>>>>> "STL137" == STL137 <[EMAIL PROTECTED]>
>>>>> wrote the following on Fri, 21 Apr 2000 17:40:55 EDT
STL137> All the recent stuff about HDs and what would cause Prime95
STL137> to fail first got me thinking. I know theoretically about
STL137> "electron wind", the phenomenon that pushes around metal and
STL137> other atoms in chips, albeit slowly. Does anyone know of a
STL137> real instance of a CPU failing due to the electron wind? I
STL137> remember reading that it would take 20 or so years to do so.
When I was still a lad in school, I once went to a presentation given
by AMD. I forget the overall topic of the presentation, but I do remember
one bit quite well. A detail of a small section of the chip was put
up; it looked something like this:
XXX XXX XXX XXX
XXX XXX XXX XXX
XXX XXX XXX XXX
XXXX XXX XXX XXX
XXXXX XXX XXX XXX
XXX XXX XXX XXX
XXX XXX XXX XXX
XXX XXX XXX XXX
XXX XXX XXX XXX
This is a four-bit bus, running up and down, where the X's represent the
metal making up the individual wires.
The reason the guys from AMD had this photo was because this chip had
been returned as defective, after already leaving the plant as
functional. They spent a lot of effort examining this escape.
Notice the defect on the leftmost wire in the bus. The explanation
for the failure was this: The chip was made with an (unintentional)
bump on that wire. The bump wasn't big enough to cause any problems
initially. However, the electric field was stronger at the bump,
making the metal atoms drift that much faster. At some point, the
bump shorted the two wires on the bus, and things stopped working.
Mike
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