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:
Aug. 05, 2003
Filed:
Oct. 26, 2001
Applicant:
Inventor:
Wilfried Hofmann, München, DE;
Assignee:
NFT Nanofiltertechnik Gesellschaft mit beschrankter Haftung, Bad Homburg, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C25F 3/00 ;
U.S. Cl.
CPC ...
C25F 3/00 ;
Abstract
A method for the production of filters in which a blank of n- or p-doped etchable semiconductor material is connected as an anode or a cathode according to doping. The method includes contacting a first side of the blank with an etching solution in which a counterelectrode is arranged to electrochemically etch the first side, and supplying activation energy to generate minority charge carriers to the blank during the etching process. The activation energy supplied per unit time is reduced with increasing etching progress.