Hi Leland - you would need to use analytical techniques for micro-elemental analysis such as Scanning Transmission electron microscopy or Atomic Force microscopy and there is no guarantee that the resulting data would provide a source root cause (plus these techniques are big bucks). Some of the other recommendations from the TechNet crew are much more practical. Dave "Leland Woodall" <[log in to unmask]> 10/28/2009 09:05 AM To "TechNet E-Mail Forum" <[log in to unmask]>, <[log in to unmask]> cc Subject RE: [TN] Birth of a Solderball Hi Dave, Just how many thousands of dollars would that cost, and to what kind of testing do you refer? And I really didn't want to perform a cross section as well, so that was good news! Leland -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of David D. Hillman Sent: Wednesday, October 28, 2009 8:50 AM To: [log in to unmask] Subject: Re: [TN] Birth of a Solderball Hi Leland - It may come as a surprise to many engineers but many metal alloys actually have a "DNA" which can be traced back to original processes and/or original sources. Unfortunately, unless you can find an elemental signature difference in the solder alloy you use in your wave solder process versus your reflow process (which you will need something more sophisticated that standard SEM assessment) you will not be able to determine which process may have produced the solder ball. I don't believe that cross-sectional analysis will be beneficial unless you have some baseline for comparison. Dave Hillman Rockwell Collins [log in to unmask] Leland Woodall <[log in to unmask]> Sent by: TechNet <[log in to unmask]> 10/28/2009 06:54 AM Please respond to TechNet E-Mail Forum <[log in to unmask]>; Please respond to Leland Woodall <[log in to unmask]> To [log in to unmask] cc Subject [TN] Birth of a Solderball TechNetters, Is there any possible way to determine the origin of a solder ball? We've had a failure because of one, and we're trying to determine whether it came from our SMT or wave soldering process. We use SAC305 at both, so using the SEM to determine alloy composition is not really helping. The ball itself is spherical with no "tails" and quite shiny in appearance. If we cross section the ball, will we see a difference in grain structure due to the differences in cool down rates? Is there anything else we can use or do? Thanks in advance for your help! Leland --------------------------------------------------- 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 ----------------------------------------------------- --------------------------------------------------- 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 -----------------------------------------------------