Chip operating temperatures

[Robert Harris]

Before being over-concerned about the chip operating temp,
I'd look at the PC board itself.  These boards are nothing but
thin etched metal overlaid on a fiber-glass like material with
a lot of resin.  Every temperature cycle dries out a little more
resin.  They get brittle with age.  They crack with vibration. They
stress with each cycle - the board grows and shrinks at a rate
different than the metal traces.  Think I'm kidding. A desk top
pc generally lasts until the owner can't stand it anymore, while
a laptop is generally a tosser at about 3 to 4 years.  Laptops
get real brittle, with hairline cracks that can't be found or fixed.
Symptoms like random freeze ups etc. = bad board. Why -
vibration - temperature cycles - pressure cycles - that the 
desktop living at human comfort temperatures and no motion
stress does not see.

If it was up to me (and most German, Japanese and American car 
manufactures seem to follow the practice) I'd mount the board 
where there was the least thermal and mechanical stress possible
and minimize the problem.  Just a thought.


-----     Cut here - personal comment follows -----
Q: What's the difference between Jane Fonda and Bill Clinton?
A: She had the balls to go to Viet Nam
  
Robert Harris <bob at bobthecomputerguy.com>