Hi Everyone,

I am currently attempting a Cu electroplating on PCBs. Patterns were firstly
etched from the Cu foil onto the dielectrics. A layer of Ag was sputtered onto
the subtrate and then the 2nd litho. What I am trying to do is to plating Cu
into the photoresist trenches (100~200um wide). But the Ag layer seemed to be
etched away before the copper was plated. I thickened the Ag layer by 2 or 3
times, the Cu plating started but the film was quite non-uniform. My guess is
the potential dropped too fast to plate the Cu in some areas but I already have
the cathode connect to all the edges of the PCB so supposely it shouldn't be an
issue.

Anyway, does anyone have any suggestions on how to improve the uniformity of the
Cu plating onto thin Ag layer? Should I increase the current density?

Appreciate your help.

Regards,

Mingke Xiong
AEM, Inc.
6610 Cobra Way
San Diego, CA 92121, USA
858-481-0210 (1660)
www.aem-usa.com