RoHS Implementation Challenges

Implementation of the RoHS presents special challenges for small and medium sized companies. Limited staff and dependence on outsourced services creates cost burdens for smaller OEMs. The first major challenge is conversion of existing product Bills of Materials. Conversion is usually much more involved than just re-specifying RoHS compliant parts on the AVL. For some components, it may be difficult to eliminate the offending RoHS element (Cd, Pb, etc.) and still have the product function successfully. Major corporations have been active in proposing and receiving special exemptions from the TAC committee but further additions seem less likely without substantial data. A second major challenge is the “due diligence” process of collecting, compiling and evaluating supplier certificates of compliance and materials declarations for the multiple suppliers of hundreds of components. New database systems must be added, populated and sustained. Since most “due diligence” protocols advocate random component testing, arrangements must be made to screen and chemically test sample lots from most suppliers. Testing at the assembly level for extremely low levels of the six RoHS elements at the homogenous constituent layer level is problematic for many tiny electronic components. In some cases, it may take 5-10 components to make up the minimum quantity required for chemical testing. Yet, Pb is exempt in some layers while forbidden in other layers of the same component. A third major challenge is assessing the reliability impact of conversion to RoHS. Thankfully, national and international consortia have addressed many of the major technical issues but each company must still address the impact of tin whisker mitigation strategies, SAC alloy fatigue behavior and higher reflow temperatures on their specific products. In most cases, converted products must be completely re-qualified to assess the impact of these changes on reliability. Introduction Most large, multinational corporations began RoHS compliance programs well before the publication of European Directive 2002/95/EC (RoHS) in January 2003. However, many small and medium sized companies have only recently begun to tackle the vast amount of work required to ensure their organizations are in compliance with RoHS/WEEE. There are a number of practical reasons cited for waiting ranging from the hope that legislation will be delayed to the financial need to have others do the basic materials science research required for conversion. Since at past companies, the authors have participated in the early stages of several small companies, we felt it beneficial to present the issues involved in RoHS implementation from the perspective a small to medium sized company. A number of workshops and conferences have provided a general outline of the work that must be done to bring products into compliance with the Directive. Websites such as the one sponsored by The British Ministry of Trade and Industry have provided valuable guidance. As evidence by this 12 International Lead Free Conference, IPC, JEDEC, NEMI and other organizations around the world have been actively engaged in addressing the many process and reliability issues associated with eliminating lead from solder joints. IEC working groups are working on chemical analysis methods for detecting the substances banned by RoHS. Among the key points that can be gleaned from these presentations is the need to do, at minimum, at least the following to achieve compliance: • Product Conversion including establishing Design for RoHS compliance guidelines and a review of each existing product Bill of Materials (BOM) for RoHS compliance • Establish and validate lead free assembly and inventory management processes. • Gather, compile and store “Due Diligence” documentation in a data management system • Set up an audit program to screen and chemically test incoming components • Contemplate individual product reliability issues that can occur from materials and process changes.