Just fabricated my first PCB today using the photolithography method;
prior PCBs were made using the toner-transfer method. My 10 to 15
mil tracks were faithfully produced. Experimented with 1 and 5 mil
tracks and learned I could do 5 mils but not 1 mils. I believe this
limit is related to the resolution of the artwork I am using. I draw
the track pattern using AutoCAD. It is then printed onto laser-
printer transparency film (CG 3300 by 3M) using my HP LaserJet 2200d
at 1200 dpi and 180 lpi.
When I examine the resulting transparency under a microscope, it
becomes apparent the 1 mil line is poorly rendered. At this time, I
do not know if the limiting factor is the printer or the film.
Does anyone have any ideas/suggestions? One possibility of course is
to have the artwork transparency professionally made.
Lyman
--- In Homebrew_PCBs@yahoogroups.com, Richard <metal@...> wrote:
>
>
> I will second David's comments on the photo process.
>
> I too have been making boards, both 1 and 2 sided, since
> about 1980 using the photo process; and like David, I highly
> recommend it.
>
> You can -easily- achieve 6-8 mil traces/spaces; unlike the
> toner-transfer method where you must use the greatest
> care to achieve a -clean and solid- 10 mils, let alone anything
> finer than that.
>
> In fact, with some careful attention, you can achieve -2 mils-
> with a dryfilm/photo process; which you simply -cannot- do
> with toner transfer, no matter what.