Francis: You have received a lot of good input on your question and  will
have plenty of things to go look at.
Let me approach from a little different angle. Your original issue was a
variation of 150 u" from panel to panel and if that was acceptable i.e. "did
I do anything wrong ?". I assume you are finding this at pattern plate. If
that is the case and you are plating an average of 1.5 mils of copper; then
you are at 1.5 mils +/- 5%.
Whether you are using electronic or optical/X-section measurement +/- 5% is
about the limit of their accuracy. So there is nothing wrong with the
numbers you are seeing IF you are measuring the same style panel in the same
place on the panel, plated at the same cathode location with the same bath
and rack. I don't think you will find an acid copper plating supplier in the
world that would guarantee less than +/- 5%. But you know what the boss
says; you can always do better. So go over all the previous posting
suggestions and make sure everything is tuned in correctly. Hint: proper
electrical connections, racks/rectifier/anodes and good anode maintenance
will  give you the biggest return on good distribution if your bath
chemistry is in proper balance.

Regards

Michael Barmuta

Staff Engineer

Fluke Corp.

Everett WA.

425-356-6076
                                -----Original Message-----  From: Francis
Lai [mailto:[log in to unmask]]
Sent: Sunday, July 04, 1999 11:25 AM
To: [log in to unmask]
Subject: [TN] Cu thickness varies from panel to panel


Recently, I have found that Cu thickness plated onto panels may vary uo
to 150 u inches from one panel to another under the same conditions and
current and in the same bath.
Did I do anything wrong? I am using a Macdermid acid plating bath 9241.

My e-mail : [log in to unmask]

THANKS!!!!!!!!

Francis