I do not suggest a high temperature baking, but I've heard of some people baking to Tg temperature or higher. It is bad for the board, I just wanted to point it out. Alain Savard, B.Sc. Chemical Process Analyst CAE Electronics Ltd. e-mail: [log in to unmask] -----Original Message----- From: Howieson, Rick [mailto:[log in to unmask]] The purpose of baking is to remove moisture. I don't think you need to bake at the glass transition of the laminate. I have mentioned common sense in the TrainerNET forum and it certainly can be applied in this forum. Bueno, Bye Rick Howieson >-----Original Message----- >From: Alain Savard [SMTP:[log in to unmask]] >It increases cross linking inside the epoxy of the laminate, >making is slightly more brittle and harder every time you >bake it. It alsoi ncreases the speed of tin oxide formation, >in effect it ages the board. > >It has also been suggested that a high temperature bake >(> Tg) may cause warpage in a pressed board. ############################################################## 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 ##############################################################