Ag ball , Ag nuclear ball , flux -coated Ag balls , flux -coated Ag nuclear ball , solder joints , form solder , solder paste , Ag paste and nuclear Ag paste

摘要

Providing an Ag ball having a low alpha dose and a high sphericity regardless of impurity elements having an amount equal to or more than a predetermined value except for Ag. In order to suppress a soft error and reduce an connection fault, a content of U is equal to or less than 5 ppb, a content of Th is equal to or less than 5 ppb, a purity is equal to or more than 99.9% but equal to or less than 99.9995%, an alpha dose is equal to or less than 0.0200 cph/cm 2 , a content of either Pb or Bi or a total content of both Pb and Bi is equal to or more than 1 ppm, and a sphericity is equal to or more than 0.90.