| abstract |
An object of the present invention is to provide a thermosetting light-reflecting resin composition which is excellent in reflectance from visible light to near-ultraviolet light after curing, is excellent in heat deterioration resistance or sheet formability, and is less likely to cause burrs during transfer molding, and is used. The optical semiconductor element mounting substrate and the optical semiconductor device of the resin composition. The thermosetting light-reflecting resin composition includes an epoxy resin, a hardener used together with an epoxy resin, a white pigment, and a thickener, wherein the thickener contains a nanoparticle filled with a center particle diameter of 1 nm to 1000 nm. material. |