International Business Machines Corporation

John Conrad Kutt

Stephen G Starr

Robert Henry Zalokar, Jr

Craig J Gilmond

Jeff R Kelby

Pat N McCabe, Jr

An evaporation system has fluorocarbon polymer-coated surfaces to permit easy removal of deposited metal. Evaporated lead-tin films will adhere strongly enough to a Teflon-coated shield so that the lead tin does not fall off during vacuum deposition but the bond between the lead-tin and the Teflon is still weak enough so that the lead-tin coating is easily peeled off, leaving the Teflon coating on the shield intact. The peeled lead-tin is substantially free of contamination so it can be reused, for example, in a subsequent deposition.

Metals recovery system

A process of Pb/Sn evaporation eliminates haloes in the manufacture of solder bump interconnects. This robust process of forms solder bump interconnects and reduces critical molebdnum mask sensitivity. Vacuum evaporation through which Pb/Sn C4 pads are deposited is performed by maintaining parallel temperature gradients between the molybdenum mask and silicon wafer, thus resulting in elimination of connecting haloes and yield losses.

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Essex Junction, VT, United States of America

John Conrad Kutt