JP2006323319A - Optical waveguide structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical waveguide structure that has much latitude of design of a pattern shape, that facilitates formation of a core (optical path) with a high dimensional accuracy, and that is equipped with an optical waveguide excellent in durability. <P>SOLUTION: The optical waveguide structure 1 is equipped with a block-shaped optical waveguide body 2 and five light emitting elements 61-65. The optical waveguide body 2 is composed by laminating a plurality of cladding layers and a plurality of core layers in a prescribed order, wherein each core layer has a core part 94 and a cladding part 95 formed in a prescribed pattern. The core part 94 is a portion forming the optical path for transmission light and is three-dimensionally arranged inside the optical waveguide body 2. The core part 94 is, as the main material, of a resin composition containing, for example, a norbornene based resin. The core part 94 is formed into a desired shape by selectively irradiating the core layer 93 with an active radiation, wherein the core layer 93 is composed of a material whose refractive index varies by the irradiation of the active radiation or by further heating. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an optical waveguide structure.

  In recent years, optical branching couplers (optical couplers), optical multiplexers / demultiplexers, and the like have been developed as optical components in the field of optical communications, and optical waveguide devices used for these are promising. As this optical waveguide type element (hereinafter also simply referred to as “optical waveguide”), there are polymer optical waveguides that are easy to manufacture (patterning) and are versatile, in addition to the 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. In particular, since the arrangement of the optical path (core part) is planar, the degree of freedom in designing the optical path 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. To provide a body.

Such an object is achieved by the present inventions (1) to (70) below.
(1) having an optical waveguide body having a core part forming an optical path and a clad part formed on the outer periphery of the core part and having a refractive index different from that of the core part;
The core portion is three-dimensionally arranged in the optical waveguide body,
The core part is formed into a desired shape by selectively irradiating the active radiation to a core layer made of a material whose refractive index changes by irradiation with active radiation or by further heating. An optical waveguide structure characterized in that

  (2) The optical waveguide structure according to (1), wherein the core portion has a portion extending in at least one of the X, Y, and Z directions orthogonal to each other.

  (3) The optical waveguide structure according to (1), wherein the core portion has a portion extending in at least two of the X, Y, and Z directions orthogonal to each other.

  (4) The optical waveguide structure according to any one of (1) to (3), wherein the optical waveguide body has a portion in which a clad layer and a core layer constituting the clad portion are alternately laminated.

  (5) Any of the above (1) to (4), wherein the optical waveguide main body has a portion in which two or more laminated bodies each formed by joining the clad layers constituting the clad portion are laminated on both surfaces of the core layer. An optical waveguide structure according to claim 1.

  (6) The optical waveguide structure according to any one of (1) to (5), wherein the optical waveguide main body includes a core layer stacked portion in which a plurality of the core layers are stacked.

  (7) The optical waveguide structure according to any one of (4) to (6), including a portion configured to transmit and receive transmission light between the core portions formed between different core layers. .

  (8) The optical waveguide structure according to any one of (1) to (7), further including an optical path conversion unit that bends an optical path of transmission light transmitted through the core unit.

  (9) The optical waveguide structure according to (8), wherein the optical path conversion unit has a reflecting surface that reflects at least a part of the transmission light.

  (10) The optical waveguide structure according to (8) or (9), wherein the optical path conversion unit has a function of dividing an optical path of the transmission light in a plurality of directions.

  (11) The core part is arranged so that transmission light incident on a predetermined part of the core part from the outside of the optical waveguide body does not intersect with other parts of the core part. 10) The optical waveguide structure according to any one of 10).

  (12) The optical waveguide structure according to any one of (1) to (11), wherein the core portion includes a portion where an optical path branches and / or merges.

  (13) When transmission light is incident on a predetermined part of the core part from one incident direction of X, Y, and Z directions orthogonal to each other, the transmission light is transmitted from another part of the core part to the incident direction. The optical waveguide structure according to any one of (1) to (12), wherein the optical waveguide structure is configured to emit in an orthogonal direction.

  (14) The optical waveguide structure according to any one of (1) to (13), wherein the optical waveguide body is configured with an inclined surface having at least one surface inclined with respect to a transverse section of the core portion. .

  (15) The optical waveguide structure according to any one of (1) to (14), wherein the optical waveguide structure includes at least one element having a light emitting part or a light receiving part and a terminal.

  (16) The optical waveguide structure according to any one of (1) to (15), wherein the element is bonded to a surface of the optical waveguide body.

  (17) The optical waveguide structure according to any one of (1) to (15), wherein at least a part of the element is installed inside the optical waveguide body.

  (18) The optical waveguide structure according to any one of (15) to (17), which includes two or more elements that operate independently of each other, operate in conjunction with each other, or operate synchronously.

  (19) The optical waveguide structure according to any one of (1) to (18), having a conductor layer.

  (20) The optical waveguide structure according to any one of (15) to (18), further including a conductor layer, wherein the terminal is electrically connected to the conductor layer.

(21) The core layer comprises a polymer, a monomer compatible with the polymer and having a refractive index different from that of the polymer, a first substance activated by irradiation with actinic radiation, and the reaction of the monomer. Forming a layer comprising a second substance that can be initiated and a second substance that has an activation temperature changed by the action of the activated first substance;
Thereafter, the first substance is activated in the irradiation region irradiated with the actinic radiation by selectively irradiating the layer with the actinic radiation, and the activation temperature of the second substance. Change
Next, by performing heat treatment on the layer, the lower one of the second substance or the second substance whose activation temperature has changed is activated, and the irradiation region or the Either one of the irradiated region and the unirradiated region is caused by reacting the monomer in any one of the unirradiated regions of actinic radiation to generate a refractive index difference between the irradiated region and the unirradiated region. The optical waveguide structure according to any one of (1) to (20), wherein the optical waveguide structure is obtained with the core portion and the other as the clad portion.

  (22) The core layer was obtained by collecting unreacted monomer from the other region as the reaction of the monomer progressed in either the irradiated region or the unirradiated region of the layer. The optical waveguide structure according to (21), which is a material.

  (23) 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 (21) or (22), wherein the activation temperature varies.

  (24) The activation temperature of the second substance is lowered by the action of the activated first substance, and the irradiation with the active radiation is accompanied by heating at a temperature higher than the temperature of the heat treatment. The optical waveguide structure according to any one of (21) to (23), wherein the optical waveguide structure is activated completely.

(25) The optical waveguide structure according to (24), 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. ]

(26) The optical waveguide structure according to (24) or (25), 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. ]

  (27) The optical waveguide structure according to (26), wherein p and r are each selected from an integer of 1 or 2.

  (28) The said core layer is obtained by heat-processing the said layer at 2nd temperature higher than the temperature of the said heat processing after the said heat processing of said (21) thru | or (27) The optical waveguide structure according to any one of the above.

  (29) 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 (28). ).

  (30) The optical waveguide structure according to (29), wherein the third temperature is 20 ° C. or more higher than the second temperature.

  (31) The optical waveguide structure according to any one of (21) to (30), wherein the monomer includes a crosslinkable monomer.

  (32) The optical waveguide structure according to any one of (21) to (31), wherein the monomer is mainly a norbornene-based monomer.

  (33) The optical waveguide structure according to (31), wherein the monomer is mainly a norbornene-based monomer, and includes dimethylbis (norbornenemethoxy) silane as the crosslinkable monomer.

  (34) 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 actinic radiation for the layer. The optical waveguide structure according to any one of the above (21) to (33), wherein the leaving group of the polymer is released in the irradiated region when irradiated with.

