JP2009037005A - Optical waveguide structure and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical waveguide structure and its manufacturing method capable of simply and inexpensively optically coupling an optical waveguide and an optical fiber and having high optical coupling efficiency. <P>SOLUTION: The optical waveguide structure 1 includes: a sheet-like clad part 30 provided on the substrate 10, and formed of a dry film of an optical curing resin or heat curing resin; a core part 40 formed in substantially parallel to the substrate 10 in the clad part 30, and formed of a dry film of the optical curing resin; and an optical fiber 50 in which a part thereof including an end face 51 is buried in substantially parallel to the substrate 10 in the clad part 30, and optically coupling the end face 51 to the end face 42 of the core part 40. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an optical waveguide structure used in, for example, an optical module in the field of optical communication and the like, and a manufacturing method thereof.

  Optical modules, which are electronic components for converting electrical signals and optical signals to each other, are used in various fields such as optical communications.

  This optical module includes an optical transmission module in which an optical fiber for optically transmitting an optical signal from a light emitting element to an outside is optically coupled to a light emitting element such as a surface emitting laser that converts an electrical signal into an optical signal, There is a light receiving module in which a light receiving element such as a photodiode that converts a signal into an electric signal is optically coupled with an optical fiber for transmitting an optical signal from the outside to the light receiving element.

  When assembling these optical modules, an optical element such as a light emitting element or a light receiving element and an optical fiber are appropriately aligned and fixed by means such as active alignment, and both are optically coupled with high efficiency. There is a need. However, when an optical fiber made of quartz is used, it is difficult to align with an optical element, and the manufacturing cost of the optical module increases as the number of optical fiber wires increases.

Therefore, recently, it has been studied to optically couple an optical waveguide using a polymer material to an optical element. For example, Patent Document 1 proposes a technique of forming an optical waveguide using a photosensitive liquid polysilane material and utilizing a photolithography technique.
JP 2005-164762 A

  However, the optical waveguide using such a polymer material has an advantage that a large number of optical waveguides can be formed at one time, but the transmission loss is as large as about 0.1 dB / cm. In order to transmit such a long distance, it is necessary to connect an optical fiber made of quartz to the optical waveguide.

  However, it is difficult to align and fix the optical waveguide using the polymer material and the optical fiber, and the manufacturing cost of the optical module increases. there were. Against this background, there has been a demand for a technique that allows the optical waveguide and the optical fiber to be easily and accurately positioned and fixed at the same time, and that provides high optical coupling efficiency.

  The present invention has been made in view of the circumstances as described above, and can optically couple an optical waveguide and an optical fiber easily and inexpensively and can be physically fixed. Further, high optical coupling efficiency is achieved. It is an object to provide an optical waveguide structure having the same.

  In addition, the present invention provides a method for manufacturing an optical waveguide structure that can optically couple an optical waveguide and an optical fiber with high efficiency in a simple and inexpensive manner and can be physically fixed. It is an issue.

  The present invention is characterized by the following in order to solve the above problems.

  First, an optical waveguide structure of the present invention is provided on a substrate, and is formed of a sheet-like clad portion formed from a dry film of a photocurable resin or a thermosetting resin, and substantially parallel to the substrate in the clad portion. A core part formed from a dry film of a photocurable resin and a part including the end face are embedded in the clad part substantially parallel to the substrate, and the end face is optically coupled to the end face of the core part. And an optical fiber.

  Second, in the first optical waveguide structure, the clad portion includes a lower clad portion formed by laminating and curing a clad dry film made of a photocurable resin or a thermosetting resin on a substrate, and photocuring. A clad dry film made of a mold resin or a thermosetting resin is laminated on a lower clad portion with an optical fiber sandwiched between the core portion and an upper clad portion, and the core portion is made of a photocurable resin. The core dry film is laminated on the lower clad portion, and the core forming portion is cured and formed.

