Pulsed Electrodeposited Sn-Cu Alloys for Use as Pb-Free Component Finishesin Microelectronic Applications

摘要

In recent years there has been a considerable push to develop replacements for Sn-Pb soldersrncurrently in use in microelectronic packaging. At this time, alloys based on the Sn-Ag-Cu (SAC)rnsystem seem to be favoured. The Pb-free push is in response to recent legislation in Japan andrnEurope banning its use in most electronics. Equally important is the replacement of Pb-bearingrnalloys that serve as a finish for solderable electronic component leads. This is a difficult task,rnsince Pb additions benefit the performance of Sn. For example, Pb lowers the melting point,rnenhances solderability and reduces problems with whiskering. Finally, any Pb-free replacementrnfinish must be compatible with SAC alloys. This paper considers pulsed electrodeposited Sn-Curnas a candidate.