Design for the environment: evaluating cleaner technologies in the PWB industry

The design for the environment (DFE) printed wiring board (PWB) project is a voluntary partnership among the US Environmental Protection Agency (EPA), the PWB manufacturing industry, public-interest groups, and the University of Tennessee Center for Clean Products and Clean Technologies. The goal of the DFE PWB Project is to evaluate the risk, performance, cost, and effects on resource conservation of alternative processes for "making holes conductive" (MHC) in PWB fabrication. PWB manufacturers have traditionally used an electroless copper process to deposit a conductive surface on drilled through-holes prior to electrolytic plating. Electroless copper processes typically employ formaldehyde as a reducing agent and require large amounts of water and energy. A number of emerging or existing technologies exist, however, that can perform the MHC function and substitute for the electroless copper process. This paper describes the methods used by the PWB project partners to develop a cleaner technologies substitutes assessment (CTSA) of the MHC substitute processes and presents current progress on the risk characterization and performance demonstration components of the CTSA.