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:
Feb. 11, 2003
Filed:
Jul. 02, 2001
Yutaka Kaneda, Kanuma, JP;
Keiichi Naito, Kanuma, JP;
Soichiro Kishimoto, Kanuma, JP;
Toshihiro Shinohara, Kanuma, JP;
Sony Chemicals Corp., Tokyo, JP;
Abstract
A bump formation etching mask is formed on the bump formation side of a metal foil having a thickness (t +t ) equal to the sum of the thickness t of a wiring circuit and the height t of the bumps to be formed on a wiring circuit. The bumps are formed by half-etching the metal foil from the bump formation etching mask side down to a depth corresponding to a predetermined bump height t A metal thin film layer formed of a different metal from the metal foil is formed on the bump formation side of the metal foil, thereby providing a bump-attached wiring circuit board with which stable bump connections are possible, and there is no need for bothersome operations, such as plating pretreatments.