ICT Evening Seminar: Restriction of Hazardous Substances.
The Institute of Circuit Technology held an evening seminar on 28 th February 2006 in Arundel, UK on the subject of Restriction of Hazardous Substances (RoHS) legislation and its impact on the circuit industry.
ICT Chairman, Andrew Hall introduced two complementary papers from the internationally recognised experts Martin Goosey of Rohm & Haas and Len Pillinger of BSI.
Martin Goosey, as a representative of a major provider of potentially hazardous process chemicals to a broad spectrum of the electronics manufacturing industry, spoke from the supplier’s perspective.
Remarking that end-of-life electrical and electronic equipment was the fastest growing waste stream in Europe, Martin pointed out that RoHS, originally introduced as part of the WEEE regulations but now a separate single-market directive, was intended to reduce the impact of “EEE” on the environment by restricting the use of defined hazardous substances during manufacture – stopping their use at the beginning of the cycle rather than worrying about their disposal at the end.
Reviewing the listed substances: lead, cadmium, mercury, chromium VI and brominated flame retardants PBB and PBDE, he provided many illustrations of where they could be found in electrical and electronic components and assemblies; some obvious, some relatively unexpected – especially in seemingly innocuous examples of metal finishes where trace amounts of co-deposited stabilisers like lead and mercury in plated tin finishes could push them outside the limits of acceptability.
In many instances, interpretation of what materials contained hazardous substances was straightforward, but clarification of the terminology of “homogenous” materials, to which concentration limits of proscribed substances had been applied, presented many challenges and much discussion had taken place regarding what could and could not be considered capable of being mechanically disjointed into different materials.
Key issues for suppliers were to ensure compliance of their own product, but equally to ensure compliance in the products which they purchased, and an integrated approach was essential. Misinformation was a possible consequence of the long international supply chains typical in the electronics industry. Although, in UK law, if “due diligence” could be demonstrated it was possible to pass responsibility for non-compliance along the supply chain, this was not the case in other EC states. The new IPC1752 Materials Declaration Management procedure offered a format for consistent material declaration data exchange between supply chain participants, and it was hoped that this would become adopted universally.
Martin’s concluding comments made the point that RoHS is just one step towards a whole philosophy of green manufacturing and sustainability, where the principle of “cradle to cradle” supersedes that of “cradle to grave”.
Len Pillinger, in characteristically ironic style, entitled his presentation “RoHS – Someone Else’s Problem?” and described suppliers’ obligations within the supply chain, both to themselves and to their customers, and the role of BSI in helping people to understand and to comply with the directive.
In UK, the National Weights and Measures Laboratory would be responsible for the enforcement of RoHS compliance, although their resources were limited and it was not expected that they would get off to a flying start in July 2006. However, it could be presumed with reasonable confidence that competitors would scrutinise each other’s observance of the regulations and be keen to report any non-compliance.
There had been some confusion about product categories and exemptions, and it seemed that there was a general lack of knowledge of basic materials science. A relevant example was the assumption that an aluminium heat sink contained only aluminium, whereas it could in fact be alloyed with more than the tolerated percentage of lead.
There remained a strong anti-RoHS lobby, from bodies such as the US military, and USAF Airworthiness Advisory AA-05-01 took the cautious line: “The safety of USAF equipment must not be sacrificed in the transition to lead-free solder practices. Though there are many alternative solder alloys available to replace traditional tin-lead, none of them has passed the reliability testing required of aerospace-quality hardware.”
From BSI’s position as a standards authority, a significant consequence of the elimination of lead was that over 1000 test methods, particularly those for solderability and thermal shock testing, were potentially invalidated. A suggested fix was to define two reference alloys: SAC 305 (melting point 217 deg C) for reflow-type processes, and Sn0.7Cu (melting point 227 deg C) for wave-type processes, to enable people to demonstrate their products’ suitability for lead-free soldering, and a list of supplementary criteria so that people could continue to use established standards. BSI Product Services offered a “RoHS Trusted Kitemark” scheme to help manufacturers to understand the RoHS Directive and to demonstrate to their customers that they are taking all reasonable steps to comply with it. With the prospect of suffering “The Death of a Thousand Forms”, from the manufacturer’s own point of view the emphasis was on how to fill them in sensibly, what to mention and what not to mention in respect of establishing and maintaining credibility and not appearing an idiot. The end producer’s ability to comply with the RoHS Directive was dependent upon the entire supply chain of all parts, materials, sub-assemblies and components used to make the electrical and electronic equipment. From the point of view of the manufacturer’s relationship with his suppliers, it was a case of “once you’ve received your bit of paper, you’ve got to have a rationale for believing it!”
Andrew Hall closed the proceedings, thanking the speakers and the many delegates who attended, and acknowledged the generous support of Artetch Circuits in hosting the event.
Pete Starkey.
ICT Council.