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:
Oct. 10, 1995
Filed:
May. 20, 1994
Keishi Danjo, Kamakura, JP;
Takashi Enomoto, Sagamihara, JP;
Tatsuo Murata, Isehara, JP;
Masayuki Shimamune, Tokyo, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
An aqueous mixture etchant containing hydroiodic acid and ferric chloride is suitable for etching ITO to form a minute electrode pattern as used in a liquid crystal display device. When the etchant has caused a decrease in etching performance due to a compositional change, it can be effectively regenerated by replenishing appropriate amounts of hydrochloric acid and pure water, or an appropriate amount of a dilute hydrochloric acid at a constant concentration, while minimizing the use of hydroiodic acid and ferric chloride which are rather expensive compared with hydrochloric acid and pure water.