Examining the environmental impact of lead-free soldering alternatives

The Surface Mount Council has identified the issue of lead-free electronics as an emerging area for concern and evaluation This has been triggered by the 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. From an industrial ecology perspective, it is essential to evaluate the environmental impact of the proposed alternatives and to compare those 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 reflect on the environmental impact of lead-free electronics through their entire life cycle. This includes factors such as alloy availability, processing considerations, energy use and ground water contamination. 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.