JP4760128B2 - Optical waveguide structure and optical waveguide substrate - Google Patents

Description

  The present invention relates to an optical waveguide structure and an optical waveguide substrate including the same.

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

However, the optical waveguide structure described in Patent Document 1 has the following problems.
1. The process of forming the optical waveguide is complicated, and the degree of freedom in designing and selecting the pattern shape of the core part constituting the optical path of the transmitted light is narrow.
2. The core pattern shape accuracy and dimensional accuracy are poor.
3. When combined with a wiring pattern, the degree of freedom in designing the wiring pattern is narrow.

JP 2004-146602 A

  SUMMARY OF THE INVENTION An object of the present invention is to provide an optical waveguide structure having an optical waveguide with a wide degree of freedom in designing a pattern shape and capable of forming a core portion (optical path) with high dimensional accuracy by a simple method. It is to provide a body and an optical waveguide substrate.

Such an object is achieved by the present invention of the following (1) to ( 62 ).
(1) An optical waveguide structure comprising: a semiconductor layer composed of a semiconductor; and an optical waveguide having a core part and a clad part having different refractive indexes, and at least a part of which is embedded in the semiconductor layer. There,
The core part is a material containing a polymer mainly composed of a norbornene-based polymer and a monomer mainly composed of a norbornene-based monomer that is compatible with the polymer and has a refractive index different from that of the polymer. It is formed in a desired shape in the core layer obtained by selectively irradiating the active radiation to the layer composed of a material whose refractive index changes by irradiation and heating of radiation ,
Before SL core layer, followed by heat treatment to the layer, in one of the regions of the non-irradiated regions of the irradiation region or the active radiation active radiation is irradiated by reacting the monomer, the other The unreacted monomer moves from one region to the other region to cause a refractive index difference between the irradiated region and the unirradiated region, and either the irradiated region or the unirradiated region is An optical waveguide structure characterized in that a core portion is obtained and the other is obtained as the clad portion.

(2) comprising at least one of an element having a light emitting part and a terminal and an element having a light receiving part and a terminal ;
The optical waveguide structure according to (1), wherein at least a part of the element is embedded in the semiconductor layer .

( 3 ) comprising at least one electronic circuit element for driving the element or processing an output signal of the element ;
The optical waveguide structure according to ( 2 ), wherein at least a part of the electronic circuit element is embedded in the semiconductor layer .

( 4 ) comprising at least one electronic circuit element for driving the element or processing an output signal of the element;
The optical waveguide structure according to ( 2 ), wherein the electronic circuit element is mounted on one side of the semiconductor layer .

( 5 ) The optical waveguide structure according to any one of (1) to ( 4 ), further including an optical path conversion unit that bends an optical path of transmission light transmitted through the core unit.

( 6 ) The optical waveguide structure according to ( 5 ), wherein the optical path conversion unit is formed at a position overlapping the light emitting unit or the light receiving unit of the element in plan view.

( 7 ) The optical waveguide structure according to ( 5 ) or ( 6 ), wherein the optical path conversion unit has a reflecting surface that reflects at least a part of the transmission light.

( 8 ) Any of the above ( 5 ) to ( 7 ), wherein a translucent part having translucency with respect to transmission light transmitted through the core part is provided between the optical path changing part and the light emitting part or the light receiving part. An optical waveguide structure according to claim 1.

( 9 ) A light-emitting element having a light-emitting part and a terminal, a light-receiving element having a light-receiving part and a terminal, and the light-emitting part and the light-receiving part are formed so as to overlap each other in plan view, and transmitted through the core part A light-emitting unit side optical path conversion unit and a light-receiving unit side optical path conversion unit that bend the optical path of transmitted light,
The transmission light emitted from the light emitting unit is configured to be received by the light receiving unit sequentially through the light emitting unit side optical path conversion unit, the core unit, and the light receiving unit side optical path conversion unit ,
The optical waveguide structure according to ( 1 ), wherein the light emitting element and the light receiving element are embedded in the semiconductor layer .

( 10 ) The optical waveguide structure according to any one of (1) to ( 9 ), which has an insulating layer.

( 11 ) The optical waveguide structure according to any one of (1) to ( 10 ), which has a conductor layer.

( 12 ) The optical waveguide structure according to ( 11 ), wherein the optical waveguide structure includes a conductor post that is electrically connected to the conductor layer and extends in a thickness direction of the layer.

( 13 ) The optical waveguide structure according to any one of (1) to ( 12 ), wherein the semiconductor layer is mainly made of silicon.

( 14 ) The optical waveguide structure according to any one of (1) to ( 13 ), wherein the thickness of the semiconductor layer is 1 to 100 times the thickness of the optical waveguide.

( 15 ) The optical waveguide structure according to any one of (1) to ( 14 ), wherein at least a part of the optical waveguide is embedded in the semiconductor layer.

(16) The material whose refractive index changes is further a first substance activated by irradiation with the actinic radiation and a second substance capable of initiating a reaction of the monomer, and the activated first substance And a second substance whose activation temperature changes due to the action of the first substance,
The core layer activates the first substance and changes an activation temperature of the second substance in the irradiated region of the layer,
Next, by applying heat treatment to the layer, the second substance whose activation temperature has not changed or the second substance whose activation temperature has changed is activated, whichever has the lower activation temperature. The optical waveguide structure according to any one of (1) to (15), which is obtained by reacting the monomer in either the irradiated region or the non-irradiated region of the active radiation.

( 17 ) The first substance includes a compound that generates a cation and a weakly coordinating anion upon irradiation with the active radiation, and the second substance is produced by the action of the weakly coordinating anion. The optical waveguide structure according to ( 16 ), wherein the activation temperature varies.

( 18 ) The activation temperature of the second substance is lowered by the action of the activated first substance, and irradiation with the actinic radiation is caused by heating at a temperature higher than the temperature of the heat treatment. The optical waveguide structure according to ( 16 ) or (17 ), wherein the optical waveguide structure is activated without any loss.

( 19 ) The optical waveguide structure according to ( 18 ), wherein the second substance includes a compound represented by the following formula Ia.
(E (R) ₃ ) ₂ Pd (Q) ₂ ... (Ia)
[Wherein E (R) ₃ represents a neutral electron donor ligand of Group 15; E represents an element selected from Group 15 of the periodic table; and R represents a hydrogen atom (or One of its isotopes) or a moiety containing a hydrocarbon group, Q represents an anionic ligand selected from carboxylate, thiocarboxylate and dithiocarboxylate. ]

( 20 ) The optical waveguide structure according to ( 18 ) or ( 19 ), wherein the second substance includes a compound represented by the following formula Ib.
[(E (R) ₃ ) _a Pd (Q) (LB) _b ] _p [WCA] _r (Ib)
[Wherein E (R) ₃ represents a neutral electron donor ligand of Group 15; E represents an element selected from Group 15 of the periodic table; and R represents a hydrogen atom (or One of its isotopes) or a moiety containing a hydrocarbon group, Q represents an anionic ligand selected from carboxylate, thiocarboxylate and dithiocarboxylate, LB represents a Lewis base, WCA Represents a weakly coordinating anion, a represents an integer of 1 to 3, b represents an integer of 0 to 2, the sum of a and b is 1 to 3, p and r are This represents the number that balances the charge between the palladium cation and the weakly coordinated anion. ]

( 21 ) The optical waveguide structure according to ( 20 ), wherein p and r are each selected from an integer of 1 or 2.

( 22 ) The said core layer is obtained by heat-processing the said layer at the 2nd temperature higher than the temperature of the said heat processing after the said heat processing of said ( 16 ) thru | or ( 21 ). The optical waveguide structure according to any one of the above.

( 23 ) The core layer is obtained by heat-treating the layer at a third temperature higher than the second temperature after the heat treatment at the second temperature ( 22) ).

( 24 ) The optical waveguide structure according to ( 23 ), wherein the third temperature is 20 ° C. or more higher than the second temperature.

( 25 ) The optical waveguide structure according to any one of ( 16 ) to ( 24 ), wherein the monomer includes a crosslinkable monomer.

(26) the monomer, in the pre-Symbol crosslinking monomer, the optical waveguide structure according to dimethyl bis above is intended to include (norbornene methoxy) silane (25).

( 27 ) The polymer has a leaving group capable of leaving at least a part of the molecular structure from the main chain by the action of the activated first substance, and selectively selects the active radiation for the layer. The optical waveguide structure according to any one of the above (16) to ( 26 ), wherein the leaving group of the polymer is released in the irradiated region when irradiated with.

( 28 ) The first substance includes a compound that generates a cation and a weakly coordinating anion upon irradiation with the active radiation, and the leaving group is removed by the action of the cation. The optical waveguide structure according to ( 27 ), which is a sex group.
( 29 ) The core part and the clad part are different in the number of the leaving groups bonded to the main chain and in the content of the reactant of the monomer having a refractive index different from that of the polymer. The optical waveguide structure according to ( 27 ) or ( 28 ), wherein the refractive indexes thereof are different.

( 30 ) An optical waveguide structure comprising: a semiconductor layer composed of a semiconductor; and an optical waveguide having a core portion and a cladding portion having different refractive indexes and at least a part of which is embedded in the semiconductor layer. And
The core part is a substance that is activated by irradiation with actinic radiation, a main chain, a branch from the main chain, and a release from which at least part of the molecular structure can be detached from the main chain by the action of the activated substance A core layer obtained by selectively irradiating the active radiation to a layer composed of a material having a refractive index that changes by irradiation with active radiation . In the desired shape,
The core layer is, by selectively irradiating the actinic radiation for the previous SL layer, the irradiation area irradiated with the active radiation, to activate the material, leaving the cleavable groups of the polymer Then, by causing a refractive index difference between the irradiation region and the non-irradiation region of the active radiation, one of the irradiation region and the non-irradiation region is the core portion, and the other is the cladding portion. Is obtained as
The leaving group has an -O-Si-diphenyl structure.

( 31 ) The optical waveguide structure according to ( 30 ), wherein the core layer is obtained by performing a heat treatment on the layer after the irradiation with the active radiation.

( 32 ) The substance includes a compound that generates a cation and a weakly coordinating anion upon irradiation with the actinic radiation, and the leaving group is an acid leaving group that is released by the action of the cation. The optical waveguide structure according to ( 30 ) or ( 31 ) above.

( 33 ) The optical waveguide structure according to any one of ( 27 ) to ( 32 ), wherein the leaving group causes a decrease in the refractive index of the polymer due to the leaving.

( 34 ) The optical waveguide structure according to any one of (16) to ( 33 ), wherein the active radiation has a peak wavelength in a range of 200 to 450 nm.

