I never had a problem with cooling rate all the way up to 42mm package. I have experienced warping on a smaller 'glob top' due to the fast heating ramp of vapor phase. I now only use a convection oven with a 1 - 2 C/sec heat ramp. Jim Kittel > -----Original Message----- > From: Craig Hillman [SMTP:[log in to unmask]] > Sent: Thursday, August 05, 1999 4:00 AM > To: [log in to unmask] > Subject: [TN] Large BGA's > > Hello Technetters, > > Standard vapor phase reflow profiles suggest cooling rates of > between 1-4 degrees C/sec. Has anyone found it necessary to > drastically reduce the cooling rate, down to C/minute, for large > BGA's (45mm x 45mm)? > > Thanks in advance, > Craig > > > Dr. Craig Hillman > CALCE Electronic Products and Systems Consortium > University of Maryland > College Park, MD 20742 > (301)-405-5316 > [log in to unmask] > > ############################################################## > TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c > ############################################################## > To subscribe/unsubscribe, send a message to [log in to unmask] with > following text in > the body: > To subscribe: SUBSCRIBE TECHNET <your full name> > To unsubscribe: SIGNOFF TECHNET > ############################################################## > Please visit IPC web site (http://www.ipc.org/html/forum.htm) for > additional > information. > If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or > 847-509-9700 ext.5365 > ############################################################## ############################################################## TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c ############################################################## To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TECHNET <your full name> To unsubscribe: SIGNOFF TECHNET ############################################################## Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information. If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or 847-509-9700 ext.5365 ##############################################################