Robert Some suggestions Compare a Tg of as received laminate with the finished board. Lower Tg of finished board indicates undercure in your press What glass styles are you using in the prepreg. Is there more resin and less glass in the prepreg layers compared to the laminate, facilitating expansion there? Have you checked the stress level on the plated copper? Good Luck Jerry Sallo Sallo Consulting Services ############################################################## 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 Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ##############################################################