Composition for clad, composition set, optical waveguide, and electronic device

Abstract

To provide a composition for a clad from which an optical waveguide having improved thermal reliability can be obtained.SOLUTION: A composition for a core, which is usable in a clad of an optical waveguide, contains a cyclic olefin resin (A), and a phenol compound (B).SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a composition for a cladding, a composition set, an optical waveguide, and an electronic device.

Background Art

[0002] In recent years, in information and communication devices, there has been a demand for components that can achieve more advanced information communication such as increased information capacity and higher information communication speed. As one of such components, optical waveguides have been studied.

[0003] As a technology of an optical waveguide, for example, the technology described in Patent Document 1 can be mentioned.

[0004] Patent Document 1 describes an optical waveguide formed by laminating a core layer made of a polymer and a cladding layer made of a polymer on a substrate, wherein the core layer is sandwiched from a direction parallel to the surface of the substrate by a cladding layer having a refractive index smaller than that of the cladding layer sandwiching the core layer from a direction perpendicular to the surface of the substrate. According to the optical waveguide of Patent Document 1, it is described that an optical waveguide with less polarization dependence can be realized even when using a polymer with high birefringence such as polyimide.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] The present invention provides a composition for a cladding capable of obtaining an optical waveguide with improved thermal reliability.

Means for Solving the Problems

[0007] According to the present invention, there are provided a clad composition, a composition set, an optical waveguide, and an electronic device shown below.

[0008] [1] A clad composition capable of being used for a clad of an optical waveguide, comprising a cyclic olefin resin (A) and a phenol compound (B), the clad composition. [2] The clad composition according to [1], wherein the cyclic olefin resin (A) is an alkali-soluble resin. [3] The clad composition according to [1] or [2], wherein the cyclic olefin resin (A) contains a norbornene resin. [4] The clad composition according to any one of [1] to [3], wherein the cyclic olefin resin (A) has an acidic group. [5] The clad composition according to any one of [1] to [4], wherein the cyclic olefin resin (A) contains a structural unit represented by the following formula (1).

Chemical formula

Chemical formula

[10] The melting point of the phenol compound (B) is 50°C or more and 150°C or less, and the clad composition according to any one of [1] to [9] above.

[11] The phenol compound (B) contains a phenol compound (B1) having a substituent containing an aliphatic hydrocarbon group, and the clad composition according to any one of [1] to

[10] above.

[12] The hydroxyl equivalent of the phenol compound (B1) having a substituent containing an aliphatic hydrocarbon group is 150 g / eq or more and 250 g / eq or less, and the clad composition according to

[11] above.

[13] The content of the phenol compound (B) in the clad composition is 0.5 part by mass or more and 30 parts by mass or less when the content of the cyclic olefin resin (A) in the clad composition is 100 parts by mass, and the clad composition according to any one of [1] to

[12] above.

[14] The clad composition according to any one of [1] to

[13] above, further comprising an epoxy compound (C).

[15] The clad composition according to any one of [1] to

[14] above, further comprising a photoacid generator (D).

[16] The clad composition according to any one of [1] to

[15] above, further comprising an organic solvent (E).

[17] The clad composition according to any one of [1] to

[16] , which is in a varnish state.

[18] The clad composition according to any one of [1] to

[17] , having a refractive index of 1.470 or more and 1.530 or less at 30 °C and a wavelength of 1310 nm.

[19] The clad composition according to any one of [1] to

[18] , having an absorbance of 0.040 or more and 0.080 or less at 22 °C and a wavelength of 1310 nm.

[20] The clad composition according to any one of [1] to

[19] , and a core composition that can be used for the core of an optical waveguide, comprising a composition set.

[21] The composition set according to

[20] , wherein the core composition includes a polyimide resin and a polyfunctional (meth)acrylate.

[22] An optical waveguide comprising a clad made of the clad composition according to any one of [1] to

[19] .

[23] Comprising a silicon photonics device, The silicon photonics device includes the optical waveguide according to

[22] , an electronic device. [Advantages of the Invention]

[0009] According to the present invention, it is possible to provide a clad composition capable of obtaining an optical waveguide with improved thermal reliability. [Brief Description of the Drawings]

[0010]

Figure 1

[0011] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the drawings are schematic and do not match the actual dimensional ratios. The numerical range "A to B" represents A or more and B or less unless otherwise specified. (Meth)acrylate is a concept including both acrylate and methacrylate. Further, the (meth)acryloyl group is a concept including both the acryloyl group and the methacryloyl group.

[0012] The optical waveguide may be formed, for example, on a chip (e.g., a silicon chip or the like). Since the chip may generate heat, the optical waveguide formed on the chip may be required to have thermal reliability. Here, in this specification, high thermal reliability of the optical waveguide means that when an environmental test (e.g., under the conditions of 125°C for 1000 hours) is performed on the optical waveguide, the difference between the propagation loss of the optical waveguide after the environmental test and the propagation loss of the optical waveguide before the environmental test is small.

[0013] The present invention provides a cladding composition capable of obtaining an optical waveguide with improved thermal reliability.

[0014] [Cladding Composition] The cladding composition of the present embodiment is a cladding composition that can be used for the cladding of an optical waveguide, and includes a cyclic olefin resin (A) and a phenol compound (B).

[0015] The refractive index of the cladding composition of the present embodiment at 30°C and a wavelength of 1310 nm is preferably 1.530 or less, more preferably 1.520 or less, and still more preferably 1.510 or less from the viewpoint of further improving the optical propagation efficiency of the optical waveguide. The lower limit value is not particularly limited, and may be, for example, 1.470 or more, or 1.480 or more. Here, the refractive index of the cladding composition at 30°C and a wavelength of 1310 nm means the value of the refractive index calculated by the method described in the examples.

[0016] The absorbance of the clad composition of the present embodiment at 22°C and a wavelength of 1310 nm is preferably 0.080 or less, more preferably 0.070 or less, still more preferably 0.065 or less, and the lower limit is not particularly limited, but may be, for example, 0.040 or more, or may be 0.050 or more. Here, the absorbance of the clad composition at 22°C and a wavelength of 1310 nm means the value of the absorbance calculated by the method described in the examples.

[0017] The shape of the clad composition of the present embodiment is not particularly limited, and may be, for example, a varnish shape, a film shape, a film shape, a sheet shape, etc., but preferably a varnish shape.

