Re: Deshall creating an Electron Hurricane in my Processor!!!

Trent Piepho (xyzzy@u.washington.edu)
Mon, 5 May 1997 20:26:11 -0700 (PDT)


On Mon, 5 May 1997, Michael R. McClelland wrote:
> Someone mentioned the idea of wearing out a processor and I remembered
> reading about an odd sounding phenomenon in Scientific American(one of my
> favorite sources for odd sounding phenomena),so I dug it up and sure enough
> it states that current flow can erode wires. Go figure. Not so funny now,
> huh?

Yeah, it's called metal migration. What happens is that the amount of current
per square cm that aluminum can carry is only so much. When the chip is made
the traces on it aren't perfectly square, the edges are all jagged. Sometimes
they the wires get narrower than it's supposed to be and it starts to approach
the limit of the wire. When this happens the aluminum atoms start to migrate
away from the write, through a process not completely understood. The wires
gets narrower and thus more overloaded, so the atoms migrate faster, and
because of the resulting positive feedback loop the write eventually breaks.
This can takes years in some cases.

|Gazing up to the breeze of the heavens \ on a quest, meaning, reason |
|came to be, how it begun \ all alone in the family of the sun |
|curiosity teasing everyone \ on our home, third stone from the sun. |
|Trent Piepho (xyzzy@u.washington.edu) -- Metallica |