JP5071496B2 - Optical waveguide structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical waveguide structure wherein an electric circuit and an optical circuit are constructed with highly flexibly designed patterns respectively, an optical path with high dimensional precision can be formed by a simple method, and a highly durable optical waveguide is installed. <P>SOLUTION: The optical waveguide structure 1 includes a substrate 2, an optical waveguide 9 wherein both sides of a core layer 93 are laminated with clad layers 91 and 92, conductor layers 51 and 52 joined to both sides respectively, an optical path conversion part 96 bending the optical path of the optical waveguide 9 at right angles substantially, a light emitting element 10, and an electrical element 12. In the inner circumferential surface of a through hole 22 formed in the substrate 2, a conductor part 3 is formed, and on the inside of the conductor part 3, a vertical optical waveguide 23 formed of a core part 24 and a clad part 25 is formed. The core layer 93 has a core part 94 and a clad part 95. The core part 94 is formed into a desired shape by selectively radiating active radiation to the core layer 93 formed of a material having a refraction index varying by radiation of active radiation and heating. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to an optical waveguide structure.

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. Has been actively conducted.

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 predetermined electric wiring circuit and an optical waveguide composed of a core part and a cladding part are formed on a substrate, and a light emitting element and a light receiving element are attached to this optical waveguide (electrical element) / Optical hybrid substrate) is disclosed (for example, see 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. When combined with an electrical wiring pattern, the degree of freedom in designing the wiring pattern is narrow. If priority is given to the design of the electrical wiring pattern, the degree of freedom in designing the optical path of the optical waveguide is reduced.
4). It is disadvantageous for integration and miniaturization.

JP 2004-146602 A

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

Such an object is achieved by the present inventions (1) to (2) below.
(1) a substrate having a rigid or flexible, is composed of a laminated structure having an optical waveguide having a core part and a cladding part the refractive indices are different, and the conductor layer, and
A through hole penetrating the substrate in the thickness direction;
A light guide provided in the through hole and optically connected to the core portion;
Wherein provided in the through hole, a waveguide structure that have a, a conductor portion electrically connected to the conductor layer,
The optical waveguide is formed by laminating a first cladding layer, a core layer including the core portion and the cladding portion, and a second cladding layer in this order,
The core layer, leaving the photoacid generator, at least a portion of the by Ri molecular structure to the action of the photoacid generator which is branched and active activatable from the main chain and the main chain may be disengaged from the main chain Forming a layer containing a polymer having a functional group and a monomer compatible with the polymer and having a refractive index lower than that of the polymer, and then selectively irradiating the active radiation to the layer , In the irradiation region irradiated with the active radiation, the photoacid generator is activated, the leaving group of the polymer is released, and the monomer in the irradiation region is irradiated with the active radiation and heated. As the reaction of the monomer proceeds, the unreacted monomer gathers from the non-irradiated region where the actinic radiation is not irradiated, resulting in a difference in refractive index between the irradiated region and the non-irradiated region. The Rukoto, the irradiated region and the cladding part state, and are not the non-irradiated region was obtained as the core portion,
Each of the first cladding layer and the second cladding layer is a non-absorbing photobase as a substance that is activated by irradiation with actinic radiation or heat and is not activated when the photoacid generator is activated. An optical waveguide structure comprising: a generator or a thermal base generator; a polymer having a leaving group; and a monomer compatible with the polymer and having a refractive index lower than that of the polymer .

(2) The optical waveguide structure according to (1), wherein the monomer contained in the core layer is capable of causing a polymerization reaction or a crosslinking reaction in the polymer.

According to the present invention, the core portion can be patterned by a simple method of irradiation with actinic radiation (active energy ray, electron beam, X-ray, etc.), and the pattern shape of the core portion constituting the optical path of the optical circuit can be obtained. A core portion with a wide design freedom and high dimensional accuracy can be obtained.

In addition, when the core layer is made of a desired material, when the stress is applied to the optical waveguide or deformation occurs, particularly even when repeatedly curved and deformed, delamination between the core portion and the cladding portion, Defects such as the occurrence of microcracks in the core are unlikely to occur, and as a result, the optical transmission performance of the optical waveguide is maintained and the durability is excellent.

Furthermore, when the core part is composed of a resin composition mainly composed of a norbornene resin (cyclic olefin resin), the core part and the cladding part are highly effective in that they are particularly strong against the deformation and hardly cause defects. The difference in refractive index of the optical waveguide can be further increased, and the optical waveguide is excellent in heat resistance. As a result, an optical waveguide having higher performance and durability is obtained.

In addition, since the optical waveguide and the optical circuit have a light guide path extending in the thickness direction of the laminated structure, it is possible to design a three-dimensional circuit for both the electric circuit and the optical circuit, and the degree of design freedom is increased in each circuit design. . In particular, by arranging the light guide path and the conductor portion together, particularly by forming both in the through hole, it contributes to the integration and miniaturization of the optical waveguide structure.

In addition, when the optical path conversion unit is provided, the optical path of the transmission light can be bent in a desired direction, which increases the degree of freedom in designing the optical path and contributes to the integration of the optical circuit.

In the case of having a lens portion, transmission light can be condensed and diffused as necessary in the optical path, and the degree of freedom in designing the optical circuit is further expanded in combination with the bending of the optical path.

When the optical waveguide structure has an element (light emitting element or light receiving element), the light emitted from the light emitting portion of the element is guided to another place by the optical waveguide by being optically connected to the optical waveguide, or Light from other places can be guided to the light receiving portion of the element by the optical waveguide, a small and integrated optical circuit can be formed, and the operation reliability of the optical circuit is also high.

In addition, by having a conductor layer and a conductor portion conducting to the conductor, for example, wiring to the element can be easily performed, and wiring suitable for it is possible regardless of the type of element (terminal installation location). It is rich in versatility. Moreover, such a wiring circuit pattern has a wide degree of freedom in design (for example, a degree of freedom in selection of a terminal installation location).

Such an optical waveguide structure of the present invention has a wide range of design of optical circuits (patterns of optical waveguides and light guides) and electrical circuits (patterns of conductor layers and conductors), good yield, and optical transmission performance. Is highly reliable, durable and versatile. Therefore, the optical waveguide structure of the present invention can be used for various electronic components, electronic devices, and the like.

By using the optical waveguide structure of the present invention, at least one conductor layer in which an electric circuit is formed and at least one optical waveguide in which an optical path is arranged one- or two-dimensionally in a plane direction are laminated. A multilayer optical / electrical hybrid (fusion) wiring board can be manufactured, and the wiring between layers (in the thickness direction of the layer) is made through a through-hole having both a light guide path and a conductor portion. However, connection (signal transmission / reception) is possible even in an optical circuit, and as a result, a three-dimensional optical / electrical hybrid substrate with a wide degree of freedom in circuit design can be provided.

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. The device can be downsized.

It is sectional drawing which shows 1st Embodiment of the optical waveguide structure of this invention. It is sectional drawing which shows 2nd Embodiment of the optical waveguide structure of this invention. It is sectional drawing which shows 3rd Embodiment of the optical waveguide structure of this invention. It is sectional drawing 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 the sectional view on the AA line in FIG. FIG. 5 is a sectional view taken along line BB in FIG. 3. It is CC sectional view taken on the line in FIG. It is sectional drawing which shows typically the process example of the 1st manufacturing method of the optical waveguide in this invention. It is sectional drawing which shows typically the process example of the 1st manufacturing method of the optical waveguide in this invention. It is sectional drawing which shows typically the process example of the 1st manufacturing method of the optical waveguide in this invention. It is sectional drawing which shows typically the process example of the 1st manufacturing method of the optical waveguide in this invention. It is sectional drawing which shows typically the process example of the 1st manufacturing method of the optical waveguide in this invention. It is sectional drawing which shows typically the process example of the 4th manufacturing method of the optical waveguide in this invention. It is sectional drawing which shows typically the process example of the 4th manufacturing method of the optical waveguide in this invention. It is sectional drawing which shows typically the process example of the 4th manufacturing method of the optical waveguide in this invention. It is sectional drawing which shows typically the process example of the 4th manufacturing method of the optical waveguide in this invention. It is sectional drawing which shows typically the process example of the 4th manufacturing method of the optical waveguide in this invention.

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

1 to 5 are cross-sectional views showing an embodiment of the optical waveguide structure of the present invention, and FIGS. 6, 7 and 8 are cross-sectional views taken along line AA in FIG. 6 is a cross-sectional view taken along line BB in FIG. 3 and a cross-sectional view taken along line CC in FIG. Hereinafter, a configuration example of the optical waveguide structure will be described with reference to these drawings. In the following description, the upper side in FIGS. 1 to 5 is “upper” or “upper”, and the lower side is “lower” or “lower”. 1 to 5 are exaggerated in the layer thickness direction (vertical direction in each figure).

<First Embodiment: FIG. 1>
As shown in FIG. 1, the optical waveguide structure 1 of the present invention includes a substrate 2, an optical waveguide 9 provided adjacent to the substrate 2, and conductor layers 51 and 52 bonded to both surfaces of the optical waveguide 9, respectively. An optical path conversion unit 96 that bends the optical path of the optical waveguide 9, a conductor layer 53 bonded to the upper surface of the substrate 2, the light emitting element 10, and the electric element 12.

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, polybenzoxazole resin. And resin materials such as norbornene resin and semiconductor materials such as silicon, gallium / arsenic, indium / phosphorus, germanium, silicon carbide, and silicon germanium. These materials may be used alone or in combination.

Further, the substrate 2 may be, for example, a fiber base material (woven fabric, non-woven fabric, woven fabric, knitted fabric, etc.) such as glass fiber or resin fiber impregnated with the above-described resin material (prepreg, etc.). For example, a glass cloth impregnated with an epoxy resin is called a glass epoxy substrate, but such a substrate can be used as the substrate 2. Substrate 2 including such a fiber base is
Even if it is relatively thin, it has high strength and has a low coefficient of thermal expansion, which is particularly advantageous when the optical waveguide 9 or a conductor layer (metal layer) is bonded to the substrate 2.

Moreover, the board | substrate 2 may be a laminated body of a some layer. For example, a laminate of a first layer and a second layer made of resin materials having different compositions (kinds), a layer (sheet material) in which the fiber base material is impregnated with a resin material, and a resin material The thing which laminated | stacked the layer 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, About 10 micrometers-about 1.2 mm are preferable normally,
About 50-600 micrometers is more preferable.

The substrate 2 may be hard (rigid) or flexible (flexible). Moreover, you may have both a hard board | substrate and a flexible board | substrate. In this case, the optical waveguide 9 may be formed on at least one of a hard substrate and a flexible substrate,
It may be formed across both.

An optical waveguide 9 is bonded to the lower surface of the substrate 2. The optical waveguide 9 is formed by laminating a clad layer 91, a core layer 93, and a clad layer 92 in this order from the lower side in FIG. 1. The core layer 93 includes a core portion 94 and a clad portion 95 having a predetermined pattern. Is formed.

The core portion 94 has a higher refractive index than that of the cladding portion 95, and also 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 this configuration, the core portion 94
Functions as an optical path of the transmission light 18 surrounded by the clad portion on the entire outer periphery.

In the configuration shown in FIG. 1, a core portion 94 is formed on the left side in FIG. 1 of a later-described reflective surface 961 of the core layer 93, and a cladding portion 95 is formed on the other portion of the core layer 93. .

As a constituent material of the core layer 93, a material whose refractive index is changed by irradiation with active radiation (active energy ray, electron beam, X-ray or the like) or further heating is used.
Preferable examples of such materials include those mainly composed of a resin composition containing a cyclic olefin-based resin such as a benzocyclobutene-based tree polymer or a norbornene-based polymer (resin), including a norbornene-based polymer ( The main 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 sum of two or more) is the core layer 93.
About 0.5 to 40% by weight is preferable, and about 3 to 30% by weight is more preferable with respect to the entire constituent material. If this amount is too small, the function of the additive cannot be sufficiently exhibited. If the amount is too large, depending on the type and characteristics of the additive, the light transmitted through the core portion 94 (transmitted light 18) is transmitted. There is a risk of decreasing the rate, 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 actinic radiation using a mask to pattern the core portion 94 having a desired shape.

Examples of the active radiation used for exposure include active energy rays such as visible light, ultraviolet light, infrared light, and laser light, electron beams, and X-rays. The electron beam can be irradiated with an irradiation amount of, for example, about 50 to 2000 KGy.

In the core layer 93, the refractive index of the portion irradiated with active radiation changes (the core layer 9).
(3) the refractive index may increase or decrease), and a difference in refractive index may occur between the portion not irradiated with actinic radiation. For example, the portion of the core layer 93 that has been irradiated with active radiation becomes the cladding portion 954, and the portion that has not been irradiated becomes the core portion 94. Also,
The reverse is also true. 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 actinic radiation in a predetermined pattern and then heating. By adding this heating step, the core portion 94 is obtained.
And the difference in refractive index between the clad portion 95 and the clad portion 95 is more 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 diffusion part (a part where the width or the like is increased), or two of these
Any shape such as a combination of the above may be used. The feature of the present invention is that the core portion 94 having any shape can be easily formed by setting the irradiation pattern of the active radiation.

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 conductor layer 51 bonded to the lower surface of the optical waveguide 9, the conductor layer 52 bonded to the upper surface, and the conductor layer 53 bonded to the upper surface of the substrate 2 are each patterned into a predetermined shape to obtain a desired wiring. Or it constitutes a circuit. Examples of the constituent material of the conductor layers 51 to 53 include various metal materials such as copper, a copper-based alloy, aluminum, and an aluminum-based alloy. Although the thickness of the conductor layers 51-53 is not specifically limited, Each is normally 3-12.
About 0 μm is preferable, and about 5 to 70 μm is more preferable.

