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| Reply To: | TechNet E-Mail Forum. |
| Date: | Wed, 14 Jan 2004 00:40:24 EST |
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Hi Rich,
1) "what criteria do I use to say whether the differential is OK or not OK? "
A: That depends---use environment, size of LCCC, solder joint height, design
life, accaptable failure probability--as a start, look at IPC-D-279 [you may
also want to look at my web site].
2)" I could also do a stress calculation on the solder joints, but I don't
have a value for Young's
Modulus"
A: That would not be very useful, since solder joints [provided they are of
good quality] do not fail because of overstress, but because of creep-fatigue
in a cyclic environment.
Regards,
Werner Engelmaier
Engelmaier Associates, L.C.
Electronic Packaging, Interconnection and Reliability Consulting
7 Jasmine Run
Ormond Beach, FL 32174 USA
Phone: 386-437-8747, Fax: 386-437-8737
E-mail: [log in to unmask], Website: www.engelmaier.com
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