Hi Genny, Why would you want to use Cu balls--they do not improve reliability, because the ball is too rigid and you wind up with 2 very thin solder joints. Now polymer balls covered in Cu and solder is another matter--they improve reliability. Werner -----Original Message----- From: Genny Gibbard <[log in to unmask]> To: [log in to unmask] Sent: Wed, 17 Sep 2008 7:00 pm Subject: [TN] Copper BGA balls Anyone have experience with components using a tinned copper ball instead of a SAC alloy solder ball? Have you ever X-rayed one? We are seeing voiding that does not meet the IPC-7095B spec for incoming inspection with a transmission x-ray. However, we don't know if this is a concern for this type of ball, or if this spec even applies to this type of ball. I don't think these are meant to collapse and mix with the solder on the board, like a normal solder alloy ball might. Once again, thanks in advance for sharing your knowledge. Genny --------------------------------------------------- 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 -----------------------------------------------------