DJ Delorie wrote:
I've found that ink blocks UV better than toner (8 steps vs 3 for
toner). I've heard that "photo" inks have an extra UV inhibitor in
them, but I haven't tried mine to see if they work better than black.
Inkjet is the way to go.
What do you mean by "steps"?
I have a special target footprint I use on my boards - four square
pads with a 1 mil gap between them. Since I use negative prints, this
results in a big sqare hole in the ink with a thin crosshair in it. I
pre-drill registration holes in the pcb, and line up both sides' films
using the targets.
I've pretty much decided on Microtrak after spending most of the evening digging through MSDSes and datasheets. That's a positive-acting resist (i.e. on the transparency, black = copper, clear = blank FR4) which is developed in metasilicate.
I did get a reply from Mega, basically the difference is mainly down to Microtrak being an "inherited" product. Fotoboard is roller-coated, Microtrak is dip-coated. Other than that, the FR4 laminate is basically identical. The shelf life is a guaranteed minimum, not an absolute, so theoretically pre-coated MT should last a while, but will get harder to expose and develop as it ages.
This should be a fun week. :)
--
Phil.
ygroups@...
