Homebrew PCBs

Using silk screen emulsion,  it is worth a try,
The only thing I would be concerned with is the emulsion's adhesion to the
copper. Silk screens are made from very fine polyester fibers that have a
lot of surface area to "grab" onto and it is formulated for this.

Copper is a horse of another coleor.

Myc


On Mon, Jun 22, 2009 at 11:11 AM, Simao Cardoso <simaocardoso@...>wrote:

>
>
> On Mon, 2009-06-22 at 10:34 +0000, aurangzebhaque wrote:
> > I wonder if it is possible to use the photo sensitive Emulsion used in
> > the silk screen making process directly on the blank PCB copper
> > surface. I realize that in the silk screen process there is the silk
> > mesh in which the emulsion gets trapped and then hardens to form the
> > "screen". The idea that I would like to test is whether:
> >
>
> I also think about it, not to use the 'emulsion' but to buy the
> 'sensiblizer' which is said to be benzenophenone, the same thing used in
> dry films and i think also in LPI and dry film soldermask.
> I know an 'how to' full of pictures with the process. But is Brazilian.
> All Portuguese/Spanish speakers will be fine others...
>
>
> http://br.geocities.com/jaosan13/DicasCustomizacao/PhotoetchEmulsaoFotosensivel.html
>
> Some curious things there is that i talks about the emulsion (without
> sensiblizer) that can be replaced with white hood glue (PVA - water
> soluble also), and the not exposed emulsion he uses is washed with
> simple water.
>
> If you are willing to try, get the benzenophenone, and emulsion, or
> acrylic resin (widely avaiable) or even de PVA glue. The acrylic resin
> should behave like the dry film, develop with Na2CO3 and strip with
> NaOH. But is my guess.
>
> The silkscreen method use this emulsion to make the silkscreen, and
> apply almost anything on the board with it. Acrylic based, epoxy based
> (soldermask), oil based, even asphalt! But yes you can use it directly.
> if you can do an uniform thick layer.
>
> > 1. Will the emulsion initially stick to the copper surface?
> > 2. Will a screen be formed on the copper surface as it does in the
> > case of the silk screening process?
> >
> > Any comments most appreciated.
> >
> > Thanks and regards
> >
> > Aurangzeb
>
> >
>
>  
>


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