( 35 ) The optical waveguide structure according to any one of (16) to ( 34 ), wherein an irradiation amount of the active radiation is 0.1 to 9 J / cm ² .

( 36 ) The optical waveguide structure according to any one of (16) to ( 35 ), wherein the active radiation is applied to the layer through a mask.

( 37 ) The optical waveguide structure according to any one of (16) to ( 36 ), wherein the layer further includes an antioxidant.

( 38 ) The optical waveguide structure according to any one of (16) to ( 37 ), wherein the layer further includes a sensitizer.

( 39 ) The optical waveguide structure according to any one of ( 30 ) to ( 32 ), wherein the polymer is mainly a norbornene-based polymer.

( 40 ) The optical waveguide structure according to ( 39 ), wherein the norbornene-based polymer is an addition polymer.

( 41 ) The core portion is composed of a first norbornene-based material as a main material, and the clad portion is composed of a second norbornene-based material having a lower refractive index than the first norbornene-based material. The optical waveguide structure according to any one of (1) to (15) above.

( 42 ) The first norbornene-based material and the second norbornene-based material each contain a same norbornene-based polymer and have a refractive index different from that of the norbornene-based polymer. The optical waveguide structure according to the above ( 41 ), wherein the refractive indexes thereof are different due to different contents of the objects.

( 43 ) The above ( 42 ), wherein the reactant is at least one of a polymer of the norbornene-based monomer, a crosslinked structure that cross-links the norbornene-based polymers, and a branched structure branched from the norbornene-based polymer. 2. An optical waveguide structure according to 1.

( 44 ) The optical waveguide structure according to ( 42 ) or ( 43 ), wherein the norbornene-based polymer includes a repeating unit of aralkyl norbornene.

( 45 ) The optical waveguide structure according to ( 42 ) or ( 43 ), wherein the norbornene-based polymer includes a repeating unit of benzylnorbornene.

( 46 ) The optical waveguide structure according to ( 42 ) or ( 43 ), wherein the norbornene-based polymer includes a repeating unit of phenylethylnorbornene.

( 47 ) The optical waveguide structure according to ( 42 ) or ( 43 ), wherein the norbornene-based polymer includes a repeating unit of alkylnorbornene.

( 48 ) The optical waveguide structure according to ( 42 ) or ( 43 ), wherein the norbornene-based polymer contains a repeating unit of hexylnorbornene.

( 49 ) The optical waveguide structure according to any one of ( 42 ) to ( 48 ), wherein the norbornene-based polymer is an addition polymer.

( 50 ) The optical waveguide structure according to any one of (16) to ( 49 ), wherein the optical waveguide structure includes a cladding layer that is provided in contact with at least one surface of the core layer and has a refractive index lower than that of the core portion.

( 51 ) The optical waveguide structure according to ( 50 ), wherein the clad layer is configured by using a norbornene-based polymer as a main material.

( 52 ) The optical waveguide structure according to ( 51 ), wherein the norbornene-based polymer is an addition polymer.

( 53 ) The optical waveguide structure according to the above ( 51 ) or ( 52 ), wherein the norbornene-based polymer contains a repeating unit of alkyl norbornene.

( 54 ) The optical waveguide structure according to any one of ( 51 ) to ( 53 ), wherein the norbornene-based polymer includes a norbornene repeating unit having a substituent containing a polymerizable group.

( 55 ) The norbornene repeating unit having a substituent containing a polymerizable group is a norbornene repeating unit having an epoxy group-containing substituent, a norbornene repeating unit having a (meth) acryl group-containing substituent, and The optical waveguide structure according to ( 54 ), which is at least one of norbornene repeating units having a substituent containing an alkoxysilyl group.

( 56 ) The optical waveguide structure according to ( 54 ) or ( 55 ), wherein at least a part of the norbornene-based polymer is crosslinked at a polymerizable group.

( 57 ) The optical waveguide structure according to any one of ( 51 ) to ( 53 ), wherein the norbornene-based polymer includes a norbornene repeating unit having a substituent containing an aryl group.

( 58 ) The optical waveguide structure according to ( 57 ), wherein at least a part of the norbornene-based polymer is crosslinked via a crosslinking agent.

( 59 ) The optical waveguide structure according to any one of ( 51 ) to ( 58 ), wherein the average of the cladding layer is 0.1 to 1.5 times the average thickness of the core layer.

( 60 ) An optical waveguide substrate comprising at least one optical waveguide structure according to any of (16) to ( 59 ) mounted on a substrate.

( 61 ) The optical waveguide substrate according to ( 60 ), wherein the substrate has a semiconductor layer different from the semiconductor layer.
( 62 ) The optical waveguide substrate according to ( 60 ) or ( 61 ), wherein the substrate has an optical waveguide different from the optical waveguide.

  According to the present invention, the core portion can be patterned by a simple method of irradiation with active radiation (active energy ray, electron beam, X-ray, etc.), and the degree of freedom in designing the pattern shape of the core portion is wide. In addition, a core portion with 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, 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.

  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, when the conductor layer is formed, wiring to the element is easy, and wiring suitable for the element is possible regardless of the type of the element (terminal installation location), and the versatility is high. Moreover, such a wiring circuit pattern using a conductor layer has a wide degree of freedom in design (for example, a degree of freedom in selection of a terminal installation location).

  In addition, when an electronic circuit element is included, the electronic circuit element can drive the element, for example, or process an output signal of the element. A good circuit design is possible and further circuit integration is possible.

  Such an optical waveguide structure and optical waveguide substrate of the present invention have a wide range of optical circuit (optical waveguide pattern) and electrical circuit design, good yield, high optical transmission performance, reliability and durability. Excellent in versatility and versatility. Therefore, the present invention can be used for various electronic components, electronic devices, and the like.

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

  1 and 2 are cross-sectional views showing an embodiment of an optical waveguide structure of the present invention, FIG. 3 is a cross-sectional view taken along line AA in FIG. 1, and FIG. It is sectional drawing which shows embodiment of an optical waveguide board | substrate. Hereinafter, with reference to these drawings, configuration examples of the optical waveguide structure and the optical waveguide substrate will be described. In the following description, the upper side in FIGS. 1 to 4 is “upper” or “upper”, and the lower side is “lower” or “lower”. Each figure is exaggerated in the thickness direction of the layer (the 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 semiconductor layer (semiconductor substrate) 2, an optical waveguide 9, optical path conversion units 96 a and 96 b that bend the optical path of the optical waveguide 9, and the semiconductor layer 2. Conductor layer 51 bonded to the lower surface of the semiconductor layer, light emitting element 10, light receiving element 11, electronic circuit elements 12, 13, conductor layers 52 and 53 bonded to the upper surface of semiconductor layer 2, and upper surface of semiconductor layer 2 And an insulating layer 3 bonded to each other.

  The semiconductor layer 2 is made of a semiconductor material such as silicon, gallium / arsenic, indium / phosphorus, germanium, silicon carbide, silicon germanium, or the like, and particularly preferably made of silicon as a main material.

  The thickness of the semiconductor layer 2 is not particularly limited, but is preferably about 1 to 100 times the thickness of the optical waveguide 9 and more preferably about 1.5 to 80 times. As a specific example of the thickness of the semiconductor layer 2, for example, the thickness can be about 15 μm to 2 mm, and preferably about 50 μm to 1 mm.

  A predetermined circuit (semiconductor circuit) is formed in the semiconductor layer 2. Examples of this circuit include a CPU, a memory, a signal amplifier, and an element driving device. An electrical signal generated in the semiconductor circuit portion of the circuit integrated with the light receiving / emitting element is converted into an optical signal by the light emitting element 10, transmitted through the optical waveguide 9, and converted into an electrical signal by the light receiving element 11. Has advantages that it is possible to eliminate a decrease in signal transmission accuracy, a decrease in transmission speed, and a complicated mounting process, which are caused by combining separate semiconductor elements, light receiving / emitting elements, and an optical waveguide.

  An optical waveguide 9 is installed (embedded) under the semiconductor layer 2. The present invention is not limited to the case where the entire optical waveguide 9 is embedded in the semiconductor layer 2, and a configuration in which at least a part of the optical waveguide 9 is embedded in the semiconductor layer 2 may be employed.

  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 (see FIG. 3). The core portion 94 is a portion that forms an optical path of the transmission light, and the cladding portion 95 does not form an optical path of the transmission light although it is formed in the core layer 93 and performs the same function as the cladding layers 91 and 92. Part.

  In the configuration shown in FIG. 1, a core portion 94 is formed over the entire length of the core layer 93 (between reflective surfaces 961a and 961b described later).

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

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

  The core layer 93 obtained as described above is selectively irradiated with 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 the active radiation changes (the refractive index may increase or decrease depending on the material of the core layer 93), and the active radiation is not irradiated. A difference in refractive index occurs between the parts. 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. 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 difference in refractive index between the core portion 94 and the cladding portion 95 becomes larger, which is preferable. This principle will be described later in detail.

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

  A light emitting element 10, a light receiving element 11, and electronic circuit elements 12 and 13 are installed (embedded) above the semiconductor layer 2. In this case, the upper surfaces of the light emitting element 10, the light receiving element 11, and the electronic circuit elements 12 and 13 are embedded in the semiconductor layer 2 so as to coincide with the upper surface of the semiconductor layer 2.

  In the present invention, the light emitting element 10, the light receiving element 11, and the electronic circuit elements 12 and 13 are not limited to being entirely embedded in the semiconductor layer 2, but at least a part of them is in the semiconductor layer 2. It may be a configuration embedded in

  The light emitting element 10 has a light emitting portion 101 on the lower surface side in FIG. 1 and a terminal 103 on the upper surface side. In the inner part of FIG. 1 of the terminal 103, another terminal (not shown) connected to the ground is installed, and light is emitted by energizing (giving a potential difference) between the terminal 103 and the terminal 103. The unit 101 emits light.

  Note that the light emitting unit 101 in the light emitting element 10 may be composed of a single 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 in a matrix (for example, n × m: n, m And those in which a plurality of light emitting points are arranged randomly (irregularly). The same applies to a light receiving portion 111 in the light receiving element 11 described later.

  The light receiving element 11 has a light receiving portion 111 on the lower surface side in FIG. 1 and a terminal 113 on the upper surface side. Another terminal (not shown) connected to the ground is installed at the back of the terminal 113 in FIG. 1, and when the light receiving unit 111 receives light, an electrical signal is output to the terminal 113.