[0018] Hereinafter, each constituent of the clad composition of the present embodiment will be described.

[0019] <Cyclic olefin resin (A)> The clad composition of the present embodiment contains a cyclic olefin resin (A). The cyclic olefin resin (A) is not particularly limited as long as it is a resin containing a structural unit derived from a cyclic olefin, but preferably contains a norbornene resin.

[0020] The cyclic olefin resin (A) preferably has an acidic group. The acidic group means a substituent showing acidity. The acidic group contains at least one selected from the group consisting of, for example, a carboxy group, a phenolic hydroxyl group, -C(OH)-(CF3)2, and -N(H)-S(O)2-CF3, and preferably contains at least one selected from the group consisting of a carboxy group and -C(OH)-(CF3)2.

[0021] The amount of the acidic group in the cyclic olefin resin (A) is preferably 0.001 mol or more and 0.01 mol or less, more preferably 0.0015 mol or more and 0.006 mol or less per 1 g of the polymer.

[0022] The cyclic olefin resin (A) preferably contains a structural unit containing a group having an alkyl ether structure, more preferably contains a structural unit represented by the formula (1).

[0023]

Chemical formula

[0024] In the formula (1), z is an integer of 1 or more and 10 or less, preferably an integer of 1 or more and 5 or less, more preferably an integer of 1 or more and 3 or less, and still more preferably 2.

[0025] When the total of all the structural units in the cyclic olefin resin (A) is 100 mol%, the content of the structural unit represented by the formula (1) in the cyclic olefin resin (A) is preferably 20 mol% or more and 70 mol% or less, more preferably 30 mol% or more and 65 mol% or less.

[0026] The cyclic olefin resin (A) preferably contains a structural unit represented by the formula (2).

[0027]

Chemical formula

[0028] In the formula (2), x is an integer of 0 or more and 10 or less, preferably an integer of 0 or more and 5 or less, more preferably an integer of 1 or more and 3 or less, and still more preferably 1.

[0029] When the total of all the structural units in the cyclic olefin resin (A) is 100 mol%, the content of the structural unit represented by the formula (2) in the cyclic olefin resin (A) is preferably 10 mol% or more and 60 mol% or less, more preferably 20 mol% or more and 50 mol% or less.

[0030] The cyclic olefin resin (A) preferably contains a structural unit represented by the formula (3).

[0031]

Chemical formula

[0032] In formula (3), y is an integer of 0 or more and 10 or less, preferably an integer of 1 or more and 5 or less, more preferably an integer of 1 or more and 3 or less, and still more preferably 2.

[0033] When the total of all structural units in the cyclic olefin resin (A) is 100 mol%, the content of the structural unit represented by formula (3) in the cyclic olefin resin (A) is preferably 5 mol% or more and 50 mol% or less, more preferably 10 mol% or more and 40 mol% or less.

[0034] When the total of all structural units in the cyclic olefin resin (A) is 100 mol%, the total content of the structural unit represented by formula (2) and the structural unit represented by formula (3) in the cyclic olefin resin (A) is preferably 20 mol% or more and 70 mol% or less, more preferably 30 mol% or more and 65 mol% or less.

[0035] The cyclic olefin resin (A) preferably contains a structural unit represented by formula (1), a structural unit represented by formula (2), and a structural unit represented by formula (3). That is, the cyclic olefin resin (A) is preferably represented by formula (4).

[0036]

Chemical formula

[0037] In formula (4), l, m, and n are each an integer of 1 or more and 98 or less, and l + m + n = 100. In formula (4), l is preferably an integer of 10 or more and 60 or less, more preferably an integer of 20 or more and 50 or less. In formula (4), m is preferably an integer of 5 or more and 50 or less, more preferably an integer of 10 or more and 40 or less. In formula (4), n is preferably an integer of 20 or more and 70 or less, more preferably an integer of 30 or more and 65 or less. In formula (4), x has the same meaning as x in formula (2), y has the same meaning as y in formula (3), and z has the same meaning as z in formula (1). Note that the cyclic olefin resin represented by formula (4) may be a random copolymer or a block copolymer.

[0038] In formula (4), the degree of polymerization of the structural unit represented by formula (1) with respect to the degrees of polymerization of the structural unit represented by formula (2) and the structural unit represented by formula (3) (that is, n / (l + m)) is preferably 0.3 or more and 2.0 or less, more preferably 0.4 or more and 1.7 or less.

[0039] The cyclic olefin resin (A) is preferably an alkali-soluble resin.

[0040] The weight average molecular weight (Mw) of the cyclic olefin resin (A) is preferably 5,000 or more and 500,000 or less, more preferably 7,000 or more and 200,000 or less, still more preferably 8,000 or more and 100,000 or less. The weight average molecular weight (Mw) of the cyclic olefin resin can be measured using gel permeation chromatography (GPC) in accordance with ASTM DS3536-91, using a standard cyclic olefin resin.

[0041] When the content of the cyclic olefin resin (A) in the clad composition of the present embodiment is 100% by mass of the total solid content in the clad composition, it is preferably 20% by mass or more, more preferably 30% by mass or more, still more preferably 40% by mass or more, still more preferably 50% by mass or more, and preferably 80% by mass or less, more preferably 70% by mass or less, still more preferably 60% by mass or less. Here, in this specification, the total solid content in the composition means all components that remain as solid components in the cured product composed of the composition.

[0042] The cyclic olefin resin (A) can be produced, for example, by a known method. More specifically, it can be produced by polymerizing monomers capable of forming each structural unit by any method.

[0043] The cyclic olefin resin (A) may be a single type of cyclic olefin resin or may contain two or more types of cyclic olefin resins.

[0044] <Phenol compound (B)> The clad composition of this embodiment contains a phenol compound (B).

[0045] The phenol compound (B) preferably contains at least one selected from the group consisting of a phenol compound (B1) having a substituent containing an aliphatic hydrocarbon group and a phenol compound having a plurality of phenol skeletons, and more preferably contains a phenol compound (B1) having a substituent containing an aliphatic hydrocarbon group.

[0046] The phenol compound (B1) having a substituent containing an aliphatic hydrocarbon group is preferably a phenol compound having a substituent having an alkyl chain ((-CH2-) n ). The alkyl chain ((-CH2-) n ) preferably has an n value of 1 or more and 8 or less, more preferably 2 or more and 6 or less, and still more preferably 3 or more and 5 or less. The substituent containing an aliphatic hydrocarbon group is, for example, a substituent containing at least one selected from the group consisting of a methylene group, an ethylene group, a trimethylene group, a butyl group, a 2,2-dimethylbutyl group, a hexyl group, etc., and preferably contains at least one selected from the group consisting of a butyl group and a hexyl group.