The conductor layers 51-53 are formed by methods, such as joining (adhesion) of metal foil, metal plating, vapor deposition, sputtering, etc., for example. For example, etching, printing, masking, or the like can be used for patterning the conductor layers 51-53.

The light emitting element 10 has a light emitting unit 101 and a pair of terminals 103 and 105 on the lower surface side thereof. The light emitting unit 101 is located between the terminal 103 and the terminal 105. Terminal 103, 1
When power is applied during 05, the light emitting unit 101 emits light.

In addition, the light emitting part in the light emitting element 10 may be configured by one light emitting point, or may be a group of a plurality of light emitting points. As a set of a plurality of light emitting points, for example, the light emitting points are arranged in a row (for example, 1 × 4, 1 × 12) or a matrix (for example, the light emitting points are n × m
(Pieces: n and m are integers of 2 or more) and those in which a plurality of light emitting points are arranged randomly (irregularly). The same applies to a light receiving portion in a light receiving element to be described later.

In the light emitting element 10, the terminals 103 and 105 are portions 531 and 5 of the conductor layer 53, respectively.
It is mounted on the substrate 2 so as to be joined (electrically connected) to 32.

The electric element (electronic circuit element) 12 is composed of, for example, a semiconductor element (semiconductor chip). Although the function of the electric element 12 is not particularly limited, an example is one that constitutes a circuit for driving the light emitting element 10. The electric element 12 has two terminals 123 and 125 on the lower surface side.

In the electric element 12, the terminals 123 and 125 are portions 532 and 5 of the conductor layer 53, respectively.
It is mounted on the optical waveguide 9 so as to be joined (electrically connected) to 33.

The lower part including the terminals 103, 105, 123, and 125 of the light emitting element 10 and the electric element 12 is sealed with the underfill material 4. As a result, the gap between the light emitting element 10 and the electric element 12 and the optical waveguide 9 is sealed with the underfill material 4 without forming a gap. Further, the entire light emitting element 10 and electric element 12 (outer surface) are covered and sealed with the sealing material 6. As described above, the light emitting element 10 and the electric element 12 are entirely sealed, and in particular, the light emitting portion 101 is sealed without being exposed to the outside, so that it is protected from dirt, damage, oxidative degradation, and the like. Contributes to improving the reliability of electronic components.

The underfill material 4 is made of a material that substantially transmits light (transmitted light 18) emitted from the light emitting unit 101, and is preferably made of a transparent material.

As a constituent material of the underfill material 4, an insulating resin material is preferable, and examples thereof include an epoxy resin, a phenol resin, a urethane resin, and a polyimide resin.

Moreover, as a constituent material of the sealing material 6, an insulating resin material is preferable, and examples thereof include an epoxy resin, a phenol resin, a norbornene resin, and a silicon resin.

As shown in FIG. 1, the optical waveguide 9 has a through hole (through hole or via hole) 8 penetrating in the thickness direction. The through-hole 8 is filled with a conductive material (for example, various metal materials such as copper, a copper-based alloy, aluminum, an aluminum-based alloy), and a conductor post (
Conductor portion) 81 is formed. Predetermined portions of the conductor layer 51 and the conductor layer 52 are electrically connected via the conductor post 81. That is, it is possible to energize each terminal of the light emitting element 10 and the electric element 12 by the conductor layer 51 on the lower surface side of the optical waveguide 9 and the conductor layer 53 (parts 531 and 533) on the upper surface side of the substrate 2. It has become. Terminal 105 and terminal 1
23 is conducted, and these are connected to the ground side.

The optical waveguide 9 has an optical path conversion part 96 that bends the optical path of the core part 94. The optical path conversion unit 96 is a connection part between the core part 94 and the light guide path 24 described later, that is, the core part 94 shown in FIG.
It is provided at the middle right end portion and at the lower end portion of the light guide path 24. Thereby, an optical path can be bent efficiently and reliably.

The optical path changing unit 96 is a reflecting surface (mirror) 96 that reflects at least a part of the transmission light 18.
1 is composed. The reflecting surface 961 is provided at a position directly below the light emitting unit 101.

The reflection surface 961 is approximately 45 ° with respect to the optical path of the optical waveguide 9, that is, the longitudinal direction of the core portion 94.
It is inclined and has a function of reflecting most of the transmitted light 18 (for example, 90% or more).

Such an optical path conversion unit 96 is formed by removing (deleting) a part of the optical waveguide 9 to form, for example, a concave portion having a triangular cross section, and using one inclined surface as the reflecting surface 961. The reflection surface 961 may have a reflection film such as a multilayer optical thin film or a metal thin film (for example, an aluminum vapor deposition film) or a reflection increasing film. In addition, although not shown, the concave portion of the optical path conversion unit 96 may be filled with a filler having translucency with respect to the transmission light 18.

In the configuration shown in the figure, the reflection surface 961 (the optical path conversion unit 96) is formed across the clad layer 91, the core layer 93, and the clad layer 92, but may be formed only in the core layer 93. Further, a mirror component such as a prism, a mirror mirror, or a silicon mirror may be used.

A through hole 22 penetrating the substrate 2 is formed at a position directly below the light emitting unit 101 in the substrate 2. The cross-sectional shape of the through hole 22 is not particularly limited, but in the present embodiment, it is circular (see FIG. 6). Other shapes include, for example, an ellipse, an oval, and a rectangle (rectangle)
, Hexagons, and irregular shapes.

On the inner peripheral surface of the through-hole 22, a layer (conductor portion 3) made of a conductive material (metal material) similar to that of the conductor layer 51 is formed. With this conductor portion 3, it becomes possible to send an electrical signal or the like in the thickness direction of the substrate 2 (hereinafter also simply referred to as “thickness direction”). In FIG. 6, the conductor portion 3 is formed over the entire circumference of the inner peripheral surface of the through hole 22 (in a ring shape), but may be partially formed in the circumferential direction.

The conductor portion 3 is formed substantially perpendicular to the substrate 2. However, not limited to this,
The conductor portion 3 may be formed to be inclined at a predetermined angle with respect to the substrate 2, or the conductor portion 3
May be deformed (bent, curved, branched, etc.).

As a method for forming the conductor portion 3, for example, a method of bonding (adhering) a metal foil to the inner surface of the through hole 22, a method of forming a metal layer on the inner surface of the through hole 22 by a method such as metal plating, vapor deposition, sputtering, Examples thereof include a method in which a metal paste containing a metal filler is applied and heated (fired, cured, etc.) to form a metal layer.

The upper end portion of the conductor portion 3 is electrically connected to the portion 532 of the conductor layer 53, and the lower end portion of the conductor portion 3 is electrically connected to a predetermined portion of the conductor layer 52. Thereby, via the conductor part 3,
Electrical signals can be exchanged between the conductor layers 52 and 53 formed at different positions in the thickness direction.

In addition, the portion inside the through hole 22 inside the conductor portion 3 constitutes a light transmitting portion that transmits the transmission light 18. That is, this portion becomes a light guide path 24 that guides (transmits) the transmission light 18 in the thickness direction of the substrate 2. In other words, the conductor portion 3 is formed so as to surround the periphery of the light guide path 24. Thereby, the light guide path 24 and the conductor part 3 can be efficiently arranged in the through hole 22 having a limited size (inner diameter).

The light guide 24 is formed substantially perpendicular to the substrate 2. However, the present invention is not limited thereto, and the light guide path 24 may be formed to be inclined at a predetermined angle with respect to the substrate 2, or a part of the light guide path 24 may be deformed (curved, branched, etc.).

A portion inside the conductor portion 3 in the through hole 22 may be a cavity, but in this portion, a light-transmitting filler, that is, the transmittance of the transmitted light 18 is 80% or more, preferably 90% or more. ,
More preferably, the filler is filled with 95% or more of the material. This filler can be the same material as the core portion 94 of the core layer 93. As a result, the light guide (
The core portion 24 can be easily formed, and the same advantages as the core portion 94 described later can be obtained. Further, this filler may be the same material as the clad portion 95 of the core layer 93 or the same material as the clad layer 91 or 92.

In the through hole 22, the conductor portion 3 and the light guide path 24 are in contact with each other. However, the present invention is not limited to this. For example, the conductor section 3 and the light guide path 24 are not shown in an intermediate layer (adhesive layer, insulating layer, etc.). It may be configured such that they are approaching each other.

The inner diameter of the through hole 22 is not particularly limited, but is usually preferably about 0.05 to 2 mm,
About 0.1 to 0.5 mm is more preferable.

Moreover, the outer diameter of the light guide path (core part) 24 is not particularly limited, but is usually 0.005 to 0.00.
About 3 mm is preferable and about 0.02 to 0.15 mm is more preferable.

As described above, since the conductor portion 3 extending in the thickness direction and the light guide path 24 are formed adjacent to each other, an electric signal and an optical signal are transmitted in the thickness direction through one through hole 22. be able to.

In the optical waveguide structure 1 of the present embodiment, when energization is performed between the conductor layer 51 and the part 531 of the conductor layer 53, the conductor layer 51 and the terminal 105 are electrically connected via the conductor part 3 and the part 532. Therefore, energization is performed between the terminals 103 and 105 of the light emitting element 10, and the light emitting unit 101 is turned on. The transmission light 18 emitted downward in FIG. 1 due to the lighting of the light emitting part 101 passes through the underfill material 4, passes through the light guide path 24 (core part 24) in the through hole 22, and is reflected by the reflecting surface 961. The core portion 94 is bent by 90 °, enters the core portion 94 of the optical waveguide 9, and repeats reflection at the interface with the cladding portion (cladding layers 91 and 92 and the side (clad portion 95 in FIG. 1)). It progresses along the longitudinal direction (the left direction in FIG. 1) in 94.

Second Embodiment: FIG. 2
FIG. 2 shows a second embodiment of the optical waveguide structure 1 of the present invention. Hereinafter, although this optical waveguide structure 1 is demonstrated, about the matter (a structure, an operation | movement, etc.) similar to the said 1st Embodiment, the description is abbreviate | omitted and it demonstrates centering around difference.

The optical waveguide structure 1 of the present embodiment is different from the first embodiment in the configuration of the light transmitting portion (near the through hole 22) of the substrate 2, and is otherwise the same as in the first embodiment. That is, the through hole 2 of the substrate 2
2 is formed with a conductor portion 3 and a light guide path 24 similar to those described above, but a lens portion 26 capable of condensing or diffusing the transmission light 18 is provided below the through hole 22. .

That is, a lens portion 26 formed of a convex lens (more precisely, a plano-convex lens) is provided at the lower end of the light guide path 24 (the emission side of the transmission light 18).

As a result, the transmission light 18 emitted from the light emitting unit 101 downward in FIG. 2 passes through the underfill material 4, passes through the light guide path 24, and is collected by the lens unit 26, and the light beam (beam). The light beam is reflected by the reflecting surface 961 and bent by 90 °, enters the core portion 94 of the optical waveguide 9, and advances in the core portion 94 along the longitudinal direction (left direction in FIG. 2).

By providing such a lens portion 26, clearer (sharp) transmitted light can be obtained, and more excellent light transmission characteristics can be obtained.

The lens unit 26 may be capable of diffusing the transmission light 18. In this case, a concave lens may be used.

A material different from the refractive index of the light guide path 24 may be used as the material of the lens constituting the lens unit 26. Depending on whether the refractive index of the lens material is higher or lower than the refractive index of the light guide path 24, the function of the lens portion 26 can be set to either a condensing lens or a diffusing lens.

Further, the installation position of the lens unit 26 is not limited to the position illustrated in FIG. 2, and may be, for example, in the middle or upper end of the light guide path 24 (through hole 22), or may be incident on another part, for example, the core unit 94. It may be a side end or an emission side end.

<Third Embodiment: FIG. 3>
FIG. 3 shows a third embodiment of the optical waveguide structure 1 of the present invention. Hereinafter, although this optical waveguide structure 1 is demonstrated, about the matter (a structure, an operation | movement, etc.) similar to the said 1st Embodiment, the description is abbreviate | omitted and it demonstrates focusing on difference.

The optical waveguide structure 1 of the present embodiment is different from the first embodiment in the configuration of the light transmitting portion (near the through hole 22) of the substrate 2, and is otherwise the same as in the first embodiment. That is, the through hole 2 of the substrate 2
2 is formed with a conductor portion 3 similar to the above, and a vertical optical waveguide 23 is formed inside thereof.

The vertical optical waveguide 23 includes a core portion 24 and a clad portion 25 that surrounds the outer periphery of the core portion 24. The core part 24 has a higher refractive index than the cladding part 25. By forming such a vertical optical waveguide 23 in the through hole 22, the conductor portion 24 in the first embodiment is used.
As compared with the above, the loss of light quantity due to light leakage or the like is further reduced, and the transmission characteristics of the transmission light 18 are further improved.

The constituent material and the forming method of the core part 24 can be the same as those of the core part 94. Alternatively, the core part 24 may be the same as the light-transmitting filler described in the first embodiment. The constituent material of the cladding part 25 is the cladding part 95 or the cladding layers 91, 92.
And can be similar.

<Fourth Embodiment: FIG. 4>
FIG. 4 shows a fourth embodiment of the optical waveguide structure 1 of the present invention. Hereinafter, although this optical waveguide structure 1 is demonstrated, about the matter (a structure, operation | movement, etc.) similar to the said 1st-3rd embodiment, the description is abbreviate | omitted and it demonstrates centering around difference.