  (35) The first substance includes a compound that generates a cation and a weakly coordinated anion upon irradiation with the actinic radiation, and the leaving group is removed by the action of the cation. The optical waveguide structure according to the above (34), which is a functional group.

(36) The core layer has a substance activated by irradiation with actinic radiation, a main chain and a branch from the main chain, and at least a part of the molecular structure is detached from the main chain by the action of the activated substance. Forming a layer comprising a polymer having a leaving group capable of
Thereafter, by selectively irradiating the layer with the actinic radiation, the substance is activated in the irradiation region irradiated with the actinic radiation, and the leaving group of the polymer is released, By producing a refractive index difference between the irradiation region and the non-irradiation region of the active radiation, either the irradiation region or the non-irradiation region was obtained as the core portion, and the other was obtained as the cladding portion. The optical waveguide structure according to any one of (1) to (20) above.

  (37) The optical waveguide structure according to (36), wherein the core layer is obtained by performing heat treatment on the layer after the irradiation with the active radiation.

  (38) 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. An optical waveguide structure according to (36) or (37) above.

  (39) The light-emitting device according to (35) or (38), wherein the acid leaving group has at least one of an -O- structure, an -Si-aryl structure, and an -O-Si- structure. Waveguide structure.

  (40) The optical waveguide structure according to any one of (34) to (39), wherein the leaving group causes a decrease in the refractive index of the polymer due to the leaving.

  (41) The optical waveguide structure according to (40), wherein the leaving group is at least one of a -Si-diphenyl structure and a -O-Si-diphenyl structure.

  (42) The optical waveguide structure according to any one of (21) to (41), wherein the active radiation has a peak wavelength in a range of 200 to 450 nm.

(43) The optical waveguide structure according to any one of (21) to (42), wherein an irradiation amount of the active radiation is 0.1 to 9 J / cm ² .

  (44) The optical waveguide structure according to any one of (21) to (43), wherein the active radiation is applied to the layer through a mask.

  (45) The optical waveguide structure according to any one of (21) to (44), wherein the layer further includes an antioxidant.

  (46) The optical waveguide structure according to any one of (21) to (45), wherein the layer further includes a sensitizer.

  (47) The optical waveguide structure according to any one of (21) to (46), wherein the polymer is mainly a norbornene-based polymer.

  (48) The optical waveguide structure according to (47), wherein the norbornene-based polymer is an addition polymer.

  (49) The core portion is configured with a first norbornene-based material as a main material, and the cladding portion is configured with 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 the above (1) to (20).

  (50) The first norbornene-based material and the second norbornene-based material both contain the same norbornene-based polymer, and a reaction of a norbornene-based monomer having a refractive index different from that of the norbornene-based polymer. The optical waveguide structure according to the above (49), wherein the refractive indexes thereof are different due to different contents of the objects.

  (51) The above (50), 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 branched from the norbornene-based polymer. 2. An optical waveguide structure according to 1.

  (52) The optical waveguide structure according to (50) or (51), wherein the norbornene-based polymer includes a repeating unit of aralkyl norbornene.

  (53) The optical waveguide structure according to (50) or (51), wherein the norbornene-based polymer includes a repeating unit of benzylnorbornene.

  (54) The optical waveguide structure according to (50) or (51), wherein the norbornene-based polymer includes a repeating unit of phenylethylnorbornene.

(55) the norbornene-based polymer has 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 separated from the main chain;
The core part and the clad part are different in the number of leaving groups bonded to the main chain, and the content of a reaction product of a norbornene monomer having a refractive index different from that of the norbornene polymer. The optical waveguide structure according to any one of (50) to (54), wherein the refractive indexes thereof are different due to being different.

(56) The core layer is composed of, as a main material, a norbornene polymer having a main chain and a branching group that is branched from the main chain and at least a part of the molecular structure of which can be detached from the main chain.
The first norbornene-based material and the second norbornene-based material are different from each other in refractive index due to a difference in the number of the leaving groups bonded to the main chain. Optical waveguide structure.

  (57) The optical waveguide structure according to (55) or (56), wherein the norbornene-based polymer includes a repeating unit of diphenylmethylnorbornenemethoxysilane.

  (58) The optical waveguide structure according to any one of (50) to (57), wherein the norbornene-based polymer includes an alkylnorbornene repeating unit.

  (59) The optical waveguide structure according to any one of (50) to (57), wherein the norbornene-based polymer includes a repeating unit of hexyl norbornene.

  (60) The optical waveguide structure according to any one of (50) to (59), wherein the norbornene-based polymer is an addition polymer.

  (61) The optical waveguide structure according to any one of (21) to (60), 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.

  (62) The optical waveguide structure according to (61), wherein the cladding layer is configured using a norbornene-based polymer as a main material.

  (63) The optical waveguide structure according to (62), wherein the norbornene-based polymer is an addition polymer.

  (64) The optical waveguide structure according to (62) or (63), wherein the norbornene-based polymer includes an alkylnorbornene repeating unit.

  (65) The optical waveguide structure according to any one of (62) to (64), wherein the norbornene-based polymer includes a norbornene repeating unit having a substituent containing a polymerizable group.

  (66) The norbornene repeating unit having a substituent containing a polymerizable group is a norbornene repeating unit having a substituent containing an epoxy group, a norbornene repeating unit having a substituent containing a (meth) acryl group, and The optical waveguide structure according to (65), wherein the optical waveguide structure is at least one of repeating units of norbornene having a substituent containing an alkoxysilyl group.

  (67) The optical waveguide structure according to (65) or (66), wherein at least a part of the norbornene-based polymer is crosslinked at a polymerizable group.

  (68) The optical waveguide structure according to any one of (62) to (64), wherein the norbornene-based polymer includes a norbornene repeating unit having a substituent containing an aryl group.

  (69) The optical waveguide structure according to (68), wherein at least a part of the norbornene-based polymer is crosslinked via a crosslinking agent.

  (70) The optical waveguide structure according to any one of (62) to (69), wherein an average of the cladding layer is 0.1 to 1.5 times an average thickness of the core layer.

  According to the present invention, the core part is three-dimensionally arranged, and the patterning of the core part can be performed by a simple method of irradiation with active radiation (active energy ray, electron beam, X-ray, etc.). Therefore, a core part having a wide degree of freedom in designing the pattern shape of the core part, that is, the arrangement of the optical path, and high dimensional accuracy can be obtained.

  In addition, when the core layer is made of a desired material, even if stress is applied to the optical waveguide body or deformation occurs, delamination between the core and cladding and microcracks occur in the core. 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 norbornene-based resin, the effect of being particularly strong against the deformation and being difficult to cause defects is high, and the difference in refractive index between the core part and the cladding part is increased. The optical waveguide can be made larger, and has excellent heat resistance, and as a result, an optical waveguide with higher performance and durability can be obtained.

  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, and a small and integrated optical circuit can be formed.

  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).

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

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

  FIG. 1 is a perspective view showing a first embodiment of the optical waveguide structure of the present invention, and FIG. 2 is an arrangement (pattern) of the core portion of the first core layer in the optical waveguide structure shown in FIG. FIG. 3 is a diagram showing the arrangement (pattern) of the core portion of the second-stage core layer in the optical waveguide structure shown in FIG. 1, and FIG. 4 is the three-stage in the optical waveguide structure shown in FIG. It is a figure which shows arrangement | positioning (pattern) of the core part of the core layer of an eye. Hereinafter, a configuration example of the optical waveguide structure will be described with reference to these drawings.