[0047] The hydroxyl equivalent of the phenol compound (B1) having a substituent containing an aliphatic hydrocarbon group is preferably 150 g / eq or more and 250 g / eq or less, more preferably 160 g / eq or more and 240 g / eq or less, and still more preferably 180 g / eq or more and 230 g / eq or less.

[0048] The hydroxyl equivalent of the phenol compound can be measured by a method of titrating a solution in which the phenol compound is mixed in a standard alkali solution.

[0049] The phenol compound having a plurality of phenol skeletons may have either a linked polycyclic structure in which the phenol skeletons are linked by single bonds and not directly bonded to each other, or a condensed (fused) polycyclic structure in which the phenol skeletons are directly bonded to each other without a single bond in between, but preferably a linked polycyclic structure.

[0050] The hydroxyl equivalent of the phenol compound having a plurality of phenol skeletons is preferably 50 g / eq or more and 180 g / eq or less, more preferably 60 g / eq or more and 150 g / eq or less, still more preferably 70 g / eq or more and 130 g / eq or less, and even more preferably 90 g / eq or more and 110 g / eq or less.

[0051] Further, the phenol compound (B) preferably has a structure derived from benzoic acid. The structure derived from benzoic acid is preferably a structure derived from any one selected from the group consisting of monohydroxybenzoic acids such as benzoic acid, 2-hydroxybenzoic acid, and 3-hydroxybenzoic acid; dihydroxybenzoic acids such as 2,4-dihydroxybenzoic acid; and the like.

[0052] The phenolic compound (B) specifically includes, for example, 4-(1,1-dimethylpropyl)phenol, 4-cyclohexylphenol, 4-(1,1,3,3-tetramethylbutyl)phenol, 4-(4-hydroxyphenyl)-2-butanone, 4'-hydroxybutyrophenone, 4'-hydroxyvalerophenone, 4'-hydroxyhexanophenone, 3-(4-hydroxyphenyl)propionic acid, methyl 3-hydroxybenzoate, ethyl 3-hydroxybenzoate, methyl 4-hydroxybenzoate, ethyl 4-hydroxybenzoate, propyl 4-hydroxybenzoate, isopropyl 4-hydroxybenzoate, butyl 4-hydroxybenzoate, isobutyl 4-hydroxybenzoate, hexyl 4-hydroxybenzoate, benzyl 4-hydroxybenzoate, 1,3-bis[2-(4-hydroxyphenyl)-2-propyl]benzene, BisP-DED (manufactured by Honshu Chemical Industry Co., Ltd.), etc., and preferably includes at least one selected from the group consisting of propyl 4-hydroxybenzoate, methyl 4-hydroxybenzoate, butyl 4-hydroxybenzoate, and hexyl 4-hydroxybenzoate.

[0053] The melting point of the phenolic compound (B) is preferably 50°C or higher and 150°C or lower, more preferably 55°C or higher and 140°C or lower, and even more preferably 60°C or higher and 130°C or lower. When the phenolic compound (B) contains two or more phenolic compounds, at least one phenolic compound may be within the above range.

[0054] The phenolic compound (B) more preferably includes a phenolic compound having a melting point of 50°C or higher and 150°C or lower and a phenolic compound having a melting point of 151°C or higher. The melting point of the phenolic compound having a melting point of 151°C or higher is preferably 151°C or higher and 250°C or lower, and more preferably 181°C or higher and 230°C or lower.

[0055] When the content of the phenolic compound (B) in the clad composition of the present embodiment is based on 100 parts by mass of the cyclic olefin resin (A) in the clad composition, it is preferably 0.5 parts by mass or more and 30 parts by mass or less, more preferably 3 parts by mass or more and 27 parts by mass or less, still more preferably 5 parts by mass or more and 23 parts by mass or less, and even more preferably 10 parts by mass or more and 20 parts by mass or less.

[0056] The phenolic compound (B) may be a single phenolic compound or may contain two or more phenolic compounds.

[0057] <Epoxy compound (C)> The clad composition of the present embodiment preferably further contains an epoxy compound (C). The epoxy compound (C) has a function of crosslinking the cyclic olefin resin (A).

[0058] The epoxy compound (C) is not particularly limited and may contain an aliphatic epoxy compound or may contain an aromatic epoxy compound. From the viewpoint of more appropriately adjusting the crosslinking density of the cyclic olefin resin (A), it preferably contains an aliphatic epoxy compound.

[0059] The epoxy compound (C) preferably contains two or more glycidyl groups in the molecule, and more preferably contains three or more and nine or less glycidyl groups in the molecule.

[0060] The epoxy compound (C) preferably contains at least one selected from the group consisting of trimethylolpropane triglycidyl ether, 1,6 - hexanediol diglycidyl ether, polypropylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, polytetramethylene glycol diglycidyl ether, and hydrogenated bisphenol A diglycidyl ether.

[0061] When the content of the epoxy compound (C) in the clad composition of the present embodiment is based on 100 parts by mass of the content of the cyclic olefin resin (A) in the clad composition, it is preferably 1 part by mass or more and 100 parts by mass or less, more preferably 5 parts by mass or more and 50 parts by mass or less, and still more preferably 10 parts by mass or more and 30 parts by mass or less.

[0062] The epoxy compound (C) may be a single epoxy compound or may contain two or more epoxy compounds.

[0063] <Photoacid generator (D)> The clad composition of the present embodiment preferably further contains a photoacid generator (D).

[0064] The photoacid generator (D) is not particularly limited. For example, it contains at least one selected from the group consisting of onium salts, halogenated organic compounds, quinonediazide compounds, α,α-bis(sulfonyl)diazomethane-based compounds, α-carbonyl-α-sulfonyl-diazomethane-based compounds, sulfone compounds, organic acid ester compounds, organic acid amide compounds, and organic acid imide compounds, etc., and preferably contains a quinonediazide compound.

[0065] When the content of the photoacid generator (D) in the clad composition of the present embodiment is based on 100 parts by mass of the content of the cyclic olefin resin (A) in the clad composition, it is preferably 1 part by mass or more and 50 parts by mass or less, more preferably 5 parts by mass or more and 40 parts by mass or less, and still more preferably 10 parts by mass or more and 30 parts by mass or less.