The optical waveguide structure 1 of the present embodiment is the same as that of the third embodiment except that the lens portion 26 is provided. That is, the conductor portion 3 and the vertical optical waveguide 23 similar to those described above are formed in the through hole 22 of the substrate 2, but the transmission light 18 can be condensed or diffused below the through hole 22. A lens portion 26 similar to that described above is provided.

Effects of providing the lens unit 26, lens material constituting the lens unit 26, lens unit 26
The installation position is the same as that described in the third embodiment.

<Fifth Embodiment: FIG. 5>
FIG. 5 shows a fifth embodiment of the optical waveguide structure 1 of the present invention. Hereinafter, although this optical waveguide structure 1 is demonstrated, about the matter (a structure, operation | movement, etc.) similar to the said 1st-4th embodiment, the description is abbreviate | omitted and it demonstrates centering around difference.

The optical waveguide structure 1 of the present embodiment is different from the fourth embodiment in the configuration of the light transmitting portion (near the through hole 22) of the substrate 2, and is otherwise the same as the fourth embodiment. That is, as shown in FIG. 8, the cross-sectional shape of the through hole 22 of the substrate 2 is a shape in which a circular portion 222 and a rectangular portion 224 are combined (
The vertical optical waveguide 23 (or the light guide 24 may be inserted) is inserted in the circular portion 222, and the conductor portion 3 is inserted in the rectangular portion 224. The upper end and lower end of the conductor 3 are
Each is electrically connected to a portion 532 of the conductor layer 53 and the conductor layer 52.

In such a configuration, the volume (volume ratio) of the vertical optical waveguide 23 and the conductor portion 3 can be more accurately defined by setting the cross-sectional area in advance in each of the circular portion 222 and the rectangular portion 224. There is. Further, there is an advantage that the conductor portion 3 can be formed only in a necessary direction in the circumferential direction of the circular portion 222.

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. Moreover, this invention is 1st-1st.
A combination of configurations included in any two or more of the fifth embodiments may be used.

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 manufacturing method>
First, the 1st manufacturing method of the optical waveguide 9 is demonstrated.

FIGS. 9A to 9E are cross-sectional views schematically showing a process example of the first manufacturing method of the optical waveguide.

[1A] First, a layer 910 is formed over a supporting substrate 951 (see FIG. 9A).
The layer 910 is formed by a method in which a core layer forming material (varnish) 900 is applied and cured (solidified).

Specifically, the layer 910 is formed by applying the core layer forming material 900 on the support substrate 951 to form a liquid film, and then placing the support substrate 951 on a ventilated level table so that the surface of the liquid film is not coated. It is formed by leveling the uniform part and evaporating (desolving) the solvent.

When the layer 910 is formed by a coating method, for example, 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,
Examples of the method include a die coating method, but are not limited thereto.

As the support substrate 951, for example, a silicon substrate, a silicon dioxide substrate, a glass substrate, a quartz substrate, a polyethylene terephthalate (PET) film, or the like is used.

The core layer forming material 900 is a photo-induced heat-developable material composed of a polymer 915 and an additive 920 (in this embodiment, at least a monomer, a promoter and a catalyst precursor).
PITDM), a material in which a monomer reaction occurs in the polymer 915 by irradiation with actinic radiation and heating.

In the resulting layer 910, any polymer (matrix) 915 is distributed substantially uniformly and randomly, and the additive 920 is substantially uniformly and randomly dispersed within the polymer 915. ing. Thereby, the additive 920 is substantially uniformly and arbitrarily dispersed in the layer 910.

The average thickness of the layer 910 is appropriately set according to the thickness of the core layer 93 to be formed, and is not particularly limited, but is preferably about 5 to 200 μm, and preferably about 10 to 100 μm. More preferably, it is about 15 to 65 μm.

The polymer 915 has sufficiently high transparency (colorless and transparent) and is compatible with the monomer described later, and the monomer can react (polymerization reaction or crosslinking reaction) as described later. Even after the monomers are polymerized, those having sufficient transparency are preferably used.

Here, “having compatibility” means that the monomer is at least mixed and does not cause phase separation with the polymer 915 in the core layer forming material 900 or the layer 910.

Examples of such a polymer 915 include cyclic olefin resins such as norbornene resins and benzocyclobutene resins, acrylic resins, methacrylic resins, polycarbonate, polystyrene, epoxy resins, polyamides, polyimides, polybenzoxazoles, and the like. Among them, one or a combination of two or more thereof (polymer alloy, polymer blend (mixture), copolymer, etc.) can be used.

Among these, those mainly composed of norbornene resins (norbornene polymers) are preferable. By using a norbornene-based polymer as the polymer 915, the core layer 93 having excellent optical transmission performance and heat resistance can be obtained.

Moreover, since norbornene-type polymer has high hydrophobicity, the core layer 93 which cannot produce the dimensional change by water absorption etc. easily can be obtained.

As norbornene-based polymers, those having a single repeating unit (homopolymer)
Any of those having two or more norbornene-based repeating units (copolymer) may be used.

Examples of such norbornene-based polymers include (1) addition (co) polymers of norbornene monomers obtained by addition (co) polymerization of norbornene monomers, and (2) norbornene monomers and ethylene or α-olefins. (3) addition polymers such as addition copolymers with norbornene-type monomers and non-conjugated dienes, and other monomers as required, (4) ring opening of norbornene-type monomers ( A (co) polymer, 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 ( Co) polymer hydrogenated resin,
(6) a ring-opening copolymer of a norbornene-type monomer and a non-conjugated diene or another monomer,
And a ring-opening polymer such as a polymer obtained by hydrogenating the (co) polymer, if necessary. Examples of these polymers include random copolymers, block copolymers, and alternating copolymers.

These norbornene-based polymers include, for example, ring-opening metathesis polymerization (ROMP), RO
Combination of MP and hydrogenation reaction, polymerization by radical or cation, polymerization using cationic palladium polymerization initiator, polymerization using other polymerization initiator (for example, polymerization initiator of nickel or other transition metal) Etc., and can be obtained by all known polymerization methods.

Among these, as the norbornene-based polymer, those having at least one repeating unit represented by the following chemical formula 1 (Structural Formula B), that is, an addition (co) polymer is preferable.
This is preferable because it is rich in transparency, heat resistance and flexibility.

Such a norbornene polymer is suitably synthesized by using, for example, a norbornene monomer described later (a norbornene monomer represented by Chemical Formula 3 described below or a crosslinkable norbornene monomer).

In order to obtain a polymer 915 having a relatively high refractive index, a monomer having an aromatic ring (aromatic group), a nitrogen atom, a bromine atom or a chlorine atom in the molecular structure is generally selected, A polymer 915 is synthesized (polymerized). On the other hand, the polymer 91 having a relatively low refractive index.
In order to obtain 5, a monomer having an alkyl group, a fluorine atom or an ether structure (ether group) is generally selected in the molecular structure, and a polymer 915 is synthesized (polymerized).

As the norbornene-based polymer having a relatively high refractive index, those containing a repeating unit of aralkylnorbornene are preferable. Such norbornene-based polymers have a particularly high refractive index.

Aralkyl group (arylalkyl group) in the repeating unit of aralkylnorbornene
Examples thereof include benzyl group, phenylethyl group, phenylpropyl group, phenylbutyl group, naphthylethyl group, naphthylpropyl group, fluorenylethyl group, fluorenylpropyl group, and the like. The group is particularly preferred.

A norbornene-based polymer having such a repeating unit is preferable because it has a very high refractive index.

Further, the norbornene-based polymer preferably contains an alkylnorbornene repeating unit. Since a norbornene-based polymer containing a repeating unit of alkylnorbornene has high flexibility, high flexibility (flexibility) can be imparted to the optical waveguide 9 by using such norbornene-based polymer.

Examples of the alkyl group that the alkylnorbornene repeating unit has include a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, and a decyl group, and a hexyl group is particularly preferable. These alkyl groups may be either linear or branched.

By including the repeating unit of hexyl norbornene, it is possible to prevent the refractive index of the entire norbornene-based polymer from being lowered and to maintain high flexibility.

Here, for example, the optical waveguide 9 is preferably used in data communication using light in a wavelength region of about 600 to 1550 nm. However, the norbornene-based polymer including a repeating unit of hexyl (alkyl) norbornene is as described above. It is preferable because it has excellent transmittance for light in a large wavelength region (particularly, a wavelength region near 850 nm).

Preferred examples of such norbornene polymers include hexyl norbornene homopolymer, phenylethyl norbornene homopolymer, benzyl norbornene homopolymer, hexyl norbornene and phenylethyl norbornene copolymer, and hexyl norbornene and benzyl norbornene copolymer. However, it is not limited to these.

The core layer forming material 900 of this embodiment includes a monomer, a promoter (first substance), and a catalyst precursor (second substance) as the additive 920.

The monomer reacts in the active radiation irradiated region by irradiation with actinic radiation, which will be described later, and forms a reaction product. It is a compound that can cause a rate difference.

Here, as this reaction product, a polymer (polymer) formed by polymerizing a monomer in a polymer (matrix) 915, a crosslinked structure that cross-links the polymers 915, and a polymer 915 that is polymerized from the polymer 915 Examples thereof include at least one of branched structures (branch polymer and side chain (pendant group)).

Here, in the layer 910, when it is desired that the refractive index of the irradiated region is high, a polymer 915 having a relatively low refractive index and a monomer having a high refractive index with respect to the polymer 915 are combined. When used and it is desired that the refractive index of the irradiated region be low, a polymer 915 having a relatively high refractive index and a monomer having a low refractive index for this polymer 915 are used in combination.

Note that “high” or “low” in the refractive index does not mean the absolute value of the refractive index but means a relative relationship between certain materials.

When the refractive index of the irradiated region in the layer 910 decreases due to the reaction of the monomer (reactant generation), the portion becomes the cladding portion 95, and the refractive index of the irradiated region increases.
This portion becomes the core portion 94.

Such a monomer is not particularly limited as long as it is a compound having a polymerizable site, and examples thereof include norbornene monomers, acrylic acid (methacrylic acid) monomers, epoxy monomers, styrene monomers, and the like. , One or two of these
A combination of more than one species can be used.

Among these, it is preferable to use a norbornene-based monomer as the monomer.
By using the norbornene-based monomer, the core layer 93 (optical waveguide 9) having excellent optical transmission performance and excellent heat resistance and flexibility can be obtained.

Here, the norbornene-based monomer is a generic term for monomers containing at least one norbornene skeleton represented by the following chemical formula 2 (structural formula A), and examples thereof include compounds represented by the following chemical formula 3 (structural formula C). .

Examples of the unsubstituted hydrocarbon group (hydrocarbyl group) include, for example, a linear or branched alkyl group having 1 to 10 carbon atoms (C _{1 to} C ₁₀ ), a linear or branched carbon number of 2 -10 (
Alkenyl C ₂ -C _10, linear or alkynyl group branched C 2~10 _(C 2 ~C _10), a cycloalkyl group having 4 to 12 carbon atoms _(C 4 ~C _12), carbon Number 4-12 (
C ₄ cycloalkenyl group -C _12), aryl group having 6 to 12 carbon atoms _(C 6 _{~C 12),}
An aralkyl group (arylalkyl group) having ₇ to ₂₄ carbon atoms (C7 to C24), and the like.
In addition, R ¹ and R ² , R ³ and R ⁴ each have ₁ to ₁₀ carbon atoms (C _{1 to} C ₁₀ ).
Or an alkylidenyl group.

Specific examples of the alkyl group include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, neopentyl group, hexyl group, heptyl group, octyl group. , Nonyl and decyl groups, but are not limited thereto.

Specific examples of the alkenyl group include, but are not limited to, a vinyl group, an allyl group, a butenyl group, and a cyclohexenyl group.

Specific examples of the alkynyl group include ethynyl group, 1-propynyl group, 2-propynyl group,
Examples include, but are not limited to, 1-butynyl group and 2-butynyl group.

Specific examples of the cycloalkyl group include, but are not limited to, a cyclopentyl group, a cyclohexyl group, and a cyclooctyl group.

Specific examples of the aryl group include a phenyl group, a naphthyl group, and an anthracenyl (ant
hracenyl) group, but is not limited thereto.

Specific examples of the aralkyl group include, but are not limited to, a benzyl group and a phenylethyl (phenethyl) group.

Further, specific examples of the alkylidenyl group include, but are not limited to, a methylidenyl group and an ethylidenyl group.

Examples of the substituted hydrocarbon group include those in which part or all of the hydrogen atoms of the hydrocarbon group are substituted with halogen atoms, that is, halohydrocarbyl (halohydrr).
ocarbyl) group, perhalohydrocarbyl (perhalohydrocarbyl)
1) or a halogenated hydrocarbon group such as a perhalocarbyl group.

In these halogenated hydrocarbon groups, as a halogen atom substituted for a hydrogen atom,
At least one selected from a chlorine atom, fluorine and bromine is preferable, and a fluorine atom is more preferable.

Among these, specific examples of the perhalogenated hydrocarbon group (perhalohydrocarbyl group, perhalocarbyl group) include, for example, a perfluorophenyl group, a perfluoromethyl group (trifluoromethyl group), and a perfluoroethyl group. Perfluoropropyl group, perfluorobutyl group, perfluorohexyl group and the like.

As the halogenated alkyl group, those having 11 to 20 carbon atoms can be suitably used in addition to those having 1 to 10 carbon atoms. That is, as the halogenated alkyl group, a group that is partially or completely halogenated, linear or branched, and represented by the general formula: —C _Z X ″ _{2Z + 1} can be selected. Here, X '' represents a halogen atom or a hydrogen atom each independently, and Z represents the integer of 1-20.

