Life characteristic of multilayer ceramic capacitors under pulse conditions
This paper mainly discusses the life characteristic and failure mechanism of the multilayer ceramic capacitor(MLC) under various working conditions such as charge-discharge frequency,charge voltage,charge-discharge duty radio and discharge inverse peak factor.Experiments discover that the breakdown of MLC is the result of continuous extending of partial discharge.Exothermicity and alternating internal stress are the key factors which make partial discharge channels keep on growing.The increase of charge-discharge frequency shortens the life of MLC by accelerating the heat production.The increase of charge voltage and discharge inverse peak factor make the life of MLC over 90% shorter by enhancing both heat production and internal stress of the dielectric.An effective method to increase the life of MLC is to improve the way of heat dispersion.Dipping in oil makes the MLC have a life of 300% longer than that of only exposing in air under the frequency of 136 Hz.