Hi Ioan, another classic example of the 'throw-it-over-the-wall' attitude of component suppliers. Werner -----Original Message----- From: Ioan Tempea <[log in to unmask]> To: [log in to unmask] Sent: Thu, 16 Apr 2009 11:25 am Subject: Re: [TN] LGAs in a military environment? What am I going to do with this one then? I have to assemble 3 of them on a fairly large 14 layers RoHS board... http://www.linear.com/pc/downloadDocument.do?navId=H0,C1,C1010,C1778,C1764,P60551,D26185 Please also note the "wise" layout suggested on page 19. Does anybody think about us assemblers? Regards, Ioan Tempea, ing. t : 450-967-7100 ext : 244 [log in to unmask] www.digico.cc P N'imprimer que si nécessaire - Print only if you must -----Message d'origine----- De : Stadem, Richard D. [mailto:[log in to unmask]] Envoyé : 16 avril 2009 11:11 À : [log in to unmask] Objet : Re: [TN] LGAs in a military environment? Bev's assessment is right on. The particular component that Graham's designer wishes to use is a real "problem child" from a long term reliability standpoint, not only because of the fact that it is an LGA with very large delta CTE between component and substrate, but also from the standpoint of having a lot of connections underneath, which reduces cleanability even more. And no-clean fluxes typically don't completely activate underneath a package of this type, even if it were able to be used. --------------------------------------------------- Technet Mail List provided as a serv ice by IPC using LISTSERV 15.0 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 15.0 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 -----------------------------------------------------