Title:
HIGH-PURITY TIN OR TIN ALLOY AND PROCESS FOR PRODUCING HIGH-PURITY TIN
Document Type and Number:
WIPO Patent Application WO/2007/004394
Kind Code:
A1
Abstract:
A high-purity tin or tin alloy characterized in that the respective contents of U and Th are simultaneously 5 ppb or less and the respective contents of Pb and Bi simultaneously 1 ppm or less, and that the purity thereof is 5 N or higher (provided that the gas components of O, C, N, H, S and P are excluded). Further, there is provided a high-purity tin or tin alloy characterized in that the α-ray count of high-purity tin with cast structure is 0.001 cph/cm2 or less. Recent semiconductor devices, as density and capacity enhancements are promoted, increasingly encounter the danger of soft error generated by the influence of α-ray from a material lying in the neighborhood of semiconductor chips. Especially, the demand for purity increase of a solder material or tin used adjacent to semiconductor devices is strong, and a material of reduced α-ray is demanded. Accordingly, it is intended to obtain a high-purity tin or tin alloy having α-ray level of tin reduced in conformity with the above demands and obtain a process for producing such a high-purity tin.
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Inventors:
SHINDO YUICHIRO (JP)
TAKEMOTO KOUICHI (JP)
TAKEMOTO KOUICHI (JP)
Application Number:
PCT/JP2006/311912
Publication Date:
January 11, 2007
Filing Date:
June 14, 2006
Export Citation:
Assignee:
NIPPON MINING CO (JP)
SHINDO YUICHIRO (JP)
TAKEMOTO KOUICHI (JP)
SHINDO YUICHIRO (JP)
TAKEMOTO KOUICHI (JP)
International Classes:
C25C1/14; C22B25/08; C22C13/00
Foreign References:
| JPH11343590A | 1999-12-14 | |||
| JP2001082538A | 2001-03-27 | |||
| JPH07280998A | 1995-10-27 | |||
| JP3528532B2 | 2004-05-17 | |||
| JP3227851B2 | 2001-11-12 | |||
| JP2913908B2 | 1999-06-28 | |||
| JP2754030B2 | 1998-05-20 | |||
| JPH11343590A | 1999-12-14 | |||
| JPH09260427A | 1997-10-03 | |||
| JPH01283398A | 1989-11-14 | |||
| JPS6247955B2 | 1987-10-12 | |||
| JPS621478B2 | 1987-01-13 | |||
| JP2001082538A | 2001-03-27 | |||
| JPH07280998A | 1995-10-27 |
Other References:
See also references of EP 1900853A4
Attorney, Agent or Firm:
OGOSHI, Isamu (Toranomon 9 Mori Bldg. 3F 2-2, Atago 1-chome, Minato-k, Tokyo 02, JP)
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