Low alpha tin

Abstract

A non alpha controlled Tin including Tin and a trace amount of Polonium may be converted to a low alpha emission Tin by concentrating and removing at least some of the Polonium. The non alpha controlled Tin may be a raw material or a solder bump upon a semiconductor wafer, chip, or carrier. The Polonium may be concentrated by oxidizing an exterior portion of the non alpha controlled Tin. If the non alpha controlled Tin is a raw material, the oxidized exterior portion of the non alpha controlled Tin may be stripped. If the non alpha controlled Tin is a solder bump, the oxidized exterior portion of the solder bump may be removed by applying flux to the solder bump, reflowing the solder bump to dissolve the oxidized exterior portion and the concentrated Po into the flux, and cleaning the flux from the solder bump.

Dependencies are inferred from the claim text.