Homebrew PCBs

> > Me wrote:
> > The CNC drill is a MUST. It is the only
> > sensible way to drill holes before etching.
> 

> Derek with the nice photos wrote:
> It's the only sensible way to drill holes IMO.
> But drilling before etching makes no sense to
> me.

Drilling before etching is what you HAVE to do
if you want through plated holes or multi layer.

Drill holes in blank copper
activate the holewall
Plate the holes through
Apply the photoresist
Develop
Etch
strip

> CNC drilling seemed to have been high on 
> wish lists in the group until the resident
> machinist declared that any backlash greater
> than .001" (or some similar nonsense from his 
> textbook) just wasn't going to cut it.
> Surprisingly, he seems to still drill by hand.

I reckon I woudl be happy with one thou
backlash.  And if I was not happy with it I
reckon I would just always approch a hole from
the same direction.

CNC is a must I feel fot PTH.  If you don't
have CNC you have to do and extra photo 
development at the start to act as guide to
drill by.