JP4254745B2 - Optical waveguide and optical waveguide structure - Google Patents

Description

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

  In recent years, optical communications that transport data using optical frequency carriers have become increasingly important. In such optical communication, there is an optical waveguide as a means for guiding an optical frequency carrier wave from one point to another point.

  For example, the optical waveguide includes a pair of cladding layers and a core layer provided between the pair of cladding layers. The core layer has a linear core portion and a clad portion, which are alternately arranged. The core portion is made of a material that is substantially transparent to light of an optical frequency carrier wave, and the cladding layer and the cladding portion are made of a material having a lower refractive index than the core portion.

  In such an optical waveguide, the core portion is surrounded by a cladding layer and a cladding portion having a refractive index lower than that of the core portion. Therefore, the light introduced from the end portion of the core portion is conveyed along the axis of the core portion while being reflected at the boundary between the cladding layer and the cladding portion.

  Examples of the material for the optical waveguide include polymers, etc., in addition to conventionally used glass. Among these, polymers are promising because they are easy to finely process and are advantageous for increasing the density of circuit boards in which optical waveguides are incorporated.

  As a polymer used as a material for such an optical waveguide, polymethyl methacrylate (for example, see Patent Document 1), epoxy resin (for example, see Patent Document 2), and fluorinated polyimide (for example, see Patent Document 3). Polybenzoxazole (for example, see Patent Document 4), cellulose acetate butyrate / acrylate monomer (for example, see Patent Document 5), and the like are used.

However, these polymers have the following problems.
First, polymethylmethacrylate and epoxy resin have a heat resistant temperature of 200 ° C. or lower. For this reason, when it is going to mount the optical waveguide comprised by these polymers on a circuit board, there exists a possibility that it may soften by heat processing, such as a soldering process.

  Fluorinated polyimide is a polymer imparted with high heat resistance, high transparency, and low water absorption by fluorination. However, since fluorination is included in the synthesis process, it is expensive and lacks practicality.

  In addition, a polymer synthesized by polycondensation such as polyimide or polybenzoxazole requires a curing treatment at a high temperature (250 ° C. or higher) to close the imide ring or benzoxazole ring in the polycondensation step. For this reason, there exists a problem that workability | operativity is bad.

  In addition, the cellulose acetate acetate butyrate / acrylate monomer has an extremely low heat resistant temperature of 100 ° C. or less, and is softened by heat treatment such as soldering. Moreover, since cellulose acetate acetate butyrate has many hydroxyl groups, water absorption is high. For this reason, when an optical waveguide constituted by such a polymer is left in a high humidity environment, a dimensional change due to water absorption occurs.

Japanese Patent Application Laid-Open No. 09-258051 JP-A-2005-070556 Japanese Patent Laid-Open No. 4-9807 JP 2002-173532 A US Pat. No. 5,292,620

  An object of the present invention is to provide an optical waveguide and an optical waveguide structure that have excellent heat resistance, low water absorption, and low material cost.

［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。］ Such an object is achieved by the present inventions (1) to (46) below.
A core layer comprising a core portion and a cladding portion having a lower refractive index than the core portion;
An optical waveguide provided in contact with at least one surface of the core layer and having a cladding layer having a refractive index lower than that of the core portion,
The clad layer is composed mainly of a norbornene-based polymer containing a repeating unit of norbornene having an epoxy group and a substituent having an ether structure ,
The norbornene-based polymer is mainly an optical waveguide represented by the following chemical formula 1 .

[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. ]

(2) The optical waveguide according to (1) , wherein at least a part of the norbornene-based polymer is crosslinked at the epoxy group .

(3) The optical waveguide according to (1) or (2) , wherein an average thickness of the cladding layer is 0.1 to 1.5 times an average thickness of the core layer.

(4) 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 according to any one of (1) to (3), wherein the optical waveguide is obtained as the core portion and the other as the cladding portion.

(5) 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 according to the above (4) , which is an optical waveguide.

(6) 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 according to (4) or (5) , wherein the activation temperature varies.

(7) The activation temperature of the second substance is lowered by the action of the activated first substance, and irradiation with the actinic radiation is caused by heating at a temperature higher than the temperature of the heat treatment. The optical waveguide according to any one of (4) to (6), wherein the optical waveguide is activated completely.

(8) The optical waveguide according to (7) , 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. ]

(9) The optical waveguide according to (7) or (8) , 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. ]

(10) The optical waveguide according to (9) , wherein p and r are each selected from an integer of 1 or 2.

(11) The said core layer is obtained by heat-processing the said layer at the 2nd temperature higher than the temperature of the said heat processing after the said heat processing of said (4) thru | or (10). The optical waveguide according to any one of the above.

(12) 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 (11) ) .

(13) The optical waveguide according to (12) , wherein the third temperature is 20 ° C. or more higher than the second temperature.

(14) The optical waveguide according to any one of (4) to (13), wherein the monomer includes a crosslinkable monomer.

(15) The optical waveguide according to any one of (4) to (14), wherein the monomer is mainly a norbornene-based monomer.

(16) The optical waveguide according to (14) , wherein the monomer is mainly a norbornene-based monomer and contains dimethylbis (norbornenemethoxy) silane as the crosslinkable monomer.

(17) 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 according to any one of the above (4) to (16), wherein the leaving group of the polymer is released in the irradiated region when irradiated.

(18) 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 separated from the acid by the action of the cation. The optical waveguide according to (17) , which is a sex group.

(19) 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 according to any one of (1) to (3) above.

(20) The optical waveguide according to (19) , wherein the core layer is obtained by subjecting the layer to a heat treatment after irradiation with the active radiation.

(21) 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 according to (19) or (20) above.

(22) The light described in the above (18) or (21) , wherein the acid leaving group has at least one of an —O— structure, an —Si—aryl structure, and an —O—Si— structure. Waveguide.

(23) The optical waveguide according to any one of (17) to (22), wherein the leaving group causes a decrease in the refractive index of the polymer due to the leaving.

(24) The optical waveguide according to (23) , wherein the leaving group is at least one of a -Si-diphenyl structure and an -O-Si-diphenyl structure.

(25) The optical waveguide according to any one of (4) to (24), wherein the active radiation has a peak wavelength in a range of 200 to 450 nm.

(26) The optical waveguide according to any one of (4) to (25), wherein an irradiation amount of the active radiation is 0.1 to 9 J / cm ² .

(27) The optical waveguide according to any one of (4) to (26), wherein the active radiation is applied to the layer through a mask.

(28) The optical waveguide according to any one of (4) to (27), wherein the layer further includes an antioxidant.

(29) The optical waveguide according to any one of (4) to (28), wherein the layer further includes a sensitizer.

(30) The optical waveguide according to any one of (4) to (29), wherein the polymer is mainly a norbornene-based polymer.

(31) The optical waveguide according to (30) , wherein the norbornene-based polymer is an addition polymer.

(32) 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 the first norbornene-based material. The optical waveguide according to any one of (1) to (3) above.

(33) 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 according to the above (32) , wherein the refractive indexes thereof are different due to different contents of the objects.

(34) the reactants, the polymer of the norbornene monomer, cross-linked structure to crosslink the norbornene polymer with each other, and, at least is one above of the branch structure that branches from the norbornene-based polymer (33) An optical waveguide according to 1.

(35) The optical waveguide according to (33) or (34) , wherein the norbornene-based polymer includes a repeating unit of aralkyl norbornene.

(36) The optical waveguide according to (33) or (34) , wherein the norbornene-based polymer includes a repeating unit of benzylnorbornene.

(37) The optical waveguide according to (33) or (34) , wherein the norbornene-based polymer includes a repeating unit of phenylethylnorbornene.

(38) 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 detached 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 according to any one of (33) to (37), wherein the refractive indexes thereof are different due to being different.

(39) The core layer is composed of, as a main material, 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 first norbornene-based material and the second norbornene-based materials, by the number of the cleavable groups of the conditions attached to the main chain is different, according to their above refractive index is different (32) Optical waveguide.

(40) The optical waveguide according to (38) or (39) , wherein the norbornene-based polymer contains a repeating unit of diphenylmethylnorbornenemethoxysilane.

(41) The optical waveguide according to any one of (33) to (40), wherein the norbornene-based polymer includes an alkylnorbornene repeating unit.

(42) The optical waveguide according to any one of (33) to (40), wherein the norbornene-based polymer includes a repeating unit of hexylnorbornene.

(43) The optical waveguide according to any one of (33) to (42), wherein the norbornene-based polymer is an addition polymer.

(44) An optical waveguide structure comprising the optical waveguide according to any one of (1) to (43) and a conductor layer provided on at least one surface side of the optical waveguide.

(45) The optical waveguide structure according to (44) , wherein an average thickness of the conductor layer is 10 to 90% of an average thickness of the optical waveguide.

(46) The optical waveguide structure according to the above (44) or (45) , wherein the conductor layer is formed by at least one of a dry plating method, a wet plating method, and a bonding of a conductive sheet material. body.

  According to the present invention, since the cladding layer is composed of a norbornene polymer as a main material, the cladding layer is softened even when heat treatment such as soldering is performed when the optical waveguide is mounted on the circuit board. Is prevented. Further, even when the optical waveguide is left in a high humidity environment, the dimensional change due to water absorption of the cladding layer hardly occurs, and light can be stably propagated regardless of the use environment. Furthermore, the material cost for the cladding layer can be kept low.

  In addition, since the norbornene-based polymer includes a norbornene repeating unit having a substituent containing a polymerizable group, in the cladding layer, the polymerizable groups of at least a part of the norbornene-based polymer can be directly or cross-linked. Can be cross-linked. Depending on the type of polymerizable group, the type of crosslinking agent, the type of polymer used in the core layer, and the like, the norbornene-based polymer and the polymer used in the core layer can be cross-linked. As a result, the strength of the cladding layer itself can be improved, and the adhesion between the cladding layer and the core layer can be improved.

  And when it has an epoxy group as a polymeric group, the said effect can be improved more.

  Further, when a conductor layer is formed on at least one surface side of the optical waveguide, the electronic component can be electrically connected using the conductor layer, and the electronic component and the optical waveguide are mixed. A circuit board can be easily obtained.

  Hereinafter, the optical waveguide and 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 (partially cut away) showing an embodiment of an optical waveguide structure of the present invention.

In the following description, the upper side in FIG. 1 is “upper” or “upper”, and the lower side is “lower” or “lower” (the same applies to the following drawings).
Each figure is exaggerated in the thickness direction of the layer (the vertical direction in each figure).

  The optical waveguide structure 9 shown in FIG. 1 has an optical waveguide 90 and conductor layers 901 and 902 provided on the upper surface and the lower surface, respectively, and these layers are bonded.

