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:
Dec. 20, 1994
Filed:
Oct. 27, 1993
Christina M Boyko, Conklin, NY (US);
Richard W Carpenter, Johnson City, NY (US);
Raymond T Galasco, Vestal, NY (US);
Krystyna W Semkow, Poughquag, NY (US);
Herbert Wegener, Endwell, NY (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
The present invention relates to a method for selectively electroetching a metal from an electrical device having the steps of: immersing the electrical device in an etching solution; immersing a cathode in the etching solution; applying an etching potential to a preselected area of the metal; and maintaining a passivation potential at the metal to remain unetched. The metal to remain unetched is not electrically connected to the preselected area and the passivation potential does not equal the etching potential. The present invention further relates to a method of forming an electrical connection to the inner layers of a multilayer circuit board having a copper foil surface layer and copper containing inner layers.