Have you had the opportunity to examine your artwork transparency
(mask) using a microscope? I wonder if it is better than mine. Wish
I had some way to take a photomicrograph so I could post a photo.
I was having some difficulty during the developing process. Some
areas where the resist was supposed to dissolve away were not
becoming completely clean. Assumed it might be due to the dark areas
of my mask not being sufficiently opaque to UV. The dark areas
actually appear grey, not black, when held up to a light. So I
overlaid two masks to increase effective opacity. Placed the toner
side of one mask against the toner side of a mirror image mask. The
down side of this technique is that the toner image is now 4 mils
away from the PCB due to the transparency thickness which, as you
observed, will degrade resolution; but the resulting PCB was
acceptable. In retrospect, I now suspect I did not have to overlay
the masks, but instead only needed to improve the developing process.
So the question I now have is "Does an inkjet printer produce better
masks than does a laserjet printer?".
Lyman
<snip>
> I use genuine epson inkjet transparency and ink in an old stylus
>400 color printer and it gives excellent pinhole-free results and is
>good for tracks and spacing smaller than 8mil.
>