[0066] The photoacid generator (D) may be a single photoacid generator or may contain two or more photoacid generators.

[0067] <Organic solvent (E)> The clad composition of the present embodiment preferably further contains an organic solvent (E). When the clad composition contains an organic solvent (E), a varnish-like clad composition can be obtained.

[0068] The organic solvent (E) contains at least one selected from the group consisting of, for example, acetone, methyl ethyl ketone, toluene, propylene glycol methyl ethyl ether, propylene glycol dimethyl ether, propylene glycol 1-methyl ether 2-acetate, diethylene glycol ethyl methyl ether, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, benzyl alcohol, propylene carbonate, ethylene glycol diacetate, propylene glycol diacetate, propylene glycol monomethyl ether acetate, dipropylene glycol methyl-n-propyl ether, butyl acetate, γ-butyrolactone, methyl lactate, ethyl lactate, butyl lactate, and the like.

[0069] When the composition for cladding contains the organic solvent (E), the concentration of the total solid content of the composition for cladding is preferably 10% by mass or more and 50% by mass or less, more preferably 20% by mass or more and 45% by mass or less. When the concentration of the total solid content of the composition for cladding is within the above range, each component can be sufficiently dissolved or dispersed, the coating property of the composition can be further improved, and furthermore, the viscosity of the composition can be appropriately controlled.

[0070] The organic solvent (E) may be a single organic solvent or may contain two or more organic solvents.

[0071] <Antioxidant> The composition for cladding of the present embodiment preferably further contains an antioxidant. The antioxidant is not particularly limited and includes, for example, at least one selected from the group consisting of phenolic antioxidants, amine antioxidants, phosphorus antioxidants, and thioether antioxidants, and preferably includes phenolic antioxidants and amine antioxidants.

[0072] When the content of the cyclic olefin resin (A) in the clad composition of this embodiment is 100 parts by mass, the content of the antioxidant in the clad composition is preferably 0.1 part by mass or more and 50 parts by mass or less, more preferably 5 parts by mass or more and 40 parts by mass or less, and still more preferably 10 parts by mass or more and 30 parts by mass or less.

[0073] The antioxidant may be a single antioxidant or may contain two or more antioxidants.

[0074] <Other components> The clad composition of this embodiment may further contain other components. Examples of other components include sensitizers, fillers such as silica, defoamers, leveling agents, crosslinking aids, and the like. The content of other components is an appropriate amount.

[0075] When the total content of the cyclic olefin resin (A) and the phenol compound (B) in the clad composition of this embodiment is 100% by mass of all components in the clad composition, it is preferably 10% by mass or more and 50% by mass or less, more preferably 15% by mass or more and 40% by mass or less, and still more preferably 20% by mass or more and 30% by mass or less.

[0076] When the total content of the cyclic olefin resin (A) and the phenol compound (B) in the clad composition of this embodiment is 100% by mass of all solid components in the clad composition, it is preferably 40% by mass or more and 95% by mass or less, more preferably 50% by mass or more and 85% by mass or less, and still more preferably 55% by mass or more and 75% by mass or less.

[0077] The clad composition of this embodiment can be obtained, for example, by mixing each component.

[0078] [Composition set] The composition set of this embodiment includes the clad composition of this embodiment and a core composition that can be used for the core of an optical waveguide.

[0079] The core composition of the present embodiment is not particularly limited as long as it can be used for the core of an optical waveguide. For example, it may be a resin composition containing a resin used for the core of a known optical waveguide.

[0080] The shape of the core composition of the present embodiment is not particularly limited. For example, it may be in the form of a varnish, film, sheet, etc., but preferably it is in the form of a varnish.

[0081] The core composition of the present embodiment preferably contains a polyimide resin and a polyfunctional (meth)acrylate. When the total content of the polyimide resin and the polyfunctional (meth)acrylate in the core composition of the present embodiment is based on 100% by mass of all components in the core composition, it is preferably 10% by mass or more and 50% by mass or less, more preferably 15% by mass or more and 40% by mass or less, still more preferably 20% by mass or more and 30% by mass or less. When the total content of the polyimide resin and the polyfunctional (meth)acrylate in the core composition of the present embodiment is based on 100% by mass of all solid components in the core composition, it is preferably 60% by mass or more and 95% by mass or less, more preferably 70% by mass or more and 90% by mass or less, still more preferably 75% by mass or more and 85% by mass or less.

[0082] The polyimide resin contained in the core composition of the present embodiment is not particularly limited, but preferably contains a fluorine atom in the molecule.

[0083] The polyfunctional (meth)acrylate contained in the core composition of the present embodiment means a (meth)acrylate compound having two or more (meth)acryloyl groups in one molecule. The polyfunctional (meth)acrylate of the present embodiment preferably contains a (meth)acrylate compound having 5 or more functional groups and a (meth)acrylate compound having 2 or more and 4 or less functional groups.

[0084] The core composition of the present embodiment can be obtained, for example, by mixing each component.

[0085] [Optical waveguide] The optical waveguide of this embodiment includes a cladding made of the cladding composition of this embodiment.

[0086] FIG. 1 is a cross-sectional view schematically showing an example of the structure of the optical waveguide of this embodiment. An example of the optical waveguide of this embodiment will be described with reference to FIG. 1. In FIG. 1, an optical waveguide 100 is formed on a wafer 50. The optical waveguide 100 includes an undercladding 10, a core 20, and an overcladding 30.

[0087] <Core> The material constituting the core 20 is not particularly limited. For example, a material for forming the core of a known optical waveguide can be used, which may be an organic material or an inorganic material.

[0088] The core 20 may be composed of, for example, the core composition in the composition set of this embodiment. The core composition for forming the core may be a cured product, a semi-cured product, or an uncured product, but preferably a cured product.

[0089] The thickness and line width of the core 20 are not particularly limited, but are preferably dimensions that satisfy the single-mode condition. The single-mode condition depends on the relative refractive index difference between the core and the cladding and the guided wavelength, but the thickness and line width of the core 20 are preferably 1 μm or more and 11 μm or less, more preferably 2 μm or more and 10 μm or less.

