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. 08, 1998
Filed:
Jun. 07, 1995
Applicant:
Inventors:
Shiro Kobayashi, Isehara, JP;
Masami Kawaguchi, Hadano, JP;
Assignee:
Hitachi, Ltd., Tokyo, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H05K / ;
U.S. Cl.
CPC ...
29852 ; 216 17 ; 427 97 ; 430318 ;
Abstract
The invention presents a method of finishing a printed circuit board by using a soluble chloride added to a soft etching solution, the soluble chloride provides a source of chloride ions that beneficially combine with plated copper to form a protective CuCl layer. The protective layer is desirably used to prevent overetching of a copper film in a via or through-hole of a printed wiring board.