  The electronic circuit elements 12 and 13 are each composed of, for example, a semiconductor element (semiconductor chip). Although the function of the electronic circuit element 12 is not particularly limited, an example is one that constitutes a circuit for driving the light emitting element 10. Although the function of the electronic circuit element 13 is not particularly limited, an example is one that constitutes a circuit for processing (for example, amplifying) the output signal of the light receiving element 11.

  The electronic circuit element 12 has a terminal 123 on the upper surface side in FIG. At the back of the terminal 123 in FIG. 1, another terminal (not shown) connected to the ground is installed.

  The electronic circuit element 13 has a terminal 133 on the upper surface side in FIG. At the back of the terminal 133 in FIG. 1, another terminal (not shown) connected to the ground is installed.

  A conductor layer 51 is bonded to the lower surface of the semiconductor layer 2 (the lower surface of the optical waveguide 9). The conductor layer 51 may be patterned into a predetermined shape to form a desired wiring or circuit as in a third embodiment described later (see FIG. 4).

  Further, conductor layers 52 and 53 that are patterned into a predetermined shape and constitute a desired wiring or circuit are joined to the upper surface of the semiconductor layer 2. By the conductor layer 52, the terminal 123 of the electronic circuit element 12 and the terminal 103 of the light emitting element 10 are electrically connected. The conductor layer 53 electrically connects the terminal 133 of the electronic circuit element 13 and the terminal 113 of the light receiving element 11.

  Examples of the constituent material of the conductor layers 51, 52, and 53 include various metal materials such as copper, a copper alloy, aluminum, an aluminum alloy, gold, a gold alloy, tungsten, and a tungsten alloy. Although the thickness of the conductor layers 51-53 is not specifically limited, Usually, about 3-120 micrometers is preferable and about 5-70 micrometers 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.

  When a metal that easily diffuses into the semiconductor layer 2, such as copper, is used as the material of the conductor layers 51 to 53, a barrier layer (not shown) made of, for example, titania or tantalum is used as the semiconductor layer. It is preferable to form on the surface of 2 and to form the conductor layers 51-53 on it.

  Further, when a metal having poor adhesion to the semiconductor layer 2, such as tungsten, is used as a material for the conductor layers 51 to 53, an adhesion layer (not shown) that can improve adhesion is formed, and the adhesion layer It is preferable to form the conductor layers 51 to 53 through the conductors.

  An insulating layer 3 having electrical insulation is bonded to the upper surface of the semiconductor layer 2. The insulating layer 3 is disposed so as to cover the upper surfaces of the light emitting element 10, the light receiving element 11, the electronic circuit elements 12 and 13, and the conductor layers 52 and 53, whereby the light emitting element 10, the light receiving element 11, Electronic circuit elements 12 and 13 are sealed. That is, the light emitting element 10, the light receiving element 11, and the electronic circuit elements 12 and 13 are built in the optical waveguide structure 1.

  With such a configuration, the light emitting element 10, the light receiving element 11, and the electronic circuit elements 12 and 13 are sealed without being exposed to the outside, so that they are protected from dirt, damage, oxidative degradation, etc. Contributes to the improvement of reliability.

  As the insulating layer 3, for example, a flexible resin film (sheet material) can be used. As a constituent material of the insulating layer 3, for example, polyamide such as polyamide, polyimide, polyamideimide, polyetherimide, polyesterimide, polyethylene terephthalate, polyether ether ketone, polyethylene sulfide, polyphenylene sulfide, polyquinoline, polynorbornene, polybenzo Examples thereof include oxazole, polybenzimidazole, epoxy resin, phenol resin, bismaleimide resin, bismaleimide / triazine resin, triazole resin, polycyanurate, polyisocyanurate, and benzocyclobutene resin. These materials may be used alone or in combination. The insulating layer 3 may be a laminate in which a plurality of resin material layers having different compositions are laminated.

  The thickness of the insulating layer 3 is not particularly limited, but is preferably about 5 to 100 μm and more preferably about 10 to 80 μm in view of the insulating function and strength.

  The core portion 94 of the optical waveguide 9 has a pattern shape that overlaps with the light emitting portion 101 of the light emitting element 10 in plan view (when viewed from above in FIG. 1) (that is, passes through directly under the light emitting portion 101). Is formed. Further, the core portion 94 of the optical waveguide 9 overlaps with the light receiving portion 111 of the light receiving element 11 in a plan view (when viewed from above in FIG. 1) (that is, passes through directly below the light receiving portion 111). It is formed in a shape.

  In the core layer 93, a clad portion 95 exists before and after the core portion 94 in FIG. 1 (left and right in FIG. 3). 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 such a configuration, the core portion 94 functions as a light guide path surrounded by the clad portion on the entire outer periphery.

  Such an optical waveguide 9 includes an optical path conversion unit (light emitting unit side optical path conversion unit) 96a and an optical path conversion unit (light receiving unit side optical path conversion unit) 96b that bend the optical path of the core portion 94. In the present embodiment, optical path conversion sections 96a and 96b are formed at both ends of the core section 94 in FIG.

  Each of the optical path conversion units 96a and 96b includes reflection surfaces (mirrors) 961a and 961b that reflect at least a part of the transmitted light. The reflecting surfaces 961a and 961b are provided at a position directly below the light emitting unit 101 and a position directly below the light receiving unit 111, respectively.

  The reflecting surfaces 961a and 961b are inclined by approximately 45 ° with respect to the optical path of the optical waveguide 9, that is, the longitudinal direction of the core portion 94, and have a function of reflecting most of the transmitted light (for example, 90% or more). Yes.

  Such optical path conversion units 96a and 96b are formed by, for example, partially cutting (removing) a part (end) of the optical waveguide 9 to form an inclined surface, and using the inclined surface as the reflecting surfaces 961a and 961b. Can do. The reflection surfaces 961a and 961b may have a reflection film or a reflection enhancement film such as a multilayer optical thin film or a metal thin film (for example, an aluminum vapor deposition film). Although not shown, the inclined surface of the optical path conversion unit 96 may be filled or joined with a filler, particularly a filler having a refractive index different from that of the core 94.

  A through hole 22 is formed at a position directly below the light emitting unit 101 in the semiconductor layer 2 (between the light emitting unit 101 and the optical path conversion unit 96a), and a position directly below the light receiving unit 111 (the light receiving unit 111 and the optical path conversion). A through hole 23 is formed between the portion 96b).

  Each of the through holes 22 and 23 constitutes a light transmitting part 21 that transmits the transmitted light. That is, the through holes 22 and 23 serve as a light guide path that guides (transmits) the transmitted light in the thickness direction of the semiconductor layer 2.

  Although not shown, the transmittance of the transmitted light is 80% or more, preferably 90% or more, more preferably 95% or more in the inside (all or a part) of the through holes 22 and / or 23. The filler may be filled.

  Although not shown, a vertical optical waveguide configured by a core portion and a cladding portion surrounding the outer periphery of the core portion and transmitting light in the vertical direction is inserted in the through holes 22 and / or 23. May be.

  Further, the light transmitting portion 21 (through holes 22 and / or 23) may be provided with a lens capable of condensing or diffusing transmitted light.

  In the optical waveguide structure 1 of the present embodiment, when the electronic circuit element 12 is operated and the terminal 103 of the light emitting element 10 is energized through the terminal 123 and the conductor layer 52, the light emitting unit 101 is turned on, and FIG. Light emitted toward the middle and lower passes through the through-hole 22, passes through the cladding layer 92, is reflected by the reflecting surface 961 a, bends 90 °, enters the core portion 94 of the optical waveguide 9, and enters the cladding portion (cladding). It advances along the longitudinal direction (right direction in FIG. 1) in the core portion 94 while repeating reflection at the interfaces with the layers 91 and 92 and the side cladding portions 95). The transmitted light that has traveled through the core portion 94 is reflected by the reflecting surface 961b and bent 90 °, travels upward, passes through the cladding layer 92, passes through the through hole 23, and is received by the light receiving portion 111. The received light is photoelectrically converted and an electrical signal is output from the terminal 113. This electric signal is input to the element 13 from the terminal 133 through the conductor layer 53, and predetermined signal processing is performed.

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, the description is abbreviate | omitted about the matter similar to the said 1st Embodiment, and it demonstrates centering around difference.

  In the optical waveguide structure 1 of the present embodiment, the electronic circuit elements 12 and 13 are not installed inside the optical waveguide structure 1, and are mounted on the upper surface (one side) of the optical waveguide structure 1. The structure accompanying it is different from the above, and the rest is the same.

  That is, among the light emitting element 10, the light receiving element 11, and the electronic circuit elements 12 and 13, the light emitting element 10 and the light receiving element 11 are embedded in the upper part of the semiconductor layer 2. The insulating layer 3 is joined. Electronic circuit elements 12 and 13 are mounted on the upper side (above) of the insulating layer 3.

  On the upper surface of the insulating layer 3, conductor layers 52 and 53 which are patterned into a predetermined shape and constitute a desired wiring or circuit are joined.

  The electronic circuit element 12 has three terminals 123, 125, and 127 on the lower surface side in FIG. The terminals 125 and 127 are connected to a power source and a ground, respectively. Each of the terminals 123, 125, and 127 is connected to a predetermined portion of the conductor layer 52 via the solder 4.

  The electronic circuit element 13 has three terminals 133, 135 and 137 on the lower surface side in FIG. The terminals 135 and 137 are connected to a power source and a ground, respectively. Each of the terminals 133, 135, and 137 is connected to a predetermined portion of the conductor layer 53 via the solder 4.

  As shown in FIG. 2, the insulating layer 3 is formed with two through holes (through holes) 8 penetrating in the thickness direction. Each 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, gold, a gold-based alloy, tungsten, and a tungsten alloy), and conductor posts 81 and 82, respectively. Is forming.

  The lower end of the conductor post 81 is connected to the terminal 103 of the light emitting element 10, and the upper end of the conductor post 81 is connected to a predetermined part of the conductor layer 52. Thereby, the terminal 123 of the electronic circuit element 12 and the terminal 103 of the light emitting element 10 are electrically connected through the solder 4, the conductor layer 52, and the conductor post 81.

  The lower end of the conductor post 82 is connected to the terminal 113 of the light receiving element 11, and the upper end of the conductor post 82 is connected to a predetermined portion of the conductor layer 53. Thereby, the terminal 133 of the electronic circuit element 13 and the terminal 113 of the light receiving element 11 are electrically connected via the solder 4, the conductor layer 53, and the conductor post 82.

  Although not shown, a through hole penetrating the semiconductor layer 2 and the insulating layer is formed, and a conductor post similar to the above is inserted into the through hole, and the conductor layer 51 and the conductor layer 52 are formed by the conductor post. It can also be set as the structure which electrically connected predetermined parts or predetermined parts of the conductor layer 51 and the conductor layer 53.

