Hi Victor, Criteria cannot be set, because "It Depends" (according to Doug Pauls) on too many variables. These variables are in no particular order: barrel Cu thickness, CTE(post-Tg) of laminate and B-stage layers, resin content (B-stage) Tg, T reached above Tg, drilled hole diameter, surface land diameter, surface land Cu thickness, PCB thickness, non-functional lands, dielectric spacing. An actual assessment can only be done with FEA provided REAL properties are being used (I have yet to see this). Werner ************************************** Get a sneak peek of the all-new AOL at http://discover.aol.com/memed/aolcom30tour --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 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/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------