"CHIPS: IBM gets the lead out of its chip packages"

A lead-free process that lowers the cost of packaging flip-chip devices has entered volume production at IBM Corp.'s East Fishkill, N.Y., fab. As one of the first production facilities to use the technique, Controlled Collapse Chip Connection New Process (C4NP), IBM projects that it can achieve 99.7 percent yields. Flip-chip solder bumps are deposited by electroplating, which involves dipping wafers into a chemical bath, eletro-depositing the bumps, then disposing of the toxic chemicals in the bath. C4NP, which has been under development since 2004, uses a nozzle to inject molten solder into a wafer-scale mold. Bumps can then be applied to the entire wafer.
Text: http://www.eetimes.com/showArticle.jhtml?articleID=201002357