> -----Original Message-----
> From: owner-filmscanners@halftone.co.uk
> [mailto:owner-filmscanners@halftone.co.uk]On Behalf Of Austin Franklin
> Sent: Wednesday, January 31, 2001 1:37 PM
> To: filmscanners@halftone.co.uk
> Subject: RE: Future of Photography (was filmscanners: real value?)
>
>
They make them smaller for cost reasons, you can put more dies
> (chips) on a
> single wafer, which makes them cheaper. That's not quite the same as
> yield...
>
> > VERY LARGE ICs have been made in the past, but they are very
> > expensive to
> > make because the yields are so poor.
>
> Well, not necessarily true. If you mean large, as in a lot of
> transistors,
> that is true. If you mean physically large, simply because of
> process, that
> is not true.
There is a certain probability that any spot on a wafer will be bad.
Therefore, the larger the chip (physically) the greater the probability that
it will be bad. One caveat is that wafer quality is getting better all the
time and is far superior than what it used to be.
Frank Paris
marshalt@spiritone.com
>
