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<tt>My fellow hams:<br>
<br>
Don't be so fast to replace what works. Another case of a law to
replace or reduce something before the technology is there to provide a
solution.<br>
<br>
Take a read about growing "tin whiskers" and lead free solder. Big
problem in RoHS circuits. And it don't take long to show up.<br>
<br>
"There is electrical risk posed by the other major component of solder,
tin. For reasons that remain somewhat obscure, tin used in electronic
devices can form what are called "<a
href="http://nepp.nasa.gov/whisker/">tin whiskers</a>,"
thin filaments of the metal up to 10mm long that sprout from surfaces
covered in the metal. Although the causes of the whiskers are obscure,
the consequences aren't: whiskers that bridge two conducting areas can
cause short circuits, causing erratic behavior or ultimately destroying
the equipment. NASA <a
href="http://nepp.nasa.gov/whisker/failures/index.htm">maintains a list</a>
of various military, orbital, and medical failures that have been
attributed to tin whiskers. Presumably, many failures in equipment that
is not significant enough to warrant a post-failure analysis are also
the product of tin whiskers."<br>
</tt><tt><br>
<br>
Notice how manufacturers are keeping quiet about this problem. In
some electronics it will take a while and then one day, smoke. Won't
be any rigs of today working say in 30 years like an old Drake TR4 does
today. I won't be buying anything lead free until the problem has been
solved for some time. <br>
<br>
Your millage may vary.<br>
<br>
Shanon KA8SPW<br>
<br>
<br>
Sites from the text above:<br>
<br>
"Tin Whiskers" <a class="moz-txt-link-freetext" href="http://nepp.nasa.gov/whisker/">http://nepp.nasa.gov/whisker/</a><br>
<br>
"NASA Maintains a list" <a class="moz-txt-link-freetext" href="http://nepp.nasa.gov/whisker/failures/index.htm">http://nepp.nasa.gov/whisker/failures/index.htm</a><br>
<br>
The article bellow has pictures with time taken to grow the whiskers in
different enviroments. <br>
<p style="margin: 0pt; line-height: 100%; text-indent: 0pt;"
align="left"><font size="3"><b>July 2008</b> </font>- Tin whiskers on
<u><span style="font-size: 12pt; font-family: Arial;"><i style=""><b
style="">Sn-3.8Ag-0.7Cu-1.0Ce/Er/Y </b></i><b
style="font-size: 12pt; font-family: Arial;"><i
style="font-size: 12pt; font-family: Arial;">S</i></b><b style=""><i
style="">older </i></b><i style="font-size: 12pt; font-family: Arial;"><b
style="font-size: 12pt; font-family: Arial;">J</b></i><b style=""><i
style="">oints</i></b></span></u> </p>
<!--mstheme--></tt><!--msthemelist--><!--msthemelist-->
<table border="0" cellpadding="0" cellspacing="0" width="100%">
<tbody>
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<td valign="baseline" width="42"><tt><img
src="cid:part1.09060706.09080301@sbcglobal.net" height="12" hspace="15"
width="12"></tt></td>
<td valign="top" width="100%"><!--mstheme--><tt> </tt>
<p style="margin: 0pt; line-height: 100%; text-indent: 0pt;"
align="left"><tt><span style=""><font size="2"><a
href="http://nepp.nasa.gov/whisker/other_whisker/SAC/2008-Hao-whiskers-SAC-Ce-Er-Y-solder.pdf"><b
style="">"</b></a><a
href="http://nepp.nasa.gov/whisker/other_whisker/SAC/index.htm"><b
style="">Tin Whiskers with Special Morphology<o:p> </o:p> </b><b
style="">"</b></a>, H. Hao, Y. Shi, Beijing University of Technology,
July 2008</font></span></tt></p>
</td>
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</table>
<tt> <a class="moz-txt-link-freetext" href="http://nepp.nasa.gov/whisker/other_whisker/SAC/index.htm">http://nepp.nasa.gov/whisker/other_whisker/SAC/index.htm</a><br>
<br>
</tt><br>
<br>
Bernard Tyers wrote:
<blockquote cite="mid:85B200CB-C2EE-4817-8FFC-F6461D2C76F9@ei8fdb.org"
type="cite"><br>
On 13 Oct 2008, at 07:29, Arno Verhoeven (PE1ICQ) wrote:
<br>
<br>
<blockquote type="cite"><br>
and believe it or not... China has come up with their own set of RoHS
<br>
requirements.
<br>
<br>
<a class="moz-txt-link-freetext" href="http://www.chinarohs.com/">http://www.chinarohs.com/</a>
<br>
</blockquote>
<br>
<br>
"It's not Just Another RoHS. It's CHINA RoHS!"
<br>
<br>
This is a joke? Yes? I wonder if they will have a RoHS rating for
Bindeez beads..
<br>
<br>
I, for one, am glad that the EU (one of the good things they have done
recently) are removing Pb from solder. The one time I had to get myself
near a large scale soldering/manufacturing station it wasn't pleasant.
And I was there only for a few weeks.
<br>
<br>
Now, if we can make some head way on other poisonous chemicals
(mercury, PVCs, flame retardents) it would be even better.
<br>
<br>
regards and 73,
<br>
bernard/ei8fdb<br>
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