[0090] <Cladding> The undercladding 10 and the overcladding 30 will be described. Hereinafter, when simply referred to as "cladding", unless otherwise specified, it means a concept including both the undercladding 10 and the overcladding 30.

[0091] At least one selected from the group consisting of the undercladding 10 and the overcladding 30 is made of the cladding composition of this embodiment. As a preferred embodiment, there is an embodiment in which both the underclad 10 and the overclad 30 are made of the clad composition of the present embodiment. Also, as another preferred embodiment, there is an embodiment in which the overclad 30 is made of the clad composition of the present embodiment and the underclad 10 is made of a material other than the clad composition of the present embodiment.

[0092] The clad composition for forming the clad may be a cured product, a semi-cured product, or an uncured product, but is preferably a cured product.

[0093] As a material constituting the clad other than the clad composition of the present embodiment, for example, a material for forming a clad of a known optical waveguide can be used, and it may be an organic material or an inorganic material. The clad may be composed of, for example, SiO2.

[0094] The thickness of the underclad 10 is not particularly limited, but is preferably 1 μm or more and 25 μm or less, more preferably 3 μm or more and 20 μm or less, and still more preferably 5 μm or more and 15 μm or less. The thickness of the overclad 30 from the surface of the underclad 10 is not particularly limited, but is preferably 3 μm or more and 50 μm or less, more preferably 5 μm or more and 40 μm or less, and still more preferably 10 μm or more and 30 μm or less. The thickness of the overclad 30 from the surface of the core 20 is not particularly limited, but is preferably 1 μm or more and 25 μm or less, more preferably 3 μm or more and 20 μm or less, and still more preferably 5 μm or more and 15 μm or less.

[0095] The optical waveguide 100 may further include a configuration other than the underclad 10, the core 20, and the overclad 30.

[0096] The manufacturing method of the optical waveguide 100 is not particularly limited, but includes, for example, the following steps (i) to (iii). (i) Apply a varnish-like clad composition onto the wafer 50, dry it to form an underclad layer, and cure the resulting underclad layer to form the underclad 10. (ii) Apply a varnish-like core composition onto the underclad 10, dry it to form a core layer, and cure the resulting core layer to form the core 20. (iii) Apply a varnish-like clad composition onto the core 20, dry it to form an overclad layer, and cure the resulting overclad layer to form the overclad 30. The method of applying the varnish-like composition is not particularly limited. For example, the spin coating method can be used.

[0097] [Electronic device] The electronic device of this embodiment includes the optical waveguide of this embodiment, preferably includes a silicon photonics device, and the silicon photonics device includes the optical waveguide of this embodiment. Here, silicon photonics is a technology for integrating elements such as optical waveguides, optical switches, optical modulators, and light receivers on a silicon wafer, and a silicon photonics device means a device that utilizes silicon photonics technology.

[0098] The silicon photonics device is, for example, as shown in FIG. 1, a device in which an optical waveguide 100 is formed on a wafer 50. At this time, the wafer 50 is a silicon wafer. The silicon photonics device may further include, for example, Si wire waveguides or the like.

[0099] The electronic devices of this embodiment include electronic devices such as mobile phones, game machines, router devices, WDM devices, personal computers, televisions, and home servers.

[0100] As described above, the embodiments of the present invention have been described, but these are examples of the present invention, and various configurations other than the above can also be adopted. Furthermore, the present invention is not limited to the foregoing embodiments, and modifications, improvements, etc. within the scope that can achieve the object of the present invention are included in the present invention.

Example

[0101] Hereinafter, this embodiment will be described in detail based on examples and comparative examples. Note that this embodiment is not limited to the descriptions of these examples at all.

[0102] [Raw materials] [Synthesis of cyclic olefin resin (A-1)] A plurality of glass apparatuses were prepared and dried at 60 ° C and 0.1 Torr for 18 hours. Then, all the glass apparatuses were installed in a glove box.

[0103] Next, toluene (992 g), dimethoxyethane (116 g), 1,1-bis(trifluoromethyl)-2-(bicyclo[2.2.1]hept-2-en-5-yl)ethyl alcohol (hereinafter, HFANB) (148 g, 0.54 mol), ethyl-3-(bicyclo[2.2.1]hept-2-en-2-yl)propanoate (hereinafter, EPEsNB) (20.7 g, 0.107 mol), 5-((2-(2-methoxyethoxy)ethoxy)methyl)bicyclo[2.2.1]hept-2-ene (hereinafter, NBTON) (61.9 g, 0.274 mol) were charged into one glass apparatus (glass apparatus X) to obtain a mixture containing each monomer. Then, this mixture was purged (nitrogen purge) by flowing nitrogen for 30 minutes while heating at 45 °C.

[0104] Also, in another glass device (glass device Y), EPEsNB (14.2 g, 0.073 mol) and NBTON (46.7 g, 0.159 mol) were mixed and purged with nitrogen. After the nitrogen purge was completed, bis(toluene)bis(perfluorophenyl)nickel (5.82 g, 0.012 mol) dissolved in 60.5 ml of toluene was added into glass device Y. At the same time, the mixture in the aforementioned glass device X was added into glass device Y over 3 hours at a rate such that the polymerization reaction proceeded at a certain level to obtain a reaction solution.

[0105] Next, the unreacted monomers in the reaction solution were removed by dissolving the reaction solution in about 1 L of a methanol / tetrahydrofuran (THF) (= 4 mol / 5 mol) solution. Next, the esters in the reaction solution were hydrolyzed with a sodium hydroxide solution of sodium hydroxide / sodium acetate (= 4.8 mol / 1 mol) at 60 °C for 4 hours to obtain solution A. Thereafter, methanol (405 g), THF (87 g), acetic acid (67 g), formic acid (67 g), and deionized water (21 g) were added to solution A and stirred at 50 °C for 15 minutes. When the stirring was stopped, solution A separated into an aqueous layer and an organic layer, so the upper aqueous layer was removed, and the organic layer was washed 3 times with a methanol / deionized water (= 390 g / 2376 g) solution at 60 °C for 15 minutes. Then, the obtained polymer was diluted in propylene glycol methyl ether acetate and the solvent was replaced so that the polymer concentration became 40%. In this way, a polymer (cyclic olefin resin (A-1)) in a solution state was obtained.

[0106] The yield of the cyclic olefin resin (A-1) was 93.1%. The weight average molecular weight (Mw) of the cyclic olefin resin (A-1) was 85,900. The molecular weight distribution (PD) of the cyclic olefin resin (A-1) was 2.52.

