Resin compositions, dry films, optical waveguides, optoelectronic composite substrates, and electronic components

Abstract

The present invention provides a resin composition capable of reducing the warping of the resulting dry film. [Solution] A resin composition that can be used in an optical waveguide, comprising a resin (A) having a norbornene skeleton and a compound (B) having a cyclic ether structure, wherein the content of the compound (B) having a cyclic ether structure in the resin composition is 34 parts by mass or more and 100 parts by mass or less, when the content of the resin (A) having a norbornene skeleton in the resin composition is 100 parts by mass.

Description

[Technical Field]

[0001] This invention relates to resin compositions, dry films, optical waveguides, optoelectronic composite substrates, and electronic components. [Background technology]

[0002] In recent years, there has been a growing demand for components in information and communication equipment that can achieve more advanced information communication, such as increased data capacity and higher communication speeds. Optical waveguides are being considered as one such component.

[0003] Patent Document 1 describes a polymer optical waveguide forming material comprising a polymer containing a norbornene-based structural unit represented by a predetermined formula (1), a photoacid generator that generates acid by irradiation with a chemical beam, and a monomer component that polymerizes with the acid generated by the photoacid generator, wherein the monomer component contains an epoxy compound having an epoxy group. Patent Document 1 describes a polymer optical waveguide forming material that has good processability and can reduce transmission loss. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] International Publication No. 2008 / 126499 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] The present invention provides a resin composition capable of reducing the warping of the resulting dry film. [Means for solving the problem]

[0006] According to the present invention, the following resin compositions, dry films, optical waveguides, optoelectronic composite substrates, and electronic components are provided.

[0007] [1] A resin composition that can be used in optical waveguides, The material comprises a resin (A) having a norbornene skeleton and a compound (B) having a cyclic ether structure. The resin composition wherein the content of the compound (B) having the cyclic ether structure in the resin composition is 34 parts by mass or more and 100 parts by mass or less, when the content of the resin (A) having the norbornene skeleton in the resin composition is 100 parts by mass. [2] The resin composition according to [1], wherein the compound (B) having the cyclic ether structure comprises at least one selected from the group consisting of oxetane compounds (B1) and epoxy compounds (B2). [3] The compound (B) having the cyclic ether structure comprises an oxetane compound (B1) and an epoxy compound (B2). The resin composition according to [1] or [2], wherein the mass ratio (B1 / B2) of the content of the oxetane compound (B1) in the resin composition to the content of the epoxy compound (B2) in the resin composition is 3.0 or more. [4] The compound (B) having the cyclic ether structure includes an oxetane compound (B1), The resin composition according to any one of [1] to [3], wherein the oxetane compound (B1) comprises a polyfunctional oxetane compound. [5] The resin composition according to any one of [1] to [4], wherein the compound (B) having the cyclic ether structure is a compound that is liquid at 23°C. [6] The resin composition according to any one of [1] to [5], wherein the content of the bifunctional oxetane compound having an aromatic ring in the compound (B) having a cyclic ether structure is less than 5 parts by mass when the content of the compound (B) having a cyclic ether structure in the resin composition is 100 parts by mass. [7] In the compound (B) having the cyclic ether structure, the content of the bifunctional epoxy compound having an aromatic ring is less than 5 parts by mass when the content of the compound (B) having the cyclic ether structure in the resin composition is 100 parts by mass. The resin composition according to any one of [1] to [6]. [8] The resin (A) having the norbornene skeleton contains a resin having an aromatic ring. The resin composition according to any one of [1] to [7]. [9] The total content of the resin (A) having the norbornene skeleton and the compound (B) having the cyclic ether structure in the resin composition is 50% by mass or more when the total of the nonvolatile components in the resin composition is 100% by mass. The resin composition according to any one of [1] to [8].

[10] The resin composition according to any one of [1] to [9], further comprising a photosensitizer (C).

[11] The resin composition according to any one of [1] to

[10] , having a refractive index of 1.51 or more and 1.60 or less.

[12] The resin composition according to any one of [1] to

[11] , which is a resin composition capable of being used for a core layer of an optical waveguide.

[13] A dry film comprising a resin layer composed of the resin composition according to any one of [1] to

[12] .

