[Premium-Rx] lead free solder tin whiskers

[Gary Geissinger]

If you exercise the circuits on a regular basis even with CMOS you stand a good chance of clearing the shorts.  The tips of the whiskers are microscopic. 

But if you don't run the circuits for a long time the shorts won't clear even with significant current.  Some geosynchronous satellites were lost this way a few years ago.

This is an argument against "cold sparing".  It reminds of issues with electrolytic capacitors.  It pays to "fire up the boat anchors" every once in a while.

Gary WA0SPM

-----------------------------------
Sent from my BlackBerry Wireless Handheld

----- Original Message -----
From: premium-rx-bounces at mailman.qth.net <premium-rx-bounces at mailman.qth.net>
To: 'Henry A. Kolesnik' <kolesnik at sbcglobal.net>; premium-rx at mailman.qth.net <premium-rx at mailman.qth.net>; 'Jan Skirrow' <jan at skirrow.org>
Sent: Mon Jul 23 13:15:53 2012
Subject: Re: [Premium-Rx] lead free solder tin whiskers

CMOS wouldn't.

Ed Tanton
 
website: http://www.n4xy.com 
 
All emails <IN> & <OUT> checked by 
Norton AntiVirus with AutoProtect 

--------------------------------------------------
Wag more / Bark less
--------------------------------------------------

-----Original Message-----
From: premium-rx-bounces at mailman.qth.net
[mailto:premium-rx-bounces at mailman.qth.net] On Behalf Of Henry A. Kolesnik
Sent: Monday, July 23, 2012 3:12 PM
To: premium-rx at mailman.qth.net; Jan Skirrow
Subject: Re: [Premium-Rx] lead free solder tin whiskers

I was amazed at how thin the whiskers are and it seems like most circuits
would clear them out unless specifically designed not to.  Are Toyota
circuits that low current?


--- On Mon, 7/23/12, Jan Skirrow <jan at skirrow.org> wrote:


From: Jan Skirrow <jan at skirrow.org>
Subject: Re: [Premium-Rx] lead free solder tin whiskers
To: premium-rx at mailman.qth.net
Date: Monday, July 23, 2012, 1:36 PM


These are very interesting articles. The problem of maintaining the current
crop of premium radios is going to become very much more difficult as the
years go by. Enjoy them now! What is perhaps sad, is that the whole
changeover to Pb free solders is based on misinformation about Pb leaching.
Ah well ....


On 7/22/2012 2:14 PM, M Peraaho wrote:
> Lead free solder problems in electronics, automobiles, etc.
>
> http://nepp.nasa.gov/whisker/reference/tech_papers/2011-NASA-GSFC-whis
> ker-failure-app-sensor.pdf
>
> http://nepp.nasa.gov/whisker/reference/tech_papers/2011-kostic-Pb-free
> .pdf ______________________________________________________________
> Premium-Rx mailing list
> Home: http://mailman.qth.net/mailman/listinfo/premium-rx
> Help Page: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Premium-Rx at mailman.qth.net Help Contact eMail:  
> paul at 8zo.com Home Page:  http://www.premium-rx.org/
>
>
>


______________________________________________________________
Premium-Rx mailing list
Home: http://mailman.qth.net/mailman/listinfo/premium-rx
Help Page: http://mailman.qth.net/mmfaq.htm
Post: mailto:Premium-Rx at mailman.qth.net
Help Contact eMail:  paul at 8zo.com
Home Page:  http://www.premium-rx.org/
______________________________________________________________
Premium-Rx mailing list
Home: http://mailman.qth.net/mailman/listinfo/premium-rx
Help Page: http://mailman.qth.net/mmfaq.htm
Post: mailto:Premium-Rx at mailman.qth.net
Help Contact eMail:  paul at 8zo.com
Home Page:  http://www.premium-rx.org/

______________________________________________________________
Premium-Rx mailing list
Home: http://mailman.qth.net/mailman/listinfo/premium-rx
Help Page: http://mailman.qth.net/mmfaq.htm
Post: mailto:Premium-Rx at mailman.qth.net
Help Contact eMail:  paul at 8zo.com
Home Page:  http://www.premium-rx.org/

This electronic communication and any attachments may contain confidential and proprietary 
information of DigitalGlobe, Inc. If you are not the intended recipient, or an agent or employee 
responsible for delivering this communication to the intended recipient, or if you have received 
this communication in error, please do not print, copy, retransmit, disseminate or 
otherwise use the information. Please indicate to the sender that you have received this 
communication in error, and delete the copy you received. DigitalGlobe reserves the 
right to monitor any electronic communication sent or received by its employees, agents 
or representatives.