[sdiy] Having a hard time finding the chips you want - roll your own!

[Scott Bernardi]

Analog processes like bipolar usually don't have buried layers - you can see
what's going on from the top (it really is a "planar" process). The different
layers of silox refract the light differently, and neatly outline the different
diffused layers in different colors. Quite pretty, actually.  It's the high
density digital processes that have a lot of buried layers.

Rob B wrote:

> aim : cybrgzr0 <--last thing is a number
> ----- Original Message -----
> From: Czech Martin <Martin.Czech at Micronas.com>
> To: 'Theo' <t.hogers at home.nl>
> Cc: Sdiy (E-Mail) <synth-diy at dropmix.xs4all.nl>
> Sent: Wednesday, August 29, 2001 5:03 AM
> Subject: AW: [sdiy] Having a hard time finding the chips you want - roll
> your own!
>
> > Perhaps it would be better to concentrate on originals
> > that where integrated from the beginneng, ie. SSM and
> > CEM designs, but then we have patent issues, as well as
> > reverse engineering effort.
> >
>
> Well, the chip reverse-engineering isn't all that tough actually.. Just need
> access to a diamond cutter that goes through the layers one by one, about a
> few microns at a time, and a microscope.. It *might* even be possible to do
> it with a CNC mill.You can figure out exactly what the content of the chip
> is that way.. It really doesn't take all that long. You take one picture
> after the next then merge them all. Not more difficult than reverse
> engineering a pcb using the same method of shaving off layers.
>
> The guy I work with right now used to do it for a living! What a waste of
> talent though, since right now he is lucky if he is allowed to solder
> together 2 wires.
>
> Rob

--
Scott Bernardi
sbernardi at home.net