In addition to the halogen atom, the substituted hydrocarbon group may be a linear or branched alkyl group having 1 to 5 carbon atoms (C _{1 to} C ₅ ), a haloalkyl group, an aryl group, and a cycloalkyl group. Examples thereof include a substituted cycloalkyl group, aryl group and aralkyl group (aralkyl group).

Moreover, as a functional substituent, for example, — (CH ₂ ) _n —CH (CF ₂ ) ₂ —O—Si (
Me) ₃ , — (CH ₂ ) _n —CH (CF ₃ ) ₂ —O—CH ₂ —O—CH ₃ , — (CH ₂ )
_{n -CH (CF 3) 2 -O} -C (O) -O-C (CH 3) 3, - (CH 2) n -C (CF
_{3) 2 -OH, - (CH} 2) n -C (O) -NH 2, - (CH 2) n -C (O) -Cl,
^{_{- (CH 2) n -C (}} O) -O-R 5, - (CH 2) n-O-R 5, - (CH 2) n -O
—C (O) —R ⁵ , — (CH ₂ ) _n —C (O) —R ⁵ , — (CH ₂ ) _n —O—C (O) —
OR ⁵ , — (CH ₂ ) _n —Si (R ⁵ ) ₃ , — (CH ₂ ) _n —Si (OR ⁵ ) ₃ , — (C
H ₂ ) _n —O—Si (R ⁵ ) ₃ and — (CH ₂ ) _n —C (O) —OR ^{6 and the} like.

Here, in each of the formulas above, each, n is an integer of 0, ^{R 5} are each independently a hydrogen atom, a linear or branched C 1 to 20 _(C 1 -C ₂₀₎ alkyl group, a linear or branched halogenated or perhalogenated alkyl group having a carbon number 1 to 20 _(C 1 _{-C 20)} linear or branched C 2 to 10 _(C 2 ~ C ₁₀ ) alkenyl group, linear or branched C 2-10 (C ₂ -C ₁₀ ) alkynyl group, C 5
-12 (C ₅ -C ₁₂ ) cycloalkyl group, C 6-14 (C ₆ -C ₁₄ ) aryl group, C 6-14 (C ₆ -C ₁₄ ) halogenated or perhalogenated aryl Represents a group or an aralkyl group having ₇ to ₂₄ carbon atoms (C7 to C24).

Incidentally, the hydrocarbon group represented by R ⁵ represents the same hydrocarbon groups as those represented by R ¹ to R ^4. As represented by R ^{1 to} R ⁴ , the hydrocarbon group represented by R ⁵ may be halogenated or perhalogenated.

For example, when R ⁵ is a halogenated or perhalogenated alkyl group having 1 to 20 carbon atoms (C _{1 to} C ₂₀ ), R ⁵ is represented by the general formula: —C _Z X ″ _{2Z + 1} . Here, z and X ″ are the same as defined above, and at least one of X ″ is a halogen atom (for example, a bromine atom, a chlorine atom, or a fluorine atom).

Here, the perhalogenated alkyl group is a group in which all X ″ are halogen atoms in the above general formula, and specific examples thereof include a trifluoromethyl group, a trichloromethyl group, —C ₇ F _15. Although _-C 11 _{F 23} are exemplified, but not limited to.

Specific examples of the perhalogenated aryl group include, but are not limited to, a pentachlorophenyl group and a pentafluorophenyl group.

Examples of R ⁶ include —C (CH ₃ ) ₃ , —Si (CH ₃ ) ₃ , —CH (R ^7).
) —O—CH ₂ CH ₃ , —CH (R ⁷ ) OC (CH ₃ ) _3, and the cyclic group of the following chemical formula 4 and the like.

ここで、Ｒ^７は、水素原子、あるいは直鎖状または分岐状の炭素数１〜５（Ｃ_１〜Ｃ_５
）のアルキル基を表す。

Here, R ⁷ is a hydrogen atom or a linear or branched carbon number of 1 to 5 (C _{1 to} C _5.
) Represents an alkyl group.

Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an i-propyl group, a butyl group,
Examples include i-butyl group, t-butyl group, pentyl group, t-pentyl group, and neopentyl group.

In the cyclic group represented by Chemical Formula 4, an ester bond is formed between the single bond extending from the ring structure and the acid substituent.

Specific examples of R ⁶ include, for example, 1-methyl-1-cyclohexyl group, isobornyl (
isobornyl) group, 2-methyl-2-isobornyl group, 2-methyl-2-adamantyl group, tetrahydrofuranyl group, tetrahydropyranoyl group, 3-oxocyclohexanoyl group, Mevalon lactonyl (meval
onic lactylyl) group, 1-ethoxyethyl group, 1-t-butoxyethyl group and the like.

Further, as other R ⁶ , for example, a dicyclopropylmethyl group (D
cpm), dimethylcyclopropylmethyl group (Dmcp) and the like.

Moreover, it can replace with said monomer for a monomer, or can also use a crosslinkable monomer (crosslinking agent) with said monomer. This crosslinkable monomer is a compound capable of causing a crosslinking reaction in the presence of a catalyst precursor described later.

The use of the crosslinkable monomer has the following advantages. That is, since the crosslinkable monomer is polymerized faster, the time required for the formation (process) of the core layer 93 (optical waveguide 9) can be shortened. Moreover, since the crosslinkable monomer is difficult to evaporate even when heated, an increase in vapor pressure can be suppressed. Furthermore, since the crosslinkable monomer is excellent in heat resistance, the heat resistance of the core layer 93 can be improved.

Among these, the crosslinkable norbornene-based monomer is a compound including a norbornene-based moiety (norbornene-based double bond) represented by Formula 2 (Structural Formula A).

Examples of the crosslinkable norbornene-based monomer include a continuous polycyclic ring system (fused multiplexity).
clic ring systems and linked polycyclic ring systems (linked mu)
ticlic ring systems).

Examples of the continuous polycyclic ring-based compound (continuous polycyclic ring-based crosslinkable norbornene-based monomer) include compounds represented by the following chemical formula (6).

For simplicity, norbornadiene is considered to be included in a continuous polycyclic ring system and includes a polymerizable norbornene double bond.

Specific examples of this continuous polycyclic compound include, but are not limited to, compounds represented by the following chemical formula (7).

On the other hand, examples of the linked polycyclic ring-based compound (linked polycyclic ring-based crosslinkable norbornene-based monomer) include compounds represented by the following chemical formula (8).

Here, the divalent substituent refers to a group having two bonds that can be bonded to the norbornene structure at the end.

Specific examples of the divalent hydrocarbon group (hydrocarbyl group) include those represented by the general formula:-(C _d H _2d
)-, And an alkylene group (d preferably represents an integer of 1 to 10) and a divalent aromatic group (aryl group).

The divalent alkylene group, a linear or branched C 1~10 _(C 1 ~C ₁₀₎
The alkylene group is preferably methylene group, ethylene group, propylene group, butylene group, pentylene group, hexylene group, heptylene group, octylene group, nonylene group or decylene group.

The branched alkylene group is one in which a main chain hydrogen atom is substituted with a linear or branched alkyl group.

On the other hand, the divalent aromatic group is preferably a divalent phenyl group or a divalent naphthyl group.
The divalent ether group is a group represented by —R ¹⁰ —O—R ¹⁰ —.
Here, R ¹⁰ independently represents the same as R ⁹ .

Specific examples of this linked polycyclic ring compound include compounds represented by the following chemical formula 9, chemical formula 10, chemical formula 11, chemical formula 12, chemical formula 13, and fluorine-containing compounds represented by chemical formulas 14 and 15 ( Fluorine-containing crosslinkable norbornene-based monomer), but is not limited thereto.

The compound represented by the formula 10 is dimethylbis [bicyclo [2.2.1] hept-2-
Ene-5-methoxy] silane, also called dimethylbis (norbornenemethoxy) silane (abbreviated “SiX”).

Among various crosslinkable norbornene monomers, dimethylbis (norbornenemethoxy) silane (SiX) is particularly preferable. SiX has a sufficiently low refractive index with respect to a norbornene-based polymer containing a repeating unit of alkylnorbornene and / or a repeating unit of aralkylnorbornene. For this reason, the refractive index of the irradiation region irradiated with actinic radiation, which will be described later, can be reliably lowered to form the clad portion 95. Further, the refractive index difference between the core portion 94 and the clad portion 95 can be increased, and the core layer 93 (optical waveguide 9).
The characteristics (optical transmission performance) can be improved.

In addition, you may make it use the above monomers individually or in arbitrary combinations.

The catalyst precursor (second substance) is a substance capable of initiating the above-described monomer reaction (polymerization reaction, crosslinking reaction, etc.), and is a promoter (first substance) activated by irradiation with actinic radiation described later.
It is a substance whose activation temperature changes by the action of.

As the catalyst precursor (procatalyst), any compound may be used as long as the activation temperature changes (increases or decreases) with irradiation of actinic radiation. Those whose activation temperature decreases with irradiation are preferred. As a result, the core layer 93 (optical waveguide 9) can be formed by heat treatment at a relatively low temperature, and unnecessary heat is applied to the other layers, so that the characteristics (optical transmission performance) of the optical waveguide 9 are degraded. Can be prevented.

As such a catalyst precursor, a catalyst precursor containing (mainly) at least one of the compounds represented by the following formulas (Ia) and (Ib) is preferably used.

Typical catalyst precursors according to Formula Ia include Pd (OAc) ₂ (P (i-Pr) ₃ ) ₂
, Pd (OAc) ₂ (P (Cy) ₃ ) ₂ , Pd (O ₂ CCMe ₃ ) ₂ (P (Cy) ₃ ) ₂
, Pd (OAc) ₂ (P (Cp) ₃ ) ₂ , Pd (O ₂ CCF ₃ ) ₂ (P (Cy) ₃ ) ₂ ,
Pd (O ₂ CC ₆ H ₅ ) ₃ (P (Cy) ₃ ) ₂ may be mentioned, but is not limited thereto. Here, Cp represents a cyclopentyl group, and Cy
Represents a cyclohexyl group.

The catalyst precursor represented by the formula Ib is preferably a compound in which p and r are each selected from integers of 1 and 2.

Typical catalyst precursors according to such formula Ib include Pd (OAc) ₂ (P (Cy)
₃ ) ₂ is mentioned. Here, Cy represents a cyclohexyl group, and Ac represents an acetyl group.

These catalyst precursors can efficiently react with a monomer (in the case of a norbornene-based monomer, an efficient polymerization reaction, a crosslinking reaction, etc. by an addition polymerization reaction).

In the state where the activation temperature is lowered (active latent state), the catalyst precursor has an activation temperature lower by about 10 to 80 ° C. (preferably about 10 to 50 ° C.) than the original activation temperature. Is preferred. Thereby, the refractive index difference between the core part 94 and the clad part 95 can be produced reliably.

Such catalyst precursors include Pd (OAc) ₂ (P (i-Pr) ₃ ) ₂ and Pd (O
Ac) ₂ (P (Cy) ₃ ) ₂ containing (mainly) at least one of them is preferred.

Hereinafter, Pd (OAc) ₂ (P (i-Pr) ₃ ) ₂ may be abbreviated as “Pd545”, and Pd (OAc) ₂ (P (Cy) ₃ ) ₂ may be abbreviated as “Pd785”. .

The cocatalyst (first substance) is activated by irradiation with actinic radiation, and the catalyst precursor (
It is a substance that can change the activation temperature of the procatalyst (the temperature at which the monomer reacts).

As the cocatalyst (cocatalyst), any compound can be used as long as it has a molecular structure that changes (reacts or decomposes) when activated by irradiation with actinic radiation. Weakly coordinating anions (WCA) that can be decomposed by irradiation with actinic radiation and replaced with cations such as protons and other cations and leaving groups of catalyst precursors
And (mainly) those containing a compound (photoinitiator) that generates

Examples of the weak coordination anion include tetrakis (pentafluorophenyl) borate ion (FABA ⁻ ), hexafluoroantimonate ion (SbF ₆ ⁻ ), and the like.

Examples of the cocatalyst (photoacid generator or photobase generator) include tetrakis (pentafluorophenyl) borate and hexafluoroantimonate represented by the following chemical formula 17, tetrakis (pentafluorophenyl) Examples include gallates, aluminates, antimonates, other borates, gallates, carboranes, halocarboranes, and the like.

Commercially available products of such promoters include, for example, Rho, Cranberry, New Jersey.
“RHODORSIL (registered trademark, the same shall apply hereinafter) available from DIA USA.
PHOTOINITIATOR 2074 (CAS number 178233-72-2)
"TAG-372R ((dimethyl (2- (2-naphthyl) -2-oxoethyl) sulfonium tetrakis (pentafluorophenyl) borate: CAS No. 193957) available from Toyo Ink Manufacturing Co., Ltd., Tokyo, Japan" -54-9)), "MPI-103 (CAS No. 87709-41-9) available from Midori Chemical Co., Tokyo, Japan.
No.), “TAG-371 (CAS) available from Toyo Ink Manufacturing Co., Ltd., Tokyo, Japan
No. 193957-53-8), “TTBPS-TPFPB (tris (4-tert-butylphenyl) sulfonium tetrakis (pentapentafluorophenyl) borate) available from Toyo Gosei Co., Ltd., Tokyo, Japan” "NAI-105 (CAS No. 85342-62-7)" available from Midori Chemical Industries, Tokyo, Japan
Etc.

