Process for producing optical waveguide

摘要

The invention provides a process for producing an optical waveguide, which comprises the steps of: continuously applying a polyimide resin precursor layer on a long-sheet substrate and then curing the layer to form a lower cladding layer; continuously applying a photosensitive polyimide resin precursor layer on the lower cladding layer; continuously exposing the applied photosensitive polyimide resin precursor layer to a light through a photomask having a predetermined pattern; continuously conducting post-exposure heating of the exposed polyimide resin precursor layer; continuously developing the polyimide resin precursor layer after the heating to thereby remove unexposed areas thereof and give a predetermined pattern; curing the developed polyimide resin precursor layer to thereby form a core layer having the predetermined pattern on the lower cladding layer; and continuously applying a polyimide resin precursor layer over the lower cladding layer so as to cover the core layer and then curing the precursor layer to thereby form an upper cladding layer.