High frequency dielectric composition

Claim 1

A method for preparing a perovskite-type crystal dielectric ceramic to selectively obtain a formulation consisting essentially of (1-m) parts (Sr x Ca y Mn z )TiO 3 per m parts silicon-oxygen containing compound and having a relatively high dielectric constant together with a relatively low non-linear temperature coefficient, which comprises: (A) providing mixed powder composed of a material consisting essentially of (Sr x Ca y Mn z )TiO 3 , wherein x, y, and z satisfy the following relationships: 0.98<x+y+z<1.02, 0.34<y<0.4, and 0.0075<z<0.015, by combining suitable proportions of a strontium compound, a calcium compound, a titanium-oxygen containing compound of insufficient amounts of titanate compounds are selected in the previous steps, and a manganese compound to form a mixture, suitably mixing and pulverizing; (B) calcining by heating said mixed powder to a temperature of 1100° C. to 1200° C. and maintaining that temperature for at least two hours; (C) mixing the (Sr x Ca y Mn z )TiO 3 with a suitable amount of a silicon-oxygen containing compound such as CaTiSiO 5 , CaSiO 3 , or SiO 2 to obtain a formulation (1-m) parts of (Sr x Ca y Mn z )TiO 3 per m parts silicon-oxygen containing compound, wherein m is mole fraction, and such that x, y, z, and m satisfy the following relationships: 0.98<x+y+z<1.02, 0.34<y<0.4, 0.0075<Z<0.015, and 0.005<m<0.015; (D) reducing particle size; (E) forming and (F) sintering at a temperature range of 1280° C. to 1400° C. for two to eight hours.

Claim 2

A method for preparing a perovskite-type crystal dielectric ceramic to selectively obtain a formulation consisting essentially of (1-m) parts (Sr x Ca y Mn z )TiO 3 per m parts silicon-oxygen containing compound and having a relatively high dielectric constant together with a relatively low non-linear temperature coefficient, which comprises: (A) providing mixed powder composed of a material consisting essentially of (Sr x Ca y Mn z )TiO 3 , wherein x, y, and z satisfy the following relationships: 0.98<x+y+z<1.02, 0.34<y<0.4, and 0.0075<z<0.015, by combining suitable proportions of a strontium compound, a calcium compound, a titanium-oxygen containing compound of insufficient amounts of titanate compounds are selected in the previous steps, and a manganese compound to form a mixture, suitably mixing and pulverizing; (B) calcining by heating said mixed powder to a temperature of 1100° C. to 1200° C. and maintaining that temperature for at least two hours; (C) mixing the (Sr x Ca y Mn z )TiO 3 with a suitable amount of a silicon-oxygen containing compound such as CaTiSiO 5 , CaSiO 3 , or SiO 2 to obtain a formulation (1-m) parts of (Sr x Ca y Mn z )TiO 3 per m parts silicon-oxygen containing compound, wherein m is mole fraction, and such that x, y, z, and m satisfy the following relationships: 0.98<x+y+z<1.02, 0.34<y<0.4, 0.0075<Z<0.015, and 0.005<m<0.015; (D) reducing particle size; (E) forming and (F) sintering at a temperature range of 1280° C. to 1400° C. for two to eight hours.