  Third, the optical waveguide structure manufacturing method of the present invention is an optical waveguide structure manufacturing method in which the optical waveguide is optically coupled to an optical fiber, and is made of a photocurable resin or a thermosetting resin. Laminating the clad dry film on the substrate, then curing the clad dry film to form the lower clad part, and fixing the part including the end face of the optical fiber on the lower clad part; , A step of laminating a dry film for core made of a photocurable resin on a lower clad portion to which an optical fiber is fixed, and a core dry through a photomask having an exposure pattern corresponding to the shape of the core forming portion. The film is exposed to light and developed to form a core portion whose end face is optically coupled to the end face of the optical fiber, and the core portion is formed and the optical fiber is fixed. And laminating a dry film for clad made of a photocurable resin or a thermosetting resin on the lower clad part, and then curing the dry film for clad to form an upper clad part. And

  According to the first aspect of the invention, when a dry film of a photocurable resin is used as a core part forming material, and the core dry part is exposed to light by using a photomask to cure the core forming part, the cladding on the substrate is used. Since the substrate and the photomask can be aligned with the optical fiber fixed to the material layer as a reference, the optical waveguide and the optical fiber can be easily optically coupled. Therefore, an inexpensive optical waveguide structure can be provided, and the end face of the core portion is optically coupled with high positional accuracy to the end face of the optical fiber, so that an optical waveguide structure having high optical coupling efficiency is obtained. Provided.

  Furthermore, since a dry film of photo-curing resin or thermosetting resin is used as the material for forming the clad part, the optical fiber and the core part are embedded in the clad part when the dry film exhibits fluidity or plasticity during lamination. Even so, the upper surface of the optical waveguide structure can be made flat. In other words, it was difficult to flatten the upper surface by the conventional spin coating method, but the upper surface can be flattened by using a laminating method, so that an optical waveguide layer or an electric wiring layer can be further formed on the upper surface. It becomes possible.

  Furthermore, since the optical waveguide and the optical fiber can be connected without including an air layer therebetween, reflection loss due to a difference in refractive index with air can be reduced without using an antireflection film.

  According to the second aspect of the invention, the optical fiber is fixed to the flat lower clad portion laminated on the substrate, and when the core portion is formed by exposure, the substrate and the photomask are aligned based on the optical fiber. Thus, the same effect as that of the first aspect of the invention can be obtained, and the end face of the core is optically coupled to the end face of the optical fiber with particularly high positional accuracy, and the optical waveguide structure has particularly high optical coupling efficiency. The body is provided.

  Further, an upper clad portion is formed by laminating and curing a clad dry film made of a photocurable resin or a thermosetting resin on the lower clad portion where the core portion is formed and the optical fiber is fixed. Therefore, when the dry film exhibits fluidity or plasticity at the time of lamination, the upper surface of the optical waveguide structure can be made particularly flat even when the optical fiber and the core are embedded in the cladding.

  According to the third aspect of the invention, the optical fiber is fixed to the flat lower clad portion laminated on the substrate, and when the core portion is formed by exposure, the substrate and the photomask are aligned based on the optical fiber. Thus, the optical waveguide and the optical fiber can be optically coupled easily and inexpensively with high efficiency.

  Further, an upper clad portion is formed by laminating and curing a clad dry film made of a photocurable resin or a thermosetting resin on the lower clad portion where the core portion is formed and the optical fiber is fixed. Therefore, when the dry film exhibits fluidity or plasticity during lamination, the upper surface of the optical waveguide structure can be made flat even when the optical fiber and the core are embedded in the cladding. In other words, it was difficult to flatten the upper surface by the conventional spin coating method, but the upper surface can be flattened by using a laminating method, so that an optical waveguide layer or an electric wiring layer can be further formed on the upper surface. It becomes possible.

  Furthermore, since the optical waveguide and the optical fiber can be connected without including an air layer therebetween, reflection loss due to a difference in refractive index with air can be reduced without using an antireflection film.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1A and 1B are diagrams showing an optical waveguide structure according to a first embodiment of the present invention, in which FIG. 1A is a plan view and FIG. 1B is a longitudinal sectional view. The optical waveguide structure 1 according to this embodiment includes a sheet-like clad portion 30 laminated on a substrate 10, and a plurality of core portions 40 extending substantially parallel to the substrate 10 are provided in the clad portion 30. Is provided. The clad part 30 is formed from a dry film of a photocurable resin or a thermosetting resin, and the core part 40 is formed from a dry film of a photocurable resin.

  Further, a plurality of quartz optical fibers 50 are embedded in the clad portion 30 substantially in parallel with the substrate 10. A part of the optical fiber 50 including the end face 51 is embedded in the clad part 30, and extends from the side end part of the sheet-like clad part 30 to the outside.

