Curable epoxy resin composition for white reflector and cured product of same, substrate for mounting optical semiconductor element, optical semiconductor device, and manufacturing method

The purpose of the present invention is to provide a curable epoxy resin composition for molding a white reflector, whereby a cured product can be formed which has excellent grinding properties and/or tableting properties, is easily handled and has no tackiness, and has excellent heat resistance as well. The present invention is: a curable epoxy resin composition for a white reflector, including a hot mix including an epoxy compound (A) and at least one species selected from the group consisting of an inorganic filler (B) and a white pigment (C), the shear viscosity thereof at 25°C being 10-1000 Pa•s; a cured product of the same; a substrate for mounting an optical semiconductor element having a white reflector formed from the cured product; an optical semiconductor device having an optical semiconductor element mounted on the substrate; and a method for manufacturing the curable epoxy resin composition for a white reflector, a cured product of the same, or the like.