In addition, as a co-catalyst (first substance), RHODORSIL PHOTOINITIAT
When OR 2074 is used, ultraviolet rays (UV light) are preferably used as actinic radiation (chemical rays) described later, and mercury lamps (high pressure mercury lamps) are suitably used as ultraviolet irradiation means. Thereby, ultraviolet rays (active radiation) having sufficient energy of less than 300 nm can be supplied to the layer 910, and RHODORSIL PHOTOINITIAT
OR 2074 can be efficiently decomposed to generate the above cations and WCA.

Moreover, you may make it add a sensitizer in the core layer forming material (varnish) 900 as needed.

The sensitizer increases the sensitivity of the cocatalyst to actinic radiation, reduces the time and energy required for the activation (reaction or decomposition) of the cocatalyst, and the wavelength of the actinic radiation to a wavelength suitable for the activation of the cocatalyst. It has a function of changing the wavelength.

Such a sensitizer is appropriately selected depending on the sensitivity of the promoter 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, fluoranes (fluoran)
thenes), rubrenes, pyrenes, indanthrines, thioxanthen-9-ones, etc., and these may be used alone or as a mixture.

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

9,10-dibutoxyanthracene (DBA) can be obtained from Kawasaki Kasei Kogyo Co., Ltd., Kanagawa, Japan.

The content of the sensitizer in the core layer forming material 900 is not particularly limited, but is 0.01% by weight.
It is preferably at least 0.5% by weight, more preferably at least 1% by weight. In addition, it is preferable that an upper limit is 5 weight% or less.

Furthermore, an antioxidant can be added to the core layer forming material 900. Thereby, generation | occurrence | production of an undesired free radical and the natural oxidation of the polymer 915 can be prevented. As a result, the characteristics of the obtained core layer 93 (optical waveguide 9) can be improved.

This antioxidant includes Ciba Specialt in Tarrytown, New York.
y Ciba available from Chemicals (registered trademark, the same shall apply hereinafter) I
RGANOX (registered trademark, the same shall apply hereinafter) 1076 and Ciba IRGAFO
S (registered trademark, the same shall apply hereinafter) 168 is preferably used.

Other antioxidants include, for example, Ciba Irganox (registered trademark, the same shall apply hereinafter) 129, Ciba Irganox 1330, Ciba Irgan.
ox 1010, Ciba Cyanox (registered trademark, the same shall apply hereinafter) 1790,
Ciba Irganox® 3114, Ciba Irganox 312
5 etc. can also be used.

Note that such an antioxidant can be omitted, for example, when the layer 910 is not exposed to oxidation conditions or when the exposure period is extremely short.

Examples of the solvent used for preparing the core layer forming material (varnish) 900 include diethyl ether, diisopropyl ether, 1,2-dimethoxyethane (DME), 1,4-dioxane, tetrahydrofuran (THF), tetrahydropyran (THP). ), Anisole,
Ether solvents such as diethylene glycol dimethyl ether (diglyme) and diethylene glycol ethyl ether (carbitol), cellosolv solvents such as methyl cellosolve, ethyl cellosolve and phenyl cellosolve, aliphatic hydrocarbon solvents such as hexane, pentane, heptane and cyclohexane, toluene Aromatic hydrocarbon solvents such as xylene, benzene and mesitylene, aromatic heterocyclic solvents such as pyridine, pyrazine, furan, pyrrole, thiophene and methylpyrrolidone, N, N-dimethylformamide (DMF), N, N -Amide solvents such as dimethylacetamide (DMA), dichloromethane, chloroform, 1, 2
-Halogen compound solvents such as dichloroethane, ester solvents such as ethyl acetate, methyl acetate and ethyl formate, various organic solvents such as sulfur compound solvents such as dimethyl sulfoxide (DMSO) and sulfolane, or mixed solvents containing these. Is mentioned.

As a method for removing (desolving) the solvent from the liquid film formed on the support substrate 951, for example, natural drying, heating, leaving under reduced pressure, or blowing of an inert gas (blow) or the like is performed. Examples include forced drying.

As described above, the layer 910 that is a film-like solidified product (or cured product) of the core layer forming material 900 is formed on the support substrate 951.

At this time, the layer (dry film of PITDM) 910 has a first refractive index (RI). This first refractive index is due to the action of the polymer 915 and monomers that are uniformly dispersed (distributed) in the layer 910.

[2A] Next, a mask (masking) 935 in which an opening (window) 9351 is formed is prepared, and the layer 910 is irradiated with active radiation 930 through the mask 935 (FIG. 9-).
B).

Hereinafter, a case where a monomer having a refractive index lower than that of the polymer 915 is used as a monomer, and a catalyst precursor whose activation temperature decreases with irradiation of the active radiation 930 will be described as an example.

That is, in the example shown here, the irradiation region 925 of the active radiation 930 becomes the clad portion 95.

Therefore, in the example shown here, an opening (window) 9351 equivalent to the pattern of the clad portion 95 to be formed is formed in the mask 935. This opening 9351 forms a transmission part through which the active radiation 930 to be irradiated passes.

The mask 935 is formed in advance (separately formed) (for example, plate-shaped),
For example, the layer 910 may be formed by a vapor deposition method or a coating method.

Preferred examples of the mask 935 include a photomask made of quartz glass or a PET base material, a stencil mask, a metal thin film formed by a vapor deposition method (evaporation, sputtering, etc.), etc. Among these, it is particularly preferable to use a photomask or a stencil mask. This is because a fine pattern can be formed with high accuracy, and handling is easy, which is advantageous in improving productivity.

In FIG. 9B, an opening (window) equivalent to the pattern of the clad portion 95 to be formed.
9351 shows the one in which the mask is partially removed along the pattern of the non-irradiated region 940 of the active radiation 930. When using a photomask made of the quartz glass or the PET base material, the photomask For example, a material provided with a shielding portion for actinic radiation 930 made of a shielding material made of metal such as chromium may be used. In this mask, the part other than the shielding part is the window (transmission part).

The actinic radiation 930 to be used is not particularly limited as long as it can cause a photochemical reaction (change) to the promoter. For example, in addition to visible light, ultraviolet light, infrared light, and laser light, an electron beam or X Lines or the like can also be used.

Among these, the actinic radiation 930 is appropriately selected depending on the type of co-catalyst and the type of sensitizer when it contains a sensitizer, and is not particularly limited, but has a peak wavelength in the range of 200 to 450 nm. It is preferable to have it. Thereby, a cocatalyst can be activated comparatively easily.

Moreover, it is preferable that the irradiation amount of active radiation 930 is about 0.1-9 J / cm < ² >,
More preferably from 0.2~6J / cm ² or so, even more preferably about 0.2~3J / cm ^2. Thereby, a promoter can be activated reliably.

The constituent material of the mask 935 is appropriately selected according to the active radiation 930 to be irradiated. Specifically, the constituent material of the mask 935 is a material that can block the active radiation 930. Any known material may be used for the mask 935 as long as it has such characteristics.

When the layer 910 is irradiated with the active radiation 930 through the mask 935, the active radiation 930 is obtained.
The cocatalyst (first substance: cocatalyst) present in the irradiation region 925 irradiated with is reacted (bonded) or decomposed by the action of the actinic radiation 930, and cations (protons or other cations). Releases (generates) weakly coordinating anions (WCA).

These cations and weakly coordinating anions cause a change (decomposition) in the molecular structure of the catalyst precursor (second substance: procatalyst) present in the irradiation region 925, and this changes the active latent state (latent potential). Active state).

Here, the catalyst precursor in the active latent state (or the latent active state) has an activation temperature lower than the original activation temperature, but there is no temperature increase, that is, at about room temperature, the irradiation region. It refers to a catalyst precursor that is in a state where a monomer reaction cannot occur within 925.

Therefore, even after irradiation with the active radiation 930, if the layer 910 is stored at, for example, about −40 ° C., the state can be maintained without causing a monomer reaction.
For this reason, the core layer 93 can be obtained by preparing a plurality of layers 910 after irradiation with the active radiation 930 and subjecting them to heat treatment at once, which is highly convenient.

In addition, when using light with high directivity like a laser beam as actinic radiation 930,
Use of the mask 935 may be omitted.

[3A] Next, the layer 910 is subjected to heat treatment (first heat treatment).
Thereby, in the irradiation region 925, the catalyst precursor in the active latent state is activated (becomes active), and monomer reaction (polymerization reaction or cross-linking reaction) occurs.

As the monomer reaction proceeds, the monomer concentration in the irradiation region 925 gradually decreases. As a result, a difference in monomer concentration occurs between the irradiated region 925 and the unirradiated region 940, and in order to eliminate this, the monomer diffuses from the unirradiated region 940 (monomer diffusion) and collects in the irradiated region 925. come.

As a result, in the irradiation region 925, the monomer and its reactant (polymer, cross-linked structure or branched structure) increase, and the structure derived from the monomer greatly affects the refractive index of the region,
It decreases to a second refractive index lower than the first refractive index. As the monomer polymer, an addition (co) polymer is mainly produced.

On the other hand, in the unirradiated region 940, the amount of monomer decreases due to the diffusion of the monomer from the region to the irradiated region 925, so that the influence of the polymer 915 greatly appears on the refractive index of the region, and the first refraction The third refractive index is higher than the refractive index.

In this way, a refractive index difference (second refractive index <third refractive index) occurs between the irradiated region 925 and the non-irradiated region 940, and the core portion 94 (non-irradiated region 940) and the cladding portion 95. (Irradiation region 925) is formed (see FIG. 9-C).

Although the heating temperature in this heat processing is not specifically limited, It is preferable that it is about 30-80 degreeC, and it is more preferable that it is about 40-60 degreeC.

The heating time is preferably set so that the reaction of the monomer in the irradiation region 925 is almost completed. Specifically, the heating time is preferably about 0.1 to 2 hours,
More preferably, it is about the time.

Here, the core portion 94 is formed in a square shape such as a square or a rectangle (rectangle) as shown in the figure, but the width and the height thereof are preferably 1 to 20, respectively.
It is about 0 μm, more preferably about 5 to 100 μm, and still more preferably about 10 to 60 μm.

[4A] Next, the layer 910 is subjected to a second heat treatment.
As a result, the catalyst precursor remaining in the unirradiated region 940 and / or the irradiated region 925 is activated (activated) directly or with activation of the cocatalyst, thereby causing the regions 925 and 940 to be activated. The remaining monomer is reacted.

In this way, by reacting the monomers remaining in the regions 925 and 940, the core portion 94 and the clad portion 95 obtained can be stabilized.

The heating temperature in the second heat treatment is not particularly limited as long as it can activate the catalyst precursor or the cocatalyst, but it is preferably about 70 to 100 ° C., and 80 to 9
More preferably, it is about 0 ° C.

The heating time is preferably about 0.5 to 2 hours, more preferably about 0.5 to 1 hour.

[5A] Next, the layer 910 is subjected to a third heat treatment.
Thereby, the internal stress generated in the obtained core layer 93 can be reduced, and the core portion 94 and the cladding portion 95 can be further stabilized.

The heating temperature in the third heat treatment is 20 ° C. than the heating temperature in the second heat treatment.
It is preferable to set higher than this, specifically, it is preferably about 90 to 180 ° C.,
More preferably, it is about 120-160 degreeC.

The heating time is preferably about 0.5 to 2 hours, more preferably about 0.5 to 1 hour.
The core layer 93 is obtained through the above steps.

For example, when a sufficient refractive index difference is obtained between the core portion 94 and the clad portion 95 in a state before the second heat treatment or the third heat treatment is performed, this step is performed. [5A] and the step [4A] may be omitted.

[6A] Next, the cladding layer 91 (92) is formed on the support substrate 952 (FIG. 9-D).
reference).

As a method for forming the clad layer 91 (92), a method in which a varnish containing a clad material (clad layer forming material) is applied and cured (solidified), and a method in which a curable monomer composition is applied and cured (solidified). Any method may be used.

When the clad layer 91 (92) is formed by a coating method, examples thereof include 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.
As the support substrate 952, a substrate similar to the support substrate 951 can be used.

Examples of the constituent material of the clad layer 91 (92) include cyclic resins such as acrylic resin, methacrylic resin, polycarbonate, polystyrene, epoxy resin, polyamide, polyimide, polybenzoxazole, benzocyclobutene resin, and norbornene resin. These resins can be used, and one or more of these can be used in combination (polymer alloy, polymer blend (mixture), copolymer, composite (laminate), etc.).

Of these, epoxy resins, polyimides, polybenzoxazoles, cyclic olefin resins such as benzocyclobutene resins and norbornene resins, and those containing them (mainly) in terms of particularly excellent heat resistance It is preferable to use, and particularly, those mainly composed of norbornene-based resins (norbornene-based polymers) are preferable.

Since the norbornene-based polymer is excellent in heat resistance, in the optical waveguide 9 that uses this as a constituent material of the cladding layer 91 (92), when the conductor layer is formed on the optical waveguide 9, the conductor layer is processed to form a wiring. Even when heated to mount an optical element, the cladding layer 91 (
92) can be softened and prevented from being deformed.

Further, since it has high hydrophobicity, the cladding layer 91 (9
2) can be obtained.

Norbornene-based polymers or norbornene-based monomers that are raw materials thereof are also preferable because they are relatively inexpensive and easily available.

Furthermore, when a material mainly composed of a norbornene-based polymer is used as the material of the clad layer 91 (92), the clad layers 91 and 92 and the core layer 93 are excellent in resistance to deformation such as bending, even when repeatedly bent and deformed. The delamination is difficult to occur, and the occurrence of microcracks in the clad layers 91 and 93 is also prevented. And since it becomes the same kind as the material used suitably as a constituent material of the core layer 93, the adhesiveness with the core layer 93 becomes still higher,
Delamination between the clad layer 91 (92) and the core layer 93 can be prevented. For this reason, the optical transmission performance of the optical waveguide 9 is maintained, and the optical waveguide 9 having excellent durability can be obtained.

