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:
Jul. 24, 1990
Filed:
Sep. 01, 1989
Antoon Mattelin, Oostkamp, BE;
Siemens Aktiengesellschaft, Berlin and Munich, US;
Abstract
A method for manufacturing printed circuit boards has a double etch process to form interconnection wiring. A metal layer is formed on the substrate. An etch resist layer is applied to the metal layer. The layer is selectively removed to allow for selective etching of the metal layer. A second etch resist layer is applied to the metal layer not previously etched. The side walls of the metal layer are also protected by the resist. The second etch resist layer is then selectively removed to allow for a second etching of the metal layer. After the second etching, the interconnection wiring remains in the desired pattern. The second etch resist layer, which may be tin, can be left on the wiring to improve component soldering.