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. 29, 1997
Filed:
Jun. 26, 1995
Naoki Uchiyama, Sanda, JP;
Masayoshi Kohinata, Sanda, JP;
Akihiro Masuda, Ohmiya, JP;
Yoshiaki Okuhama, Kobe, JP;
Seishi Masaki, Kobe, JP;
Masakazu Yoshimoto, Kobe, JP;
Mitsubishi Materials Corporation, Tokyo, JP;
Daiwa Fine Chemicals Co., Ltd., Kobe, JP;
Abstract
An electroplating solution (A), comprises an aqueous solution consisting essentially of lead phenolsulfonate: 1 to 250 g/liter in terms of Pb content; tin phenolsulfonate: 0.1 to 250 g/liter in terms of Sn content; phenolsulfonic acid: 20 to 300 g/liter; polyoxyethylene polyoxypropylene alkylamine: 1 to 50 g/liter; a 1-naphthaldehyde derivative: 0.001 to 1 g/liter; and an aldol sulfanilic acid derivative: 0.1 to 30 g/liter; or an aqueous solution (B) consisting essentially of lead methanesulfonate: 1 to 250 g/liter in terms of Pb content; tin methanesulfonate: 0.1 to 250 g/liter in terms of Sn content; methanesulfonic acid: 20 to 300 g/liter; polyoxyethylene polyoxypropylene alkylamine: 1 to 50 g/liter; and an aldol sulfanilic acid derivative: 0.1 to 30 g/liter. Each of the electroplating aqueous solutions (A) and (B) contains 50 ppb or less radioactive isotopes, whereby Pb-Sn alloy bump electrodes with improved uniformity in height and improved surface smoothness can be formed on a surface of a semiconductor wafer.