Photosensitive resin composition for optical waveguide, photocurable film for formation of optical waveguide core layer, optical waveguide produced by using the resin composition or the photocurable film, and hybrid flexible printed wiring board for optical/electrical transmission
The present invention provides an optical waveguide photosensitive resin composition containing a resin component and a photoacid generator, wherein the photoacid generator has a characteristic property (x) such that an absorption limit (O—O transition energy) calculated based on the shape of an ultraviolet spectrum obtained by spectrometrically analyzing a 0.1 wt % propylene carbonate solution of the photoacid generator by means of an ultraviolet/visible spectrophotometer is 3.5 to 4.1 eV. Where an optical waveguide core layer is formed by using the inventive optical waveguide photosensitive resin composition, for example, the optical waveguide core layer has a lower loss, and is excellent in patternability and reflow resistance.
1. A photosensitive resin composition for an optical waveguide, the photosensitive resin composition comprising:
a resin component; and
a photoacid generator;
wherein the photoacid generator has an absorption limit, which is O—O transition energy, calculated based on the shape of an ultraviolet spectrum obtained by spectrometrically analyzing a 0.1 wt % propylene carbonate solution of the photoacid generator with an ultraviolet/visible spectrophotometer being in a range of 3.5 to 4.1 eV.
2. The photosensitive resin composition according to claim 1 , wherein the photoacid generator comprises at least one photoacid generator selected from the group consisting of general formula (1) and general formula (2):
wherein at least two of R 1 to R 3 are aryl groups, and X is an anion comprising antimony, phosphorus or boron;
wherein R 4 and R 5 , which may be the same or different, are each an aryl group, an alkyl group or a cycloalkyl group, and X is an anion comprising antimony, phosphorus or boron.
3. The photosensitive resin composition according to claim 2 , wherein X is an antimony hexafluoride anion which is SbF 6 .
4. The photosensitive resin composition according to claim 1 , wherein the photoacid generator is present in a proportion of 0.1 to 3 parts by weight based on 100 parts by weight of the resin component.
5. The photosensitive resin composition according to claim 1 , wherein the resin composition is configured to be formed into a core layer provided in a predetermined pattern in a cladding layer for transmission of an optical signal.
6. A photocurable film for formation of an optical waveguide core layer, wherein the photocurable film is produced by forming the photosensitive resin composition according to claim 1 into a film shape.
7. An optical waveguide comprising:
a substrate;
a cladding layer provided on the substrate; and
a core layer provided in a predetermined pattern in the cladding layer for transmission of an optical signal;
wherein the core layer is a core layer formed by curing the photosensitive resin composition according to claim 1 .
8. A hybrid flexible printed wiring board for optical/electrical transmission, wherein the hybrid flexible printed wiring board for optical/electrical transmission comprises the optical waveguide according to claim 7 .
9. An optical waveguide comprising:
a substrate;
a cladding layer provided on the substrate; and
a core layer provided in a predetermined pattern in the cladding layer for transmission of an optical signal;
wherein the core layer is a core layer formed by curing the photocurable film according to claim 6 .
10. A hybrid flexible printed wiring board for optical/electrical transmission, wherein the hybrid flexible printed wiring board for optical/electrical transmission comprises the optical waveguide according to claim 9 .