Examining the environmental impact of lead-free soldering alternatives

Abstract

In 1999, the Surface Mount Council identified the issue of lead-free electronics as an emerging area for concern and evaluation. This was triggered by the initial European Union's (EU) proposal for a Directive on Waste from Electrical and Electronic Equipment (WEEE) and by the Japanese focus on environmental marketing and on recycling, which has resulted in timetables for lead elimination. The present EU directive on the elimination of lead from electronics by 2008 has added further urgency to this issue. From an industrial ecology perspective, it is essential to evaluate the environmental impact of the proposed alternatives and to compare this with that of the present Sn/Pb solder. Industrial ecology is the multidisciplinary study of industrial systems and economic activities, and their links to fundamental natural systems. Based on this definition, it is important to study the environmental impact of lead-free electronics through their entire life cycle. Factors such as alloy availability, processing considerations, energy use and potential ground water contamination must be considered. Based on these criteria, lead-free products are not more environmentally friendly than the present electronics soldered with Sn/Pb. Thus, the focus of future regulation should be on recovery and recycling of the metals at end-of-life as required in the WEEE rather than the elimination of lead-based solder.