| 摘要 |
PCT No. PCT/JP90/00378 Sec. 371 Date Aug. 5, 1991 Sec. 102(e) Date Aug. 5, 1991 PCT Filed Mar. 20, 1990 PCT Pub. No. WO90/11606 PCT Pub. Date Oct. 4, 1990.The present invention provides a semiconductor-type laminated ceramic capacitor with a grain boundary-insulated structure made of Sr(1-x)CaxTiO3 as a main component, comprising the functions of a conventional capacitor which absorbs low voltage noises and high frequency noises, and a varistor when high voltage noises and electrostatic charges invade, wherein simultaneous sintering of the materials of ceramic capacitor together with the materials of inner electrodes was made possible in the manufacturing process. Besides, material to be made semiconductive is added to the main component of Sr(1-x)CaxTiO3 excess in Ti, the materials of Mn-Si, which are converted to MnO2 and SiO2 in the sintering process, are also added to the main component. A grain boundary insulated, semiconductor type capacitor is manufactured easily using only a re-oxidation process by using the starting material of the above-described composition, thereby eliminating surface diffusion process of metal oxides which is used in manufacturing conventional capacitors. According to the manufacturing method of the present invention, calcination process of laminated raw sheets prevents troubles occurring in laminated ceramic capacitors with varistor function, such as breaks of electric connections in inner electrodes; de-lamination of ceramic sheet; cracks in ceramic sheet; decrease of sintering density; and non-uniformity in the texture of sintered body, thereby improving electric characteristics, i.e. capacitance, voltage non-linearity coefficient alpha and varistor voltage, and reliability of the products. The present invention provides two major advantages in the composition of materials and in the manufacturing process.
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