JP2011221193A - Optical wave guide structure and electronic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical wave guide structure including an optical wave guide which has a high degree of freedom for a design of a pattern shape, allows a core portion (optical path) to be formed with superior dimensional accuracy in a simple method and is superior in heat resistance and durability, and an electronic device.SOLUTION: An optical wave guide structure 1 includes: a substrate 2 having conductor layers 5; an optical wave guide 9 which is configured such that a core layer 93 and cladding layers 91, 92 are laminated; a light-emitting element 3 disposed on one end of the optical wave guide 9; and a light-sensitive element 4 disposed on the other end of the optical wave guide 9. Further, these components constitute an optical wiring 98, and a coating layer 7 is provided so as to coat the optical wiring 98. The coating layer 7 is constituted of fire-retarding material such as polyimide resin and polyamide resin.

Description

  The present invention relates to an optical waveguide structure and an electronic device.

  In recent years, optical branching couplers (optical couplers), optical multiplexers / demultiplexers, and the like have been developed as optical components in the field of optical communications, and optical waveguide devices used for these are promising. As this optical waveguide type element (hereinafter, also simply referred to as “optical waveguide”), there are polymer optical waveguides that are easy to manufacture (patterning) and are versatile, in addition to conventional quartz optical waveguides. Is being actively developed.

  Such an optical waveguide is usually formed in a predetermined arrangement (pattern) on a substrate and handled as an optical waveguide structure. As this optical waveguide structure, a structure in which a predetermined electric wiring circuit and an optical waveguide composed of a core portion and a cladding portion are formed on a substrate, and a light emitting element and a light receiving element are attached to the optical waveguide is disclosed. (For example, refer to Patent Document 1).

  However, the optical waveguide structure described in Patent Document 1 has the following problems.

1. The process of forming the optical waveguide is complicated, and the degree of freedom in designing and selecting the pattern shape of the core part constituting the optical path of the transmitted light is narrow.
2. The core pattern shape accuracy and dimensional accuracy are poor.
3. Optical signal transmission efficiency is low.
4). When combined with an electrical wiring pattern, the degree of freedom in designing the electrical wiring pattern is narrow.

JP 2004-146602 A

  An object of the present invention is to provide a core part (optical path) having a wide degree of freedom in designing a pattern shape and having high dimensional accuracy by a simple method, and an optical waveguide having excellent heat resistance and durability. An object of the present invention is to provide an optical waveguide structure and an electronic device.

Such an object is achieved by the present inventions (1) to (28) below.
(1) An optical waveguide including a core portion and a cladding portion having different refractive indexes, and a coating layer provided to cover the optical waveguide and made of a flame retardant material,
The core part is
(A) a cyclic olefin resin;
(B) The refractive index is different from that of (A), and at least one of a monomer having a cyclic ether group and an oligomer having a cyclic ether group;
(C) a photoacid generator;
An optical waveguide structure characterized by being formed into a desired shape by selectively irradiating active radiation to a core layer composed of a composition comprising:

  (2) The optical waveguide structure according to (1), wherein the cyclic ether group of (B) is an oxetanyl group or an epoxy group.

  (3) The optical waveguide structure according to (1) or (2), wherein the cyclic olefin resin (A) is a norbornene resin.

(4) The refractive index of (B) is lower than that of (A),
(1) The cyclic olefin resin has a leaving group that is desorbed by an acid generated from the photoacid generator of (C) and lowers the refractive index of (A) by desorption. Thru | or the optical waveguide structure in any one of (3).

(5) The cyclic olefin resin of (A) has a leaving group that is eliminated by an acid generated from the photoacid generator of (C) in the side chain,
Said (B) is an optical waveguide structure as described in said (2) containing the 1st monomer as described in following formula (100).

  (6) The optical waveguide structure according to (5), wherein (B) further includes at least one of the epoxy compound and the oxetane compound having two oxetanyl groups as the second monomer.

  (7) The ratio of the second monomer to the first monomer is 0.1 to 1.0 in a weight ratio (weight of the second monomer / weight of the first monomer). The optical waveguide structure described.

  (8) The leaving group may have at least one of an -O- structure, an -Si-aryl structure, and an -O-Si- structure. The optical waveguide structure described.

  (9) The optical waveguide structure according to any one of (5) to (8), wherein the cyclic olefin resin of (A) is a norbornene resin.

  (10) The optical waveguide structure according to (9), wherein the norbornene-based resin is a norbornene addition polymer.

［式中のｎは、０以上９以下の整数である。］ (11) The optical waveguide structure according to (10), wherein the norbornene addition polymer has a repeating unit represented by the following formula (101).

[N in the formula is an integer of 0 or more and 9 or less. ]

(12) The optical waveguide structure according to (10) or (11), wherein the norbornene addition polymer has a repeating unit represented by the following formula (102).

  (13) The content of the first monomer described in the formula (100) is 1 part by weight or more and 50 parts by weight or less with respect to 100 parts by weight of the cyclic olefin resin. An optical waveguide structure according to claim 1.

  (14) The light according to any one of (1) to (13), wherein the concentration of the structure derived from (B) is different between a region irradiated with active radiation of the core layer and a non-irradiated region. Waveguide structure.

  (15) The optical waveguide structure according to any one of (1) to (14), wherein the refractive index difference between the region irradiated with active radiation and the non-irradiated region of the core layer is 0.01 or more.

  (16) The structure according to any one of (1) to (15), wherein the region of the core layer that has been irradiated with active radiation is at least a part of the cladding part, and an unirradiated region is at least a part of the core part. Optical waveguide structure.

  (17) The optical waveguide structure according to any one of (1) to (16), wherein the flame retardant is a resin material containing a polyimide resin or a polyamide resin.

  (18) The optical waveguide structure according to (17), wherein the coating layer is formed by applying the liquid resin material so as to cover the optical waveguide and then curing the resin material.

  (19) The optical waveguide structure according to any one of (1) to (18), wherein the flame retardant material has a flame retardance of HB or more according to a UL-94 test.

  (20) The optical waveguide structure according to any one of (1) to (19), wherein the flame retardant includes a flame retardant filler having flame retardancy.

  (21) The optical waveguide structure according to any one of (1) to (20), wherein an average thickness of the coating layer is 10 to 200 μm.

(22) A first support member that supports one end portion of the optical waveguide, and a light emitting element provided on the first support member, the one end portion of the optical waveguide, and the light emitting portion of the light emitting element, An optical transmitter configured to be optically connected;
A second support member for supporting the other end of the optical waveguide; and a light receiving element provided on the second support member; and the other end of the optical waveguide and the light receiving unit of the light receiving element. An optical receiver configured to be optically connected,
The optical waveguide structure according to any one of (1) to (21), wherein at least one of the light emitting element and the light receiving element is covered with the coating layer.

(23) The optical transmission unit further includes a driving circuit that is provided on the first support member and drives the light emitting element.
The optical receiver is further provided with an amplifying circuit provided on the second support member for amplifying a signal obtained from the light receiving element,
The optical waveguide structure according to (22), wherein at least one of the driving circuit and the amplification circuit is covered with the coating layer.

(24) Furthermore, it has a conductor layer provided on at least one surface side of the optical waveguide, on which electrical wiring is formed,
The optical waveguide structure according to any one of (1) to (23), wherein the conductor layer is covered with the covering layer.

(25) The optical waveguide has an optical path conversion part that bends the optical path of the core part in the middle of the longitudinal direction,
Of the longitudinal direction of the optical waveguide, at least a part of either side sandwiching the optical path conversion unit and not optically connected to the optical path conversion unit is made of the constituent material of the optical waveguide. The optical waveguide structure according to any one of (1) to (24), which is made of a carbonized material.

  (26) The light guide according to (25), wherein the side of the optical waveguide that is not optically connected to the optical path conversion unit is configured only by a material obtained by carbonizing the constituent material of the cladding unit. Waveguide structure.

(27) The conductor layer is provided on one surface side of a flexible substrate having flexibility, and constitutes a wiring substrate together with the flexible substrate,
The optical waveguide structure according to any one of (1) to (26), wherein the wiring board is covered with the covering layer.

  (28) An electronic apparatus comprising the optical waveguide structure according to any one of (1) to (27).

  According to the present invention, the core portion can be patterned by a simple method of light irradiation, and the core portion having a wide degree of freedom in designing the pattern shape of the core portion and high dimensional accuracy can be obtained.

  Moreover, since the coating layer is covered with a coating layer made of a flame retardant material, an optical waveguide structure excellent in heat resistance and durability can be obtained.

  In addition, when the core part is composed of a resin composition mainly composed of norbornene resin (cyclic olefin resin), the effect of being particularly strong against deformation and being difficult to cause defects is high, and the core part and the clad part The difference in refractive index can be further increased, and the optical waveguide is excellent in heat resistance. As a result, an optical waveguide having higher performance and excellent durability can be obtained.

  In addition, both electric circuits and optical circuits can be easily formed, and various shapes can be formed with high dimensional accuracy. In particular, the optical circuit can be formed with any shape and arrangement of the optical path (core part) by selecting the exposure pattern, and it can be sharply formed even with a thin optical path. This contributes to reducing the size of the device.

  Such an optical waveguide structure of the present invention has a wide range of optical circuit (optical waveguide pattern) and electrical circuit design, high yield, high optical transmission performance, reliability, heat resistance, and durability. Excellent in versatility. Therefore, by providing the optical waveguide structure of the present invention, various highly reliable electronic parts and electronic devices can be obtained.

It is sectional drawing which shows 1st Embodiment of the optical waveguide structure of this invention. It is a perspective view of the optical waveguide shown in FIG. It is a top view which shows 1st Embodiment of the optical waveguide structure of this invention. It is a top view which shows 2nd Embodiment of the optical waveguide structure of this invention. It is a top view which shows 3rd Embodiment of the optical waveguide structure of this invention. It is a top view which shows 4th Embodiment of the optical waveguide structure of this invention. It is sectional drawing which shows 5th Embodiment of the optical waveguide structure of this invention. It is sectional drawing which shows typically the process example of the 1st manufacturing method of an optical waveguide. It is sectional drawing which shows typically the process example of the 1st manufacturing method of an optical waveguide. It is sectional drawing which shows typically the process example of the 1st manufacturing method of an optical waveguide. It is a figure which shows typically the measuring method of the bending loss in an Example.

  Hereinafter, the optical waveguide structure and electronic device of the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.

<First embodiment: FIGS. 1 to 3>
1 is a sectional view showing a first embodiment of the optical waveguide structure of the present invention, FIG. 2 is a perspective view of the optical waveguide shown in FIG. 1, and FIG. 3 is a first embodiment of the optical waveguide structure of the present invention. It is a top view which shows a form. In the following description, the upper side in FIG. 1 is “upper” and the lower side is “lower”. 1 and 2 are exaggerated in the layer thickness direction (vertical direction in each figure).

  As shown in FIG. 1, an optical waveguide structure 1 of the present invention includes a substrate 2, a conductor layer 5 provided on the lower surface of the substrate 2, a light emitting element 3 and a light receiving element 4 provided on the substrate 2, An optical waveguide 9 provided between the light emitting part 31 of the light emitting element 3 and the light receiving part 41 of the light receiving element 4 is provided.

  The optical waveguide 9 is formed by laminating a clad layer (lower clad layer) 91, a core layer 93, and a clad layer (upper clad layer) 92 in this order from the lower side in FIG. A core portion 94 and a clad portion 95 having a predetermined pattern are formed. The core portion 94 is a portion that forms an optical path of the transmission light, and the cladding portion 95 does not form an optical path of the transmission light although it is formed in the core layer 93 and performs the same function as the cladding layers 91 and 92. Part.

  As a constituent material of the core layer 93, a material whose refractive index changes by irradiation with light (for example, ultraviolet rays) or by further heating is used. Preferable examples of such materials include those containing a resin composition containing a cyclic olefin resin such as a benzocyclobutene polymer and a norbornene polymer (resin) as a main material, and include a norbornene polymer (mainly The material) is particularly preferred.

  The core layer 93 made of such a material is excellent in resistance to deformation such as bending, and even when it is repeatedly curved and deformed, the core layer 94 and the clad portion 95 are separated from each other, and the layer adjacent to the core layer 93 ( The delamination with the clad layers 91 and 92) hardly occurs, and the occurrence of microcracks in the core portion 94 and the clad portion 95 is also prevented. As a result, the optical transmission performance of the optical waveguide 9 is maintained, and the optical waveguide 9 having excellent durability is obtained.

  Examples of the constituent material of the core layer 93 include an antioxidant, a refractive index adjuster, a plasticizer, a thickener, a reinforcing agent, a sensitizer, a leveling agent, an antifoaming agent, an adhesion aid, and a flame retardant. The additive may be contained. Addition of an antioxidant has the effect of improving high temperature stability, improving weather resistance, and suppressing light deterioration. Examples of such an antioxidant include phenols such as monophenols, bisphenols, and triphenols, and aromatic amines. Further, the resistance to bending can be further increased by adding a plasticizer, a thickener, and a reinforcing agent.

  The content of additives typified by the antioxidant (the total in the case of two or more) is preferably about 0.5 to 40% by weight, and 3 to 30% by weight with respect to the entire constituent material of the core layer 93. The degree is more preferable. If this amount is too small, the function of the additive cannot be sufficiently exhibited. If the amount is too large, the transmittance of light (transmitted light) transmitted through the core portion 94 depends on the type and characteristics of the additive. Decrease, patterning failure, refractive index instability and the like.

  An example of a method for forming the core layer 93 is a coating method. Examples of the coating method include a method in which a core layer forming composition (varnish or the like) is applied and cured (solidified), and a method in which a curable monomer composition is applied and cured (solidified). In addition, a method other than the coating method, for example, a method of joining separately manufactured sheet materials may be employed.

  The core layer 93 obtained as described above is selectively irradiated with light (active radiation) using a mask to pattern the core portion 94 having a desired shape.

Examples of light used for exposure include active energy rays such as visible light, ultraviolet light, infrared light, and laser light. Further, instead of using light, electromagnetic waves such as X-rays or particle beams such as electron beams may be used.

In the core layer 93, the portion irradiated with light has a lower refractive index, and a difference in refractive index occurs between the portion not irradiated with light. For example, a portion of the core layer 93 that is irradiated with light becomes the cladding portion 95, and a portion that is not irradiated becomes the core portion 94. The refractive index of the cladding part 95 is substantially equal to the refractive index of the cladding layers 91 and 92.

Moreover, the core part 94 may be formed by irradiating the core layer 93 with light in a predetermined pattern and then heating. By adding this heating step, the difference in refractive index between the core portion 94 and the cladding portion 95 becomes larger, which is preferable. This principle will be described later in detail.

  The pattern shape of the core portion 94 to be formed is not particularly limited, and is a straight shape, a shape having a curved portion, an irregular shape, a shape having a branching portion of a light path, a merging portion or a crossing portion, a condensing portion (a width etc. is reduced). Or a light diffusing part (a part where the width or the like is increased), or a combination of two or more of these. A feature of the present invention is that the core portion 94 having any shape can be easily formed by setting the light irradiation pattern.

  The constituent material of each part of the optical waveguide 9 and the method of forming the core part 94 will be described in detail later.

The substrate 2 is a flexible substrate having flexibility and insulation.
Examples of the constituent material of the substrate 2 include epoxy resin, phenol resin, bismaleimide resin, bismaleimide / triazine resin, triazole resin, polycyanurate resin, polyisocyanurate resin, benzocyclobutene resin, polyimide resin, and polybenzoxazole. Examples thereof include resins and norbornene resins. These materials may be used alone or in combination.

  Moreover, the board | substrate 2 may be a laminated body of a some layer. For example, a first layer and a second layer made of a resin material having the same composition (kind) are laminated, and a first layer and a second layer made of resin materials having different compositions (kinds) are laminated. The thing which was done is mentioned. In addition, it cannot be overemphasized that the layer structure in a laminated body is not limited to this.