[14] The dry film according to

[13] , wherein the light transmittance of the resin layer at a wavelength of 850 nm is 85% or more.

[15] An optical waveguide comprising a core layer and a cladding layer, where at least one of the core layer and the cladding layer is a layer containing the resin composition according to any one of [1] to

[12] .

[16] A substrate, An optoelectronic composite substrate comprising the optical waveguide according to

[15] provided on the substrate.

[17] ​An electronic component comprising the optoelectronic composite substrate described in

[16] above. [Effects of the Invention]

[0008] According to the present invention, a resin composition capable of reducing the warping of the resulting dry film can be provided. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic cross-sectional view showing an example of the structure of the optoelectronic composite substrate of this embodiment. [Modes for carrying out the invention]

[0010] Embodiments of the present invention will be described below with reference to the drawings. Note that the drawings are simplified diagrams and do not correspond to the actual dimensional ratios. Unless otherwise specified, the numerical range "A~B" represents A or greater and B or less.

[0011] One method for manufacturing optical waveguides is to sequentially laminate dry films to form each layer constituting the optical waveguide. Such dry films require reduced warping, for example, to improve handling. The present invention provides a resin composition that can reduce the warping of the resulting dry film.

[0012] [Resin composition] The resin composition of this embodiment is a resin composition that can be used in optical waveguides and comprises a resin (A) having a norbornene skeleton and a compound (B) having a cyclic ether structure, wherein the content of the compound (B) having a cyclic ether structure in the resin composition is 34 parts by mass or more and 100 parts by mass or less, when the content of the resin (A) having a norbornene skeleton in the resin composition is 100 parts by mass.

[0013] The refractive index of the resin composition of this embodiment is preferably 1.51 or higher, more preferably 1.52 or higher, and even more preferably 1.53 or higher, from the viewpoint of further improving the optical propagation efficiency of the optical waveguide, and the upper limit is not particularly limited, but may be, for example, 1.60 or lower, or 1.59 or lower. Furthermore, the refractive index of the resin composition of this embodiment is preferably 1.51 or higher and 1.60 or lower, more preferably 1.52 or higher and 1.60 or lower, and even more preferably 1.53 or higher and 1.59 or lower, from the viewpoint of further improving the optical propagation efficiency of the optical waveguide. The refractive index of a resin composition refers to the refractive index measured for a resin film made of the resin composition using an Abbe refractometer under conditions of 23°C and 589 nm. A resin film made of a resin composition can be produced, for example, by coating and drying the resin composition on a substrate film, as described in the examples.

[0014] The light transmittance of the resin composition of this embodiment for a wavelength of 850 nm is preferably 85% to 100%, more preferably 90% to 100%, more preferably 95% to 100%, more preferably 97% to 100%, and more preferably 98% to 100%, from the viewpoint of further improving the light propagation efficiency of the optical waveguide. The light transmittance of a resin composition at a wavelength of 850 nm refers to the value of the light transmittance measured by an ultraviolet-visible spectrophotometer for a resin film made of a resin composition with a thickness of 40 μm. A resin film consisting of a resin composition with a thickness of 40 μm can be produced, for example, by coating and drying the resin composition on a substrate film, as described in the examples.

[0015] The shape of the resin composition in this embodiment is not particularly limited and may include, for example, a film, a membrane, a varnish, a sheet, or the like.

[0016] The following describes each component of the resin composition of this embodiment.

[0017] <Resin having a norbornene skeleton (A)> The resin composition of this embodiment includes a resin (A) having a norbornene skeleton. The resin (A) having a norbornene skeleton is not particularly limited as long as it is a resin having a norbornene skeleton, and may be a homopolymer of a norbornene compound, a copolymer of a norbornene compound, or a copolymer of a norbornene compound and other compounds.

[0018] The resin (A) having a norbornene skeleton preferably includes a resin having an aromatic ring, from the viewpoint of adjusting the refractive index to a more appropriate range. The resin having an aromatic ring is preferably a resin containing a phenyl group.

[0019] The norbornene skeleton resin (A) preferably includes a resin containing at least one structural unit selected from the group consisting of the structural unit represented by formula (1), the structural unit represented by formula (2), and the structural unit represented by formula (3).

