Gaby, I took the images and played with the contrast and gamma a bit. One can not tweak too much because of the small image size to begin with, but this allowed me to see the solder mask, etc. Of particular interest is image "small1". It appears that the anomaly actually extends beyond the body of the solder bump and out into the underfill/potting and re-surfaces as the 'hole' to the right of the defect. My first reaction was that these were inclusions of some type of foreign matter in the solder joint. It did not look like alloy constituents from the photos provided. Steve -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Gabriela Sent: Saturday, July 04, 2009 3:54 AM To: [log in to unmask] Subject: [TN] Weird solder joints Dear all, By cross sectioning BGA solder joints on a failed assembly, I found that the suspected joints are not uniform and that they contain unusual separation areas. I suspect mixed assembly and/or bad reflow profile. Steve was so kind and enabled me to send the links. Please may I have your opinion? http://stevezeva.homestead.com/files/small.jpg <http://stevezeva.homestead.com/files/small1.jpg> http://stevezeva.homestead.com/files/small1.jpg <http://stevezeva.homestead.com/files/small2.jpg> http://stevezeva.homestead.com/files/small2.jpg http://stevezeva.homestead.com/files/small3.jpg <http://stevezeva.homestead.com/files/small4.jpg> http://stevezeva.homestead.com/files/small4.jpg Gaby --------------------------------------------------- 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 ----------------------------------------------------- --------------------------------------------------- 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 -----------------------------------------------------