Method for forming mirror-reflecting film in optical wiring board, and optical wiring board
View Patent ↗An aspect of the present invention is directed to a method for forming a mirror-reflecting film on a waveguide in an optical wiring board, characterized in that a multilayer film, in which a base, a metal layer and an adhesive layer are layered in this order, is used, and the metal layer is transferred and bonded to an inclined face for mirror-reflecting film formation provided on the waveguide, with the adhesive layer of the multilayer film intervening. The present invention provides a method which, when forming a mirror-reflecting film on a waveguide in an optical wiring board, enables inexpensive and easy formation of the mirror-reflecting film, using the smallest quantity of metal possible and employing comparatively simple facilities and techniques.
1. A method for forming a mirror-reflecting film on a waveguide in an optical wiring board, the method comprising:
providing a waveguide with an inclined face
providing a multilayer film, the multilayer film comprising a base layer, a metal layer and an adhesive layer that are layered in this order, and
transferring and bonding, after the providing of the waveguide and of the multilayer film, the metal layer to the inclined face for mirror-reflecting film formation provided on the waveguide, with the adhesive layer of the multilayer film intervening between the metal layer and the inclined face,
the base layer having a uniform thickness.
2. The method for forming a mirror-reflecting film according to claim 1 , wherein the transferring and bonding of the metal layer to the inclined face for mirror-reflecting film formation comprises hardening of the adhesive layer.
3. The method for forming a mirror-reflecting film according to claim 1 , wherein a thermosetting adhesive layer is used as the adhesive layer.
4. The method for forming a mirror-reflecting film according to claim 1 , wherein the transferring and bonding of the metal layer to the inclined face comprises pressing the adhesive layer side of the multilayer film against the inclined face for mirror-reflecting film formation, and applying pressure and/or heat from the base layer side of the multilayer film using a head, wherein a tip of the head comprises an elastic member.
5. The method for forming a mirror-reflecting film according to claim 1 , wherein the metal layer comprises at least one of copper, silver, and gold.
6. The method for forming a mirror-reflecting film according to claim 1 , further comprising dividing the metal layer of the multilayer film into a prescribed shape according to a shape of the inclined face for mirror-reflecting film formation.
7. The method for forming a mirror-reflecting film according to claim 1 , wherein a material which transmits light of wavelength 850 nm is used as the adhesive layer.
8. The method for forming a mirror-reflecting film according to claim 1 , wherein a material with substantially the same refractive index as a core layer of the waveguide is used as the adhesive layer.
9. An optical wiring board, comprising the mirror-reflecting film fabricated by the method according to claim 1 .
10. The method for forming a mirror reflecting film on a waveguide according to claim 1 , wherein an entire surface of the metal layer is covered by the adhesive layer.
11. The method for forming a mirror reflecting film on a waveguide according to claim 1 , wherein the metal layer covers an entire surface of the inclined face.
12. The method for forming a mirror reflecting film on a waveguide according to claim 1 , wherein the inclined face is uniformly covered by the metal and adhesive layers.
13. The method for forming a mirror reflecting film on a waveguide according to claim 1 , further comprising peeling the base layer away from the metal layer bonded to the inclined face.
14. The method for forming a mirror-reflecting film on a waveguide according to claim 1 , wherein the provided multilayer film, comprising the base layer, the metal layer and the adhesive layer are positioned on the inclined face.