Hi Chetan,
Yes, what you are seeing is the result of the T-stress test; this test is
designed to mimic the worst loading during solder processes resulting from
the thermal expansion mismatches of the various materials (actually, manual
soldering can be worse). Thus, passing this test in a way means that your PWB
will survive soldering processes; by implication it also means that it will
be reliable in service. Failing the test, if no severe soldering processes
take place, does however not necessarily mean your PWBs will not be reliable
in service; this will depend on the severity of the service environment.
It is possible, that for your construction and assembly sequence the T-stress
test is not fully appropriate.

Werner Engelmaier
Engelmaier Associates, L.C.
Electronic Packaging, Interconnection and Reliability Consulting
7 Jasmine Run
Ormond Beach, FL  32174  USA
Phone: 904-437-8747, Fax: 904-437-8737
E-mail: [log in to unmask], Website: www.engelmaier.com

##############################################################
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 Gayatri Sardeshpande at [log in to unmask] or
847-509-9700 ext.5365
##############################################################