  Although the thickness of the board | substrate 2 is not specifically limited, Usually, it is preferable that it is about 5-50 micrometers, and it is more preferable that it is about 10-40 micrometers. If the thickness of the substrate 2 is within the above range, the optical waveguide structure 1 has sufficient flexibility.

  The flexibility of the substrate 2 is, for example, such that it can be easily bent by a human hand. Specifically, the Young's modulus (tensile modulus) of the substrate 2 is preferably about 1 to 20 GPa and more preferably about 2 to 12 GPa in a general room temperature environment (around 20 to 25 ° C.). preferable.

  Each of the conductor layers 5 bonded to the lower surface of the substrate 2 is patterned into a predetermined shape to constitute a desired wiring or circuit. That is, the substrate 2 and the conductor layer 5 constitute a wiring board. Examples of the constituent material of the conductor layer 5 include various metal materials such as copper, a copper-based alloy, aluminum, and an aluminum-based alloy. Although the thickness of the conductor layer 5 is not specifically limited, Usually, about 3-120 micrometers is preferable and about 5-70 micrometers is more preferable.

  The conductor layer 5 is formed, for example, by a method such as metal foil bonding (adhesion), metal plating, vapor deposition, or sputtering. For patterning on the conductor layer 5, for example, methods such as etching, printing, masking, etc. can be used.

  In addition, as a wiring board comprised by the board | substrate 2 and the conductor layer 5, copper-clad film board | substrates, such as a polyester copper-clad film board | substrate, a polyimide copper-clad film board | substrate, an aramid copper-clad film board | substrate, glass cloth, epoxy copper, for example Examples thereof include a glass substrate copper clad laminate such as a tension laminate and a composite copper clad laminate such as a glass nonwoven fabric / epoxy copper clad laminate.

  On the other hand, a through hole 21 is formed in the substrate 2, and the through hole 21 is filled with a conductive material (for example, various metal materials such as copper, copper alloy, aluminum, aluminum alloy, etc.), and a conductor post. 22 is provided. The conductor post 22 electrically connects the conductor layer 5 and the upper surface side of the substrate 2.

  The conductor post 22 may be composed of a conductor layer formed on the inner surface of the through hole 21. In this case, the conductor post 22 may be formed on the inner surface of the through hole 21 by various film forming methods such as plating, and may not fill the through hole 21.

  The light emitting element 3 includes a base 30, a light emitting unit 31 fixed to the surface of the base 30, a metal wire 32 connecting the electrode pad of the light emitting unit 31 and the electrode pad of the base 30, An external electrode 33 is provided on the lower surface for connecting the light emitting unit 31 to an external circuit.

When the external electrode 33 is energized, the light emitting unit 31 emits light.
The light emitting element 3 is mounted on the substrate 2 such that the external electrode 33 is joined (electrically connected) to the conductor post 22.

  On the other hand, the light receiving element 4 includes a base 40, a light receiving part 41 fixed to the surface of the base 40, a metal wire 42 connecting the electrode pad of the light receiving part 41 and the electrode pad of the base 40, and a base 40, and has an external electrode 43 for connecting the light receiving unit 41 to an external circuit.

  When the light receiving unit 41 receives an optical signal, it is converted into an electric signal and output from the external electrode 43.

  The light receiving element 4 is mounted on the substrate 2 such that the external electrode 43 is joined (electrically connected) to the conductor post 22.

  The light emitting unit 31 in the light emitting element 3 and the light receiving unit 41 in the light receiving element 4 may each be composed of one light emitting point or one light receiving point, or may be a group of a plurality of light emitting points or light receiving points. . As a collection of a plurality of light emitting points or light receiving points, for example, light emitting points or light receiving points are arranged in a row (for example, 1 × 4 light emitting points or 1 × 12 light emitting points or light receiving points) or a matrix (for example, light emitting points or light receiving points). Examples include n × m light receiving points: n and m are integers of 2 or more, and a plurality of light emitting points or light receiving points arranged randomly (irregularly).

  The optical waveguide 9 is provided between the light emitting element 3 and the light receiving element 4 so as to connect the light emitting point of the light emitting unit 31 and the light receiving point of the light receiving unit 41. Thereby, the light emitting point and the light receiving point are optically connected by the optical waveguide 9.

  The core portion 94 of the optical waveguide 9 is formed in a pattern shape that overlaps each light emitting point and each light receiving point in a plan view (when viewed from above in FIG. 1). The core portion 94 has a higher refractive index than that of the cladding portion 95 and has a higher refractive index than the cladding layers 91 and 92. The clad layers 91 and 92 constitute the clad portions located at the lower part and the upper part of the core part 94, respectively. With such a configuration, as shown in FIG. 2, the core portion 94 functions as a light guide path surrounded by the clad portion on the entire outer periphery.

  The optical waveguide 9 shown in FIG. 2 has one core portion 94, but the number of core portions 94 formed in one optical waveguide 9 is, for example, light emission provided in one light emitting portion 31. It is set according to the number of points and the number of light receiving points provided in one light receiving unit 41 and is not particularly limited.

  The substrate 2 and the conductor layer 5, the optical waveguide 9, the light emitting element 3, the light receiving element 4, and the like mounted on the surface thereof are often handled as one integrated component (optical wiring 98). This is because the optical wiring 98 can be provided to function as a module that can easily perform optical communication between any two points.

  In the optical waveguide structure 1 of the present embodiment, when the external electrode 33 of the light emitting element 3 is energized through the conductor layer 5 and the conductor post 22, the light emitting point of the light emitting portion 31 emits light, and the right side in FIG. The light emitted toward the light enters the core portion 94 of the optical waveguide 9. The optical waveguide 9 repeats reflection at the interface between the core portion 94 and the clad portion (the clad layers 91 and 92 and the side clad portion 95), and the inside of the core portion 94 is in the longitudinal direction (right direction in FIG. 1). Proceed along. When the light reaches the light receiving point of the light receiving unit 41, the light signal is converted into an electric signal in the light receiving unit 41 and output from the external electrode 43.

  Here, the optical waveguide structure 1 shown in FIGS. 1 and 3 is provided so as to cover the optical wiring 98 and has a coating layer 7 made of a flame retardant material.

  The flame retardant constituting the coating layer 7 is a material having high heat resistance, and protects the optical wiring 98 from heat and flame. Moreover, since the coating layer 7 has a function of blocking the optical wiring 98 from the outside air, the optical wiring 98 is protected from deterioration and deterioration of the outside air due to moisture.

  Examples of the flame retardant include a polyimide resin, a polyamide resin, a silicone resin, an epoxy resin, and the like, and one or more of these can be used in combination.

  Of these, polyimide resins and polyamide resins are particularly preferable. These resin materials are particularly excellent in heat resistance and are less likely to generate substances that adversely affect the optical wiring 98 due to heat. For this reason, it is suitable as a flame retardant constituting the coating layer 7.

  The polyimide resin is a resin having an imide ring as a repeating unit. Specifically, it is roughly divided into wholly aromatic polyimides, semi-aromatic polyimides, and thermosetting polyimides, and any of these is used as a flame retardant.

  Examples of the polyimide resin include polyimide, polyamideimide, polyesterimide, and polyetherimide.

  The number average molecular weight of the polyimide resin is preferably about 10,000 to 200,000, more preferably about 20,000 to 100,000. Thereby, the polyimide-type resin which can be compatible with the ease of handling at the time of forming the coating layer 7 and heat resistance is obtained.

  In addition, modified polyimide resins obtained by modifying polyimide for various purposes are also used as the polyimide resins. Examples of such modified polyimide resins include siloxane-modified polyimide resins, carbonate-modified polyimide resins, fluorine-modified polyimides, urethane-modified polyimides, triazine-modified polyimides, phenol-modified polyimides, and the like.

  On the other hand, the polyamide-based resin is a resin having an amide bond as a repeating unit. Specifically, it is roughly classified into aliphatic polyamides composed of aliphatic chains, aromatic polyamides composed of aromatic skeletons, and the like. From the polymerization method, polyamides and lactams obtained by polycondensation of diamine and dibasic acid are developed. Polyamides obtained by ring polymerization, polyamides obtained by polycondensation of aminocarboxylic acids, and the like are roughly classified. Any of these is used as a flame retardant.

  Among these, aliphatic polyamide is synthesized by copolymerization reaction of aliphatic diamine and carboxylic acid, and examples thereof include nylon 66, nylon 610, nylon 6T, nylon 6I, nylon 9T, nylon M5T and the like.

  An aromatic polyamide is synthesized by a copolymerization reaction of an aromatic diamine and a dicarboxylic acid. For example, a copolymer of p-phenylenediamine and terephthalic acid, or a copolymer of m-phenylenediamine and isophthalic acid. Etc. Aromatic polyamides are particularly suitable as flame retardants because of their excellent heat resistance.

  The number average molecular weight of the polyamide-based resin is preferably about 5,000 to 100,000, and more preferably about 10,000 to 80,000. Thereby, the polyamide-type resin which can be highly compatible with the ease of handling at the time of forming the coating layer 7, and heat resistance is obtained.

  In addition to silicone resins such as dimethylpolysiloxane, methylphenylpolysiloxane, and diphenylpolysiloxane, these silicone resins can be used for modifying alkyd resins, polyester resins, acrylic resins, epoxy resins, and the like. Examples include modified silicone resins that have been reacted with a resin.

  Moreover, as an epoxy resin, a novolak-type epoxy resin, a polyfunctional group epoxy resin, an alicyclic epoxy resin etc. are mentioned, for example.

  Further, as the flame retardant constituting the coating layer 7, in addition to the above, acrylonitrile / butadiene / styrene copolymer resin (ABS) polystyrene, polyetherimide, polyphenylene sulfide, polyetheretherketone, polyamideimide, polybutylene terephthalate Even various resin materials such as (PBT), polycarbonate (PC), and modified polyphenylene ether (M-PPE) include halogen compounds such as fluorine compounds, chlorine compounds, bromine compounds, and phosphorus compounds. Good.

Among these, as the compound to be added, a chlorine compound, a bromine compound, and a phosphorus compound are preferably used. Specifically, chlorinated paraffin and the like are preferably used as the chlorine compound, pentabromodiphenyl ether and octabromodiphenyl ether as the bromine compound, and triphenyl phosphate and red phosphorus as the phosphorus compound. In addition, even if these compounds are added to the polyimide resin, polyamide resin, silicone resin, and epoxy resin described above, they contribute to an increase in the flame-retardant effect.
The resin material as described above may contain a flame retardant filler.

  Examples of the flame retardant filler include various inorganic fillers such as titanium oxide, silicon oxide (silica), aluminum oxide, mica (mica), talc, and glass. These act to further increase the heat resistance of the flame retardant.

  Among the inorganic fillers, the glass filler is composed of, for example, E glass, S glass, A glass, C glass, L glass, D glass, high elastic modulus glass, silica, glass powder, low melting point glass, and the like. A glass filler is mentioned. Moreover, as a form of a glass filler, a chopped strand, a milled fiber, etc. are mentioned, for example.

  When the filler is added to the flame retardant, the amount added is preferably 1 part by weight or more and 80 parts by weight or less, and preferably 5 parts by weight or more and 70 parts by weight or less with respect to 100 parts by weight of the resin material. More preferred.

  The coating layer 7 composed of such a flame retardant is desired to have as high a flame retardant performance as possible. Specifically, the flame retardant property is determined by a UL 94 test, which is one of the UL combustion test methods. It is preferably HB or more. Since the coating layer 7 has such flame retardancy, the function of the optical wiring 98 can be maintained for a long time even if an electronic component or the like that can be a heating element is located near the optical wiring 98. it can. As a result, the long-term reliability of the optical waveguide structure 1 can be improved.

The UL94 test is performed as follows.
First, a strip-shaped test piece is prepared. For example, the test piece has a width of 13 mm, a length of 125 mm, and a thickness of 100 μm.

  Next, in a vertical combustion test or a horizontal combustion test, a flame of a gas burner is applied to the test piece to examine the degree of combustion of the test piece. Then, it is determined which class of flame retardancy corresponds to whether or not the combustion state of the test piece satisfies a predetermined condition.

  The flame retardant class includes 5VA, 5VR, V-0, V-1, V-2, and HB in descending order of flame retardancy. The flame retardancy of the coating layer 7 is preferably a class of HB or higher, and is preferably a class of V-2 or higher.

  The average thickness of the coating layer 7 is preferably about 10 to 200 μm, more preferably about 20 to 100 μm. By setting the thickness of the coating layer 7 within the above range, necessary and sufficient flame retardancy is imparted to the coating layer 7 without significantly impairing the flexibility of the optical wiring 98. As a result, the long-term reliability of the optical waveguide structure 1 can be further improved.

  Such a coating layer 7 is formed by applying the liquid material before solidification of the flame retardant material described above, and then solidifying (curing) it.

  For the application of the resin material, a supply device such as a dispenser, spray, screen printing, roll coating, curtain coating or the like is used in addition to a method of immersing the optical wiring 98 in the liquid material. In order to use such a method or apparatus, a certain degree of fluidity is required for the liquid material. Specifically, the viscosity of the liquid material is preferably about 1 to 30 Pa · s, and more preferably about 2 to 20 Pa · s.

  The applied liquid material is solidified according to the composition of the liquid material, but is left at room temperature, heated, or irradiated with energy rays such as ultraviolet rays.

  Moreover, when preparing a liquid material, you may make it add a solvent as needed. The viscosity of the liquid material can be adjusted by adding a solvent. Examples of the solvent include diethyl ether, diisopropyl ether, 1,2-dimethoxyethane (DME), 1,4-dioxane, tetrahydrofuran (THF), tetrahydropyran (THP), anisole, diethylene glycol dimethyl ether (diglyme), diethylene glycol ethyl ether. (Cerbitol) ether solvents, methyl cellosolve, ethyl cellosolve, cellosolve solvents such as phenyl cellosolve, aliphatic hydrocarbon solvents such as hexane, pentane, heptane, cyclohexane, aromas such as toluene, xylene, benzene, mesitylene Aromatic hydrocarbon solvents, pyridine, pyrazine, furan, pyrrole, thiophene, methylpyrrolidone and other aromatic heterocyclic compounds solvents, N, N-dimethylformamide (DMF) Amide solvents such as N, N-dimethylacetamide (DMA), halogen compound solvents such as dichloromethane, chloroform and 1,2-dichloroethane, ester solvents such as ethyl acetate, methyl acetate and ethyl formate, dimethyl sulfoxide (DMSO) ), Various organic solvents of sulfur compound solvents such as sulfolane, or mixed solvents containing these.

  In addition, when using a solvent, it is preferable to use the quantity about 0.5-10 times of the said resin material by mass ratio, and it is preferable to use the quantity about 1-8 times. Thereby, while making the viscosity of a liquid material into the viscosity suitable for application | coating operation | work, it can prevent that the speed | rate of a solidification reaction falls remarkably.

  Such an optical waveguide structure 1 has excellent heat resistance and durability because the optical wiring 98 is covered with the coating layer 7 made of a flame retardant. In particular, since the optical waveguide 9, the substrate 2, and the conductor layer 5 have low heat resistance, it is possible to reliably prevent the function of the optical waveguide structure 1 from being lost by covering them with the coating layer 7.

  Moreover, since various resin materials are used as the flame retardant, there is little risk of hindering the flexibility of the optical wiring 98, and excellent flexibility can be imparted to the optical waveguide structure 1. Such an optical waveguide structure 1 does not break even if the bending operation is repeated, and has excellent bending resistance.

  Further, by providing the covering layer 7, each component of the optical wiring 98 can be fixed from the outside. As a result, the optical waveguide structure 1 is given durability against external force, for example, a function of preventing the component parts from being damaged or dropped by the external force.

