Hi Antonio,
The leads are brazed on this ceramic module, which means using of a high
temperature brazing material. The high temperature combined with the
colour makes me think of purple plague. Which means that gold and tin
has formed an intermetallic with that name, purple plague. If you
magnify the picture in shop, you can see that the purple is found on
nearly all the leads, close to the ceramic body. IF this is the fact, I
would not rely on such components, but reject them.
Another possibility is that purple plague has been created cause you
have run excessive current through the leads, but I find that scenario
less probable.
Before doing anything, I suggest you mold the part in acrylic or similar
plastic, grind until you reach a region near the ceramic body, polish
and study the cross section in a metallurgical microscope, even make
study in SEM.
I would also take another sample and make a bending test on the leads to
see what the brazing area is like. You bend 90 degrees in one direction,
bend back to zero, then another bend minus 90 degrees and back to zero.
Totally 180 degrees. If the leads fulfills that test without cracking or
loss of terminals, they are OK talking mechanical strength.
Ingemar Hernefjord
Ericsson Microwave Systems
Last working day, then holidays!
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of antonio
Sent: den 6 juli 2006 15:46
To: [log in to unmask]
Subject: [TN] Corrosion on Gold plating
Please I have a lot of components with corrosion on terminals gold
plating. Please see picture. Could anyone suggest an acelerating test to
evaluate que problem?
thanks a lot
Antonio Souza
Brazil
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