Hi Kathy

There are several possibilities. One scheme that has been reported is to use
a screen printable solderable coating as the etch resist, normally organic
in nature (e.g. imidazole). Another is pattern plating copper onto to a very
thin clad substrate and also use differential etch approach but with
standard chemistries and no manipulation. You may also wish to look up the
work of Norvell Nelson (formerly of PSI-Star a defunct PCB manufacturer in
the Bay Area) Some of his patents describe novel etching techniques and
chemistries.

Good luck in your efforts.
J.Fjelstad

At 12:16 PM 3/19/97 -0800, you wrote:
>
>Does anyone have any information on this issue for this graduate student?
>Please reply directly to [log in to unmask]
>
>Thanks!
>
> ----------
>From:   Cathy Chang[SMTP:[log in to unmask]]
>Sent:   Wednesday, March 05, 1997 8:44 PM
>To:     [log in to unmask]
>Subject:        elimination of etch-resist
>
>
>I'm currently working on my graduate research which involves evaluation of
>lead-free P2 measures (conductive adhesive, tin-only plating and LLNL's
>proposed technology) to be used in place of etch-resist or soldering for
>printed circuit board production.
>
>LLNL is currently developing an improved etching process
>that will eliminate the use of etch-resist by employing differential etching
>based on manipulation of copper grain chemistry. When Dr. Duke and I visited
>one of the PWB facilities for a tour, we were told that Japanese PWB
>industry is (or has) working on similar technology which eliminates the use
>of etch-resist in PWB manufacture.  We are trying to get our hands on
>literature that might give us more info. on the kinds of technology that
>falls into this category (since we don't know exactly what this technology
>is at the present time).
>
>So, if anyone has any insights on the issue, I'd love
>to hear about them.
>
>Thank you
>
>Cathy Chang
>e.mail: [log in to unmask]
>
>**************************************************************************
>* The mail list is provided as a service by IPC using SmartList v3.05    *
>**************************************************************************
>* To unsubscribe from this list at any time, send a message to:          *
>* [log in to unmask] with <subject: unsubscribe> and no text. *
>**************************************************************************
>* If you are having a problem with the ComplianceNet forum, please call  *
>* Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask]     *
>**************************************************************************
>
>
>
>
>***************************************************************************
>* TechNet mail list is provided as a service by IPC using SmartList v3.05 *
>***************************************************************************
>* To subscribe/unsubscribe send a message <to: [log in to unmask]>   *
>* with <subject: subscribe/unsubscribe> and no text in the body.          *
>***************************************************************************
>* If you are having a problem with the IPC TechNet forum please contact   *
>* Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask]      *
>***************************************************************************
>
>
>
*************************************************************************
    _/_/_/_/  /__  __/ / ____/ / ___/ / ___/  / ___/  / __  /    / \  
   _/_/_/_/     / /   /       /___   /___    /       / __  /    / _ \
  _/_/_/_/     / /   / __/       / /    /   / __/   / / \ \    / ___ \
 _/_/_/_/     /_/   /_____/  /____/ /____/ /_____/ /_/   \_\  /_/   \_\

 ...System Building Blocks for the Next Generation of Electronics
 
 3099 Orchard Drive
 San Jose, CA 95134
 Phone 408 894-0700
 Fax   408 894-0768

***************************************************************************
* TechNet mail list is provided as a service by IPC using SmartList v3.05 *
***************************************************************************
* To subscribe/unsubscribe send a message <to: [log in to unmask]>   *
* with <subject: subscribe/unsubscribe> and no text in the body.          *
***************************************************************************
* If you are having a problem with the IPC TechNet forum please contact   *
* Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask]      *
***************************************************************************