As I read your message, we are not talking about BGAs that were mounted on boards. These are the packages before they were installed? It this true? Yes, I would be worried. Sound like something was wrong in the solder ball attach process. I am not very familiar with commercial methods. Reballing processes that produce wrinkled balls can be caused by excessive heat and excessive convection. > -----Original Message----- > From: TechNet [mailto:[log in to unmask]]On Behalf Of Jindra, Larry > Sent: Friday, March 29, 2002 12:59 PM > To: [log in to unmask] > Subject: [TN] Solder Ball Wrinkles > > > We have a lot of BGA packages from a custom package house with a > "wrinkled" appearance to the ball surface, most pronounced on top > of the ball, where they will interface with the PCB. These > packages are prone to shorting. > > Does anyone out there have an idea of what might cause that > "wrinkled" appearance, and why it might make the package > succeptible to shorting? > > > Larry Jindra > Mfg Engr Group Lead > TRW Radio Systems > [log in to unmask] > w) 858-592-3424 > f) 858-592-3940 > > ------------------------------------------------------------------ > --------------- > Technet Mail List provided as a free service by IPC using LISTSERV 1.8d > 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 delivery of Technet send e-mail to > [log in to unmask]: SET Technet NOMAIL > To receive ONE mailing per day of all the posts: send e-mail to > [log in to unmask]: SET Technet Digest > Search previous postings at: www.ipc.org > On-Line Resources & > Databases > E-mail Archives > Please visit IPC web site http://www.ipc.org/html/forum.htm for additional > information, or contact Keach Sasamori at [log in to unmask] or > 847-509-9700 ext.5315 > ------------------------------------------------------------------ > --------------- > --------------------------------------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d 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 delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives Please visit IPC web site http://www.ipc.org/html/forum.htm for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------