Hi Frank. I actually wrote one based on the design spec references to I/L clearances and our own manufacturing requirements. The 2221 design spec states that a recc. min trace to edge clearance of .0157 inches be maintained on I/L with additional spacing on outerlayers based on fab and assembly considerations. (Our considerations) (W/ IPC-A-600 allowance of .098 inches of edge nicks or haloing as a guide) We adjusted our figures for worst case (scored edge): +/- .002 for A/W registration. +/- .002 for drill registration. If taking score you need up to .0125 inches from center score for blade width and depth of cut and another .003 inches for blade wander. (the score line can easily be up to .025 in. wide. So we set optimum safe distance on outers (from score centerline to nearest feature) of .035 inches. Routing allows you to decrease that by the score adjustments. Customers are notified when the supplied data violates that and they may opt to allow a change or accept as it. We record and file their response for future reference. This doesn't apply to heatsinks, ground shields or edge connectors of course. And better equipment begets tighter allowances so as we change equipment we will adjust our house spec accordingly. Hope this helps. Steve MacDonald ----- Original Message ----- From: "Franklin D Asbell" <[log in to unmask]> To: <[log in to unmask]> Sent: Monday, August 04, 2003 09:42 Subject: [TN] Score to trace criteria > Is anyone aware of written criteria dealing with scored edge to trace edge > criteria??? design criteria??? specification tolerance, etc etc > > --------------------------------------------------- > Technet Mail List provided as a free 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/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 1.8e 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/html/forum.htm for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 -----------------------------------------------------