  In the following description, directions of X, Y, and Z (X, Y, and Z are directions orthogonal to each other) shown in FIG. 1 are respectively referred to as “X direction”, “Y direction”, and “Z direction”. The directions opposite to the X direction, Y direction, and Z direction are referred to as “−X direction”, “−Y direction”, and “−Z direction”, respectively. Further, the upper part in FIG. 1 of the optical waveguide structure is referred to as “upper” or “upper stage”, the lower part is referred to as “lower” or “lower stage”, and an intermediate portion between the upper stage and the lower stage is referred to as “middle stage”. In addition, the upper surface of the optical waveguide body in FIG. 1 (FIG. 8) is the “upper surface”, the lower surface is the “lower surface”, the right surface is the “right surface”, the front surface is the “front surface”, and the back surface. The side surface is called the “back”.

<First Embodiment: FIG. 1>
As shown in FIG. 1, the optical waveguide structure 1 of the present invention includes a block-shaped optical waveguide body 2 and five light emitting elements 61, 62, 63, 64 and 65.

  The light emitting elements 61, 62, 63, 64, and 65 have light emitting portions 610, 620, 630, 640, and 650, respectively, and a pair of terminals (not shown). For example, when a current is applied (given a potential difference) between the terminals of the light emitting element 61, the light emitting unit 610 is turned on (emits light). The same applies to the other light emitting elements 62 to 65.

  Each of the light emitting portions 610 to 650 of the light emitting elements 61 to 65 may be configured by one light emitting point, or may be a set 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 in a light receiving element to be described later.

  The light emitting elements 61 to 65 are bonded to the surface of the optical waveguide body 2 such that the light emitting portions 610 to 650 are in contact with or face the surface of the optical waveguide body 2. However, in the present invention, all or a part of each of the light emitting elements 61 to 65 may be installed (embedded) inside the optical waveguide body 2. The same applies to the case where a light receiving element is installed together with the light emitting elements 61 to 65 or instead of the light emitting elements 61 to 65.

  Each of the light emitting elements 61 to 65 operates (emits light) independently, but any two or more of them emit light in conjunction (particularly simultaneously) or emit light synchronously. You may do it. The light emission pattern of each light emitting element 61-65 can be set arbitrarily, and the light emission pattern may change with time.

  The optical waveguide body 2 is formed by laminating a clad layer 91 and a core layer 93 in a predetermined order. In this case, the optical waveguide body 2 includes a plurality of cladding layers 91 and a plurality of core layers 93 (three steps in the Z direction).

  Each core layer 93 has a core portion 94 and a clad portion 95 having a predetermined pattern (see FIGS. 1 to 4). The core portion 94 is a portion that forms an optical path of the transmission light, and the cladding portion 95 is a portion that is formed in the core layer 93 but does not form an optical path of the transmission light and performs the same function as the cladding layer 91. is there.

  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 layer 91. The clad portion 95 exists on both sides of the core portion 94, and the clad portion 95 or the clad layer 91 exists below and above the core portion 94. With such a configuration, the core portion 94 functions as a light guide path (optical waveguide) surrounded by the clad portion on the entire outer periphery.

  As shown in FIG. 1, the core portion 94 is three-dimensionally arranged in the optical waveguide body 2. That is, the core portion 4 preferably has a portion extending in at least one of the X (-X), Y (-Y), and Z (-Z) directions, and X (-X ), Y (-Y) and Z (-Z) directions, and more preferably has a portion extending in at least two directions.

  The clad layer 91 transmits the transmitted light with a relatively high transmittance when the transmitted light is incident on the clad layer 91 in the layer thickness direction (direction perpendicular to the clad layer).

  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 layer 91 or the other core layer 93) 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 is maintained, and an optical waveguide excellent in durability can be 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 the 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 layer 91.

  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, a deformed shape, a shape having a branching portion of a light path, a merging portion or a crossing portion, a light collecting portion (width etc. are 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.

  Hereinafter, the arrangement (pattern) of the core portion 94 in each core layer in the optical waveguide body 2 will be specifically described.

<First (upper) core layer>
As shown in FIG. 2, three core portions 94 having a longitudinal shape extending in the Y direction are spaced apart from each other in the X direction by a core layer 93 in the first stage (upper stage) from the top in the optical waveguide body 2. And formed (arranged) substantially in parallel.

  2, one end of the core portion 94 in the left column is exposed on the back surface of the optical waveguide body 2, and the exposed surface constitutes the output end 942 of the transmission light 711. An optical path conversion unit (light emitting unit side optical path conversion unit) 4 a that bends the optical path of the core unit 94 is provided at the end of the core unit 94 opposite to the emission end 942.

  The optical path conversion unit 4a includes a reflection surface (mirror) 5a that reflects at least a part of the transmission light. The same applies to reflecting surfaces 5b, 5c, 5d and 5e described later.

  The reflecting surface 5a is inclined by approximately 45 ° with respect to the longitudinal direction of the core portion 94, reflects a part of the transmitted light 71 (for example, 50% of the light amount), and transmits the remaining part of the beam splitter (half mirror or dichroic mirror). The transmission light 71 emitted from the light emitting unit 610 is divided into a plurality of directions (two directions orthogonal to each other). Then, by setting the reflectance (transmittance) of the reflecting surface 5a, the light amounts of the divided transmission lights 711 and 712 can be set to a predetermined ratio. As a typical example, the light amounts of the transmission lights 711 and 712 can be made substantially equal.

  In the optical path conversion unit 4a, for example, a part (end part) of the core part 94 is obliquely cut (removed) to form an inclined surface, and the inclined surface can be used as the reflecting surface 5a. The reflecting surface 5a 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 changing portion 4a may be filled or joined with a filler, particularly a filler having a refractive index different from that of the core portion 94. The same applies to reflective surfaces 5b, 5c, 5d and 5e described later.

  The core portions 94 in the right column in FIG. 2 are continuously formed from the back surface to the front surface of the optical waveguide body 2, and the light emitting element 640 faces the exposed surface of the core portion 94 on the back surface. 64, and the exposed surface of the core portion 94 to the front surface constitutes an output end 943 of the transmission light 741. Moreover, the core part 94 of the right row in FIG. 2 branches in the branch part 941 in the middle, and forms the core part 94 of the center row | line | column in FIG. The core portion 94 is exposed on the front surface of the optical waveguide body 2, and the exposed surface constitutes an output end 944 of the transmission light 742.

  In the branching unit 941, the transmission light 74 emitted from the light emitting unit 640 is separated into transmission light 741 and 742. The ratio of the light amounts of the transmission light 741 and the transmission light 742 is not particularly limited, and can be, for example, about 1: 9 to 9: 1. Instead of the branching portion 941, a reflection surface (beam splitter: half mirror or dichroic mirror) similar to the reflection surface 5a may be provided to branch (divide) the optical path in a plurality of directions.

  Moreover, you may have the confluence | merging part of the structure similar to the branch part 941. FIG. In this case, in the illustrated branching portion 941, the direction of the transmitted light is opposite, and the two core portions (optical paths) are merged into one core portion (optical path).

<Second (middle) core layer>
As shown in FIG. 3, one long core portion 94 extending in the X direction is formed (arranged) on the second (middle) core layer 93 from the top in the optical waveguide body 2. One end of the core portion 94 is exposed on the right side surface of the optical waveguide body 2, and the exposed surface constitutes an output end 945 of the transmission light 72. An optical path conversion section (light emitting section side optical path conversion section) 4b that bends the optical path of the core section 94 is provided at the end of the core section 94 opposite to the emission end 945.

  The optical path conversion unit 4b includes a reflection surface (mirror) 5b that reflects at least a part of the transmission light. The reflecting surface 5b is inclined by approximately 45 ° with respect to the longitudinal direction of the core portion 94, and constitutes a total reflection mirror that reflects almost all of the transmitted light 72 (for example, 90% or more of the light amount).