Second Embodiment: FIG. 4
FIG. 4 shows a second embodiment of the optical waveguide structure 1 of the present invention. Hereinafter, although this optical waveguide structure 1 is demonstrated, the description is abbreviate | omitted about the matter similar to the said 1st Embodiment, and it demonstrates centering around difference.
FIG. 4 is a plan view of the second embodiment.

  The optical waveguide structure 1 of this embodiment is different from the above in the configuration of the optical waveguide 9, the light emitting element 3, and the light receiving element 4, and is otherwise the same.

  That is, three optical waveguides 9, light emitting elements 3, and light receiving elements 4 are provided on one substrate 2. Thereby, since optical communication can be performed by the three optical waveguides 9 in parallel, the capacity of the optical communication of the optical waveguide structure 1 can be increased.

<Third Embodiment: FIG. 5>
FIG. 5 shows a third embodiment of the optical waveguide structure 1 of the present invention. Hereinafter, although this optical waveguide structure 1 is demonstrated, the description is abbreviate | omitted about the matter similar to the said 1st Embodiment, and it demonstrates centering around difference.
FIG. 5 is a plan view of the third embodiment.

  The optical waveguide structure 1 of this embodiment is different from the above in the configuration of the optical waveguide 9, the light emitting element 3, and the light receiving element 4, and is otherwise the same.

  That is, three optical waveguides 9, a light emitting element 3 having a light emitting part 31 having three light emitting points, and a light receiving element 4 having a light receiving part 41 having three light receiving points are provided on one substrate 2. It has been. Thereby, since optical communication can be performed by the three optical waveguides 9 in parallel, the capacity of the optical communication of the optical waveguide structure 1 can be increased. Moreover, since the number of parts can be reduced compared with the case of FIG. 4, the structure of the optical waveguide structure 1 can be simplified and the number of steps in the manufacturing process can be reduced.

<Fourth Embodiment: FIG. 6>
FIG. 6 shows a fourth embodiment of the optical waveguide structure 1 of the present invention. Hereinafter, although this optical waveguide structure 1 is demonstrated, the description is abbreviate | omitted about the matter similar to the said 1st Embodiment, and it demonstrates centering around difference.
FIG. 6 is a plan view of the fourth embodiment.

  The optical waveguide structure 1 of this embodiment is different from the above in the configuration of the optical waveguide 9, the light emitting element 3, and the light receiving element 4, and is otherwise the same.

  That is, one optical waveguide 9 in which three core portions 94 are formed on one substrate 2, a light emitting element 3 having a light emitting portion 31 having three light emitting points, and a light receiving portion 41 having three light receiving points. Is provided. Thereby, since optical communication can be performed by the three optical waveguides 9 in parallel, the capacity of the optical communication of the optical waveguide structure 1 can be increased. Moreover, since the number of parts can be further reduced as compared with the case of FIG. 5, the structure of the optical waveguide structure 1 can be simplified and the number of steps in the manufacturing process can be reduced.

<Fifth Embodiment: FIG. 7>
FIG. 7 shows a fifth embodiment of the optical waveguide structure 1 of the present invention. Hereinafter, although this optical waveguide structure 1 is demonstrated, the description is abbreviate | omitted about the matter similar to the said 1st Embodiment, and it demonstrates centering around difference.
FIG. 7 is a cross-sectional view of the fifth embodiment.

  The optical waveguide structure 1 of the present embodiment is different from the above in the configuration of the substrate 2, the optical waveguide 9, the light emitting element 3, and the light receiving element 4, and is otherwise the same.

  That is, the substrate 2 shown in FIG. 7 is provided only in the vicinity of both ends in the longitudinal direction of the optical waveguide structure 1 (optical wiring 98). Specifically, the substrates 2 are laminated on the upper surfaces of both end portions of the optical waveguide 9.

  In addition, a conductor layer 5 on which electrical wiring is formed is provided on the upper surface of the substrate 2, and a light emitting element 3 and a light receiving element 4 are mounted thereon.

  The substrate 2 may be the flexible substrate described in the first embodiment, but may be a rigid rigid substrate. By using the substrate 2 as a rigid substrate, the rigidity of both ends of the optical waveguide structure 1 on which the light-emitting element 3 and the light-receiving element 4 are mounted is increased, and the light-emitting element 3 and the light-receiving element 4 are prevented from being damaged or dropped due to bending. The

  Further, on the substrate 2 (first support member) on the left side of FIG. 7, a surface mount type light emitting element 3 and a light emitting IC (driving circuit) 35 for driving light emission of the light emitting element 3 are mounted. ing. The light emitting element 3 and the light emitting IC 35 are electrically connected via the conductor layer 5. Thereby, the light emission of the light emitting element 3 can be controlled by the light emitting IC 35. That is, a light emitting circuit (light transmitting unit) 300 including the light emitting element 3 and the light emitting IC 35 is constructed on the left substrate 2.

On the other hand, on the substrate 2 (second support member) on the right side of FIG. 7, a surface mount type light receiving element 4 and a light receiving IC (amplifying circuit) 45 for amplifying a signal received by the light receiving element 4 are provided. It is installed. The light receiving element 4 and the light receiving IC 45 are electrically connected through the conductor layer 5. Thus, the light receiving element 4 receives the light and converts it into an electric signal, which is then input to the light receiving IC 45. That is, a light receiving circuit (light receiving unit) 400 including the light receiving element 4 and the light receiving IC 45 is constructed on the right substrate 2.
As described above, optical communication is performed between the light emitting circuit 300 and the light receiving circuit 400.

  The two substrates 2 are provided with through holes 23 in accordance with the position of the light emitting part 31 of the light emitting element 3 and the position of the light receiving part 41 of the light receiving element 4.

  Further, in the optical waveguide 9, optical path conversion portions 97 are respectively formed at positions corresponding to the positions immediately below the respective through holes 23.

  Each optical path changing portion 97 has a sloped surface that is inclined by approximately 45 ° with respect to the axis of the core portion 94 of the optical waveguide 9 by removing part of the optical waveguide 9. Formed. The inclined surface reflects the light from the light emitting unit 31 at an angle of 90 ° so as to guide the light to the core portion 94 or reflects the light propagated through the core portion 94 at an angle of 90 ° so as to guide the light to the light receiving portion 41. It functions as a reflective surface.

  Each through hole 23 functions as an optical signal passage region that guides light from the light emitting unit 31 to the optical path conversion unit 97 and guides light from the optical path conversion unit 97 to the light receiving unit 41.

The light emitting unit 31 and the light receiving unit 41 are optically connected by the two optical path changing units 97 and the two optical signal passing regions (through holes 23) as described above.
Each optical path conversion unit 97 is formed in the middle of the optical waveguide 9 in the longitudinal direction.

  Here, in the longitudinal direction of the optical waveguide 9, the left side of the optical path conversion unit 97 located on the left side in FIG. 7 is made of a material obtained by carbonizing the constituent material of the optical waveguide 9 (carbonized material). Since the region on the left side of the optical path conversion unit 97 located on the left side in FIG. 7 is a region that is not optically connected to the optical path conversion unit 97, the optical waveguide structure 1 However, it functions as a shield that prevents outside light and stray light from entering the optical path changing unit 97 and the core unit 94. For this reason, the optical transmission efficiency of the optical waveguide structure 1 can be increased by configuring the region with the carbonized material.

  The left region of the optical path conversion unit 97 has the above-described effects as long as at least a part thereof is made of a carbonized material. Preferably, the entire region is made of a carbonized material. Thereby, since the shielding function mentioned above improves especially, the optical transmission efficiency of the optical waveguide structure 1 can be raised especially.

  In order to configure the left region of the optical path changing unit 97 with the carbonized material, the optical waveguide 9 can be manufactured by using the above-described polymer, and then the region can be burned.

  This combustion (carbonization treatment) is generally performed in an environment having a low oxygen concentration. As a result, hydrocarbons in the polymer are carbonized, and a substance (carbonized material) containing carbon as a main component remains. When the carbonization is completed, such a carbonized material is produced. This carbonized material generally exhibits a black color or a similar color, and thus has a high light absorption capability. For this reason, the shielding function mentioned above will surely appear.

  By the carbonization treatment as described above, the region on the left side of the optical path conversion unit 97 is constituted by a carbonized material obtained by carbonizing the core portion 94 and the cladding portion 95 and the cladding layers 91 and 92 covering the core portion 94.

  On the other hand, the region on the left side of the optical path changing portion 97 is preferably composed only of a material obtained by carbonizing the clad portion 95 or the clad layers 91 and 92, that is, only a material obtained by carbonizing the clad material. Thereby, since this region is composed of carbonized materials having a single composition or a similar composition among the carbonized materials, the above-described shielding function becomes particularly remarkable.

  In order to configure the left region of the optical path conversion unit 97 only with a material obtained by carbonizing the cladding material, it is necessary to prepare an optical waveguide 9 in which the region is configured only with the cladding material prior to the carbonization process. . For example, when the core layer 93 is formed, such an optical waveguide 9 irradiates the entire region with light or does not emit light at all, depending on the constituent material of the core layer 93. Good. Thereby, the said area | region will be comprised only with a clad material.

  By subjecting the region of the optical waveguide 9 obtained in this way to the carbonization described above, the region can be formed only of a material obtained by carbonizing the cladding material.

  The carbonization treatment may be performed on any surface as long as the core portion 94 is not exposed on the surface of the optical waveguide 9, and may be performed on the entire surface of the optical waveguide 9 if conditions are met. May be. Thereby, the effect of the stray light entering the core portion 94 being reliably suppressed can be expected.

  The substrate 2, the conductor layer 5, the optical waveguide 9, the light emitting element 3, the light receiving element 4 and the like as described above constitute an optical wiring 98 as in the first embodiment. The optical waveguide structure 1 has a coating layer 7 provided so as to cover the optical wiring 98.

  The configuration of the coating layer 7 is the same as that of the first embodiment, and acts to impart heat resistance and durability to the optical waveguide structure 1.

  Moreover, since the optical wiring 98 according to the present embodiment is composed of only the optical waveguide 9 and the coating layer 7 at the center in the longitudinal direction, the optical wiring 98 has particularly high flexibility, excellent ease of bending, and bend resistance. Also excellent.

  Furthermore, since the optical waveguide 9 is not in contact with other members other than the covering layer 7 in this central portion, the optical waveguide 9 is prevented from being deformed regardless of whether it is bent or not, and the light transmission efficiency is prevented from being lowered. Is done.

  In addition, although the form which covers the whole optical wiring 98 with the coating layer 7 was demonstrated above, this invention is not limited to this form, The coating layer 7 is covered so that only the surface of the optical waveguide 9 with especially low heat resistance may be covered. It may be provided. Further, depending on the heat resistance performance of each element, either the light emitting element 3 or the light receiving element 4 may be exposed, and either the light emitting IC 35 or the light receiving IC 45 may be exposed. Thereby, since the heat dissipation of each element improves compared with the case where it covers with the coating layer 7, the malfunctioning by the self-heating and failure can be prevented.

  The first to fifth embodiments have been described above, but the present invention is not limited to these, and other configurations may be used as long as the gist of the invention is not changed. Further, the present invention may be a combination of configurations included in any two or more of the first to fifth embodiments.

  The electronic device to which the optical waveguide structure of the present invention is applied is preferably applied to electronic devices such as a mobile phone, a game machine, a PDA, a router device, a WDM device, a personal computer, a television, and a home server. is there. In any of these electronic devices, it is necessary to transmit a large amount of data at high speed between an arithmetic device such as an LSI and a storage device such as a RAM. Therefore, since such an electronic device includes the optical waveguide structure according to the present invention, problems such as noise and signal degradation peculiar to electric wiring are eliminated, and a dramatic improvement in performance can be expected.

  In addition, the amount of heat generated in the optical waveguide portion is greatly reduced compared to electrical wiring. Therefore, the degree of integration in the substrate can be increased to reduce the size, the power required for cooling can be reduced, and the power consumption of the entire electronic device can be reduced.

<Optical waveguide manufacturing method>
Next, the manufacturing method of the optical waveguide 9 and the constituent materials of each part in each of the above embodiments will be described. In particular, the method for forming the core part 94 will be described in detail.

  First, prior to the description of the method for forming the core portion 94, the photosensitive resin composition used for forming the core portion 94 will be described.

(Photosensitive resin composition)
The photosensitive resin composition used in this embodiment is
(A) a cyclic olefin resin;
(B) The refractive index is different from (A), and at least one of a monomer having a cyclic ether group and an oligomer having a cyclic ether group;
(C) a photoacid generator;
Is provided.

Among these, from the viewpoint of reliably suppressing the occurrence of light propagation loss,
(C) a cyclic olefin resin (A) having a leaving group capable of leaving by an acid generated from a photoacid generator in the side chain;
It is preferable to contain the monomer of following formula (100).

  Such a photosensitive resin composition is formed into a film to be an optical waveguide forming film, and further used as a film including regions having different refractive indexes, for example, an optical waveguide film.

  That is, by using such a photosensitive resin composition, it is possible to provide an optical waveguide film or the like in which the occurrence of light propagation loss is suppressed. In particular, when a curved optical waveguide is formed, generation of light propagation loss can be remarkably suppressed.

  Furthermore, an optical / electrical hybrid substrate including an optical wiring using such an optical waveguide film, the optical wiring, and an electric circuit can be provided. According to such an optical wiring and an opto-electric hybrid board, it is possible to improve EMI (electromagnetic wave interference), which has been a problem with the conventional electrical wiring, and the signal transmission speed can be greatly improved as compared with the conventional one.

  In addition, an electronic device using the optical waveguide film can be provided. By using the optical waveguide film, space saving can be achieved, which contributes to downsizing of electronic devices.

  Specific examples of such an electronic device include a computer, a server, a mobile phone, a game device, a memory tester, and an appearance inspection robot.

Hereinafter, the components of the photosensitive resin composition will be described in detail.
((A) Cyclic olefin resin)
The cyclic olefin resin of component (A) is added in order to ensure the film moldability of the photosensitive resin composition, and serves as a base polymer.

  Here, the cyclic olefin resin may be unsubstituted, or hydrogen may be substituted with another group.

  Examples of the cyclic olefin resin include norbornene resins and benzocyclobutene resins.

  Especially, it is preferable to use norbornene-type resin from viewpoints, such as heat resistance and transparency.

As norbornene resin, for example,
(1) addition (co) polymer of norbornene type monomer obtained by addition (co) polymerization of norbornene type monomer,
(2) an addition copolymer of a norbornene monomer and ethylene or α-olefins,
(3) an addition polymer such as an addition copolymer of a norbornene-type monomer and a non-conjugated diene and, if necessary, another monomer;
(4) a ring-opening (co) polymer of a norbornene-type monomer, and a resin obtained by hydrogenating the (co) polymer if necessary,
(5) a ring-opening copolymer of a norbornene-type monomer and ethylene or α-olefins, and a resin obtained by hydrogenating the (co) polymer if necessary,
(6) Ring-opening copolymers such as norbornene-type monomers and non-conjugated dienes, or other monomers, and polymers obtained by hydrogenating the (co) polymers as necessary. Examples of these polymers include random copolymers, block copolymers, and alternating copolymers.

  These norbornene resins include, for example, ring-opening metathesis polymerization (ROMP), combination of ROMP and hydrogenation reaction, polymerization by radical or cation, polymerization using cationic palladium polymerization initiator, other polymerization initiators ( For example, it can be obtained by any known polymerization method such as polymerization using a polymerization initiator of nickel or another transition metal).

