John, Yes, you will need to scale 7-8 drill file. My experience is that the registration issues you face with a core that is drilled and plated is going to offer challenges you don't see with respect to typical material movement of the rest of the stack up. 7-8 may not be as predictable, or at least may exhibit wider variation, lot to lot. Nevertheless, it does sound like you can be a lot closer to optimal than your current method of not scaling. Keep in mind there are other issues affecting registration of 7-8 pattern to through pattern, than just scaling the drill file. Once you have the scaling worked out, that may become apparent. Regards, Mark Julstrom Senior Process Engineer Multek Irvine (closed) --------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8e To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/html/forum.htm for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 -----------------------------------------------------