| 摘要 |
PURPOSE:To improve characteristics of permittivity, varistor voltage, surge yield strength, etc. by preparing ceramic composition by using the respective specified quantities of component wherein a part of Sr of SrTiO3 is substituted by Ba, component composed of two kinds of different metal oxide, and component wherein MgTiO3 and SiO2 are mixed and baked. CONSTITUTION:Main component is constituted by containing the following; 90.000-99.998 mol% of (Sr1-xBax)aTiO3 (0.001<=x<=0.300, 0.950<=a<1.000), 0.001-5.000 mol% of at least one or more kinds out of Nb2O5, Ta2O5, WO3, etc. and 0.001-5.000 mol% of at least one or more kinds out of Al2O3, Sb2O3, BaO, etc. Admixture is made by baking, at 1200 deg.C or higher, mixture composed of 60.000-32.500 mol% of MgTiO3 and 40.000-67.5 mol% of SiO2. Ceramic composition is prepared by using 100 wt.% of the main component and 0.001-10.000 wt.% of the admixture. Thereby varistor voltage is lowered; stability of characteristics is increased because the uniformity of grain diameter is improved; especially surge yield strength is improved. |