  The optical waveguide structure 1 having the above configuration can be suitably used as a component of an optical module, for example. FIG. 2 is a plan view showing an optical waveguide structure according to the second embodiment of the present invention. This embodiment shows an example in which the optical waveguide structure 1 according to the first embodiment is applied to an optical module 2. An optical element 20 is mounted on the substrate 10 of the optical waveguide structure 1, and the optical element 20 is electrically connected to the wiring 11 formed on the substrate 10.

  The optical element 20 includes an optical waveguide configured by the core portion 40 surrounded by the cladding portion 30 and an optical device at the end of the core portion 40 provided in the sheet-like cladding portion 30 on the side opposite to the optical fiber 50. Combined.

  In the thus configured optical module 2 in which the optical fiber 50 is pigtailed, for example, when the optical element 20 is a light emitting element such as a VCSEL (Vertical Cavity Surface Emitting Laser), The optical signal 20 is converted into an optical signal by the optical element 20 and output, and the signal light is transmitted to the outside by propagating through the core portion 40 and then propagating through the optical fiber 50.

  For example, when the optical element 20 is a light receiving element such as a photodiode (PD), signal light transmitted from the outside is propagated from the optical fiber 50 into the core portion 40 and is incident on the optical element 20. As a result, the optical signal is converted into an electrical signal and output through the wiring 11.

  In FIG. 2, the optical module 2 is shown in a simplified manner for the sake of explanation. Specific structures of the optical module 2 include a package form, a multi-chip module, a connector or a socket, etc. Is exemplified. Further, the mounting form of the optical element 20 is exemplified by flip chip mounting by metal bonding or the like, but is not particularly limited as long as the optical element 20 and the wiring 11 are electrically connected. A plurality of optical elements 20 may be mounted on the substrate 10, and examples include a plurality of optical elements 20 arranged in an array. In addition, another electronic component such as a driver IC for the optical element 20 may be mounted on the substrate 10.

  The optical waveguide structure 1 of the present invention can be manufactured by the method described below. Hereinafter, as a third embodiment of the present invention, a method for manufacturing the optical waveguide structure 1 will be described in the order of steps with reference to FIGS.

  First, as shown in FIG. 3, a clad dry film 31 a made of a photocurable resin or a thermosetting resin is laminated on the substrate 10. For laminating, a dry film laminator generally used conventionally, for example, a photosensitive dry film resist used for circuit pattern formation of a printed wiring board and a dry film solder resist used for circuit protection of a printed wiring board are used. A dry film laminator for laminating on a printed wiring board can be used. For example, an apparatus described in JP-A-9-130023 can be used. In order to prevent air entrainment during laminating, an apparatus capable of laminating under reduced pressure may be used.

  When laminating the clad dry film 31a on the substrate 10, as schematically shown in FIG. 3, a three-layer sheet comprising the support film 60, the clad dry film 31a, and the protective film 61 is rolled. The protective film 61 is first peeled off by the peeling roll 70 on the upstream side, and the exposed surface of the clad dry film 31a is opposed to the substrate 10 on the downstream side, and these are attached to the rubber rolls 71 and 72 for pressure bonding. Laminate through.

  As the photocurable resin constituting the clad dry film 31a, the same type of conventionally known photocurable resins can be used. Such a photocurable resin typically contains a monomer, an oligomer, a photopolymerization initiator, and various additives, and is semi-cured in advance to form a dry film. Also good. Similarly, the thermosetting resin contains a monomer, an oligomer, a thermal polymerization initiator, and various additives, and may be semi-cured in advance to form a dry film.

  Specific examples of the photocurable resin include a photocurable epoxy resin, a photocurable acrylic resin, a photocurable halogenated acrylic resin, and a photocurable urethane acrylic resin.

  After laminating the clad dry film 31a on the substrate 10 as shown in FIG. 3, the clad dry film 31a is irradiated with light that promotes a photopolymerization reaction such as ultraviolet light. By curing, or in the case of a thermosetting resin, the clad dry film 31a is cured by heating, as shown in FIG. 4, the substrate 10 on which the sheet-like lower clad portion 31 is laminated is obtained. . Even if the resin is a photo-curing type, it may be heated appropriately for sufficient curing.

