Hi folks! Just an FYI. The use of stranded silver coated wire has the
potential of causing corrosion issues. As Rainer and Bogert both pointed
out, silver coated wire has been successfully used in high performance
electronics for many years without issues. However, there are documented
instances of specific use environments (e.g. direct marine exposure) where
using silver coated wire resulted in corrosion problems. Every material is
not suited for every use environment - the trick is to understand your use
environment and how protected/shielded your electronic product is from that
use environment.

Dave Hillman
Rockwell Collins
[log in to unmask]



March 11, 2006

We also have used stranded silver coated wire for years with no known
problem.  Last year, I tried to convince the IPC folks responsible for IPC
7711/7721 to either delete their statement in the document not to use
silver coated wire, or otherwise provide the technical basis for the
statement.  They did not provide any info and left the caution in the IPC
document.

I could not open the hyperlink address you gave in the e-mail.  Can you
please e-mail me the article?

[log in to unmask]<mailto:[log in to unmask]>


  I'm not sure what being lead-free has to do with corrosion, but here in
  the Space Product business virtually all of our hard wiring and cabling
  consists of silver plated copper wire.  It's been that way for 40 years
  and we have never seen or heard of any corrosion issue.  We also use
  solid wire with the same reliable results.  The only corrosion that I
  have ever heard of was called "Red Plague" in the early 1960's and was
  the result of fractures in too thin silver plating.  A galvanic reaction
  was set up between copper and silver at the fracture line that slowly
  consumed the copper.  This was resolved by the wire industry by
  increasing the thickness of silver plating.  This corrosion is extremely
  rare!  Here is a link to a report on the subject.
  http://nepp.nasa.gov/docuploads/97164203-A4FB-479A-A075C918D51DD81E/ESA%<
http://nepp.nasa.gov/docuploads/97164203-A4FB-479A-A075C918D51DD81E/ESA>
  20Red%20Plague.pdf


  > Rainer G. Blomberg
  > Honeywell -Space Systems Clearwater
  > Staff Production Engineer
  (727) 539-5534


  All:



       We need to add a 30 AWG jumper wire to a lead-free assembly (Class
  II). IPC-A-610 says that silver plated stranded wire should not be used
  due to possible corrosion under certain conditions. Our thoughts are
  that this (corrosion possibility) is unique to stranded wire. Would
  silver plated solid wire be an alternative? Any input would be
  appreciated. Thanks.


  Regards,

  Steve Vargas

  Sr. Mfg. Engineer

  Polaris Contract Mfg. Inc.

  [log in to unmask]<mailto:[log in to unmask]>

  508-748-3399 ext.192

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