At 09:38 AM 4/18/00 -0400, you wrote:
>Good Morning All,
>
>Today, I am tasked with gathering some research info on primary imaging
>of double treat multilayer material.
>
>We have experienced some staining and lock on situations in the past and
>I am looking for any input from board fabricators with any similar
>history.
>I understand that some of the newer treatments (Zbz?) have a similar
>appearance.  Appreciate all info, from TechNet or direct.
>
>Anne Ledger
>Process Engineer
>EMDS, Inc.
>[log in to unmask]

Hi Anne,

         I spent quite a bit of time finding the best chemistry and overall
procedure for processing doubletreat laminates.  Areas I had to come to
terms with were:

         * Fingerprints - overall handling
         * Resist lamination parameters
         * Resist choice
         * Developing - particularly rinse characteristics
         * Stripping - the most challenging process in a successful
doubletreat program

         I found no shortcuts.  Just basic process engineering.  Such as
looking very closely at the resist laminator to make sure the exit
temperature is ALWAYS at optimum for doubletreat.  Training personnel in
handling procedures.  Making sure I had adequate rinsing in the developer
and that the pH of the waters were reasonably close to neutral.

         The biggest issue I faced was the stripper.  Both from a machinery
and a chemical standpoint.  This often overlooked manufacturing process
will bite you hard when processing doubletreat.  Finding the right
chemistry to match your machinery is important.  I don't know if you're
using filterable or dissolvable chemistry so I can't make any real
suggestions regarding your process.  But I can say that you'll need to do
plenty of testing in order to find the right blend for your equipment and
doubletreat.  And clearly, your machine's ability to provide adequate
impingement AND water spray is very important.  Look very closely at your
machinery.  A lot of shops neglect this system.  Doubletreat won't tolerate
the neglect.

         You may want to ask your laminate supplier to give you names and
numbers of other manufacturers using their doubletreat.  Call these guys
and talk to them about the problems you've seen.  They've seen the same
thing and will be much more able to give you names of dry films and resist
strippers over the phone than on this forum.

         Doubletreat is a good product when you learn how to use it.  It's
worth the effort.

Good luck,

Mark Mazzoli

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