HIGH DIELECTRIC CONSTANT VERY LOW FIRED X7R CERAMIC CAPACITOR, AND POWDER FOR MAKING

摘要

The invention includes a dielectric ceramic powder mixture comprising at least ninety weight percent essentially pure barium titanate powder having an average particle size of from 0.2 to 1.2 microns, from 0.2 to 2.5 weight percent of barium lithium borosilicate flux; from 0. 1 to 0. 3 weight percent of MnC03; a grain growth inhibitor such as niobium oxide or other niobate compound; and, 0.4 to 1.2 weight percent of an additive selected from the group consisting of a rare earth oxide, yttrium oxide, a combination of rare earth oxides, and a combination of yttrium oxide and rare earth oxides, such that ions of the additive(s) have an average ionic radius of about 0.97 angstroms. The dielectric ceramic powder provides a start powder for making very low firing multilayer ceramic capacitors satisfying X7R performance requirements.