METHOD FOR PRODUCING TIN FROM WHICH LOW-ALPHA RADIATION IS EMITTED BY USING VACUUM REFINING

摘要

The present invention concerns a production method for tin from which low-alpha radiation is emitted by using vacuum refining, the method comprising the steps of: preparing a tin starting material that emits a large amount of alpha radiation and contains a large amount of impurities; putting the tin in a crucible and then placing same in a vacuum furnace; and removing impurities that have a higher vapour pressure and a lower boiling point than tin, via steam in the vacuum furnace; wherein the majority of impurities such as lead and bismuth are removed from the tin by using the differences in the vapour pressures of various elements, thereby suppressing the emission of alpha radiation to the maximum extent and so making it possible to prevent the occurrence of soft errors in electronic products.