  The constituent materials of the conductor layers 901 and 902 are, for example, various metal materials such as copper, copper-based alloy, aluminum, and aluminum-based alloy, indium tin oxide (ITO), and fluorine-containing indium tin oxide (FTO). And various oxide materials.

  The average thicknesses of the conductor layers 901 and 902 are each preferably about 10 to 90% of the average thickness of the optical waveguide 90, and more preferably about 20 to 80%. Specifically, the average thickness of the conductor layers 901 and 902 is not particularly limited, but is usually preferably about 3 to 100 μm and more preferably about 5 to 70 μm. Thereby, it is possible to make the conductor layers 901 and 902 excellent in conductivity while preventing the flexibility of the optical waveguide structure 9 from being lowered.

  Moreover, in the structure shown in FIG. 1, both the conductor layers 901 and 902 have comprised flat form (sheet form). In this case, after processing into a predetermined pattern of the conductor layers 901 and 902, an optical element (light emitting element, light receiving element, etc.) is mounted at a desired location, thereby manufacturing a composite device including an optical circuit and an electric circuit. can do.

  The conductor layers 901 and 902 may be previously patterned (wiring). Moreover, you may abbreviate | omit either one of the conductor layers 901 and 902 as needed.

  Further, between the conductor layers 901 and 902 and the optical waveguide 90, one layer or two or more layers for any purpose (for example, the purpose of improving adhesion) may be provided.

  The optical waveguide 90 is formed by laminating a clad layer (lower clad layer) 91, a core layer 93, and a clad layer (upper clad layer) 92 in this order from the lower side in FIG. A pattern core portion 94 and a clad portion 95 adjacent to the core portion (waveguide channel) 94 are formed.

  The difference in refractive index between the core portion 94 and the clad portion 95 is not particularly limited, but is preferably about 0.3 to 5.5%, and particularly preferably about 0.8 to 2.2%. If the difference in refractive index is less than the lower limit, the effect of transmitting light may be reduced, and even if the upper limit is exceeded, no further increase in light transmission efficiency can be expected.

The refractive index difference is expressed by the following equation, where A is the refractive index of the core portion 94 and B is the refractive index of the cladding portion 95.
Refractive index difference (%) = | A / B-1 | × 100

  In the configuration shown in FIG. 1, the core portion 94 is formed in a straight line shape in a plan view, but may be curved or branched in the middle, and the shape is arbitrary. In addition, if the manufacturing method of the optical waveguide structure 9 which is mentioned later is used, the core part 94 of a complicated and arbitrary shape can be formed easily and with a sufficient dimensional accuracy.

  The core section 94 has a quadrangular shape such as a square shape or a rectangular shape (rectangular shape).

  The width and height of the core portion 94 are not particularly limited, but are preferably about 1 to 200 μm, more preferably about 5 to 100 μm, and still more preferably about 10 to 60 μm.

  The core portion 94 is made of a material having a higher refractive index than that of the cladding portion 95, and is also made of a material having a higher refractive index than the cladding layers 91 and 92.

  The clad layers 91 and 92 constitute the clad portions located at the lower part and the upper part of the core part 94, respectively. With such a configuration, the core portion 94 functions as a light guide path whose outer periphery is surrounded by the cladding portion.

  The average thickness of the clad layers 91 and 92 is preferably about 0.1 to 1.5 times the average thickness of the core layer 93, more preferably about 0.3 to 1.25 times, Specifically, the average thickness of the clad layers 91 and 92 is not particularly limited, but it is usually preferably about 1 to 200 μm, more preferably about 5 to 100 μm, and about 10 to 60 μm. More preferably. Thereby, the function as a clad layer is suitably exhibited while preventing the optical waveguide 90 from becoming unnecessarily large (pressure film).

  The constituent materials of the clad layer 91, the clad portion 95, and the clad layer 92 may be the same (same type) or different from each other, but they have the same or similar refractive index. Is preferred. Details of the constituent materials of the cladding layers 91 and 92 and the core layer 93 will be described later.

  The optical waveguide structure 9 of the present invention is slightly different depending on the optical characteristics of the material of the core portion 94 and is not particularly limited. For example, the optical waveguide structure 9 is preferably used in data communication using light in the wavelength region of about 600 to 1550 nm. The

Next, an example of a method for manufacturing the optical waveguide structure 9 will be described.
<First manufacturing method>
First, the 1st manufacturing method of the optical waveguide structure 9 is demonstrated.

  2-7 is sectional drawing which shows typically the process example of the 1st manufacturing method of the optical waveguide structure of this invention, respectively.

[1A] First, a layer 910 is formed over a supporting substrate 951 (see FIG. 2).
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), combination of ROMP and hydrogenation reaction, polymerization by radical or cation, polymerization using a cationic palladium polymerization initiator, and other polymerization initiators ( For example, it can be obtained by any known polymerization method such as polymerization using a polymerization initiator of nickel or another transition metal).

  Among these, as the norbornene-based polymer, those having at least one repeating unit represented by the following chemical formula 2 (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-based polymer is suitably synthesized by using, for example, a norbornene-based monomer described later (a norbornene-based monomer represented by Chemical Formula 4 described below or a crosslinkable norbornene-based 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 the norbornene-based polymer containing the alkylnorbornene repeating unit has high flexibility, high flexibility (flexibility) can be imparted to the optical waveguide 90 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. Such a norbornene-based polymer is preferable because of its excellent transmittance with respect to light in the wavelength region as described above (particularly in the wavelength region near 850 nm).

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

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

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

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

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

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

  When the refractive index of the irradiated region in the layer 910 decreases due to the 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 90) having excellent optical transmission performance and excellent 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 3 (structural formula A), and examples thereof include compounds represented by the following chemical formula 4 (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 following cyclic group of Chemical formula 5 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 5, 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 6.

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

  The use of the crosslinkable monomer has the following advantages. That is, since the crosslinkable monomer is polymerized faster, the time required for the formation (process) of the core layer 93 (optical waveguide 90) 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 3 (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 (7).

［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 the sake of simplification, norbornadiene is included in the continuous polycyclic ring system and is considered to include 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 (8).

  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 9.

［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 10, chemical formula 11, chemical formula 12, chemical formula 13, and chemical formula 14, as well as fluorine-containing compounds represented by chemical formulas 15 and 16. Fluorine-containing crosslinkable norbornene-based monomers), but is not limited thereto.

  The compound represented by the formula 11 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 cladding 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 90) 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 90) can be formed by heat treatment at a relatively low temperature, and unnecessary heat is applied to the other layers, which degrades the characteristics (optical transmission performance) of the optical waveguide 90. Can be prevented.

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

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

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

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

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

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

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

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

Such a catalyst precursor includes (mainly) one containing at least one of Pd (OAc) ₂ (P (i-Pr) ₃ ) ₂ and Pd (OAc) ₂ (P (Cy) ₃ ) _2. Is preferred.

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

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

  As the cocatalyst (cocatalyst), any compound can be used as long as it has a molecular structure that changes (reacts or decomposes) when activated by irradiation with actinic radiation. A compound (photoinitiator) that decomposes upon irradiation with actinic radiation and generates a cation such as a proton or other cation and a weakly coordinated anion (WCA) that can be substituted with a leaving group of the catalyst precursor ( (Mainly) is preferably used.

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

  Examples of the promoter (photoacid generator or photobase generator) include tetrakis (pentafluorophenyl) borate and hexafluoroantimonate represented by the following chemical formula 18 as well as 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 90) 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 (active energy light) 930 through the mask 935 (FIG. 3). reference).

  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. 3, an opening (window) 9351 equivalent to the pattern of the clad portion 95 to be formed is shown by partially removing the mask along the pattern of the unirradiated region 940 of the active radiation 930. In the case of using a photomask made of quartz glass, PET base material, or the like, it is also possible to use a photomask provided with a shielding portion of active radiation 930 made of a shielding material made of metal such as chromium. it can. 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.

  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 rises 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. 4).

  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.

[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 step [4A] may be omitted.

  [6A] Next, the cladding layer 91 (92) is formed on the support substrate 952 (see FIG. 5).

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

When the clad layer 91 (92) is formed by a coating method, examples thereof include a spin coating method, a dipping method, a table coating method, a spray method, an applicator method, a curtain coating method, and a die coating method.
As the support substrate 952, a substrate similar to the support substrate 951 can be used.

  As a constituent material of the clad layer 91 (92), a material mainly composed of a norbornene polymer is used. Since the norbornene-based polymer is excellent in heat resistance, when the conductor layers 901 and 902 are formed on the optical waveguide 90 in the optical waveguide 90 using this as a constituent material of the cladding layer 91 (92), the conductor layers 901 and 902 are formed. Even when heated to mount an optical element or the like when forming the wiring by processing, the cladding layer 91 (92) can be prevented from being softened and deformed.

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

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

  Further, when a material mainly composed of norbornene-based polymer is used as the material of the clad layer 91 (92), the material is preferably the same as the material suitably used as the constituent material of the core layer 93. Further, it becomes higher, and delamination between the clad layer 91 (92) and the core layer 93 can be prevented. For this reason, the optical waveguide 90 having excellent durability can be obtained.

  Examples of such norbornene-based polymers include (1) addition (co) polymers of norbornene monomers obtained by addition (co) polymerization of norbornene monomers, and (2) norbornene monomers and ethylene or α-olefins. (3) addition polymers such as addition copolymers with norbornene-type monomers and non-conjugated dienes, and other monomers as required, (4) ring opening of norbornene-type monomers ( A (co) polymer, and a resin obtained by hydrogenating the (co) polymer if necessary, (5) a ring-opening copolymer of a norbornene-type monomer and ethylene or α-olefins, and ( (Co) polymer hydrogenated resin, (6) ring-opening copolymer of norbornene type monomer and non-conjugated diene or other monomer, and (co) polymerization if necessary And a ring-opening polymer such as a polymer obtained by hydrogenating the body. Examples of these polymers include random copolymers, block copolymers, and alternating copolymers.

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

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

  The norbornene-based polymer preferably includes a norbornene repeating unit having a substituent containing a polymerizable group. Thereby, in the clad layer 91 (92), the polymerizable groups of at least a part of the norbornene-based polymer 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 (92) itself can be improved, and the adhesion between the clad layer 91 (92) and the core layer 93 can be improved.

  Examples of such a polymerizable group include one or a combination of two or more of an epoxy group, a (meth) acryl group, an alkoxysilyl group, and the like, and an epoxy group is particularly preferable. Epoxy groups are preferred because of their high reactivity among various polymerizable groups.

  Further, the norbornene-based polymer preferably contains an alkylnorbornene repeating unit. The alkyl group may be linear or branched. Since the norbornene-based polymer containing the alkylnorbornene repeating unit has high flexibility, high flexibility (flexibility) can be imparted to the optical waveguide 90 by using such norbornene-based polymer.

