Photosensitive epoxy resin composition for optical waveguide, curable film for forming optical waveguide, optical waveguide using the same, mixed flexible printed wiring board for optical / electrical transmission, and method for producing the optical waveguide

摘要

The present invention provides a photosensitive epoxy resin composition for an optical waveguide. The photosensitive epoxy resin composition contains: (A) a cresol novolak polyfunctional epoxy resin, the cresol novolak polyfunctional epoxy resin not being fluorene skeleton-containing epoxy resins (C) and (D); (B) a solid bisphenol-A epoxy resin; (C) a solid fluorene skeleton-containing epoxy resin; (D) a liquid fluorene skeleton-containing epoxy resin; and (E) a cationic curing initiator, wherein the components (A) to (E) are each present in a proportion falling within a predetermined range based on the amount of the overall epoxy resin component. Therefore, the photosensitive epoxy resin composition is excellent in coatability, patterning resolution, roll-to-roll process adaptability and the like, and has higher transparency and heat resistance.