Re: Home built PCBs
- To: MISC
- Subject: Re: Home built PCBs
- From: John Griessen <john_g@xxxxxxxxxx>
- Date: Fri, 21 Nov 1997 12:48:50 -0600
If you imagine using a macro circuit printing method to
get a flatter system, or to do glue logic, then speed may
not be the main thing. If speed is the main thing in your
design, then small is beautiful, but you have to get up to
visible scale to connect to sensors or motors or displays
eventually, so that is another place to apply homebrew PCBs.
I am going to try out the direct toner method of printing conductive
paths with a okidata LED printer in a while, so I would like to
hear if anyone has suggestions for that.
Is it really feasible to print plastic transistors? Are the ratios
of length and width anything like in silicon? IF so, then the
registration of the paper handling path in the printer might
allow 4X8 mm transistors with good tolerances. What is it
like using semiconducting plastic juice in a ink jet cartridge?
Messy? Short life of cartridge?
Aside from glue logic and connecting chips, I ran across the
ball semiconductor method web page, which many MISC readers
will be interested in.
http://www.ball.co.jp/ballsemi_e.html
They propose a total abandoning of current semiconductor mfrg
methods. Forget flat surfaces of large wafers. Do photo-
lithographic printing on little 1 mm balls of substrate material
designed to hold only one, or maybe just part of one system.
Circuit interconection is a very limiting barrier right now,
and I did not see where they address it, but what if each
little circuit ball had
a network connection circuit on it--a serial lightwave
bus--then all the little circuit nodes could collaborate.
Think of a 1 mm ball as a substrate for its surface area of
about 2 mm. 2 mm square is 2 million microns, so if the
transistor gate size is .5 micron you could get a 2 million
transistor circuit. If you design it like an F21 istead of
a Pentium, a powerful processor
and memory will fit.
The really exciting near term potential for the ball semi
method is that it can allow quick small batches to run
through the same fab as the high volume stuff.
I did not read if they use low cost masks with
their spherical photolithography method, but I imagine there
is something very different there too. Mask registration
may be done more locally than with masks for planar circuits.
We all see how high volume allows low prices, so that is
a huge benefit to creativity and would enable development
of real circuits by small groups or individuals.
At 11:34 PM 11/21/97 +1000, you wrote:
>:Massive instructions deleted ;
>
>Not like me a number of months ago, testing out an old idea
>of where ever photocopier toner was conductive or not so I
>could make Macro Roms. Of course I got infinitive
>resistence on my Multi-metre.
>
>Anybody interested in homebrew, there are a number of these schemes
>using ink jet printer technology and macro-circuits on the peices of
>plastic, using variouse drawings for the components. So maybe we
>could make processor designs with this.
>
>Certainly would be cheaper than fabbing, but who would be interested
>in buy these macro products, wouldn't they be too slow and not as
>effective as surfacemounting a real chip?
>
>Wayne.
>
>
From: jfox@dnai.com (Jeff Fox)
Subject: Re: MISC-d Digest V97 #49
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Dear MISC readers:
I think the discussion of homebuilt hardware design is quite
interesting. I think there are many people in the group who
are interested.