Hi Andy, There is a PTH/PTV model that was developed from IPC accelerated round robin data as well as data from Bell Labs and other sources, taht not only takes geometric design factors and material properties into account, but also the non-uniformities that one gets with actual product. This model was originally published in Engelmaier, W., and L. Turbini, "Design for Reliability in Advanced Electronic Packaging," Proc. Surface Mount International Conf., San Jose, CA, August 1995, pp. 844-879, and an updated version is contained in IPC-D-279, 'Design Guidelines for Reliable Surface Mount Technology Printed Board Assemblies'. I would suspect that this model would serve you better. 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] *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To subscribe/unsubscribe send a message <to: [log in to unmask]> * * with <subject: subscribe/unsubscribe> and no text in the body. * *************************************************************************** * If you are having a problem with the IPC TechNet forum please contact * * Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask] * ***************************************************************************