Dan, Depends on the solder - the window you suggest may be very roughly OK for conventional solder but if you are using lead free, then your reflow temp will certainly need to be much higher (check the specs of the solder). Also, in my experience, a 2 C/sec ramp up is a little conservative - if you have a good "soak" or level period before rising to relfow you can even things out and so ramp up a bit faster (never had troubles with 2.5 C/sec). 2 C/sec ramp down is definitely slow and there are probably advantages in dropping off much faster, particularly from the reflow peak to well under liquidous (maybe as fast as 4 C/sec?). Just some thoughts. Richard van Beveren NEWTRONICS PTY LTD > -----Original Message----- > From: Dan R. Johnson [SMTP:[log in to unmask]] > Sent: Thursday, 21 February 2002 08:15 > To: [log in to unmask] > Subject: [TN] Safe processing window > > A couple of questions for what has become my best engineering resource. > > Management has asked me to provide a re-flow profile for our product, a > surface mount component built on FR-4 with lead free solder. I am > reluctant, I would prefer to generate a "safe processing window" type > document. As manufacturing professionals what do you prefer? > > The window would spec ; max 2 C /sec ramp up, max 60 sec dwell above 180 > C, max 220 C peak, and a 2 C/sec max ramp down. Could you live with this? > > Many thanks for your help, > Dan --------------------------------------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d 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 delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail 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 ---------------------------------------------------------------------------------