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. 27, 1976
Filed:
Jul. 11, 1974
Applicant:
Inventors:
John J Frantzen, North St. Paul, MN (US);
Lee C Barton, St. Anthony Village, MN (US);
Assignee:
Buckbee-Mears Company, St. Paul, MN (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C23F / ;
U.S. Cl.
CPC ...
156 11 ; 156 16 ; 156345 ;
Abstract
A sheet of metallic material having a thickness T is covered on one side by an etchant resist and on the opposite side by an etchant resist and a removable shield. Etching is first performed on the side with only the etchant resist layer. Next, the shield is removed and the material is etched from both sides to produce an opening having a minimum dimension less than the thickness T of the material.