Hi Frank... Well... if the board had been laid out properly.... you would not see any power or ground where there was a beveled edge... The designer of the board should make a minimum clearance around the entire board outline to allow a gap between the power/gnd planes and the board edge... in the area where there is to be a beveled edge it may need to be a greater gap than the rest of the perimeter... Most of the board houses I have talked with like to see a .050 min. gap between the edge of the board and the internal planes or circuits. Or any circuits for that matter... top or bottom. this allows a good adhesion of the laminate and prevents shorting between the layers, if the board comes into edge contact with any conductive medium. And it's good design practice... too. Of course, there are exceptions... edge contacts need to come to the edge... etc... but in the illustration you sent below, these are internal planes and should not be exposed by the chamfering process. Bill Brooks Senior PCB Designer - [log in to unmask] Zoneworx, Inc. 40925 County Center Drive, STE 200 Temecula, CA 92591 http://www.zoneworx.com Tel: (909) 296-1226 x 1037 Co-Director / Education Officer / Webmaster for the San Diego Chapter of the IPC Designers Council http://www.ipc.org/SanDiego/index.html http://home.fda.net/bbrooks/pca/ -----Original Message----- From: Franklin D Asbell [mailto:[log in to unmask]] Sent: Wednesday, October 05, 1988 9:36 AM To: [log in to unmask] Subject: [TN] Exposed power-ground plane I need some input from all of you... What specification provides criteria for power-ground planes being exposed due the bevel process, or actually exposed planes for any reason? Or does anyone know the specific criteria, dimension, tolerance, etc for this condition. ---------- ------------\- < exposed power layer ------------/- < exposed ground layer ---------- Thanks, Franklin D Asbell ---------------------------------------------------------------------------- ----- TechNet Mail List provided as a free service by IPC using LISTSERV 1.8d To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF TECHNET 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 ---------------------------------------------------------------------------- ----- --------------------------------------------------------------------------------- TechNet Mail List provided as a free service by IPC using LISTSERV 1.8d To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF TECHNET 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 ---------------------------------------------------------------------------------