  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).

  Therefore, as the norbornene-based polymer used for the clad layer 91 (92), those represented by the following chemical formula 19 are suitable.

［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. ]

  Such a norbornene-based polymer has a relatively low refractive index in addition to the above-described characteristics. By forming the clad layer 91 (92) using such a norbornene-based polymer as a main material, the optical transmission performance of the optical waveguide 90 is achieved. Can be further improved.

  Among the norbornene-based polymers represented by Chemical formula 19, compounds in which R is an alkyl group having 4 to 10 carbon atoms and a and b are each 1, for example, butylbornene and methylglycidyl ether norbornene A copolymer, 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.

  Moreover, although p / q 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 2 types of norbornene is exhibited.

  In order to directly crosslink epoxy groups in a norbornene-based polymer containing a norbornene-based repeating unit having a substituent containing an epoxy group, the same kind of substance as the above-mentioned promoter (light) is used in the cladding layer forming material. An acid generator or a photobase generator) may be mixed, and the epoxy group may be cleaved and crosslinked by the action of this substance.

  In addition, in order to crosslink epoxy groups via a crosslinking agent, a compound having at least one epoxy group as a crosslinking agent may be further mixed in the cladding layer forming material.

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

  This cross-linking reaction between the epoxy groups may be performed at the final stage of this step [6A], or may be performed after obtaining the optical waveguide 90 in the next step [7A].

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

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

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

Examples of such catalyst precursors include [Pd (PCy ₃ ) ₂ (O ₂ CCH ₃ ) (NCCH ₃ )] tetrakis (pentafluorophenyl) borate, [2-methylly Pd (PCy3) 2] tetrakis (pentafluorophenyl). ) Borate, [Pd (PCy3) 2H (NCCH3)] tetrakis (pentafluorophenyl) borate, [Pd (P (iPr) 3) 2 (OCOCH3) (NCCH3)] tetrakis (pentafluorophenyl) borate, and the like.

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

  [7A] Next, the core layer 93 is peeled from the support substrate 951, and the core layer 93 is sandwiched between the support substrate 952 on which the cladding layer 91 is formed and the support substrate 952 on which the cladding layer 92 is formed ( (See FIG. 6).

Then, as indicated by the arrows in FIG. 6, pressure is applied from the upper surface side of the support substrate 952 on which the cladding layer 92 is formed, and the cladding layers 91 and 92 and the core layer 93 are pressure bonded.
Thereby, the clad layers 91 and 92 and the core layer 93 are joined and integrated.

  Further, this crimping operation is preferably performed under heating. The heating temperature is appropriately determined depending on the constituent materials of the clad layers 91 and 92 and the core layer 93, and is usually preferably about 80 to 200 ° C, more preferably about 120 to 180 ° C.

  Next, the support substrate 952 is peeled off and removed from the cladding layers 91 and 92, respectively. Thereby, the optical waveguide 90 of the present invention is obtained.

  [8A] Next, conductor layers 901 and 902 are formed on the upper and lower surfaces of the optical waveguide 90, respectively (see FIG. 7).

As a method for forming each of the conductor layers 901 and 902, for example, a chemical vapor deposition method (CVD method) such as a plasma CVD method, a thermal CVD method, or a laser CVD method, a vacuum deposition method, a sputtering method, or an ion is used. Among the bonding of conductive sheet materials by dry plating methods such as physical vapor deposition methods (PVD methods) such as plating methods, wet plating methods such as electrolytic plating, immersion plating and electroless plating, and laminating methods At least one of the following can be used. Thereby, high adhesiveness between each of the conductor layers 901 and 902 and the optical waveguide 90 is obtained.
As described above, the optical waveguide structure 9 of the present invention is completed.

  In a preferable example of such an optical waveguide structure 9, in the core layer 93, the core portion 94 is configured 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 second norbornene-based material having a main material, and the clad layers 91 and 92 having a refractive index lower than that of the first norbornene-based material (the core portion 94 of the core layer 93), respectively. Composed.

  The first norbornene-based material and the second norbornene-based material both contain the same norbornene-based polymer, but contain a reaction product of a norbornene-based monomer having a refractive index different from that of the norbornene-based polymer. Due to the different amounts, the refractive indices are different from each other.

  Since the norbornene-based polymer has high transparency, the optical waveguide structure 9 having such a configuration can provide high optical transmission performance of the optical waveguide 90.

  Further, with such a configuration, not only high adhesion between the core portion 94 and the clad portion 95 but also high adhesion between the core layer 93, the clad layer 91, and the clad layer 92 can be obtained. Even when deformation such as bending occurs in the structure 9, peeling between the core portion 94 and the clad portion 95 and delamination between the core layer 93 and the clad layers 91 and 92 do not easily occur. It is also possible to prevent micro cracks from occurring in 95. As a result, the optical transmission performance of the optical waveguide 90 is maintained.

  Further, since the norbornene-based polymer has high heat resistance and high hydrophobicity, the optical waveguide 90 (optical waveguide structure 9) having such a configuration has excellent durability.

  In addition, since high heat resistance and high hydrophobicity can be imparted to the optical waveguide 90, the conductor layers 901 and 902 can be formed by adopting various methods as described above while preventing deterioration (deterioration) of the characteristics. It can be reliably formed. In particular, even when the conductor layers 901 and 902 are formed so as to overlap with the core portion 94 important for light transmission, the core portion 94 can be prevented from being deteriorated or deteriorated.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

[2B] A step similar to the step [2A] is performed.
When the layer 910 is irradiated with the 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.
[6B] A step similar to the step [8A] is performed.
As described above, the optical waveguide structure 9 of the present invention is completed.

  In a preferred example of such an optical waveguide structure 9, the core layer 93 is composed of a norbornene-based material as a main material, and the cladding layers 91 and 92 each have a lower refractive index than the core portion 94 of the core layer 93. It is composed mainly of polymer.

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

  Since the norbornene-based polymer has high transparency, the optical waveguide structure 9 having such a configuration can provide high optical transmission performance of the optical waveguide 90.

  Further, with such a configuration, not only high adhesion between the core portion 94 and the clad portion 95 but also high adhesion between the core layer 93, the clad layer 91, and the clad layer 92 can be obtained. Even when deformation such as bending occurs in the structure 9, peeling between the core portion 94 and the clad portion 95 and delamination between the core layer 93 and the clad layers 91 and 92 do not easily occur. It is also possible to prevent micro cracks from occurring in 95. As a result, the optical transmission performance of the optical waveguide 90 is maintained.

  Further, since the norbornene-based polymer has high heat resistance and high hydrophobicity, the optical waveguide 90 (optical waveguide structure 9) having such a configuration has excellent durability.

  In addition, since high heat resistance and high hydrophobicity can be imparted to the optical waveguide 90, the conductor layers 901 and 902 can be formed by adopting various methods as described above while preventing deterioration (deterioration) of the characteristics. It can be reliably formed. In particular, even when the conductor layers 901 and 902 are formed so as to overlap with the core portion 94 important for light transmission, the core portion 94 can be prevented from being deteriorated or deteriorated.

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

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

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

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

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

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

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

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

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

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

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

[2C] A step similar to the step [2A] is performed.
When the layer 910 is irradiated with the active radiation 930 through the mask 935, the cocatalyst (first substance: cocatalyst) present in the irradiation region 925 irradiated with the active radiation 930 reacts by the action of the active radiation 930. Alternatively, it decomposes to liberate (generate) cations (protons or other cations) and weakly coordinating anions (WCA).

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

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

  As a result, in the irradiated region 925, the number of leaving groups in a complete state is reduced as compared with the non-irradiated 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 rises 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.
[8C] The same step as the above step [8A] is performed.
As described above, the optical waveguide structure 9 of the present invention is completed.

  In a preferred example of such an optical waveguide structure 9, the core layer 93 is a norbornene 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 reaction product of a norbornene monomer having a refractive index different from that of the norbornene polymer. Due to the different contents, the refractive indexes thereof are different, and the cladding layers 91 and 92 are mainly composed of a norbornene-based 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, the optical waveguide structure 9 having such a configuration can provide high optical transmission performance of the optical waveguide 90.

  Further, with such a configuration, not only high adhesion between the core portion 94 and the clad portion 95 but also high adhesion between the core layer 93, the clad layer 91, and the clad layer 92 can be obtained. Even when deformation such as bending occurs in the structure 9, peeling between the core portion 94 and the clad portion 95 and delamination between the core layer 93 and the clad layers 91 and 92 do not easily occur. It is also possible to prevent micro cracks from occurring in 95. As a result, the optical transmission performance of the optical waveguide 90 is maintained.

  Further, since the norbornene-based polymer has high heat resistance and high hydrophobicity, the optical waveguide 90 (optical waveguide structure 9) having such a configuration has excellent durability.

  In addition, since high heat resistance and high hydrophobicity can be imparted to the optical waveguide 90, the conductor layers 901 and 902 can be formed by adopting various methods as described above while preventing deterioration (deterioration) of the characteristics. It can be reliably formed. In particular, even when the conductor layers 901 and 902 are formed so as to overlap with the core portion 94 important for light transmission, the core portion 94 can be prevented from being deteriorated or deteriorated.

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

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

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

  8 to 13 are cross-sectional views schematically showing process examples of the fourth manufacturing method of the optical waveguide structure of the present invention.

  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 formation process of the optical waveguide 90 is different, and the other processes are the same as those in the first to third manufacturing methods.

  That is, as the core layer forming material 900 and the clad layer forming material, the same materials as described in the first to third manufacturing methods can be used.

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

[1D] First, a clad layer forming material (first varnish) is applied onto the support substrate 1000 using the same method as described above to form the first layer 1110 (see FIG. 8). .
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. 9).

  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 90, the adhesion between the clad layer 91 and the core layer 93 can be improved.

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

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

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

[3D] Next, a clad layer forming material (third varnish) is applied onto the second layer 1120 using the same method as described above to form the third layer 1130 (FIG. 10).
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 active radiation (active energy ray) 930 is irradiated to the stacked body 2000 through the mask 935 (FIG. 11).

  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 rises 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. 12).

[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.
Through the above steps, the optical waveguide 90 of the present invention is obtained.

  [9D] Next, conductor layers 901 and 902 are formed on the upper and lower surfaces of the optical waveguide 90, respectively (see FIG. 13).

This can be performed in the same manner as in the step [8A].
As described above, the optical waveguide structure 9 of the present invention is completed.

