[tinwhiskers] Re: AW: [RoHSUSAPushback] FW: IPC expresses concerns on possible ROHS revisions
- From: "Bob Landman" <rlandman@xxxxxxxxxxxxxxxxx>
- To: <RoHSUSAPushback@xxxxxxxxxxxxxxx>, <tinwhiskers@xxxxxxxxxxxxx>, <klaus-reindl@xxxxxxxxxxx>, "'Henning Leidecker'" <henning.w.leidecker@xxxxxxxx>, "'Brusse, Jay A. \(GSFC-560.0\)[QSS]'" <jay.a.brusse@xxxxxxxx>
- Date: Thu, 7 Aug 2008 12:56:01 -0400
Dear Klaus,
Thank you for your kind comments. I noted that you said that
"the bulk of the transition to Pb-free is or will be done. So far, we have not
heard of an unexpected catastrophe?"
I would remind everyone that there have been some well documented failures,
including at nuclear power plants. See
http://nepp.nasa.gov/WHISKER/failures/index.htm and this website is always
being updated with new facts of failures.
The problem is that NASA knows of many failures but are not permitted to share
them all as the manufacturers and military/aerospace agencies who come to them
for help and failure analysis, forbid them to disclose the problems.
What manufacturer wants to wash it's dirty laundry in public?
So, how will we know of these failures? Will Sony and Toshiba and Philips and
Siemens tell us? Or will the products that fail, fail intermittantly, fail and
be thrown away in some landfill (not recycled)? Isn't this more likely to
happen since we have had failures and there is no lead free solder that
prohibits whiskers (and yes, even lead solders have very tiny (5 micron
gnarly)whiskers, I know that).
So, how many failures does it take to convince the EU they have made a terrible
mistake?
Inquiring minds would certainly like to know where that trip point is! 100?
1000? 10,000? A million? Do they care at all?
Bob Landman, President
Senior Member, IEEE PES
H&L Instruments, LLC
34 Post Road, PO Box 580
North Hampton, NH 03862-0580
(tel) 603-964-1818 (fax) 603-964-8881
www.hlinstruments.com
________________________________
From: RoHSUSAPushback@xxxxxxxxxxxxxxx On Behalf Of Klaus Reindl
Sent: Saturday, August 02, 2008 2:46 AM
To: RoHSUSAPushback@xxxxxxxxxxxxxxx
Cc: 'SMART Group smart-e-link'; '(Leadfree Electronics Assembly Forum)';
'TechNet E-Mail Forum'
Subject: AW: AW: [RoHSUSAPushback] FW: [tinwhiskers] IPC expresses concerns on
possible ROHS revisions
Bob,
thank you for your valuable inputs.
For European manufacturers they may look a bit biased, given that the RoSH
legislation has been put in practice pretty much.
For the US, it may be a well-balanced view, since (in my view), RoHS has not at
all found broad acceptance in the US.
Of course, also in Europe the Pandora?s box of problems with the main
replacement for the eutectic PbSn solder system?Sn outerleads plating and SAC
or doped SnCu solders are known: Poorer wettability, poorer reliability under
slow dT/dt excursions, lower performance in drop tets, Sn whiskers on
non-soldered, Sn plated Cu or Alloy 42 lead surfaces.
In order to eliminate or at least decrease those problems, many measures, based
on material sciences, have been introduced on the component and board
soldering sides.
But as you state, the problems could not be solved completely yet. Especially
the Sn whisker issue is still open. The whisker stress tests ?called
accelerating, without any acceleration factor being known?are more of a
pacifier for worried moods rather than a scientifically based approach.
By the way, Sn whiskers also were reported with eutectic SnPb plating and
soilders, albeit on a much lower scale.
But it is fruitless to again and again scrape in open wounds.
At least here in Europe and in Japan and soon in China and Korea and California
(to name a few), the bulk of the transition to Pb-free is or will be done.
So far, we have not heard of an unexpected catastrophe?
It only leaves us engineers to stay vigilant, in order to avoid more regulation
without valid physics background, being enforced on the industry.
Best regards,
Klaus Reindl
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