Phil, Is that with or without Nitrogen? Regards, Mike Yuen > -----Original Message----- > From: Phil Zarrow [SMTP:[log in to unmask]] > Sent: Friday, September 17, 1999 11:07 AM > To: [log in to unmask] > Subject: Re: [TN] Bottom Side reflow. > > In my papers on double sided reflow and Intrusive Soldering, I use the > formula: > > Weight of component in grams > total pad to lead mating surface area (in inches) > > and if the result is < or equal to 30 grams, the component will not fall > off. > > Last week, at the SMTA Int'l conference in San Jose, Bob Willis and I > compared further notes and experience on this. We have both used > components > that exceeded 30 grams/in sq but we are sticking with this number. This > incorporates a lot of components including most fine pitch QFPs, TSOPs, as > well as 68 pin PLCC. Trouble components are larger mass components and > many > ceramics including some large tantalums. So experiment with any component > first. > It also assumes that you have a smooth running reflow oven conveyor - no > "shake and bake". > Regards, > Phil Zarrow > ITM, Inc. > Durham, NH USA > www.ITM-SMT.com > > ############################################################## > TechNet Mail List 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 web site (http://www.ipc.org/html/forum.htm) for > additional > information. > If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or > 847-509-9700 ext.5365 > ############################################################## ############################################################## TechNet Mail List 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 web site (http://www.ipc.org/html/forum.htm) for additional information. If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or 847-509-9700 ext.5365 ##############################################################