Adopting Lead‐Free Electronics: Policy Differences and Knowledge Gaps

Abstract

For more than a decade, the use of lead (Pb) in electronics has been controversial: Indeed, its toxic effects are well documented, whereas relatively little is known about proposed alternative materials. As the quantity of electronic and electrical waste (e‐waste) increases, legislative initiatives and corporate marketing strategies are driving a reduction in the use of some toxic substances in electronics. This article argues that the primacy of legislation over engineering and economics may result in selecting undesirable replacement materials for Pb because of overlooked knowledge gaps. These gaps include the need for: assessments of the effects of changes in policy on the flow of e‐waste across state and national boundaries; further reliability testing of alternative solder alloys; further toxicology and environmental impact studies for high environmental loading of the alternative solders (and their metal components); improved risk assessment methodologies that can capture complexities such as changes in waste management practices, in electronic product design, and in rate of product obsolescence; carefully executed allocation methods when evaluating the impact of raw material extraction; and in‐depth risk assessment of alternative end‐of‐life (EOL) options. The resulting environmental and human health consequences may be exacerbated by policy differences across political boundaries. To address this conundrum, legislation and policies dealing with Pb in electronics are first reviewed. A discussion of the current state of knowledge on alternative solder materials relative to product design, environmental performance, and risk assessment follows. Previous studies are reviewed, and consistent with their results, this analysis finds that there is great uncertainty in the trade‐offs between Pb‐based solders and proposed replacements. Bridging policy and knowledge gaps will require increased international cooperation on materials use, product market coverage, and e‐waste EOL management.

Metal stocks and sustainability

“…Tin's other major use, rapidly approaching dominance, is as the principal component of electronic solders, which have traditionally had a composition of 60% tin͞40% lead ratio by weight. The electronics industry is now moving toward very high-concentration tin solder formulations that avoid the use of toxic lead but must meet a complex set of physical requirements, including a low melting point, good ''wetting'' properties, freedom from ''whisker'' growth, and stability in service (30,31). An alloy that meets these conditions is a tin-silver-copper eutectic consisting of Ϸ96% (by weight) tin, 3% silver, and 1% copper.…”

Leaching Assessments of Hazardous Materials in Cellular Telephones

“…Therefore, regulatory agencies have focused on replacing Pb in electronic products (2). It is becoming clear that, even after Pb is replaced in electronic products, e-waste may remain classified as "hazardous" because of the presence of other toxic materials that may leach out, depending on the test protocol.…”

Green Electronics through Legislation and Lead Free Soldering

“…The substitutes to Sn-Pb solders must satisfy various engineering and other criteria which includes similar properties to current alloys, same temperature range as Sn-Pb, same or better reliability and equal or lower cost, compatibility with standard finishes, ease of application with wetting properties similar to current Sn-Pb including fluidity and cohesive force and stability [24]. Technically, lead-free solders must have a coefficient of thermal expansion (CTE) that matches the joining components, must be able to resist thermal cycling, have sufficient creep resistance to maintain thermomechanical loading in the longer periods in the field of use [23].…”

“…www.clean-journal.com behavior of these intermetallic structures under elevated temperatures or longer term use is very low, hence, needs more research [24].…”