[0107] Also, the composition of the cyclic olefin resin (A-1) was 1 In 1H-NMR, HFANB was 45.0 mol%, 2-(bicyclo[2.2.1]hept-2-en-5-yl)propionic acid was 15.0 mol%, and NBTON was 40.0 mol%. The cyclic olefin resin (A-1) is represented by the following formula (A-1).

[0108] [ka]

[0109] In formula (A-1), l:m:n=45:15:40.

[0110] <Synthesis of Cyclic Olefin Resin (A-2)> Cyclic olefin resin (A-2) represented by the following formula (A-2) was synthesized in the same manner as in the above <Synthesis of cyclic olefin resin (A-1)>.

[0111] [ka]

[0112] In formula (A-2), l:m:n=25:15:60.

[0113] <Synthesis of Cyclic Olefin Resin (A-3)> A cyclic olefin resin (A-3) represented by the following formula (A-3) was synthesized in the same manner as in the above <Synthesis of cyclic olefin resin (A-1)>.

[0114] [ka]

[0115] In formula (A-3), l:m:n=25:35:40.

[0116] Details of the raw materials for each component in Table 1 are as follows:

[0117] <Cyclic olefin resin (A)> (A-1) Cyclic olefin resin synthesized above (A-2) Cyclic olefin resin synthesized above (A-3) Cyclic olefin resin synthesized above

[0118] <Phenolic compound (B)> (B-1) Butyl 4-hydroxybenzoate (a phenolic compound having a substituent containing an aliphatic hydrocarbon group, melting point: 70 °C, weight average molecular weight (Mw): 194, hydroxyl equivalent: 194 g / eq) (B-2) Hexyl 4-hydroxybenzoate (a phenolic compound having a substituent containing an aliphatic hydrocarbon group, melting point: 53 °C, weight average molecular weight (Mw): 222, hydroxyl equivalent: 222 g / eq) (B-3) 2,2'-Dihydroxydiphenylmethane (a phenolic compound having a plurality of phenolic skeletons, melting point: 120 °C, weight average molecular weight (Mw): 200, hydroxyl equivalent: 100 g / eq) (B-4) 4,4'-[(2-Hydroxyphenyl)methylene]bis[2-cyclohexyl-5-methylphenol] (a phenolic compound having a plurality of phenolic skeletons, melting point: 222 °C, weight average molecular weight (Mw): 484, hydroxyl equivalent: 161 g / eq)

[0119] <Epoxy compound (C)> (C-1) A compound represented by the following formula (C-1)

[0120]

Chemical formula

[0121] <Photoacid generator (D)> (D-1) A compound represented by the following formula (D-1)

[0122]

Chemical formula

[0123] <Organic solvent (E)> (E-1) Propylene glycol methyl ether acetate (PGMEA)

[0124] <Antioxidant> (F-1) 4,4'-Di(α,α-dimethylbenzyl)diphenylamine (F-2) 2,6-bis[(2-hydroxy-5-methylphenyl)methyl]-4-methylphenol

[0125] [Examples 1 to 6] The raw materials formulated according to Table 1 were mixed to obtain varnish-like clad compositions of Examples 1 to 6. In Table 1, the parts by mass of the cyclic olefin resin are parts by mass of the solid content. The parts by mass of the organic solvent PGMEA are parts by mass including the PGMEA contained in the cyclic olefin resin solution. Hereinafter, the compositions of Examples 1 to 6 may also be referred to as compositions A to F, respectively.

[0126] Examples and comparative examples of optical waveguides will be described below. First, the production of compositions G and H, which are raw materials for the optical waveguides, will be described.

[0127] <Production of Composition G> (Synthesis of polyimide resin 1) A 3-L glass separable flask equipped with a stirrer and a stirring blade was charged with 64.1 g (0.20 mol) of 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl (TFMB), 97.7 g (0.22 mol) of 4,4'-(hexafluoroisopropylidene)diphthalic dianhydride (6FDA), and 500 g of dimethylacetamide (DMAc). The mixture was stirred to dissolve TFMB and 6FDA in the DMAc. The mixture was then stirred under a nitrogen stream at room temperature for 12 hours to polymerize the mixture, yielding a polyamic acid solution.

[0128] After adding 16 g of pyridine to the obtained polyamic acid solution, 82 g of acetic anhydride was added dropwise at room temperature, and then the liquid temperature was kept at 20 to 100°C and stirring was continued for 24 hours to carry out the imidization reaction, thereby obtaining a polyimide solution.

[0129] The resulting polyimide solution was poured into 1,000 g of methanol in a 5 L container while stirring to precipitate a polyimide resin. The solid polyimide resin was then filtered using a suction filter and washed with 1,000 g of methanol. The solid was then dried at 100°C for 24 hours using a vacuum dryer, and then further dried at 200°C for 3 hours. This resulted in the production of polyimide resin 1, a polyimide powder having terminal acid anhydride groups. The weight average molecular weight (Mw) of Polyimide Resin 1 measured by GPC was 25,000. In addition, polyimide resin 1 1 H-NMR was measured, and the imidization rate was calculated from the quantitative value of the amide peak relative to the peak of the aromatic ring of the polyimide. The imidization rate was 99% or more.

[0130] (Synthesis of Tetraphenylphosphonium 4,4'-sulfonyldiphenolate) A separable flask equipped with a stirrer was charged with 37.5 g (0.15 mol) of 4,4'-bisphenol S and 100 mL of methanol, and the mixture was stirred and dissolved at room temperature. A solution of 4.0 g (0.1 mol) of sodium hydroxide dissolved in 50 mL of methanol was then added with further stirring. A solution of 41.9 g (0.1 mol) of tetraphenylphosphonium bromide dissolved in 150 mL of methanol was then added. Stirring was continued for a while, and after adding 300 mL of methanol, the solution in the flask was added dropwise to a large amount of water with stirring, yielding a white precipitate. The precipitate was filtered and dried. This yielded white crystalline tetraphenylphosphonium 4,4'-sulfonyldiphenolate.

