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. 07, 1989
Filed:
Aug. 28, 1986
Kazuo Kondo, Nagoya, JP;
Hisaharu Shiromizu, Inuyama, JP;
Asao Morikawa, Komaki, JP;
Tsuneyuki Sukegawa, Kasugai, JP;
NGK Spark Plug Co., Nagoya, JP;
Abstract
A process for producing a multilayer circuit board composed of crystallized glass and copper-metallized circuit patterns, which comprises: (1) providing a green sheet of a crystallizable glass powder; (2) providing a copper paste comprising copper component (copper and/or copper oxide) and a glass powder in a proportion by weight of the copper component to the glass powder 95:5 to 75:25, copper oxide being calculated on copper; (3) printing a circuit pattern of the copper paste of step (2) on the green sheet of step (1); (4) coating on the green sheet of step (3) an insulating paste to form an insulating layer except for regions assigned for through holes; (5) printing on the insulating layer of step (4) a circuit pattern of the copper paste of step (2) and filling said holes with the copper paste make a conductive connection through said holes; (6) decomposing the binders by heating the product of step (5) under an oxidizing atmosphere at 400.degree.-850.degree. C.; and (7) heating the product of step (6) at 850.degree.-1050.degree. C. under a reducing atmosphere for a period of time sufficient to reduce copper oxide, sinter the product of step (6) and crystallize said glasses. After step (5), pairs of steps (4) and (5) are repeated to make multilayer circuit boards.