PRINTED CIRCUIT BOARD MATERIAL

摘要

A resin-impregnated substrate for printed circuits is disclosed, which substrate comprises a fabric woven from warp and fill yarns of glass filaments. The yarns have substantial the same number of filaments therein and are substantially elliptical in cross section when woven. The transverse axis (26) of the warp yarn (24) cross sections has a length that is at least 75 percent of the length of the transverse axis (27) of the fill yarn (25) cross sections. This ensures a thorough impregnation of the fabric by a resin so that voids (16) are avoided which, when filled with materials other than resin, such as plating solution, ultimately produce circuit failures.