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Full-name: Syrtek
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Date: Thu, 27 Jan 2000 16:21:38 EST
Subject: TEMPERATURE EFFECTS ON ACID COPPER PLATING
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Dear Net,

We've been having a great deal of trouble with smutting in low Asf areas of
our
Pcb's since the cold snap. Our acid copper plating bath is LeaRonal's PCM
Plus.
The bath is room temp.. Last week the bath was at 78 F, this week it is at
74F.
The other big factor is the preplate line. The rinses are normally heated to
85-88 F.
A malfunction caused the temps to be at 58 F. The acid dip must have been
affected
by the cold panels because its room temp is now 64 F. We started applying
35-40
Asf initially to avoid low current area smutting. It helps. We just
discovered the rinse
temp prob. and bath temp variation. Could someone explain cold panel issues
and
the mechanism of this smutting? The panels entered the tank at 64 F. Why
don't
they all smut? Only about 20-30% smut. I adjusted the rectifier as I loaded
each
panel. We use direct metallization-Pd vanillin-.
I can't recreate in the hull cell. Test panels look good.
Thanks,
Julie Dixon