  Among these, as the norbornene-based resin, an addition (co) polymer is preferable. Addition (co) polymers are also preferred because they are rich in transparency, heat resistance and flexibility. For example, after forming a film with the photosensitive resin composition, an electrical component or the like may be mounted via solder. In such a case, an addition (co) polymer is preferable because it needs to have high heat resistance, that is, reflow resistance. Further, when a film is formed from the photosensitive resin composition and incorporated in a product, it may be used in an environment of about 80 ° C., for example. Even in such a case, an addition (co) polymer is preferable from the viewpoint of ensuring heat resistance.

  Among them, the norbornene-based resin preferably includes a norbornene repeating unit having a substituent containing a polymerizable group or a norbornene repeating unit having a substituent containing an aryl group.

  As the repeating unit of norbornene having a substituent containing a polymerizable group, the repeating unit of norbornene having a substituent containing an epoxy group, the repeating unit of norbornene having a substituent containing a (meth) acryl group, and an alkoxysilyl group At least one of the repeating units of norbornene having a substituent containing is preferable. These polymerizable groups are preferable because of their high reactivity among various polymerizable groups.

  Moreover, if the thing containing 2 or more types of repeating units of norbornene containing such a polymeric group is used, both flexibility and heat resistance can be aimed at.

  On the other hand, by including a norbornene repeating unit having a substituent containing an aryl group, dimensional change due to water absorption can be more reliably prevented by the extremely high hydrophobicity derived from the aryl group.

  Furthermore, the norbornene-based polymer preferably contains an alkylnorbornene repeating unit. The alkyl group may be linear or branched.

  By including the repeating unit of alkyl norbornene, the norbornene-based polymer has high flexibility, and thus can provide high flexibility (flexibility).

  A norbornene-based polymer containing an alkylnorbornene repeating unit is also preferable because of its excellent transmittance with respect to light in a specific wavelength region (particularly, a wavelength region near 850 nm).

  Therefore, as the norbornene-based resin, those represented by the following formulas (1) to (4) and (8) to (10) are preferable.

（式（１）中、Ｒ_１は、炭素数１〜１０のアルキル基を表し、ａは、０〜３の整数を表し、ｂは、１〜３の整数を表し、ｐ_１／ｑ_１が２０以下である。）

(In Formula (1), R ₁ represents an alkyl group having 1 to 10 carbon atoms, a represents an integer of 0 to 3, b represents an integer of 1 to 3, and p ₁ / q ₁ is 20 or less.)

The norbornene-based resin of the formula (1) can be produced as follows.
(1) is obtained by dissolving norbornene having R ₁ and norbornene having an epoxy group in the side chain in toluene and solution polymerization using Ni compound (A) as a catalyst.

  In addition, the manufacturing method of norbornene which has an epoxy group in a side chain is as (i) (ii), for example.

(I) Synthesis of norbornene methanol (NB—CH ₂ —OH) CPD (cyclopentadiene) and α olefin (CH ₂ ═CH—CH ₂ —OH) produced by cracking of DCPD (dicyclopentadiene) are heated under high temperature and high pressure. React.

(Ii) Synthesis of epoxy norbornene It is formed by the reaction of norbornene methanol and epichlorohydrin.

  In the formula (1), when b is 2 or 3, an epichlorohydrin in which the methylene group is an ethylene group, a propylene group or the like is used.

Among the norbornene-based resins represented by the formula (1), from the viewpoint that both flexibility and heat resistance can be achieved, in particular, R ₁ is an alkyl group having 4 to 10 carbon atoms, and a and A compound in which each b is 1, for example, a copolymer of butylbornene and methyl glycidyl ether norbornene, a copolymer of hexyl norbornene and methyl glycidyl ether norbornene, a copolymer of decyl norbornene and methyl glycidyl ether norbornene, or the like is preferable.

（式（２）中、Ｒ_２は、炭素数１〜１０のアルキル基を表し、Ｒ_３は、水素原子またはメチル基を表し、ｃは、０〜３の整数を表し、ｐ_２／ｑ_２が２０以下である。）

(In Formula (2), R ₂ represents an alkyl group having 1 to 10 carbon atoms, R ₃ represents a hydrogen atom or a methyl group, c represents an integer of 0 to 3, and p ₂ / q _2. Is 20 or less.)

The norbornene-based resin of the formula (2) is obtained by dissolving norbornene having R ₂ and norbornene having acryl and methacryl groups in the side chain in toluene, and performing solution polymerization using the Ni compound (A) described above as a catalyst. Obtainable.

Among the norbornene-based polymers represented by the formula (2), R ₂ is an alkyl group having 4 to 10 carbon atoms and c is 1 from the viewpoint of achieving both flexibility and heat resistance. Compounds such as copolymers of butylbornene and 2- (5-norbornenyl) methyl acrylate, copolymers of hexylnorbornene and 2- (5-norbornenyl) methyl acrylate, decylnorbornene and 2- (5-norbornenyl) methyl acrylate And a copolymer thereof are preferred.

（式（３）中、Ｒ_４は、炭素数１〜１０のアルキル基を表し、各Ｘ_３は、それぞれ独立して、炭素数１〜３のアルキル基を表し、ｄは、０〜３の整数を表し、ｐ_３／ｑ_３が２０以下である。）

(In Formula (3), R ₄ represents an alkyl group having 1 to 10 carbon atoms, each X ₃ independently represents an alkyl group having 1 to 3 carbon atoms, and d represents 0 to 3 carbon atoms. Represents an integer, and p ₃ / q ₃ is 20 or less.)

The resin of the formula (3) can be obtained by dissolving norbornene having R ₄ and norbornene having an alkoxysilyl group in the side chain in toluene, and solution polymerization using the Ni compound (A) described above as a catalyst. it can.

Among the norbornene-based polymers represented by the formula (3), in particular, a compound in which R ₄ is an alkyl group having 4 to 10 carbon atoms, d is 1 or 2, and X ₃ is a methyl group or an ethyl group, For example, a copolymer of butylbornene and norbornenylethyltrimethoxysilane, a copolymer of hexylnorbornene and norbornenylethyltrimethoxysilane, a copolymer of decylnorbornene and norbornenylethyltrimethoxysilane, butylbornene and triethoxysilylnorbornene Copolymer of hexyl norbornene and triethoxysilyl norbornene, copolymer of decyl norbornene and triethoxysilyl norbornene, copolymer of butylbornene and trimethoxysilyl norbornene, hexyl norbornene And copolymers of trimethoxysilyl norbornene, copolymers, etc. of decyl norbornene and trimethoxysilyl norbornene are preferred.

（式中、Ｒ_５は、炭素数１〜１０のアルキル基を表し、Ａ_１およびＡ_２は、それぞれ独立して、下記式（５）〜（７）で表される置換基を表すが、同時に同一の置換基であることはない。また、ｐ_４／ｑ_４＋ｒが２０以下である。）

(In the formula, R ₅ represents an alkyl group having 1 to 10 carbon atoms, and A ₁ and A ₂ each independently represent a substituent represented by the following formulas (5) to (7), (It is not the same substituent at the same time, and p ₄ / q ₄ + r is 20 or less.)

(4) is obtained by dissolving norbornene having R ₅ and norbornene having A ₁ and A ₂ in the side chain in toluene and solution polymerization using Ni compound (A) as a catalyst.

（式（５）中、ｅは、０〜３の整数を表し、ｆは、１〜３の整数を表す。）

(In formula (5), e represents an integer of 0 to 3, and f represents an integer of 1 to 3.)

（式（６）中、Ｒ_６は、水素原子またはメチル基を表し、ｇは、０〜３の整数を表す。）

(In formula (6), R ₆ represents a hydrogen atom or a methyl group, and g represents an integer of 0 to 3.)

（式（７）中、Ｘ_４は、それぞれ独立して、炭素数１〜３のアルキル基を表し、ｈは、０〜３の整数を表す。）

(Equation (7) in, _{X 4} each independently represents an alkyl group having 1 to 3 carbon atoms, h is. Represents an integer of 0 to 3)

  In addition, as a norbornene-type polymer represented by Formula (4), for example, any of butyl norbornene, hexyl norbornene or decyl norbornene, 2- (5-norbornenyl) methyl acrylate, norbornenyl ethyltrimethoxysilane, Terpolymer with either triethoxysilyl norbornene or trimethoxysilyl norbornene, terpolymer of butylbornene, hexylnorbornene or decylnorbornene, 2- (5-norbornenyl) methyl acrylate and methylglycidyl ether norbornene, butylbornene, Either hexyl norbornene or decyl norbornene and methyl glycidyl ether norbornene, norbornenyl ethyltrimethoxysilane, triethoxysilyl Terpolymers, etc. with either Ruborunen or trimethoxysilyl norbornene.

（式（８）中、Ｒ_７は、炭素数１〜１０のアルキル基を表し、Ｒ_８は、水素原子、メチル基またはエチル基を表し、Ａｒは、アリール基を表し、Ｘ_１は、酸素原子またはメチレン基を表し、Ｘ_２は、炭素原子またはシリコン原子を表し、ｉは、０〜３の整数を表し、ｊは、１〜３の整数を表し、ｐ_５／ｑ_５が２０以下である。）

(In formula (8), R ₇ represents an alkyl group having 1 to 10 carbon atoms, R ₈ represents a hydrogen atom, a methyl group or an ethyl group, Ar represents an aryl group, and X ₁ represents oxygen. X ₂ represents a carbon atom or a silicon atom, i represents an integer of 0 to 3, j represents an integer of 1 to 3, and p ₅ / q ₅ is 20 or less. is there.)

Norbornene having R ₇ and norbornene containing-(CH ₂ ) -X ₁ -X ₂ (R ₈ ) _3-j (Ar) _j in the side chain are dissolved in toluene, and solution polymerization is performed using a Ni compound as a catalyst. (8) is obtained.

Of the norbornene polymers represented by the formula (8), those in which X ₁ is an oxygen atom, X ₂ is a silicon atom, and Ar is a phenyl group are preferable.

Further, particularly from the viewpoint of flexibility, heat resistance and refractive index control, R ₇ is an alkyl group having 4 to 10 carbon atoms, X ₁ is an oxygen atom, X ₂ is a silicon atom, Ar is a phenyl group, R _A compound in which ₈ is a methyl group, i is 1 and j is 2, for example, a copolymer of butylbornene and diphenylmethylnorbornenemethoxysilane, a copolymer of hexylnorbornene and diphenylmethylnorbornenemethoxysilane, decylnorbornene and diphenylmethylnorbornenemethoxysilane Of these, the copolymer is preferred.
Specifically, it is preferable to use the following norbornene resin.

（式（９）におけるＲ_７、ｐ_５、ｑ_５、ｉは、式（８）と同じである。）

(R ₇ , p ₅ , q ₅ , and i in formula (9) are the same as in formula (8).)

From the viewpoint of flexibility, heat resistance, and refractive index control, in Formula (8), R ₇ is an alkyl group having 4 to 10 carbon atoms, X ₁ is a methylene group, X ₂ is a carbon atom, and Ar is Compounds having a phenyl group, R ₈ is a hydrogen atom, i is 0, and j is 1, for example, a copolymer of butylbornene and phenylethylnorbornene, a copolymer of hexylnorbornene and phenylethylnorbornene, a copolymer of decylnorbornene and phenylethylnorbornene Etc.
Further, the following may be used as the norbornene resin.

（式（１０）において、Ｒ_１０は、炭素数１〜１０のアルキル基を表し、Ｒ_１１は、アリール基を示し、ｋは０以上、４以下である。ｐ_６／ｑ_６は２０以下である。）

(In Formula (10), R ₁₀ represents an alkyl group having 1 to 10 carbon atoms, R ₁₁ represents an aryl group, and k is 0 or more and 4 or less. P ₆ / q ₆ is 20 or less. is there.)

P ₁ / q _{1 to} p ₃ / q ₃ , p ₅ / q ₅ , p ₆ / q ₆ or p ₄ / q ₄ + r may be 20 or less, preferably 15 or less, About 0.1-10 is more preferable. Thereby, the effect including the repeating unit of multiple types of norbornene is exhibited.

  The norbornene-based resin as described above preferably has a leaving group. Here, the leaving group is a group that is released by the action of an acid.

  Specifically, those having at least one of an —O— structure, an —Si—aryl structure, and an —O—Si— structure in the molecular structure are preferable. Such an acid leaving group is released relatively easily by the action of a cation.

  Among these, as the leaving group that causes a decrease in the refractive index of the resin by leaving, at least one of the -Si-diphenyl structure and the -O-Si-diphenyl structure is preferable.

For example, among the norbornene polymers represented by the formula (8), those in which X ₁ is an oxygen atom, X ₂ is a silicon atom, and Ar is a phenyl group have a leaving group.

In the formula (3), there is a case where the Si—O—X ₃ part of the alkoxysilyl group is eliminated.

  For example, when the norbornene resin of formula (9) is used, it is presumed that the reaction proceeds as follows by the acid generated from the photoacid generator (denoted as PAG). Here, only the leaving group portion is shown, and the case where i = 1 is described.

Furthermore, in addition to the structure of the formula (9), the side chain may have an epoxy group. By using such a material, there is an effect that a film having excellent adhesion can be formed.
A specific example is as follows.

（式（３１）において、ｐ_７／ｑ_７＋ｒ_２は、２０以下である。）

(In formula (31), p ₇ / q ₇ + r ₂ is 20 or less.)

The compound represented by the formula (31) includes, for example, hexyl norbornene, diphenylmethyl norbornene methoxysilane (norbornene containing -CH ₂ -O-Si (CH ₃ ) (Ph) ₂ in the side chain) and epoxy norbornene in toluene. It can be obtained by dissolving and solution polymerization using a Ni compound as a catalyst.

((B) Monomer having a cyclic ether group, oligomer having a cyclic ether group)
Next, the component (B) will be described.

  Component (B) is at least one of a monomer having a cyclic ether group and an oligomer having a cyclic ether group. This component (B) may have any refractive index different from that of the resin of component (A) and is compatible with the resin of component (A). The refractive index difference between the component (B) and the resin of the component (A) is preferably 0.01 or more.

  The refractive index of the component (B) may be higher than that of the resin of the component (A), but the refractive index of the component (B) is preferably lower than that of the resin of the component (A).

  The monomer having a cyclic ether group and the oligomer having a cyclic ether group as component (B) are polymerized by ring-opening in the presence of an acid. Considering the diffusibility of the monomer and oligomer, the molecular weight (weight average molecular weight) of the monomer and the molecular weight (weight average molecular weight) of the oligomer are preferably 100 or more and 400 or less, respectively.

  Component (B) has, for example, an oxetanyl group or an epoxy group. Such a cyclic ether group is preferable because it is easily opened by an acid.

  As the monomer having an oxetanyl group and the oligomer having an oxetanyl group, those selected from the following formulas (11) to (20) are preferable. By using these, there is an advantage that transparency in the vicinity of a wavelength of 850 nm is excellent and both flexibility and heat resistance are possible. These may be used alone or in combination.

（式（１８）においてｎは０以上、３以下である。）

(In formula (18), n is 0 or more and 3 or less.)

  Among the above monomers and oligomers, they are represented by the formulas (13), (15), (16), (17), and (20) from the viewpoint of ensuring a difference in refractive index from the resin of the component (A). It is preferable to use a compound.

  Furthermore, considering the point that there is a difference in refractive index from the resin of component (A), the point that the molecular weight is small, the mobility of the monomer is high, and the point that the monomer does not easily volatilize, the formulas (20) and (15) It is particularly preferable to use a compound represented by:

  Moreover, as a compound which has an oxetanyl group, the compound represented by the following formula | equation (32) and a formula (33) can be used. As a compound represented by Formula (32), Toagosei Co., Ltd. trade name TESOX etc., and as a compound represented by Formula (33), Toagosei Co., Ltd. trade name OX-SQ etc. can be used.

（式（３３）において、ｎは１または２である）

(In formula (33), n is 1 or 2)

  Examples of the monomer having an epoxy group and the oligomer having an epoxy group include the following. The monomer and oligomer having an epoxy group are polymerized by ring-opening in the presence of an acid.

