Hi Rich,
First you should look at the work reported in IPC-TR-484, "Round Robin
Reliability Evaluation of Small Diameter Plated Through Holes in Printed
Wiring Boards," then you should examine Appendix B of IPC-D-279, "Design
Guidelines for Reliable Surface Mount Technology Printed Board Assemblies,"
and the quickest way to get on board of current thinking on this subject
matter you may want to take the workshop "Design, Manufacturing and
Reliability Issues of Small-Diameter/High-Aspect-Ratio Plated-Through-Holes
and Vias" given this coming Sunday at IPCWorks'97.

Werner Engelmaier
Engelmaier Associates, Inc.
Electronic Packaging, Interconnection and Reliability Consulting
23 Gunther Street
Mendham, NJ  07945  USA
Phone & Fax: 973-543-2747
E-mail: [log in to unmask]

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