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. 17, 1998
Filed:
May. 12, 1995
NEC Corporation, Tokyo, JP;
Abstract
A multi-layer wiring substrate includes an insulating layer which is essentially formed of a silica sintered product, and a conductor layer formed on an upper surface of the insulating layer from an electrically conductive material. The multi-layer wiring substrate is produced by forming a green sheet from a starting powder such as an ultrafine powder of amorphous silica having an average particle size of several to tens nm, and firing or calcining the green sheet at a temperature of 800.degree. to 1,200.degree. C. in an atmosphere containing steam to provide a silica sintered product which is sintered to a sufficient extent and has a high strength. The starting powder has a composition which comprises 95.0 to 99.5% by weight of a fine silica powder, 0.05 to 5.0% by weight of an alkaline earth metal compound, or comprises 95.0 to 99.0% by weight of a fine silica powder and 1.0 to 5.0% by weight of B.sub.2 O.sub.3. The silica sintered product has a sufficiently high strength and a dielectric constant of 4.0 at 1 MHz.