Contact Properties of Tin Plates

The low-load, dry circuit contact properties of typical tin plates have been investigated, with emphasis on the spherical indentor/flat configuration found in many connectors. The resistance was determined as a function of applied load for a variety Of plate combinations, as well as after exposure to a moist SO2accelerated corrosion test. The results Showed, among other things, that the contact behavior is critically dependent upon the properties of both halves of the contact system and that flats plated with matte tin behave better than those plated with bright tin.