Jason,

        If the failed mechanism is corrosion of a glass diode, you may
need to precondition your sample before you subject it to HAST
testing. Preconditioning would most likely consist of temperature
cycling or power cycling, though care must be taken not to
overstress the part beyond the stresses expected in its operating
environment. In addition, during HAST avoid extremely high relative
humidities (i.e., 95%), as you will often get moisture condensation,
which may not be an actual condition in the field.

Best Regards
Craig

Dr. Craig Hillman
CALCE Electronic Products and Systems Consortium
University of Maryland
College Park, MD  20742
(301)-405-5316
[log in to unmask]

##############################################################
TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c
##############################################################
To subscribe/unsubscribe, send a message to [log in to unmask] with following text in
the body:
To subscribe:   SUBSCRIBE TECHNET <your full name>
To unsubscribe:   SIGNOFF TECHNET
##############################################################
Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional
information.
If you need assistance - contact Keach Sasamori at [log in to unmask] or
847-509-9700 ext.5315
##############################################################