<Third (lower) core layer>
As shown in FIG. 4, in the core layer 93 at the third level (lower level) from the top in the optical waveguide body 2, three longitudinal core portions 94 extending in the Y direction have a predetermined interval in the X direction. And formed (arranged) substantially in parallel.

  One end of the core portion 94 in the left column in FIG. 4 is exposed on the back surface of the optical waveguide body 2, and the exposed surface constitutes an output end 946 of the transmission light 712. An optical path conversion section (light emitting section side optical path conversion section) 4 c that bends the optical path of the core section 94 is provided at the end of the core section 94 opposite to the emission end 946.

  The optical path conversion unit 4c is configured by a reflective surface (mirror) 5c that reflects at least a part of the transmitted light. The reflection surface 5c is inclined by approximately 45 ° with respect to the longitudinal direction of the core portion 94, and reflects the entire transmission light 712 (for example, 90% or more of the amount of light) transmitted through the reflection surface 5a located above. Is configured.

  One end of the core portion 94 in the center row in FIG. 4 is exposed on the front surface of the optical waveguide body 2, and the exposed surface constitutes the emission end 947 of the transmission light 73. An optical path conversion unit (light emitting unit side optical path conversion unit) 4d that bends the optical path of the core unit 94 is provided at the end of the core unit 94 opposite to the emission end 947.

  The optical path conversion unit 4d is configured by a reflecting surface (mirror) 5d that reflects at least a part of the transmitted light. The reflecting surface 5d is inclined by approximately 45 ° with respect to the longitudinal direction of the core portion 94, and constitutes a total reflection mirror that reflects almost all of the transmitted light 73 (for example, 90% or more of the light amount).

  One end of each core portion 94 in the right column in FIG. 4 is exposed on the front surface of the optical waveguide body 2, and the exposed surface constitutes an output end 948 of the transmission light 73. The core portion 94 is bent in an L shape in the X direction in the middle, and an end portion thereof (an end portion opposite to the emission end 948) is exposed on the right side surface of the optical waveguide body 2. On the exposed surface, the light emitting element 65 is installed so that the light emitting unit 650 faces. The bent portion of the core portion 94 is provided with an optical path changing portion (light emitting portion side optical path changing portion) 4e for bending the optical path of the core portion 94.

  The optical path conversion unit 4e includes a reflection surface (mirror) 5e that reflects at least a part of the transmission light. The reflection surface 5e is inclined by approximately 45 ° with respect to the longitudinal direction of the core portion 94, and constitutes a total reflection mirror that reflects almost all of the transmitted light 75 (for example, 90% or more of the light amount).

  As shown in FIG. 1, light emitting elements 61, 62, and 63 are installed at predetermined positions on the upper surface of the optical waveguide body 2 so that the light emitting portions 610, 620, and 630 face each other.

  The light emitting element 61 is installed at a position where the reflecting surface 5a of the optical path changing unit 4a is located directly below the light emitting unit 610. Further, the reflection surface 5c of the optical path conversion unit 4c is located directly below the reflection surface 5a. In other words, when viewed in the Z direction, the light emitting unit 610, the reflective surface 5a, and the reflective surface 5c coincide.

  In addition, the light emitting element 62 is installed at a position where the reflecting surface 5b of the optical path changing unit 4b is located directly below the light emitting unit 620. That is, when viewed in the Z direction, the light emitting unit 620 and the reflecting surface 5b coincide. In this case, the core portion 94 (see FIG. 2) of the first-stage core layer 93 does not exist immediately below the light emitting portion 620. That is, the transmission light 72 emitted from the light emitting unit 620 does not intersect the core part 94 of the first-stage core layer 93 (transmits through the clad part 95 of the first-stage core layer 93) and is a reflective surface. 5b is reached so that crosstalk is prevented.

  The light emitting element 63 is installed at a position where the reflecting surface 5d of the optical path changing unit 4d is located directly below the light emitting unit 630. That is, when viewed in the Z direction, the light emitting unit 630 and the reflecting surface 5d are coincident with each other. In this case, the core portion 94 (see FIG. 2) of the first-stage core layer 93 and the core portion 94 (see FIG. 3) of the second-stage core layer 93 are not present immediately below the light emitting portion 630. That is, the transmission light 73 emitted from the light emitting unit 630 does not intersect the core part 94 of the first-stage core layer 93 (transmits through the cladding part 95 of the first-stage core layer 93), and further 2 It does not intersect with the core portion 94 of the core layer 93 at the stage (transmits through the clad portion 95 of the core layer 93 at the second stage) and reaches the reflection surface 5d. Is prevented.

  Further, the light emitting element 65 is installed at a position where the light emitting unit 650 and the reflection surface 5e of the optical path changing unit 4e coincide when viewed in the X direction.

  Although not shown, a light receiving element may be provided at a part or all of the emission ends 942, 943, 944, 945, 946, 947, 948. The light receiving element includes a light receiving unit and a terminal that photoelectrically converts light received by the light receiving unit and outputs an electrical signal. When transmission light emitted from the emission ends 942 to 948 is received by the light receiving portion of the light receiving element, an electronic signal is output from the terminal of the light receiving element.

  Next, configuration examples of the core layer and the clad layer constituting the optical waveguide body 2 will be described with reference to FIGS.

  In the configuration shown in FIG. 5, the clad layers 91 and the core layers 93 are alternately stacked. Each core layer 93 includes a core portion 94 and a clad portion 95 having a predetermined pattern.

  In the configuration shown in FIG. 6, a laminate having a three-layer structure in which the clad layers 91 are bonded to both surfaces of one core layer 93 (in other words, the core layer 93 is interposed between the two clad layers 91). (Optical waveguide) 90 is one unit, and two or more of the laminates 90 are stacked. The core layer 93 in each stacked body 90 includes a core portion 94 and a clad portion 95 having a predetermined pattern.

  The configuration shown in FIG. 7 includes a core layer stacking portion 92 in which a plurality of core layers 93 are stacked (in the illustrated case, four layers are stacked). Cladding layers 91 are bonded to the upper surface and the lower surface of the core layer stack portion 92, respectively.

  Each core layer 93 constituting the core layer laminated portion 92 includes a core portion 94 and a clad portion 95 having a predetermined pattern. In this case, the core layer 93 located at the uppermost part in FIG. 7 and the core layer 93 located at the lowermost part are respectively provided with optical path changing parts 4f and 4g composed of reflecting surfaces 5f and 5g. The two core layers 93 are provided with core portions 94 respectively. Thereby, the transmission light 76 transmitted in the Y direction through the core portion 94 of the core layer 93 positioned at the top in FIG. 7 is reflected by the reflecting surface 5f and bent at a right angle downward (Z direction). The core portion 94 formed in the two core layers 93 in the middle proceeds in the Z direction, is reflected by the reflecting surface 5g and bent at a right angle again, and the core portion 94 of the core layer 93 located at the bottom in FIG. Proceed in the Y direction.

  The optical waveguide body 2 in the present invention has at least one of the configurations shown in FIGS. Moreover, you may have 2 or more or all of the structures shown in FIGS.

  The constituent materials of the core layer 93 and the cladding layer 91, the method of forming the core portion 94, and the like will be described in detail later.

