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.

Date of Patent:
Jul. 19, 2016

Filed:

Feb. 14, 2011
Applicant:

Gaku Kanou, Ibaraki, JP;

Inventor:

Gaku Kanou, Ibaraki, JP;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C25C 1/14 (2006.01); C22C 13/00 (2006.01); B23K 35/26 (2006.01); B23K 35/36 (2006.01); B23K 35/40 (2006.01);
U.S. Cl.
CPC ...
C22C 13/00 (2013.01); B23K 35/262 (2013.01); B23K 35/36 (2013.01); B23K 35/40 (2013.01); B23K 2201/40 (2013.01);
Abstract

Disclosed is tin characterized in that a sample of the tin after melting and casting has an α dose of less than 0.0005 cph/cm. Since recent semiconductor devices are highly densified and of high capacity, there is an increasing risk of soft errors caused by the influence of α rays emitted from materials in the vicinity of semiconductor chips. In particular, there are strong demands for high purification of solder materials and tin for use in the vicinity of semiconductor devices, and demands for materials with lower α rays. Accordingly, an object of the present invention is to clarify the phenomenon of the generation of α rays in tin and tin alloys, and to obtain high-purity tin, in which the α dose has been reduced, suitable for the required materials, as well as a method for producing the same.


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