Hi Ingemar, I sure hpe it says 6-10 grms, not grams. If it says grams than the document got over-edited by staff thinking this is a typo. grms stands for 'g', the Earth gravitational acceleration constant and rms stands for root-mean-square, and is standard vibration terminology. This is an effective ESS procedure for finding solder joints with latent defects, and comes from some of the old military vibrational requirements. The full details you would have to get from one of the vibration gurus, I am not one of them. In addition, be careful with superBGAs, they warp at high power dissipation and can cause tension induced SJ failures. Werner Engelmaier ############################################################## TechNet Mail List provided as a free service by IPC using LISTSERV 1.8d ############################################################## 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 ##############################################################