In a message dated 99-06-04 18:08:29 EDT, [log in to unmask] writes:

<< PTH there are fluffy,
 small minute copper deposits around the drilled holes besides the
 electroless copper on the PTH walls.  >>

More information about the electroless bath and PTH line will be helpful in
solving your problem.  First I will give you some places to look, and then
ask for some process conditions in your line.

Possibly
1. You are really plating on something fibrous in your holes.  This could
come from backing board in drilling, deburring brush debris, or remote
possibility you have some sort of algae in a tank (rinse?) and this slime is
getting plated.  Certainly electroless over any of these will give nodules in
the hole and pits in pattern plating.  What do your holes look like under a
microscope after drilling and after deburring?   Do any of your tanks
(especially rinsees)  have a slimy feel (wear gloves) on the walls.  Most
process tanks are have so much chemical they won't support algae or bacteria,
but rinses might.

2. Your electroless bath may be extremely active and you are about to plate
out your tank.  Or, your tank has started plating out and you can see
hydrogen bubbles in the blue electroless solution even when there are no
boards in the tank.  Chemical consumption should be way more than data sheet.


3. Something else is causing an super active bath - is your temperature too
high?   Have you over added one of the components - especially formaldehye or
caustic?  Is the circulation or air agitation turned off?

Now for the information:

1. What has been the process control in the last couple of days - anything
unusual - plating rates, chemical consumptions, process changes, new laminate
types, etc.

2. What is your frequency of analysis - chemicals, plating rate, activation
line parameters?

3. How can I call you direct to help in solving your problem?   I think you
are in Canada by your address, but don't know your company.   I have
forwarded you e-mail to our Canadian sales/service people.   I know it's a
weekend, but I have a lot of phone numbers - I'm not the electroless expert,
just the first MacDermid person on TechNet tonight.

Denny Fritz
MacDermid, Inc. - US
765-647-5766
fax - 765-647-0312

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