Hi Jon, My application is when we encounter an open in a net containing one or more of these entombed solder balls. We usually can isolate a fault down to a single net through our diagnostics. We can electrically test the PCB or BGA once we remove the BGA, but this destroys any evidence of the root cause if the problem was in the solder joint. I am more concerned about cracks and other types of defects in the solder joint. I guess that this could include unsoldered balls (solder paste application defect) and insufficiently melted solder balls (assembly process defect). If the problem is a solder joint defect, our goal is to understand enough of the source of the defect to determine the extent of any latent problems in the field and work to prevent similar problems in the future. Thanks. Andy [log in to unmask] on 05/30/2006 11:29:12 AM Please respond to TechNet E-Mail Forum <[log in to unmask]>; Please respond to [log in to unmask] To: [log in to unmask] cc: (bcc: Andrew Shieh/CSP) Subject: Re: [TN] solder ball analysis When you are looking at the balls on the BGA for this analysis, what features are you looking to find? Crack? Opens? Unsoldered balls? I know that Micro-CT imaging can get down to sub-micron feature sizes in 3-D. Does that get you the detail you need? Jon Moore --------------------------------------------------- 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 -----------------------------------------------------