Homebrew PCBs

Hexavalent chromium, good point.
Thanks for the references.

--- In Homebrew_PCBs@yahoogroups.com, Volkan Sahin <v_sahin@...> wrote:
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> I've used similar formula before.  It is chromate based and not environmental friendly. Because of that I started to use dry-film resist. Chromate based resists are proven and you can get very high resolutions. 
> Note: Check Message #26532 or search "Photo Resist Gelatin Bicromate Process" in the group archive. 
> Volkan 
> --- On Mon, 3/7/11, mtuchelt <mtuchelt@...> wrote:
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> From: mtuchelt <mtuchelt@...>
> Subject: [Homebrew_PCBs] Simple Photoresist Recipe?
> To: Homebrew_PCBs@yahoogroups.com
> Date: Monday, March 7, 2011, 7:38 PM
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>       Hi All
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> I posted an interesting patent on a photo resist process. The patent describes applying a non-sensitized (very simple) polymer coating to the pwb, drying and storing. When needed, the board is sensitized by spraying it with the photo-initiator, drying and exposing. 
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> The developer is water, the stripper is caustic.
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> Anyone have any experience with or used this ?
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> Comments from the chemists among us on the usefulness of this info would be much appreciated.
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