  The optical waveguide structure 1 of the present invention preferably has a conductor layer (not shown) on the surface and / or inside of the optical waveguide body 2. The conductor layer is preferably patterned into a predetermined shape to form a desired wiring (circuit). Such a conductor layer is preferably electrically connected to the terminals of the light emitting elements 61 to 65 and constitutes a current-carrying wiring to the light emitting elements 61 to 65. In the case where the light receiving element is installed, the conductor layer is preferably electrically connected to a terminal (output terminal) of the light receiving element and used as a circuit for detecting an output signal from the terminal.

  Such a conductor layer can also be arranged three-dimensionally on the surface and / or inside of the optical waveguide body 2. That is, the wiring in the conductor layer can be installed so as to extend in two or three directions of the X, Y, and Z directions, for example.

  Examples of the constituent material of the conductor layer include various metal materials such as copper, copper-based alloy, aluminum, and aluminum-based alloy. Although the thickness of a conductor layer is not specifically limited, Usually, about 3-120 micrometers is preferable and about 5-70 micrometers is more preferable.

  Moreover, it is preferable that a conductor layer is 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 layer.

  Next, the operation of the optical waveguide structure 1 shown in FIGS. 1 to 4 will be described. When the terminal of the light emitting element 61 is energized, the light emitting portion 610 is turned on, and the transmitted light 71 emitted in the Z direction is transmitted through the cladding portion (cladding layer 91 and cladding portion 95) and reflected on the reflecting surface 5a. It is separated into reflected light and transmitted light (see FIG. 1). The transmitted light (reflected light) 711 reflected by the reflecting surface 5a and bent by approximately 90 ° enters the core portion 94 of the first-stage core layer 93, proceeds in the −Y direction, and reaches the emission end 942 (FIG. 2). reference). The transmitted light (transmitted light) 712 that has passed through the reflecting surface 5 a and traveled in the Z direction is reflected (substantially totally reflected) by the reflecting surface 5 c and bent by approximately 90 °, and the core portion 94 of the third-stage core layer 93. And proceed in the −Y direction to reach the exit end 946 (see FIG. 4).

  When the terminal of the light emitting element 62 is energized, the light emitting portion 620 is turned on, and the transmitted light 72 emitted in the Z direction is transmitted through the cladding portion (the cladding layer 91 and the cladding portion 95) and reflected by the reflecting surface 5b. The light is reflected (substantially total reflection) and bent by approximately 90 °, enters the core portion 94 of the second-stage core layer 93, proceeds in the X direction, and reaches the emission end 945 (see FIGS. 1 and 3).

  When the terminal of the light emitting element 63 is energized, the light emitting portion 630 is turned on, and the transmitted light 73 emitted in the Z direction is transmitted through the clad portion (the clad layer 91 and the clad portion 95) and reflected by the reflecting surface 5d. The light is reflected (substantially total reflection) and bent by approximately 90 °, enters the core portion 94 of the third-stage core layer 93, proceeds in the Y direction, and reaches the emission end 947 (see FIGS. 1 and 4).

  When the terminal of the light emitting element 64 is energized, the light emitting section 640 is turned on, and the transmitted light 74 emitted in the Y direction enters the core section 94 of the second-stage core layer 93 and proceeds in the Y direction. In the section 941, the transmission light 741 and the transmission light 742 are separated. The transmitted light 741 and 742 respectively travel in the core portion 94 on the Y direction side from the branch portion 941 and reach the emission ends 943 and 944 (see FIGS. 1 and 2).

  When the terminal of the light emitting element 65 is energized, the light emitting portion 650 is turned on, and the transmitted light 75 emitted toward the −X direction enters the core portion 94 of the third core layer 93 and proceeds in the −X direction. Then, the light is reflected (substantially totally reflected) by the reflecting surface 5e, bent by approximately 90 °, proceeds in the Y direction, and reaches the emission end 948 (see FIGS. 1 and 4).

  FIG. 8 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.

  The optical waveguide structure 1 of the present embodiment has an inclined surface 3 in which at least one surface of the optical waveguide body 2 is inclined. That is, as shown in FIG. 8, the front surface of the optical waveguide body 2 is a cross section (= XZ plane) of the core portion (core portion extending in the Y direction) 94 of the first and third core layers 3. In contrast, the inclined surface 3 is inclined at an angle of approximately 45 ° (θ = 45 °). As a result, the exposed surfaces (exposed end surfaces) 961, 962, 963, 964, and 965 of the core portion 94 exposed on the inclined surface 3 are also inclined surfaces having the same angle. These exposed surfaces 961, 962, 963, 964, and 965 can be used as reflecting surfaces (total reflection surfaces: reflectance of 90% or more). For example, a reflective film such as a multilayer optical thin film or a metal thin film (for example, an aluminum vapor deposition film) or a reflection increasing film can be provided on these exposed surfaces 961 to 965 as described above.

  With this configuration, the exposed surface 961 reflects the Z-direction transmission light 71 emitted from the light emitting unit 610 of the light emitting element 61 so as to be bent in the −Y direction, and the exposed surfaces 962, 963, 964. And 965 respectively reflect the transmission lights 742, 741, 73, and 75 traveling in the core portion 94 so as to bend in the −Z direction.

  In the present embodiment, since the exposed surface 961 is a reflection surface that substantially totally reflects, the left row of core portions 94 (corresponding to the left row of core portions 94 in FIG. 4) of the third-stage core layer 93 and the optical path. There is no conversion unit 4c.

  In addition, the inclination angle (angle formed with the XZ plane) θ of the inclined surface 3 is not limited to 45 °, and for example, θ can be about 20 to 70 °. Further, the exposed surfaces 961 to 965 are not limited to the total reflection surface, but may be ones having a function of separating the transmitted light into reflected light and transmitted light (beam splitter) such as a half mirror or a dichroic mirror. .

  Needless to say, the inclined surface 3 is not limited to the one formed for the purpose of bending the optical path by reflection or the like. Such an inclined surface may be formed on a surface other than the front surface of the optical waveguide body 2, or may be formed on two or more surfaces of the optical waveguide body 2.

  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 body (optical waveguide) 2 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, a first manufacturing method of the laminate 90 (hereinafter simply referred to as “optical waveguide”) in the optical waveguide body 2 will be described.

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

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

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

  When the layer 910 is formed by a coating method, 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 a polymer 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), a combination of ROMP and a hydrogenation reaction, polymerization by radicals or cations, 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 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, the optical waveguide is preferably used in data communication using light in a wavelength region of about 600 to 1550 nm, for example. This is preferable because the transmittance with respect to light in a wavelength region (particularly, a wavelength region near 850 nm) is excellent.

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

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

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

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

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

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

  When the refractive index of the irradiated region in the layer 910 decreases due to the 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, it is possible to obtain the core layer 93 (optical waveguide) that is excellent in optical transmission performance and excellent in heat resistance and flexibility.

  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 a halogen atom, that is, a halohydrocarbyl group, a perhalohydrocarbyl group. 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 forming (process) the core layer 93 (optical waveguide) 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).

一方、連結多環環系の化合物（連結多環環系の架橋性ノルボルネン系モノマー）としては、下記化８で表される化合物が挙げられる。

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

［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.

この化１０で表される化合物は、ジメチルビス［ビシクロ［２．２．１］へプト−２−エン−５−メトキシ］シランであり、またの命名では、ジメチルビス（ノルボルネンメトキシ）シラン（「ＳｉＸ」と略される。）と呼ばれる。

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) 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) can be formed by heat treatment at a relatively low temperature, and unnecessary heat is applied to other layers to prevent deterioration of the optical waveguide characteristics (optical transmission performance). can do.

  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 selected from integers of 1 and 2, respectively.

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) 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 applies below) 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. 9B).

  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.

  In FIG. 9B, an opening (window) 9351 equivalent to the pattern of the clad portion 95 to be formed is obtained by partially removing the mask along the pattern of the unirradiated 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. 9-C).