  As the monomer having an epoxy group and the oligomer having an epoxy group, those represented by the following formulas (34) to (39) can be used. Especially, it is preferable to use the alicyclic epoxy monomer represented by Formula (36)-(39) from a viewpoint that the distortion energy of an epoxy ring is large and is excellent in reactivity.

  In addition, the compound represented by Formula (34) is epoxy norbornene. As such a compound, for example, EpNB manufactured by Promerus Corporation can be used. The compound represented by the formula (35) is γ-glycidoxypropyltrimethoxysilane. As this compound, for example, Z-6040 manufactured by Toray Dow Corning Silicone can be used. The compound represented by the formula (36) is 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, and as this compound, for example, E0327 manufactured by Tokyo Chemical Industry can be used.

  Furthermore, the compound represented by the formula (37) is 3,4-epoxycyclohexenylmethyl-3, '4'-epoxycyclohexenecarboxylate. As this compound, for example, Celoxide 2021P manufactured by Daicel Chemical Industries, Ltd. is used. can do. Further, the compound represented by the formula (38) is 1,2-epoxy-4-vinylcyclohexane. As this compound, for example, Celoxide 2000 manufactured by Daicel Chemical Industries, Ltd. can be used.

  Furthermore, the compound represented by the formula (39) is 1,2: 8,9 diepoxy limonene. As this compound, for example, (Celoxide 3000 manufactured by Daicel Chemical Industries, Ltd.) can be used.

  Furthermore, as the component (B), a monomer having an oxetanyl group, an oligomer having an oxetanyl group, a monomer having an epoxy group, and an oligomer having an epoxy group may be used in combination.

  Monomers having an oxetanyl group and oligomers having an oxetanyl group have a slow initiation reaction but a fast growth reaction. On the other hand, a monomer having an epoxy group and an oligomer having an epoxy group have a fast initiation reaction for initiating polymerization but a slow growth reaction. Therefore, by using a monomer having an oxetanyl group, an oligomer having an oxetanyl group, a monomer having an epoxy group, and an oligomer having an epoxy group, when irradiated with light, the light irradiated portion and the unirradiated portion A difference in refractive index can be reliably generated.

  The addition amount of the component (B) is preferably 1 part by weight or more and 50 parts by weight or less, more preferably 2 parts by weight or more and 20 parts by weight or less with respect to 100 parts by weight of the component (A). . Thereby, the refractive index modulation between the core and the clad is possible, and there is an effect that both flexibility and heat resistance can be achieved.

((C) Photoacid generator)
Any photoacid generator may be used as long as it absorbs light energy to generate Bronsted acid or Lewis acid. For example, triphenylsulfonium trifluoromethanesulfonate, tris (4-t-butylphenyl) sulfonium- Sulfonium salts such as trifluoromethanesulfonate, diazonium salts such as p-nitrophenyldiazonium hexafluorophosphate, ammonium salts, phosphonium salts, diphenyliodonium trifluoromethanesulfonate, iodonium salts such as (triccumyl) iodonium-tetrakis (pentafluorophenyl) borate, Quinonediazides, diazomethanes such as bis (phenylsulfonyl) diazomethane, 1-phenyl-1- (4-methylphenyl) sulfonyl Sulfonic acid esters such as xyl-1-benzoylmethane and N-hydroxynaphthalimide-trifluoromethanesulfonate, disulfones such as diphenyldisulfone, tris (2,4,6-trichloromethyl) -s-triazine, 2- ( And compounds such as triazines such as 3.4-methylenedioxyphenyl) -4,6-bis- (trichloromethyl) -s-triazine. These photoacid generators can be used alone or in combination.

  The content of the photoacid generator is preferably 0.01 parts by weight or more and 0.3 parts by weight or less with respect to 100 parts by weight of the component (A), and is 0.02 parts by weight or more and 0.2 parts by weight or less. It is more preferable that Thereby, there exists an effect of a reactive improvement.

  The photosensitive resin composition may contain additives such as a sensitizer in addition to the above components (A), (B), and (C).

  The sensitizer increases the sensitivity of the photoacid generator to light and is suitable for reducing the time and energy required for activation (reaction or decomposition) of the photoacid generator and for activating the photoacid generator. It has a function of changing the wavelength of light to a wavelength.

  Such a sensitizer is appropriately selected according to the sensitivity of the photoacid generator and the peak wavelength of absorption of the sensitizer, and is not particularly limited. For example, 9,10-dibutoxyanthracene (CAS No. 76275) is selected. -14-4) anthracenes, xanthones, anthraquinones, phenanthrenes, chrysene, benzpyrenes, fluoranthenes, rubrenes, pyrenes, indanthrines, thioxanthen-9-one (Thioxanthen-9-ones) and the like, and these can be used alone or as a mixture.

  Specific examples of the sensitizer include, for example, 2-isopropyl-9H-thioxanthen-9-one, 4-isopropyl-9H-thioxanthen-9-one, 1-chloro-4-propoxythioxanthone, phenothiazine. Or a mixture thereof.

  The content of the sensitizer in the photosensitive resin composition is preferably 0.01% by weight or more, more preferably 0.5% by weight or more, and further preferably 1% by weight or more. preferable. In addition, it is preferable that an upper limit is 5 weight% or less.

  Among the above photosensitive resin compositions, the cyclic olefin resin having a leaving group in the side chain as the component (A), the photoacid generator of the component (C), and the following formula (100) as the component (B) The photosensitive resin composition containing the 1st monomer as described in above is especially preferable.

Hereinafter, this particularly preferable photosensitive resin composition will be described.
As the cyclic olefin resin (A) constituting the cyclic olefin resin having a leaving group in the side chain, those described above can be used. For example, polymers of monocyclic monomers such as cyclohexene and cyclooctene, Examples include polymers of polycyclic monomers such as norbornene, norbornadiene, dicyclopentadiene, dihydrodicyclopentadiene, tetracyclododecene, tricyclopentadiene, dihydrotricyclopentadiene, tetracyclopentadiene, and dihydrotetracyclopentadiene. Among these, one or more cyclic olefin resins selected from polymers of polycyclic monomers are preferably used. Thereby, the heat resistance of resin can be improved.

  In addition, as polymerization forms, known forms such as random polymerization and block polymerization can be applied. For example, specific examples of polymerization of norbornene type monomers include (co) polymers of norbornene type monomers, copolymers of norbornene type monomers and other monomers capable of copolymerization such as α-olefins, and the like. A hydrogenated product of the above copolymer corresponds to a specific example. These cyclic olefin resins can be produced by a known polymerization method. The polymerization methods include an addition polymerization method and a ring-opening polymerization method. Among the above, the cyclic olefin resin (particularly, the addition polymerization method) Norbornene resin) is preferable (that is, an addition polymer of a norbornene compound). Thereby, it is excellent in transparency, heat resistance, and flexibility.

As the leaving group, a part of the molecule is cleaved by the action of an acid (H ⁺ ) generated from a photoacid generator, and then leaves. Specifically, those having at least one of the aforementioned -O- structure, -Si-aryl structure and -O-Si- structure in the molecular structure (side chain) are preferable. The leaving group as described above is released relatively easily by the action of acid (H ⁺ ).

  Among the above-described leaving groups, the leaving group that causes a decrease in the refractive index of the resin by leaving is preferably at least one of a -Si-diphenyl structure and a -O-Si-diphenyl structure.

  The content of the leaving group is not particularly limited, but is preferably 10 to 80% by weight, particularly 20 to 60% by weight in the cyclic olefin resin having a leaving group in the side chain. Is more preferable. When the content is within the above range, it is particularly excellent in both flexibility and refractive index modulation function (effect of increasing the refractive index difference).

  As such a cyclic olefin resin having a leaving group in the side chain, one having a repeating unit represented by the following formula (101) and / or the following formula (102) is preferable. Thereby, the refractive index of resin can be made high.

（式１０１においてｎは０以上、９以下の整数である。）

(In Formula 101, n is an integer of 0 or more and 9 or less.)

  The photosensitive resin composition includes a monomer described in the above formula (100) (hereinafter referred to as a first monomer). Thereby, the refractive index difference between the left and right cores / claddings can be further expanded.

  The content of the first monomer is not particularly limited, but is preferably 1 part by weight or more and 50 parts by weight or less, particularly 2 parts by weight, based on 100 parts by weight of the cyclic olefin resin having a leaving group in the side chain. It is preferable that it is 20 parts by weight or more. Thereby, the refractive index modulation between the core / cladding is made possible, and both flexibility and heat resistance can be achieved.

  Thus, when the first monomer described above is used in combination with a cyclic olefin resin having a leaving group in the side chain, the reason for excellent balance between the refractive index modulation between the core and the clad and flexibility is as follows. It is considered as follows.

  First, when using the photosensitive resin composition as described above, it is excellent in the refractive index modulation between the core and the clad when the first monomer starts a polymerization reaction by an acid generated by light irradiation or the like. This is because the first monomer is excellent in the reactivity. When the reactivity of the first monomer is excellent, the curability of the first monomer is increased, and the diffusibility of the first monomer caused by the concentration gradient of the first monomer is improved. Thereby, the refractive index difference between the light irradiation region and the non-irradiation region can be increased.

  Further, since the first monomer is monofunctional, the polymerization reaction proceeds and the crosslinking density as the photosensitive resin composition does not become so high. Therefore, it is excellent in flexibility.

  Although the said photosensitive resin composition is not specifically limited, The 2nd monomer different from the said 1st monomer may be included. The second monomer different from the first monomer may be a monomer having a different structure or a monomer having a different molecular weight.

  Especially, the 2nd monomer is contained as a component (B), for example, an oxetane compound different from what is shown by an epoxy compound, Formula (100), a vinyl ether compound, etc. are mentioned. Among these, at least one of an epoxy compound (particularly an alicyclic epoxy compound) and a bifunctional oxetane compound (a monomer having two oxetanyl groups) is preferable. Thereby, the reactivity of the first monomer and the cyclic olefin resin can be improved, whereby the heat resistance of the waveguide can be improved while maintaining transparency.

  Specifically, the second monomer includes the compound of the above formula (15), the compound of the above formula (12), the compound of the above formula (11), the compound of the above formula (18), and the compound of the above formula (19). And compounds of the above formulas (34) to (39).

  The content of the second monomer is not particularly limited, but is preferably 1 part by weight or more and 50 parts by weight or less, particularly 2 parts by weight or more and 20 parts by weight or less with respect to 100 parts by weight of the cyclic olefin resin. More preferably. Thereby, the reactivity with the first monomer can be improved.

  Further, the combined ratio of the second monomer and the first monomer is not particularly limited, but is preferably 0.1 to 1 in weight ratio (weight of the second monomer / weight of the first monomer), particularly 0. .1 to 0.6 are preferred. When the combined ratio is within the above range, the balance between the speed of reactivity and the heat resistance of the waveguide is excellent.

  Although content of a photo-acid generator is not specifically limited, It is 0.01 weight part or more and 0.3 weight part or less with respect to 100 weight part of cyclic olefin resin which has a leaving group in the said side chain. In particular, it is more preferably 0.02 parts by weight or more and 0.2 parts by weight or less. If the content is less than the lower limit, the reactivity may decrease, and if the content exceeds the upper limit, the optical waveguide may be colored and light loss may decrease.

  The photosensitive resin composition may contain a curing catalyst, an antioxidant, and the like in addition to the above-mentioned cyclic olefin resin, photoacid generator, first monomer and second monomer.

  Further, the above-described photosensitive resin composition can be used as a composition for forming the core portion 94.

(Optical waveguide manufacturing method)
8, 9, and 10 are cross-sectional views schematically showing process examples of the method for manufacturing an optical waveguide.

  Here, a method for producing an optical waveguide using a photosensitive resin composition when the component (B) has a lower refractive index than the cyclic olefin resin of the component (A) will be described as an example.

  First, as shown in FIG. 8A, the varnish 900 is prepared by dissolving the photosensitive resin composition in a solvent, and this varnish 900 is applied onto the clad layer 91.

  Examples of the solvent for preparing the photosensitive resin composition in the form of varnish include diethyl ether, diisopropyl ether, 1,2-dimethoxyethane (DME), 1,4-dioxane, tetrahydrofuran (THF), tetrahydropyran (THP), Ether solvents such as anisole, diethylene glycol dimethyl ether (diglyme), diethylene glycol ethyl ether (carbitol), cellosolv solvents such as methyl cellosolve, ethyl cellosolve, phenyl cellosolve, aliphatic hydrocarbon solvents such as hexane, pentane, heptane, cyclohexane , Toluene, xylene, benzene, mesitylene and other aromatic hydrocarbon solvents, pyridine, pyrazine, furan, pyrrole, thiophene, methylpyrrolidone and other aromatic heterocyclic compounds Amide solvents such as N, N-dimethylformamide (DMF) and N, N-dimethylacetamide (DMA), halogen compound solvents such as dichloromethane, chloroform and 1,2-dichloroethane, ethyl acetate, methyl acetate, ethyl formate, etc. Ester solvents, various organic solvents such as sulfur compound solvents such as dimethyl sulfoxide (DMSO) and sulfolane, or mixed solvents containing them.

  Next, the varnish 900 is applied on the cladding layer 91 of the optical waveguide 9 and then dried to evaporate (desolve) the solvent. Accordingly, as shown in FIG. 8B, the varnish 900 becomes a film 910 for forming an optical waveguide. The film 910 becomes a core layer 93 in which a core portion 94 and a clad portion 95 are formed by light irradiation described later.

  Here, examples of the method of applying the varnish 900 include a doctor blade method, a spin coating method, a dipping method, a table coating method, a spray method, an applicator method, a curtain coating method, and a die coating method. It is not limited. As the clad layer 91, for example, a sheet having a refractive index lower than that of a core portion 94 described later is used, and for example, a sheet containing a norbornene-based resin and an epoxy resin is used.

Next, the film 910 is selectively irradiated with light (for example, ultraviolet rays).
At this time, as shown in FIG. 9A, a mask M in which an opening is formed is disposed above the film 910. The film 910 is irradiated with light through the opening of the mask M.

  As light used, what has a peak wavelength in the range of wavelength 200-450 nm is mentioned, for example. Thereby, although depending on the composition of the photoacid generator, the photoacid generator can be activated relatively easily.

The irradiation amount of light is not particularly limited, and is preferably about 0.1~9J / cm ^2, more preferably about 0.2~6J / cm ^2, 0.2~3J / More preferably, it is about cm ² .

  Note that the use of the mask M can be omitted when highly directional light such as laser light is used.

  In the region of the film 910 that is irradiated with light, an acid is generated from the photoacid generator. The component (B) is polymerized by the generated acid.

  In the region not irradiated with light, no acid is generated from the photoacid generator, so that component (B) is not polymerized. In the irradiated part, since the component (B) is polymerized to become a polymer, the amount of the component (B) is reduced. In response to this, the component (B) of the unirradiated part diffuses into the irradiated part, thereby causing a refractive index difference between the irradiated part and the unirradiated part.

  Here, when the component (B) has a lower refractive index than the cyclic olefin resin, the component (B) of the unirradiated part diffuses into the irradiated part, and the refractive index of the unirradiated part increases. The refractive index of the irradiated part is lowered.

  In addition, the refractive index difference between the polymer obtained by polymerizing the component (B) and the monomer having a cyclic ether group is about 0 or more and 0.001 or less, and the refractive indexes are considered to be substantially the same.

  Thus, when the photosensitive resin composition mentioned above is used, it is possible to start superposition | polymerization of a component (B) with the acid generate | occur | produced from a photo-acid generator.

  Furthermore, the cyclic olefin resin used in the present invention does not necessarily have a leaving group, but when a cyclic olefin resin having a leaving group is used as the component (A), The following effects occur.

