Breton

- The question when a failure occurs due to creep is not time based but
strain based. Naturally both are coupled with the deformation rate. This is
the basic idea of the Coffin-Manson relationship.

- Wow  wow, this question is really a trap. I wouldn't dare to name such an
assumption. To stick with Coffin- Manson, each %GBS / %DC would in fact ask
for a damage exponent. Now, since DC leads to a faster degradation than GBS
There might be a line after which GBS becomes negligible. However, as you
see from the diagrams I mailed you, it is not easy to activate pure DC.
Thus it is quite a task to work out the damage exponent for pure DC. At my
present status of know how there is no way to define such a border. As a
matter of fact we where working on this item when the "big bang", leadfree
solder, came. Now I am forced to start a project to do the whole job again.

Best regards

Guenter

##############################################################
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
##############################################################