Abstract
The dielectric composition BaTiO3-Sr2Bi4Ti5O18 fired at 1000°-1050°C has excellent C-V characteristics and a high insulation resistance at 125°C. The composition 95mol% BaTiO3-5mol% Sr2Bi4Ti5O18 exhibits a 1800 relative dielectric constant, a 1.0% dissipation factor and so weak temperature dependence of capacitance that designates EIA (Electronic Industries Association)-X7R. The fracture surface of the multilayer ceramic capacitor (MLCC) using this dielectric composition and 70Ag/30Pd internal electrode shows grain boundaries between the internal electrodes, while that of this dielectric body itself does not show. Consequently the insulation resistance of the MLCC fired at air atmosphere degraded in the accelerated humidity load test. The use of Pt for the electrode at MLCC is effective to prevent the influence of Ag/Pd on the dielectric body. It is found even if electrode is formed with 70Ag⋅30Pd material, when the MLCC is fired in weak reducing atmosphere, the above influence of the metal on the dielectric body is prevented.
