation.