Assembly Options and Challenges for Electronic Products With Lead-Free Exemption

Due to safety and reliability concerns, various classes and/or applications of electronic products are excluded from the European Union's Restriction of Hazardous Substances (RoHS) regulations requiring the elimination of lead (Pb). However, the majority of electronic devices are now Pb-free. As a result, manufacturers attempting to maintain tin-lead (SnPb) based electronics face an increasing challenge to procure parts and products with Pb-based solder. This paper reviews the challenges of producing Pb-based electronic equipment, the reliability concerns with Pb-free electronics, and the options that manufacturers have for maintaining reliable, Pb-based production. In particular, the paper examines mixed soldering processes and the re-balling of Pb-free electronic parts. While Pb-free electronics present risks, it is our conclusion that the risks are manageable and are lower than those incurred by maintaining an increasingly obsolete Pb-based manufacturing process.