  In the portion irradiated with light, the leaving group of the cyclic olefin resin is eliminated by the acid generated from the photoacid generator. In the case of a leaving group such as a -Si-aryl structure, a -Si-diphenyl structure, and a -O-Si-diphenyl structure, the refractive index of the resin decreases due to the leaving. Therefore, the refractive index of the irradiated portion is further lowered as compared with that before the leaving group is removed.

  Next, the film 910 is heated. In this heating step, the component (B) of the irradiated portion irradiated with light is further polymerized. On the other hand, in this heating step, the component (B) in the unirradiated part is volatilized. Thereby, in an unirradiated part, a component (B) decreases and it becomes a refractive index close | similar to cyclic olefin resin.

  In this film 910, as shown in FIG. 9B, the region irradiated with light becomes the cladding portion 95, and the non-irradiated region becomes the core portion 94. The structure concentration derived from the component (B) in the core portion 94 and the structure concentration derived from the component (B) in the cladding portion 95 are different. Specifically, the structure concentration derived from the component (B) in the core portion 94 is lower than the structure concentration derived from the component (B) in the cladding portion 95.

  The clad part 95 has a lower refractive index than the core part 94, and the refractive index difference between the clad part 95 and the core part 94 is 0.01 or more. As described above, the core portion 94 and the clad portion 95 are formed on the film 910, and the core layer 93 is obtained.

  The heating temperature in this heating step is not particularly limited, but is preferably about 30 to 180 ° C, and more preferably about 40 to 160 ° C.

  In addition, the heating time is preferably set so that the polymerization reaction of the component (B) of the irradiated part irradiated with light is almost completed, specifically, preferably about 0.1 to 2 hours, More preferably, it is about 0.1 to 1 hour.

  Thereafter, a film similar to the clad layer 91 is attached on the core layer 93. This film becomes the clad layer 92. The pair of clad layers 91 and 92 are arranged so as to sandwich the core portion 94 from a direction different from the clad portion 95.

The clad layer 92 can also be formed by a method of applying a liquid material on the core layer 93 and curing (solidifying) instead of attaching a film-like one.
Through the above steps, the optical waveguide 9 shown in FIG. 10 is obtained.

  Further, when the optical waveguide 9 is obtained from the photosensitive resin composition used in the present invention, the solder reflow resistance is particularly excellent. Furthermore, even when the optical waveguide 9 is bent, the optical loss can be reduced.

  In the above description, the case where the photosensitive resin composition is directly supplied onto the clad layer 91 to form the film 910 (core layer 93) has been described, but the film 910 (core layer) is formed on another substrate. 93), the obtained core layer 93 may be transferred onto the clad layer 91 or the clad layer 92, and then the clad layer 91 and the clad layer 92 may be overlapped via the core layer 93. .

Next, the effect of this embodiment is demonstrated.
When light is applied to the photosensitive resin composition used in the present embodiment, an acid is generated from the photoacid generator, and the component (B) is polymerized only in the irradiated portion. Then, since the amount of the component (B) in the irradiated part is reduced, the component (B) in the non-irradiated part diffuses into the irradiated part, thereby causing a difference in refractive index between the irradiated part and the unirradiated part. Specifically, in this embodiment, since a substituted or unsubstituted cyclic olefin resin having a higher refractive index than that of the component (B) is used as the base polymer, the component (B) in the unirradiated portion is irradiated with the irradiated portion. The refractive index of the unirradiated part becomes higher than the refractive index of the irradiated part.

  In addition to this, when the photosensitive resin composition is heated after light irradiation, the component (B) volatilizes from the unirradiated portion. Thereby, a refractive index difference further occurs between the irradiated portion and the unirradiated portion.

  Thus, by using the photosensitive resin composition, a refractive index difference can be reliably formed between the irradiated portion and the unirradiated portion. Further, according to the present invention, the core portion can be patterned by a simple method of simply irradiating light. For example, by appropriately selecting an exposure pattern such as a photomask, an optical path (core part) of any shape and arrangement can be formed, and a thin optical path can be formed sharply. This contributes to integration, and the device can be miniaturized. That is, according to the present invention, a core portion having a wide degree of freedom in designing the pattern shape of the core portion and high dimensional accuracy can be obtained.

  Conventionally, a technique for crosslinking a norbornene-based resin having an oxetanyl group or the like with a thermal acid generator is known. However, the composition used in such a technique contains a norbornene-based resin having an oxetanyl group or the like as a base polymer. And the whole composition is heated and a crosslinked structure is produced in the whole composition. Therefore, this composition that has been conventionally used is selectively irradiated with light to generate acid, thereby selectively causing polymerization, and the monomer diffuses into the region where the monomer concentration is reduced, There is no technical idea that density differences can be made.

  In contrast, when the photosensitive resin composition used in the present embodiment is selectively irradiated with light, the amount of the component (B) in the irradiated portion is reduced due to the generation of acid, so the component (B) in the unirradiated portion Has been found to diffuse into the irradiated portion, which causes a difference in refractive index between the irradiated portion and the unirradiated portion.

  Further, when the cyclic olefin resin has a leaving group that is desorbed by an acid generated from the photoacid generator and reduces the refractive index of the cyclic olefin resin of the component (A) by desorption, The refractive index of the region irradiated with light can be reliably reduced as compared with the unirradiated region.

  On the other hand, when the cyclic olefin resin has no leaving group, the side chain is chemically stable, so the refractive index of the core part and the clad part depends on conditions such as light irradiation and heating. Can be prevented from fluctuating.

  Furthermore, in this embodiment, norbornene-type resin is used as a component (A). Thereby, the light transmittance in a specific wavelength can be improved reliably, and reduction of propagation loss can be aimed at reliably.

  Further, the clad part 95 has a lower refractive index than the core part 94, and the difference in refractive index between the clad part 95 and the core part 94 is 0.01 or more, so that light can be reliably confined in the core part 94. And the generation of light propagation loss can be suppressed.

  On the other hand, conventionally, as a composition for forming an optical waveguide, a composition containing a polymer, a monomer, a promoter and a catalyst precursor is known.

  Among these, the monomer can form a reaction product by irradiation of light, and can make the refractive index of the region irradiated with light different from the refractive index of the unirradiated region.

  The catalyst precursor is a substance capable of initiating a monomer reaction (polymerization reaction, crosslinking reaction, etc.), and is a substance whose activation temperature is changed by the action of a promoter activated by light irradiation. Due to the change in the activation temperature, the temperature at which the monomer reaction starts is different between the light irradiation region and the non-irradiation region, and as a result, a reactant can be formed only in the irradiation region.

  Even when such a conventional composition is used, the core part and the clad part can be separately formed by light irradiation. However, according to the photosensitive resin composition used in the present embodiment, the core part 94 and the clad part. Since the difference in refractive index from 95 is further increased and the heat resistance is improved, the optical waveguide 9 having higher reliability can be obtained. This is because the compositions of the component (A) and the component (B) are optimized.

  It should be noted that the present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.

  Moreover, in the said embodiment, although the photosensitive resin composition was used and the optical waveguide film was formed, you may use for a hologram etc. not only in this. The above-mentioned photosensitive resin composition is suitable for forming a film in which a region having a high refractive index and a region having a low refractive index are mixed.

Next, examples of the present invention will be described.
A. Production of optical waveguide (Example 1)
(1) Synthesis of norbornene-based resin having a leaving group In a glove box filled with dry nitrogen in which the water and oxygen concentrations are both controlled to 1 ppm or less, 7.2 g (40.1 mmol) of hexylnorbornene (HxNB) ), 12.9 g (40.1 mmol) of diphenylmethylnorbornenemethoxysilane was weighed into a 500 mL vial, 60 g of dehydrated toluene and 11 g of ethyl acetate were added, and the top was sealed with a silicon sealer.

  Next, 1.56 g (3.2 mmol) of Ni catalyst represented by the following chemical formula (B) and 10 mL of dehydrated toluene are weighed in a 100 mL vial, put a stirrer chip and sealed, and the catalyst is thoroughly stirred to completely Dissolved in.

  When 1 mL of the Ni catalyst solution represented by the following chemical formula (B) is accurately weighed with a syringe, and quantitatively injected into the vial bottle in which the above two types of norbornene are dissolved, and stirred at room temperature for 1 hour, a marked increase in viscosity occurs. Was confirmed. At this point, the stopper was removed, 60 g of tetrahydrofuran (THF) was added, and the mixture was stirred to obtain a reaction solution.

  In a 100 mL beaker, 9.5 g of acetic anhydride, 18 g of hydrogen peroxide (concentration 30%) and 30 g of ion-exchanged water were added and stirred to prepare an aqueous solution of peracetic acid on the spot. Next, the total amount of this aqueous solution was added to the above reaction solution and stirred for 12 hours to reduce Ni.

  Next, the treated reaction solution was transferred to a separatory funnel, the lower aqueous layer was removed, and then 100 mL of a 30% aqueous solution of isopropyl alcohol was added and vigorously stirred. The aqueous layer was removed after standing and completely separating the two layers. After repeating this water washing process three times in total, the oil layer was dropped into a large excess of acetone to reprecipitate the polymer produced, separated from the filtrate by filtration, and then in a vacuum dryer set at 60 ° C. Polymer # 1 was obtained by heating and drying for 12 hours. The molecular weight distribution of the polymer # 1 was Mw = 100,000 and Mn = 40,000 by GPC measurement. Moreover, the molar ratio of each structural unit in the polymer # 1 was 50 mol% for the hexylbornene structural unit and 50 mol% for the diphenylmethylnorbornenemethoxysilane structural unit, as determined by NMR. The refractive index was 1.55 (measurement wavelength: 633 nm) by Metricon.

(2) Production of photosensitive resin composition 10 g of the purified polymer # 1 was weighed into a 100 mL glass container, and 40 g of mesitylene, 0.01 g of antioxidant Irganox 1076 (manufactured by Ciba Geigy), cyclohexyl oxetane monomer (formula 20) First monomer represented by (Formula 100), Toa Gosei CHOX, CAS # 483303-25-9, molecular weight 186, boiling point 125 ° C./1.33 kPa) 2 g, photoacid generator Rhodorsil Photoinitiator 2074 (manufactured by Rhodia, CAS #) 178233-72-2) (1.36E-2 g in 0.1 mL of ethyl acetate) and uniformly dissolved, and then filtered through a 0.2 μm PTFE filter to obtain a clean photosensitive resin composition varnish V1. It was.

(3) Production of optical waveguide film (production of lower clad layer)
A photosensitive norbornene resin composition (Avatrel 2000P varnish manufactured by Promeras Co., Ltd.) was uniformly applied on a silicon wafer with a doctor blade, and then placed in a dryer at 45 ° C. for 15 minutes. After completely removing the solvent, the entire coated surface was irradiated with 100 mJ of ultraviolet light and heated in a dryer at 120 ° C. for 1 hour to cure the coating film to form a lower clad layer. The formed lower cladding layer had a thickness of 20 μm, was colorless and transparent, and had a refractive index of 1.52 (measurement wavelength: 633 nm).

(Formation of core layer)
After the photosensitive resin composition varnish V1 was uniformly applied on the lower clad layer with a doctor blade, it was put into a dryer at 45 ° C. for 15 minutes. After completely removing the solvent, a photomask was pressed and selectively irradiated with ultraviolet rays at 500 mJ / cm ² . The mask was removed, and heating was performed in three stages in a dryer at 45 ° C. for 30 minutes, 85 ° C. for 30 minutes, and 150 ° C. for 1 hour. It was confirmed that a very clear waveguide pattern appeared after heating. Moreover, formation of the core part and the clad part was confirmed.

(Formation of upper cladding layer)
A dry film in which Avatrel 2000P is laminated in advance on a polyethersulfone (PES) film so as to have a dry thickness of 20 μm is bonded to the above core layer, and put into a vacuum laminator set at 140 ° C. for thermocompression bonding. It was. Thereafter, 100 mJ was irradiated on the entire surface and heated in a dryer at 120 ° C. for 1 hour to cure Avatrel 2000P to form an upper clad layer to obtain an optical waveguide. At this time, the upper cladding layer was colorless and transparent, and its refractive index was 1.52.

(4) Evaluation (Evaluation of optical waveguide loss)
Light emitted from an 850 nm VCSEL (surface emitting laser) was introduced into the optical waveguide via a 50 μmφ optical fiber, received by a 200 μmφ optical fiber, and the light intensity was measured. The cutback method was used for the measurement. When the longitudinal direction of the optical waveguide is taken on the horizontal axis and the insertion loss is plotted on the vertical axis, the measured values are neatly arranged on a straight line, and the propagation loss can be calculated as 0.03 dB / cm from the inclination. .

(Refractive index difference between core and clad)
The refractive index difference between the left and right core portions and the clad portion adjacent in the horizontal direction formed in the above (formation of the core layer) was determined as follows.

  Optical waveguide analyzer OWA-9500 manufactured by EXFO, Canada was used to irradiate the optical waveguide with laser light having a wavelength of 656 nm, and the refractive indexes of the core region and the cladding region were measured, and the difference between them was calculated. As a result, the refractive index difference was 0.02.

(Example 2)
(1) Synthesis of norbornene-based resin having no leaving group In a glove box filled with dry nitrogen in which the water and oxygen concentrations are both controlled to 1 ppm or less, 9.4 g of hexylnorbornene (HxNB) (53. 1 mmol) and 10.5 g (53.1 mmol) of phenylethylnorbornene were weighed into a 500 mL vial, 60 g of dehydrated toluene and 11 g of ethyl acetate were added, and the top was sealed with a silicon sealer.

  Next, weigh 2.06 g (3.2 mmol) of Ni catalyst represented by the above chemical formula (B) and 10 mL of dehydrated toluene in a 100 mL vial, put a stirrer chip and seal tightly, and thoroughly stir the catalyst. Dissolved in.

  When 1 mL of the Ni catalyst solution represented by the chemical formula (B) is accurately weighed with a syringe, and quantitatively injected into the vial bottle in which the two types of norbornene are dissolved and stirred at room temperature for 1 hour, a marked increase in viscosity is observed. confirmed. At this point, the stopper was removed, 60 g of tetrahydrofuran (THF) was added, and the mixture was stirred to obtain a reaction solution.

  In a 100 mL beaker, 9.5 g of acetic anhydride, 18 g of hydrogen peroxide (concentration 30%) and 30 g of ion-exchanged water were added and stirred to prepare an aqueous solution of peracetic acid on the spot. Next, the total amount of this aqueous solution was added to the above reaction solution and stirred for 12 hours to reduce Ni.

  Next, the treated reaction solution was transferred to a separatory funnel, the lower aqueous layer was removed, and then 100 mL of a 30% aqueous solution of isopropyl alcohol was added and vigorously stirred. The aqueous layer was removed after standing and completely separating the two layers. After repeating this water washing process three times in total, the oil layer was dropped into a large excess of acetone to reprecipitate the polymer produced, separated from the filtrate by filtration, and then in a vacuum dryer set at 60 ° C. Polymer # 2 was obtained by heat drying for 12 hours. The molecular weight distribution of the polymer # 2 was Mw = 90,000 and Mn = 40,000 by GPC measurement. The molar ratio of each structural unit in polymer # 2 was 50 mol% for the hexylbornene structural unit and 50 mol% for the phenylethylnorbornene structural unit, as determined by NMR. The refractive index was 1.54 (measurement wavelength: 633 nm) by Metricon.

(2) Production of photosensitive resin composition 10 g of the purified polymer # 2 was weighed into a 100 mL glass container, and 40 g of mesitylene, 0.01 g of an antioxidant Irganox 1076 (manufactured by Ciba Geigy), cyclohexyloxetane monomer (formula 20) 2 g, photoacid generator Rhodorsil Photoinitiator 2074 (manufactured by Rhodia, CAS # 178233-72-2), manufactured by Toa Gosei Co., Ltd. CHOX, CAS # 48333-3-25-9, molecular weight 186, boiling point 125 ° C./1.33 kPa) (1.36E-2 g, in 0.1 mL of ethyl acetate) was added and dissolved uniformly, and then filtered through a 0.2 μm PTFE filter to obtain a clean photosensitive resin composition varnish V2.

