In the technet, on Mar1/96 by Ralph Hersey from Lawrence Livermore National Laboratory on High Frequency Transmission Lin; it says now industry is using seed which is later than copper then plate copper on top of it. But this is a high freq. performance killer if the magnetic permeability is greater than 1. I do not understand the reason for this. Could anyone explain this to me? my e-mail : [log in to unmask] Thanks a lot in advance!!!!!! Francis ################################################################ TechNet E-Mail Forum 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's web site (http://www.ipc.org) "On-Line Services" section for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################