The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 20, 1991
Filed:
Jul. 06, 1989
NGK Insulators, Ltd., Aichi, JP;
Abstract
In a multilayered ceramic substrate having a ceramic substrate fireable in low temperatures and a metal member for input/output brazed to the ceramic substrate, an intermediate layer including a ceramic component is arranged between the ceramic substrate and the metal member in such a manner that thermal coefficients .alpha..sub.1, .alpha..sub.2 and .alpha..sub.3 between a room temperature and near a brazing temperature of the metal member, the ceramic component in the intermediate layer and the ceramic layer, respectively, maintains a relation of .alpha..sub.1 >.alpha..sub.2 >.alpha..sub.3. Moreover, the ceramic substrate fireable in low temperatures is constructed by first ceramic layer having a flexural strength more than 25 kg/mm.sup.2 and a second ceramic layer having a dielectric constant less than 7. In these constructions, the multilayered ceramic substrate having a sufficient adhesion strength between the metal member and the ceramic substrate and a good reliability can be obtained, while advantages of the ceramic substrate fireable in low temperatures can be maintained.