Dielectric ceramic body including TIO2 dispersion in crystallized cordierite matrix phase, method of producing the same, and circuit board using the same

Abstract

A dielectric ceramic body prepared by firing a mixture of a cordierite glass powder and a TiO.sub.2 powder, or a mixture of these powders and a RE.sub.2 Ti.sub.2 O.sub.7 powder (RE representing a rare earth element), wherein particles of the TiO.sub.2 powder or particles of the TiO.sub.2 powder and the RE.sub.2 Ti.sub.2 O.sub.7 powder are dispersed in a matrix phase of crystalline cordierite produced from the fired cordierite glass powder. In the first case, the cordierite glass powder and the TiO.sub.2 powder have a proportion which satisfies 70.ltoreq.x<100, 0<y.ltoreq.30, and x+y=100, where x and y represent contents in weight % of the cordierite glass powder and said TiO.sub.2 powder, respectively. In the second case, the cordierite glass powder, TiO.sub.2 powder and the RE.sub.2 Ti.sub.2 O.sub.7 powder have a proportion which satisfies 50.ltoreq.x<100, 0<y.ltoreq.30, 0<z.ltoreq.40, and x+y=100, where z represents a content in weight % of the RE.sub.2 Ti.sub.2 O.sub.7 powder.

Dependencies are inferred from the claim text.