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

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

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

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

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

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

  In the fourth production method, it is preferable to use the first varnish and the third varnish containing a norbornene-based polymer having a substituent containing an epoxy structure at the terminal and a promoter. Thereby, when forming the core part 94 and the clad part 95, an epoxy structure is cleaved and a reaction (polymerization) with the polymer 915 of the core layer 93 comes to occur. As a result, the adhesion of the cladding layers 91 and 92 to the core layer 93 can be improved.

  Examples of such norbornene-based polymers include copolymers of hexyl norbornene (HxNB) and norbornene methyl glycidyl ether (AGENB).

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

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

  The optical waveguide structure 9 as described above can pattern the core portion 94 by a simple method of irradiation with actinic radiation, and the degree of freedom in designing the pattern shape of the core portion (optical circuit) 94 is wide. And the core part 94 with high dimensional accuracy is obtained.

  In addition, since the conductor layers 901 and 902 are formed in advance, wiring to the element (formation of an electric circuit) is easy, and wiring suitable for it is possible regardless of the type of element (terminal installation location). Therefore, the degree of freedom of the configuration of the wiring circuit (for example, the degree of freedom of selection of the terminal installation location) is wide and versatile.

  Since the optical waveguide structure 9 can form both the wiring (electric circuit) and the core portion (optical circuit) 94 with a high arrangement density, an efficient circuit design in a hybrid optical and electric circuit. As well as further circuit integration.

  Such an optical waveguide structure 9 has a wide range of optical circuit (optical waveguide pattern) and electrical circuit design, good yield, high optical transmission performance, excellent reliability and durability, and versatility. Therefore, it can be used for various electronic parts and electronic devices.

  In each of the first to fourth manufacturing methods, the support substrates 951, 952, and 1000 have been described as being removed. However, these are made of a conductive material, and the conductor layer 901 is left as it is without being removed. , 902 may be used.

  Moreover, you may abbreviate | omit either one or both of the clad layers 91 and 92 as needed.

  Needless to say, the method of forming the core layer 93 is not limited to the method described above.

  Further, the optical waveguide 90 is not limited to the configuration shown in the figure. For example, the optical waveguide 90 may have a configuration in which a plurality of core layers are provided between two cladding layers. May be laminated in order, or a laminated body in which a single core layer is provided between two clad layers may be laminated.

  In addition, an inclined surface (reflecting surface) inclined by approximately 45 ° with respect to the optical path, that is, the longitudinal direction of the core portion 94 may be formed in the middle of the core portion 94. Thereby, the light (transmission light) propagating through the core portion 94 can be bent by approximately 90 ° on this inclined surface.

  Then, by appropriately setting the direction of the inclined surface, the optical path of the transmitted light is changed not only in the core layer 90 (two-dimensional direction) but also in a three-dimensional direction including the thickness direction of the optical waveguide 90. Is possible.

  This inclined surface can be formed by, for example, cutting or removing (deleting) the core portion 94. 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 may be formed on the inclined surface.

  As described above, the optical waveguide and the optical waveguide structure of the present invention have been described based on the illustrated embodiments. However, the present invention is not limited to these, and the configuration of each part is an arbitrary one that can exhibit the same function. In addition, an arbitrary configuration may be added.

Hereinafter, specific examples of the present invention will be described.
In the following, hexyl norbornene (CAS number 22094-83-3) is “HxNB”, diphenylmethylnorbornene methoxysilane (CAS number 376634-34-3) is “diPhNB”, phenylethyl norbornene ( CAS number 29415-09-6) is “PENB”, butylnorbornene (CAS number 22094-81-1) is “BuNB”, and decylnorbornene (CAS number 22094-85-5) is “ DeNB ", benzylnorbornene (CAS number 2665989-73-9)" BzNB ", methylglycidyl ether norbornene (CAS number 3188-75-8)" AGENB ", norbornenylethyltrimethoxy Silane (CAS No. 68245-19- No.) "TMSENB", triethoxysilyl norbornene (CAS number 18401-43-9) "TESNB", trimethoxysilyl norbornene (CAS number 7538-46-7) "TMSNB", Dimethylbis (norbornenemethoxy) silane (CAS No. 376609-87-9) is replaced with “SiX” and 1,1,3,3-tetramethyl-1,3-bis [2- (5-norbornene-2- Yl) ethyl] disiloxane (CAS No. 198570-39-7) may be abbreviated as “Si ₂ X”, respectively.

1. Synthesis of Polymer and Preparation of Polymer Solution As shown below, each polymer P1-5 was synthesized and the solution was prepared.
<< Polymer P1: Synthesis of Butyl Norbornene (BuNB) / Methyl Glycidyl Ether Norbornene (AGENB) Copolymer and Preparation of Polymer P1 Solution >>

  BuNB (10.52 g, 0.07 mol), AGENB (5.41 g, 0.03 mol), and toluene (58.0 g) are mixed in a sealum bottle and heated to 80 ° C. in an oil bath to obtain a mixed solution. Got.

Next, a toluene solution (5 g) of (η ⁶ -toluene) Ni (C ₆ F ₅ ) ₂ (0.69 g, 0.0014 mol) was added to this solution.

  After the addition, the resulting solution was maintained at room temperature for 4 hours. Next, a toluene solution (87.0 g) was added to the reaction solution, and methanol was added dropwise to the vigorously stirred reaction mixture to precipitate a copolymer.

  The precipitated copolymer was collected by filtration and dried in a vacuum atmosphere in an oven at 60 ° C. The weight after drying was 12.74 g (yield: 80%).

  When the molecular weight of the copolymer obtained above was measured by GPC method (gel permeation chromatography method) with a THF solvent (in terms of polystyrene), it was Mw = 320,000 and Mn = 130,000.

The copolymer composition was determined by ¹ H-NMR to be 78/22 = BuNB / AGENB copolymer.

  When the refractive index of the copolymer was measured by the prism coupling method, it was 1.5162 in the TE mode and 1.5157 in the TM mode at a wavelength of 633 nm.

  And the dried copolymer was melt | dissolved in toluene, and it was set as the 30 wt% polymer P1 solution.

<< Polymer P2: Synthesis of Hexyl Norbornene (HxNB) / Methyl Glycidyl Ether Norbornene (AGENB) Copolymer and Preparation of Polymer P2 Solution >>

  HxNB (12.48 g, 0.07 mol), AGENB (5.41 g, 0.03 mol), and toluene (58.0 g) were added to the sealum bottle in the dry box and the solution was added to an 80 ° C. oil bath. Stir in.

Next, a toluene solution (5 g) of (η ⁶ -toluene) Ni (C ₆ F ₅ ) ₂ (0.69 g, 0.0014 mol) was added to this solution.

  After the addition, the resulting mixture was maintained at room temperature for 4 hours. Next, a toluene solution (87.0 g) was added to the reaction solution, and methanol was added dropwise to the vigorously stirred reaction mixture to precipitate a copolymer.

  The precipitated copolymer was collected by filtration and dried in an oven at 60 ° C. under vacuum. The weight after drying was 13.78 g (yield: 77%).

  When the molecular weight of the copolymer obtained above was measured by the GPC method with a THF solvent (polystyrene conversion), Mw = 150,000 and Mn = 76,000.

The copolymer composition was determined by ¹ H-NMR to be 79/21 = HxNB / AGENB copolymer.

  When the refractive index of the copolymer was measured by the prism coupling method, it was 1.5159 in the TE mode and 1.5153 in the TM mode at a wavelength of 633 nm.

  And the dried copolymer was melt | dissolved in toluene, and it was set as the 30 wt% polymer P2 solution.

<< Polymer P3: Synthesis of Decyl Norbornene (DeNB) / Methyl Glycidyl Ether Norbornene (AGENB) Copolymer and Preparation of Polymer P3 Solution >>

  DeNB (16.4 g, 0.07 mol), AGENB (5.41 g, 0.03 mol), and toluene (58.0 g) were added to the sealum bottle in the dry box, and this solution was added to an 80 ° C. oil bath. Stir in.

Next, a toluene solution (5 g) of (η ⁶ -toluene) Ni (C ₆ F ₅ ) ₂ (0.69 g, 0.0014 mol) was added to this solution.

  After the addition, the resulting mixture was maintained at room temperature for 4 hours. Next, a toluene solution (87.0 g) was added to the reaction solution, and methanol was added dropwise to the vigorously stirred reaction mixture to precipitate a copolymer.

  The precipitated copolymer was collected by filtration and dried in a vacuum atmosphere in an oven at 60 ° C. The weight after drying was 17.00 g (yield: 87%).

  When the molecular weight of the copolymer obtained above was measured by a GPC method using a THF solvent (polystyrene conversion), it was Mw = 45,000 and Mn = 26,000.

The composition of the copolymer was measured by ¹ H-NMR and found to be 77/23 = DeNB / AGENB copolymer.

  When the refractive index of the copolymer was measured by the prism coupling method, it was 1.5153 in the TE mode and 1.5151 in the TM mode at a wavelength of 633 nm.

  And the dried copolymer was melt | dissolved in toluene, and it was set as the 30 wt% polymer P3 solution.

<< Polymer P4: Synthesis of Hexyl Norbornene (HxNB) / Diphenylmethyl Norbornene Methoxysilane (diPhNB) Copolymer and Preparation of Polymer P4 Solution >>

  HxNB (8.94 g, 0.050 mol), diPhNB (16.1 g, 0.050 mol), 1-hexene (2.95 g, 0.035 mol), and toluene (142 g) were weighed into a 250 mL sealam bottle. And heated to 80 ° C. in an oil bath to obtain a mixed solution.

Next, [Pd (PCy ₃ ) ₂ (O ₂ CCH ₃ ) (NCCH ₃ )] tetrakis (pentafluorophenyl) borate (hereinafter abbreviated as “Pd1446”) (5.8 × 10 ⁻³ g) was added to this solution. , 4.0 × 10 ⁻⁶ mol) and N, N-dimethylanilinium tetrakis (pentafluorophenyl) borate (hereinafter abbreviated as “DANFABA”) (3.2 × 10 ⁻³ g, 4. 0 × 10 ⁻⁶ mol) was added.

  At this time, the ratio of norbornene monomer / Pd1446 / DANFABA was 25000/1/1 in molar ratio.

  The mixture was maintained at 80 ° C. for 7 hours, after which 20 mL of acetonitrile was added to quench the activity of the Pd catalyst. Thereafter, when methanol was added dropwise to the reaction mixture, the copolymer was precipitated.

  The precipitated copolymer was collected by filtration and dried in a vacuum atmosphere in an oven at 60 ° C. The weight after drying was 19.8 g (yield: 79%).

  When the molecular weight of the copolymer obtained above was measured by the GPC method with a THF solvent (polystyrene conversion), it was Mw = 86,000 and Mn = 21,000.

The copolymer composition was 46/54 = HxNB / diPhNB copolymer as measured by ¹ H-NMR.

