Frank,
You dont say what type of voids you are getting, wedge,
metallisation, etch out? or what the aspect ratio is on the product you are
getting problems on, is the defect more prevalent on products that are
thick, or is it on all panel thicknesses?
I guess you have confirmed that all holes are free from debris
before pattern plate (real pain in the neck this one) Include a close look
at rinse solutions, could be that rinsing post resist develop is not
sufficiently cleaning out residues, and you just have a none platable layer
in the bore of the hole.
Is there any pattern to the location of those voids that you are
getting, edge of panels, have the panels been reworked? we have found that
vibration is critical, especially on high aspect ratio stuff and this is
likely to vary across the flight bar in the plating lines. when it occurs,
have the panels all been in the same plating tank, or common sump, could be
related to a contaminated sump.
I guess we would need pictures to help as much as possible, unless the
plating gurus come up with something quick
Good luck
Roger
-----Original Message-----
From: Frank Davies < [log in to unmask]
<mailto:[log in to unmask]> >
To: IPC < [log in to unmask] <mailto:[log in to unmask]> >
Date: Wednesday, November 15, 2000 11:25 AM
Subject: voiding
Hello out there:
This message of help could have been summited by another but I still need
some advice or opinion, Thanks. We are experiencing problems with voiding in
small holes (not too small .35mm 0.014) and some larger holes at random
times. We use a Direct Metalization process for hole prep. with a palladium
base. I realize the problem of bubbles and foreign objects in holes and
such after drill (high pressure rinse after deburr and vibrate on line) but
we are still getting a panel or two at random on too often occasions. We
have the line checked daily to be sure we are in spec. chemically and
mechanically, the voids are still happening too often here as of late. Is
there anyone out there experiencing this problem with the direct
metalization process? I did some panels with panel plate and direct metal
plate side by side and couldn't create the problem. Any ideas or help would
sure be appriciated.
Thanks in advance
Frank
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