Drilling HTE copper normally creates more nailheading than the lower elongation copper but seems to have no other effect. In the Performance Specification IPC-RB-276 the task group elected to remove nailheading as a defect and, of course, it also is not a defect in IPC-6012. The MIL-P-55110E still limits nailheading to 1.5 and is an ancient carry-over to the days when nailheading was a prime indicator of poor drilling. If the board is acceptable to the requirements of the performance specification (nailheading excluded) why must we limit the type of foil we use because of the phony criteria of 1.5 times the thickness. Phil Hinton Hinton "PWB" Engineering *************************************************************************** * 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] * ***************************************************************************