  When the refractive index of the copolymer was measured by the prism coupling method, it was 1.5569 in the TE mode and 1.5556 in the TM mode at a wavelength of 633 nm.

  And the dried copolymer was melt | dissolved in toluene, and it was set as the 30 wt% polymer P4 solution.

<< Polymer P5: Synthesis of Butylnorbornene (BuNB) / Phenylethylnorbornene (PENB) Copolymer and Preparation of Polymer P5 Solution >>

  BuNB (4.78 g, 0.032 mol), PENB (25.22 g, 0.127 mol), 1-hexene (13.36 g, 0.16 mol), and toluene (170.0 g) were added to a 500 mL sealam bottle. And heated to 80 ° C. in an oil bath to obtain a mixed solution.

To this solution was then added Pd1446 (0.0092 g, 6.36 × 10 ⁻⁶ mol) and DANFABA (0.020 g, 2.54 × 10 ⁻⁵ mol), each in the form of a concentrated dichloromethane solution. It was.

  After the addition, the resulting solution was maintained at 80 ° C. for 50 minutes. Next, when methanol was added dropwise to the vigorously stirred mixture, a copolymer was precipitated.

  The precipitated copolymer was collected by filtration and dried in a vacuum atmosphere in an oven at 60 ° C. The weight after drying was 23.60 g (yield: 79%).

  When the molecular weight of the copolymer obtained above was measured by a GPC method using a THF solvent (polystyrene conversion), it was Mw = 73,000 and Mn = 28,000.

The composition of the copolymer was measured by ¹ H-NMR and found to be 15/85 = BuNB / PENB copolymer.

  When the refractive index of the copolymer was measured by the prism coupling method, it was 1.5684 in the TE mode and 1.5657 in the TM mode at a wavelength of 633 nm.

And the dried copolymer was melt | dissolved in toluene, and it was set as the 30 wt% polymer P5 solution.
Each polymer synthesized above is summarized in Table 1 below.

2. Synthesis of norbornene monomer << bis (norbornenemethyl) acetal (NM ₂ X) >>

  In a flask directly connected to the Dean-Stark trap, norbornenemethanol (100 g, 0.81 mol), formaldehyde (-37%) (32.6 g, 0.40 mol), and a suitable amount of p-toluenesulfonic acid (0 .2g) was fed to obtain a mixture.

  The mixture was then heated at 100 ° C. As the reaction progressed, the amount of water in the trap increased. Within about 3 hours, the reaction was complete and the pure product was obtained by vacuum distillation (72.8% -70% yield).

3. Preparation of varnish Each varnish V1-4 and V51-65 were prepared as follows.

<< Preparation of Varnish V1 >>
HxNB (42.03 g, 0.24 mol) and SiX (7.97 g, 0.026 mol) were weighed and placed in a glass bottle.

  CIR, IRGANOX 1076 (0.5 g) as a phenolic antioxidant, and Ciba, IRGAFOS 168 (0.125 g) as an organophosphorus antioxidant are added to the monomer solution. An antioxidant solution was obtained.

To the polymer P4 solution (30.0 g), a monomer antioxidant solution (3.0 g) and a catalyst precursor, Pd (OAc) ₂ (PCy ₃ ) ₂ (4.93 × 10 ⁻⁴ g, 6. 28 × 10 ⁻⁷ mol, in 0.1 mL of methylene chloride) and a photoacid generator (co-catalyst) manufactured by Rhodia, RHODROSIL PHOTOINITIATOR 2074 (2.55 × 10 ⁻³ g, 2.51 × 10 ^{− 6} mol, in 0.1 mL of methylene chloride) was added to obtain varnish V1.
This varnish V1 was used after being filtered with a 0.2 μm pore filter.

  In the following, “Ciba, IRGANOX 1076” is “IRGANOX 1076”, “Ciba, IRGAFOS 168” is “IRGAFOS 168”, “Rhodia, RHODORSIL PHOTOINITIATOR 2074” is “RHODORSIL 2074”. Abbreviated.

<< Preparation of Varnish V2 >>
HxNB (16.64 g, 0.093 mol) and SiX (33.36 g, 0.110 mol) were weighed and placed in a glass bottle.

  To this monomer solution, IRGANOX 1076 (0.5 g) as a phenolic antioxidant and IRGAFOS 168 (0.125 g) as an organophosphorus antioxidant were added to obtain a monomer antioxidant solution.

To the polymer P5 solution (30.0 g), a monomer antioxidant solution (2.16 g) and a catalyst precursor, Pd (OAc) ₂ (PCy ₃ ) ₂ (1.47 × 10 ⁻³ g, 1. 88 × 10 ⁻⁶ mol, in 0.1 mL of methylene chloride), and RHODORSIL 2074 (7.67 × 10 ⁻³ g, 7.54 × 10 ⁻⁶ mol, methylene chloride) as a photoacid generator (promoter) In 0.1 mL) was added to obtain varnish V2.
This varnish V2 was used after being filtered with a 0.2 μm pore filter.

<< Preparation of Varnish V3 >>
Into the above polymer P4 (5 g), mesitylene (20 g), IRGANOX 1076 (0.05 g) as a phenolic antioxidant, IRGAFOS 168 (0.0125 g) as an organic phosphorus antioxidant, and photoacid generation As an agent (release agent), RHODORSIL 2074 (4.0 × 10 ⁻³ g, in 0.1 mL of methylene chloride) was added to prepare varnish V3.
This varnish V3 was used after being filtered with a 0.2 μm pore filter.

<< Preparation of Varnish V4 >>
2,2′-bis (trifluoromethyl) -4,4′-diaminobiphenyl (6.4 g, 0.02 mol), 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane dianhydride ( 4.44 g, 0.01 mol) and pyromellitic dianhydride (2.18 g, 0.01 mol) were dissolved in dimethylacetamide (86.6 g) and stirred at room temperature for 2 days in a nitrogen atmosphere. The polyimide resin precursor varnish V4 was obtained.
This varnish V4 was used after being filtered with a 0.2 μm pore filter.

<< Preparation of Varnish V51 >>
To the above polymer P2 solution (30.0 g), TMSENB (0.45 g), as a phenolic antioxidant, IRGAOX 1076 (0.09 g), as an organophosphorus antioxidant, IRGAFOS 168 (0.023 g), And TAG-372R (0.05g) by Toyo Ink Manufacturing Co., Ltd. was added as a photo-acid generator, and it melted and mixed by stirring for 2 hours using the magnetic stirrer, and obtained varnish V51.
This varnish V51 was used after being filtered with a 0.2 μm pore filter.

  Hereinafter, “TAG-372R manufactured by Toyo Ink Manufacturing Co., Ltd.” is abbreviated as “TAG-372R”.

<< Preparation of Varnish V52 >>
To the above polymer P2 solution (30.0 g), TENSB (0.9 g), as a phenolic antioxidant, IRGAOX 1076 (0.09 g), as an organic phosphorus antioxidant, IRGAFOS 168 (0.023 g), RHODORSIL 2074 (0.09 g) was added as a photoacid generator and dissolved and mixed by stirring for 2 hours using a magnetic stirrer to obtain varnish V52.
This varnish V52 was used after being filtered with a 0.2 μm pore filter.

<< Preparation of Varnish V53 >>
In the above polymer P2 solution (30.0 g), TMSNB (0.3 g), as a phenolic antioxidant, IRGAOX 1076 (0.09 g), as an organic phosphorus antioxidant, IRGAFOS 168 (0.023 g), And TAG-372R (0.36g) was added as a photo-acid generator, and it melted and mixed by stirring for 2 hours using the magnetic stirrer, and obtained varnish V53.
This varnish V53 was used after being filtered with a 0.2 μm pore filter.

<< Preparation of Varnish V54 >>
In the above polymer P2 solution (30.0 g), 3-glycidoxypropyltrimethoxysilane (GPTMS) (0.2 g), phenolic antioxidant as IRGANOX 1076 (0.09 g), organophosphorus antioxidant IRGAFOS 168 (0.023 g) as an agent and TAG-372R (0.02 g) as a photoacid generator were added and dissolved and mixed by stirring for 2 hours using a magnetic stirrer to obtain varnish V54. .
This varnish V54 was used after being filtered with a 0.2 μm pore filter.

<< Preparation of Varnish V55 >>
To the above polymer P2 solution (30.0 g), epoxy silicone (“X-22-169AS: number average molecular weight 1000” manufactured by Shin-Etsu Chemical Co., Ltd.) (0.45 g), IRGANOX 1076 ( 0.09 g), IRGAFOS 168 (0.023 g) as an organophosphorus antioxidant, and TAG-372R (0.18 g) as a photoacid generator, and stirring for 2 hours using a magnetic stirrer To obtain varnish V55.
This varnish V55 was used after being filtered with a 0.2 μm pore filter.

<< Preparation of Varnish V56 >>
In the above polymer P3 solution (16.7 g), IRGANOX 1076 (0.05 g) as a phenol-based antioxidant, IRGAFOS 168 (1.25 × 10 ⁻² g) as an organic phosphorus-based antioxidant, and RHODORSIL 2074 (0.1 g) was added as a photoacid generator, and dissolved and mixed by stirring for 2 hours using a magnetic stirrer to obtain varnish V56.
The varnish V56 was used after being filtered with a 0.2 μm pore filter.

<< Preparation of Varnish V57 >>
In the above polymer P3 solution (16.7 g), IRGANOX 1076 (0.05 g) as a phenol-based antioxidant, IRGAFOS 168 (1.25 × 10 ⁻² g) as an organic phosphorus-based antioxidant, and TAG-372R (0.1 g) was added as a photoacid generator, and dissolved and mixed by stirring for 2 hours using a magnetic stirrer to obtain varnish V57.
This varnish V57 was used after being filtered with a 0.2 μm pore filter.

<< Preparation of Varnish V58 >>
IRGANOX 1076 (0.05 g) as a phenolic antioxidant and IRGAFOS 168 (1.25 × 10 ⁻² g) as an organic phosphorus antioxidant to the polymer P3 solution (16.7 g). In addition, the mixture was dissolved and mixed by stirring for 2 hours using a magnetic stirrer to obtain varnish V58.
This varnish V58 was used after being filtered through a filter having a pore size of 0.2 μm.

<< Preparation of Varnish V59 >>
Dissolve 5 g of 2,2′-bis (trifluoromethyl) -4,4′-diaminobiphenyl and 10 g of 2,2′-bis (3,4-dicarboxyphenyl) hexafluoropropane in 85 g of dimethylacetamide. Thus, varnish V59 was obtained.
This varnish V59 was used after being filtered with a 0.2 μm pore filter.

<< Preparation of Varnish V60 >>
TMSENB (0.32 g, 1.50 mmol) and SiX (0.16 g, 0.525 mmol) were weighed and placed in a glass bottle.

