This is a subject that has come up before...it has to do with the TI BGA's with the metal heat sink incorporated into the top of the device. I have x-ray but it doesn't have enough power to penetrate the heatsink. We've recently aquired a Ersascope, I've been using that to inspect first article placement to make sure that we're getting it on the pads...it's been fine. But we still have had a problem with bridging. Out of 50 or so boards, there's been maybe 5-6 boards that have bridged. The bridges have all been in the corners. The balls all seem "squished" because of the weight of the heatsink. I've been looking closely at everything, making sure the print is good, placement is accurate, and that my reflow profile is good too, but I still am seeing this bridging problem... The last time I brought this subject up, I did get conflicting perspectives on this problem with the T.I. parts with the heatsinks in them. One experience shared was that they were having problems processing this part without bridging, and another perspective was from someone that said they built many, many boards with this part and didn't have a problem at all... I'm really trying hard to make sure that everything is as it's supposed to be, print definition and registration, placement accuracy, and reflow profile, but I'm still experiencing this bridging problem, 5 or 6 boards out of 50 isn't good at all...now that I have a Ersascope (because I can't x-ray) it's painfully easy to see the bridges...and like I said, they're mostly on the corners.. Any ideas? -Steve Gregory- ############################################################## TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c ############################################################## To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TECHNET <your full name> To unsubscribe: SIGNOFF TECHNET ############################################################## Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information. If you need assistance - contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ##############################################################