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. 31, 1999
Filed:
Dec. 09, 1997
Tetsuo Satoh, Tokyo, JP;
Citizen Watch Co., Ltd., Tokyo, JP;
Abstract
A bump is formed on a semiconductor wafer which has a pad electrode thereon. The method includes the steps for coating a first organic film on a semiconductor water; drying the first organic film; applying an excimer laser to a portion of the first organic film substantially corresponding to the pad electrode to thereby form a first opening in the organic film; forming at least one metallic film on the first organic film and the opening; coating a second organic film on the metallic film; drying the second organic film; applying an excimer laser to a portion of the second organic film substantially corresponding to the first opening to thereby form a second opening in the second organic film; and providing and melting solder at the second opening to form a solder bump. Since the openings of the organic films are formed by the excimer laser, the openings can be formed in a short time with high accuracy. Thus, the bump with high quality can be formed at a low cost.