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:
Mar. 12, 1996
Filed:
Mar. 29, 1994
Yoshiaki Yamade, Hyogo, JP;
Yoichi Moriya, Hyogo, JP;
Sumitomo Metal Industries Ltd., Osaka, JP;
Abstract
The ceramic substrate comprising a glass and a crystal is characterized by the glass comprising a MgO--Al.sub.2 O.sub.3 --SiO.sub.2 --B.sub.2 O.sub.3 --R.sub.2 O-base glass(R:alkali metal) and containing a 2MgO.2Al.sub.2 O.sub.3.5SiO.sub.2 crystal (cordierire) as the crystal. Due to the composition, the softening point of the glass becomes less than 720.degree. C. and the porosity decreases, so that the substrate can be dense. As a result, the coefficient of thermal expansion thereof can be close to silicon, the specific inductive capacity thereof can be small and the substrate can be excellent in transverse strength, moisture resistance, water resistance, etc. And, due to the lowered softening point, a ceramic substrate having the above characteristics can be produced even by sintering at between 800.degree. C. and 1000.degree. C., and ceramic substrate having an inner circuit interconnection made of Ag or Cu, etc. can be produced.