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Wed, 1 Apr 1998 09:21:03 -0500 |
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Mickey,
I've asked this question before (about 9 months ago) with no responses
at that time. I'm not so sure galvanic corrosion would be an issue. My
concern would be intermetallic formation which would lead to higher
resistance. I don't know if this increase would be high enough to be
detected or cause a problem. I was wondering about this because someone
was looking into using a Ni/Au board finish with press fit connectors.
The big issue here was the higher insertion force since solder to solder
provides a nice slippery interface.
Paul Terranova
Analytical and Environmental Test Services Lab
Worldwide Module Components Group
Digital Equipment Corp
200 Forest Street
Mail Stop: MRO3-1/D2
Marlboro, MA 01752-3085
' Phone: (508)467-3109
* Fax: (508)467-6796
* Email: [log in to unmask]
-----Original Message-----
From: Michael Weiner [SMTP:[log in to unmask]]
Sent: Wednesday, April 01, 1998 7:36 AM
To: [log in to unmask]
Subject: [TN] (assy)press-fit connectors
Dwight,
May I join in on this issue with another aspect.
We assemble back planes and daughter boards with press fit type
connectors for
years now with very good results.
As you have mentioned, we too consult the bible (GR-78-CORE).
We always specify solder finish for the connector tails for
use in
our pwb's,
which are hasl finished.
Mating section is gold on both male and female.
Recently, a distinguished (no names ) connectors manufacturer
has
announced that
a particular part no. is available with gold finish only.
Promising
us that even though
there is potential difference between gold and tin (lead):
"this will not result in a galvanic corrosion"
The Bellcore does not address this issue of galvanic
intermetal
compatibility
with regard to press -fit .
Is there any test data to prove that galvanic couples do not
pose
any problem in
press fit application for telecom environment.
BTW the potential difference between gold and solder according
to
mil-f-14072
is 0.65 volt.
Any help will be appreciated.
Mickey
--
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
michael weiner Tadiran Telecommunications Ltd
tel: 972-3-9262937 fax: 972-3-9261803
e-mail: [log in to unmask]
homepage http://www.tadirantele.com/
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