BASE WEBS FOR PRINTED CIRCUIT BOARD PRODUCTION USING THE FOAM PROCESS AND ARAMID FIBERS

摘要

A printed circuit board is made from at least one non-woven sheet or web layer comprising at least 10 % weight aramid fibers, with any balance substantially electrically non-conductive fibers, filler, and binder. The sheet or web is preferably made by the foam process, and at least about 10 % (e.g. at least about 60 %) of the aramid fibers utilized are aramid pulp fibers which have a number of advantages compared to the conventional straight aramid fibers. The web or sheet is preferably compressed so that it has a density of about 0.1-0.2 grams per cubic. centimeter; and the web or sheet has a basis weight of between about 20-120 grams per square meter. The web may also have a substantially electrically non-conductive binder such as PVA or an epoxy resin. A printed circuit board made using the aramid layers of non-woven webs or sheets is otherwise conventional, including a pre-preg material, electrically conductive circuit elements, and electronics.