[0131] (Preparation of Composition G) 100 parts by mass of the above polyimide resin 1, 60 parts by mass of Biscoat #802 (manufactured by Osaka Organic Chemical Industry Co., Ltd., a mixture of polyfunctional acrylates, a compound having 5 to 10 acryloyl groups), 20 parts by mass of NK Ester A-9550 (manufactured by Shin-Nakamura Chemical Co., Ltd., a mixture of polyfunctional acrylates, a compound having 5 to 6 acryloyl groups), 20 parts by mass of Biscoat #300 (manufactured by Osaka Organic Chemical Industry Co., Ltd., a mixture of polyfunctional acrylates, a compound having 3 to 4 acryloyl groups), 10 parts by mass of Irugacure OXE01 (manufactured by BASF, an oxime ester type photo radical generator), 10 parts by mass of Percadox BC (manufactured by Kayaku Nurion Co., Ltd., an organic peroxide, cumyl peroxide), 7 parts by mass of TECHMORE VG3101L (manufactured by Printec Co., Ltd., an epoxy compound), 3 parts by mass of Celloxide 2021P (manufactured by Daicel Corporation, an epoxy compound), 3 parts by mass of the tetraphenylphosphonium·4,4'-sulfonyldiphenolate synthesized above, 5 parts by mass of KBM-503 (manufactured by Shin-Etsu Chemical Co., Ltd., 3-methacryloxypropyltrimethoxysilane), 2 parts by mass of X-12-967C (manufactured by Shin-Etsu Chemical Co., Ltd., 3-trimethoxysilylpropylsuccinic anhydride), 0.1 part by mass of FC4432 (manufactured by 3M, a fluorine-based surfactant), and 2 parts by mass of distilled water were dissolved in 282 parts by mass of ethyl acetate and 282 parts by mass of γ-butyrolactone, and stirred at room temperature until the raw materials were completely dissolved to obtain a solution. Then, the solution was filtered through a nylon filter with a pore size of 0.2 μm to obtain a varnish-like composition G.

[0132] <Production of Composition H> 26.0 parts by mass of an epoxy resin (manufactured by Nippon Kayaku Co., Ltd., product name: EPPN 201, polyfunctional epoxy resin, phenol novolak type epoxy resin), 7.8 parts by mass of a phenoxy resin (manufactured by Mitsubishi Chemical Corporation, product name: jER 1256, bisphenol A type phenoxy resin), 0.8 parts by mass of a photoacid generator (manufactured by San-Apro Ltd., product name: CPI-310B, onium salt compound), 0.1 parts by mass of a surfactant (manufactured by DIC Corporation, product name: R-41, fluorine-containing group and lipophilic group-containing oligomer), and 0.3 parts by mass of a silane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd., product name: X-12-967C) were dissolved in 65.0 parts by mass of propylene glycol monomethyl ether acetate and mixed at room temperature for 2.5 hours to obtain a mixed solution. Subsequently, pure water was added to the mixed solution so that the water content in 100% by mass of the composition was 7300 ppm, and the mixture was mixed again. The mixed solution was filtered through a 0.2 μm polypropylene filter to obtain a varnish-like composition H.

[0133] [Examples 7 to 12] [Manufacture of Optical Waveguide] [Formation of Underclad] Liquid films obtained by spin-coating the clad compositions shown in Table 2 on an 8-inch silicon wafer were heated at 120 °C for 4 minutes to dry, and underclad layers with a thickness of 10 μm were formed respectively. Subsequently, the silicon wafers on which the underclad layers were formed were heated in a nitrogen atmosphere at 230 °C for 120 minutes to form underclads respectively.

[0134] [Formation of Core] Liquid films obtained by spin-coating composition G on the underclad were heated at 110 °C for 3 minutes to dry, and core layers with a thickness of 7 μm were formed respectively. Subsequently, with respect to the obtained core layers, using an automatic exposure machine, i-line with a wavelength of 365 nm was irradiated at 1300 mJ / cm 2Exposed with the exposure amount of , developed with cyclopentanone and PGMEA using a spray developer, then heated on a hot plate in the atmosphere at 120 °C for 2 minutes, and the silicon wafer was heated in a nitrogen atmosphere at 170 °C for 120 minutes to form cores with a line width of 10 μm respectively.

[0135] (Formation of overclad) A liquid film obtained by spin-coating the composition of the clad described in Table 2 on the core was heated at 120 °C for 4 minutes and dried to form an overclad layer with a thickness of 17 μm from the underclad surface (a thickness of 10 μm from the core surface) respectively. Subsequently, the silicon wafer on which the overclad layer was formed was heated in a nitrogen atmosphere at 230 °C for 120 minutes to form an overclad, and the optical waveguides of Examples 7 to 12 were obtained respectively.

[0136] [Comparative Example 1] (Manufacture of optical waveguide) (Formation of underclad) A liquid film obtained by spin-coating Composition G on an 8-inch silicon wafer was heated at 110 °C for 3 minutes and dried to form an underclad layer with a thickness of 10 μm. Subsequently, for the obtained underclad layer, using an automatic exposure machine, the entire surface was exposed with i-line of wavelength 365 nm at an exposure amount of 1300 mJ / cm 2 , heated on a hot plate in the atmosphere at 120 °C for 2 minutes, and the silicon wafer was heated in a nitrogen atmosphere at 170 °C for 120 minutes to form an underclad.

[0137] (Formation of core) A liquid film obtained by spin-coating Composition H on the underclad was heated at 100 °C for 3 minutes and dried to form a core layer with a thickness of 7 μm. Subsequently, for the obtained core layer, using an automatic exposure machine, the i-line of wavelength 365 nm was exposed at 600 mJ / cm 2Exposed with the exposure amount, developed with cyclopentanone and PGMEA using a spray developer, then heated on a hot plate in the atmosphere at 70 °C for 5 minutes, and the silicon wafer was heated in a nitrogen atmosphere at 170 °C for 180 minutes to form a core with a line width of 10 μm.

[0138] (Formation of Overclad) The liquid film obtained by spin-coating Composition G on the core was heated at 110 °C for 3 minutes to dry, and an overclad layer with a thickness of 17 μm from the underclad surface (10 μm from the core surface) was formed. Subsequently, for the obtained overclad layer, using an automatic exposure machine, i-line with a wavelength of 365 nm was exposed over the entire surface with an exposure amount of 1300 mJ / cm 2 , heated on a hot plate in the atmosphere at 120 °C for 2 minutes, and the silicon wafer was heated in a nitrogen atmosphere at 170 °C for 120 minutes to form an overclad, and the optical waveguide of Comparative Example 1 was obtained.

