The influence of thermal cycling test parameters on the failure rate of electrical connectors

A new acceleration model for the reliability prediction of electrical connectors has recently been published. This model enables the evaluation of failure rates gained in highly accelerated life tests (HALT) and considers thermal and vibrational loading. However, since the initial study only covered a small set of test parameters, further study of the model is required. Previous studies have sufficiently investigated the influence of the vibration test mode on the failure rate of electrical connectors. Therefore, this study now focuses on the influence of the thermal cycling test. A commonly used automotive connector is chosen and subjected to stresses in HALT covering various upper temperatures, test durations and thermal cycling frequencies. Additionally, the principles of determining the coefficient of temperature difference and the coefficient of the thermal cycling frequency are presented, since these coefficients are connector specific and required for the acceleration model. Based on the numbers of failures in test, the influence of the various thermal cycling tests is discussed, and the coefficients are calculated for the chosen connector. In conclusion a guideline to select an appropriate upper temperature and test duration in order to compare the reliability of different electrical connectors is provided.