  Next, as shown in FIG. 5, the optical fiber 50 is fixed on the lower clad portion 31 laminated on the substrate 10. A part of the optical fiber 50 including the end face 51 is positioned on the lower clad portion 31 and is fixed so that a predetermined number of optical fibers 50 according to the optical signal to be transmitted, the conditions of the optical module 2 and the like are arranged in parallel. .

  As a method for fixing the optical fiber 50 on the lower clad portion 31, an appropriate method such as using an adhesive can be applied as long as the optical fiber 50 can be fixed without being displaced in a subsequent process. The optical fiber 50 may be adhered to the uncured clad dry film 31a laminated on the optical fiber 50, and the optical fiber 50 may be bonded when the clad dry film 31a is photocured.

  After fixing the optical fiber 50 on the lower clad part 31, a core dry film 40a is laminated on the lower clad part 31, as shown in FIG. Lamination can be performed by a method similar to the method of laminating the clad dry film 31 a on the substrate 10.

  As the material for the core dry film 40a, the above-described photo-curable resin can be used, and a material having a higher refractive index than the clad portion 30 after curing is used. In the present invention, either a positive type or a negative type may be used as the photocurable resin, that is, any of those whose solubility in a developing solution is reduced or improved by light irradiation. Good.

Hereinafter, a combination of the clad dry film 31a for the lower clad part 31 (and the clad dry film 32a for the upper clad part 32 described later) and the core dry film 40a, which are preferably used in the present invention, will be exemplified.
Clad dry film 31a (clad dry film 32a): low refractive index material (a) Copolymerization ratio of methyl methacrylate / n-butyl methacrylate / 2-ethylhexyl acrylate / methacrylic acid = 55/8/15/22 (weight basis) (B) Bisphenol FEO-modified diacrylate (“Aronix M-208” manufactured by Toa Gosei Co., Ltd.) 15 parts by weight (c) Epoxy resin (“Epicoat” manufactured by Japan Epoxy Resin Co., Ltd.) 1001 ") 5 parts by weight (d) TPP (triphenyl phosphate) 5 parts by weight (e) tribromophenyl acrylate (" BR-30 "manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 15 parts by weight (f) bis (2, 4,6-Trimethylbenzoyl) phenylphosphine oxide (Ciba Specialty Chemi) "Irgacure 819" manufactured by Ruze Co., Ltd.) 1 part by weight The above components (a) to (f) were mixed to prepare a photocurable resin varnish, and this varnish was placed on a PET film having a thickness of 25 μm as a support film. The film is applied to a desired thickness after drying, and dried at 65 ° C. for 10 minutes to remove the organic solvent and to form a photosensitive dry film in a B stage state. Thereafter, as a protective film, a protect (# 6221F) film (thickness 50 μm) manufactured by Sekisui Chemical Co., Ltd. is laminated to prepare a three-layer structure sheet sandwiching the clad dry film 31a (clad dry film 32a). .
Core dry film 40a: high refractive index material (a) copolymer synthesized at a copolymerization ratio (by weight) of methyl methacrylate / n-butyl methacrylate / 2-ethylhexyl acrylate / methacrylic acid = 55/8/15/22 30 parts by weight (b) Bisphenol FEO-modified diacrylate (“Aronix M-208” manufactured by Toagosei Co., Ltd.) 30 parts by weight (c) Epoxy resin (“Epicoat 1001” manufactured by Japan Epoxy Resin Co., Ltd.) 20 parts by weight ( d) 5 parts by weight of TPP (triphenyl phosphate) (e) 15 parts by weight of tribromophenyl acrylate (“BR-30” manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) (f) Bis (2,4,6-trimethylbenzoyl) Phenylphosphine oxide ("Irgacure 819" manufactured by Ciba Specialty Chemicals Co., Ltd.) 1 part by weight The above components (a) to (f) are mixed to prepare a photocurable resin varnish, and this varnish is dried on a PET film having a thickness of 25 μm as a support film so as to have a desired thickness after drying. By applying and drying at 65 ° C. for 10 minutes, the organic solvent is removed and a photosensitive dry film in a B-stage state is obtained. Thereafter, as a protective film, a protect (# 6221F) film (thickness 50 μm) manufactured by Sekisui Chemical Co., Ltd. is laminated to produce a three-layer structure sheet sandwiching the core dry film 40a.

