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:
May. 17, 1977
Filed:
Aug. 26, 1975
Applicant:
Inventors:
Assignee:
Perstorp AB, Perstorp, SW;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C23F / ;
U.S. Cl.
CPC ...
156630 ; 156247 ; 156253 ; 156645 ; 156644 ; 156659 ; 156665 ; 204 24 ; 204 / ; 204 / ; 20412965 ; 252 792 ;
Abstract
A method for the production of through holes in a laminate comprising an insulating base provided with a thin metal layer on at least one side, said laminate being intended for printed wiring. The method is characterized in that the thin metal layer is provided with a firmly adhering and protective foil or layer of a material being chemically different from the thin metal layer and that so-called burrs in the thin metal layer obtained during a mechanical machining of the holes are removed by dissolution whereupon the protective foil or layer can be removed.