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

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

  When the configuration shown in FIG. 7 is manufactured, a plurality of core layers 93 are prepared by the above-described method, and the core layer stacking portion 92 is obtained by overlapping (bonding) these layers. In this case, the pattern of the core portion 94 in each core layer 93 can form a predesigned three-dimensional optical path pattern when the core layers 93 are laminated in a desired order.

  Further, the clad layer 91 described later is bonded (press-bonded) to the upper surface and the lower surface of the core layer laminated portion 92, whereby the configuration shown in FIG. 7 is completed. As another method, a plurality of core layers 93 may be sequentially laminated (bonded) to the lower clad layer 91 in FIG. 6, and finally the upper clad layer 91 in FIG. 6 may be bonded (crimped).

[6A] Next, the cladding layer 91 is formed on the support substrate 952 (see FIG. 9D).
The clad layer 91 can be formed by any method, such as a method of applying and curing (solidifying) a varnish containing a clad material (clad layer forming material), a method of applying and curing (solidifying) a monomer composition having curability. The method may be used.

When the clad layer 91 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.

  As a constituent material of the clad layer 91, for example, acrylic resin, methacrylic resin, polycarbonate, polystyrene, epoxy resin, polyamide, polyimide, polybenzoxazole, benzocyclobutene resin, cyclic olefin resin such as norbornene resin, etc. Among these, one or a combination of two or more thereof (polymer alloy, polymer blend (mixture), copolymer, composite (laminate), etc.) can be used.

  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 using this as a constituent material of the clad layer 91, when forming the conductor layer in the optical waveguide, when forming the wiring by processing the conductor layer, the optical element Even when heated for mounting, etc., it is possible to prevent the cladding layer 91 from being softened and deformed.

  Moreover, since it has high hydrophobicity, it is possible to obtain the clad layer 91 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.

  Further, when a material mainly composed of a norbornene-based polymer is used as the material of the clad layer 91, the clad layer 91, 91 and the core layer 93 are delaminated even when repeatedly bent and deformed. Is less likely to occur, and the occurrence of microcracks in the clad layer 91 is also prevented. In addition, since it is the same kind of material that is preferably 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 and the core layer 93 is prevented. be able to. For this reason, the optical transmission performance of the optical waveguide is maintained, and an optical waveguide with 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), a combination of ROMP and a hydrogenation reaction, polymerization by radicals or cations, 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, at least a part of the norbornene-based polymer in the cladding layer 91 can be crosslinked directly or via a crosslinking agent. . 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 itself and the adhesion between the clad layer 91 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 a dimensional change due to water absorption of the clad layer 91 can be more reliably prevented. In addition, since the aryl group is excellent in fat solubility (lipophilicity) and has a high affinity with the polymer used for the core layer 93 as described above, the delamination between the clad layer 91 and the core layer 93 is further improved. An optical waveguide that can be reliably prevented and is more durable is 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 cladding layers 91 and 91 (optical waveguide).

  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 is preferably a polymer having a relatively low refractive index. On the other hand, when it contains a norbornene repeating unit having a substituent containing an aryl group, the refractive index generally increases. Although it shows a tendency, an increase in the refractive index can be prevented by including a repeating unit of alkyl norbornene.

  Therefore, as the norbornene-based polymer used for the clad layer 91, 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. ]

  Of 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 one 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 using such a norbornene-based polymer as a main material, the optical transmission performance of the optical waveguide can be improved. It can be improved further.

  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 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, the refractive index of the clad layer 91 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 polymer in the clad layer 91 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, a catalyst precursor that can be easily activated by heating can be used by omitting the promoter.

Examples of such a catalyst precursor 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 is formed on the support substrate 952.

  The average thickness of the clad layer 91 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. Although the average thickness of the clad layer 91 is not particularly limited, it is usually preferably about 1 to 200 μm, more preferably about 5 to 100 μm, and about 10 to 60 μm. Further preferred. Thereby, the function as a clad layer is suitably exhibited while preventing the optical waveguide 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 divided into a support substrate 952 on which the cladding layer 91 is formed and a support substrate 952 on which the other cladding layer 91 is formed. (See FIG. 9-E).

9E, pressure is applied from the upper surface side of the support substrate 952 on which the upper clad layer 91 is formed, and the clad layers 91 and 91 and the core layer 93 are pressure-bonded.
Thereby, the clad layers 91 and 91 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 91 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 both clad layers 91, respectively. Thereby, an optical waveguide (laminated body 90) is obtained.

  When the structure shown in FIG. 6 is manufactured, a plurality of optical waveguides (laminated body 90) are prepared by the method described above, and these are overlapped and bonded (crimped). In this case, the pattern of the core portion 94 in the core layer 93 of each stacked body 90 can form a predesigned three-dimensional optical path pattern when the stacked bodies 90 are stacked in a desired order. .

  Moreover, when manufacturing the structure shown in FIG. 5, the following three methods are possible, for example. First, as a first method, there is a method in which one optical waveguide (laminated body 90) is produced, a core layer 93 and a clad layer 91 are repeatedly laminated in this order, and these are pressure-bonded. As a second method, there is a method in which two optical waveguides (laminated body 90) are produced, a core layer 93 is interposed between the optical waveguides (laminated body 90), and these are crimped and integrated. As a third method, there is a method in which a plurality of two-layer laminates in which the clad layer 91 and the core layer 93 are laminated are produced, and the respective two-layer laminates are laminated in a desired order, followed by pressure bonding. As a fourth method, there is a method in which each of the clad layer 91 and the core layer 93 is produced one by one, these are laminated in a desired order, and pressure-bonded.

  In the first to fourth methods, the pattern of the core portion 94 in each core layer 93 is the optical path pattern in a three-dimensional direction designed in advance when the clad layers 91 and the core layers 91 are laminated in a desired order. It can be formed.

  In a preferable example of such an optical waveguide, in the core layer 93, the core portion 94 is configured by using the first norbornene-based material as a main material, and the cladding portion 95 has a lower refractive index than that of the first norbornene-based material. The main material is a norbornene-based material, and both clad layers 91 are each composed 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 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, high optical transmission performance can be obtained in the optical waveguide body 2 having such an optical waveguide.

  In addition, 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 and both the clad layers 91 can be obtained, and the optical waveguide can be bent. Even when this deformation occurs, peeling between the core portion 94 and the clad portion 95 and delamination between the core layer 93 and the clad layer 91 hardly occur, and microcracks are generated in the core portion 94 and the clad portion 95. This is also prevented. As a result, the optical transmission performance of the optical waveguide is maintained.

  Furthermore, since norbornene-based polymers have high heat resistance and high hydrophobicity, the optical waveguide having such a configuration has excellent durability.

  In addition, since high heat resistance and high hydrophobicity can be imparted to the optical waveguide, the conductor layer can be reliably formed by adopting various methods as described above while preventing deterioration (deterioration) of the characteristics. be able to. 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, an optical waveguide having a 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 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 the main chain.
As the release 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 is completed as described above.

  In a preferred example of such an optical waveguide, the core layer 93 is composed of a norbornene-based material as a main material, and both clad layers 91 are each composed of a norbornene-based polymer having a refractive index lower than that of the core portion 94 of the core layer 93. Configured as

  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, high optical transmission performance can be obtained in the optical waveguide having such a configuration.

  In addition, 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 and both the clad layers 91 can be obtained, and the optical waveguide can be bent. Even when this deformation occurs, peeling between the core portion 94 and the clad portion 95 and delamination between the core layer 93 and the clad layer 91 hardly occur, and microcracks are generated in the core portion 94 and the clad portion 95. This is also prevented. As a result, the optical transmission performance of the optical waveguide is maintained.

