FLUOROPOLYMER COMPOSITE MATERIAL FILLED WITH CERAMIC HAVING LOW VOLUME RATIO

摘要

An electrical substrate material comprises a ceramic filled fluoropolymer wherein the ceramic is coated with a silane and the ceramic has a volume % fraction of between 26-45. The substrate exhibits excellent chemical resistance, particularly to alkaline environments. Preferably the silane comprises a blend of at least one phenyl silane and at least one fluorosilane. The silane is preferably coated to a level of greater than 2 to 10% of the total weight of ceramic filler. The present invention has particular utility in filling openings, e.g. ground planes and in bonding multilayer printed wiring boards or constructing printed wiring boards by foil lamination. The ceramic filler is preferably fused amorphous silica. The fluoropolymer is preferably a polymer of tetrafluoroethylene, hexafluoropropene or perfluoroalkyl vinyl ether.