Dielectric ceramic body including TiO.sub.2 dispersion in crystallized cordierite matrix phase, method of producing the same, and circuit board using the same

摘要

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 Ti.sub.2 powder or particles of Ti.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 Ti.sub.2 powder have a proportion which satisfies 70≦x 100. 0 y≦ 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≦x 100, 0 y≦30, 0 z≦40, and x+y=100, where z represents a content in weight % of the RE.sub.2 Ti.sub.2 O.sub.7 powder.