Creating components for confusion?

Paul Boughton

No one is denying that the principle behind reducing the flow of hazardous substances into landfill sites is a laudable one. Although we may not agree that the RoHS directive was the right place to startit is now a reality and we have to comply.

The fallout from the legislation could be severe and mean bad news for electronic design and assembly in the UK; especially for SMEs with a modest product portfolio.

As we see itthe central problem lies in that the RoHS directive seems to have been forced through without much joined-up thinking as to the way it would be implemented and the sequence of activities required. This has led to serious gaps and problems arising along the way.

Obsolescence

The first of these is the question of enforced obsolescence. Many of the semiconductors used on current designs are relatively old.

Many of these devices (or more preciselypackages) will not be migrated to RoHS compliant versions. In the best case this will require new PCB design to accommodate the new packages.

More worryinglyif key components such as processors or peripherals are made obsolete then the knock on effect of having to modify firmware and software could cripple a small producer.

Quite simplyconverting to lead-free is often not an exercise in migration but a fundamental re-engineering job.

Consequentlythe process is both lengthier and significantly more expensive than it initially appears.

To mitigate the cost of this exercise a full product review and re-development might be appropriate.

Utilising current components and modern assembly techniques it should be possible to re-coup the re-development costs from lower unit production costs but this critically depends on production volume.

Realistically this means that if you haven’t started product conversion yet it is probably too late to meet the deadline.

Legislation and timing

There are a number of issues compounding the problem which have been addressed in the legislation and its timing.

The lack of an industry wide standard part numbering requirement for RoHS compliant has added to the confusion and expense for designersdistributors and assemblers.

It is now clear that the omission of a standardised marking/part code system from the directive was a serious oversight.

Enforcement would have avoided the current situationwhere each semiconductor manufacturer seems to have a different methodology.

Picking through these various numbering systems to source compliant products – if they are available at all – is a time consuming and costly process.

Many semiconductor manufacturers are still unable to offer timescales for the introduction of RoHS compliant parts. “They will be compliant for the July deadline” is a frequent commentbut in reality as designers and assemblers we needed them 12 months ago at least in volumes to allow designdevelopmenttesting and qualification to be completed.

Finally there is the equally bewildering issue of exemptionswhich have proven to be a minefield of conflicting views.

Take after-market automotive productsfor example a CD player for example. If it is ‘primarily’ used in a vehicle then it would be exempt under ELVbut if people started to buy it and use it in reasonable volume elsewhere would it then need to be RoHS compliant? Can the producer rely on intent or does actuality rule?

It is examples like this – where woolly thinking is given primacy over good planning and common –- that have allowed this situation to arise.

Deadlines

Nowwith deadlines fast approaching it is too late to turn back the clockbut there is still time to learn lessons.

The most fundamental of these is that if such initiatives are to succeed then all parties must collaborate from the beginningnot just at the major manufacturer levels but also that of the SMEs.

u Norcott Technologies group was founded in July 1997 and in 1999 it established an in-house electronic assembly service.

Although primarily for internal product build we expanded the offering into subcontract assembly for our existing design customers.

In 2005 the assembly activities were separated out into a specialist division – Norcott EMS. It now provides services for national and multi-national companies across the whole of Europe. It also provide services to high technology start-ups and major research laboratories.

Pete Lomas is managing director of Norcott EMS based in CheshireUK. www.norcottems.co.uk

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