Richard,
Based on what you've written here, I'd suggest avidly pursuing the
printing of flux. That approach seems the most likely to yield decent
results. Solder dust printed to a board without flux is gonna just
run all over the place, IMO.
Oooorrrr...
What about using a laserjet and having the toner--which we already
know is thermoplastic-- become the binder for the solder/copper
powder??
Seems to me that if we printed trace outlines directly to the BARE
FRP board--or even ironed it on! after printing to paper-- and then
put a layer of solder/copper dust on top... That if that went into
the oven(set for toner melt temp), the toner would bind the
solder/copper to the board.
Since the toner melts at a lower temperature than the solder copper...
The NEXT step is to brush away the solder copper dust-- which is not
sticking anywhere EXCEPT where the toner was-- and then put the board
into a hotter oven for reflow OF the solder/copper!
Just might work.
Ballendo
P.S. I have several samples from the Zcorp RP machine. Got 'em at
last year's Westec show. One is a ball bearing, workable, all printed
at one time. Pretty cool, but not nearly as durable as the other RP
processes. In times of high humidity the parts tend to crumble.
--- In
Homebrew_PCBs@yahoogroups.com, Richard Mustakos
<rmustakos@a...> wrote:
> 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