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:
Oct. 12, 1993
Filed:
Jul. 30, 1991
Kazuhiro Ando, Ibaraki, JP;
Takamasa Kawakami, Ibaraki, JP;
Yasuhiro Shouji, Ibaraki, JP;
Yasuo Tanaka, Tokyo, JP;
Takeo Kanaoka, Tokyo, JP;
Norio Sayama, Tokyo, JP;
Mitsubishi Gas Chemical Co., Inc., Tokyo, JP;
Abstract
A process for producing a multilayered printed circuit board which comprises using, as an intermediate layer, an inner-layer board obtained by chemically oxidizing the surface of a copper foil constituting an outermost layer of an inner-layer board having a printed circuit formed in the copper foil, thereby to form on the surface a finely roughened layer constituted by a copper oxide of a brown to black color, and then reducing the copper oxide constituting the finely roughened layer in an atmosphere in which a reducing gas is present.