  In the optical waveguide structure 1 of the present embodiment, when the electronic circuit element 12 is activated and the terminal 103 of the light emitting element 10 is energized through the terminal 123, the solder 4, the conductor layer 52, and the conductor post 81, the light emitting portion 2 is turned on and light emitted downward in FIG. 2 passes through the through-hole 22, passes through the cladding layer 92, is reflected by the reflecting surface 961 a, and bends 90 °, and the core portion 94 of the optical waveguide 9. Then, while reflecting repeatedly at the interface with the cladding part (cladding layers 91 and 92 and the side cladding part 95), it proceeds along the longitudinal direction (right direction in FIG. 2) in the core part 94. The transmitted light that has traveled through the core portion 94 is reflected by the reflecting surface 961b and bent 90 °, travels upward, passes through the cladding layer 92, passes through the through hole 23, and is received by the light receiving portion 111. The received light is photoelectrically converted and an electrical signal is output from the terminal 113. This electric signal is input to the element 13 from the terminal 133 via the conductor post 82, the conductor layer 53, and the solder 4, and is subjected to predetermined signal processing.

<Embodiment of Optical Waveguide Substrate: FIG. 4>
FIG. 4 shows an embodiment of the optical waveguide substrate of the present invention. Hereinafter, the optical waveguide substrate 6 will be described, but the description of the same matters as in the first and second embodiments will be omitted, and differences will be mainly described.

  The optical waveguide substrate 6 is obtained by mounting two optical waveguide structures 1 of the first embodiment (FIG. 1) on a substrate 7.

  The substrate 7 has substantially the same configuration as the optical waveguide structure 1 of the second embodiment (however, the electronic circuit elements 12 and 13 in the second embodiment are replaced with the optical waveguide structure 1 of the first embodiment, respectively). ing). That is, the substrate 7 includes a semiconductor layer 2 made of silicon or the like, an optical waveguide 9, optical path conversion units 96 c and 96 d that bend the optical path of the optical waveguide 9, and a conductor layer 55 bonded to the lower surface of the semiconductor layer 2. A light emitting element 10 and a light receiving element 11 embedded in the upper part of the semiconductor layer 2, a light transmitting part 21 (through holes 22 and 23) formed in the semiconductor layer 2, and an upper surface of the semiconductor layer 2. Insulating layer 3 and conductor layers 56 and 57 bonded to the upper surface of insulating layer 3 and patterned into a predetermined shape.

  The optical waveguide 9 in the substrate 7 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. 4. The core layer 93 includes a core portion 94 having a predetermined pattern and a clad. A portion 95 is formed (the cross section is the same as in FIG. 3). 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 core portion 94 is a portion that forms an optical path of the transmission light, and the cladding portion 95 does not form an optical path of the transmission light although it is formed in the core layer 93 and performs the same function as the cladding layers 91 and 92. Part.

  In the configuration shown in FIG. 4, the core portion 94 is formed in a linear shape over the entire length of the core layer 93 (between the reflecting surfaces 961c and 961d). ) Includes a clad portion 95. 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, whereby the core part 94 functions as a light guide path surrounded by the clad part on the entire outer periphery. . 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.

  Such an optical waveguide 9 has an optical path conversion section (light emitting section side optical path conversion section) 96c and an optical path conversion section (light receiving section side optical path conversion section) 96d that bend the optical path of the core section 94. In the present embodiment, optical path conversion portions 96c and 96d are formed at both ends of the core portion 94 in FIG.

  Each of the optical path conversion units 96c and 96d includes reflection surfaces (mirrors) 961c and 961d that reflect at least a part of the transmitted light. The reflective surfaces 961c and 961d are provided at a position directly below the light emitting unit 101 and a position directly below the light receiving unit 111, respectively.

  The reflecting surfaces 961c and 961d are inclined by approximately 45 ° with respect to the optical path of the optical waveguide 9, that is, the longitudinal direction of the core portion 94, and have a function of reflecting most of the transmitted light (for example, 90% or more). Yes.

  Such optical path conversion parts 96c and 96d are formed by, for example, cutting (removing) a part (end part) of the optical waveguide 9 obliquely to form an inclined surface, and using the inclined surface as the reflecting surfaces 961c and 961d. Can do. The reflecting surfaces 961c and 961d may have a reflecting film or a reflection increasing film such as a multilayer optical thin film or a metal thin film (for example, an aluminum vapor deposition film). Although not shown, the inclined surface of the optical path conversion unit 96 may be filled or joined with a filler, particularly a filler having a refractive index different from that of the core 94.

  A through hole 22 is formed at a position directly below the light emitting unit 101 in the semiconductor layer 2 (between the light emitting unit 101 and the optical path conversion unit 96c), and a position just below the light receiving unit 111 (the light receiving unit 111 and the optical path conversion). A through hole 23 is formed between the portion 96d).

  Each of the through holes 22 and 23 constitutes a light transmitting part 21 that transmits the transmitted light. That is, the through holes 22 and 23 serve as a light guide path that guides (transmits) the transmitted light in the thickness direction of the semiconductor layer 2.

  Although not shown, the transmittance of the transmitted light is 80% or more, preferably 90% or more, more preferably 95% or more in the inside (all or a part) of the through holes 22 and / or 23. The filler may be filled.

  Although not shown, a vertical optical waveguide configured by a core portion and a cladding portion surrounding the outer periphery of the core portion and transmitting light in the vertical direction is inserted in the through holes 22 and / or 23. May be.

  Further, the light transmitting portion 21 (through holes 22 and / or 23) may be provided with a lens capable of condensing or diffusing transmitted light.

  The two optical waveguide structures 1 of the first embodiment (FIG. 1) mounted on the substrate 7 each have a conductor layer 51 patterned in a predetermined shape on the lower surface thereof. On the other hand, the conductor layers 56 and 57 bonded to the upper surface of the insulating layer 3 of the substrate 7 are also patterned into a predetermined shape. Predetermined portions of the conductor layer 51 and the conductor layer 56 of one (left side in FIG. 4) of the optical waveguide structure 1 are electrically connected by the solder 4 and the other (right side in FIG. 4) of the optical waveguide structure 1 is connected. Predetermined portions of the conductor layer 51 and the conductor layer 57 are electrically connected by solder 4.

  In the insulating layer 3 of the substrate 7, two through holes (through holes) 8 penetrating in the thickness direction are formed. Each through hole 8 is filled with a conductive material (for example, various metal materials such as copper, copper-based alloy, aluminum, aluminum-based alloy, gold, gold-based alloy, tungsten, tungsten alloy, etc.), and conductor posts 83, 84, respectively. Is forming.

The lower end of the conductor post 83 is connected to the terminal 103 of the light emitting element 10, and the upper end of the conductor post 83 is connected to a predetermined part of the conductor layer 56. The lower end of the conductor post 84 is connected to the terminal 113 of the light receiving element 11, and the upper end of the conductor post 84 is connected to a predetermined part of the conductor layer 57.
With such a configuration, the conductor layer 51 of one optical waveguide structure 1 and the terminal 103 of the light emitting element 10 are electrically connected, and the conductor layer 51 of the other optical waveguide structure 1 and the terminal 113 of the light receiving element 11 are electrically connected. To do.

In addition, the board | substrate 7 is not restricted to the thing of the structure of illustration, For example, a normal resin board may be sufficient. Examples of the resin substrate include epoxy resins, phenol resins, bismaleimide resins, bismaleimide / triazine resins, triazole resins, polycyanurate resins, polyisocyanurate resins, benzocyclobutene resins, polyimides, polybenzoxazole resins, The thing comprised with various resin materials, such as norbornene resin, is mentioned.
Further, the substrate 7 may be, for example, a fiber base material (woven fabric, nonwoven fabric, woven fabric, knitted fabric, etc.) such as glass fiber or resin fiber impregnated with the resin material as described above (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 7.
Moreover, the board | substrate 7 may be a laminated body (structure other than shown in FIG. 4) 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. Furthermore, you may have arbitrary layers, such as a conductor layer, an insulating layer, and an adhesive layer. Needless to say, the layer structure of the substrate 7 is not limited to these.

  In the optical waveguide substrate 6 of the present embodiment, one (left side in FIG. 4) of the optical waveguide structure 1 operates, and the terminal 103 of the light emitting element 10 is interposed via the conductor layer 51, the solder 4, the conductor layer 56, and the conductor post 83. 4 is turned on, the light emitted downward in FIG. 4 passes through the through hole 22, passes through the cladding layer 92, is reflected by the reflecting surface 961c, and is bent by 90 °. Then, while entering the core portion 94 of the optical waveguide 9 and repeatedly reflecting at the interface with the cladding portions (cladding layers 91 and 92 and the side cladding portions 95), the inside of the core portion 94 is moved in the longitudinal direction (right in FIG. 4). Direction). The transmitted light that has traveled through the core portion 94 is reflected by the reflecting surface 961d and bent 90 °, travels upward, passes through the cladding layer 92, passes through the through hole 23, and is received by the light receiving portion 111. The received light is photoelectrically converted and an electrical signal is output from the terminal 113. This electrical signal is input to the other (right side in FIG. 4) optical waveguide structure 1 through the conductor post 84, the conductor layer 57, the solder 4, and the conductor layer 51, and predetermined signal processing is performed.

  The optical waveguide substrate 6 of this embodiment can be applied to, for example, a stacked IC, a multi CPU, a Cell, or a chip in which these are further integrated.

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

  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.

  FIG. 5-A to FIG. 5-E 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. 5-A).
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, examples thereof include a doctor blade method, a spin coating method, a dipping method, a table coating method, a spray method, an applicator method, a curtain coating method, a die coating method, and the like. It is not done.

  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 contains a light-induced heat-developable material (PITDM) composed of a polymer 915 and an additive 920 (in this embodiment, including at least a monomer, a promoter, and a catalyst precursor). It is 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 polymers 915 include cyclic olefin resins such as norbornene resins and benzocyclobutene resins, acrylic resins, methacrylic resins, polycarbonates, polystyrenes, 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.

  The norbornene polymer may be either one having a single repeating unit (homopolymer) or one having two or more norbornene repeating units (copolymer).

  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) ring-opening copolymer of norbornene type monomer and non-conjugated diene or other monomer, and (co) polymerization if necessary And a ring-opening polymer such as a polymer obtained by hydrogenating the body. Examples of these polymers include random copolymers, block copolymers, and alternating copolymers.

