OPTICAL WIRING RESIN COMPOSITION AND PHOTO-ELECTRIC COMPOSITE WIRING BOARD

摘要

An optical wiring resin composition slightly different in thermal expansion coefficient from an electric wiring board, close in process temperature to it, small in light propagation loss, and suitable for combination with an electric wiring board; and a photo-electric composite wiring board. The optical wiring resin composition is a resin composition comprising inorganic fillers having an average particle size of 1nm through 100nm and resin, wherein the ratio n<SUB>f</SUB>/n<SUB>r</SUB> between the refractive index n<SUB>f</SUB> of the inorganic filler and the refractive index n<SUB>r</SUB> of the resin satisfies 0.8 through 1.2, the thermal expansion coefficient of the resin component is -1×10<SUP>-5</SUP>/°C through 4×10<SUP>-5</SUP>/°C, the true temperature dependency of its refractive index at -20°C through 90°C is -1×10<SUP>-4</SUP>/°C through 1×10<SUP>-4</SUP>/°C, and the resin layer is substantially free from light absorption at a wavelength of 0.6-0.9µm or at a wavelength of 1.2-1.6µm.