Practically makes me abandon my attempt to direct resist ....
Mike KC7NOA
To:
Homebrew_PCBs@yahoogroups.comFrom:
randy_hunt960@...Date: Sat, 17 Dec 2011 19:28:10 +0000
Subject: [Homebrew_PCBs] Re: Anyone use a Scotch TL901 Laminator?
Thank you for the info. . .
Randy
--- In Homebrew_PCBs@yahoogroups.com, "Ray" <rcbuckiii@...> wrote:
>
>
>
> --- In Homebrew_PCBs@yahoogroups.com, "randy_hunt960" <randy_hunt960@> wrote:
> >
> > Could you provide more info on the "Dry Film"?
> >
> > thanks,
> > Randy
>
> Randy,
>
> Dry Film is a Negative acting film that is applied to the copper clad. When you print the image on clear film you have to print it in reverse. The areas that are clear is what remains on the board when you develop it.
>
> The film is a fairly thick (1-2 mils) plastic like coating so it is much less likely to break down in the etching process. Lines down to 8 mils are a piece of cake. Dry film is what all the professional PCB manufacturers use to make boards. You develop it with Sodium Carbonate. Arm & Hammer Super Washing Soda works well.
>
> These links will give you an idea of how it works:
> http://www.trianglecircuits.com/imaging-process.html
> http://members.optusnet.com.au/eseychell/PCB/photoresist/Wet_Lamination_of_Photoresist_for_Hobbyists.pdf
> http://www.voodooengineering.com/index.php/pcbprocess/preparation/77-dry-film-lamination
>
> The 2nd link shows how to apply it without heat but I've never seen it done that way.
>
> I used it for years back in the late 80's early 90's then switched to using presensitized positive boards from Circuit Specialists. Now I'm switching back to the negative process. It requires less of a darkroom environment, the film is more rugged, and the cost is about half of the presensitized positive boards. According to the manufacturer the shelf life is 6 months for the film. But I have used film that is over a year old with no problems.
>
> I purchased the dry film from Larry on this forum. See post #28833 for details and contact him if you are interested in trying the process. His price is better than the prices from China on Ebay and he is very helpful.
>
> Ray
>
[Non-text portions of this message have been removed]