I've been reading about PTH reliability, mainly through Paul Reid's articles and old TN posts from Werner.... If you have a PTH with a surface trace attached to the top side pad, would there be more stress (and thus propensity for cracking / separation between the pad and joining trace) at the pad / trace interface area with a smaller or larger pad size? The "pad rotation" pivots about the knee. A larger pad dia puts the pad-to-trace connection further away from the pivot point and thus the interface area would be subjected to greater deflection. Alternately, a smaller pad area (I believe 6012 requires .002" min) would have less connecting surface area ??? Or is the pad to trace interconnection not a primary failure mode when compared to barrel or corner cracks? Thanks! ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________ --------------------------------------------------- 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 -----------------------------------------------------