  To this monomer solution, IRGANOX 1076 (0.5 g) as a phenolic antioxidant and IRGAFOS 168 (0.125 g) as an organophosphorus antioxidant were added to obtain a monomer antioxidant solution.

To the above polymer P3 solution (6.7 g), as a monomer antioxidant solution (total amount), and [2-methyllyl Pd (PCy3) 2] tetrakis (pentafluorophenyl) borate (Pd1401) (9 .37 × 10 ⁻⁴ g, 6.69 × 10 ⁻⁷ mol, in 0.1 mL of methylene chloride) was added to obtain varnish V60.
This varnish V60 was used after being filtered with a 0.2 μm pore filter.

  And this varnish V60 was apply | coated to the application | coating thickness of 70 micrometers with the doctor blade on the glass substrate, this was set | placed on the hotplate, and it heated at 50 degreeC for 15 minutes, and formed the film.

  Using this film, the glass transition temperature and the storage elastic modulus were measured. Table 3 shows the measurement results of the glass transition temperature. The storage elastic modulus at 200 ° C. according to the DMA measurement result was 73 MPa.

  In addition, the measurement of the glass transition temperature (Tg) of a film was performed by tensile mode (temperature rising rate of 5 degree-C / min) using TMA (TMA / SS120C by Seiko Instruments Inc.) (hereinafter the same). ).

  Moreover, the storage elastic modulus of the film was measured using a dynamic viscoelasticity measuring apparatus (EXSTAR6000 manufactured by Seiko Instruments Inc.) (the same applies hereinafter).

<< Preparation of Varnish V61 >>
HxNB (0.16 g, 0.897 mmol) and SiX (0.32 g, 1.05 mmol) were weighed and placed in a glass bottle.

  To this monomer solution, IRGANOX 1076 (0.5 g) as a phenolic antioxidant and IRGAFOS 168 (0.125 g) as an organophosphorus antioxidant were added to obtain a monomer antioxidant solution.

In the above polymer P2 solution (6.7 g), monomer antioxidant solution (total amount), and Pd1446 (6.0 × 10 ⁻⁴ g, 4.15 × 10 ⁻⁷ mol, methylene chloride) as a catalyst precursor In 0.1 mL) was added to obtain varnish V61.
This varnish V61 was used after being filtered with a 0.2 μm pore filter.

  And this varnish V61 was apply | coated to the application | coating thickness of 70 micrometers with the doctor blade on the glass substrate, this was set | placed on the hotplate, and it heated at 80 degreeC for 20 minutes, and 150 degreeC for 1 hour, and formed the film.

  Using this film, the glass transition temperature and the storage elastic modulus were measured. Table 3 shows the measurement results of the glass transition temperature. The storage elastic modulus at 250 ° C. according to the DMA measurement result was 80 MPa.

<< Preparation of Varnish V62 >>
SiX (4.8 g, 0.0158 mol) was weighed and placed in a glass bottle.

  To this monomer solution, IRGANOX 1076 (5 g) as a phenol-based antioxidant and IRGAFOS 168 (1.25 g) as an organophosphorus antioxidant were added to obtain a monomer antioxidant solution.

To the polymer P1 solution (30.0 g), as a monomer antioxidant solution (total amount) and [Pd (PCy3) 2H (NCCH3)] tetrakis (pentafluorophenyl) borate (Pd1147) (3 .62 × 10 ⁻³ g, 3.15 × 10 ⁻⁶ mol, in 0.1 mL of methylene chloride) was added to obtain varnish V62.
This varnish V62 was used after being filtered with a 0.2 μm pore filter.

  And this varnish V62 was apply | coated to the coating thickness of 70 micrometers with the doctor blade on the glass substrate, this was set | placed on the hotplate, and it heated at 80 degreeC for 20 minutes, and 150 degreeC for 1 hour, and formed the film.

  Using this film, the glass transition temperature and the storage elastic modulus were measured. Table 3 shows the measurement results of the glass transition temperature. The storage elastic modulus at 250 ° C. according to the DMA measurement result was 67 MPa.

<< Preparation of Varnish V63 >>
TESNB (1.0 g, 0.039 mol) was weighed and placed in a glass bottle.

  To this monomer solution, IRGANOX 1076 (5 g) as a phenol-based antioxidant and IRGAFOS 168 (1.25 g) as an organophosphorus antioxidant were added to obtain a monomer antioxidant solution.

To the above polymer P2 solution (30.0 g), monomer antioxidant solution (total amount), and [Pd (P (iPr) 3) 2 (OCOCH3) (NCCH3)] tetrakis (pentafluorophenyl) as a catalyst precursor ) Borate (Pd1206) (4.07 × 10 ⁻⁴ g, 3.90 × 10 ⁻⁷ mol, in 0.1 mL of methylene chloride) was added to obtain varnish V63.
This varnish V63 was used after being filtered with a filter having a pore size of 0.2 μm.

  And this varnish V63 was apply | coated to the coating thickness of 70 micrometers with the doctor blade on the glass substrate, this was set | placed on the hotplate, and it heated at 80 degreeC for 20 minutes, and 150 degreeC for 1 hour, and formed the film.

  Using this film, the glass transition temperature and the storage elastic modulus were measured. Table 3 shows the measurement results of the glass transition temperature. The storage elastic modulus at 250 ° C. according to the DMA measurement result was 70 MPa.

<< Preparation of Varnish V64 >>
Si ₂ X (2.16 g, 4.67 mmol) was weighed and placed in a glass bottle.

  To this monomer solution, IRGANOX 1076 (0.5 g) as a phenolic antioxidant and IRGAFOS 168 (0.125 g) as an organophosphorus antioxidant were added to obtain a monomer antioxidant solution.

In the polymer P3 solution (30.0 g), monomer antioxidant solution (total amount), and Pd1446 (3.22 × 10 ⁻³ g, 2.23 × 10 ⁻⁶ mol, methylene chloride) as a catalyst precursor Varnish V64 was obtained.
This varnish V64 was used after being filtered with a 0.2 μm pore filter.

  And this varnish V64 was apply | coated to the application | coating thickness of 70 micrometers with the doctor blade on the glass substrate, this was set | placed on the hotplate, and it heated at 80 degreeC for 20 minutes, and 150 degreeC for 1 hour, and formed the film.

  Using this film, the glass transition temperature and the storage elastic modulus were measured. Table 3 shows the measurement results of the glass transition temperature. The storage elastic modulus at 200 ° C. according to the DMA measurement result was 82 MPa.

<< Preparation of Varnish V65 >>
Bis (norbornenemethyl) acetal (NM ₂ X) (3.00 g, 0.104 mol) was weighed and placed in a glass bottle.

  To this monomer solution, IRGANOX 1076 (0.5 g) as a phenolic antioxidant and IRGAFOS 168 (0.125 g) as an organophosphorus antioxidant were added to obtain a monomer antioxidant solution.

In the polymer P3 solution (30.0 g), monomer antioxidant solution (total amount), and Pd1446 (3.33 × 10 ⁻³ g, 2.30 × 10 ⁻⁶ mol, methylene chloride) as a catalyst precursor In 0.1 mL) was added to obtain varnish V65.
This varnish V65 was used after being filtered with a 0.2 μm pore filter.

  And this varnish V65 was apply | coated to the application | coating thickness of 70 micrometers with the doctor blade on the glass substrate, this was set | placed on the hotplate, and it heated at 80 degreeC for 20 minutes, and 150 degreeC for 1 hour, and formed the film.

Using this film, the glass transition temperature and the storage elastic modulus were measured. Table 3 shows the measurement results of the glass transition temperature. The storage elastic modulus at 250 ° C. according to the DMA measurement result was 120 MPa.
The compositions of the varnishes prepared above are summarized in Tables 2 and 3 below.

4). Production and Evaluation of Optical Waveguide Structure 4-1. Fabrication of optical waveguide structure

  As shown below, ten optical waveguide structures of Examples 1 to 14 and Comparative Example were produced.

Example 1
First, varnish V51 as a cladding layer forming material was poured onto a 4-inch thick glass substrate and spread to a substantially constant thickness with a doctor blade.

Next, this was placed on a hot plate and heated at 50 ° C. for 15 minutes, and this was irradiated with UV light using an ultrahigh pressure mercury lamp without a photomask (irradiation amount: 3000 mJ / cm ² , wavelength: 365 nm).

  Subsequently, the lower clad layer was formed by curing using a clean oven at 100 ° C. for 15 minutes and further at 160 ° C. for 1 hour.

  Next, varnish V1 as a core layer forming material was poured onto the surface of the cured lower clad layer and spread to a substantially constant thickness with a doctor blade.

  This was then placed on a hot plate and heated at 45 ° C. for 10 minutes to evaporate the solvent and form a substantially dry solid film.

The film was irradiated with UV light through a photomask (irradiation amount: 3000 mJ / cm ² , wavelength: 365 nm) and then heated on a hot plate at 45 ° C. for 30 minutes, and a linear core pattern appeared.

  The obtained sample was heated in a clean oven at 85 ° C. for 30 minutes and further at 150 ° C. for 60 minutes to obtain a patterned varnish V1 cured layer (core layer).

  Next, the upper clad layer is formed on the core layer in the same manner as the lower clad layer using varnish V51 as a clad layer forming material, and a linear shape having a width of 0.5 cm and a length of 10 cm is formed on the glass substrate. An optical waveguide was obtained.

  In the obtained optical waveguide, the average thickness of the core layer was 50 μm (the width of the core part: 50 μm), and the average thickness of the clad layers (upper and lower parts) was 50 μm.

  Next, this optical waveguide was peeled off from the substrate, and a copper layer (conductor layer) having an average thickness of 45 μm was bonded to each of the both surfaces by a roll laminating method to produce an optical waveguide structure.

(Example 2)
First, varnish V52 as a cladding layer forming material was poured onto a silicon wafer substrate and spread to a substantially constant thickness with a doctor blade.

Next, this was placed on a hot plate and heated at 50 ° C. for 15 minutes, and this was irradiated with UV light using an ultrahigh pressure mercury lamp without a photomask (irradiation amount: 1500 mJ / cm ² , wavelength: 365 nm).

  Then, it further heated at 150 degreeC for 1 hour using clean oven, and created the lower clad layer.

  Next, a varnish V4 of a polyimide precursor is applied as a core layer forming material on the lower clad layer with a bar coater, and heated at 320 ° C. for 1 hour in a nitrogen atmosphere using an oven. did.

  Next, an aluminum layer having a thickness of 0.3 μm was vapor-deposited on the core layer to form a mask layer. Further, a positive photoresist (diazonaphthoquinone-novolak resin system, manufactured by Tokyo Ohka Kogyo Co., Ltd., trade name OFPR-800) was applied on the aluminum layer by spin coating, and then prebaked at about 95 ° C.

