We place large components near the edges, since this is closest to our rails for heat dissipation, and also the edges are least deflected during vibration. Jim Marsico EDO Corporation 1250 New Horizons Blvd. North Amityville, NY 11701 631-630-5079 [log in to unmask] -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Hfjord Sent: Monday, April 16, 2007 12:54 PM To: [log in to unmask] Subject: [TN] Placement of large flatpacks and BGAs close to board edge Dear collegues, I have heard of a thumb rule, never place them along and close to the edge. Hence, we place them (when suitable) in the center. I have forgotten why this rule. Was it because of vibration nodes, warpage during soldering, tempcycle issues or what? Is there a IPC standard or other reference? Inge --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 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 15.0 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 -----------------------------------------------------