Analysis of dielectric degradation and resistivity distribution in BaTiO 3 MLCCs using the two-terminal method and SEM

Insulation degradation and resistivity distribution in BaTiO 3 -based multilayer ceramic capacitors with Ni internal electrodes were investigated by two-terminal current–voltage measurements and charging-contrast scanning electron microscopy (SEM). After highly accelerated life testing, the short-circuited region was identified by infrared optical-beam-induced resistance change analysis and removed. The remaining dielectric was progressively polished, and resistance was measured at each dielectric distance. In the low-electric-field region, ohmic conduction dominated, and resistivity increased from the cathode toward the anode, showing qualitative consistency with SEM observations from a separate stressed specimen. In the high-electric-field region, apparent resistivity showed little position dependence. Temperature-dependent measurements yielded apparent activation energies of 0.51 ± 0.04 eV for the fresh specimen and 0.82 ± 0.10 eV for a separately prepared stressed specimen at 1.08 kV mm −1 . The failure of simple Poole–Frenkel and space-charge-limited current models to describe the data supports transport controlled by degradation-modified grain-boundary barriers.