I took your question to mean "what is the total pad size relative to the weight of a device to retain it during double sided reflow without adhesive?" If that is not what you mean then I think you need to enlarge your question. Regards Mike ps OK now Brian? -----Original Message----- From: Walters, Karen [mailto:[log in to unmask]] Sent: Wednesday, July 30, 2003 4:35 PM To: [log in to unmask] Subject: RE: [TN] Isn't this when you need to apply epoxy to hold down the unit. Is there a possibility that we have too much or to little pad spacing causing the unit to float. Please advise? Thank you so much for your input. -----Original Message----- From: Mike Fenner [mailto:[log in to unmask]] Sent: Wednesday, July 30, 2003 11:33 AM To: [log in to unmask] Subject: Re: [TN] This comes up reasonably often and the answer is in the archive therefore. I don't think there is a spec, two numbers are quoted Zarro: 30 gm/ sq in Willis: 44gm/sq in Interesting that both mix their units:) Regards Mike Fenner Indium Corporation of Europe T: + 44 1908 580 400 M: + 44 7810 526 317 F: + 44 1908 580 411 E: [log in to unmask] W: www.indium.com Pb-free: www.Pb-Free.com -----Original Message----- From: TechNet [mailto:[log in to unmask]]On Behalf Of Charles Caswell Sent: Wednesday, July 30, 2003 3:28 PM To: [log in to unmask] Subject: Re: [TN] Idon't know of a spec. for pad size relative to weight. Pad sizes are generally determined by by component footprint. Maybe somebody with SM-275 or SM-782 can help. -----Original Message----- From: Walters, Karen [mailto:[log in to unmask]] Sent: Wednesday, July 30, 2003 8:17 AM To: [log in to unmask] Subject: [TN] Can anyone reference for me the the IPC SPEC that states what the pad surface area requirement is to the weight of the packaged device. We may be having an issue with a floating component during reflow. Please also provide the ratio if anyone knows it off hand. thanks ::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: This email, its content and any files transmitted with it are intended solely for the addressee(s) and may be legally privileged and/or confidential. If you are not the intended recipient please delete and contact the sender by return and delete the material from any computer. Any review, retransmission, dissemination or other use of, or taking of any action in reliance upon, this information by persons or entities other than the intended recipient is prohibited. Messages sent via this medium may be subject to delays, non-delivery and unauthorized alteration. This email has been prepared using information believed by the author to be reliable and accurate, but Indium Corporation makes no warranty as to accuracy or completeness. In particular, Indium Corporation does not accept responsibility for changes made to this email after it was sent. Any opinions or recommendations expressed herein are solely those of the author. They may be subject to change without notice. ::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: --------------------------------------------------- Technet Mail List provided as a free 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/html/forum.htm for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 -----------------------------------------------------