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

  Among these, as the norbornene-based 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, in order to obtain a polymer 915 having a relatively low refractive index, a monomer having an alkyl group, a fluorine atom or an ether structure (ether group) is generally selected in the molecular structure, and the polymer 915 is synthesized ( Polymerization).

  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.

  Examples of the aralkyl group (arylalkyl group) of the aralkylnorbornene repeating unit include benzyl group, phenylethyl group, phenylpropyl group, phenylbutyl group, naphthylethyl group, naphthylpropyl group, fluorenylethyl group, fluorene group, and the like. Examples thereof include a nylpropyl group, and a benzyl group and a phenylethyl group are particularly preferable.

  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 an alkylnorbornene repeating unit 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 reactant. Due to the presence of this reactant, the monomer refracts in the irradiated region in the layer 910 and in the non-active radiation irradiated region. 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 monomer reaction (reactant generation), the portion becomes the cladding portion 95, and when the refractive index of the irradiated region increases, the portion becomes the core portion 94. It becomes.

  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. These can be used alone or in combination of two or more.

  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). .

［式中、ａは、単結合または二重結合を表し、Ｒ^１〜Ｒ^４は、それぞれ独立して、水素原子、置換もしくは無置換の炭化水素基、または官能置換基を表し、ｍは、０〜５の整数を表す。ただし、ａが二重結合の場合、Ｒ^１およびＲ^２のいずれか一方、Ｒ^３およびＲ^４のいずれか一方は存在しない。］

[Wherein, a represents a single bond or a double bond, R ^{1 to} R ⁴ each independently represents a hydrogen atom, a substituted or unsubstituted hydrocarbon group, or a functional substituent; Represents an integer of 0 to 5; However, when a is a double bond, either one of R ¹ and R ² or one of R ³ and R ⁴ does not exist. ]

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 (C ₂ -C ₁₀ alkenyl group, linear or branched alkynyl group having 2 to 10 carbon atoms (C ₂ -C ₁₀ ), cycloalkyl having 4 to 12 carbon atoms (C ₄ -C ₁₂ ) Group, C 4-12 (C ₄ -C ₁₂ ) cycloalkenyl group, C 6-12 (C ₆ -C ₁₂ ) aryl group, C 7-24 (C ₇ -C ₂₄ ) aralkyl group In addition, R ¹ and R ² , R ³ and R ⁴ may each be an alkylidenyl group having 1 to 10 carbon atoms (C _{1 to} C ₁₀ ).

  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, but are not limited to, ethynyl group, 1-propynyl group, 2-propynyl group, 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, but are not limited to, a phenyl group, a naphthyl group, and an anthracenyl group.

  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 some or all of the hydrogen atoms of the hydrocarbon group are substituted with halogen atoms, that is, halohydrocarbyl groups, perhalohydrocarbyl groups. Or halogenated hydrocarbon groups such as perhalocarbyl groups.

  In these halogenated hydrocarbon groups, the halogen atom substituted with a hydrogen atom is preferably at least one selected from a chlorine atom, fluorine and bromine, more preferably a fluorine atom.

  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 , — (CH ₂ ) _n —O—Si (R ⁵⁾ ) ₃ and-(C _{H 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 ~ alkenyl group of C _10), a linear or branched alkynyl group having 2 to 10 carbon atoms _(C 2 _{~C 10),} a cycloalkyl group having 5 to 12 carbon atoms _(C 5 _{~C 12),} to 6 carbon atoms -14 (C ₆ -C ₁₄ ) aryl group, C 6-14 (C ₆ -C ₁₄ ) halogenated or perhalogenated aryl group or C 7-24 (C ₇ -C ₂₄ ) aralkyl group Represents.

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} and the like, but are 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.

Here, R ⁷ represents a hydrogen atom or a linear or branched alkyl group having ₁ to ₅ carbon atoms (C _{1 to} C ₅ ).

  Examples of the alkyl group include methyl group, ethyl group, propyl group, i-propyl group, butyl group, i-butyl group, t-butyl, 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, a 1-methyl-1-cyclohexyl group, an isobornyl group, a 2-methyl-2-isobornyl group, a 2-methyl-2-adamantyl group, a tetrahydrofuranyl group, Examples thereof include a tetrahydropyranoyl group, a 3-oxocyclohexanoyl group, a mevalonic lactonyl group, a 1-ethoxyethyl group, and a 1-t-butoxyethyl group.

Other examples of R ⁶ include a dicyclopropylmethyl group (Dcpm) and a dimethylcyclopropylmethyl group (Dmcp) represented by the following chemical formula 5.

  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).

  As the crosslinkable norbornene-based monomer, there are a compound of a continuous polycyclic ring system and a compound of a linked multicyclic ring system.

  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).

［式中、Ｙは、メチレン（−ＣＨ_２−）基を表し、ｍは、０〜５の整数を表わす。ただし、ｍが０である場合、Ｙは、単結合である。］

[Wherein Y represents a methylene (—CH ₂ —) group, and m represents an integer of 0 to 5. However, when m is 0, Y is a single bond. ]

  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 monomer) include compounds represented by the following chemical formula (8).

［式中、ａは、それぞれ独立して、単結合または二重結合を表し、ｍは、それぞれ独立して、０〜５の整数を表し、Ｒ^９は、それぞれ独立して二価の炭化水素基、二価のエーテル基または二価のシリル基を表す。また、ｎは、０または１である。］

[Wherein, a independently represents a single bond or a double bond; m independently represents an integer of 0 to 5; and R ⁹ independently represents a divalent hydrocarbon. Represents a group, a divalent ether group or a divalent silyl group. N is 0 or 1. ]

  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 an alkylene group represented by the general formula:-(C _d H _2d )-(d is preferably an integer of 1 to 10). And a divalent aromatic group (aryl group).

The divalent alkylene group is preferably a linear or branched alkylene group having 1 to 10 carbon atoms (C _{1 to} C ₁₀ ), such as a methylene group, an ethylene group, a propylene group, a butylene group, a pentylene group, Examples include a hexylene group, a heptylene group, an octylene group, a nonylene group, and a 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 chemical formula 10 is dimethylbis [bicyclo [2.2.1] hept-2-ene-5-methoxy] silane, and is named dimethylbis (norbornenemethoxy) silane (“ Abbreviated as “SiX”).

［式中、ｎは、０〜４の整数を表す。］

[Wherein, n represents an integer of 0 to 4. ]

［式中、ｍおよびｎは、それぞれ、１〜４の整数を表す。］

[Wherein, m and n each represent an integer of 1 to 4. ]

  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. Moreover, the refractive index difference between the core part 94 and the clad part 95 can be increased, and the characteristics (optical transmission performance) of the core layer 93 (optical waveguide 9) 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.

［式Ｉａ、Ｉｂ中、それぞれ、Ｅ（Ｒ）_３は、第１５族の中性電子ドナー配位子を表し、Ｅは、周期律表の第１５族から選択される元素を表し、Ｒは、水素原子（またはその同位体の１つ）または炭化水素基を含む部位を表し、Ｑは、カルボキシレート、チオカルボキシレートおよびジチオカルボキシレートから選択されるアニオン配位子を表す。また、式Ｉｂ中、ＬＢは、ルイス塩基を表し、ＷＣＡは、弱配位アニオンを表し、ａは、１〜３の整数を表し、ｂは、０〜２の整数を表し、ａとｂとの合計は、１〜３であり、ｐおよびｒは、パラジウムカチオンと弱配位アニオンとの電荷のバランスをとる数を表す。］

[In the formulas Ia and Ib, E (R) ₃ represents a neutral electron donor ligand of group 15, respectively, E represents an element selected from group 15 of the periodic table, and R represents , Represents a moiety containing a hydrogen atom (or one of its isotopes) or a hydrocarbon group, and Q represents an anionic ligand selected from carboxylate, thiocarboxylate and dithiocarboxylate. In Formula Ib, LB represents a Lewis base, WCA represents a weakly coordinating anion, a represents an integer of 1 to 3, b represents an integer of 0 to 2, and a and b , P and r represent numbers that balance the charge of the palladium cation and the weakly coordinated anion. ]

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 . 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 a catalyst precursor includes (mainly) one containing at least one of Pd (OAc) ₂ (P (i-Pr) ₃ ) ₂ and Pd (OAc) ₂ (P (Cy) ₃ ) _2. 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 a substance that can be activated by irradiation with actinic radiation to change the activation temperature of the catalyst precursor (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. A compound (photoinitiator) that decomposes upon irradiation with actinic radiation and generates a cation such as a proton or other cation and a weakly coordinated anion (WCA) that can be substituted with a leaving group of the catalyst precursor ( (Mainly) is preferably used.

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.

  As a commercial product of such a promoter, for example, “RHODORSIL (registered trademark, the same applies hereinafter) PHOTOINITIATOR 2074 (CAS No. 178233-72-2) available from Rhodia USA, Cranberry, NJ "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, available from Toyo Ink Manufacturing Co., Ltd., Tokyo, Japan "TAG-371 (CAS No. 193957-53-8 “TTBPS-TPFPB (tris (4-tert-butylphenyl) sulfonium tetrakis (pentapentafluorophenyl) borate)”, available from Toyo Gosei Co., Ltd., Tokyo, Midori Chemical Industries, Tokyo, Japan Examples thereof include “NAI-105 (CAS No. 85342-62-7)” available from a corporation.

  When RHODORSIL PHOTOINITIATOR 2074 is used as the cocatalyst (first substance), ultraviolet rays (UV light) are preferably used as actinic radiation (chemical rays) described later, and mercury lamps ( A high-pressure mercury lamp) is preferably used. Thereby, ultraviolet rays (active radiation) having sufficient energy of less than 300 nm can be supplied to the layer 910, and RHODOLSIL PHOTOINITIATOR 2074 can be efficiently decomposed to generate the above-described cation 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, chrysenes, benzpyrenes, fluoranthenes, rubrenes, pyrenes, indanthrines, thioxanthen-9-ones (Thioxanthen-9-ones) and the like, and these are used alone or as a mixture.

  Specific examples of the sensitizer include 2-isopropyl-9H-thioxanthen-9-one, 4-isopropyl-9H-thioxanthen-9-one, 1-chloro-4-propoxythioxanthone, phenothiazine, and these Of the mixture.

  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 preferably 0.01% by weight or more, more preferably 0.5% by weight or more, and 1% by weight or more. More preferably. 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.

  Examples of the antioxidant include Ciba (registered trademark, the same applies hereinafter) IRGANOX (registered trademark, the same applies hereinafter) 1076 and Ciba IRGAFOS (registered trademark, available) from Ciba Specialty Chemicals of Tarrytown, New York. The same applies hereinafter.) 168 is preferably used.

