Thanks for your comments, Bob.
I posted the item without comment for purposes of getting discussion (such
as you have offered) going.
There are many in this forum who share your sentiments. (I saw as I was
writing that one of those stalwart souls has made this known to you... :-)
Yes, there has been a lot of information and misinformation put out over the
last several years that has become incorporated as part of a belief system
without fully testing the premises but then there are legislative forces at
work that are push many in our industry to put on a brave face and soldier on.
Until there is relief, there are few alternatives but we are agreed that
recycling is one of the big ones that can be used to cut the Gordian Knot)
Fortunately, the truth has a way of finding its way back to the surface no
matter what is tossed on it. (your response a case in point... :-)
Thanks again for sharing your thoughts and experiences, Bob.
Best wishes,
Joe
PS you may wish to duplicate your response on TechNet as not everyone is on
both forums.
In a message dated 1/26/2009 6:33:16 P.M. Pacific Standard Time,
[log in to unmask] writes:
Joe,
This article is full of misinformation. The following is one glaring
example:
"For commercial applications, lead-free components are plenty reliable. Tin
whiskers are not likely to grow on the components in your cell phone or
television. Plus, consumers don’t expect a commercial electronic product to last
more than a few years. In military and space applications, however, systems
have to last decades, facing extreme weather, temperature and vibration."
There is no truth to the statement that only extreme weather, temperature
and vibration cause tin whisker growth. How do you explain whiskering in air
conditioned computer rooms, in heart pacemakers (FDA recall of a Medtronic
device)? The fact is current science does NOT know what causes whiskers to
grow; if we did we could experiment with mitigation strategies much more easily.
Yes, high temp and humidity seem to accelerate growth but that is not
conclusive. I ask each of you - do you expect to throw away your refrigerator,
HDTV, automobile, heart pacemaker... "in a few years"? If we are doing this to
help the environment, tell me how throw-away electronics is good for the
environment? Anyone here for RECYCLING?
The following is a really silly statement:
" “Most companies in the exempt industries are using COTS parts,” said Gary
Nevison, legislation and environmental affairs manager at Newark. “They’re
using lead-free components primarily because nothing else is available. But
they take additional precautions to ensure high reliability.”
One of those additional precautions is dipping lead-free components in lead
to enhance reliability."
Dipping parts in lead isn't mitigation, it's remanufacturing! And yes, it's
VERY expensive. I find it somewhat good news that Avnet is considering a
lead dipping service for it's customers but what will happen to the original
part warranty? Because Avnet is an authorized distributor, will they also be
an authorized re-manufacturer?
Here's some more nonsense: "Lead was originally added to tin to mitigate the
tin whisker problem."
My word, that's news to me! Stop the presses! NO, that is NOT TRUE.
Tin-lead is a eutectic connection alloy that works well for conductivity,
ductility, and vibration resistance. Tin whiskering was discovered in the 1960s at
Bell Telephone in switching centers. Cadmium whiskers were found in radio
equipment in WW II.
Still more misstatements:
"“People have done a lot of work developing mitigation strategies such as
evaluating lead-free finishes that are less of a problem,” said Brady. “Plenty
of people are spending their careers on this topic.” These efforts have met
with success, but they tend to be expensive."
There is NO, repeat, NO lead free alloy that eliminates tin whiskering. Use
3% lead if you want to suppress whiskering.
Read the materials at the NASA website (http://nepp.nasa.gov/WHISKER/) - the
truth shall set you free (but it will scare the hell out of you).
Sincerely,
Bob Landman, President
Senior Member, IEEE PES, Reliability Society
H&L Instruments, LLC
Electro-Optics for Industry & Science
34 Post Road, PO Box 580
North Hampton, NH 03862-0580
(tel) 603-964-1818 (fax) 603-964-8881
www.hlinstruments.com
-----Original Message-----
From: Leadfree [mailto:[log in to unmask]] On Behalf Of Joe Fjelstad
Sent: Monday, January 26, 2009 6:36 PM
To: [log in to unmask]
Subject: [LF] link to EDN article of possible interest (EOM)
http://www.edn.com/article/CA6630671.html?nid=3351&rid=1549644147
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