Improved Physical Understanding of Intermittent Failure in Continuous Monitoring Method

The current trends in electronics are towards high frequency signal operation, higher interconnects density and continuous reliability improvement interconnects. In order to characterize reliability, accelerated reliability tests are applied to evaluate lifetime and to determine acceptable reliability levels. Based on this fact, the definition of failure criteria is fundamental to ensure repeatability and high confidence level of test results. Accelerated tests normally use special daisy chain components to allow in-situ electrical continuity measurements. Electrical continuity is used as an indicator of second level interconnect integrity. Industrial standards, IPC for example (IPC-SM-785, 1992), recommend the use of high sampling rate event detectors and establish failure criteria. The reason is that intermittent failures can appear long time before permanent open circuits (Brizoux et al., 2002). The approach presented in this paper is meant to improve the understanding of intermittent failure and to determine the appropriate failure criterion for continuous monitoring test.