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. 17, 2007
Filed:
Aug. 04, 2004
Keiichi Sasaki, Kanagawa, JP;
Masato Kamiichi, Kanagawa, JP;
Yukihiro Hayakawa, Kanagawa, JP;
Ershad Ali Chowdhury, Kanagawa, JP;
Keiichi Sasaki, Kanagawa, JP;
Masato Kamiichi, Kanagawa, JP;
Yukihiro Hayakawa, Kanagawa, JP;
Ershad Ali Chowdhury, Kanagawa, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
In order to provide a circuit substrate with a satisfactory step coverage by the protective layer and the anti-cavitation film in an edge portion of wirings and a liquid discharge head utilizing such circuit substrate, the invention provides a method for producing a circuit substrate provided, on an insulating surface of a substrate, with a plurality of elements each including a resistive layer and a pair of electrodes formed with a predetermined spacing on said resistive layer, including a step of forming an aluminum electrode wiring layer on the resistive layer, a step of isolating the electrode wiring layer by dry etching into each element, and a step of forming the electrode wiring into a tapered cross section with an etching solution containing phosphoric acid, nitric acid and a chelating agent capable of forming a complex with the wiring metal.