NONWOVEN FABRIC MADE OF GLASS FIBER AND PRINTED WIRING BOARDS

摘要

A nonwoven fabric constituted of high-flatness glass fibers whose cross sections have aspect ratios of 2.0 to 10 and rates of filling of 85 % or above, preferably 90 % or above. Such glass fibers have nearly rectangular cross sections and therefore can be arranged in an extremely dense state to give a nonwoven fabric which is extremely thin and has a high bulk density. The fabric can give laminates which are enhanced in the glass fiber content and improved in the surface smoothness, thus being suitably usable as the reinforcement for printed wiring boards. The glass fibers can be produced by the use of, e.g., a nozzle equipped with a tip which has a flat orifice and whose major-axis wall is partially cut out on one side.