Hi Paul,
Tg is not the whole story, you also need to   look at Td [decomposition
temerature] as well as the CTE. I recommend PCB materials with a STII [Soldering
temperature impact index] of at least 215. The STII is defined as

STII= [Tg + Td]/2 - [% thermal expansion from 50 to 260 C]x10

You may be interested in my workshop on PCB reliability at NPL on October 13.

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, Cell: 386-316-5904
E-mail: [log in to unmask], Website: www.engelmaier.com

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