First rule out the electroless line.  Dummy plate some panels (electroless)
then run them through your etcher. If they etch cleanly, move to the next
step in the process.

One of the other posts to your question mentioned lock in.  Thats where I'd
put my money.  Another possibility though,  based on your description that
it appears to be spattered, is under developed resist redepositing on the
panel in the developer.  Underdeveloped resist is like goo that will deposit
randomly across a panel.  You can see it but you really have to be looking
for it.  It's pretty much colorless.

To track it down I'd run some dummy panels, like I suggested for the
electroless line.  Laminate some panels; allow them to sit for the maximum
amount of time a laminated panel will sit in your yellow room, develop it
and etch it.  I'd also run an unlaminated panel through the developer then
etch it.  If you are getting redeposited resist it will show up on the
unlaminated panel.

Good luck - hope this helps.

pete



>From: Rich Olsen <[log in to unmask]>
>Reply-To: TechNet E-Mail Forum <[log in to unmask]>,              Rich Olsen
><[log in to unmask]>
>To: [log in to unmask]
>Subject: [TN] Surface Contamination on Electroless Copper
>Date: Sat, 26 Mar 2005 10:45:49 -0700
>
>Hi,
>
>         Has anyone seen the following?
>         Surface contamination on top of electroless copper.
>         It prevents plating and subsequent etching.
>         It is both under the resist and in exposed areas during pattern
>plate and
>etch.
>         It is small on the order of a mil or two, but there can be lots of
>it.
>         It seems to be in streaks, a spattered appearance.
>
>thanks,
>Rich
>
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