Examples of such norbornene-based polymers include (1) addition (co) polymers of norbornene monomers obtained by addition (co) polymerization of norbornene monomers, and (2) norbornene monomers and ethylene or α-olefins. (3) addition polymers such as addition copolymers with norbornene-type monomers and non-conjugated dienes, and other monomers as required, (4) ring opening of norbornene-type monomers ( A (co) polymer, 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 ( Co) polymer hydrogenated resin,
(6) a ring-opening copolymer of a norbornene-type monomer and a non-conjugated diene or another monomer,
And a ring-opening polymer such as a polymer obtained by hydrogenating the (co) polymer, if necessary. Examples of these polymers include random copolymers, block copolymers, and alternating copolymers.

These norbornene-based polymers include, for example, ring-opening metathesis polymerization (ROMP), RO
Combination of MP and hydrogenation reaction, polymerization by radical or cation, polymerization using cationic palladium polymerization initiator, polymerization using other polymerization initiator (for example, polymerization initiator of nickel or other transition metal) Etc., and can be obtained by all known polymerization methods.

Among these, as the norbornene-based polymer, an addition (co) polymer is preferable. This is preferable because it is rich in transparency, heat resistance and flexibility.

In particular, the norbornene-based polymer 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.

By including a norbornene repeating unit having a substituent containing a polymerizable group, in the cladding layer 91 (92), the polymerizable groups of at least some of the norbornene-based polymers are crosslinked directly or via a crosslinking agent. be able to. Depending on the type of polymerizable group, the type of crosslinking agent, the type of polymer used for the core layer 93, the norbornene-based polymer and the polymer used for the core layer 93 can be cross-linked. In other words, it is preferable that at least a part of the norbornene-based polymer is crosslinked at the polymerizable group.

As a result, the strength of the clad layer 91 (92) itself, the clad layer 91 (92) and the core layer 9
3 can be further improved in adhesion.

Examples of the norbornene repeating unit containing a polymerizable group include a norbornene repeating unit having a substituent containing an epoxy group, a norbornene repeating unit having a substituent containing a (meth) acryl group, and an alkoxysilyl group. At least one of the repeating units of norbornene having a substituent to be included 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 norbornene repeating units containing such a polymeric group is used, a crosslinking density can be improved further and the said effect will become more remarkable.

On the other hand, by including a norbornene repeating unit having a substituent containing an aryl group, the aryl group has extremely high hydrophobicity, so that the dimensional change due to water absorption of the cladding layer 91 (92) can be more reliably prevented. it can. In addition, since the aryl group is excellent in fat solubility (lipophilicity) and has high affinity with the polymer used for the core layer 93 as described above, the clad layer 9
1 (92) and the core layer 93 can be more reliably prevented from delamination, and the optical waveguide 9 having higher durability can be obtained.

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 is
Since flexibility is increased, the cladding layers 91 and 92 (optical waveguide 9) have high flexibility (
Flexibility).

A norbornene-based polymer containing an alkylnorbornene repeating unit is also preferable because of its excellent transmittance for light in the wavelength region as described above (particularly in the wavelength region near 850 nm).

The norbornene-based polymer used for the clad layer 91 (92) is preferably a polymer having a relatively low refractive index. On the other hand, if the norbornene-containing polymer having a substituent containing an aryl group is included, the norbornene-based polymer generally has a refractive index. However, an increase in the refractive index can be prevented by including an alkyl norbornene repeating unit.

Therefore, as the norbornene-based polymer used for the clad layer 91 (92), those represented by the following chemical formulas 18 to 21 and chemical formula 25 are preferable.

Of the norbornene-based polymers represented by Chemical formula 18, in particular, R is 4 to 10 carbon atoms.
A compound in which a and b are each 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, etc. Is preferred.

Of the norbornene-based polymers represented by Chemical formula 19, in particular, R is 4 to 10 carbon atoms.
A compound in which a is 1, for example, butylbornene and acrylic acid 2- (
5-Norbornenyl) methyl copolymer, hexylnorbornene and acrylic acid 2- (
5-Norbornenyl) methyl copolymer, decylnorbornene and acrylic acid 2- (5
A copolymer with -norbornenyl) methyl is preferred.

Of the norbornene-based polymers represented by Chemical Formula 20, R is particularly preferably 4 to 10 carbon atoms.
A compound in which a is 1 or 2, X is a methyl group or an ethyl group, for example, a copolymer of butylbornene and norbornenylethyltrimethoxysilane, hexylnorbornene and norbornenylethyltrimethoxysilane Copolymers, copolymers of decylnorbornene and norbornenylethyltrimethoxysilane, copolymers of butylbornene and triethoxysilylnorbornene, copolymers of hexylnorbornene and triethoxysilylnorbornene, copolymers of decylnorbornene and triethoxysilylnorbornene, butylbornene and Copolymer with trimethoxysilyl norbornene, Copolymer with hexyl norbornene and trimethoxysilyl norbornene, Decyl norbornene and trimethoxysilyl Copolymer such as norbornene are preferred.

In addition, as a norbornene-type polymer represented by Chemical formula 21, for example, butylbornene,
Terpolymers of either hexyl norbornene or decyl norbornene and 2- (5-norbornenyl) methyl acrylate and either norbornenylethyltrimethoxysilane, triethoxysilylnorbornene or trimethoxysilylnorbornene, butylbornene, hexylnorbornene or Terpolymer of any of decyl norbornene, 2- (5-norbornenyl) methyl acrylate and methyl glycidyl ether norbornene, any of butyl bornene, hexyl norbornene or decyl norbornene, methyl glycidyl ether norbornene, norbornenyl ethyl trimethoxysilane Terpolymers with either triethoxysilyl norbornene or trimethoxysilyl norbornene That.

Of the norbornene-based polymers represented by Chemical Formula 25, in particular, R is 4 to 10 carbon atoms.
A compound in which X ¹ is an oxygen atom, X ² is a silicon atom, Ar is a phenyl group, R ² is a methyl group, a is 1 and c is 2, for example, butylbornene and diphenylmethylnorbornenemethoxysilane A copolymer of hexylnorbornene and diphenylmethylnorbornenemethoxysilane, a copolymer of decylnorbornene and diphenylmethylnorbornenemethoxysilane, or the like, wherein R is an alkyl group having 4 to 10 carbon atoms,
X ¹ is a methylene group, X ² is carbon atom, Ar is a phenyl group, compounds wherein R ² is a hydrogen atom, a is 0, c is 1, for example, copolymers of Buchiruborunen and phenylethyl norbornene, hexyl norbornene and phenyl ethyl A copolymer of norbornene, a copolymer of decyl norbornene and phenylethyl norbornene, and the like are preferable.

Moreover, although p / q or p / q + r should just be 20 or less, it is preferable that it is 15 or less, and about 0.1-10 is more preferable. Thereby, the effect including the repeating unit of multiple types of norbornene is exhibited.

The norbornene-based polymer as described above has a relatively low refractive index in addition to the above-described characteristics. By forming the clad layer 91 (92) using such a norbornene-based polymer as a main material, the optical waveguide 9 The optical transmission performance can be further improved.

When the norbornene-based polymer includes a norbornene repeating unit having a substituent containing a (meth) acryl group, the (meth) acryl groups can be crosslinked (polymerized) relatively easily by heating. By mixing a radical generator in the cladding layer forming material, the cross-linking reaction between (meth) acrylic groups can be promoted.

Examples of the radical generator include 2,2-dimethoxy-1,2-diphenylethane-
1-one, 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane and the like are preferably used.

In addition, when the norbornene-based polymer includes a norbornene repeating unit having a substituent containing an epoxy group or a norbornene repeating unit having a substituent containing an alkoxysilyl group, in order to directly crosslink these polymerizable groups In the clad layer forming material, the same kind of substance (photoacid generator or photobase generator) as the above-mentioned promoter is mixed, and the epoxy group or alkoxysilyl group is crosslinked by the action of this substance. Just do it.

On the other hand, in order to crosslink epoxy groups, (meth) acrylic groups, or alkoxysilyl groups via a crosslinking agent, it corresponds to each polymerizable group as a crosslinking agent in the cladding layer forming material. A compound having at least one polymerizable group may be mixed.

As the crosslinking agent having an epoxy group, for example, 3-glycidoxypropyltrimethoxysilane (γ-GPS), silicone epoxy resin, and the like are preferably used.

As a crosslinking agent having a (meth) acryl group, for example, 3-methacryloxypropyltrimethoxysilane tricyclo [5.2.1.0 ^2,6 ] decane dimethanol diacrylate, tripropylene glycol diacrylate and the like are preferable. Used for.

As the crosslinking agent having an alkoxysilyl group, for example, a silane coupling agent such as 3-glycidoxypropyltrimethoxysilane or 3-aminopropyltrimethoxysilane is preferably used.

The crosslinking reaction between these polymerizable groups may be performed at the final stage of this step [6A], or may be performed after obtaining the optical waveguide 9 in the next step [7A].

Further, various additives may be added (mixed) to the cladding layer forming material.

For example, the monomer, the catalyst precursor, and the co-catalyst mentioned in the material for forming the core layer may be mixed in the material for forming the cladding layer. Thereby, in the clad layer 91 (92), the refractive index of the clad layer 91 (92) can be changed by reacting the monomer in the same manner as described above.

In particular, when a monomer containing a crosslinkable monomer is used as the monomer, the cladding layer 91 (9
In 2), at least a part of the norbornene-based polymer can be crosslinked via a crosslinking monomer. Depending on the type of crosslinking agent, the type of polymer used for the core layer 93, the norbornene-based polymer and the polymer used for the core layer 93 can be cross-linked.

In this case, since it is not required to provide a difference in refractive index in the clad layer 91 (92), it is possible to omit the promoter and use a catalyst precursor that is easily activated by heating.

Examples of such a catalyst precursor include [Pd (PCy ₃ ) ₂ (O ₂ CCH ₃ ) (NCC).
H ₃ )] tetrakis (pentafluorophenyl) borate, [2-methylally
Pd (PCy3) 2] tetrakis (pentafluorophenyl) borate, [Pd (PCy
3) 2H (NCCH3)] tetrakis (pentafluorophenyl) borate, [Pd (P
(IPr) 3) 2 (OCOCH3) (NCCH3)] tetrakis (pentafluorophenyl) borate and the like.

Examples of other additives include the antioxidants described above. By mixing the antioxidant, it is possible to prevent deterioration of the clad material (norbornene polymer) due to oxidation.
As described above, the clad layer 91 (92) is formed on the support substrate 952.

The average thickness of the clad layers 91 and 92 is preferably about 0.1 to 1.5 times the average thickness of the core layer 93, more preferably about 0.3 to 1.25 times, Specifically, the average thickness of the cladding layers 91 and 92 is not particularly limited, but is usually 1 to 200 μm, respectively.
Is preferably about 5 to 100 μm, more preferably about 10 to 60 μm.
More preferably, it is about. Thereby, the function as a clad layer is suitably exhibited while preventing the optical waveguide 9 from becoming unnecessarily large (pressure film).

[7A] Next, the core layer 93 is peeled from the support substrate 951, and the core layer 93 is sandwiched between the support substrate 952 on which the cladding layer 91 is formed and the support substrate 952 on which the cladding layer 92 is formed ( (See FIG. 9-E).

As shown by the arrow in FIG. 9-E, the support substrate 952 on which the cladding layer 92 is formed.
The clad layers 91 and 92 and the core layer 93 are pressure-bonded from above.
Thereby, the clad layers 91 and 92 and the core layer 93 are joined and integrated.

Further, this crimping operation is preferably performed under heating. The heating temperature is the cladding layer 91.
, 92 and the constituent material of the core layer 93, etc., but is usually preferably about 80 to 200 ° C., more preferably about 120 to 180 ° C.

Next, the support substrate 952 is peeled off and removed from the cladding layers 91 and 92, respectively. Thereby, the optical waveguide 9 is obtained.

In a preferable example of such an optical waveguide 9, in the core layer 93, the core portion 94 is configured with the first norbornene-based material as a main material, and the cladding portion 95 has a lower refractive index than the first norbornene-based material. 2 is composed mainly of a norbornene-based polymer having a refractive index lower than that of the first norbornene-based material (core portion 94 of the core layer 93). The

The first norbornene-based material and the second norbornene-based material are both
Although the same norbornene-based polymer is contained, the refractive index of the norbornene-based monomer having a different refractive index from that of the norbornene-based polymer is different.

Since the norbornene-based polymer has high transparency, the optical waveguide 9 having such a configuration can provide high optical transmission performance.

Further, with such a configuration, not only high adhesion between the core portion 94 and the cladding portion 95, but also high adhesion between the core layer 93, the cladding layer 91, and the cladding layer 92 is obtained,
Even when deformation such as bending occurs in the optical waveguide 9, peeling between the core portion 94 and the cladding portion 95,
The delamination between the core layer 93 and 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.

Further, since the norbornene-based polymer has high heat resistance and high hydrophobicity, the optical waveguide 9 having such a configuration has excellent durability.

In addition, since the optical waveguide 9 can be imparted with high heat resistance and high hydrophobicity, the conductor layer can be reliably formed by adopting various methods as described above while preventing deterioration (deterioration) of its characteristics. can do. In particular, even when the conductor layer is formed so as to overlap the core portion 94 important for light transmission, the core portion 94 can be prevented from being deteriorated or deteriorated.

