Thank you for your responses . It was very informative Regards Michel Arbour > -----Original Message----- > From: Arbour, Michel [SMTP:[log in to unmask]] > Sent: Tuesday, July 08, 2003 10:48 AM > To: [log in to unmask] > Subject: [TN] Operating temperature of PCB > > Hello techies, > We have a PCB that is subjected to high temperature during normal > operation > of the product (Power converter). > - There is a heat-sink mounted directly on the PCB on the top side. > - The Dimension of the PCB is : 8" X 3". The heat-sink dim. is : 2" X 4" . > - There is mostly copper planes in the heat-sink area of the PCB . > - The temperature is measured at the bottom side of the PCB and the worst > case temperature is 110C (around 245F) . > - It is a 6 layer PCB thickness of 0.062" .We are using a high temp FR4 . > > Are there any chances of degradation of the PCB over time at these > temperature. > Any reliability issues to adress > Is 175C Tg sufficient . > > --------------------------------------------------- > Technet Mail List provided as a free 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/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 1.8e 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/html/forum.htm for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 -----------------------------------------------------