[0139] [Measurement and Evaluation] [Refractive Index Measurement of Composition] For the clad compositions of Examples 1 to 6, the refractive index was measured using a prism coupler (manufactured by Metricon) based on the following conditions. From the refractive index values at three wavelengths of the following measurement wavelengths, the refractive index at 30 °C and a wavelength of 1310 nm was calculated using the Cauchy dispersion formula. The refractive indices at 30 °C and a wavelength of 1310 nm for each example are shown in Table 1 respectively. Substrate: Si wafer Film thickness: 5 μm Measurement temperature: 30 °C Measurement wavelengths: 404 nm, 633 nm, 832 nm

[0140] [Absorbance Measurement of Composition] For the clad compositions of Examples 1 to 6, based on the following conditions, the absorbance at 22 °C and a wavelength of 1310 nm was measured. The absorbance of the composition was the value obtained by dividing the measured value by the concentration of the measurement sample. Measuring device: Spectrophotometer (manufactured by JASCO Corporation, product name: V-670 EX) Test method: Parallel light transmittance measurement Measurement temperature: 22℃ Measurement wavelength: 1310nm Measurement sample: Deuterated chloroform solution of the composition Concentration of measurement sample: 20%

[0141] <Evaluation of propagation loss in optical waveguides> (Environmental Testing) The optical waveguides fabricated on silicon wafers of Examples 7 to 12 and Comparative Example 1 were subjected to an environmental test by heating them in an oven at 125° C. for 1000 hours, and optical waveguides after the environmental test were obtained.

[0142] (Propagation loss evaluation) The propagation loss of the optical waveguide before and after the environmental test was measured using the cutback method. Specifically, laser light with a wavelength of 1310 nm was incident on the core of the test piece via a single-mode optical fiber. Next, the intensity of the light emitted from the core of the test piece was obtained while changing the length of the test piece, and the propagation loss per unit length of the optical waveguide was calculated. The propagation loss of the optical waveguide was evaluated based on the following evaluation criteria. The evaluation results for each example and comparative example are shown in Table 2. A: The difference between the propagation loss of the optical waveguide after the environmental test and the propagation loss of the optical waveguide before the environmental test is less than 0.15 dB / cm B: The difference between the propagation loss of the optical waveguide after the environmental test and the propagation loss of the optical waveguide before the environmental test is 0.15 dB / cm or more and less than 0.40 dB / cm C: The difference between the propagation loss of the optical waveguide after the environmental test and the propagation loss of the optical waveguide before the environmental test is 0.40 dB / cm or more

[0143] [Table 1]

[0144] [Table 2]

[0145] According to Table 2, all of the optical waveguides in the examples had good evaluation results for propagation loss evaluation. That is, it can be understood that according to the clad composition of the present embodiment, it is possible to obtain an optical waveguide with improved thermal reliability.

Explanation of symbols

[0146] 10 Underclad 20 Core 30 Overclad 50 Wafer 100 Optical waveguide

Claims

1. A composition for a cladding that can be used for the cladding of an optical waveguide, comprising a cyclic olefin resin (A) and a phenol compound (B).

2. The composition for a cladding according to claim 1, wherein the cyclic olefin resin (A) is an alkali-soluble resin.

3. The composition for a cladding according to claim 1 or 2, wherein the cyclic olefin resin (A) contains a norbornene resin.

4. The composition for a cladding according to claim 1 or 2, wherein the cyclic olefin resin (A) has an acidic group.

5. The composition for a cladding according to claim 1 or 2, wherein the cyclic olefin resin (A) contains a structural unit represented by the following formula (1). 【Chemical Formula 1】 (In the above formula (1), z is an integer of 1 or more and 10 or less)

6. The composition for a cladding according to claim 5, wherein the content of the structural unit represented by the formula (1) in the cyclic olefin resin (A) is 20 mol% or more and 70 mol% or less when the total of all structural units in the cyclic olefin resin (A) is 100 mol%.

7. The composition for a cladding according to claim 1 or 2, wherein the cyclic olefin resin (A) contains a structural unit represented by the following formula (2). 【Chemical 2】 (In the above formula (2), x is an integer of 0 or more and 10 or less)

8. The composition for a cladding according to claim 1 or 2, wherein the cyclic olefin resin (A) contains a structural unit represented by the following formula (3). 【Chemical Formula 3】 (In the above formula (3), y is an integer of 0 or more and 10 or less)

9. The composition for a cladding according to claim 1 or 2, wherein the content of the cyclic olefin resin (A) in the composition for a cladding is 20% by mass or more when the total solid content in the composition for a cladding is 100% by mass.

10. The composition for a cladding according to claim 1 or 2, wherein the melting point of the phenol compound (B) is 50°C or more and 150°C or less.

11. The composition for a cladding according to claim 1 or 2, wherein the phenol compound (B) contains a phenol compound (B1) having a substituent containing an aliphatic hydrocarbon group.

12. The composition for a cladding according to claim 11, wherein the hydroxyl equivalent of the phenol compound (B1) having a substituent containing an aliphatic hydrocarbon group is 150 g / eq or more and 250 g / eq or less.

13. The content of the phenolic compound (B) in the clad composition is 0.5 parts by mass or more and 30 parts by mass or less when the content of the cyclic olefin resin (A) in the clad composition is 100 parts by mass. The clad composition according to claim 1 or 2.

14. The clad composition according to claim 1 or 2, further comprising an epoxy compound (C).

15. The clad composition according to claim 1 or 2, further comprising a photoacid generator (D).

16. The clad composition according to claim 1 or 2, further comprising an organic solvent (E).

17. The clad composition according to claim 1 or 2, which is in the form of a varnish.

18. The clad composition according to claim 1 or 2, having a refractive index of 1.470 or more and 1.530 or less at 30 °C and a wavelength of 1310 nm.

19. The clad composition according to claim 1 or 2, having an absorbance of 0.040 or more and 0.080 or less at 22 °C and a wavelength of 1310 nm.

20. A composition set comprising the clad composition according to claim 1 or 2 and a core composition capable of being used for the core of an optical waveguide.

21. The composition set according to claim 20, wherein the core composition comprises a polyimide resin and a polyfunctional (meth)acrylate.

22. An optical waveguide comprising a clad made of the clad composition according to claim 1 or 2.

23. Comprising a silicon photonics device, The electronic device, wherein the silicon photonics device comprises the optical waveguide according to claim 22.

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