If you allow "tangency" of drilled hole wall to signal pad feature, then the antipad on a plane layer must be "signal pad + 2(.0085") - that means the drilled hole if in spec (no breakout) will always be .0085" min. from the copper plane. If you require 0.001" of annular ring, then you can make the antipad "(signal pad - 0.001" + 2(.0085"). .... NPTHs just need to have .0085" annular ring "copper keep out zone" .. Valerie mattyk <[log in to unmask]> Sent by: TechNet <[log in to unmask]> 02/03/2006 10:54 AM Please respond to TechNet E-Mail Forum <[log in to unmask]>; Please respond to mattyk <[log in to unmask]> To [log in to unmask] cc Subject Re: [TN] In layman's terms, please? That means no copper feature less than 8.5mils from edge of drill hole -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Genny Gibbard Sent: Friday, February 03, 2006 10:52 AM To: [log in to unmask] Subject: [TN] In layman's terms, please? What does "minimum drill to metal spacing less than 8.5mils is not allowed" mean? We must respond to a customer that our design meets this. Thank you once again for sharing your wisdom... --------------------------------------------------- Technet Mail List provided as a 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/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- Genny