Polymeric optical waveguide film
The present invention provides a polymeric optical waveguide film whose core and clad are constituted from polymer materials and which is characterized in that a protective layer of a polymer material having resistance to solvent attack higher than that observed for the clad is arranged on at least one of the surface and back face of the waveguide film. The present invention thus permits the preparation of such a film, the clad of which is hardly damaged, which is excellent in the resistance to solvent attack and which never undergoes cracking even when it is bought into contact with a commonly used solvent such as acetone.
1. A polymeric optical waveguide film whose core and clad are constituted from polymer materials, the film being characterized in that a protective layer of a polymer material having resistance to solvent attack higher than that observed for the clad is arranged on each of (1) a surface and (2) a back face of the waveguide film, and wherein the protective layer on the back face is peelable, by immersing in water, from a silicon substrate provided thereon with a silicon oxide film.
2. The polymeric optical waveguide film of claim 1 , wherein the elastic modulus of the film ranges from 2 to 9 GPa.
3. The polymeric optical waveguide film of claim 1 , wherein the polymer material constituting the core and clad consists of a fluorine atom-containing polyimide type resin and the solvent-resistant polymer material consists of a fluorine atom-free polyimide type resin.
4. The polymeric optical waveguide film of claim 3 , wherein the fluorine atom-containing polyimide type resin is a member selected from the group consisting of fluorine atom-containing polyimide resins, fluorine atom-containing poly(imide-isoindolo-quinazolin-dione-imide) resins, fluorine atom-containing poly(ether-imide) resins, fluorine atom-containing poly(amide-imide) resins and any combinations of at least two of them.
5. The polymeric optical waveguide film of claim 2 , wherein the polymer material constituting the core and clad consists of a fluorine atom-containing polyimide type resin and the solvent-resistant polymer material consists of a fluorine atom-free polyimide type resin.