Abstract: The invention provides a sheet for optical-semiconductor element encapsulation, which has a multilayer structure including at least two resin layers. The at least two resin layers include: (A) an outermost resin layer (layer A) that is to be brought into contact with one or more optical semiconductor elements; and (B) a resin layer (layer B) disposed on the layer A and having a lower refractive index than that of the layer A. Also disclosed is a process for producing an optical semiconductor device using the sheet.

Abstract: The invention provides a process for producing a light-emitting semiconductor device, which comprises: (1) forming a polycarbodiimide-containing layer on a light takeout side of a light-emitting semiconductor element; and (2) forming irregularities on the surface of the polycarbodiimide-containing layer.

Abstract: The invention provides a sheet for optical-semiconductor element encapsulation, which has a multilayer structure comprising at least two resin layers, the resin layers comprising: (A) an outermost resin layer that is to be brought into contact with one or more optical semiconductor elements; and (B) a resin layer disposed on the layer A and having a lower refractive index than that of the layer A. Also disclosed is a process for producing an optical semiconductor device using the sheet.

Abstract: The invention provides a process for producing an optical semiconductor device, which comprises: (1) forming a resin layer on one or more optical semiconductor elements each mounted on a conductor; and (2) press-molding the resin layer formed in step (1), wherein the optical semiconductor elements each have a vertical section which is tapered from its mounting-side face toward its light emission-side face.

Abstract: The invention provides a process for producing a light-emitting semiconductor device, which comprises: (1) forming a polycarbodiimide-containing layer on a light takeout side of a light-emitting semiconductor element; and (2) forming irregularities on the surface of the polycarbodiimide-containing layer.

Abstract: The invention provides a process for producing an optical semiconductor device, which comprises: (1) forming a resin layer on one or more optical semiconductor elements each mounted on a conductor; and (2) press-molding the resin layer formed in step (1).

Abstract: The invention provides an optical semiconductor device which comprises: an optical semiconductor element; a first resin layer encapsulating the optical semiconductor element and comprising a first resin and light-scattering particles; and one or more resin layers sequentially encapsulating the first resin layer and each comprising a resin having a lower refractive index than the first resin. In an embodiment where the optical semiconductor device has a plurality of resin layers over the first resin layer, the plurality of resin layers are disposed such that the refractive indexes of the constituting resins sequentially decrease toward the outermost resin layer.