Hi Erik/Dave -
     
     I suggest that an ion chromatography (IC) test be conducted to see if 
     the chlorine was absorbed into the soldermask or other surfaces of the 
     circuit assemblies. There is a large body of data that shows that 
     chlorine will cause reliability problems in terms of corrosion 
     phenomena. There may be a better test than IC to determine if chlorine 
     could be absorbed and/or be mobile - maybe Doug Pauls or Susan 
     Mansilla can suggest a test method.
     
     
     Dave Hillman
     Rockwell Collins
     [log in to unmask]


______________________________ Reply Separator _________________________________
Subject: Chlorine damage to electronics (fwd)
Author:  [log in to unmask] at ccmgw1
Date:    6/16/97 1:56 PM


Can anyone on TechNet help?
     
Thanks
Dave Bergman, IPC
     
---------- Forwarded message ---------- 
Date: Mon, 16 Jun 1997 10:47:23 +0000
From: Erik Ievins <[log in to unmask]> 
To: Dave Bergman <[log in to unmask]>
Subject: Chlorine damage to electronics
     
Hi there.  This is additional information for the voicemail 
message I left you earlier this morning.  Can you help me 
get this question to the right person?  I would greatly 
appreciate it.
     
We've got a situation where electronic circuit boards were 
exposed to dry chlorine gas for several hours.  Many of
the IC chips have failed, but other than a few exposed ends 
of copper wire turning brown, there is no visible evidence 
of corrosion on the boards.  I know that there would likely 
have been significant evidence if the ambient humidity had 
been higher, due to formation of hydrochloric acid.
     
Can chlorine gas molecules penetrate the plastic IC housings 
and attack the tiny, gold connecting wires inside the chips? 
Or is there some other explanation?
     
Thanks very much!
______________________________________________________________ 
Erik L. Ievins, technical consultant.
LWG, Inc.  (847)559-3008 ext 276
     
Smile, the world will wonder what you're up to.   :)
     
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