Highly accelerated life testing (HALT) for multilayer ceramic capacitor qualification

A highly accelerated life-test (HALT) method was employed to life test nearly 20 vendor lots of 50-V rated COG, X7R, and Z5U chip capacitors at 400 V and 140 degrees C stress. Their failure rates were compared with those observed in the standard 1000-h life test at 100 V and 125 degrees C stress. Acceptable correlation was observed between the two methods. In addition to reducing the qualification time from months to a few days, HALT has the capability of ascribing the device failures to manufacturing-process or material defects. It can greatly help users to identify defective lots quickly, determine the mean-time-to-failure of each incoming, lot, and detect major changes in the vendor's processes.<
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