Graeme Smith wrote:
> The primary problem as far as I can tell, with extremes of temperatures
> has to do with the substrate of the chip itself. As it gets colder it
> contracts, and as it gets warmer it expands. However because the materials
> we dope with have a different co-efficient of expansion/contraction the
> chip does not expand and contract evenly across the substrate, causing
> stress in the crystal latice, that acts to build up, and create flaws in
> the crystal surface where there is high stress. Over a period of heating
> and cooling cycles, such as is found in a Canadian Car, the crystal is
> flexed over and over again, widening any flaws, and soon, acting to
> separate actual components, or traces from the rest of the circuilt.
>
> The result, is that over time, the chip becomes progressively more and
> more faulty, and some of its functions fail, with eventual death of the
> circuit, much faster than would be expected even in places with
> consistently hot weather.

This may be one of the reasons that nature selected organic life forms
to populate the planet and not anyother, like crystaloid structures. We
can expand and contract under temperature (or wife's pressure) without
our bones being detached from our body's structure...:)

Are you suggesting that this is the reason for the research about
electronic gates based on polymeres instead silicon? Flexibility in
extreme temperature situations?

How they solved this problem in cryogenic processors? I mean, during
certain time, for maintenance or something, it needs to warm back to
ambient temperature, right? they are too expensive to risk the
electronics with contraction/expansion problems.

The Josephson technology for example, it uses macrochips (not micro)
that its connection leads (pins) just enter in small holes filled with
liquid mercury (metal) at room temperature. Liquid Nitrogen puts it to a
very low temperature and as the liquid mercury is the last to contract
and get solid, it fulfill the cavity doing a very good electric contact
between the macrochip pin and the board. I am not sure about that, I saw
a presentation years ago.  But the question is about how that kind of
electronics can stand so low temperature without cracking and just
separate the internal layers of different crystal structures inside the
chips...
Wagner