RoHS: An update on this important Green Initiative
Criticism from Industry
The long-term reliability of some of the proposed lead-free solders is still being debated. Reliability is too broad a subject to detail here, but numerous technical papers and articles have addressed the topic over the past few years. Whether “tin whiskers” or “tin pest” are real problems or only theoretical ones, such as lead landfill leaching, remains to be seen.
Unfortunately, none of the lead solder substitutes has a reliability data base approaching the 2,000-year history of tin-lead solder. While lead-free reliability is merely questionable, lead-free solder overall costs will unquestionably be higher than for tin-lead solder. Hundreds of millions of dollars have already been spent in the conversion process, including training, process development, qualification testing, and new equipment.
On-going operating costs for more expensive and scarcer materials, higher use of thermal energy, and longer and less forgiving (lower yield) production processes over time will add billions of dollars to electronics equipment costs, dwarfing the conversion outlays. Higher costs and lower profits ultimately get passed along to customers as price increases.
Misapplied Resources: The invisible and non-recoverable cost of lead-free solder is what economists call an “opportunity cost.” The opportunity cost of lead-free solder is the hundreds of thousands of hours of skilled technical labor consumed in the lead-free preparation and conversion. The advances in electronics, manufacturing, new product development, and enhanced capabilities that these trained technical personnel might have achieved on other programs have instead been forfeited for a delusion.
Labeling for RoHS
RoHS does not require any specific product labeling. However, many manufacturers have adopted their own compliance marks to reduce confusion. Visual indicators in use today include explicit "RoHS compliant" labels, green leaves, check marks, and "PB-Free" .
RoHS Testing
Manufacturers of electrical and electronic equipment should check and monitor that no new products will exceed the maximum concentration limit of restricted substances such as Hexavalent Cr, Hg, Pb, Cd and Polybrominated Diphenylethers and Biphenyl ethers (PBDE and PBE) on their production processes.
XRF Screening (Preliminary Method). .Reliable, accurate, and fast screening for RoHS-restricted elements in all different kinds of materials is a daunting task. In practice, X-ray Fluorescence (XRF) analysis has proven to be an ideal analytical tool for fulfilling the main requirements of the industry. Minimal sample preparation and the direct measurement of solid samples distinguish XRF from any other elemental analysis technique.
With the shortest time-to-result and highest cost effectiveness, XRF screening (Figure 1 below) provides indications as to whether and where hazardous substances may exist in a product according to RoHS. It is especially suited, for instance, to acquiring a quick overview on end-products.
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Figure 1. X-ray fluorescence analysis provides indications of existence of whether and where hazardous substances may exist in a product.
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Figure 2: RoHS Testing Flow Chart
Companies can differentiate RoHS compliant products from non-compliant products via distinct marketing part numbers. RoHS compliant products are identified with a letter added into the original part numbering system, which can be easily identified through a datasheet or part numbering detail sheet. For example, Cypress Semiconductor adds a suffix letter “X” in its marketing part numbers.
RoHS Marketing Part = CY7C199C-15VXC
Non RoHS Marketing Part = CY7C199C-15VC
Conclusion
The EU RoHS Directive is a great achievement for the world as a whole. As more and more countries adopt these standards, tomorrow's landfills will be less contaminated and its industrial workers healthier. RoHS has paved the way as a global standard for phasing out several hazardous chemicals in the electronics supply chain.
Many companies have moved beyond RoHS, and there are numerous products on the market today that do not contain halogenated organic substances. Technical performances and fire safety standards can now be met with readily available alternative materials and components.
Companies doing business with European Union Member States will be required to comply with laws regarding the reduction of hazardous substances and the proper disposal of electronics waste. Late adopters of RoHS technology will risk inventory obsolescence, may experience their products being rejected at borders, and will be at high risk for loss of market share.
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