Bob, I assume that there must have been some sites where the solder on the pad had wet, or at least partially wet, the BGA solder ball otherwise it would have fallen off instead of having to be pulled off. Besides insufficient wetting could there also have been a Head-On-Pillow issue? Regards, George George M. Wenger Senior Principal Reliability / FMA Engineer Andrew Corporation - Wireless Network Solutions 40 Technology Drive, Warren, NJ 07059 (908) 546-4531 Office (732) 309-8964 Mobile E-mail: [log in to unmask] -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Robert Kondner Sent: Thursday, October 04, 2012 7:46 PM To: [log in to unmask] Subject: [TN] The Great Broken Via Mistery Hi, The other week I had posted about broken vias on an expensive PCB with filled vias. Well, let me inform folks about what really happened. 1. There were no bad vias. The profile used was low, only 221C at one measured spot. They used leaded paste and lead free BGAs. 2. After pulling a part they found nice shiny reflowed pads and nice round BGA balls that had never contacted. 3. Today they fluxed and reflowed a dead board and it came back to life. 4. The Altera reflow process guidelines (AN 353) had errors in the reflow tables. The Altera "Engineer" confirmed the data was good. Now I don't know who started this Bad Via story but my guess is a CM how screwed up doing a profile. Better to point fingers towards the board house is my guess Their "Engineer" thought that if parts got to 250C they would stop working. So using leaded paste on lead free parts was a really smart move. This is a classic case of people using data they think is good and forget to think, ask and observe. Such a big world, so many problem to solve and so much hogwash in so many heads. Bob K. ______________________________________________________________________ This email has been scanned by the Symantec Email Security.cloud service. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________ ______________________________________________________________________ This email has been scanned by the Symantec Email Security.cloud service. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________