I have had similar experience with my first board which had BGAs on it. For testing, JTAG was invaluable. To check connectivity, I used to rattle each pin hi/low, and measure some place I had access to the signal. I use proprietary tools running on a proprietary platform (i.e. I have control over everything outside the chip packages) so I don't know how viable this would be with other tools. Also, I discovered that the balls come not at all well soldered to the BGA. I had a via in the centre of each pad and sometimes the ball would just detach from the BGA and flow through the board to make a bullbe at the bottom ... My obvious solution was to fry once the BGA belly (balls) up with some flux prior to soldering it to the board - this works perfectly well. Dimiter -------------------------------------------------------------------- Dimiter Popoff Transgalactic Instruments, Gourko Str. 25 b, 1000 Sofia, Bulgaria http://transgalactic.freeyellow.com Email: tgi@xxxxxx Phone: 00359/2/9923340 -----Original Message----- From: Gupta, Deepali [mailto:Deepali.Gupta@xxxxxxxxx] Sent: Wednesday, September 24, 2003 3:44 PM To: si-list@xxxxxxxxxxxxx Subject: [SI-LIST] Voids in Solder Joints Hi, I have been troubleshooting a board related issue. I have a BGA device soldered on the board which is giving me functional failures. After running x-rays on the device I found some voids in the solder jointon most of the solder balls. I am not sure what kind of problems arise due to voids. Voids does not mean that there is an open joint. I have curve traced al the pins and they give me the correct characeristics so I guess it is making contact. But what would a void do when passing a signal is what I am not sure about. If anyone has dealt with similar issue your feedback would be very helpful. Thanks Regards, Deepali ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List archives are viewable at: //www.freelists.org/archives/si-list or at our remote archives: http://groups.yahoo.com/group/si-list/messages Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu