Hi George,
Get yourself a copy of IPC-D-279, Design Guidelines for Reliable Surface
Mount Technology Printed Board Assemblies. Appendix a willgive you the
answers you need.

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

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