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:
Sep. 11, 2012
Filed:
Dec. 10, 2010
Applicants:
Hiroto Narieda, Tokyo, JP;
Yuta Sonoda, Tokyo, JP;
Masaaki Izaki, Tokyo, JP;
Inventors:
Assignee:
Dowa Metaltech Co., Ltd, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C23G 1/20 (2006.01); C23F 4/00 (2006.01); C23F 1/34 (2006.01);
U.S. Cl.
CPC ...
Abstract
A Cu-based materialis immersed into an alkali hydroxide solution with a concentration of 3.0 to 37.5 mass % and a HOsolution with a concentration of 3.0 to 50.0 mass % is added in the alkali hydroxide solution, a temperature of the alkali hydroxide solution when the Cu-based material is immersed ranges from 60 to 105° C., a ratio A/B between a mol number A of alkali hydroxide in the alkali hydroxide solution and a mol number B of HOin the HOsolution is 10 or more, and where a mol number of Sn in the Sn layer is C and a mol number of Sn in the CuSn layer is D, B≧C×2+D×6.