Re: Cynowe wasy (whiskers)

> W trakcie czynienia wszystkiego ekologicznym postanowiono
> zastapic stop lutowniczy zawierajacy Pb stopem bezolowiowym.
> Jeden z problemow polegal na dziwnym zachowaniu
> pocynowanych czysta cyna koncowek elementow: rosly z nich
> wasy o dlugosci nawet 0.25 mm (pod mikroskopem wygladaja jak
> kielki nasion), a wiec dlugosc tych wasow byla wystarczajaca do
> zwarcia sasiednich wyprowadzen w ukladach scalonych. Jaki jest
> mechanizm "kielkowania" cyny?
>
> Pozdrawiam,
> Pawel

Przypominam problem z cynowymi wasami, nowe zdjecia i filmy:
http://nepp.nasa.gov/whisker/
http://nepp.nasa.gov/whisker/video/index.html

Moga miec nawet 1 cm dlugosci.

Rosniecie tych metalowych wasow jest dosc fascynujace, szczegolnie jak
sie spojrzy na mikroskopowe zdjecia:
http://www.sigcon.com/images/news/v10_01a.jpg
http://www.sigcon.com/Pubs/news/10_01A.htm

Nie tylko cyna je tworzy:
http://nepp.nasa.gov/whisker/other_whisker/index.htm
http://nepp.nasa.gov/whisker/photos/floor_tile/index.html

Znowu UE podobnie jak z CFLami (zarowki fluorescencyjne z rtecia),
"chciala dobrze, a wyszlo jak zawsze":
http://www.sigcon.com/Pubs/news/10_01.htm

Swoja droga w w/w artykule jeszcze o "tradzie cynowym" zapomniano.

"Fortunately, military products get a special exemption from RoHS.
They can use as much lead as they want. The exemption was granted on
the basis that the E.U. commission understands quite clearly that no
suitably reliable substitute for lead-based solders has yet been
found.

Great, so the E.U. admits there is no reliable substitute. Yet, they
require use of a substitute.

Is this some kind of plan to increase sales of electronic gadgets? Is
this a way to make sure that products fail quickly, so consumers have
to buy more?

We won't know for several years how severe the problem will ultimately
become, but what we do know is that many tin-whisker failures have
already happened, and more will happen in the future. "

Wasy cynowe juz spowodwaly awarie reaktora atomowego:
"Millstone Nuclear Generating Station — A single tin whisker created a
bridge (short circuit) between a diode and the output trace on a
circuit card, causing a partial reactor shutdown. P. Daddona,
"Reactor Shutdown: Dominion Learns Big Lesson from a Tiny Tin
Whisker", The Day (New London, CT), July 4, 2005
http://nepp.nasa.gov/whisker/reference/tech_papers/2005-dadonna-nuclear-reactor-shutdown.pdf
"

Tin (and Other Metal) Whisker Induced Failures:
http://nepp.nasa.gov/whisker/failures/
"Engineers are now just beginning to recognize a lot of past failures
as having been caused by tin whiskers."
http://www.sigcon.com/Pubs/news/10_01.htm
Received on Tue Nov 9 15:56:11 2010