Prior art! Prior art! ;')
I made some microwave downconverter PCBs this way, back in 1981 and
82. Very simple boards. I had problems with the paint wicking under
the brass, capillary action sucks the paint right in between the
brass sheet and the copper. It worked, but with a lot of clean up
scraping paint. This was with relatively wide traces and large open
areas. With even full size IC pin spacing, I can't imagine being
able to keep any areas completely free of paint.
I also had to arch thin wires and solder to the brass to support
otherwise disconnected areas. A real pain to keep everything flat.
I might not be picturing what you are saying correctly.
Steve
--- High Tech <
hightechsystems@...> wrote:
>
> Hi Everyone,
>
> I have been thinking about this for a while and I haven't seen it
> mentioned
> before.
> There are many ways to get your idea to copper one I have not
> seen is
> TraceTemplate(TT), for those who have a CNC machine such as
> Crankorgan, I am
> still working on my second one.
> Basically milling out the entire traces of the circuit in a TT
> and spraying
> an etch resist on the pcb. The only thing is you will not have
> center hole
> in your pads it will be solid copper unless you get very
> creative. You could
> also make a second or third TraceTemplate for ground planes.
>
> This only requires a few steps;
> 1. Draw the circuit (CAD,Eagle,ETC or by hand)
> 2. Transfer the drawing to G-code
> 3. Mill a TraceTemplate in plastic, PCB or whatever
> 4. Hold TT against the PCB (clamp together)
> 5. Spray with a Etch resist such as laquer,possibly paint
> 6. Etch
> 7. Remove the resist
>
> The beauty of this is once you have done steps 1-3 all you have
> to do for
> mass production is steps 4-7. Multiple boards can be sprayed at
> once.
> 2-layer boards would be easy with reference holes and you could
> spray both
> sides at the same time. This is going to make it easy to make
> large
> quantities of PCBs for very little money and it will come out the
> same every
> time. Can't wait to start making my TraceTemplate.
>
> Derek B.
> High Tech Systems
> Denver, Co.
>
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