Further, according to the manufacturing method as described above, the optical waveguide 9 having the core portion 94 having a desired shape and high dimensional accuracy can be obtained by a simple process and in a short time.

<Second production method>
Next, a second manufacturing method of the optical waveguide 9 will be described.

Hereinafter, the second manufacturing method will be described, but the description will focus on differences from the first manufacturing method, and description of similar matters will be omitted.

In the second manufacturing method, the composition of the core layer forming material 900 is different.
This is the same as the manufacturing method.

That is, the core layer forming material 900 used in the second production method is a release agent (substance) that is activated by irradiation with actinic radiation and the action of the release agent activated by branching from the main chain and the main chain. Thus, at least a part of the molecular structure contains a polymer 915 having a leaving group (leaving pendant group) that can leave from the main chain.
As the releasing agent, the same promoter as that mentioned in the first production method can be used.

Examples of the polymer 915 used in the second production method include those obtained by substituting the substituents of the polymer 915 exemplified in the first production method with a leaving group, and polymers 915 exemplified in the first production method. The thing which introduce | transduced the leaving group is mentioned.

The refractive index of the polymer 915 changes (increases or decreases) due to the leaving (cleavage) of the leaving group.

The leaving group may be any of those leaving by the action of a cation, anion or free radical, that is, any of an acid (cation) leaving group, a base (anion) leaving group, and a free radical leaving group. Although it is good, it is preferably a group capable of leaving by the action of a cation (proton) (acid group leaving group).

As the acid leaving group, in its molecular structure, -O- structure, -Si-aryl structure and-
Those having at least one of O-Si-structures are preferred. Such acid leaving groups are
Release relatively easily by the action of cations.

Among these, as the acid leaving group that causes a decrease in the refractive index of the polymer 915 by leaving, at least one of a -Si-diphenyl structure and a -O-Si-diphenyl structure is preferable.

In addition, as a free radical leaving group which leaves | separates by the effect | action of a free radical, the substituent etc. which have an acetophenone structure at the terminal are mentioned, for example.

The polymer 915 is preferably a norbornene polymer for the same reason as described in the first production method, and more preferably a norbornene polymer containing a repeating unit of alkyl (particularly hexyl) norbornene. preferable.

In consideration of the above, as the polymer 915 whose refractive index decreases due to the leaving group leaving, a homopolymer of diphenylmethylnorbornenemethoxysilane or a copolymer of hexylnorbornene and diphenylmethylnorbornenemethoxysilane is preferably used. .

Hereinafter, as an example, a case where the polymer 915 has a refractive index that decreases due to the removal of a leaving group (particularly, an acid leaving group) will be described.

That is, in the example shown here, the irradiation region 925 of the active radiation 930 becomes the clad portion 95.

[1B] A step similar to the step [1A] is performed.
At this time, the layer (dry film of PITDM) 910 has a first refractive index (RI). This first refractive index is due to the action of the polymer 915 that is uniformly dispersed (distributed) in the layer 910.

[2B] A step similar to the step [2A] is performed.
When the layer 910 is irradiated with the active radiation 930 through the mask 935, the active radiation 930 is obtained.
The release agent present in the irradiated region 925 irradiated with cation reacts (bonds) or decomposes by the action of the actinic radiation 930 to produce a cation (proton or other cation) and a weakly coordinating anion (WCA). Release (generate).

Then, the cation causes the leaving group itself to leave the main chain, or cleaves from the middle of the molecular structure of the leaving group (photo bleach).

As a result, in the irradiated region 925, the number of leaving groups in a complete state is decreased as compared with the unirradiated region 940, and the second refractive index is lower than the first refractive index. At this time, the refractive index of the unirradiated region 940 is maintained at the first refractive index.

In this way, a refractive index difference (second refractive index <first refractive index) occurs between the irradiated region 925 and the non-irradiated region 940, and the core portion 94 (non-irradiated region 940) and the cladding portion 95. (Irradiation region 925) is formed.

In this case, the irradiation dose of the actinic radiation 930 is preferably in the range of about 0.1~9J / cm ^2, more preferably about 0.3~6J / cm ^2, 0.6~6J / More preferably, it is about cm ² . Thereby, a release agent can be activated reliably.

[3B] Next, the layer 910 is subjected to heat treatment.
Thereby, the detachable group detached (cut) from the polymer 915 is, for example, irradiated region 9.
Or rearranged or cross-linked within the polymer 915.

Further, at this time, it is considered that a part of the leaving group remaining in the cladding part 95 (irradiation region 925) is further detached (cut).

Therefore, the refractive index difference between the core portion 94 and the cladding portion 95 can be further increased by performing such heat treatment.

Although the heating temperature in this heat processing is not specifically limited, It is preferable that it is about 70-195 degreeC, and it is more preferable that it is about 85-150 degreeC.

Further, the heating time is set so as to sufficiently remove the leaving group detached (cut) from the irradiation region 925, and is not particularly limited, but is preferably about 0.5 to 3 hours, ~
More preferably, it is about 2 hours.

For example, when a sufficient refractive index difference is obtained between the core portion 94 and the cladding portion 95 in a state before the heat treatment, this step [3B] may be omitted. .

In addition, if necessary, one or more heat treatments (for example, 150 to 200 ° C. × 1 to
A process of about 8 hours) can also be added.
The core layer 93 is obtained through the above steps.

[4B] A step similar to the step [6A] is performed.
[5B] A step similar to the step [7A] is performed.

The optical waveguide 9 is completed as described above.
In a preferred example of such an optical waveguide 9, the core layer 93 is made of a norbornene-based material as a main material, and the cladding layers 91 and 92 are made of a norbornene-based polymer having a refractive index lower than that of the core portion 94 of the core layer 93. Constructed as the main material.

The core portion 94 and the clad portion 95 are mainly composed of a norbornene-based polymer having a main chain and a main chain branched from the main chain and having a leaving group capable of leaving at least a part of the molecular structure from the main chain. The core part 94 and the clad part 95 have different refractive indexes due to the difference in the number of leaving groups bonded to the main chain.

Since the norbornene-based polymer has high transparency, the optical waveguide 9 having such a configuration can provide high optical transmission performance.

Further, with such a configuration, not only high adhesion between the core portion 94 and the cladding portion 95, but also high adhesion between the core layer 93, the cladding layer 91, and the cladding layer 92 is obtained,
Even when deformation such as bending occurs in the optical waveguide 9, peeling between the core portion 94 and the cladding portion 95,
The delamination between the core layer 93 and 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.

Further, since the norbornene-based polymer has high heat resistance and high hydrophobicity, the optical waveguide 9 having such a configuration has excellent durability.

In addition, since the optical waveguide 9 can be imparted with high heat resistance and high hydrophobicity, the conductor layer can be reliably formed by adopting various methods as described above while preventing deterioration (deterioration) of its characteristics. can do. In particular, even when the conductor layer is formed so as to overlap the core portion 94 important for light transmission, the core portion 94 can be prevented from being deteriorated or deteriorated.

Further, according to the manufacturing method as described above, the optical waveguide 9 having the core portion 94 having a desired shape and high dimensional accuracy can be obtained by a simple process and in a short time.

In particular, according to the second manufacturing method, at least actinic radiation may be used, and the core layer 93 can be formed by an extremely simple process.

<Third production method>
Next, the 3rd manufacturing method of the optical waveguide 9 is demonstrated.

Hereinafter, the third manufacturing method will be described, but the description will focus on differences from the first and second manufacturing methods, and the description of the same matters will be omitted.

In the third manufacturing method, a combination of the core layer forming materials used in the first and second manufacturing methods is used as the core layer forming material 900. Otherwise, the first or second manufacturing method is used. It is the same as the method.

That is, the core layer forming material 900 used in the third manufacturing method includes a polymer 915 having a leaving group as described above, a monomer, a promoter (first substance), a catalyst precursor (
2nd substance). The cocatalyst is the same as the release agent in the second production method, and has a function of releasing the release agent.

In such a core layer forming material 900, the refractive index difference between the core portion 94 and the clad portion 95 is more increased in the obtained core layer 93 due to the combination of the selected leaving group and the selected monomer. It becomes possible to adjust in stages.

As described above, a monomer having a refractive index lower than that of the polymer 915 is used as a monomer, and a catalyst precursor whose activation temperature is reduced with irradiation of the active radiation 930 is used as a polymer 915. If a material whose refractive index is lowered by the removal of the leaving group is used, the irradiation region 925 can be used as the cladding portion 95, and the core layer 93 having a very large refractive index difference from the core portion 94 can be obtained.

Hereinafter, a case where such a combination of the polymer 915, the monomer, and the catalyst precursor is used will be described as an example.

That is, in the example shown here, the irradiation region 925 of the active radiation 930 becomes the clad portion 95.

[1C] A step similar to the step [1A] is performed.
At this time, the layer (dry film of PITDM) 910 has a first refractive index (RI). This first refractive index is due to the action of the polymer 915 and monomers that are uniformly dispersed (distributed) in the layer 910.

[2C] A step similar to the step [2A] is performed.
When the layer 910 is irradiated with the active radiation 930 through the mask 935, the active radiation 930 is obtained.
The co-catalyst (first substance: cocatalyst) present in the irradiation region 925 irradiated with is reacted or decomposed by the action of the actinic radiation 930 and becomes weakly coordinated with a cation (proton or other cation). Releases (generates) anions (WCA).

These cations and weakly coordinating anions cause a change (decomposition) in the molecular structure of the catalyst precursor (second substance: procatalyst) present in the irradiation region 925, and this changes the active latent state (latent potential). Active state).

In addition, the cation causes the leaving group itself to leave the main chain, or cleaves from the middle of the molecular structure of the leaving group.

As a result, in the irradiated region 925, the number of leaving groups in a complete state is reduced as compared with the non-irradiated region 940, and the refractive index is lowered to be lower than the first refractive index. At this time, the unirradiated region 9
For the refractive index of 40, the first refractive index is maintained.

In this case, the irradiation dose of the actinic radiation 930 is preferably in the range of about 0.1~9J / cm ^2, more preferably about 0.2~5J / cm ^2, 0.2~4J / More preferably, it is about cm ² . Thereby, a promoter can be activated reliably.

[3C] The same step as the above step [3A] is performed.
Thereby, in the irradiation region 925, the catalyst precursor in the active latent state is activated (becomes active), and monomer reaction (polymerization reaction or cross-linking reaction) occurs.

As the monomer reaction proceeds, the monomer concentration in the irradiation region 925 gradually decreases. As a result, there is a difference in monomer concentration between the irradiated region 925 and the unirradiated region 940, and in order to eliminate this, the monomer diffuses from the unirradiated region 940 and the irradiated region 92.
Coming to 5.

In addition, by this heat treatment, the leaving group detached (cut) from the polymer 915 is removed from, for example, the irradiation region 925, or rearranged or crosslinked in the polymer 915.

As a result, in the irradiated region 925, the monomer and its reactant (polymer, cross-linked structure and branched structure) increase, and the structure derived from the monomer greatly affects the refractive index of the region. The refractive index is further lowered to the second refractive index due to a decrease in the leaving (cleaved) leaving group.

On the other hand, in the unirradiated region 940, the amount of monomer decreases due to the diffusion of the monomer from the region to the irradiated region 925, so that the influence of the polymer 915 greatly appears on the refractive index of the region, and the first refraction The third refractive index is higher than the refractive index.

In this way, a refractive index difference (second refractive index <third refractive index) occurs between the irradiated region 925 and the non-irradiated region 940, and the core portion 94 (non-irradiated region 940) and the cladding portion 95. (Irradiation region 925) is formed.

[4C] A step similar to the step [4A] is performed.
[5C] A step similar to the step [5A] is performed.
[6C] The same step as the above step [6A] is performed.
[7C] The same step as the above step [7A] is performed.

The optical waveguide 9 is completed as described above.
In a preferred example of such an optical waveguide 9, the core layer 93 is branched from the main chain and the main chain,
It contains a norbornene-based polymer having a leaving group capable of leaving at least a part of the molecular structure from the main chain, and the core portion 94 and the clad portion 95 are the number of leaving groups bonded to the main chain. Are different from each other, and the content of the reaction product of the norbornene monomer having a different refractive index from that of the norbornene polymer is different from each other, and the refractive indexes thereof are different. The main material is a norbornene-based polymer having a lower refractive index than the core portion 94 of the layer 93.

Since the norbornene-based polymer has high transparency, the optical waveguide 9 having such a configuration can provide high optical transmission performance.

Further, with such a configuration, not only high adhesion between the core portion 94 and the cladding portion 95, but also high adhesion between the core layer 93, the cladding layer 91, and the cladding layer 92 is obtained,
Even when deformation such as bending occurs in the optical waveguide 9, peeling between the core portion 94 and the cladding portion 95,
The delamination between the core layer 93 and 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.

Further, since the norbornene-based polymer has high heat resistance and high hydrophobicity, the optical waveguide 9 having such a configuration has excellent durability.

In addition, since the optical waveguide 9 can be imparted with high heat resistance and high hydrophobicity, the conductor layer can be reliably formed by adopting various methods as described above while preventing deterioration (deterioration) of its characteristics. can do. In particular, even when the conductor layer is formed so as to overlap the core portion 94 important for light transmission, the core portion 94 can be prevented from being deteriorated or deteriorated.

Further, according to the manufacturing method as described above, the optical waveguide 9 having the core portion 94 having a desired shape and high dimensional accuracy can be obtained by a simple process and in a short time.

