Its should be soldered by reflow oven or reflow of rework station (the same as for BGAs components). The PCB should be designed with special via holes size for heat transfer (the diameter should be controlled for not sucking the melted solder paste). Best Regards Reuven ROKAH e mail: [log in to unmask] Daan Terstegge <[log in to unmask] To: [log in to unmask] SGROUP.COM> cc: Sent by: TechNet Subject: [TN] IC's with solderable area underneath <[log in to unmask]> 28/10/2004 13:52 Please respond to TechNet E-Mail Forum; Please respond to Daan Terstegge Hi Technet, I'm seeing more and more QFP's and other IC's with a solderable area underneath the package body (heatsink function). Strangely enough not much thought is being given to expectations of designers or to the problems that these components may give in assembly. Does anyone know of standard requirements (i.e. IPC) for the soldered area? When a designer doesn't mention it on the assembly drawing, would you assume that is still mandatory to have solder in that area? If so, how can this requirement be met when using a soldering iron (i.e. Metcal's minihoof tip) to install a QFP for rework or repair? Any other comments with regards to such components? Best regards, Daan Terstegge PCB Assembly Department Thales Land & Joint Systems Tel +31(0)35 524 8297 Fax +31(0)35 524 8181 [log in to unmask] Unclassified Email --------------------------------------------------- Technet Mail List provided as a 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/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a 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/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------