| 摘要 |
PURPOSE:To obtain a ceramic capacitor having a large effective dielectric constant by adding a grain-boundary depletion-layer forming agent to a perovskite type oxide mainly comprising strontium titanate, mixing and pressure-molding the whole, baking the molded form in a reducing atmosphere containing hydrogen, coating the surface of the baked substance with a grain-boundary diffusate containing bismuth oxide and forming an electrode through heat treatment in an oxidizing atmosphere. CONSTITUTION:A sintering accelerating additive (0.1-50wt.%), a semiconductor-change accelerating additive (0.05-2.0wt.%) and a grain-boundary depletion-layer forming agent (0.1-6.0wt.%) composed of Sr1-x-yBaxCay (Mn1/2Nb1/2)O3 are added to a perovskite type oxide mainly comprising strontium titanate, mixing-pressure molded, and baked at 1250-1500 deg.C in a reducing atmosphere containing hydrogen. The surface of the baked substance is coated with a grain-boundary diffusate containing bismuth oxide, and an electrode is formed through heat treatment at 850-1200 deg.C in an oxidizing atmosphere. Grain-boundary insulation type semiconductor ceramics 11 and a lead 13 are mounted on the electrode 12, thus acquiring a semiconductor ceramic capacitor having large grain-boundary insulating properties. |
