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. 20, 2011
Filed:
Jul. 16, 2008
Masataka Kato, Naka-gun, JP;
Makoto Terui, Yokohama, JP;
Ryoji Kanri, Zushi, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A filter capable of separating or filtering micro foreign particles in a flow passage is provided. A first mask and a second mask are formed on a silicon substrate by dry etching. Before performing the dry etching, a resist of the first mask is subjected to a heat treatment performed at a temperature equal to or higher than a glass transition point. A resist of the second mask is not subjected to such a heat treatment. This processing simultaneously forms in the substrate a groove portion and a wall having a hole that is located in the groove portion. A silicon material located beneath a wide portion of the first mask remains as a wall portion separating the holes.