Preparation of Nano BaTiO3-Based Ceramics for Multilayer Ceramic Capacitor Application by Chemical Coating Method

The base-metal-electrode multilayer ceramic capacitors (BME MLCCs) for future application require much thinner dielectric layers (< 1 mu m). Therefore, the grain size and uniformity of BME MLCC powders should be effectively controlled. In this paper, the nanosized BME MLCC powders were prepared by chemical coating method. The well-coated BaTiO3 particles were obtained by adjusting an appropriate pH value. Transmission electron microscopy, energy-dispersive spectroscopy, X-ray photoelectron spectrum were utilized for the study of microstructures and element analysis. The high-performance X7R dielectric ceramics were produced in reducing atmosphere by "two-step" sintering method at a low temperature of 950 degrees C. The dielectric constant at room temperature could reach similar to 2400, with low dielectric loss below 1.0% and high insulation resistivity similar to 10(12) Omega.cm. The ceramic grains were very homogenous with the average size below 150 nm.