(3) Production of optical waveguide film (production of lower clad layer)
A lower clad layer similar to that in Example 1 was produced.

(Formation of core layer)
After the photosensitive resin composition varnish V2 was uniformly applied on the lower clad layer with a doctor blade, it was put into a dryer at 45 ° C. for 15 minutes. After completely removing the solvent, a photomask was pressed and selectively irradiated with ultraviolet rays at 500 mJ / cm ² . The mask was removed, and heating was performed in three stages in a dryer at 45 ° C. for 30 minutes, 85 ° C. for 30 minutes, and 150 ° C. for 1 hour. It was confirmed that a very clear waveguide pattern appeared after heating. Moreover, formation of the core part and the clad part was confirmed.

(Formation of upper cladding layer)
An upper clad layer similar to that in Example 1 was produced.

(4) Evaluation Evaluation was performed in the same manner as in Example 1. The propagation loss could be calculated as 0.04 dB / cm. The difference in refractive index between the core portion and the cladding portion was 0.01.

(Example 3)
(1) Synthesis of norbornene-based resin having a leaving group A norbornene-based resin was produced in the same manner as in Example 1.

(2) Production of photosensitive resin composition 10 g of the purified polymer # 1 was weighed into a 100 mL glass container, and 40 g of mesitylene, an antioxidant Irganox 1076 (manufactured by Ciba Geigy) 0.01 g, a bifunctional oxetane monomer (formula (15), manufactured by Toa Gosei Co., Ltd., DOX, CAS # 18934-00-4, molecular weight 214, boiling point 119 ° C./0.67 kPa) 2 g, photoacid generator Rhodosil Photoinitiator 2074 (manufactured by Rhodia Co., CAS # 178233-) 72-2) (1.36E-2 g in 0.1 mL of ethyl acetate) was added and dissolved uniformly, and then filtered through a 0.2 μm PTFE filter to obtain a clean photosensitive resin composition varnish V3.

(3) Production of optical waveguide film (production of lower clad layer)
A lower clad layer similar to that in Example 1 was produced.

(Formation of core layer)
After the photosensitive resin composition varnish V3 was uniformly applied on the lower clad layer with a doctor blade, it was put into a dryer at 45 ° C. for 15 minutes. After completely removing the solvent, a photomask was pressed and selectively irradiated with ultraviolet rays at 500 mJ / cm ² . The mask was removed, and heating was performed in three stages in a dryer at 45 ° C. for 30 minutes, 85 ° C. for 30 minutes, and 150 ° C. for 1 hour. It was confirmed that a very clear waveguide pattern appeared after heating. Moreover, formation of the core part and the clad part was confirmed.
(Formation of upper cladding layer)
An upper clad layer similar to that in Example 1 was produced.

(4) Evaluation Evaluation was performed in the same manner as in Example 1. The propagation loss could be calculated as 0.04 dB / cm. The difference in refractive index between the core portion and the cladding portion was 0.01.

Example 4
(1) Synthesis of norbornene-based resin having a leaving group A norbornene-based resin was produced in the same manner as in Example 1.

(2) Production of photosensitive resin composition 10 g of the purified polymer # 1 was weighed into a 100 mL glass container, and 40 g of mesitylene, 0.01 g of an antioxidant Irganox 1076 (manufactured by Ciba Geigy), an alicyclic epoxy monomer ( Formula (37), manufactured by Daicel Chemical Industries, Celoxide 2021P, CAS # 2386-87-0, molecular weight 252, boiling point 188 ° C./4 hPa) 2 g, photoacid generator Rhodorsil Photoinitiator 2074 (manufactured by Rhodia, CAS # 178233-) 72-2) (1.36E-2 g in 0.1 mL of ethyl acetate) was added and dissolved uniformly, and then filtered through a 0.2 μm PTFE filter to obtain a clean photosensitive resin composition varnish V4.

(3) Production of optical waveguide film (production of lower clad layer)
A lower clad layer similar to that in Example 1 was produced.

(Formation of core layer)
After the photosensitive resin composition varnish V4 was uniformly applied on the lower clad layer with a doctor blade, it was put into a dryer at 45 ° C. for 15 minutes. After completely removing the solvent, a photomask was pressed and selectively irradiated with ultraviolet rays at 500 mJ / cm ² . The mask was removed, and heating was performed in three stages in a dryer at 45 ° C. for 30 minutes, 85 ° C. for 30 minutes, and 150 ° C. for 1 hour. It was confirmed that a very clear waveguide pattern appeared after heating. Moreover, formation of the core part and the clad part was confirmed.

(Formation of upper cladding layer)
An upper clad layer similar to that in Example 1 was produced.

(4) Evaluation Evaluation was performed in the same manner as in Example 1. The propagation loss could be calculated as 0.04 dB / cm. The difference in refractive index between the core portion and the cladding portion was 0.01.

(Example 5)
(1) Synthesis of norbornene-based resin having a leaving group A norbornene-based resin was produced in the same manner as in Example 1.

(2) Production of photosensitive resin composition 10 g of the purified polymer # 1 was weighed into a 100 mL glass container, and 40 g of mesitylene, 0.01 g of antioxidant Irganox 1076 (manufactured by Ciba Geigy), cyclohexyl oxetane monomer (formula 20) 1 g of CHOX manufactured by Toagosei Co., Ltd. 1 g of alicyclic epoxy monomer (manufactured by Daicel Chemical Industries, Celoxide 2021P), photoacid generator Rhodosil Photoinitiator 2074 (manufactured by Rhodia, CAS # 178233-72-2) (1.36E- 2 g in 0.1 mL of ethyl acetate) and uniformly dissolved, and then filtered through a 0.2 μm PTFE filter to obtain a clean photosensitive resin composition varnish V5.

(3) Production of optical waveguide film (production of lower clad layer)
A lower clad layer similar to that in Example 1 was produced.

(Formation of core layer)
After the photosensitive resin composition varnish V5 was uniformly applied on the lower clad layer with a doctor blade, it was put into a dryer at 45 ° C. for 15 minutes. After completely removing the solvent, a photomask was pressed and selectively irradiated with ultraviolet rays at 500 mJ / cm ² . The mask was removed, and heating was performed in three stages in a dryer at 45 ° C. for 30 minutes, 85 ° C. for 30 minutes, and 150 ° C. for 1 hour. It was confirmed that a very clear waveguide pattern appeared after heating. Moreover, formation of the core part and the clad part was confirmed.

(Formation of upper cladding layer)
An upper clad layer similar to that in Example 1 was produced.

(4) Evaluation Evaluation was performed in the same manner as in Example 1. The propagation loss could be calculated as 0.03 dB / cm. The difference in refractive index between the core portion and the cladding portion was 0.01.

(Example 6)
(1) Synthesis of norbornene-based resin having a leaving group A norbornene-based resin was produced in the same manner as in Example 1.

(2) Production of photosensitive resin composition 10 g of the purified polymer # 1 was weighed into a 100 mL glass container, and 40 g of mesitylene, 0.01 g of antioxidant Irganox 1076 (manufactured by Ciba Geigy), cyclohexyl oxetane monomer (formula 20) And 1.5 g of a photoacid generator, Rhodosil Photoinitiator 2074 (manufactured by Rhodia, CAS # 178233-72-2) (1.36E-2 g in 0.1 mL of ethyl acetate) and uniformly added. After dissolution, filtration was performed with a 0.2 μm PTFE filter to obtain a clean photosensitive resin composition varnish V6.

(3) Production of optical waveguide film (production of lower clad layer)
A lower clad layer similar to that in Example 1 was produced.

(Formation of core layer)
After the photosensitive resin composition varnish V6 was uniformly applied on the lower clad layer with a doctor blade, it was put into a dryer at 45 ° C. for 15 minutes. After completely removing the solvent, a photomask was pressed and selectively irradiated with ultraviolet rays at 500 mJ / cm ² . The mask was removed, and heating was performed in three stages in a dryer at 45 ° C. for 30 minutes, 85 ° C. for 30 minutes, and 150 ° C. for 1 hour. It was confirmed that a very clear waveguide pattern appeared after heating. Moreover, formation of the core part and the clad part was confirmed.

(Formation of upper cladding layer)
An upper clad layer similar to that in Example 1 was produced.

(4) Evaluation Evaluation was performed in the same manner as in Example 1. The propagation loss could be calculated as 0.03 dB / cm. The difference in refractive index between the core portion and the cladding portion was 0.01.

(Example 7)
(1) Synthesis of norbornene-based resin having a leaving group In a glove box whose water and oxygen concentrations are both controlled to 1 ppm or less and filled with dry nitrogen, 6.4 g (36.1 mmol) of hexylnorbornene (HxNB) ), Diphenylmethylnorbornene methoxysilane (diPhNB) 8.7 g (27.1 mmol), epoxy norbornene (EpNB) 4.9 g (27.1 mmol) were weighed into a 500 mL vial, 60 g of dehydrated toluene and 11 g of ethyl acetate were added, The top was sealed with a silicon sealer.

  Next, 1.75 g (3.2 mmol) of the Ni catalyst represented by the above chemical formula (B) and 10 mL of dehydrated toluene are weighed in a 100 mL vial, put a stirrer chip and sealed, and the catalyst is thoroughly stirred to completely Dissolved in.

  When 1 mL of the Ni catalyst solution represented by the above chemical formula (B) is accurately weighed with a syringe, and quantitatively injected into the vial bottle in which the three types of norbornene are dissolved, and stirred at room temperature for 1 hour, a marked increase in viscosity occurs. Was confirmed. At this point, the stopper was removed, 60 g of tetrahydrofuran (THF) was added, and the mixture was stirred to obtain a reaction solution.

  In a 100 mL beaker, 9.5 g of acetic anhydride, 18 g of hydrogen peroxide (concentration 30%) and 30 g of ion-exchanged water were added and stirred to prepare an aqueous solution of peracetic acid on the spot. Next, the total amount of this aqueous solution was added to the above reaction solution and stirred for 12 hours to reduce Ni.

  Next, the treated reaction solution was transferred to a separatory funnel, the lower aqueous layer was removed, and then 100 mL of a 30% aqueous solution of isopropyl alcohol isopropyl alcohol was added and vigorously stirred. The aqueous layer was removed after standing and completely separating the two layers. After repeating this water washing process three times in total, the oil layer was dropped into a large excess of acetone to reprecipitate the polymer produced, separated from the filtrate by filtration, and then in a vacuum dryer set at 60 ° C. Polymer # 3 was obtained by heat drying for 12 hours. The molecular weight distribution of the polymer # 3 was Mw = 80,000 and Mn = 40,000 by GPC measurement. The molar ratio of each structural unit in polymer # 3 was 40 mol% for hexylbornene structural unit, 30 mol% for diphenylmethylnorbornenemethoxysilane structural unit, and 30 mol% for epoxynorbornene structural unit, as determined by NMR. It was. The refractive index was 1.53 (measurement wavelength: 633 nm) by Metricon.

(2) Production of photosensitive resin composition 10 g of the purified polymer # 3 was weighed into a 100 mL glass container, and 40 g of mesitylene, 0.01 g of antioxidant Irganox 1076 (manufactured by Ciba Geigy), cyclohexyloxetane monomer (formula 20) 1), CHOX manufactured by Toa Gosei Co., Ltd., and photoacid generator Rhodosil Photoinitiator 2074 (manufactured by Rhodia, CAS # 178233-72-2) (1.36E-2 g, in 0.1 mL of ethyl acetate) are uniformly added. After dissolution, filtration was performed with a 0.2 μm PTFE filter to obtain a clean photosensitive resin composition varnish V7.

(3) Production of optical waveguide film (production of lower clad layer)
A lower clad layer similar to that in Example 1 was produced.

(Formation of core layer)
After the photosensitive resin composition varnish V7 was uniformly applied on the lower clad layer with a doctor blade, it was put into a dryer at 45 ° C. for 15 minutes. After completely removing the solvent, a photomask was pressed and selectively irradiated with ultraviolet rays at 500 mJ / cm ² . The mask was removed, and heating was performed in three stages in a dryer at 45 ° C. for 30 minutes, 85 ° C. for 30 minutes, and 150 ° C. for 1 hour. It was confirmed that a very clear waveguide pattern appeared after heating. Moreover, formation of the core part and the clad part was confirmed.

(Formation of upper cladding layer)
An upper clad similar to that of Example 1 was produced.

(4) Evaluation Evaluation was performed in the same manner as in Example 1. The propagation loss could be calculated as 0.04 dB / cm. The refractive index difference between the core portion and the clad portion was 0.02.
The evaluation results of the optical waveguide films obtained in Examples 1 to 7 are shown in Table 1 above.

In Examples 1 to 7, when light is applied to the photosensitive resin composition, an acid is generated from the photoacid generator, and a monomer having a cyclic ether group is polymerized only in the irradiated portion. Then, since the amount of unreacted monomer in the irradiated part decreases, the monomer in the unirradiated part diffuses into the irradiated part in order to eliminate the concentration gradient generated between the irradiated part / unirradiated part.
Further, when heating is performed after light irradiation, the monomer volatilizes from the unirradiated portion.

  As described above, the structure concentration derived from the monomer is different between the core portion and the cladding portion, the structure derived from the monomer having a cyclic ether group increases in the cladding portion, and the monomer derived from the monomer having a cyclic ether group is present in the core portion. There are fewer structures. This is recognized from the fact that a relatively large refractive index difference of 0.01 or more occurs between the core portion and the cladding portion.

  In Examples 1 to 7, a linear optical waveguide is formed. However, when a curved optical waveguide (with a radius of curvature of about 10 mm) is formed, it is remarkable that optical loss is small.

  Furthermore, the optical waveguide films obtained in Examples 1 to 7 have high heat resistance and have reflow resistance of 260 ° C.

(Example 8)
(1) Synthesis of norbornene resin having a leaving group In the synthesis of a norbornene resin having a leaving group, phenyldimethylnorbornenemethoxysilane was used instead of 12.9 g (40.1 mmol) of diphenylmethylnorbornenemethoxysilane. Example 1 was repeated except that 4 g (40.1 mmol) was used. The molecular weight of the obtained norbornene resin B (Formula 103) having a leaving group in the side chain was Mw = 110,000 and Mn = 50,000 by GPC measurement. The molar ratio of each structural unit was 50 mol% for the hexylnorbornene structural unit and 50 mol% for the phenyldimethylnorbornenemethoxysilane structural unit, as determined by NMR. The refractive index was 1.53 (measurement wavelength: 633 nm) by Metricon.

(2) Production of photosensitive resin composition A photosensitive resin composition was obtained in the same manner as in Example 1 except that the norbornene resin B was used instead of the polymer # 1.

(3) Production of optical waveguide film An optical waveguide film was obtained in the same manner as in Example 1 except that the photosensitive resin composition containing the norbornene-based resin B was used.

  When the loss evaluation of the optical waveguide was performed in the same manner as in Example 1, the propagation loss of the obtained optical waveguide film was 0.03 dB / cm.

Example 9
(1) The procedure was the same as Example 1 except that the following photosensitive resin composition was used.

