--- In
Homebrew_PCBs@yahoogroups.com, Stefan Trethan
<stefan_trethan@g...> wrote:
> On Wed, 04 Feb 2004 17:06:49 -0000, tboneuk_2000
> <a_reynolds@b...> wrote:
>
> > I have just looked at the film I used and discovered the print
may
> > have been the wrong way around. I presume the ink should have
been
> > next to the board, I had this the other way around so the light
hit
> > the ink printed on the film then had to pass through the
transparent
> > film itself before hitting the board.
> > Am I right in thinking this would effect the exposure
efficientcy or
> > will it not make any difference?
> >
> > Kind regards
> >
> > Tbone
> >
> >
>
> it is better to put the ink to the board because of undercutting
of light,
> however i have made
> a few boards the wrong way around and it always worked...
> it should not affect the result in larger copper areas (e.g. a
pad).
>
> ST
Although it may not make a differance I fliped the film over, so the
ink faced the board.
My original trial board was exposed for 4 to 13 mins at 1 min
intervals, now I tried exposing another board for 12 to 30 mins in 2
min steps.
Still not developing, should I see an image of the transfer (even a
faint image) before developing the board ?
One thing that may be worth mentioning is that for this second trial
I used the same deveoping solution that I used for the first (is it
normal to do this or should I have made anew batch for each
development)..?
The original board had an image for few seconds then seem to
dissapear in the solution, this new board exposed for longer had no
such image. Could it be I need to expose for a much shorter time <4
mins ?
Kind Regards
Tbone