Patent ID: 6251816
Filing Date: 2001-06-26
Classification: C04B,H01G

Abstract:
A dielectric ceramic powder comprising:a) a first powder mixture consisting essentially ofa1) from 51 to 99 weight percent (Ba.sub.(1-m) Ca.sub.m Ti.sub.(1-m) Zr.sub.m)O.sub.3, the molar fraction m ranging from 0.20 to 0.35, respectively by weight of said first powder mixture,a2)a first additive selected from the group consisting, respectively by weight of said first powder mixture, of the group of up to 30 weight percent strontium titanate, up to 10 weight percent bismuth titanate, and mixtures thereof,a3) a dual-component sintering flux consisting essentially of barium borate and zinc silicate, the barium borate making up from 0.5 weight percent to 5.0 weight percent and the zinc silicate making up from 0.5 weight percent to 4 weight percent of said first powder mixture; andb) a second powder mixture consisting essentially ofb1) a precursor powder selected from the group consisting, respectively by weight of said second powder mixture, essentially of from 82.5 weight percent to 99 weight percent of a powder of xBaO.yTiO.sub.2.zNd.sub.2 O.sub.3, x ranging from 0 mole percent to 30 mole percent, y ranging from 45 mole percent to 95 mole percent, and z ranging from 5 mole percent to 50 mole percent,b2) a second additive selected from the group consisting, respectively by weight of said second powder mixture, essentially of up to 2.5 weight percent bismuth titanate, up to 6 weight percent barium zirconate, and mixtures thereof,b3) said dual-component sintering flux, the barium borate making up from 0.5 weight percent to 5 weight percent and the zinc silicate making up from 0.5 weight percent to 4 weight percent of said second powder mixture,wherein said first and said second powder mixtures together amount to at least 99 weight percent of said dielectric ceramic powder and the weight percent of each of said first and said second powder mixtures is from 0 to 100 weight percent,so that by sintering said dielectric ceramic powder, there may be provided a low TCC dielectric ceramic body having selected electrical and linear properties by having chosen the relative amounts of each of said powder mixtures and having chosen the relative amounts of each of the environmentally friendly and TCC stabilizing dual-component fluxes.