Failure analysis mechanisms of miniaturized multilayer ceramic capacitors under normal service conditions

The authors report on failure analysis results on miniaturized multilayer ceramic capacitors (`0402´, `0603´, `0805´, and `1206´ sizes) which have been subjected to various degrees of thermal shock up to 450°C by ice-water or dry-ice quenching. The thermal shock resistance of `0402´ multilayer ceramic capacitors is found to be about 400°C and considerably better than that of the larger ones. Microstructural and layer-by-layer insulation resistance analyses have clearly identified the physical locations responsible for the electrical leakage of defective capacitors. No evidence of silver migration as a dominant failure mechanism has been observed for any of the defective capacitors under usual operating stresses. Comparisons of I-V characteristics for multilayer ceramic capacitors quenched by ice water and dry ice confirm that water plays a significant role in causing electrical failure at nominal bias. Failure mechanisms are then proposed to explain the failure of miniaturized multilayer ceramic capacitors under normal service conditions