Appeal No. 2004-0777 Page 4
Application No. 09/731,726
that can be within the claimed tin weight percent range. See
Table 1 of Akamatsu. Like appellants, Akamatsu teaches that a
soft error rate can be reduced by employing a tin solder with a
low alpha decay, such as less than 0.1 cph/cm2 alpha decay. See
Table 1 of Akamatsu.
The examiner has reasonably determined that one of ordinary
skill in the art would have been led to employ a tin and silver
containing alloy having a composition within the ranges as set
forth in representative claim 1 because Ogashiwa reasonably
teaches: (1) using an amount of silver (0.1 to 8 weight percent)
that overlaps the claimed 1.5 to 2.8 weight percent range, and
(2) using an amount of tin that exceeds 90 weight percent of the
composition as fairly explained by the examiner in the answer.
Based on the combined teachings of Ogashiwa and Akamatsu, the
examiner has further determined that Akamatsu would have led one
of ordinary skill in the art to employ alloy components such that
alpha ray amounts are lower than 0.1 cph/cm2 including less than
0.01 cph/cm2 as here claimed, to limit soft errors. Given the
result effectiveness of limiting alpha ray emission as taught by
Akamatsu, we agree with the examiner that one of ordinary skill
in the art would have arrived at solders with alpha ray amounts
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