Homebrew PCBs

Philip Pemberton <ygroups@...> writes:
> As far as OHP transfers go, I've got both a laser (Panasonic
> KX-P7110) and an inkjet (Canon iP4600) printer. Which one is likely
> to produce better results for PCB work?

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.

The tricky part is getting films that will take enough ink.  I ended
up getting some Jetstar and Silkjet films which work pretty well.

> Lastly, I'd like to know if anyone has any hints on aligning the
> transfers for double-sided work.

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.