RoHS: 10 Years Later - Process Control Equipment Corrosion Issues Remain

摘要

The European Union RoHS directive took effect in 2006, and of the 6 restricted materials, the elimination of lead from electronic devices took the most development effort and had the worst degrading effect on electronic hardware reliability. One negative impact was the brittleness of the lead-free solder alloys that replaced the industry favorite, ductile Pb-Sn eutectic alloy. Another was the unexpected occurrence of creep corrosion on printed circuit boards using alternative PCB surface finishes. Along with the implementation of RoHS, the miniaturization of circuits, and the expansion of the pulp and paper industry in developing countries with high-levels of sulfur-bearing gaseous pollution, have all led to increased rates of corrosion-related electronic equipment hardware failures associated with particulate and gaseous contamination. Process controls manufacturers have taken a two-pronged approach to mitigating these failures: (1) by making the products more robust against contamination and high humidity levels; and (2) by gaining better understanding of the allowable levels of contamination, temperature and humidity under which this equipment can operate reliably. This paper will discuss the role RoHS has played in electronic equipment reliability and how changes to air quality standards and air monitoring has led to improvements in environmental controls for process computer and control rooms, motor control centers, network and switchgear equipment resulting in reduced equipment failures, less downtime, and higher productivity.