The one comment I have not seen is how fast are you changing the
temperature? Accelerated testing stresses the board across a temp rage at
some given rate of change... rapid changes in temperature can be far more
destructive... it's called thermal shock.
I would expect there to be a temp vs. TIME profile spelled out in the HALT
requirements...  A slow ramp up and down of the temp can be accomplished
without damage, but too fast a rate of change would accelerate the damage
due to uneven expansion or contraction of the materials.


Bill Brooks - KG6VVP
PCB Design Engineer, C.I.D.+, C.I.I.
Tel: (760)597-1500 Ext 3772 Fax: (760)597-1510
Datron World Communications, Inc.
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San Diego Chapter of the IPC Designers Council
Communications Officer, Web Manager
http://dcchapters.ipc.org/SanDiego/
http://pcbwizards.com

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