Rocky road to RoHS compliance

The Restriction of Hazardous Substances (RoHS) Directive is complete and will take effect in the UK next year.

Although there is wrangling over what is exempt, the vast majority of consumer products sold after that date in Europe will be illegal if they include more than a fraction of a per cent of lead, mercury, cadmium, hexavalent chromium, or two specified bromine compounds.

Although responsibility for compliance rests with firms at the consumer end of the supply chain, the work required to make products compliant has largely settled on the shoulders of product manufacturers, component distributors and component makers.

The biggest headache for companies which make products comes from purging banned substances from circuit boards - by finding components which do not include the banned substances and also going over to lead-free processing.

Planning this transition requires information, then making the transition requires compliant components.

Generally, on both these scores, "the big semiconductor companies are the best and the big brand-name passive suppliers are generally on course", says Greg Nicol, group purchasing manager for distributor Abacus. "The manufacturers that are consistently furthest behind are electromechanical manufacturers; particularly connectors. There is quite a confused message out there."

This said: "There are still semiconductor manufacturers in denial", says Colin Weaving technical director at distributor Future Electronics.

So, why are electromechanical components lagging semiconductors?

Arrow's Catrin Kristensen

"The situation for non-semiconductor suppliers is a complex one," says Catrin Kristensen, marketing director for passive and electromechanical components (pemco) at distributor Arrow.

Part of this complexity stems from the variety of electromechanical components available. "There are a lot of different technologies involved," says Kristensen.

Semiconductor makers share the same small pool of materials between all types of chips, whereas electromechanical component manufacturers have, amongst other things, a wide variety of case plastics, metal parts and contact materials to deal with.

Plastics can be particularly difficult as the dyes and fillers used can contain banned substances, and plastics suppliers are a long way up the supply chain from RoHS and in some cases fail to see the need to respond.

Across pemco suppliers, "we have received good information to the part number level from ten per cent of suppliers", says Kristensen. "Only these know what they are doing and when they are doing it."

Amongst the others, she says the majority of suppliers have a roadmap for some products and some of these are down to the part number. Not all are consistent across their technologies. "All are doing something, but there are some who cannot supply [any] information on what they will do," says Kristensen.

The sheer number of non-semiconductor parts makes life complex for distributors. "Within Arrow, we have double the number of pemcos than semiconductors," she says, "so that is twice the workload with data, stock, keeping things updated and keeping the customer informed."

Per Lindman, marketing manager at Ericsson's power module division, gives Electronics Weekly  a view on passive component availability.

"Ceramic [chip] capacitors are no problem," he says. "We have some problems with chip resistors, some of our vendors are not offering lead-free." With inductors "we have good availability and what we see definitely is an increase in price".

Even if all component makers started providing data down to component level for all their products today, there are still uncertainties for product assemblers, particularly over what products need to be RoHS-compliant.

Nevison of Farnell and Afdec

"What we have found is, customers are asking us more and more questions where we go to the DTI and they can't help," says Gary Nevison who heads RoHS compliance work at distributor Farnell and at distribution umbrella group Afdec. "They put it back to us to get a legal ruling."

A moot point on whether low-cost microprocessor development tools need to be compliant illustrates the problem. "We are trying to find out who can make a legal ruling," says Nevison. "Is an environmental specialist lawyer in the UK sufficient, or do we need to go to Europe?"

For many PCB assemblers, the issue of RoHS compliance boils down to timing the adoption of a lead-free soldering process.

"Our customers," says Arrow's Kristensen, "find it very difficult to run lead-inclusive and lead-free together. A lot of the customers want to have a date which they will be lead-free after, and they want that date to be close to today. [For some] that is the middle of this year."

For those product manufacturers capable of managing stock control issues arising from a gradual change-over, almost all lead-free components except BGAs (ball-grid arrays) are compatible with lead-inclusive soldering. "The ideal [for them] is putting more and more lead-free components into a lead-inclusive process, then change the soldering when they are all lead-free," says Abacus' Nicol.

However and whenever each assembler decides to become fully RoHS-compliant, there will be some components that are not available in the appropriate form, particularly during through the period when the bulk of assemblers change over.

"Lead-free products are six to eight weeks, but availability will be difficult to call when the majority go over and lead-times could go out," says Afdec's Nevison.

He sees less-well known Far-Eastern component makers with compliant ranges picking up business when big firms are slow to comply. But he has a warning based on Afdec member experience.

"If you don't know a supplier from the Far East, you are taking a risk if you accept supposedly-compliant products are compliant," he says. "Some random testing is advisable. End-users need to make sure their distributor has done something, or do tests themselves."

Any component shortages are likely to put up prices, but is there anything else that might increase costs?

"Our customers are concerned that there is going to be a change in pricing," says Nevison. "Generally, at this moment in time there is little change, but at some stage there is going to be a recouping of costs [by component makers]."

What are suppliers doing? Having RoHS-compliant components available, and a convincing compliance roadmap for those yet to emerge, will help to retain customers as the 2006 deadline approaches. Omron is one firm confident it can meet information and component demands. "I have an Excel file showing exactly the details of our planning; which products are RoHS-compliant and when," says Victor Viveen, product marketing manager at relay maker Omron.   Vistor Viveen from Omron Viveen sees why some electromechanical part makers are struggling. His firm has been designing out cadmium, mercury and chromium from its product range for eight years. "We started already many years ago," he says. "Changing to cadmium-free is very challenging. To still have the performance, we have to do a lot of testing." Dave Hoskins, technical sales manager at Cypress Semiconductor, is equally confident: "We have a spreadsheet for every device and a date for its intended rollover." Cypress intends to produce lead-free and lead-inclusive components in parallel. Some "customers really don't want to go lead-free", Hoskins says. Unusually, but not uniquely, amongst chip makers, Cypress is using nickel-palladium-gold to plate its leadframes. "Customers really like the finish," says Hoskins, "I haven't seen any issues with NiPdAu." Lead-free tin coatings are the lower-cost alternative, but for some people the spectre of tin whisker growth has not yet been laid to rest.

And another thing: Part Numbering Part numbering has been a big issue in the build-up to RoHS-compliance. After a huge amount of work by companies, industry representatives and European organisations, one fact has emerged: the whole thing is a mess. There is no consistency between markets, manufacturers, or even the divisions of some companies. As such, there is no substitute for a Sherlock Holmes-like attention to detail when planning and executing the change-over. This is needed all the way down the supply chain, and from the first lead-free order until the last lead-inclusive component is flushed out of the system.