Traditionally wafer bumps are made from Pb containing solders. Over 20 years ago IBM recognized that Pb-210 has a decay chain resulting in a 5.4 MeV alpha particle that induces soft errors. A variety of efforts to produce and characterize low alpha Ph ensued. Work at Honeywell over the past several years has shown that low alpha lead activity does not follow the decay signature predicted from Pb-210 secular equilibrium. Data are presented indicating that smelting has a minimal effect on Pb-210/Po-210 secular equilibrium and that other trace radionuclides are the alpha source. The implications of these data to possible alpha emitter sources in lead free solders are discussed, along with a method developed by Honeywell to remove alpha emitters from lead free solder components. (C) 2004 Elsevier B.V. All rights reserved.