Analysis on Frequency-Sensitive Failure Mechanism of Multi-Layer Ceramic Capacitor

The multi-layer ceramic capacitor fails abnormally at a certain discharge cycle. This study explores the frequency-sensitive failure mechanism. The test circuit whose discharge cycle was adjustable was built and four different kinds of multi-layer ceramic capacitors were tested. The failure phenomenon and the failure samples were analyzed. The failure fault tree was established. And the piezoelectric coefficient of the ceramic dielectric was tested. The analysis results show that the frequency-sensitive failure of the multi-layer ceramic capacitor is not caused by the circuit resonance, but by the piezoelectric effect. Because of the piezoelectric effect, the multi-layer ceramic capacitor in the AC electric field keeps the vibration consistent with the discharge frequency in the whole discharge process. When the discharge frequency is the same as the natural resonance frequency of the capacitor, the resonance is excited and the internal mechanical stress becomes very large, which makes the dielectric crack and leads to breakdown failure.