Homebrew PCBs

Please do keep us informed if you find a suitable UV curing ink.
I agree it seems the most promising.

I would not mind putting the "wet" pcb under UV lamps for curing.

ST



On Sat, 7 May 2005 20:14:39 +0100, John Kent <moonshadow@...>  
wrote:

> Thank you for the reply, I found it very interesting.  As you say part of
> the answer is in cleaning or preparing the copper surface but most of my
> problems lay with the ink.  I got in contact with many ink manufacturers  
> and
> we had some rewarding discussions about this application.  It basically
> boils down to the choice between a solvent based ink or an UV cured ink.  
> The
> water solvent based inks I have tried so far, simply wash off in the acid
> bath. There can also be a problem with the solvent vaopurising and  
> cloggung
> the head. I came to the conclusion that a UV cured ink may be a possible  
> all
> round solution. These are actually resin based and offer a much more  
> durable
> printed image. UV inks are available that will cure in a fraction of a
> second. So it might be possible to mount a fibre bundle from a UV light
> source to just behind the print nozzles as a low mass light cure source.
>             Taking the idea one step further, it would also be possible  
> to
> print, graphics, flux as well as acid resist direct onto the board. This
> leads us onto conductive inks, which already exist.  They normally  
> require
> special for purpose heads, but seem to work well for most low power
> applications. I think for my own purposes a simple A5 flat bed printer,
> using UV cured ink would do the trick. Another advantage of UV ink is  
> that
> it does not dry in the nozzles as solvent ink does. I have seen  
> applications
> where multilayer boards have been produced using UV inks, with an  
> insulating
> ink between layers ... and all of this printed on a flexible substrata.
> Anyway who says we have to have a purpose substrata since we can print  
> onto
> anything!
>              It is possible to convert the older models of Cannon  
> printers
> into flat bed, I have one on the bench at the moment. Thanks again for  
> the
> reply. .
> John.
> ----- Original Message -----