  Other antioxidants include, for example, Ciba Irganox (registered trademark, hereinafter the same) 129, Ciba Irganox 1330, Ciba Irganox 1010, Ciba Cyanox (registered trademark, the same shall apply hereinafter) 1790, Ciba Irg. (Registered trademark) 3114, Ciba Irganox 3125, 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). ), Ether solvents such as anisole, diethylene glycol dimethyl ether (diglyme), diethylene glycol ethyl ether (carbitol), cellosolv solvents such as methyl cellosolve, ethyl cellosolve, phenyl cellosolve, aliphatic hydrocarbons such as hexane, pentane, heptane, cyclohexane Solvent, aromatic hydrocarbon solvent such as toluene, xylene, benzene, mesitylene, aromatic heterocyclic compound solvent such as pyridine, pyrazine, furan, pyrrole, thiophene, methylpyrrolidone, Amide solvents such as N, N-dimethylformamide (DMF) and N, N-dimethylacetamide (DMA), halogen compound solvents such as dichloromethane, chloroform and 1,2-dichloroethane, ethyl acetate, methyl acetate, ethyl formate, etc. Examples thereof include various organic solvents such as ester solvents, sulfur compound solvents such as dimethyl sulfoxide (DMSO) and sulfolane, and mixed solvents containing these.

  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 (see FIG. 5-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 may be formed in advance (separately formed) (for example, plate-shaped) or may be formed on the layer 910 by, for example, 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.

  Further, in FIG. 5B, an opening (window) 9351 equivalent to the pattern of the clad portion 95 to be formed shows that the mask is partially removed along the pattern of the non-irradiated region 940 of the active radiation 930. However, when using a photomask made of quartz glass, PET base material, or the like, a photomask provided with a shielding portion of active radiation 930 made of a shielding material made of metal such as chromium is used. You can also. 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.

The irradiation dose of the actinic radiation 930 is preferably in the range of about 0.1~9J / cm ^2, more preferably about ^{0.2~6J / cm 2, 0.2~3J / cm} 2 of about More preferably. 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 cocatalyst (first substance: cocatalyst) present in the irradiation region 925 irradiated with the active radiation 930 reacts by the action of the active radiation 930. (Binding) or decomposition to release (generate) cations (protons or other cations) and 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.

  Note that in the case where light having high directivity such as laser light is used as the active radiation 930, the 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 irradiated region 925, the monomer and its reaction product (polymer, cross-linked structure or branched structure) increase, and the structure derived from the monomer greatly affects the refractive index of the region, so that the first refraction The second refractive index lower than the 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. 5-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, and 0.1 to 1 hour. More preferred is the degree.

  Here, the core section 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 are preferably about 1 to 200 μm, respectively. More preferably, it is about 5-100 micrometers, More preferably, it is about 10-60 micrometers.

[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 is preferably about 70 to 100 ° C, and is about 80 to 90 ° C. Is more preferable.

  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 preferably set to 20 ° C. or more higher than the heating temperature in the second heat treatment, specifically, preferably about 90 to 180 ° C., 120 to 160 ° C. More preferred is the degree.

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 clad layer 91 (92) is formed on the support substrate 952 (see FIG. 5-D).

  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 acrylic resins, methacrylic resins, polycarbonate, polystyrene, epoxy resins, polyamides, polyimides, polybenzoxazoles, benzocyclobutene resins, and norbornene resins. 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. At this time, even when the optical element is heated to mount it, the clad layer 91 (92) can be prevented from being softened and deformed.

  Moreover, since it has high hydrophobicity, it is possible to obtain the clad layer 91 (92) that is less likely to undergo dimensional changes due to water absorption.

  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. In addition, since it is the same kind of material that is suitably used as the constituent material of the core layer 93, the adhesion with the core layer 93 is further increased, and delamination between the clad layer 91 (92) and the core layer 93 is achieved. 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) ring-opening copolymer of norbornene type monomer and non-conjugated diene or other monomer, and (co) polymerization if necessary And a ring-opening polymer such as a polymer obtained by hydrogenating the body. Examples of these polymers include random copolymers, block copolymers, and alternating copolymers.

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

  Among these, as the norbornene-based 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 and the adhesion between the clad layer 91 (92) and the core layer 93 can be further improved.

  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 a high affinity with the polymer used in the core layer 93 as described above, an interlayer between the clad layer 91 (92) and the core layer 93 is used. Separation can be prevented more reliably, and an optical waveguide 9 with 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 has high flexibility, so that high flexibility (flexibility) can be imparted to the clad layers 91 and 92 (optical waveguide 9).

  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, but generally contains a norbornene repeating unit having a substituent containing an aryl group, the refractive index is generally 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.

［式中、Ｒは、炭素数１〜１０のアルキル基を表し、ａは、０〜３の整数を表し、ｂは、１〜３の整数を表し、ｐ／ｑが２０以下である。］

[Wherein R represents an alkyl group having 1 to 10 carbon atoms, a represents an integer of 0 to 3, b represents an integer of 1 to 3, and p / q is 20 or less. ]

  Among the norbornene-based polymers represented by Chemical formula 18, a compound in which R is an alkyl group having 4 to 10 carbon atoms and a and b are each 1, for example, a copolymer of butylbornene and methylglycidyl ether norbornene A copolymer of hexyl norbornene and methyl glycidyl ether norbornene, a copolymer of decyl norbornene and methyl glycidyl ether norbornene, and the like are preferable.

［式中、Ｒは、炭素数１〜１０のアルキル基を表し、Ｒ^１は、水素原子またはメチル基を表し、ａは、０〜３の整数を表し、ｐ／ｑが２０以下である。］

[Wherein, R represents an alkyl group having 1 to 10 carbon atoms, R ¹ represents a hydrogen atom or a methyl group, a represents an integer of 0 to 3, and p / q is 20 or less. ]

  Among the norbornene-based polymers represented by Chemical formula 19, compounds in which R is an alkyl group having 4 to 10 carbon atoms and a is 1, for example, butylbornene and 2- (5-norbornenyl) methyl acrylate And a copolymer of hexylnorbornene and 2- (5-norbornenyl) methyl acrylate, a copolymer of decylnorbornene and 2- (5-norbornenyl) methyl acrylate, and the like.

［式中、Ｒは、炭素数１〜１０のアルキル基を表し、Ｘは、それぞれ独立して、炭素数１〜３のアルキル基を表し、ａは、０〜３の整数を表し、ｐ／ｑが２０以下である。］

[Wherein, R represents an alkyl group having 1 to 10 carbon atoms, X represents each independently an alkyl group having 1 to 3 carbon atoms, a represents an integer of 0 to 3, and p / q is 20 or less. ]

  Among the norbornene-based polymers represented by Chemical Formula 20, in particular, compounds in which R is an alkyl group having 4 to 10 carbon atoms, a is 1 or 2, and X is a methyl group or an ethyl group, such as butylbornene Copolymer of norbornenylethyltrimethoxysilane, copolymer of hexylnorbornene and norbornenylethyltrimethoxysilane, copolymer of decylnorbornene and norbornenylethyltrimethoxysilane, copolymer of butylbornene and triethoxysilylnorbornene, hexyl Copolymers of norbornene and triethoxysilyl norbornene, copolymers of decyl norbornene and triethoxysilyl norbornene, copolymers of butylbornene and trimethoxysilyl norbornene, hexyl norbornene and tri Copolymers of butoxy silyl norbornene copolymer and the like of decyl norbornene and trimethoxysilyl norbornene are preferred.

［式中、Ｒは、炭素数１〜１０のアルキル基を表し、Ａ^１およびＡ^２は、それぞれ独立して、下記化２２〜２４で表される置換基を表すが、同時に同一の置換基であることはない。また、ｐ／ｑ＋ｒが２０以下である。］

[Wherein, R represents an alkyl group having 1 to 10 carbon atoms, and A ¹ and A ² each independently represent a substituent represented by the following chemical formulas 22 to 24, but at the same time, the same substituent Never. Moreover, p / q + r is 20 or less. ]

［式中、ａは、０〜３の整数を表し、ｂは、１〜３の整数を表す。］

[Wherein, a represents an integer of 0 to 3, and b represents an integer of 1 to 3. ]

［式中、Ｒ^１は、水素原子またはメチル基を表し、ａは、０〜３の整数を表す。］

[Wherein, R ¹ represents a hydrogen atom or a methyl group, and a represents an integer of 0 to 3. ]

［式中、Ｘは、それぞれ独立して、炭素数１〜３のアルキル基を表し、ａは、０〜３の整数を表す。］

[In formula, X represents a C1-C3 alkyl group each independently, and a represents the integer of 0-3. ]

  As the norbornene-based polymer represented by Chemical formula 21, for example, any of butylbornene, hexylnorbornene or decylnorbornene, 2- (5-norbornenyl) methyl acrylate, norbornenylethyltrimethoxysilane, triethoxysilyl Terpolymers with either norbornene or trimethoxysilyl norbornene, terpolymers of either butylbornene, hexyl norbornene or decyl norbornene with 2- (5-norbornenyl) methyl acrylate and methylglycidyl ether norbornene, butylbornene, hexyl norbornene or One of decyl norbornene, methyl glycidyl ether norbornene, norbornenyl ethyl trimethoxysilane, triethoxysilyl norbornene Terpolymers, etc. with either Nen or trimethoxysilyl norbornene.

［式中、Ｒは、炭素数１〜１０のアルキル基を表し、Ｒ^２は、水素原子、メチル基またはエチル基を表し、Ａｒは、アリール基を表し、Ｘ^１は、酸素原子またはメチレン基を表し、Ｘ^２は、炭素原子またはシリコン原子を表し、ａは、０〜３の整数を表し、ｃは、１〜３の整数を表し、ｐ／ｑが２０以下である。］

[Wherein, R represents an alkyl group having 1 to 10 carbon atoms, R ² represents a hydrogen atom, a methyl group or an ethyl group, Ar represents an aryl group, and X ¹ represents an oxygen atom or a methylene group. X ² represents a carbon atom or a silicon atom, a represents an integer of 0 to 3, c represents an integer of 1 to 3, and p / q is 20 or less. ]

Of the norbornene polymers represented by Chemical Formula 25, in particular, R is an alkyl group having 4 to 10 carbon atoms, X ¹ is an oxygen atom, X ² is a silicon atom, Ar is a phenyl group, and R ² is methyl. A group in which a is 1 and c is 2, for example, a copolymer of butylbornene and diphenylmethylnorbornenemethoxysilane, a copolymer of hexylnorbornene and diphenylmethylnorbornenemethoxysilane, a copolymer of decylnorbornene and diphenylmethylnorbornenemethoxysilane, etc. Or R is an alkyl group having 4 to 10 carbon atoms, X ¹ is a methylene group, X ² is a carbon atom, Ar is a phenyl group, R ² is a hydrogen atom, a is 0, and c is 1, for example, , A copolymer of butylbornene and phenylethylnorbornene, hexylnorbornene and Copolymers of E sulfonyl ethyl norbornene copolymer, etc. of decyl norbornene and phenyl ethyl norbornene are preferred.

