Electrical Conduction Mechanisms of Barium-Titanate-Based Thick-Film Capacitors

Electrical characteristics, including degradation, of high K (
\cong
500) barium-titanate-based thick-film capacitors were studied. The leakage current of thick-film capacitors made from Ag/Pd thick-film conducting paste and high K dielectric has shown ohmic and super-ohmic (3/2 power voltage dependence) type behavior. Voltage independence of thermal activation energy and time dependence of leakage current were also observed. A healing effect by reversal of bias polarity and the effect of humidity on leakage current have also been studied. Models for leakage currents that increase with time are presented.