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

Abstract

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/spl deg/C by ice-water or dry-ice quenching. The thermal shock resistance of '0402' multilayer ceramic capacitors is found to be about 400/spl deg/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.<>