We have found that the temperature of 230 deg C doesnot damage the board, except for slight discoloration. In very few cases we reflow boards(FR 4) with a peak of 250 deg C, no damage to the boards. We have not faced any warpage problem. Two thermal cycles are found ok. Sometimes we have gone for three cycles and no problems. regards Sunil Gupta Tata Telecom Ltd. "Tempea, Ioan" <[log in to unmask]> on 21/05/99 23:28:48 Please respond to "TechNet E-Mail Forum." <[log in to unmask]>; Please respond to "Tempea, Ioan" <[log in to unmask]> To: [log in to unmask] cc: (bcc: Sunil Gupta/TTL) Subject: [TN] PCB specs Hi PCB fabs, this one's for you. I'm caught into a lot of fussing about whether my reflowing profiles warp the boards or not. What I'd like to know is if the PCB manufacturers recommend optimal reflow profiles for their boards or, at least, two things: 1. maximum temperatures the boards can withstand without warping or getting damaged in any way 2. maximum number of thermal cycles the board can take, including double reflow, waving and some rework I don't mind if I hear from PCB users either. Have a good week-end after answering, Ioan ################################################################ TechNet E-Mail Forum 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's web site (http://www.ipc.org) "On-Line Services" section for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################ ################################################################ TechNet E-Mail Forum 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's web site (http://www.ipc.org) "On-Line Services" section for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################