Hi Yehuda!
Here's an article discussing OSP's and includes discussion about OSP and
press-fit interconnects, which essentially is bare copper. Go to:
http://img.cmpnet.com/assembly/db_area/archives/top100/pdf/9905enthone.pdf
Bare copper is not a problem, the copper will oxidise to a certain point, and
the oxidation acts as a barrier to prevent further oxidation...you can't
solder to oxidized copper, but it won't deteriorate further. There are
environments that could cause problems though (salty, humid, hot,
environments for example), but then you would want to conformally these
assemblies anyway, whether OSP coated or otherwise finished...
One of the best examples of copper robustness is the statue of liberty,
entirely made of copper, withstood the elements (acid rain included) for
100-years before requiring restoration. Another example is the telegraph
lines that were strung across the US in the 1800's...non-insulated copper
wire that survive even today...
-Steve Gregory-
<< Hi All,
I am sending this question again, in case somebody does have a relevant
input. I suppose that over time, this issue must have been discussed or
examined in the industry or in the military standard committees.
Thanks,
Yehuda
----- Original Message -----
From: Yehuda Weisz
To: IPC TechNet
Sent: Sunday, April 15, 2001 9:26 PM
Subject: Reliability of exposed copper
Hi Technetters,
I hope that you got over Easter and its bunnies easily and I would like to
ask a small question.
Does anyone of you remember any study regarding the reliability of exposed
copper (such as in a unprotected PCB - no soldermask and no solder) in
different environmental conditions?
Best regards,
Yehuda
>>
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