In a message dated 9/15/98 2:49:29 PM Pacific Daylight Time, [log in to unmask] writes: << For BGAs, particularly CBGAs, a reflow profile with a peak temperature of 219C is too low even for eutectic Sn/Pb solder. Even with high-melt solder balls you should get nice fillets because of the eutectic solder paste. The reliability of the solder joints goes up roughly with the square of the stand-off height. >> Really? Hmmmmm...I've always tried to peak out between 210 - 220 degrees...have I been wrong in doing that? What I thought defined a good generic profile was; 1.) Ramp no more than 2-4 degrees per second. 2.) Dwell for around 1-1.5 minutes at roughly 150 degrees C. to activate the flux and allow everything to come up to temperature together and stabilize. 3.) Ramp a second time to reach 20-30 degrees above the liquidous and hold that for at least 30 seconds, but try to limit it to 1-minute, and don't peak over 220-degrees C.. That's REAL general...but that's what I've always understood to be good basic guidelines for a reflow profile. What should I be peaking at? Is what I thought to be good guidelines passe' now? Am I really hosed up? I have read lately, that "stepped" profiles really aren't necessary. I've read, that you'll get better results with just a gradual, linear rise to peak temperature, then cool. 'Course I know everything depends on your paste formula and ingrediants, but speaking in general terms where am I off-base? -Steve Gregory- ################################################################ 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 ################################################################