  Next, a photomask (Ti) for forming a linear optical waveguide pattern is arranged, irradiated with ultraviolet rays using an ultrahigh pressure mercury lamp, and then developed as a positive resist developer (TMAH: tetramethylammonium hydroxide aqueous solution, Tokyo, Japan). Development was carried out using a product made by Oka, trade name NMD-3).

  Thereafter, post-baking was performed at 135 ° C. Next, the aluminum layer was wet etched to transfer the resist pattern to the aluminum layer.

  Further, the core layer was processed by dry etching using the patterned aluminum layer as a mask.

Next, the linear core part was formed by removing an aluminum layer with an etching liquid.
The core part had a width of 50 μm and a height (average thickness) of 50 μm.

  Next, varnish V52 is poured as a clad layer forming material from above the obtained core part, and an upper clad layer is prepared in the same manner as the lower clad layer. A linear optical waveguide having a length of 10 cm was obtained.

  In the obtained optical waveguide, the average thickness of the cladding layers (upper and lower parts) was 50 μm.

  Next, this optical waveguide was peeled off from the substrate, and a copper layer (conductor layer) having an average thickness of 45 μm was bonded to each of the both surfaces by a roll laminating method to produce an optical waveguide structure.

(Example 3)
First, varnish V53 as a cladding layer forming material was poured onto a glass substrate that had been subjected to a mold release treatment, and spread to a substantially constant thickness with a doctor blade.

Next, this was placed on a hot plate and heated at 50 ° C. for 15 minutes, and this was irradiated with UV light using an ultrahigh pressure mercury lamp without a photomask (irradiation amount: 2500 mJ / cm ² , wavelength: 365 nm).

  Then, it further heated at 150 degreeC for 1 hour using clean oven, and created the lower clad layer.

On top of that, as a core layer forming material, a UV curable epoxy resin (E3135 manufactured by NTT-AT) having a higher refractive index than that of the cladding layer forming material was spin-coated, and then by photolithography using a photomask, The linear core part was directly patterned.
The core part had a width of 35 μm and a height (average thickness) of 35 μm.

  Thereafter, using the same varnish V53 as that for forming the lower clad layer as the clad layer forming material, an upper clad layer is formed in the same manner as the lower clad layer, and a width of 0.5 cm and a length are formed on the glass substrate. A 10 cm linear optical waveguide was obtained.

  In the obtained optical waveguide, the average thickness of the cladding layers (upper part and lower part) was 35 μm.

  Next, this optical waveguide was peeled off from the substrate, and a copper layer (conductor layer) having an average thickness of 45 μm was bonded to each of the both surfaces by a roll laminating method to produce an optical waveguide structure.

(Example 4)
First, varnish V54 was poured as a clad layer forming material on the roughened surface of a copper foil having an average thickness of 18 μm and spread to a substantially constant thickness with a doctor blade.

Next, this was placed on a hot plate and heated and dried at 50 ° C. for 15 minutes, and then irradiated with UV light using an ultrahigh pressure mercury lamp without a photomask (irradiation amount: 3000 mJ / cm ² , wavelength: 365 nm). Thus, a lower clad layer with copper foil was formed. Moreover, the upper clad layer with a copper foil was also prepared by the same material and method.

  On the other hand, the filtered varnish V2 as a core layer forming material was poured onto a quartz glass substrate and spread to a substantially constant thickness with a doctor blade.

  This was then placed on a hot plate and heated at 45 ° C. for 10 minutes to evaporate the solvent and form a substantially dry solid film.

The film was irradiated with UV light through a photomask (irradiation amount: 3000 mJ / cm ² , wavelength: 365 nm) and then heated on a hot plate at 45 ° C. for 30 minutes, and a linear core pattern appeared.

  The obtained sample was heated in a clean oven at 85 ° C. for 30 minutes and further at 150 ° C. for 60 minutes to obtain a patterned varnish V2 cured layer (film).

  The film was peeled from the quartz glass substrate in water, washed with sufficient water, and dried in an oven at 45 ° C. for 1 hour to obtain a single core layer.

  The core layer is sandwiched between the upper and lower clad layers and heated at 150 ° C. for 1 hour while applying a pressure of 10 MPa using an electrothermal press to have a copper layer (conductor layer) on both sides of 0.5 cm in width. A linear optical waveguide structure having a length of 10 cm was obtained.

  In the obtained optical waveguide, the average thickness of the core layer was 35 μm (the width of the core portion: 35 μm), and the average thickness of the clad layers (upper and lower portions) was 35 μm.

(Example 5)
First, varnish V55 was poured as a clad layer forming material onto a release-treated PET film substrate and spread to a substantially constant thickness with a doctor blade.

Next, after placing this on a hot plate and heating and drying at 50 ° C. for 15 minutes, this was irradiated with UV light using an ultrahigh pressure mercury lamp without a photomask (irradiation amount: 2000 mJ / cm ² , wavelength: 365 nm). After that, it was peeled off from the PET film to form a single lower clad layer. A single upper clad layer was also prepared using the same material and method.

  On the other hand, filtered varnish V3 as a core layer forming material was poured onto a quartz glass substrate and spread to a substantially constant thickness with a doctor blade.

  This was then placed on a hot plate and heated at 45 ° C. for 10 minutes to evaporate the solvent and form a substantially dry solid film.

This film was irradiated with UV light through a photomask (irradiation amount: 3000 mJ / cm ² , wavelength: 365 nm) and then heated in a clean oven at 85 ° C. for 30 minutes, and a linear core pattern appeared.

  Furthermore, the cured layer (film) of the varnish V3 patterned by heating at 160 degreeC for 2 hours was obtained.

  The film was peeled from the quartz glass substrate in water, washed with sufficient water, and dried in an oven at 45 ° C. for 1 hour to obtain a single core layer.

  The core layer is sandwiched between the upper and lower clad layers and heated at 150 ° C. for 1 hour while applying a pressure of 6 MPa using an electrothermal press, and a linear light beam having a width of 0.5 cm and a length of 10 cm. A waveguide was obtained.

  In the obtained optical waveguide, the average thickness of the core layer was 50 μm (the width of the core part: 50 μm), and the average thickness of the clad layers (upper and lower parts) was 50 μm.

  Next, a copper layer (conductor layer) having an average thickness of 45 μm was bonded to both surfaces of the optical waveguide by a roll laminating method to produce an optical waveguide structure.

(Example 6)
An optical waveguide structure was obtained in the same manner as in Example 5 except that varnish V56 was used as the cladding layer forming material.

(Example 7)
An optical waveguide structure was obtained in the same manner as in Example 1 except that varnish V57 was used as the cladding layer forming material and varnish V2 was used as the core layer forming material.

(Example 8)
First, varnish V58 was poured as a clad layer forming material onto a release-treated PET film substrate and spread to a substantially constant thickness with a doctor blade.

  Next, this was placed on a hot plate, heated and dried at 50 ° C. for 15 minutes, and then peeled off from the PET film to form a single lower clad layer. A single upper clad layer was also prepared using the same material and method.

  On the other hand, filtered varnish V3 as a core layer forming material was poured onto a quartz glass substrate and spread to a substantially constant thickness with a doctor blade.

  This was then placed on a hot plate and heated at 45 ° C. for 10 minutes to evaporate the solvent and form a substantially dry solid film.

This film was irradiated with UV light through a photomask (irradiation amount: 3000 mJ / cm ² , wavelength: 365 nm) and then heated in a clean oven at 85 ° C. for 30 minutes, and a linear core pattern appeared.

  Furthermore, the cured layer (film) of the varnish V3 patterned by heating at 160 degreeC for 2 hours was obtained.

  The film was peeled from the quartz glass substrate in water, washed with sufficient water, and dried in an oven at 45 ° C. for 1 hour to obtain a single core layer.

  The core layer is sandwiched between the upper and lower clad layers, and heated at 150 ° C. for 1 hour while applying a pressure of 3 MPa using an electrothermal press, and a linear light beam having a width of 0.5 cm and a length of 10 cm. A waveguide was obtained.

  In the obtained optical waveguide, the average thickness of the core layer was 50 μm (the width of the core part: 50 μm), and the average thickness of the clad layers (upper and lower parts) was 50 μm.

  Next, a copper layer (conductor layer) having an average thickness of 45 μm was bonded to both surfaces of the optical waveguide by a roll laminating method to produce an optical waveguide structure.

Example 9
An optical waveguide structure was obtained in the same manner as in Example 4 except that varnish V60 was used as the cladding layer forming material.

(Example 10)
An optical waveguide structure was obtained in the same manner as in Example 4 except that varnish V61 was used as the cladding layer forming material.

(Example 11)
First, varnish V62 as a cladding layer forming material was poured onto a 4-inch thick glass substrate and spread to a substantially constant thickness with a doctor blade.

  Next, this was placed on a hot plate, heated at 50 ° C. for 15 minutes, cured at 80 ° C. for 20 minutes, and then cured at 150 ° C. for 1 hour to form a lower cladding layer.

  Next, varnish V3 as a core layer forming material was poured onto the surface of the cured lower cladding layer and spread to a substantially constant thickness with a doctor blade.

  Thereafter, the coated glass substrate was heated at 45 ° C. for 10 minutes using a hot plate to form a substantially dry solid film.

Next, the solid film formed from varnish V3 is irradiated with UV light (wavelength: 365 nm) through a photomask (irradiation amount: 3000 mJ / cm ² ), aged at room temperature for 30 minutes, and then heated at 85 ° C. for 30 minutes. Then, it was further heated at 150 ° C. for 60 minutes to obtain a core layer.

  In addition, the pattern of the core part was able to be confirmed visually when heated at 85 ° C. for 30 minutes.

  Next, as a cladding layer forming material, varnish V61 was poured onto the surface of the hardened layer formed from varnish V3 and spread to a substantially constant thickness with a spin coater.

  This coated glass substrate is placed on a hot plate and heated at 50 ° C. for 15 minutes, followed by curing at 80 ° C. for 20 minutes and then at 150 ° C. for 1 hour to form an upper cladding layer on the glass substrate. A linear optical waveguide having a width of 0.5 cm and a length of 10 cm was obtained.

  In the obtained optical waveguide, the average thickness of the core layer was 35 μm (the width of the core part: 35 μm), and the average thickness of the clad layers (upper and lower) was 35 μm.

  Next, this optical waveguide was peeled off from the substrate, and a copper layer (conductor layer) having an average thickness of 45 μm was bonded to each of the both surfaces by a roll laminating method to produce an optical waveguide structure.