  Furthermore, since norbornene-based polymers have high heat resistance and high hydrophobicity, the optical waveguide having such a configuration has excellent durability.

  In addition, since high heat resistance and high hydrophobicity can be imparted to the optical waveguide, the conductor layer can be reliably formed by adopting various methods as described above while preventing deterioration (deterioration) of the characteristics. be able to. 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, an optical waveguide having a 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 an optical waveguide 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 is completed as described above.

  In a preferred example of such an optical waveguide, the core layer 93 contains 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 reactant of a norbornene monomer having a refractive index different from that of the norbornene polymer. By being different, their refractive indexes are different, and both clad layers 91 are mainly composed of a norbornene polymer having a refractive index lower than that of the core portion 94 of the core layer 93.

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

  In addition, 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 and both the clad layers 91 can be obtained, and the optical waveguide can be bent. Even when this deformation occurs, peeling between the core portion 94 and the clad portion 95 and delamination between the core layer 93 and the clad layer 91 hardly occur, and microcracks are generated in the core portion 94 and the clad portion 95. This is also prevented. As a result, the optical transmission performance of the optical waveguide is maintained.

  Furthermore, since norbornene-based polymers have high heat resistance and high hydrophobicity, the optical waveguide having such a configuration has excellent durability.

  In addition, since high heat resistance and high hydrophobicity can be imparted to the optical waveguide, the conductor layer can be reliably formed by adopting various methods as described above while preventing deterioration (deterioration) of the characteristics. be able to. 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, an optical waveguide having a 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 an optical waveguide is demonstrated.

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

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

  In the fourth manufacturing method, the 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. 10A). reference).
As the support substrate 1000, a substrate similar to the support substrate 951 can be used.

  The average thickness of the first layer 1110 is not particularly limited, but is preferably about 5 to 200 μm, more preferably about 10 to 100 μm, and still more preferably about 15 to 65 μm.

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

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

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

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

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

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

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

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

[4D] Next, the solvent in the laminate 2000 is removed (desolvent).
Examples of the method for removing the solvent include methods such as heating, leaving under atmospheric pressure or reduced pressure, and spraying (blowing) an inert gas, etc., but a method using heating is preferred. 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. 10-D). .

  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. 10-E).

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

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

[8D] Next, the stacked body 2000 is subjected to a third heat treatment.
Thereby, the internal stress generated in the obtained core layer 93 can be reduced, and the core portion 94 and the cladding portion 95 can be further stabilized.
An optical waveguide 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 layer 91 and the core layer 93 can be more reliably prevented.

  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.

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

  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 promoters include non-absorbing photobase generators (PBG) and thermal base generators (TBG).

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

  In each of the above embodiments, the configuration including the light emitting elements 61 to 65 as the element has been described. However, the configuration may include one or more light receiving elements, or one or more light emitting elements and one or more. The light receiving element may be provided. Of course, the structure which has two or more sets of a light emitting element and a light receiving element may be sufficient.

  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 a perspective view which shows 1st Embodiment of the optical waveguide structure of this invention. It is a figure which shows arrangement | positioning of the core part of the 1st step | paragraph core layer in the optical waveguide structure shown in FIG. It is a figure which shows arrangement | positioning of the core part of the 2nd step | paragraph core layer in the optical waveguide structure shown in FIG. It is a figure which shows arrangement | positioning of the core part of the 3rd step | paragraph core layer in the optical waveguide structure shown in FIG. It is sectional drawing which shows the example of the layer structure of an optical waveguide main body. It is sectional drawing which shows the example of the layer structure of an optical waveguide main body. It is sectional drawing which shows the example of the layer structure of an optical waveguide main body. It is a perspective view which shows 2nd Embodiment of the optical waveguide structure of this invention. It is sectional drawing which shows typically the process example of the 1st manufacturing method of 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 Optical waveguide main body 3 Inclined surface 4a, 4b, 4c, 4d, 4e, 4f, 4g Optical path conversion part 5a, 5b, 5c, 5d, 5e, 5f, 5g Reflecting surface 61, 62, 63, 64 , 65 Light emitting element 610, 620, 630, 640, 650 Light emitting part 71, 711, 712 Transmitted light 72 Transmitted light 73 Transmitted light 74, 741, 742 Transmitted light 75 Transmitted light 76 Transmitted light 90 Laminate (optical waveguide)
91 Cladding layer 92 Core layer laminated part 93 Core layer 94 Core part 941 Branch part 942, 943, 944, 945, 946, 947, 948 Outgoing end 95 Cladding part 961, 962, 963, 964, 965 Exposed surface (exposed end surface)
900 Core layer forming material 910 layer 915 polymer 920 additive 925 irradiated region 930 actinic radiation 935 mask 9351 opening 940 unirradiated region 951, 952 supporting substrate 1000 supporting substrate 1110 first layer 1120 second layer 1130 third layer 2000 Laminate

Claims (70)