  10 g of norbornene-based resin obtained in Example 1 was weighed into a 100 mL glass container, and 40 g of mesitylene, 0.01 g of an antioxidant Irganox 1076 (manufactured by Ciba Geigy), and a cyclohexyloxetane monomer (formula (100) represented by formula (100)). 1 monomer, manufactured by Toa Gosei CHOX, CAS # 483303-25-9, molecular weight 186, boiling point 125 ° C./1.33 kPa) 1 g, bifunctional oxetane monomer (second monomer represented by formula (104), manufactured by Toa Gosei, DOX , CAS # 18934-00-4, molecular weight 214, boiling point 119 ° C./0.67 kPa) 1 g, photoacid generator Rhodosil Photoinitiator 2074 (manufactured by Rhodia, CAS # 178233-72-2) (1.36E-2 g, ethyl acetate In 0.1 mL) After dissolving one was filtered through 0.2 [mu] m PTFE filter to prepare a photosensitive resin composition varnish for clean core layer.

(2) Production of optical waveguide film An optical waveguide film was obtained in the same manner as in Example 1 except that the photosensitive resin composition of (1) above was used.

  When the loss evaluation of the optical waveguide was performed in the same manner as in Example 1, the propagation loss of the obtained optical waveguide film was 0.04 dB / cm.

(Example 10)
Example 1 was repeated except that the following were used as the cyclic olefin.

(1) Synthesis of norbornene-based resin C Norbornene represented by the following formula (105) is obtained by performing ring-opening metathesis polymerization of phenylethylnorbornene (PENB) monomer using a known method (for example, JP-A-2003-252963). System resin C was obtained.

(2) Production of photosensitive resin composition A photosensitive resin composition was obtained in the same manner as in Example 1 except that the norbornene resin C was used instead of the polymer # 1.

(3) Production of optical waveguide film An optical waveguide film was obtained in the same manner as in Example 1 except that the photosensitive resin composition containing the norbornene-based resin C was used.

  When the loss evaluation of the optical waveguide was performed in the same manner as in Example 1, the propagation loss of the obtained optical waveguide film was 0.05 dB / cm.

(Example 11)
An optical waveguide film was produced in the same manner as in Example 1 except that the amount of the first monomer was changed to 0.5 g.
The propagation loss of the obtained optical waveguide film was 0.10 dB / cm.

(Example 12)
An optical waveguide film was produced in the same manner as in Example 1 except that the blending amount of the first monomer was 4.0 g.
The propagation loss of the obtained optical waveguide film was 0.10 dB / cm.

(Comparative Example 1)
An optical waveguide film was produced in the same manner as in Example 1 except that the first monomer was not used.
The propagation loss of the obtained optical waveguide film was 0.90 dB / cm.

(Comparative Example 2)
(1) Synthesis of each component <Catalyst precursor: Synthesis of Pd (OAc) ₂ (P (Cy) ₃ ) ₂ >
In a 2-neck round bottom flask equipped with a funnel, a reddish brown suspension consisting of Pd (OAc) ₂ (5.00 g, 22.3 mmol) and CH ₂ Cl ₂ (30 mL) was stirred at −78 ° C.

A funnel was charged with a CH ₂ Cl ₂ solution (30 mL) of P (Cy) ₃ (13.12 mL (44.6 mmol)) and added dropwise to the stirred suspension over 15 minutes. As a result, the color gradually changed from reddish brown to yellow.

  After stirring at −78 ° C. for 1 hour, the suspension was warmed to room temperature, stirred for an additional 2 hours, and diluted with hexane (20 mL).

  The yellow solid was then filtered in air, washed with pentane (5 × 10 mL) and dried in vacuo.

  The secondary collection was separated by cooling the filtrate to 0 ° C., washed and dried as above. As a result, a catalyst precursor was obtained.

(2) Production of photosensitive resin composition 10 g of the purified polymer # 1 was weighed into a 100 mL glass container, 40 g of mesitylene, 0.01 g of an antioxidant Irganox 1076 (manufactured by Ciba Geigy), and dimethylbis (norbornenemethoxy). Silane (SiX) 2.4g, the above catalyst precursor (2.6E-2g), photoacid generator Rhodosil Photoinitiator 2074 (manufactured by Rhodia, CAS # 178233-72-2) (1.36E-2g, in ethyl acetate 0.1mL) ) And uniformly dissolved, followed by filtration with a 0.2 μm PTFE filter to obtain a clean photosensitive resin composition varnish.

(3) Production of optical waveguide film (production of lower clad layer)
A lower clad layer similar to that in Example 1 was produced.

(Formation of core layer)
The varnish prepared on the lower clad layer was uniformly applied by a doctor blade, and then placed in a 45 ° C. dryer for 15 minutes. After completely removing the solvent, a photomask was pressed and selectively irradiated with ultraviolet rays at 500 mJ / cm ² . The mask was removed, and heating was performed in three stages in a dryer at 45 ° C. for 30 minutes, 85 ° C. for 30 minutes, and 150 ° C. for 1 hour. It was confirmed that a waveguide pattern appeared after heating. Moreover, formation of the core part and the clad part was confirmed.

(Formation of upper cladding layer)
An upper clad layer similar to that in Example 1 was produced.

(4) Evaluation Evaluation was performed in the same manner as in Example 1. The propagation loss could be calculated as 0.05 dB / cm. The difference in refractive index between the core portion and the cladding portion was 0.005.

B. Evaluation of Optical Waveguide The following evaluations were performed on the optical waveguides obtained in the examples and comparative examples. The evaluation items are shown together with the contents. The obtained results are shown in Table 2.

1. Light loss Light emitted from an 850 nm VCSEL (surface emitting laser) was introduced into the optical waveguide via a 50 μmφ optical fiber, and received by a 200 μmφ optical fiber to measure the light intensity. The cutback method was used for the measurement, and the waveguide length was plotted on the horizontal axis and the insertion loss was plotted on the vertical axis. The measured values were neatly arranged on a straight line, and the propagation loss was calculated from the slope.

2. Heat resistance The optical waveguide was placed in a high-temperature and high-humidity tank (85 ° C., 85% RH), and propagation loss after 500 hours of wet heat treatment was evaluated. It was also confirmed in parallel presence or absence of degradation of the propagation loss due to reflow process (N ₂ atmosphere, a maximum temperature of 260 ° C. / 60 seconds).
Note that the measurement of the propagation loss here is the same as the one optical loss measurement method.

3. Bending loss of optical waveguide The bending loss of the light intensity of the optical waveguide film having a radius of curvature of 10 mm was evaluated. Light emitted from an 850 nm VCSEL (surface emitting laser) was introduced into the end face of the optical waveguide film via a 50 μmφ optical fiber, and the light intensity was measured from the other end with a 200 μmφ optical fiber (see the following formula) ). The increment of the loss that occurs when the optical waveguide film having the same length is bent is defined as “bending loss”. As shown in FIG. 19, the insertion loss and the optical waveguide film are linear when the optical waveguide film is curved. The “bending loss” is expressed by the difference from the insertion loss when the shape is made.

Insertion loss [dB] =-10 log (emitted light intensity / incident light intensity)
Bending loss = (insertion loss in a curve)-(insertion loss in a straight line)

  As is apparent from Table 2, Examples 1 and 8-12 showed low optical loss and excellent optical waveguide performance.

  In addition, Examples 1 and 8-12 showed that even without a coating layer, the light loss after high-temperature and high-humidity treatment and after reflow treatment was small, and the heat resistance was excellent.

  In particular, Examples 1, 8, 9, and 10 have a small bending loss, and it was suggested that sufficient performance was exhibited even when the optical waveguide was bent.

  Furthermore, the coating layer comprised with the flame retardant material was formed so that the optical waveguide film obtained by each Example and the comparative example might be covered.

  In addition, the thing which coat | covered the optical waveguide film with the coating layer using the polyimide resin shown below as a flame retardant, and the thing which coat | covered the optical waveguide film with the coating layer using the polyamide resin shown below were formed. .

(Polyimide resin)
Polyamideimide (Toyobo, Viromax NX-100) was dissolved in tetrahydrofuran to prepare a polyimide resin liquid material. Next, an optical waveguide film was immersed in this liquid material. Then, the coating layer was obtained by taking out the optical waveguide film and drying and solidifying the liquid material. In addition, the average thickness of the obtained coating layer was 100 micrometers. Moreover, the flame retardance by the UL-94 test of the used polyamideimide was V-0.

  In addition, as a polyimide-type resin, the thing containing a flame-retardant filler (silica particle with an average particle diameter of 5 micrometers) and the thing which does not contain were prepared, and the optical waveguide film with a coating layer was manufactured about each.

(Polyamide resin)
Semi-aromatic polyamide (manufactured by Kuraray, Genesta GN2330) was dissolved in tetrahydrofuran to prepare a liquid material of polyamide-based resin. Next, an optical waveguide film was immersed in this liquid material. Then, the coating layer was obtained by taking out the optical waveguide film and drying and solidifying the liquid material. In addition, the average thickness of the obtained coating layer was 100 micrometers. Moreover, the flame retardance by the UL-94 test of the used semi-aromatic polyamide was V-0.

  In addition, as a polyamide-type resin, the thing containing a flame-retardant filler (silica particle with an average particle diameter of 5 micrometers) and the thing which does not contain were prepared, and the optical waveguide film with a coating layer was manufactured about each.

  Subsequently, about the obtained optical waveguide film with a coating layer, the reflow process in the said heat resistance test was given, and the presence or absence of deterioration of a propagation loss was confirmed.

  As a result, in all the optical waveguide films in which the coating layer was formed, an improvement in heat resistance was recognized as compared with the optical waveguide film in which the coating layer was not formed. In particular, the optical waveguide film obtained in the comparative example showed a significant improvement in heat resistance, but still did not significantly affect the heat resistance of the optical waveguide film obtained in the examples.

  Moreover, when the flame retardant filler-containing one was compared with the one containing no flame-retardant filler, it became clear that in any of the optical waveguide films with a coating layer, the one containing the flame retardant filler was superior in heat resistance. It was.

DESCRIPTION OF SYMBOLS 1 Optical waveguide structure 2 Substrate 21 Through-hole 22 Conductor post 23 Through-hole 3 Light emitting element 30 Base 31 Light emitting part 32 Metal wire 33 External electrode 35 Light emitting IC (drive element)
300 Light emitting circuit (optical transmitter)
4 light receiving element 40 base 41 light receiving part 42 metal wire 43 external electrode 45 light receiving IC (amplifying element)
400 Light receiving circuit (light receiving part)
DESCRIPTION OF SYMBOLS 5 Conductor layer 7 Covering layer 9 Optical waveguide 91 Clad layer 92 Clad layer 93 Core layer 94 Core part 95 Clad part 97 Optical path conversion part 98 Optical wiring 900 Varnish 910 Film M Mask

Claims (28)

An optical waveguide having a core portion and a cladding portion having different refractive indexes, and a coating layer provided to cover the optical waveguide and made of a flame retardant material,
The core part is
(A) a cyclic olefin resin;
(B) The refractive index is different from that of (A), and at least one of a monomer having a cyclic ether group and an oligomer having a cyclic ether group;
(C) a photoacid generator;
An optical waveguide structure characterized by being formed into a desired shape by selectively irradiating active radiation to a core layer composed of a composition comprising:   The optical waveguide structure according to claim 1, wherein the cyclic ether group (B) is an oxetanyl group or an epoxy group.   The optical waveguide structure according to claim 1 or 2, wherein the cyclic olefin resin (A) is a norbornene resin. (B) has a lower refractive index than (A),
2. The cyclic olefin resin has a leaving group that is detached by an acid generated from the photoacid generator (C) and lowers the refractive index of (A) by the elimination. 4. The optical waveguide structure according to any one of 3 above. The cyclic olefin resin (A) has a leaving group that is eliminated by an acid generated from the photoacid generator (C) in the side chain,
The optical waveguide structure according to claim 2, wherein (B) includes the first monomer represented by the following formula (100).

  6. The optical waveguide structure according to claim 5, wherein (B) further contains at least one of the epoxy compound and the oxetane compound having two oxetanyl groups as a second monomer.   The optical waveguide according to claim 6, wherein a ratio of the second monomer to the first monomer is 0.1 to 1.0 in a weight ratio (weight of the second monomer / weight of the first monomer). Structure.   The optical waveguide structure according to claim 4, wherein the leaving group has at least one of an —O— structure, an —Si—aryl structure, and an —O—Si— structure. .   9. The optical waveguide structure according to claim 5, wherein the cyclic olefin resin (A) is a norbornene resin.   The optical waveguide structure according to claim 9, wherein the norbornene-based resin is an addition polymer of norbornene. The optical waveguide structure according to claim 10, wherein the addition polymer of norbornene has a repeating unit represented by the following formula (101).

[N in the formula is an integer of 0 or more and 9 or less. ] The optical waveguide structure according to claim 10 or 11, wherein the norbornene addition polymer has a repeating unit represented by the following formula (102).

  The optical waveguide according to any one of claims 5 to 12, wherein the content of the first monomer represented by the formula (100) is 1 part by weight or more and 50 parts by weight or less with respect to 100 parts by weight of the cyclic olefin resin. Structure.   The optical waveguide structure according to any one of claims 1 to 13, wherein the concentration of the structure derived from (B) is different between a region irradiated with active radiation of the core layer and a non-irradiated region.   The optical waveguide structure according to any one of claims 1 to 14, wherein a difference in refractive index between an area irradiated with active radiation and an unirradiated area of the core layer is 0.01 or more.   The optical waveguide structure according to any one of claims 1 to 15, wherein a region of the core layer irradiated with actinic radiation is at least a part of the cladding part, and an unirradiated region is at least a part of the core part.   The optical waveguide structure according to claim 1, wherein the flame retardant is a resin material containing a polyimide resin or a polyamide resin.   The optical waveguide structure according to claim 17, wherein the coating layer is formed by applying the liquid resin material so as to cover the optical waveguide and then curing the resin material.   The optical waveguide structure according to any one of claims 1 to 18, wherein the flame retardant has a flame retardance of HB or more according to a UL-94 test.   The optical waveguide structure according to claim 1, wherein the flame retardant includes a flame retardant filler having flame retardancy.   21. The optical waveguide structure according to claim 1, wherein an average thickness of the coating layer is 10 to 200 [mu] m. A first support member for supporting one end of the optical waveguide; and a light emitting element provided on the first support member, wherein the one end of the optical waveguide and the light emitting part of the light emitting element are optically connected. An optical transmitter configured to be connected to,
A second support member for supporting the other end of the optical waveguide; and a light receiving element provided on the second support member; and the other end of the optical waveguide and the light receiving unit of the light receiving element. An optical receiver configured to be optically connected,
The optical waveguide structure according to any one of claims 1 to 21, wherein at least one of the light emitting element and the light receiving element is covered with the covering layer. The optical transmission unit further includes a driving circuit provided on the first support member for driving the light emitting element,
The optical receiver is further provided with an amplifying circuit provided on the second support member for amplifying a signal obtained from the light receiving element,
The optical waveguide structure according to claim 22, wherein at least one of the driving circuit and the amplification circuit is covered with the covering layer. Furthermore, it is provided on at least one surface side of the optical waveguide, and has a conductor layer in which electrical wiring is formed,
The optical waveguide structure according to any one of claims 1 to 23, wherein the conductor layer is covered with the covering layer. The optical waveguide has an optical path conversion part that bends the optical path of the core part in the middle of the longitudinal direction,
Of the longitudinal direction of the optical waveguide, at least a part of either side sandwiching the optical path conversion unit and not optically connected to the optical path conversion unit is made of the constituent material of the optical waveguide. The optical waveguide structure according to any one of claims 1 to 24, which is made of a carbonized material.   26. The optical waveguide structure according to claim 25, wherein a side of the optical waveguide that is not optically connected to the optical path conversion unit is configured only by a material obtained by carbonizing a constituent material of the cladding unit. The conductor layer is provided on one surface side of a flexible substrate having flexibility, and constitutes a wiring substrate together with the flexible substrate,
27. The optical waveguide structure according to claim 1, wherein the wiring board is covered with the covering layer.   An electronic apparatus comprising the optical waveguide structure according to any one of claims 1 to 27.

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