Reduction stable low dielectric constant ceramic material for co-firing with copper electrodes

摘要

A reduction stable COG ceramic material has a composition in the rhombic bronze phase-forming region of the barium oxide-lead oxide-neodymium oxide-titanium oxide system with addition of a glass frit of certain type as a sintering aid. A low dielectric constant, reduction stable COG ceramic material, for co-firing with copper electrodes and having a composition in the rhombic bronze phase-forming region of the BaO-PbO-Nd2O3-TiO2 system with addition of a glass frit belonging to the ZnO-B2O3-SiO2, K2O-Na2O-BaO-Al2O3-ZrO2-ZnO-SiO2-B2O3 or Li2O-BaO-B2O3-SiO2 system, has the formula (Ba1-yPby)6-xNd8+2x/3Ti18O54 + z wt.% TiO2 + p wt.% glass frit, where x = 0.6 to 2.1 exclusive, y = 0 to 0.6 exclusive, z = 0 to 5.5 exclusive and p = 3 to 10. Independent claims are also included for (i) production of the above reduction stable COG ceramic material additionally containing 10-20 wt.% Nd2Ti2O7, in which the glass frit-free portion of the material, consisting of a raw material mixture of BaCO3, Nd2O3, TiO2 and Pb3O4 or PbCO3, is calcined at 1150 deg C to form the composition (in mol%) (BaO)6.61(PbO)5.71(NdO1.5)31.3(TiO2)56.39 or (BaO)7.39(PbO)6.38(NdO1.5)29.05(TiO2)57.18 and then 3, 6 or 8 wt.% glass frit is added; and (ii) production of the above reduction stable COG ceramic material additionally containing 50-80 wt.% Ba4.5Sm9Ti18O54, in which the glass frit-free portion of the material, consisting of a raw material mixture of BaCO3, Nd2O3, Sm2O3, TiO2 and Pb3O4 or PbCO3, is calcined at 1150 deg C to form the composition (in mol%) (BaO)11.37(PbO)3.57(NdO1.5)13.56(SmO1.5)14.48(TiO2)57.01 and then 3, 6 or 8 wt.% glass frit is added.