Stephen said:
On Sun, 27 Mar 2005 23:55:41 +0100, Ben Pope
<benpope81@_REMOVE_gmail.com> had a flock of green cheek conures
squawk out:
[...]
The voltage potential causes a current to flow. That current flows
through "thin wires". The "thin wires" have a high resistance. That
high resistance causes the "thin wires" to heat. The heat damages the
"thin wires".
So my point was that heat damages CPUs, not voltage. The voltage causes
a current, which causes the heat, but the voltage itself didn't cause
the damage, the heat did. If the source is current limited, you could
apply a high voltage and not damage the chip.
Metal melts do happen, but junction breakdown and oxide failure are possibly
more important with ESD. Might a really high voltage cause migration across
the n and p layers, making the semiconductor diodes non-functional, without
melting?
There may be some difference between the operative mechanism for damage from
the 1000 to 40,000 volts one may produce walking across the carpet
(dissipated in a millisecond), and damage from supplying an extra 0.5 volts
(over months). Long-term damage occurs at well below the melting points of
many of the metals in semiconductors (though perhaps not below the
temperatures for fast mixing of oxide-metal "alloys"). Latent and/or
long-term failures are probably by very different mechanisms than those that
are caused by ESD.