  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.

  As the radical generator, for example, 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, at least a part of the norbornene-based polymer in the clad layer 91 (92) can be crosslinked via the crosslinkable 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 catalyst precursors include [Pd (PCy ₃ ) ₂ (O ₂ CCH ₃ ) (NCCH ₃ )] tetrakis (pentafluorophenyl) borate, [2-methylly Pd (PCy3) 2] tetrakis (pentafluorophenyl). ) Borate, [Pd (PCy3) 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 clad layers 91 and 92 is not particularly limited, but it is usually preferably about 1 to 200 μm, more preferably about 5 to 100 μm, and about 10 to 60 μm. More preferably. 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. 5-E).

Then, as indicated by an arrow in FIG. 5E, pressure is applied from the upper surface side of the support substrate 952 on which the cladding layer 92 is formed, and the cladding layers 91 and 92 and the core layer 93 are pressure bonded.
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 appropriately determined depending on the constituent materials of the clad layers 91 and 92 and the core layer 93, and 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 both contain the same norbornene-based polymer, but contain a reaction product of a norbornene-based monomer having a refractive index different from that of the norbornene-based polymer. Due to the different amounts, the refractive indices are different from each other.

  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 clad portion 95 but also high adhesion between the core layer 93, the clad layer 91, and the clad layer 92 can be obtained. 9, even when deformation such as bending occurs, peeling between the core portion 94 and the clad portion 95 and delamination between the core layer 93 and the clad layers 91 and 92 hardly occur. It is also possible to prevent micro cracks from occurring. 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, and the rest is the same as the first 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, those having at least one of an —O— structure, an —Si—aryl structure and an —O—Si— structure in its molecular structure are preferable. Such an acid leaving group is released relatively easily by the action of a cation.

  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 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 actinic radiation 930 through the mask 935, the release agent present in the irradiation region 925 irradiated with the actinic radiation 930 reacts (bonds) or decomposes by the action of the actinic radiation 930, and becomes a cation. Liberate (generate) protons (or other cations) and weakly coordinating anions (WCA).

  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.
As a result, the leaving group detached (cut) from the polymer 915 is removed from the irradiated region 925 or rearranged or cross-linked in 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. .

Moreover, the process of 1 time or several times of heat processing (for example, about 150-200 degreeC x about 1 to 8 hours) can also be added as needed.
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 clad portion 95 but also high adhesion between the core layer 93, the clad layer 91, and the clad layer 92 can be obtained. 9, even when deformation such as bending occurs, peeling between the core portion 94 and the clad portion 95 and delamination between the core layer 93 and the clad layers 91 and 92 hardly occur. It is also possible to prevent micro cracks from occurring. 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), and a catalyst precursor (second 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 cocatalyst (first substance: cocatalyst) present in the irradiation region 925 irradiated with the active radiation 930 reacts by the action of the active radiation 930. Alternatively, it decomposes to liberate (generate) cations (protons or other cations) and 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).

  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 unirradiated region 940, and the refractive index is lowered to be 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 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 the monomer diffuses from the unirradiated region 940 and collects in the irradiated region 925 in order to eliminate this.

  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 includes a norbornene-based polymer having a main chain and a leaving group that is branched from the main chain and at least a part of the molecular structure can be detached from the main chain. The core portion 94 and the clad portion 95 are different in the number of leaving groups bonded to the main chain, and the content of the norbornene monomer reactant having a different refractive index from that of the norbornene polymer. Are different in refractive index, and the clad layers 91 and 92 are mainly composed of a norbornene-based polymer whose refractive index is lower than that of the core portion 94 of the core 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 clad portion 95 but also high adhesion between the core layer 93, the clad layer 91, and the clad layer 92 can be obtained. 9, even when deformation such as bending occurs, peeling between the core portion 94 and the clad portion 95 and delamination between the core layer 93 and the clad layers 91 and 92 hardly occur. It is also possible to prevent micro cracks from occurring. 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.

  6A to 6E are cross-sectional views schematically showing a process example of the fourth method for manufacturing an 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 same material as described in the first to third manufacturing methods can be used for the core layer forming material 900 and the cladding layer forming material.

  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. 6A). 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. 6-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. 6-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. Thereby, 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 the stacked body 2000 is irradiated with active radiation 930 through the mask 935 (see FIG. 6D). .

  When the stacked body 2000 is irradiated with the active radiation 930 through the mask 935, the promoter (first substance: cocatalyst) present in the irradiation region 925 irradiated with the active radiation 930 of the second layer 1120 is: It reacts or decomposes by the action of actinic radiation 930 to liberate (generate) cations (protons or other cations) and 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).

[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 the monomer diffuses from the unirradiated region 940 and collects in the irradiated region 925 in order to eliminate this.

  As a result, in the irradiated region 925, the monomer and its reaction product (polymer, cross-linked structure or branched structure) increase, and the structure derived from the monomer greatly affects the refractive index of the region, so that the first refraction The second refractive index lower than the 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. 6-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.

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

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

  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).

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

  In each of the above-described embodiments, the configuration including both the light-emitting element 10 and the light-receiving element 11 as the element has been described. However, either one of the light-emitting element 10 and the light-receiving element 11 may be mounted. Of course, two or more sets 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.

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 the sectional view on the AA line in FIG. It is sectional drawing which shows embodiment of the optical waveguide board | substrate of this invention. It is sectional drawing which shows typically the process example of the 1st manufacturing method of the optical waveguide structure of this invention. It is sectional drawing which shows typically the process example of the 1st manufacturing method of the optical waveguide structure of this invention. It is sectional drawing which shows typically the process example of the 1st manufacturing method of the optical waveguide structure of this invention. It is sectional drawing which shows typically the process example of the 1st manufacturing method of the optical waveguide structure of this invention. It is sectional drawing which shows typically the process example of the 1st manufacturing method of the optical waveguide structure of this invention. It is sectional drawing which shows typically the example of a process of the 4th manufacturing method of the optical waveguide structure of this invention. It is sectional drawing which shows typically the example of a process of the 4th manufacturing method of the optical waveguide structure of this invention. It is sectional drawing which shows typically the example of a process of the 4th manufacturing method of the optical waveguide structure of this invention. It is sectional drawing which shows typically the example of a process of the 4th manufacturing method of the optical waveguide structure of this invention. It is sectional drawing which shows typically the example of a process of the 4th manufacturing method of the optical waveguide structure of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical waveguide structure 2 Semiconductor layer (semiconductor substrate)
DESCRIPTION OF SYMBOLS 21 Translucent part 22, 23 Through-hole 3 Insulating layer 4 Solder 51, 52, 53 Conductor layer 55, 56, 57 Conductor layer 6 Optical waveguide board | substrate 7 Substrate 8 Through-hole (through hole)
81, 82, 83, 84 Conductor post (conductive material)
DESCRIPTION OF SYMBOLS 9 Optical waveguide 91 Cladding layer 92 Cladding layer 93 Core layer 94 Core part 95 Cladding part 96a, 96b, 96c, 96d Optical path conversion part 961a, 961b, 961c, 961d Reflecting surface 10 Light emitting element 101 Light emitting part 103 Terminal 11 Light receiving element 111 Light receiving Part 113 Terminal 12 Electronic circuit element (semiconductor element)
123, 125, 127 Terminal 13 Electronic circuit element (semiconductor element)
133, 135, 137 Terminal 900 Core layer forming material 910 Layer 915 Polymer 920 Additive 925 Irradiated region 930 Actinic radiation 935 Mask 9351 Open 940 Unirradiated region 951, 952 Support substrate 1000 Support substrate 1110 First layer 1120 Second layer Layer 1130 Third layer 2000 Laminate

Claims (62)

