Cu BALL
AssigneeSenju Metal Industry Co., Ltd.
InventorsHiroyoshi KAWASAKI, Takahiro HATTORI, Takahiro ROPPONGI, Daisuke SOMA, lsamu SATO
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Abstract
To provide Cu ball that has less α dose and high sphericity even when containing at least a certain amount of impurity elements other than Cu. Even when the purity thereof is 99.995% or less and U and Th contents are 5 ppb or less in order to suppress any software errors and decrease connection failure, α dose is 0.0200 cph/cm2 or less. Further, the sphericity of the Cu ball is unexpectedly improved by making the purity not more than 99.995%.
Claims20
1-10. (canceled)
A Cu ball characterized in that the Cu ball contains Pb and/or Bi contents of a total of 1 ppm or more, sphericity of 0.95 or more, a purity from 99.9% or more to 99.995% or less, α dose of 0.0200 cph/cm2 or less, U content of 5 ppb or less and Th content of 5 ppb or less.
Dependencies are inferred from the claim text.