Hi All, IPC-2221 9.2.2 Annular Ring Requirements states: "The minimum annular ring on EXTERNAL layers is the minimum amount of copper (at the narrowest point) between the edge of the hole and edge of the land AFTER PLATING of the hole" "The minimum annular ring on INTERNAL layers is the minimum amount of copper (at the narrowest point) between the edge of the drilled hole AFTER DRILLING the hole" I am confused as to why there are two definitions. Can anyone help? I have a few Ideas of my own, but would appreciate an explanation. Best Regards, Mark --------------------------------------------------------------------------------- DesignerCouncil 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 DesignerCouncil. To set a vacation stop for delivery of DesignerCouncil send: SET DesignerCouncil NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail 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 ---------------------------------------------------------------------------------