Patent ID: 8351752

Claim:
A production process for a flexible optical waveguide comprising a lower cladding layer, a core pattern and an upper cladding layer, comprising: a step in which a resin film for forming a cladding layer, prepared on a substrate having a ten point average roughness (Rz) of 0.5 μm or more and 10 μm or less on a surface thereof, is used for the lower cladding layer to prepare an optical waveguide, the resin film having a first surface adjacent the substrate and a second surface opposite to the first surface, a resin composition for forming the resin film being curable by ultraviolet radiation, the resin film being prepared by curing the resin composition using ultraviolet radiation, after preparing the resin film for forming the lower cladding layer, a step in which the above substrate is then removed from the resin film for forming the lower cladding layer, leaving said first surface of the resin film which had been adjacent the substrate and said second surface opposite to the first surface, Rz on said first surface, after removal of the substrate, being 0.5 μm or more and 10 μm or less; and a step in which the core pattern of the flexible optical waveguide is provided adjacent the second surface of the lower cladding layer, the core pattern having an optical path transforming part, and the upper cladding layer is provided adjacent the core pattern, the upper cladding layer having a first surface adjacent the core pattern and a second surface opposite the first surface of the upper cladding layer, the second surface of the upper cladding layer having an Rz less than 0.5 μm, the upper cladding layer being formed from a resin composition that is curable by ultraviolet radiation, and wherein providing the upper cladding layer includes curing the resin composition for forming the upper cladding layer by ultraviolet radiation, and wherein providing the core pattern includes exposing and developing a core layer to form the core pattern, said exposing being an exposure of the core layer to an actinic ray with an irradiation dose of 0.01 to 10 J/cm 2 .