A reliability model for connector contacts

Connector contacts have a typical end-of-life behavior during accelerated life testing. A model that predicts the change in resistance ( Delta R) for an aging contact is developed based on that behavior. The model shows that the duration of accelerated life tests can sometimes be reduced by up to 50%, resulting in substantial time and cost savings. Analysis of the model leads to several unexpected conclusions. For example, the evaluation of contact reliability, using Delta R as a parameter, does not agree with a time-to-failure approach in which each individual contact is assumed to have a specific failure time. The agreement is restored by the use of change in conductance ( Delta G) ratios. The use of Delta G by itself leads directly to the conclusion that contact reliability evaluated at some point in a contact's life explicitly depends on the resistance of the contact when it was put into use.<
>