Hi, We have received some handling instructions from our board supplier, it said prebake prior to assembly 4 hours at 130?C, between the first run and the second run the boards should be stored at a temperature of 80?C. Since we store our boards in a oven with a temperature of 30?C this would mean we need three ovens. (1) Is this a normal procedure for everyone (2) or can we store our boards at 30?C between the first and second run. (3) is there a maximum time for the boards out of the oven (first run) until assembly (reflow_ I did find the following table on the net, but this is only for one run. RECOMMENDATIONS FOR PRE BAKING OF PCB's BEFORE SOLDERING Rigid and Rigid/Flex PCB's FR-4 and Polyimide: PCB's up to 1.0 mm thickness: minimum 2 hours at 120? C PCB's up to 1.8 mm thickness: minimum 4 hours at 120? C PCB's up to 4.0 mm thickness: minimum 6 hours at 120? C Rigid and Rigid/Flex PCB's with Polyimide/Thermount(r): All PCB thicknesses: minimum 6 hours at 135? C Dwell time between baking and soldering is depending on the storage conditions. At 50 % relative moisture the recommended time is max. 8 hours. After baking the PCB's can be kept in vacuum or in an oven at 35?C, which will increase the dwell time. Hilbrand Hi Tech Net, In the near future we will start flow production of flex-rigid boards. The boards are going to be double-sided smt so we will have two runs on our production line. We use an oven for storage with a temperature of 30?C. I have read that we should prebake the boards at 130?C four hours before production. Since this is a double-sided board I would like to know if there are there any requirements for storage between the two runs. Can anyone share his or her experience on the subject? Thanks in advance. Hilbrand --------------------------------------------------- Technet Mail List provided as a 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/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a 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/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 -----------------------------------------------------