Patent Number: 6,309,990

Title: Glass fiber of low permittivity

Abstract: A low-dielectric-constant glass fiber having a glass composition comprising, by % by weight, 45 to 60% of SiO.sub.2, 8 to 20% of Al.sub.2 O.sub.3, 15 to 30% of B.sub.2 O.sub.3, 0 to 5% of MgO, 5%, exclusive of 5%, to 12% of CaO, 0 to 1.0% of Li.sub.2 O+Na.sub.2 O+K.sub.2 O, 0.5 to 5% of TiO.sub.2 and 0 to 2% of F.sub.2 is suitable for use for reinforcing a high-density printed wiring board required to have a low dielectric tangent and its peripheral members.

Inventors: Tamura; Shinichi (Fukushima, JP), Mori; Masahiro (Fukushima, JP)

Assignee: Nitto Boseki Co., Ltd.

International Classification: C03C 13/00 (20060101); H05K 1/03 (20060101); C03C 003/091 (); C03C 003/093 (); C03C 003/118 (); C03C 013/02 ()

Expiration Date: 10/30/2018