Example 12
An optical waveguide structure was obtained in the same manner as in Example 11 except that varnish V63 was used as the cladding layer forming material.

(Example 13)
When forming the core layer using varnish V64 as the cladding layer forming material and varnish V1 as the core layer forming material, 45 ° C × 30 minutes prior to heating at 85 ° C. × 30 minutes after UV light irradiation. An optical waveguide structure was obtained in the same manner as in Example 11 except that heating was performed for 30 minutes.

(Example 14)
An optical waveguide structure was obtained in the same manner as in Example 4 except that varnish V65 was used as the cladding layer forming material.

(Comparative example)
First, varnish V59 as a cladding layer forming material was applied on a silicon wafer with a spin coater to a substantially uniform thickness, and then heated in a nitrogen oven at 350 ° C. for 1 hour, thereby forming a lower cladding layer. Formed.

  Next, varnish V1 as a core layer forming material was poured onto the surface of the lower cladding layer and spread to a substantially constant thickness with a doctor blade.

  This was then placed on a hot plate and heated at 45 ° C. for 10 minutes to evaporate the solvent and form a substantially dry solid film.

The film was irradiated with UV light through a photomask (irradiation amount: 3000 mJ / cm ² , wavelength: 365 nm) and then heated on a hot plate at 45 ° C. for 30 minutes, and a linear core pattern appeared.

  The obtained sample was heated in a clean oven at 85 ° C. for 30 minutes and further at 150 ° C. for 60 minutes to obtain a patterned varnish V1 cured layer (core layer).

  Next, as the cladding layer forming material, the same varnish as that used for the lower cladding layer is used, and the upper cladding layer is formed on the core layer in the same manner as the lower cladding layer. A linear optical waveguide having a length of 0.5 cm and a length of 10 cm was obtained.

  In the obtained optical waveguide, the average thickness of the core layer was 50 μm (the width of the core part: 50 μm), and the average thickness of the clad layers (upper and lower parts) was 50 μm.

  Next, this optical waveguide was peeled off from the substrate, and a copper layer (conductor layer) having an average thickness of 45 μm was bonded to each of the both surfaces by a roll laminating method to produce an optical waveguide structure.

4-2. Evaluation 4-2-1. Measurement of light propagation loss

  For each of the optical waveguide structures of Examples and Comparative Examples, the light propagation loss was measured using the “cutback method”.

This is because the light generated from the laser diode is input from one end of the core part through the optical fiber, the output from the other end is measured, and the length of the core part is cut into several lengths. This was done by measuring the light output.
The total optical loss in each length of the core part is expressed by the following formula.

Total optical loss (dB) = -10 log (Pn / Po)
Where Pn is the measured output at the other end of each core portion of length P1, P2,... Pn, and Po is at the end of the optical fiber before coupling the optical fiber to one end of the core portion. This is the measurement output of the light source.

  Next, the total optical loss is plotted as shown in FIG. 14 (Chart 1). The regression line of this data is expressed by the following equation.

y = mx + b
In the formula, m represents a light propagation loss, and b represents a coupling loss.

  In Example 2, light having a wavelength of 1300 nm was used, and in other cases, light having a wavelength of 850 nm was used.

4-2-2. Adhesion test Adhesion tests between the core layer and the clad layer were performed on the optical waveguide structures of the examples and comparative examples.

This was performed by a peel test in which the clad layer was peeled upward 90 ° from the core layer.
The results of measurement of light propagation loss and adhesion test are shown in Table 4 below.

In addition, each numerical value in a table | surface shows an average value of 5 each.
As is clear from Table 4, each of the optical waveguide structures of each example has a small light propagation loss, high optical transmission performance, and high adhesion between the core layer and the cladding layer. It was a thing.

  On the other hand, the optical waveguide structure of the comparative example has a large light propagation loss and a low adhesion force between the core layer and the cladding layer, and is inferior in characteristics. This is probably because the adhesion at the interface between the core layer and the clad layer is poor and peeling occurs in part, and the light propagation loss is also increased.

  Further, after the optical waveguide structures of the examples and comparative examples were exposed to a high humidity environment (60 ° C., 90% RH, 2000 hours), the light propagation loss was measured in the same manner as described above. As a result, almost no change was observed in the optical waveguide structures of each Example before exposure to a high humidity environment. On the other hand, in the optical waveguide structure of the comparative example, a significant increase in light propagation loss was observed.

  Furthermore, the conductor layers of the optical waveguide structures (those before exposure to a high humidity environment) produced in each example and comparative example are patterned to form wirings, and light emitting elements and light receiving elements are formed at predetermined locations. Was mounted to produce a composite device.

  When these composite devices were operated, the composite devices using the optical waveguide structures of the respective examples were faster than the composite devices using the optical waveguide structures of the comparative examples. It was confirmed that operation was possible.

1 is a perspective view (partially cut away) showing an embodiment of an optical waveguide structure of the present 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 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. 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 a chart which shows the change of the total optical loss accompanying the change of the length of a core part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 9 Optical waveguide structure 90 Optical waveguide 91,92 Clad layer 93 Core layer 94 Core part 95 Clad part 901,902 Conductor layer 900 Core layer formation material 910 Layer 915 Polymer 920 Additive 925 Irradiation area 930 Active radiation 935 Mask 9351 Opening 940 Unirradiated region 951, 952 Support substrate 1000 Support substrate 1110 First layer 1120 Second layer 1130 Third layer 2000 Laminate

Claims (46)

A core layer comprising a core portion and a cladding portion having a lower refractive index than the core portion;
An optical waveguide provided in contact with at least one surface of the core layer and having a cladding layer having a refractive index lower than that of the core portion,
The clad layer is composed mainly of a norbornene-based polymer containing a repeating unit of norbornene having an epoxy group and a substituent having an ether structure ,
The norbornene-based polymer is mainly an optical waveguide represented by the following chemical formula 1 .

[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. ] The optical waveguide according to claim 1 , wherein at least a part of the norbornene-based polymer is crosslinked at the epoxy group . The average thickness of the cladding layer, the optical waveguide according to claim 1 or 2 which is 0.1 to 1.5 times the average thickness of the core 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 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 according to any one of claims 1 to 3, wherein the optical waveguide is obtained as the core portion and the other as the cladding 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 according to claim 4 . The first substance includes a compound that generates a cation and a weakly coordinating anion upon irradiation with the active radiation, and the second substance has an activation temperature due to the action of the weakly coordinating anion. The optical waveguide according to claim 4 or 5 , 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 according to any one of claims 4 to 6 . The optical waveguide according to claim 7 , 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 according to claim 7 or 8 , 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. ] The optical waveguide according to claim 9 , wherein p and r are each selected from an integer of 1 or 2. The optical core according to any one of claims 4 to 10, 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. The core layer after heat treatment at said second temperature, according to claim 11 is obtained by heating said layer at said second temperature a third temperature higher than Optical waveguide. The optical waveguide according to claim 12 , wherein the third temperature is 20 ° C. or more higher than the second temperature. The optical waveguide according to claim 4 , wherein the monomer includes a crosslinkable monomer. The optical waveguide according to claim 4 , wherein the monomer is mainly a norbornene-based monomer. The optical waveguide according to claim 14 , 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. The optical waveguide according to claim 4 , 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. The optical waveguide according to claim 17 . 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 a part of the molecular structure can be detached from the main chain by 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. 4. The optical waveguide according to claim 1 , wherein the optical waveguide is one. The optical waveguide according to claim 19 , wherein the core layer is obtained by performing a heat treatment on the layer after the irradiation with the active radiation. The substance includes a compound that generates a cation and a weakly coordinating anion upon irradiation with the actinic radiation, and the leaving group is an acid leaving group that is released by the action of the cation. The optical waveguide according to 19 or 20 . The optical waveguide according to claim 18 or 21 , wherein the acid leaving group has at least one of an -O- structure, an -Si-aryl structure, and an -O-Si- structure. The optical waveguide according to any one of claims 17 to 22, wherein the leaving group causes a decrease in the refractive index of the polymer due to the leaving. The optical waveguide according to claim 23 , wherein the leaving group is at least one of a -Si-diphenyl structure and a -O-Si-diphenyl structure. The optical waveguide according to any one of claims 4 to 24, wherein the active radiation has a peak wavelength in a range of 200 to 450 nm. The dose of the active radiation light waveguide according to any one of claims 4 to 25 is 0.1~9J / cm ^2. The optical waveguide according to any one of claims 4 to 26, wherein the active radiation is applied to the layer through a mask. The optical waveguide according to claim 4 , wherein the layer further contains an antioxidant. The optical waveguide according to any one of claims 4 to 28 , wherein the layer further contains a sensitizer. 30. The optical waveguide according to claim 4 , wherein the polymer is mainly a norbornene-based polymer. The optical waveguide according to claim 30 , 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 according to claim 1 . 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 according to claim 32 , wherein the refractive indexes thereof are different due to different amounts. 34. The light according to claim 33 , wherein the reactant is at least one of a polymer of the norbornene-based monomer, a crosslinked structure that bridges the norbornene-based polymers, and a branched structure that branches from the norbornene-based polymer. Waveguide. The optical waveguide according to claim 33 or 34 , wherein the norbornene-based polymer includes a repeating unit of aralkylnorbornene. The optical waveguide according to claim 33 or 34 , wherein the norbornene-based polymer includes a repeating unit of benzylnorbornene. The optical waveguide according to claim 33 or 34 , wherein the norbornene-based polymer contains 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 from each other in the number of the leaving groups bonded to the main chain, and the content of a reactant of a norbornene monomer having a refractive index different from that of the norbornene polymer. 38. The optical waveguide according to any one of claims 33 to 37, 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 first norbornene-based material and the second norbornene-based materials, by the number of the cleavable groups of the conditions attached to the main chain is different, according to claim 32 in which their refractive index is different Optical waveguide. The optical waveguide according to claim 38 or 39 , wherein the norbornene-based polymer includes a repeating unit of diphenylmethylnorbornenemethoxysilane. 41. The optical waveguide according to claim 33 , wherein the norbornene-based polymer includes a repeating unit of alkyl norbornene. 41. The optical waveguide according to claim 33 , wherein the norbornene-based polymer includes a hexyl norbornene repeating unit. 43. The optical waveguide according to claim 33 , wherein the norbornene-based polymer is an addition polymer. 44. An optical waveguide structure comprising the optical waveguide according to claim 1 and a conductor layer provided on at least one surface side of the optical waveguide. 45. The optical waveguide structure according to claim 44 , wherein an average thickness of the conductor layer is 10 to 90% of an average thickness of the optical waveguide. 46. The optical waveguide structure according to claim 44 or 45 , wherein the conductor layer is formed by at least one of a dry plating method, a wet plating method, and a bonding of a conductive sheet material.

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