Thomas, At 07:29 PM 8/13/00 +0200, you wrote: > Dear Technetters, we are currently investigating non-woven aramide >reinforced PI (Poly-Imide) materials for multilayer PWB fabrication. Our >requirement is light weight and high temperature (150 deg C = 300 deg F) >environment, further low TCE to reduce thermal expansion mismatch to large >ceramic components. Formerly we have used metal core multilayer boards, >but now we need to save weight. Who can give us advice on material >selection or share experience with manufacturing (selection of core and >prepreg material) and durability at this high use temperature? Any help >will be appreciated Best regards, Thomas Ahrens [log in to unmask] A.E.A. Technology have been working on SiC/Al metal matrix composites for use as cores in PCBs. These have much lower density than other composite core materials such as Cu/Invar/Cu, whilst also having low expansion and high thermal conductivity. David Whalley ############################################################## 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 Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ##############################################################