Effects of test procedures and sequences on the performance of tin-plated connectors

Laboratory and field studies were initiated with the objective of defining test procedures and sequences which would be both technically sound and cost effective for the evaluation of tin-plated connector products. A related objective was to evaluate and possibly redefine the contact resistance failure criterion for such products in low end applications. The results of this work have suggested that two parallel and relatively simple test methodologies may be adequate to evaluate the reliability of tin connector interfaces. One noncorrosive method may involve vibration as the primary stress with thermal aging used in a sequential exposure. The second method should be some form of dilute, flowing mixed gas environment having NO/sub 2/ (and possibly SO/sub 2/) at concentrations equal to or less than 100 ppb. Finally, these studies have indicated that tests of this type can drive the major degradation mechanisms for tin-plated products without producing unrealistically severe degradation. For such tests, tin-plated products may actually meet or exceed current low-end failure criteria which were actually developed for precious metal products.