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AssigneeInternational Business Machines Corporation
InventorsAnilkumar C. Bhatt, Michael J. Cibulsky, Donald E. Doran, Lawrence J. Hugaboom, James W. Knight
Estimating the term…
Woven glass cloth and method of its manufacture suitable for use as a resin-impregnated substrate for printed circuits in which the major dimension or transverse axis of the elliptical warp yarns exceeds a predetermined fraction of that dimension of the fill yarns of the woven cloth. Multi-filament warp yarns are typically subjected to tensile stress during weaving and firing such that the yarn compaction prevents the thorough impregnation by a resin. The result is that voids are maintained along the innermost filaments of the yarn. These voids, when filled with materials other than resin, such as plating solution, ultimately produce circuit failures.
A material for printed circuit substrates comprising a fabric woven from warp and fill yarns of glass filaments with said yarns each having substantially the same number of filaments therein and being substantially elliptical in cross section with the transverse axis of the warp yarn cross sections having a length that is at least 75 percent of the length of the transverse axis of the fill yarn cross sections.
A woven fabric comprising warp and fill yarns of substantially equal pluralities of glass filaments with all said yarns having a substantially elliptical cross section and the length of the transverse axis of said warp yarn cross section when woven being at least 75 percent of the length of the transverse axis of said orthogonal fill yarn cross section.
Dependencies are inferred from the claim text.