Effect of Internal Electrode Materials in Multilayer Ceramic Capacitors on Electrical Properties

Abstract

The influence of internal electrode materials on electrical properties in multilayer ceramic capacitors (MLCCs) fabricated by low-temperature co-firing was discussed. The lifetime of MLCCs is considerably improved by using copper rather than nickel internal electrodes. The leakage current density for various dc electric fields (I–V characteristics) and thermally stimulated current (TSC) were measured to investigate the lifetime improvement mechanism. The I–V characteristics demonstrated that the leakage current in a high dc electric field was suppressed in the case of copper internal electrodes. The TSC spectra demonstrated that the internal electrode materials hardly influenced the quantity of polarization charge formed by the electromigration of oxygen vacancies. Therefore, we considered that the improved lifetime by using copper internal electrodes was mainly due to the suppressed leakage current in a high dc electric field, not the quantity of polarization charge formed by the electromigration of oxygen vacancies in the MLCCs.