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:
Jun. 07, 1988
Filed:
Oct. 16, 1986
Shinsuke Yano, Nagoya, JP;
Susumu Nishigaki, Nagoya, JP;
Narumi China Corporation, Nagoya, JP;
Abstract
Partially crystallized ceramic articles is prepared by firing at low temperatures of 800.degree. to 1100.degree. C., a mixture consisting essentially of, (a) 40 to 50 wt. % of powdered, noncrystalline glass consisting essentially of 10 to 55 wt. % of at least one selected from the group consisting of CaO and MgO, 45 to 70 wt. % of SiO.sub.2, 0 to 30 wt. % of Al.sub.2 O.sub.3, 0 to 30% of B.sub.2 O.sub.3 and up to 10% impurities, the powder size of said glass being at least 4.0 m.sup.2 /g in terms of specific surface area measured by the BET Method; and (b) 60 to 50 wt. % of powdered Al.sub.2 O.sub.3 and the ceramic article is composed essentially of a noncrystallized glass phase, alumina and at least one of crystallized glass phase among anorthite, wollastonite, cordierite and mullite formed by partially crystallizing the glass (a). The ceramic articles exhibit a very high flexural strength well comparable with alumina substrate, together with greatly improved dielectric constant and thermal expansion and thus are especially useful in making multi-layer ceramic substrates for electronic applications.