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. 06, 2010
Filed:
Oct. 06, 2004
Applicants:
Daisuke Souma, Tochigi, JP;
Takahiro Roppongi, Tochigi, JP;
Hiroshi Okada, Mooka, JP;
Hiromi Kawamata, Mooka, JP;
Inventors:
Daisuke Souma, Tochigi, JP;
Takahiro Roppongi, Tochigi, JP;
Hiroshi Okada, Mooka, JP;
Hiromi Kawamata, Mooka, JP;
Assignee:
Senju Metal Industry Co., Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L 23/48 (2006.01); H01L 23/52 (2006.01); H01L 23/40 (2006.01);
U.S. Cl.
CPC ...
Abstract
A Sn—Ag—Cu based lead-free solder ball which does not undergo yellowing of its surface when formed into a solder bump on an electrode of an electronic part such as a BGA package. The solder ball has excellent wettability and does not form voids at the time of soldering, even when it has a minute diameter such as 0.04-0.5 mm. It has a composition comprising 1.0-4.0 mass % of Ag, 0.05-2.0 mass % of Cu, 0.0005-0.005 mass % of P, and a remainder of Sn.