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:
Jan. 23, 1979
Filed:
Jan. 30, 1978
William P Dugan, Pomona, CA (US);
John A Muhr, Claremont, CA (US);
General Dynamics Corporation, Pomona, CA (US);
Abstract
A process for manufacturing printed circuit boards having plated through-holes. An epoxy glass substrate is laminated on opposite surfaces by a thin copper foil and subsequently apertures are drilled through the laminated substrate where the plated through-holes are desired. The exposed surfaces of the apertures are electroless copper plated. Then by means of a photoresist, the desired circuit images and the apertures are exposed and the initial electroless copper plating is removed again. The apertures and the desired circuit images are again plated by electroless copper plating to establish an initial copper thickness. The apertures in the desired circuit images are then electro-copper plated to the approximate thickness of the photoresist and preferably so that their thickness is less than the thickness of the photoresist. The copper plating is then electro-solder plated. The remaining photoresist is removed and the now exposed laminated copper foil is chemically removed to provide the finished printed circuit board.