You may get some insights from a paper I wrote a few years ago for Rogers Corp. http://www.rogers-corp.com/cmu/techtip3.htm Andy Magee - Flex Guru Senior Consultant, Bourton Group [log in to unmask] (937) 435-3629 ps. As you may notice I'm no longer an independent consultant. The Bourton Group (formerly Ingersoll Engineers) specializes in the design and implementation of strategic manufacturing initiatives. We typically work 'hands on' at all levels from the boardroom to the factory floor and produce 'real world' (not just textbook) solutions. ############################################################## 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 ##############################################################