Patent ID: 7200313

Claim:
A method for the preparation of an optical waveguide device comprising: (a) a first step for forming a first resin film on a substrate provided thereon with a lower clad layer; (b) a second step for patterning the first resin film into a shape of an optical waveguide to thus form a core layer; and (c) a third step for forming a second resin film by (c1) coating the surfaces of the lower clad layer and the core layer with a solution containing a material for forming the second resin film according to the spin-coating method in such a manner that the thickness of the resulting film as measured from the upper surface of the lower clad layer and as determined after drying ranges from 3 to 10 times the thickness of the core layer and then (c2) drying the coated layer; (d) wherein in the step (c1) of the third step (c), a means for controlling the evaporation rate of a solvent in the solution containing the material for forming the second resin film is provided.