A STUDY OF LEAD-CONTAMINATION IN LEAD-FREE ELECTRONICS ASSEMBLY AND ITS IMPACT ON RELIABILITY

摘要

With the RoHS/WEEE Directives potentially outlawing lead from electronics produced and imported in the EU by 2006 or 2007 and foreign competition driving the implementation of lead-free electronics assembly around the world, additional questions regarding the integrity and reliability of various alloy compositions continue to arise. In short, the issue of which alloy(s) to select continues to loom. This paper shall take an in-depth view of Sn/Ag, Sn/Ag/Cu and Sn/Cu alloys and compare the reliability testing results and process considerations for these. First, however, this paper will address the often-misunderstood issue of lead contamination of lead-free free assemblies. As will be discussed, the contamination of lead-free solder joints from lead on components or PWBs can reduce reliability and result in solder joint failure.