Richard,
I am following the thread. because I like the creative
approach.Regarding accurate placement: Why don't you just place the
components arbitrarily and after potting and peeling of the tape you
scan the side with the exposed pins. With a piece of software (to be
written) the user then can interactively identify the components on the
image. With this information and the schematic the software has all the
information to do the rest, including printing.
Although I can see a few problems with the general approach I think it's
worth following.
Derk
Richard wrote:
>
> Hi gnuv!
>
> On a blank 8.5"x11"x1/4" Corian@ substrate, print out your component
> layout screen (lets say that's a 2.5"x3.5" finished module size) in
> the center of this substrate.
>
> Apply double sided (releasable) "micro-adhesive" tape/film over your
> printed screen (its "micro thin" and "see through").
>
> Apply SMDs with a vacuum assisted "pick and place" probe.
>
> When finished, stack on top your substrate the 8.5"x11"x1/4" Corian@
> potting mold (with the 2.5"x3.5" square hole in the middle).
>
> Epoxy Pot to top of mold. When cured, release potting mold from
> substrate, potting mold is then flipped over, and run through the
> modified printer for conductive and insulative inkjeting.
>
> --- In Homebrew_PCBs@yahoogroups.com
> <mailto:Homebrew_PCBs%40yahoogroups.com>, "gnuvvekaavaali"
> <gnuvvekaavaali@...> wrote:
> >
> > --- In Homebrew_PCBs@yahoogroups.com
> <mailto:Homebrew_PCBs%40yahoogroups.com>, "Richard"
> <richard.liberatoscioli@> wrote:
> > Something else I realized tonight, since the SMDs are "picked and
> placed" onto the "micro adhesive only"(no soldering) the SMDs can be
> placed "end to end" or "side to side" depending on the design of your
> schematic.
> > > >
> > > > For instance, 3 legs from my 64 pin QFN IC go to 6 capacitors,
> each leg going to two capacitors, then all caps go to vdd-.
> > > >
> > > > This normally would take 16 PCB tracks just to do this. By
> > > joining the SMDs "physically", soldered end to end without
> > > wires, from the top surface, I have now reduced my "printed
> > > wiring" down to just 4 connections. Similar printed wiring
> > > reductions are reflected throughout the entire assembly.
> >
> > Wow - very creative effort, indeed.
> > How do you ensure the accuracy of the SMD placement on the tape?
> >
>
>