An optical waveguide body having a core part forming an optical path and a clad part formed on an outer periphery of the core part and having a refractive index different from the core part;
The core portion is three-dimensionally arranged in the optical waveguide body,
The core part is formed into a desired shape by selectively irradiating the active radiation to a core layer made of a material whose refractive index changes by irradiation with active radiation or by further heating. An optical waveguide structure characterized in that   2. The optical waveguide structure according to claim 1, wherein the core portion has a portion extending in at least one of X, Y, and Z directions orthogonal to each other.   2. The optical waveguide structure according to claim 1, wherein the core portion has a portion extending in at least two directions of X, Y, and Z directions orthogonal to each other.   4. The optical waveguide structure according to claim 1, wherein the optical waveguide body has a portion in which a clad layer and a core layer constituting the clad portion are alternately laminated.   5. The optical waveguide according to claim 1, wherein the optical waveguide body has a portion in which two or more laminated bodies each formed by joining the clad layers constituting the clad portion are overlapped on both surfaces of the core layer. Structure.   The optical waveguide structure according to any one of claims 1 to 5, wherein the optical waveguide main body includes a core layer laminated portion in which a plurality of the core layers are laminated.   The optical waveguide structure according to any one of claims 4 to 6, further comprising a portion configured to transmit and receive transmission light between the core portions formed between different core layers.   The optical waveguide structure according to any one of claims 1 to 7, 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 8, wherein the optical path conversion unit has a reflection surface that reflects at least a part of the transmission light.   The optical waveguide structure according to claim 8 or 9, wherein the optical path conversion unit has a function of dividing an optical path of the transmission light in a plurality of directions.   The core part is arranged so that transmission light incident on a predetermined part of the core part from the outside of the optical waveguide body does not intersect with other parts of the core part. The optical waveguide structure described.   The optical waveguide structure according to claim 1, wherein the core portion has a portion where an optical path branches and / or merges.   When transmission light is incident on a predetermined part of the core part from one incident direction of X, Y, and Z directions orthogonal to each other, the transmission light is orthogonal to the incident direction from other parts of the core part The optical waveguide structure according to any one of claims 1 to 12, wherein the optical waveguide structure is configured to emit light to a light source.   14. The optical waveguide structure according to claim 1, wherein at least one surface of the optical waveguide body is configured by an inclined surface inclined with respect to a transverse section of the core portion.   The optical waveguide structure according to any one of claims 1 to 14, comprising at least one element having a light emitting part or a light receiving part and a terminal.   The optical waveguide structure according to claim 1, wherein the element is bonded to a surface of the optical waveguide main body.   16. The optical waveguide structure according to claim 1, wherein at least a part of the element is installed inside the optical waveguide body.   18. The optical waveguide structure according to claim 15, comprising two or more elements that operate independently of each other, operate in conjunction with each other, or operate synchronously.   The optical waveguide structure according to claim 1, comprising a conductor layer.   The optical waveguide structure according to claim 15, further comprising a conductor layer, wherein the terminal is electrically connected to the conductor layer. The core layer may initiate a reaction of the monomer with a polymer, a monomer that is compatible with the polymer and has a refractive index different from that of the polymer, and a first substance that is activated by irradiation with actinic radiation. Forming a layer containing a second substance, the second substance having an activation temperature changed by the action of the activated first substance;
Thereafter, the first substance is activated in the irradiation region irradiated with the actinic radiation by selectively irradiating the layer with the actinic radiation, and the activation temperature of the second substance. Change
Next, by applying heat treatment to the layer, the lower one of the second substance or the second substance whose activation temperature is changed is activated, and the irradiation region or the Either one of the irradiated region and the unirradiated region is caused by reacting the monomer in any of the unirradiated regions of actinic radiation to generate a refractive index difference between the irradiated region and the unirradiated region. 21. The optical waveguide structure according to claim 1, wherein the core portion is obtained as the core portion and the other is obtained as the clad portion.   The core layer is obtained by collecting the unreacted monomer from the other region as the reaction of the monomer proceeds in either the irradiated region or the unirradiated region of the layer. The optical waveguide structure according to claim 21.   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. 23. The optical waveguide structure according to claim 21 or 22, wherein:   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 any one of claims 21 to 23. The optical waveguide structure according to claim 24, 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 24 or 25, wherein the second substance contains 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. ]   27. The optical waveguide structure according to claim 26, wherein p and r are each selected from an integer of 1 or 2.   28. The light beam according to claim 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.   29. The core layer according to claim 28, 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.   30. The optical waveguide structure according to claim 29, wherein the third temperature is 20 [deg.] C. or more higher than the second temperature.   The optical waveguide structure according to any one of claims 21 to 30, wherein the monomer includes a crosslinkable monomer.   32. The optical waveguide structure according to claim 21, wherein the monomer is mainly a norbornene-based monomer.   32. The optical waveguide structure according to claim 31, wherein the monomer is mainly a norbornene-based monomer and includes dimethylbis (norbornenemethoxy) silane as the crosslinkable monomer.   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. In particular, the optical waveguide structure according to any one of claims 21 to 33, wherein the leaving group of the polymer is released in the irradiated region.   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. 35. An optical waveguide structure according to claim 34. The core layer includes a substance that is activated by irradiation with actinic radiation, a main chain and a branch that is branched from the main chain, and at least part of the molecular structure can be detached from the main chain by the action of the activated substance. Forming a layer containing a polymer having a functional group,
Thereafter, by selectively irradiating the layer with the actinic radiation, the substance is activated in the irradiation region irradiated with the actinic radiation, and the leaving group of the polymer is released, By producing a refractive index difference between the irradiation region and the non-irradiation region of the active radiation, either the irradiation region or the non-irradiation region was obtained as the core portion, and the other was obtained as the cladding portion. 21. The optical waveguide structure according to claim 1, wherein the optical waveguide structure is one.   37. The optical waveguide structure according to claim 36, wherein the core layer is obtained by subjecting the layer to heat treatment after 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. The optical waveguide structure according to 36 or 37.   The optical waveguide structure according to claim 35 or 38, wherein the acid leaving group has at least one of an -O- structure, an -Si-aryl structure, and an -O-Si- structure.   40. The optical waveguide structure according to any one of claims 34 to 39, wherein the leaving group causes a decrease in the refractive index of the polymer due to the leaving.   41. The optical waveguide structure according to claim 40, wherein the leaving group is at least one of a -Si-diphenyl structure and a -O-Si-diphenyl structure.   The optical waveguide structure according to any one of claims 21 to 41, wherein the active radiation has a peak wavelength in a range of 200 to 450 nm. The dose of the actinic radiation is, the optical waveguide structure according to any one of claims 21 a 0.1~9J / cm ² 42.   44. The optical waveguide structure according to claim 21, wherein the active radiation is applied to the layer through a mask.   45. The optical waveguide structure according to any one of claims 21 to 44, wherein the layer further contains an antioxidant.   The optical waveguide structure according to any one of claims 21 to 45, wherein the layer further contains a sensitizer.   47. The optical waveguide structure according to claim 21, wherein the polymer is mainly a norbornene-based polymer.   48. The optical waveguide structure according to claim 47, wherein the norbornene-based polymer is an addition polymer.   The core portion is composed of a first norbornene-based material as a main material, and the cladding portion 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 20.   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. The optical waveguide structure according to claim 49, wherein the refractive indexes thereof are different due to different amounts.   51. The light according to claim 50, 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 optical waveguide structure according to claim 50 or 51, wherein the norbornene-based polymer includes a repeating unit of aralkylnorbornene.   52. The optical waveguide structure according to claim 50, wherein the norbornene-based polymer includes a repeating unit of benzylnorbornene.   52. The optical waveguide structure according to claim 50, wherein the norbornene-based polymer includes a repeating unit of phenylethyl norbornene. The norbornene-based polymer has a leaving group that is branched from a main chain and the main chain, and at least a part of the molecular structure can be removed from the main chain,
The core part and the clad part are different in the number of leaving groups bonded to the main chain, and the content of a reaction product of a norbornene monomer having a refractive index different from that of the norbornene polymer. 55. The optical waveguide structure according to any one of claims 50 to 54, wherein the refractive indexes thereof are different by being different. The core layer is 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 refractive index of the first norbornene-based material and the second norbornene-based material are different from each other in that the number of the leaving groups bonded to the main chain is different. Optical waveguide structure.   57. The optical waveguide structure according to claim 55 or 56, wherein the norbornene-based polymer includes a repeating unit of diphenylmethylnorbornene methoxysilane.   58. The optical waveguide structure according to any one of claims 50 to 57, wherein the norbornene-based polymer includes a repeating unit of alkyl norbornene.   58. The optical waveguide structure according to any one of claims 50 to 57, wherein the norbornene-based polymer includes a repeating unit of hexyl norbornene.   60. The optical waveguide structure according to claim 50, wherein the norbornene-based polymer is an addition polymer.   The optical waveguide structure according to any one of claims 21 to 60, 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.   62. The optical waveguide structure according to claim 61, wherein the cladding layer is composed of a norbornene-based polymer as a main material.   The optical waveguide structure according to claim 62, wherein the norbornene-based polymer is an addition polymer.   64. The optical waveguide structure according to claim 62 or 63, wherein the norbornene-based polymer includes a repeating unit of alkyl norbornene.   The optical waveguide structure according to any one of claims 62 to 64, wherein the norbornene-based polymer includes a norbornene repeating unit having a substituent containing a polymerizable group.   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 66. The optical waveguide structure according to claim 65, wherein the optical waveguide structure is at least one of repeating units of norbornene having a substituent containing.   The optical waveguide structure according to claim 65 or 66, wherein at least a part of the norbornene-based polymer is crosslinked at a polymerizable group.   The optical waveguide structure according to any one of claims 62 to 64, wherein the norbornene-based polymer includes a norbornene repeating unit having a substituent containing an aryl group.   69. The optical waveguide structure according to claim 68, wherein at least a part of the norbornene-based polymer is crosslinked through a crosslinking agent. 70. The optical waveguide structure according to claim 62, wherein an average of the cladding layer is 0.1 to 1.5 times an average thickness of the core layer.

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