[PLUG-TALK] Pollution and computer corrosion

[Keith Lofstrom]

Interesting talk at the PSU physics seminar on Monday
Nov 21, by Dr. Karumbu Meyyappan, a researcher at Intel.
Lots of nice microphotographs of failed computer sockets
and circuit boards, many of them from the PC he used in
college in heavily polluted Chennai (chemical pollution
index: Portland 25, Chennai 200, Mumbai 240, Beijing 360).

Moisture and pollutants make acids that corrode copper.
The gold plating used on most connectors and circuit
boards is so thin that it is porous, and the acids
eat the copper through the holes.

The metal-to-metal contact of a card or chip seated
in a socket plugs the holes, but moisture can form a 
meniscus ring around the contact point, and form acid. 
The result is an etched donut around the contact point.
If you jiggle the card or reinsert it, the new contact
point can be in the donut ... fail!

Air cooled data centers may be more energy efficient,
but expose the circuit boards inside the computers to
more pollution.  This may not be a huge problem for
Facebook in Prineville, but air cooled Baidu* near
Beijing is literally being eaten by pollution.

Since Baidu's webspiders were responsible for a large
fraction of my server load, I blacklisted them in the
routing tables.  Seems like Beijing automobile traffic
is blacklisting them, too.  :-/

Keith

*Baidu is a Chinese search engine, like Google except
that it sells user data to China's Ministry of State
Security instead of the U.S. National Security Agency.

--
Keith Lofstrom          keithl at keithl.com