Hey, I was just surfing, and ended up at a site for a 3D prototype company.
<
http://www.zcorp.com> (interesting in it's own right)
They use an inkjet printer to print a liquid that binds plaster dust
together to
make their models. Sounds almost like regular inkjet except they add
another
set of nozzles that prints clear, and always output the same amount of
liquid.
They print with a full color inkjet head and give full color 3d parts.
But I digress.
Direct printing of a pcb, version 0.01
Make the inkjet head transform in the Y, as well as X axis.
Put a piece of fiber-glass on a flat bed.
Spread powdered solder on the board to an even level.
Print on it, wetting the powder where you want a trace.
Dump off the dry powder.
Put it in a toaster and reflow the stuff the ink kept in place.
If you have surface mount components, put them in place prior to the
reflow.
I think the resolution would be controlled by the fineness of the grind
on the solder
more than the resolution of the printer.
I suspect there are issues with:
grinding the solder fine enough
(not an issue - it's manufactured to the tiny as s--t level)
wetting the powder enough with a regular inkjet
(how thick does powder layer need to be?)
keeping the wet powder right where you want it
(need something that wets the board as well as the solder)
getting the reflowed solder to stay where you want it
(would some kind of flux work as a wetting agent and keep the
reflowed solder from running or balling? means printing flux)
The Dow Corning PI-1000 copper based conductive ink is made with copper
powder and solder powder. The curing process has two purposes:
1) it actually cures the binder
2) it melts the solder powder so that it produces the copper to copper
connection
Using copper keeps the resistance down, and is exactly what we would want.
Using the solder binds everything, just like we would want. I don't
think the fiber
glass would take the temperatures required to 'reflow' the copper powder
by itself,
(not to mention my toaster won't, either) so the solder powder is required.
A quick look showed a number of copper powder manufacturers, and a solder
paste manufacturing uses solder powders. I'll try and get more
information on the
materials next week. it's tough to do on the weekends.
Richard