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

摘要

To provide a Ni ball having a low ± dose and high sphericity even when it contains impurity elements other than Ni in certain amounts. The Ni ball contains an element U, a content thereof being 5 ppb or less, and an element Th, a content thereof being 5 ppb or less, wherein a purity of the Ni ball is 99.9% or more but 99.995% or less, an ± dose thereof is 0.0200 cph/cm2 or less, a content of either Pb or Bi, or a total content of both Pb and Bi is 1 ppm or more, and a sphericity thereof is 0.90 or more, in order to prevent any software errors and reduce connection failure.