hello, I have a few questions concerning package leadframe materials of integrated circuit packages. I have subscrided only recently to ChipNet and I will submit the same questions there. However, some of the subscribers on TechNet may have valuable info on the subject. -1- are non-copper materials (e.g.Invar, Kovar or Alloy-42 which are Fe-Ni alloys) still used alot for leadframe design of surface mount devices? What is the percentage of copper leadframes on the market today? -2- is there a finish used for copper leadframes and, if so, what materials are used and what is the covered thickness? -3- who has information on or can list references or literature on the complex permeability of non-copper leadframe materials ( (e.g.Invar, Kovar or Alloy-42) All help, however small is appreciated. regards, Jan Vercammen ################################################################ 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 web site (http://jefry.ipc.org/forum.htm) for additional information. For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311 ################################################################