Ni BALL, Ni NUCLEAR BALL, SOLDER JOINT, FOAM SOLDER AND SOLDER PASTE

摘要

Provided is an Ni ball that has a low α-ray amount, even though containing a definite amount or more of impurity elements other than Ni, and has a high sphericity. An Ni ball wherein: the U content is controlled to 5 ppb or less; the Th content is controlled to 5 ppb or less; the purity is controlled to 99.9-99.995% inclusive; the α-ray amount is controlled to 0.0200 cph/cm2 or less; the content of Pb and/or Bi is controlled to 1 ppm or more; and the sphericity is controlled to 0.90 or more, in order to suppress soft errors and reduce connection failures.