Here is an article from the "Printed Circuit Design & Manufacture" magazine.
http://pcdandm.com/pcdmag/mag/0411/0411ourline.pdf
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Politicians As Technologists
Joe Fjelstad kicked off his PCB Design Conference East
keynote speech, “The Impact of Lead-Free on PCB
Design,” by stating that the sun would rise tomorrow.
But after that, any other good news was obscured by clouds.
Fjelstad, a veteran interconnect and packaging specialist
and co-founder of the startup Silicon Pipe, told the audience of
PCB designers, engineers and manufacturers that they’d better learn all they can about
lead-free assembly processes, and pronto. The European Union has decreed that
beginning July 1, 2006, electronic products containing lead, mercury, cadmium, hexavalent
chromium, PBB or PBDE will not be sold in its member countries.
Among Fjelstad’s observations: There is no drop-in replacement for lead. Because
of the higher temperatures needed for lead-free solders and finishes, delamination and
warpage are real threats. All current lead-free solders are more prone to voiding than
leaded solders. Tin whiskers are more prevalent with lead-free plating. New inspection
criteria will be needed, because lead-free simply looks different. The use of leaded
components with lead-free processes can result in CTE mismatches. Component manufacturers
may have to maintain separate leaded and lead-free product lines. Studies
have found lead-free PCBs to be extremely brittle after a month of storage at 100°C.
The surfaces of wave soldering machines may be damaged by lead-free alloys.
The hits kept coming. Fjelstad estimated the conversion to lead-free would come
at a steep price. “One hundred billion dollars,” he intoned. “And how might this be
better spent?”
But if anyone in the audience thought the move to lead-free was the result of a reasoned,
logical risk analysis, Fjelstad set them straight. He pointed out that Europe’s leadfree
movement was born with the lead-poisoning death of a child in Denmark. The
grief-stricken parents effectively lobbied against all lead-containing materials and the EU
parliament was moved by their emotional argument. The parliament even ignored its
own scientific council, Fjelstad explained, caught up in the influence of “groupthink.”
“They charged ahead, knowing lead was a poison and they could do no wrong,”
said Fjelstad.
So, what evidence exists that lead-free solder and finishes will reduce pollution? None,
according to Fjelstad. In fact, the alternatives may prove even worse for the environment,
especially with the higher temperatures required by all lead-free processes. And the EU has
mandated recycling of electronic products, which would seem to negate the need to eliminate
lead, especially in an industry that consumes only 0.5% of all the lead used each year.
But the law is the law, and the EU is a huge electronics market. The lead-free
deadline has created a drive for more knowledge about these processes, from assemblers
upstream to PCB designers. At PCB East, the lead-free assembly classes drew big
crowds, including many PCB designers, eager to absorb any lead-free information.
Fjelstad expects many companies – especially in the mil/aerospace, transportation
and medical fields – to seek waivers from the EU. A self-described Don Quixote tilting
at windmills, Fjelstad plans to write to the Airbus consortium explaining that he’ll
never fly on any of their planes if they go lead-free. But he noted that some companies
in Japan are already manufacturing products completely free of leaded solders, finishes
and components. It can be done.
In the end, Fjelstad challenged the audience to avoid groupthink and play devil’s
advocate even when – especially when – the other side of an argument claims to have
the moral high ground. And he recommended using common sense when dealing with
lead, mercury and other useful but potentially dangerous substances.
“All things are toxic,” Fjelstad said. “It’s just a matter of whom it’s toxic to.”
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Sasha
Sasha
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Too many people debate as if the point is to show who is smarter, rather than which conclusion is correct.
