Homebrew PCBs

when professionals do even single-sided NON-PTH boards, they
> DRILL
> first, and then etch.  The holes serve as "targets" for laying on the 
> film for
> photo-resist exposure.  This is probably the better method, IF you can 
> drill
> accurately.


> Jan Rowland
> Old Troll
>

I would not say the holes serve as target, i would rather say they (and 
you) have
a cnc drill and so they do not need to align this correctly.
they just punch the holes, and align the resist. i guess it is harder to 
put on the
resist and align the cnc drill...

However i still don't see the advantage - with manual drilling it is not
easier to drill first, i would say it is even harder as you have to aim 
with
the same precision and you have no guiding hole.

ok you can enlarge the pads in the right direction afterwards but that 
doesn't really
count as an argument for me...

ST