| 摘要 |
PURPOSE:To provide a dielectric ceramic composition with small dielectric loss in a high frequency range by pressurizing and forming a powder material, for which specific small amounts of Nb2O5, MgO and TiO2 are added to a principal component of BaTiO3 and by baking the material. CONSTITUTION:After 97.55-97.90wt.% of BaTiO3, l.80-2.10wt.% of Nb2O5, 0.10-0.25wt.% of MgO and 0.15-0.30wt.% of TiO2 powder are mixed with each other and ground, 5wt.% of polyvinyl alcohol is added thereto as a binder, and the material is granulated and graded through the sift of 60 mesh, and is dried. This dried granulated material is pressurized and formed by a hydraulic press machine, and then is baked in atmosphere at a high temperature of 1400 deg.C. An Ag paste is applied to both surfaces of a thus provided BaTiO3 ceramic 12, which is baked at 800 deg.C to manufacture a ceramic capacitor 10 provided with electrodes 14, 16. The dielectric constant and the dielectric loss of this capacitor used under high frequency such as 1MHz, are not so different from those under low frequency such as 1kHz, and the rate-of-change in the temperature of the dielectric constant is relatively small. |
