Assuming FR4 and interface characteristic tolerance of +/-.005" should not an issue for most US PCB fabricators. Jeffrey Bush Director, Quality Assurance and Technical Support VERMONT CIRCUITS INCORPORATED 76 Technology Drive - POB 1890 Brattleboro, Vermont 05302 Voice - 802.257.4571 ext 21 Fax - 802.257.0011 <http://www.vtcircuits.com/> -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of James Verrette Sent: Wednesday, August 09, 2006 9:54 AM To: [log in to unmask] Subject: [TN] Routed edge tolerance I am trying to figure out what the minimum clearance would need to be between a PCB and a housing that it fits into. The piece I am not sure on is the tolerance of the routed edge of the PCB. The PCB is about .050 thick and the outline is quite complex with curved edges and cutouts. What is the maximum variation in the routed edge that I can expect from the typical mid-high volume board fabricator? I have been told +/-.005 hole to edge and +/-.005 edge to edge. But what is the yield at this tolerance? It is just for straight line routs? The board is 4 layers and cost sensitive, so we don't want to over specify the edge dimension tolerance and drive up cost or limit ourselves to select few board shops. I have also seen quotes from Asian sources recommend punching instead of routing. Where is a good source of layout design guidelines for this process? Does it yield good results? I have some knowledge of singualtion punching, but not in the board fabrication process. Jim Verrette Electrical Engineer --------------------------------------------------- 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 ----------------------------------------------------- --------------------------------------------------- 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 -----------------------------------------------------