An optical waveguide structure comprising: a semiconductor layer composed of a semiconductor; and an optical waveguide having a core part and a cladding part having different refractive indexes, and at least a part of which is embedded in the semiconductor layer,
The core part is a material containing a polymer mainly composed of a norbornene-based polymer and a monomer mainly composed of a norbornene-based monomer that is compatible with the polymer and has a refractive index different from that of the polymer. It is formed in a desired shape in the core layer obtained by selectively irradiating the active radiation to the layer composed of a material whose refractive index changes by irradiation and heating of radiation ,
Before SL core layer, followed by heat treatment to the layer, in one of the regions of the non-irradiated regions of the irradiation region or the active radiation active radiation is irradiated by reacting the monomer, the other The unreacted monomer moves from one region to the other region to cause a refractive index difference between the irradiated region and the unirradiated region, and either the irradiated region or the unirradiated region is An optical waveguide structure characterized in that a core portion is obtained and the other is obtained as the clad portion. Comprising at least one of an element having a light emitting part and a terminal and an element having a light receiving part and a terminal;
The optical waveguide structure according to claim 1, wherein at least a part of the element is embedded in the semiconductor layer. Comprising at least one electronic circuit element for driving the element or processing an output signal of the element;
The optical waveguide structure according to claim 2, wherein at least a part of the electronic circuit element is embedded in the semiconductor layer. Comprising at least one electronic circuit element for driving the element or processing an output signal of the element;
The optical waveguide structure according to claim 2, wherein the electronic circuit element is mounted on one side of the semiconductor layer.   The optical waveguide structure according to any one of claims 1 to 4, further comprising an optical path conversion unit that bends an optical path of transmission light transmitted through the core unit.   The optical waveguide structure according to claim 5, wherein the optical path conversion unit is formed at a position overlapping the light emitting unit or the light receiving unit of the element in plan view.   The optical waveguide structure according to claim 5, wherein the optical path conversion unit has a reflection surface that reflects at least a part of the transmission light.   The optical waveguide according to any one of claims 5 to 7, further comprising a translucent part having translucency with respect to transmission light transmitted through the core unit, between the optical path conversion unit and the light emitting unit or the light receiving unit. Structure. A light-emitting element having a light-emitting part and a terminal, a light-receiving element having a light-receiving part and a terminal, and a transmission that is formed in a position overlapping each of the light-emitting part and the light-receiving part in plan view and transmitted through the core part A light emitting unit side optical path conversion unit and a light receiving unit side optical path conversion unit that bends the optical path of light;
The transmission light emitted from the light emitting unit is configured to be received by the light receiving unit sequentially through the light emitting unit side optical path conversion unit, the core unit, and the light receiving unit side optical path conversion unit,
The optical waveguide structure according to claim 1, wherein the light emitting element and the light receiving element are embedded in the semiconductor layer.   The optical waveguide structure according to claim 1, further comprising an insulating layer.   The optical waveguide structure according to claim 1, comprising a conductor layer.   The optical waveguide structure according to claim 11, further comprising a conductor post that is electrically connected to the conductor layer and extends in a thickness direction of the layer.   The optical waveguide structure according to claim 1, wherein the semiconductor layer is mainly made of silicon.   The optical waveguide structure according to claim 1, wherein a thickness of the semiconductor layer is 1 to 100 times a thickness of the optical waveguide.   The optical waveguide structure according to claim 1, wherein at least a part of the optical waveguide is embedded in the semiconductor layer. The material whose refractive index is changed is further a first substance activated by irradiation of the actinic radiation and a second substance capable of initiating a reaction of the monomer, and the activated first substance And a second substance whose activation temperature changes by the action of
The core layer activates the first substance and changes an activation temperature of the second substance in the irradiated region of the layer,
Next, by applying heat treatment to the layer, the second substance whose activation temperature has not changed or the second substance whose activation temperature has changed is activated, whichever has the lower activation temperature. The optical waveguide structure according to any one of claims 1 to 15, wherein the optical waveguide structure is obtained by reacting the monomer in either the irradiated region or the non-irradiated region of the active radiation.   The first substance includes a compound that generates a cation and a weakly coordinating anion upon irradiation with the active radiation, and the second substance has an activation temperature due to the action of the weakly coordinating anion. The optical waveguide structure according to claim 16, wherein is changed.   The activation temperature of the second substance is lowered by the action of the activated first substance, and the second substance is activated without being irradiated with the actinic radiation by heating at a temperature higher than the temperature of the heat treatment. The optical waveguide structure according to claim 16 or 17, wherein: The optical waveguide structure according to claim 18, wherein the second substance includes a compound represented by the following formula Ia.
(E (R) ₃ ) ₂ Pd (Q) ₂ ... (Ia)
[Wherein E (R) ₃ represents a neutral electron donor ligand of Group 15; E represents an element selected from Group 15 of the periodic table; and R represents a hydrogen atom (or One of its isotopes) or a moiety containing a hydrocarbon group, Q represents an anionic ligand selected from carboxylate, thiocarboxylate and dithiocarboxylate. ] The optical waveguide structure according to claim 18 or 19, wherein the second substance includes a compound represented by the following formula Ib.
[(E (R) ₃ ) _a Pd (Q) (LB) _b ] _p [WCA] _r (Ib)
[Wherein E (R) ₃ represents a neutral electron donor ligand of Group 15; E represents an element selected from Group 15 of the periodic table; and R represents a hydrogen atom (or One of its isotopes) or a moiety containing a hydrocarbon group, Q represents an anionic ligand selected from carboxylate, thiocarboxylate and dithiocarboxylate, LB represents a Lewis base, WCA Represents a weakly coordinating anion, a represents an integer of 1 to 3, b represents an integer of 0 to 2, the sum of a and b is 1 to 3, p and r are This represents the number that balances the charge between the palladium cation and the weakly coordinated anion. ]   21. The optical waveguide structure according to claim 20, wherein p and r are each selected from an integer of 1 or 2.   The optical core according to any one of claims 16 to 21, wherein the core layer is obtained by heat-treating the layer at a second temperature higher than the temperature of the heat-treatment after the heat-treatment. Waveguide structure.   23. The core layer according to claim 22, wherein the core layer is obtained by heat-treating the layer at a third temperature higher than the second temperature after the heat treatment at the second temperature. Optical waveguide structure.   The optical waveguide structure according to claim 23, wherein the third temperature is higher than the second temperature by 20 ° C or more.   25. The optical waveguide structure according to claim 16, wherein the monomer includes a crosslinkable monomer. The monomer, as pre Symbol crosslinking monomer, the optical waveguide structure according to claim 25 in which comprises dimethyl bis (norbornene methoxy) silane. The polymer has a leaving group capable of leaving at least a part of the molecular structure from the main chain by the action of the activated first substance, and the layer is selectively irradiated with the actinic radiation. when the said in the irradiation region, the optical waveguide structure according to any one of claims 16 to 26 wherein the leaving group of the polymer is disengaged. The first substance includes a compound that generates a cation and a weakly coordinating anion upon irradiation with the actinic radiation, and the leaving group is an acid leaving group that is released by the action of the cation. 28. An optical waveguide structure according to claim 27 . The core part and the clad part are different from each other in the number of the leaving groups bonded to the main chain, and different in the content of a reactant of a monomer having a refractive index different from that of the polymer. The optical waveguide structure according to claim 27 or 28 , wherein the refractive indexes thereof are different. An optical waveguide structure comprising: a semiconductor layer composed of a semiconductor; and an optical waveguide having a core part and a cladding part having different refractive indexes, and at least a part of which is embedded in the semiconductor layer,
The core part is a substance that is activated by irradiation with actinic radiation, a main chain, a branch from the main chain, and a release from which at least part of the molecular structure can be detached from the main chain by the action of the activated substance A core layer obtained by selectively irradiating the active radiation to a layer composed of a material having a refractive index that changes by irradiation with active radiation . In the desired shape,
The core layer is, by selectively irradiating the actinic radiation for the previous SL layer, the irradiation area irradiated with the active radiation, to activate the material, leaving the cleavable groups of the polymer Then, by causing a refractive index difference between the irradiation region and the non-irradiation region of the active radiation, one of the irradiation region and the non-irradiation region is the core portion, and the other is the cladding portion. Is obtained as
The leaving group has an -O-Si-diphenyl structure. The optical waveguide structure according to claim 30 , wherein the core layer is obtained by performing a heat treatment on the layer after the irradiation with the active radiation. The substance includes a compound that generates a cation and a weakly coordinating anion upon irradiation with the actinic radiation, and the leaving group is an acid leaving group that is released by the action of the cation. 30. The optical waveguide structure according to 30 or 31 . The optical waveguide structure according to any one of claims 27 to 32 , wherein the detachable group causes a decrease in the refractive index of the polymer by the detachment. The active radiation, an optical waveguide structure according to any one of claims 16 to 33 and has a peak wavelength in the range of 200 to 450 nm. The dose of the actinic radiation is, the optical waveguide structure according to any one of claims 16 a 0.1~9J / cm ² 34. 36. The optical waveguide structure according to any one of claims 16 to 35 , wherein the active radiation is applied to the layer through a mask. The optical waveguide structure according to any one of claims 16 to 36 , wherein the layer further contains an antioxidant. The optical waveguide structure according to any one of claims 16 to 37 , wherein the layer further contains a sensitizer. The optical waveguide structure according to any one of claims 30 to 32 , wherein the polymer is mainly a norbornene-based polymer. The optical waveguide structure according to claim 39 , wherein the norbornene-based polymer is an addition polymer.   The core part is composed of a first norbornene-based material as a main material, and the cladding part is composed of a second norbornene-based material having a lower refractive index than that of the first norbornene-based material. The optical waveguide structure according to any one of claims 1 to 15. The first norbornene-based material and the second norbornene-based material both contain the same norbornene-based polymer and contain a reaction product of a norbornene-based monomer having a refractive index different from that of the norbornene-based polymer. 42. The optical waveguide structure according to claim 41 , wherein the refractive indexes thereof are different due to different amounts. 43. The light according to claim 42 , wherein the reactant is at least one of a polymer of the norbornene-based monomer, a crosslinked structure that crosslinks the norbornene-based polymers, and a branched structure that branches from the norbornene-based polymer. Waveguide structure. The norbornene polymer, the optical waveguide structure according to claim 42 or 43 in which comprises a repeating unit of the aralkyl norbornene. 44. The optical waveguide structure according to claim 42 or 43 , wherein the norbornene-based polymer includes a repeating unit of benzylnorbornene. 44. The optical waveguide structure according to claim 42 or 43 , wherein the norbornene-based polymer includes a repeating unit of phenylethyl norbornene. 44. The optical waveguide structure according to claim 42 or 43 , wherein the norbornene-based polymer includes a repeating unit of alkyl norbornene. 44. The optical waveguide structure according to claim 42 or 43 , wherein the norbornene-based polymer contains a repeating unit of hexyl norbornene. The optical waveguide structure according to any one of the norbornene-based polymer, to 42 claims is an addition polymer 48. The optical waveguide structure according to any one of claims 16 to 49 , further comprising a cladding layer provided in contact with at least one surface of the core layer and having a refractive index lower than that of the core portion. 51. The optical waveguide structure according to claim 50 , wherein the cladding layer is composed of a norbornene polymer as a main material. The optical waveguide structure according to claim 51 , wherein the norbornene-based polymer is an addition polymer. 53. The optical waveguide structure according to claim 51 , wherein the norbornene-based polymer includes a repeating unit of alkyl norbornene. The optical waveguide structure according to any one of the norbornene-based polymer, to the claims 51 to include repeating units of norbornene having a substituent containing a polymerizable group 53. The repeating unit of norbornene having a substituent containing a polymerizable group is a repeating unit of norbornene having a substituent containing an epoxy group, a repeating unit of norbornene having a substituent containing a (meth) acryl group, and an alkoxysilyl group 55. The optical waveguide structure according to claim 54 , wherein the optical waveguide structure is at least one of repeating units of norbornene having a substituent containing. 56. The optical waveguide structure according to claim 54 or 55 , wherein at least a part of the norbornene-based polymer is crosslinked at a polymerizable group. The norbornene polymer, the optical waveguide structure according to any one of claims 51 comprising repeating units of norbornene having a substituent containing an aryl group 53. 58. The optical waveguide structure according to claim 57 , wherein at least a part of the norbornene-based polymer is crosslinked through a crosslinking agent. The average of the cladding layer, the optical waveguide structure according to any of the the preceding claims 51 0.1 to 1.5 times the average thickness of the core layer 58. An optical waveguide substrate comprising at least one optical waveguide structure according to any one of claims 16 to 59 mounted on a substrate. 61. The optical waveguide substrate according to claim 60 , wherein the substrate has a semiconductor layer different from the semiconductor layer. The optical waveguide substrate according to claim 60 or 61 , wherein the substrate has an optical waveguide different from the optical waveguide.

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