  As shown in FIG. 6, after laminating the core dry film 40a on the lower clad portion 31, the core dry film 40a is subjected to exposure and development processing for forming a core pattern. As a specific method thereof, a photolithography technique that has been generally used can be applied.

  A specific example thereof will be described with reference to FIG. 7. As shown in FIG. 7A, exposure corresponding to the shape of the core portion 40 to be formed (core forming portion 41 in the plan view of FIG. 7B). A photomask 81 for exposure having a pattern is arranged facing the core dry film 40a on the substrate 10, and further, exposure is performed by irradiating light that promotes a photopolymerization reaction such as ultraviolet light from above, Thereby, the core formation part 41 shown in FIG.7 (b) is selectively photocured. In addition, you may heat after patterning in order to fully harden | cure.

  At this time, for the alignment of the photomask 81 and the substrate 10, a method of aligning the exposure photomask and the circuit forming substrate in the manufacturing process of the multilayer circuit board can be used.

  Specifically, the optical fiber 50 fixed on the lower clad 31 is used as a reference for alignment of the substrate 10, and on the other hand, on the photomask 81, one or a predetermined position with respect to the exposure pattern A plurality of alignment marks are prepared in advance. As the shape and material of the alignment mark, an appropriate one can be selected as long as it can be recognized by the imaging device 80 for imaging and imaging or a stereomicroscope.

  Then, based on the image signal of the imaging device 80 provided on the predetermined table, a relative positional deviation between the reference position of the optical fiber 50 and the alignment mark on the photomask 81 is detected, and the detection result Based on this, a correction value for the relative positional relationship between the optical fiber 50 and the photomask 81 is calculated, and based on this correction value, the substrate 10 and the photomask 81 are moved relative to each other so that they match a predetermined relative position. By doing so, the substrate 10 and the photomask 81 are aligned.

  By applying such an alignment method, and then exposing and curing, the core portion 40 can be formed at a predetermined position with respect to the optical fiber 50 with very high exposure accuracy.

  After selectively curing the core forming portion 41 in FIG. 7B as described above, development is performed using a developer such as a solvent or an alkaline solution, and the core dry film 40a other than the core forming portion 41 is formed. By removing from the lower clad part 31, only the core part 40 remains on the lower clad part 31, and the end face 51 of the optical fiber 50 and the core part 40 are removed as shown in FIGS. The substrate 10 bonded to the end face 42 is obtained.

  Next, as shown in FIGS. 9A and 9B, a clad dry film 32a is further laminated on the lower clad portion 31 on which the core portion 40 is formed and the optical fiber 50 is fixed. Lamination can be performed by a method similar to the method of laminating the clad dry film 31 a for the lower clad portion 31 on the substrate 10. Further, as the material of the clad dry film 32a, the above-mentioned photo-curing resin or thermosetting resin can be used, and usually the same composition as the clad dry film 31a for the lower clad part 31 is used. It is done.

  When the clad dry film 32a is laminated using a dry flumuraminator as shown in FIG. 3, the clad dry film 32a exhibits fluidity or plasticity by heating with the pressure-bonding rubber rolls 71, 72, and the pressure-bonding rubber roll 71 , 72 is applied to the clad dry film 32a and the substrate 10 while pressing the clad dry film 32a, so that the irregularity caused by the optical fiber 50 and the core 40 on the lower clad part 31 can be changed to the above fluidity or plasticity. Thus, the optical fiber 50 and the core portion 40 can be embedded, and the upper surface of the clad dry film 32a can be made flat.

  When a photo-curing resin or thermosetting resin whose fluidity is increased by heating is used as a material for forming the clad dry film 32a, the fluidity can be controlled by the temperature of the pressure-bonding rubber rolls 71 and 72. It is. Further, the clad dry film 32a is preferably in a state of low adhesiveness at room temperature from the viewpoint of handling properties and peelability, and is the most photocurable resin or thermosetting resin used for the clad dry film 32a. As a preferable example, the adhesiveness is low enough to have an appropriate handling property and peelability at room temperature, and fluidity (adhesiveness) to such an extent that the optical fiber 50 and the core part 40 can be embedded by heating at the time of lamination. ) Is given.

