Bill, If you have not already, look at the cooling rate on your reflow oven. I solved a similar similar warpage problem by reducing the solder cooling rate to 1 deg C/second. I had to modify the blowers in the cool down section to achieve that rate. I found my oven was designed to blast the top of the BGA with cold air while the solder was still liquidus. It provided for high speed production, but was warping some of the BGA's. Jim Kittel -----Original Message----- From: Bill Raymond [mailto:[log in to unmask]] Sent: Thursday, September 06, 2001 6:16 AM To: [log in to unmask] Subject: Re: [TN] BGA Warp Werner, thanks for your comments. We are stuck with a single source for this BGA... no one else makes it. Looks like my best bet is to try to talk to the "right" person at the BGA manufacturer. Bill... At 03:56 AM 09/06/2001 -0400, you wrote: >Hi Bill, >BGA warpage is the consequence of an asymmetric [=bad] design. My >recommendation, get somebody else's BGA. >Werner Engelmaier ---------------------------------------------------------------------------- ----- Technet 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 Technet To temporarily halt delivery of Technet send the following message: SET Technet 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 ---------------------------------------------------------------------------- ----- --------------------------------------------------------------------------------- Technet 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 Technet To temporarily halt delivery of Technet send the following message: SET Technet 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 ---------------------------------------------------------------------------------