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:
Sep. 22, 1987
Filed:
Sep. 15, 1986
James F Battey, Los Altos, CA (US);
Norvell J Nelson, Palo Alto, CA (US);
Daniel J Barnett, San Jose, CA (US);
PSI Star, Fremont, CA (US);
Abstract
Copper etching process and product particularly suitable for use in the manufacture of printed circuit boards. The copper is etched in a liquid etchant, and the crystal structure of the copper is selected and carefully controlled to provide an anisotropic etch and a relatively high vertical-to-lateral etching ratio. In one disclosed embodiment, the etching solution contains nitric acid, copper nitrate or sulfuric acid, a polymer and a surfactant, and the copper has a top surface crystal structure with predominantly (111) and (200) orientations and relatively little (220) orientation. In another disclosed embodiment, the etching solution contains hydrogen peroxide and sulfuric acid, and the copper foil has a top surface crystal structure with predominantly (311) and (511) orientations. A printed circuit board manufactured in accordance with the invention has a copper foil with a crystal structure selected to provide anisotropic etching and a relatively high vertical-to-lateral etching ratio with a given etching solution bonded to a substrate, with portions of the copper foil being etched away by the etching solution to form the desired foil pattern.