Abstract: A via interconnection of a glass-ceramic wiring board is made by blending a copper powder to a vehicle including a cellulose derivative, adding a metal oxide powder having a mean particle diameter of from at least 1 &mgr;m to at most 4 &mgr;m to the vehicle and blending them, adjusting the viscosity of the vehicle by adding the cellulose derivative and filling them to a via; and sintering the via at a temperature of at least 900° C. to at most 1060° C., and forming the via interconnection.

Abstract: A glass-ceramic wiring board includes an insulating substrate, a via disposed in the insulating substrate and a via interconnection filling the interior of the via. The via interconnection is sintered material having metal particles. The metal particles have a cross-sectional area per one metal particle surrounded by a metal particle boundary of less than 2000 &mgr;2, which can be determined by cutting, etching and examining a cross-section of the via.

Abstract: In a ceramic wiring board which comprises a copper via, breaks and defects of via interconnections resulting from enlargement of copper particles in the interior of the via during sintering, are prevented.

Abstract: In a ceramic wiring board which comprises a copper via, breaks and defects of via interconnections resulting from enlargement of copper particles in the interior of the via during sintering, are prevented.

Abstract: In a ceramic wiring board which comprises a copper via, breaks and defects of via interconnections resulting from enlargement of copper particles in the interior of the via during sintering, are prevented. For this purpose, alumina of mean particle diameter from 1 &mgr;m to 4 &mgr;m is disposed in the interior of the via interconnection after sintering at an average interval of 7.4 &mgr;m or less.

Abstract: This invention provides a conductor paste having a low resistivity (about 10 .mu..OMEGA..cm or below) and capable of retaining a film thickness of 25 to 35 .mu.m after baking by composing the paste from 85 to 96 wt. % of a metal powder having a resistivity of 10 .mu..OMEGA..cm or below and 4 to 15 wt. % of an organic vehicle containing 5 to 13 wt. % of a binder. The invention also provides a process for producing the above-described conductor paste, in which 85 to 96 wt. % of a metal powder having a resistivity of 10 .mu..OMEGA..cm or below and 4 to 15 wt. % of an organic vehicle containing 5 to 13 wt. % of a binder are forcibly passed between the barrel-shaped rolls in a kneader and thereby kneaded to form a paste, wherein the roll interval in the kneader is adjusted so that the smallest distance between the adjoining barrel-shaped rolls becomes 5 .mu.m or less and the shear rate therebetween is set at 1,000 s.sup.-1 or more.