Hello Peter, A safe way to make this determination is to define the slowest conveyor speed, the required profile, the largest BGA, and, the acceptable temperature delta across that BGA. Then, drill a hole thru the backside of the board under the center of the BGA. Mount a thermocouple here on the BGA's center most pad, and, mount another thermocouple in a corner BGA pad. Next profile the board/BGA. Compare what you get with what you expect. From there, you can make a determination if a five zone is acceptable, or possibly acceptable. In my experience, 5 reflow zones do give enough profile definition and can be acceptable if the conveyor speeds meet required line speeds. Note: Cooling (the downward side of TAL) warrants as much attention as heating. Hope this helps, Shean Dalton Austin American Technology www.aat-corp.com <http://www.aat-corp.com> -----Original Message----- From: Crain, Peter (GE Energy) Sent: 9/21/2004 11:43 AM To: [log in to unmask] Subject: [TN] New reflow oven needed for BGAs??? Hi all, We are looking at placing BGAs. We currently use a 5 zone reflow oven that does a great job of soldering all other components. In fact, we only have a few profiles which are used on many products. Is there a need for more zones when going to BGA? Does size BGA size matter? Thanks in advance, Peter --------------------------------------------------- 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 847-509-9700 ext.5315 ----------------------------------------------------- --------------------------------------------------- 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 847-509-9700 ext.5315 -----------------------------------------------------