Well, if I may address Ron's concern (who first posted on Gold).
If I remember correctly it was originally stated that the boards had 20-30
u" (0.51 to 0.76 um) of gold plated on Ni. That sounds still solderable for
common application. If you are in a rush, and are applying at least 4 mil of
solderpaste, you could most likely use these as is. I would very STRONGLY
suggest that you send a corrective action to your bare board supplier for
any future shipment. Keep good documentation of all corrective actions
posted with a vendor.
If you cannot use these for reason unknown to us... Good luck, I strongly
suggest that you avoid using the stripping or any other method, this would
most likely make the boards unreliable.
Franklin, if you ever use cyanide there is a weak warning bitter almond
smell before you get poisoned to the point of unconsciousness, be careful
you rapidly get used to the smell and will not notice rising gas
concentration. Also speaking from experience, I got out early after closing
the sash on the fume hood while holding my breath, got the worst headache of
my life, but all in all, Ok. Cyanide should only be used with proper vapour
extraction at the source.
Alain Savard, B.Sc.
Chemical Process Analyst
CAE Electronics Ltd.
e-mail: [log in to unmask]
-----Original Message-----
From: Franklin Asbell [mailto:[log in to unmask]]
Sent: March 15, 2000 8:01 PM
To: [log in to unmask]
Subject: [TN] Gold Removal
Cyanide in and of itself won't remove gold, it's a lot more detailed than
that, and then controlling how much is removed is almost impossible.
Speaking from experience, you won't even smell almonds, you might see a
humid cloud drifting slowly away from the tank, and the next thing you'll
see is the ER doctor telling you things will be just fine.
30 microinches of Gold won't affect solderability any different then 10
microinches. What it might affect depending on your application is the
electrical properties.
If 30 microinches is simply intolerable then buff the gold tabs or pads down
to what you believe to be a tolerable level, unless you have access to an
XRF or similar device though, you won't know how far you've gone.
Sure, reject it all back to the fabricator, have them restart the job, put
everything on a back burner, or better yet, find another supplier, resubmit
gerber, have them do it, of course you'll want to survey them first, gotta
remember to schedule that before we give them the order.
~...hmmmm, wondering if I'm being too facetious, nah, not with this group,
they can appreciate the humor in this....grinning~
Franklin
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