Visualization of resistance distribution and microstructure in locally degraded multilayered ceramic capacitor

Abstract

This study characterizes low-resistance regions in a locally degraded multilayered ceramic capacitor (MLCC) using scanning spreading resistivity microscopy, scanning electron microscopy, and transmission electron microscopy. The MLCC consists of a core–shell structure that degrades before electrical breakdown in highly accelerated lifetime tests. Areas of local insulation degradation in the MLCC are revealed by Dy-containing solid solution grains. The characteristic grains within the low-resistance region show the resistance distribution. Degraded grains around the anode, which are assumed to strongly reflect the front-line insulation degradation, suggest that the shell and grain boundaries strongly repress insulation degradation. These results show that improved material uniformity and microstructure design are vital for achieving highly reliable MLCCs.