Homebrew PCBs

"Dave Sage" <davesage12@...> writes:
> Making four layer boards sounds interesting but what do you do bout
> the plated through holes. I find even soldering double sided boards
> with no plated holes a bit of a pain.

It's a pain, but this is what I do...

Your stackup is: 32 mil DS clad for power/ground plane "core".  8 mil
SS clad for the two outer signal layers.

Inner layers are for power and ground ONLY.  Wherever you have a
through-via, no problem, solder as usual.  For power/gnd vias, you do
one of two things:

* To connect to the OTHER side's plane, just drill out the whole pad
  on the far side (you aren't using it anyway), exposing the inner
  plane, solder as usual.

* To connect to the SAME side plane, you do NOT drill (or even etch a
  hole) on the plane, just leave it solid.  Put an oversized pad on
  the outer layer and drill it big enough to get a fine-point
  soldering iron in there, and solder a wire from the outer layer to
  the plane.

* When both outer sides connect, you do the oversized copper and hole
  on the plane's side, then re-drill a smaller hole through the board
  (off-center helps).  When you solder the wire through, you should be
  able to get the tip inside the hole to get the inner layer.

Yes, this means you drill a bunch of holes in the outer clad before
adhering the layers together.  I put the sticky tape on the outer
layers before drilling them, so that I drill through the tape also,
then peel the second layer off and stick it to the core.

Obviously, I avoid four-layer boards when I can :-)