Are you sure that the PTV walls have not pulled away from the drilled epoxy thru hole walls prior to your cycling as the result of the soldering processes? The cracking of the copper barrel walls point in that direction also. As pointed out by David Arivett, plating thickness is not necessarily equal to copper quality; it can be uniformly thick, but still have low ductility. Also I suspect that the Hysol SR 1000 has a large thermal expansion coefficient, squeezes out of the PTV at 150C and on cooling there not enough Hysol left to fill the hole so it looks like it is shrinking. Werner Engelmaier Engelmaier Associates, Inc. Electronic Packaging, Interconnection and Reliability Consulting 23 Gunther Street Mendham, NJ 07945 USA Phone & Fax: 201-543-2747 E-mail: [log in to unmask] *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To unsubscribe from this list at any time, send a message to: * * [log in to unmask] with <subject: unsubscribe> and no text. * *************************************************************************** * 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] * ***************************************************************************