This size ceramic BGA on FR-4 would only work in very benign environments (little or no DT). Solder columns would certainly be better, but for this size BGA that is no guarantee either. The reliability of your situation needs to be assessed analytically and/or by accelerated reliability testing. I recommend you look into J-STD-013, Implementation of Ball Grid Array and Other High Density Technology, Section 7, Design for Reliability. I give a one-day workshop "Solder Joint Reliability for Advanced Packages: BGAs, CGAs, TSOPs, etc." at conferences and clients as well as directly consult with clients on solder joint reliability. Werner Engelmaier Engelmaier Associates, Inc. Electronic Packaging, Interconnection and Reliability Consulting 23 Gunther Street Mendham, NJ 07945 USA Phone & Fax: 201-543-2747 E-Mail: [log in to unmask] *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To unsubscribe from this list at any time, send a message to: * * [log in to unmask] with <subject: unsubscribe> and no text. * ***************************************************************************