Abstract: The present invention provides a silicone resin transparent substrate, including one or more than one prepreg containing a silicone resin composition and a fibrous base, wherein the silicone resin transparent substrate has: an attached amount of the silicone resin composition to the fibrous base of 60% by mass or more and 99% by mass or less; a total light transmittance of 80% or more at 450 nm, as measured by a method disclosed in JIS K 7375:2008 in a thickness of 0.1 mm to 0.4 mm; and a water vapor permeability of 65 g/m2·day or less, as measured by Lyssy method in conformity with JIS K 7129:2008 in a thickness of 0.1 mm to 0.4 mm; together with a method for manufacturing the same. The silicone resin transparent substrate has excellent heat resistance and weatherability, together with flexibility, high transparency, and lower moisture permeability.

Abstract: The present invention provides a silicone resin substrate, including quartz cloth and a silicone resin composition, wherein the silicone resin composition contains a silicon atom-bonded aryl group in an amount of 10% by mol or more and 99% by mol or less based on the whole silicon atom-bonded organic groups contained in the silicone resin composition. The present invention also provides a metal layer-formed silicone resin substrate, a cured silicone resin substrate, and a metal layer-formed cured-silicone resin substrate, using the silicone resin substrate. Each substrate excels in heat resistance and weather resistance as well as dielectric properties at high frequency.

Abstract: The present invention provides a printed wiring board comprising: a conductor circuit on an insulating substrate, a white solder resist layer which is composed of a photosensitive resin composition on the insulating substrate having the conductor circuit, and a protective layer which is composed of a silicone resin composition on the white solder resist layer. The inventive printed wiring board shows superior thermo-discoloration resistivity and excellent patterning resolution.