  After laminating the clad dry film 32a, the clad dry film 32a is irradiated with light for promoting a photopolymerization reaction such as ultraviolet light to cure the clad dry film 32a, or a thermosetting type. In the case of resin, by curing the clad dry film 32a by heating, as shown in FIG. 1B, the sheet-like upper layer clad portion is sandwiched between the core portion 40 and the optical fiber 50 on the lower clad portion 31. 32 is laminated, and the optical waveguide structure 1 is manufactured as described above.

  Although the present invention has been described above based on the embodiments, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention.

It is the figure which showed the optical waveguide structure in the 1st Embodiment of this invention, (a) is a top view, (b) is a longitudinal cross-sectional view. It is a top view of the optical module provided with the optical waveguide structure in the 2nd Embodiment of this invention. It is a figure explaining the process of laminating | stacking the dry film for cladding on a board | substrate in the manufacturing method of the optical waveguide structure in the 3rd Embodiment of this invention. It is the figure which showed the state which photocured the dry film for clads and formed the lower clad part on the board | substrate, (a) is a top view, (b) is a longitudinal cross-sectional view. It is the figure which showed the state which fixed the optical fiber on the lower clad part, (a) is a top view, (b) is a longitudinal cross-sectional view. It is the figure which showed the state which laminated the dry film for cores on the lower-layer clad part which fixed the optical fiber, (a) is a top view, (b) is a longitudinal cross-sectional view. It is a figure explaining the process of forming a core pattern by exposure, (a) is a figure explaining the operation which aligns and exposes a photomask and a board | substrate, (b) is the plane of the board | substrate which laminated the dry film for cores FIG. It is the figure which showed the state in which the core part was formed on the lower clad part. It is the figure which showed the state which laminated | stacked the dry film for clad on the lower clad part which fixed the optical fiber and formed the core part, (a) is a top view, (b) is a longitudinal cross-sectional view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical waveguide structure 2 Optical module 10 Board | substrate 11 Wiring 20 Optical element 30 Clad part 31 Lower layer clad part 31a Clad dry film 32 Upper layer clad part 32a Clad dry film 40 Core part 40a Core dry film 41 Core formation part 42 End surface 50 Optical Fiber 51 End Face 60 Support Film 61 Protective Film 70 Peeling Roll 71 Pressing Rubber Roll 72 Pressing Rubber Roll 80 Imaging Device 81 Photomask

Claims (3)

  A sheet-like clad portion provided on a substrate and formed from a photocurable resin or thermosetting resin dry film, and provided in the clad portion substantially parallel to the substrate and formed from a photocurable resin dry film. An optical waveguide structure comprising: a core portion; and an optical fiber in which a part including an end surface is embedded in the clad portion substantially in parallel with the substrate, and the end surface is optically coupled to the end surface of the core portion. body.   The clad portion includes a lower clad portion formed by laminating a dry film for clad made of a photocurable resin or a thermosetting resin on a substrate and cured, and a dry film for clad made of a photocurable resin or a thermosetting resin. It consists of an upper clad part formed by laminating and curing a core part and an optical fiber on the lower clad part. The core part is formed by laminating a dry film for core made of a photocurable resin on the lower clad part. The optical waveguide structure according to claim 1, wherein the optical waveguide structure is formed by curing a core forming portion.   A method of manufacturing an optical waveguide structure in which an optical waveguide is optically coupled to an optical fiber, wherein a clad dry film made of a photocurable resin or a thermosetting resin is laminated on a substrate, and then the clad dry A step of curing the film to form a lower clad portion, a step of fixing a part including the end face of the optical fiber on the lower clad portion, and a photocuring on the lower clad portion to which the optical fiber is fixed The core dry film made of a mold resin is laminated, and the core dry film is exposed to light through a photomask having an exposure pattern corresponding to the shape of the core forming portion, and the end face of the optical fiber is developed. A step of forming a core portion optically coupled to the end face; and a photocurable resin or a lower clad portion on which the core portion is formed and the optical fiber is fixed Cladding for dry film comprising a curable resin is laminated, then, the production method of the optical waveguide structure which comprises a step of forming an upper cladding portion by curing the clad dry film.

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