In particular, according to the third manufacturing method, the refractive index difference between the core portion 94 and the cladding portion 95 can be set in multiple stages.

<Fourth manufacturing method>
Next, the 4th manufacturing method of the optical waveguide 9 is demonstrated.

FIGS. 10A to 10E are cross-sectional views schematically showing a process example of the fourth manufacturing method of the optical waveguide.

Hereinafter, although the 4th manufacturing method is explained, it explains centering on difference with the 1st-3rd manufacturing methods, and omits the explanation about the same matter.

In the fourth manufacturing method, the core layer forming material 900 and the cladding layer forming material include the first
-The thing similar to having demonstrated by the 3rd manufacturing method can be used.

In the following description, the case where the materials described in the first manufacturing method are used as the core layer forming material will be described as a representative.

[1D] First, a clad layer forming material (first varnish) is applied onto the support substrate 1000 using the same method as described above to form the first layer 1110 (FIG. 10A). reference).

As the support substrate 1000, a substrate similar to the support substrate 951 can be used.
The average thickness of the first layer 1110 is not particularly limited, but is preferably about 5 to 200 μm, more preferably about 10 to 100 μm, and still more preferably about 15 to 65 μm.

[2D] Next, a core layer forming material (second varnish) is applied onto the first layer 1110 using the same method as described above to form the second layer 1120 (FIG. 10-B).

The core layer forming material may be applied after the first layer 1110 is almost completely dried, or may be applied before the first layer 1110 is dried.

In the latter case, the first layer 1110 and the second layer 1120 are mixed with each other at the interface between them. In this case, in the obtained optical waveguide 9, the adhesion between the clad layer 91 and the core layer 93 can be improved.

In this case, each of the first varnish and the second varnish is prepared so that the viscosity (normal temperature) is preferably about 100 to 10000 cP, more preferably about 150 to 5000 cP, and further preferably about 200 to 3500 cP. Thus, the first layer 1110 and the second layer 1120 can be prevented from being mixed more than necessary at the interface between them, and the thicknesses of the first layer 1110 and the second layer 1120 can be reduced. Nonuniformity can be prevented.

The viscosity of the second varnish is preferably higher than that of the first varnish. Accordingly, it is possible to reliably prevent the first layer 1110 and the second layer 1120 from being mixed more than necessary at the interface between them.

The average thickness of the second layer 1120 is not particularly limited, but is preferably about 5 to 200 μm, more preferably about 15 to 125 μm, and still more preferably about 25 to 100 μm.

[3D] Next, a clad layer forming material (third varnish) is applied onto the second layer 1120 using the same method as described above to form the third layer 1130 (FIG. 10-C).

The third layer 1130 can be formed in the same manner as the second layer 1120.
The average thickness of the third layer 1130 is not particularly limited, but is preferably about 5 to 200 μm, more preferably about 10 to 100 μm, and still more preferably about 15 to 65 μm.
Thereby, the laminated body 2000 is obtained.

[4D] Next, the solvent in the laminate 2000 is removed (desolvent).
Examples of the method for removing the solvent include methods such as heating, leaving under atmospheric pressure or reduced pressure, and spraying (blowing) an inert gas, etc., but a method using heating is preferred. This
It is possible to remove the solvent relatively easily and in a short time.

The heating temperature is preferably about 25 to 60 ° C, and more preferably about 30 to 45 ° C.

The heating time is preferably about 15 to 60 minutes, and more preferably about 15 to 30 minutes.

[5D] Next, a mask (masking) 935 in which an opening (window) 9351 is formed is prepared, and active radiation 930 is applied to the stacked body 2000 through the mask 935 (
(See FIG. 10-D).

When the active body 930 is irradiated with the active radiation 930 through the mask 935, the second layer 1
The cocatalyst (first substance: cocatalyst) present in the irradiation region 925 irradiated with 120 actinic radiations 930 reacts or decomposes by the action of actinic radiation 930 to form cations (protons or other cations). And weakly coordinating anions (WCA) are released (generated).

These cations and weakly coordinating anions cause a change (decomposition) in the molecular structure of the catalyst precursor (second substance: procatalyst) present in the irradiation region 925, and this changes the active latent state (latent potential). Active state).

[6D] Next, heat treatment (first heat treatment) is performed on the stacked body 2000.
Thereby, in the irradiation region 925, the catalyst precursor in the active latent state is activated (becomes active), and monomer reaction (polymerization reaction or cross-linking reaction) occurs.

As the monomer reaction proceeds, the monomer concentration in the irradiation region 925 gradually decreases. As a result, there is a difference in monomer concentration between the irradiated region 925 and the unirradiated region 940, and in order to eliminate this, the monomer diffuses from the unirradiated region 940 and the irradiated region 92.
Coming to 5.

As a result, in the irradiation region 925, the monomer and its reactant (polymer, cross-linked structure or branched structure) increase, and the structure derived from the monomer greatly affects the refractive index of the region,
It decreases to a second refractive index lower than the first refractive index.

On the other hand, in the unirradiated region 940, the amount of monomer decreases due to the diffusion of the monomer from the region to the irradiated region 925, so that the influence of the polymer 915 greatly appears on the refractive index of the region, and the first refraction The third refractive index is higher than the refractive index.

In this way, a refractive index difference (second refractive index <third refractive index) occurs between the irradiated region 925 and the non-irradiated region 940, and the core portion 94 (non-irradiated region 940) and the cladding portion 95. (Irradiation region 925) is formed (see FIG. 10-E).

[7D] Next, the stacked body 2000 is subjected to a second heat treatment.
As a result, the catalyst precursor remaining in the unirradiated region 940 and / or the irradiated region 925 is activated (activated) directly or with activation of the cocatalyst, thereby causing the regions 925 and 940 to be activated. The remaining monomer is reacted.

In this way, by reacting the monomers remaining in the regions 925 and 940, the core portion 94 and the clad portion 95 obtained can be stabilized.

[8D] Next, the stacked body 2000 is subjected to a third heat treatment.
Thereby, the internal stress generated in the obtained core layer 93 can be reduced, and the core portion 94 and the cladding portion 95 can be further stabilized.
The optical waveguide 9 is obtained through the above steps.

In such a method, the core portion 94 can be visually confirmed in the stacked body 2000 after the first heat treatment.

Further, as the first varnish and the third varnish, the same composition as that of the second varnish, that is, one containing a polymer 915, a monomer, a promoter and a catalyst precursor may be used. Accordingly, the monomer reaction causes the interface between the first layer 1110 and the third layer 1130 and the second layer 1120, and / or beyond the interface, in the first layer 1110 and the third layer 1130. And the peeling between the clad layers 91 and 92 and the core layer 93 can be prevented more reliably.

In this case, for example, I: polymer 9 of the first layer 1110 and the third layer 1130
15, the refractive index (RI) relatively lower than the refractive index of the polymer 915 of the second layer 1120.
Or II: As the monomer for the first layer 1110 and the third layer 1130, the same monomer as that for the second layer 1120 is used, but the first layer 1110 and the third layer 1130 are used. The ratio of the catalyst precursor and the monomer in the second layer 1120 may be adjusted to be lower than that of the second layer 1120.

As a result, even when the active radiation 930 is irradiated, the core layer 93 is formed in the cladding layers 91 and 92.
It is possible to prevent the formation of a region having a higher refractive index than that of the core portion 94.

When a material containing a polymer 915 having a leaving group is used as the core layer forming material (second varnish), the cladding layer forming material (first varnish, third varnish) A polymer prepared using a polymer 915 having no releasing group is used, or a polymer 915 having a releasing group is used, but a polymer containing no releasing agent may be used.

Thereby, in the first layer 1110 and the third layer 1130, it is possible to prevent the leaving group from leaving (decomposing) from the polymer 915.

In this case, a promoter that is not activated when the core layer 93 is formed may be selected. For example, a cocatalyst that does not absorb actinic radiation suitable for activating the cocatalyst contained in the second varnish or is activated by the action of heat in place of the actinic radiation may be selected.

Examples of such a co-catalyst include a non-absorbing photobase generator (PBG) and a thermal base generator (TBG).

When the single conductor portion 24 is formed in the through hole 22 as in the first and second embodiments, first, the conductor portion 3 is formed on the inner peripheral surface of the through hole 22 by the method described above. Next, the core layer forming material 900 described above is filled inside, and the core layer forming material 90 is filled as necessary.
The core layer forming material 90 is irradiated with actinic radiation and heated (depending on the composition and characteristics of 0).
The light guide 24 is formed by curing 0.

In this case, the formation of the core layer 93 of the optical waveguide 9 and the formation of the light guide path 24 may be performed separately. However, the entire formation process of the core layer 93 of the optical waveguide 9 and the formation process of the light guide path 24 may be performed. Some can be done at the same time. For example, all or part of the heating process can be performed simultaneously. Thereby, the number of manufacturing steps can be reduced, and manufacturing can be performed more easily and in a short time.

When the vertical optical waveguide 23 is formed in the through hole 22 as in the third, fourth, and fifth embodiments, first, the entire circumference or part of the inner surface of the through hole 22 (rectangular portion 224) is described above. The conductor part 3 is formed by the above-described method, and then the core layer forming material 900 is filled inside (or the circular part 222). Next, the core layer forming material 9 filled by the above-described method is used.
00, for example, actinic radiation is selectively irradiated only to a portion to be the clad portion 25, and is heated at least once as necessary (according to the composition and characteristics of the core layer forming material 900). The part 24 and the clad part 25 are formed. The irradiation method and conditions of actinic radiation, the heating method and conditions, and other matters can be the same as described above.

In this case, the formation of the core layer 93 of the optical waveguide 9 and the formation of the vertical optical waveguide 23 may be performed separately, but the formation process of the core layer 93 of the optical waveguide 9 and the formation process of the vertical optical waveguide 23 All or part of it can be performed simultaneously. For example, supply of core layer forming material 900 (
All or a part of the coating, filling) step, actinic radiation irradiation step, heating step and the like can be performed simultaneously. Thereby, the number of manufacturing steps can be reduced, and manufacturing can be performed more easily and in a short time.

In the present invention, it goes without saying that the basic structure, layer structure, shape, number, arrangement, etc. of the optical waveguide structure are not limited to those shown in the drawings.

In each of the above embodiments, the light emitting element 10 has been described as a representative example as the element. However, a configuration in which a light receiving element having a light receiving portion is mounted instead of the light emitting element 10 may be used. In this case, for example, the transmission light 18 can be guided to the light receiving unit of the light receiving element by the optical waveguide 9, the optical path conversion unit 96, and the light guide path (core unit) 24. Of course, at least one set of both the light emitting element and the light receiving element may be mounted.

The present invention has been described based on the illustrated embodiments. However, the present invention is not limited to these embodiments, and the configuration of each part can be replaced with any configuration that can exhibit the same function. In addition, an arbitrary configuration may be added.

1 Optical waveguide structure 2 Substrate 22 Through hole (through hole)
222 Circular part 224 Rectangular part 23 Vertical optical waveguide 24 Light guide path (core part)
25 Clad part 26 Lens part 3 Conductor part 4 Underfill material 51, 52, 53 Conductor layer 531, 532 Site 6 Sealing material 8 Through hole (through hole)
81 Conductor post (conductor part)
DESCRIPTION OF SYMBOLS 9 Optical waveguide 91 Clad layer 92 Clad layer 93 Core layer 94 Core part 95 Clad part 96 Optical path conversion part 961 Reflecting surface 10 Light emitting element 101 Light emitting part 103 Terminal 105 Terminal 12 Electrical element (semiconductor element)
123 terminal 125 terminal 18 transmitted light 900 core layer forming material 910 layer 915 polymer 920 additive 925 irradiated region 930 active radiation 935 mask 9351 opening 940 unirradiated region 951, 952 supporting substrate 1000 supporting substrate 1110 first layer 1120 second Layer 1130 Third layer 2000 Laminate

Claims (2)

A substrate having a rigid or flexible, is composed of a laminated structure having an optical waveguide having a core part and a cladding part the refractive indices are different, and the conductor layer, and
A through hole penetrating the substrate in the thickness direction;
A light guide provided in the through hole and optically connected to the core portion;
Wherein provided in the through hole, a waveguide structure that have a, a conductor portion electrically connected to the conductor layer,
The optical waveguide is formed by laminating a first cladding layer, a core layer including the core portion and the cladding portion, and a second cladding layer in this order,
The core layer, leaving the photoacid generator, at least a portion of the by Ri molecular structure to the action of the photoacid generator which is branched and active activatable from the main chain and the main chain may be disengaged from the main chain Forming a layer containing a polymer having a functional group and a monomer compatible with the polymer and having a refractive index lower than that of the polymer, and then selectively irradiating the active radiation to the layer , In the irradiation region irradiated with the active radiation, the photoacid generator is activated, the leaving group of the polymer is released, and the monomer in the irradiation region is irradiated with the active radiation and heated. As the reaction of the monomer proceeds, the unreacted monomer gathers from the non-irradiated region where the actinic radiation is not irradiated, resulting in a difference in refractive index between the irradiated region and the non-irradiated region. The Rukoto, the irradiated region and the cladding part state, and are not the non-irradiated region was obtained as the core portion,
Each of the first cladding layer and the second cladding layer is a non-absorbing photobase as a substance that is activated by irradiation with actinic radiation or heat and is not activated when the photoacid generator is activated. An optical waveguide structure comprising: a generator or a thermal base generator; a polymer having a leaving group; and a monomer compatible with the polymer and having a refractive index lower than that of the polymer . The optical waveguide structure according to claim 1, wherein the monomer contained in the core layer can cause a polymerization reaction or a crosslinking reaction in the polymer.

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