--- In
Homebrew_PCBs@yahoogroups.com, "thespeakerguy"
<thespeakerguy@y...> wrote:
>
> I was wondering if this may ne a reasonable approach:
>
> 1 - Drill the blank copper clad board with slightly oversize holes.
>
> 2 - Squeeege conductive epoxy into the holes. Cure
>
> 3 - re drill the holes to the correct size
>
> 4 - electroplate, photo mask, then etch.
>
> This assumes a CNC based drill with good repeatability. It could
> work with LPKF and other grinders, as well as home brews
I would think the holes would need to be large. If the hole were
thin, it would not stand up to the presures in re-drilling and would
probably rip out of the hole. I think I would put a hole next to a
hole. The first for epoxy to make a bridge, then one for the part.
That way, re-drilling is not critical.
Considder what Stefan said many months ago.
Look at your board. A resistor can be soldered on both sides, thus
connecting traces, thus eleminating a thru hole for that trace.
With a cap and diode and transistor, it is quickly found that the
unconnected traces are so few that the fix of bridging those
remaining are not a problem.
If you look at your epoxy idea, that could be for those hard to
connect traces. My question is the reliability of the epoxy joint
on conductivity.
Dave