10an, I love violent methods. Depending on whether you can sacrifice the board or not, also depending on thickness of board, you may do following. Dip board in liquid nitrogen until stopped boiling, then bend board slightly. If there is a tiny 'ping' , the BGA is ready to be lifted off. Otherwise, use a shear tool and a knee pressure equipment to shear it off. You have to control the move, which ought to be just a fraction of a ball diameter. If you don't have control on shear move, you'll smear the solder ruptures and get no useful sample. I'll send to you some pages out of 185 page report I wrote some years ago about superBGA problems. In that short version I send to you, just have a look at the first pages where you can see how the BGA separated from the board, and how the ruptures look like. Hope this will confuse you still, but at a higher level... Ingemar Hernefjord Ericsson Microwave Systems ----- Original Message ----- From: "Tempea, Ioan" <[log in to unmask]> To: <[log in to unmask]> Sent: Friday, June 16, 2006 3:05 PM Subject: [TN] How to know if a BGA is properly soldered? Hi, first it was the cracked capacitor question, thanks to all who answered. Now I have another one on the ethernal dilemma: is the BGA poorly soldered or there is a design issue? The question is: how can I assess whether the BGA that fails test is properly soldered? I do not have a 5DX and whatever I can see with the Ersascope looks OK. Needless to say, I cannot get the location of the failed pin. Will cross sectioning parallel to the surface of the board tell me anything? Can this be done? Any particularities regarding the polishing of the surfaces? What to look for? Thanks, Ioan --------------------------------------------------- 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 -----------------------------------------------------