Date: Tue, 2 Nov 1999 19:17:59 -0500 From: jong s kadesch <[log in to unmask]> Subject: CGA attachment on BGA pattern Dear TechNetters, I have a substrate with BGA pattern where BGA is fanned out for vias. Dimensions are following: Diameter of the ball: 30 mil Pitch: 50 mil via drill size: 6 mil via with annular ring: 10 mil The substrate is solder masked for CGA attachment but exposing all the vias (no solder mask on vias) and of course, BGA pattern. CGA attachment cannot be done because one BGA pad is too close to the via fanned out from another BGA pad (average distance between two is 5 mil) which will cause short in the event of solder bridge between the BGA pad and the via during eutectic solder reflow process. Is there any way that i can fix this problem without sending these substrates back to manufacturer for remasking? Thanks in advance. Jong Kadesch *************************************** Jong, You might try "reballing" the devices using "hi-temp" spheres (Sn90 Pb10) utilizing eutectic solder paste underprinted by 20%. This will minimize the probability of encroaching liquidus material during reflow. If you have interest in persuing this process on a "test" basis, please feel free to contact me directly. Regards, Ed Popielarski QTA Machine 10 McLaren, Ste. D Irvine, Ca. 92618 949-581-6601 Ph 949-581-2448 Fx http://www.qta.net Ask about our BGA Reballing system! ############################################################## 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 Gayatri Sardeshpande at [log in to unmask] or 847-509-9700 ext.5365 ##############################################################