[0020] The norbornene skeleton resin (A) more preferably includes at least one selected from the group consisting of a resin containing the structural unit represented by formula (1) and the structural unit represented by formula (2), and a resin containing the structural unit represented by formula (1) and the structural unit represented by formula (3).

[0021] [ka]

[0022] In equation (1), a represents an integer between 0 and 15, inclusive. In formula (1), a is preferably an integer between 1 and 12, more preferably an integer between 2 and 10, and even more preferably an integer between 3 and 7.

[0023] [ka]

[0024] In formula (2), b represents an integer of 0 or more and 6 or less, and R 21 represents an aryl group.

[0025] In formula (2), b preferably represents an integer of 1 or more and 5 or less, more preferably represents an integer of 1 or more and 4 or less, and even more preferably represents an integer of 1 or more and 3 or less. In formula (2), R 21 is a group selected from the group consisting of, for example, a phenyl group, a tolyl group, a naphthyl group, an anthracenyl group, etc., and is preferably a phenyl group.

[0026] In formula (2), b represents an integer of 1 or more and 3 or less, R 21 preferably represents a phenyl group, b is 2, and R 21 more preferably represents a phenyl group.

[0027]

Chemical formula

[0028] In formula (3), c represents an integer of 1 or more and 6 or less, and R 31 , R 32 and R 33 each independently represent any one selected from the group consisting of an aryl group and an alkyl group having 1 to 6 carbon atoms, and at least one selected from the group consisting of R 31 , R 32 and R 33 is an aryl group.

[0029] In formula (3), c preferably represents an integer of 1 or more and 4 or less, more preferably represents 1 or 2, and even more preferably represents 1.

[0030] In formula (3), R 31 , R 32 and R 33 in, the aryl group is a group selected from the group consisting of, for example, a phenyl group, a tolyl group, a naphthyl group, an anthracenyl group, etc., and is preferably a phenyl group. In formula (3), R31 , R 32 and R 33 In this, the alkyl group having 1 to 6 carbon atoms is preferably an alkyl group having 1 to 4 carbon atoms, more preferably an alkyl group having 1 to 3 carbon atoms, and even more preferably a methyl group or an ethyl group. The alkyl group having 1 to 6 carbon atoms may be a linear alkyl group or a branched alkyl group.

[0031] In equation (3), c represents 1 or 2, and R 31 and R 32 Each of these independently represents an aryl group, R 33 It is preferable that represents an alkyl group having 1 to 6 carbon atoms, c represents 1 or 2, and R 31 and R 32 R indicates a phenyl group, 33 It is more preferable that represents an alkyl group having 1 to 3 carbon atoms, where c represents 1, and R represents 1. 31 and R 32 R indicates a phenyl group, 33 It is even more preferable that it exhibits a methyl group.

[0032] The refractive index of the resin (A) having a norbornene skeleton is preferably 1.54 or higher, more preferably 1.55 or higher, from the viewpoint of further improving the optical propagation efficiency of the optical waveguide, and the upper limit is not particularly limited, but may be, for example, 1.60 or lower, or 1.59 or lower. Furthermore, the refractive index of the resin (A) having a norbornene skeleton is preferably 1.54 or higher and 1.60 or lower, more preferably 1.55 or higher and 1.59 or lower, from the viewpoint of further improving the optical propagation efficiency of the optical waveguide. The refractive index of resin (A) having a norbornene skeleton refers to the refractive index measured with an Abbe refractometer under conditions of 23°C and 589 nm.

[0033] The weight-average molecular weight (Mw) of the resin (A) having a norbornene skeleton is preferably 10,000 to 300,000, more preferably 30,000 to 200,000, and even more preferably 50,000 to 120,000. The weight-average molecular weight (Mw) of resin (A) having a norbornene skeleton can be determined by gel permeation chromatography (GPC) using polystyrene as a standard substance.

[0034] The content of the norbornene skeleton resin (A) in the resin composition of this embodiment is preferably 30% to 75% by mass, more preferably 40% to 75% by mass, and even more preferably 50% to 75% by mass, when the total amount of nonvolatile components in the resin composition is 100% by mass.

[0035] A resin (A) having a norbornene skeleton can be produced, for example, by known methods, and more specifically, by polymerizing monomers capable of forming each structural unit in any way.

[0036] The resin (A) having a norbornene skeleton may be a resin having one type of norbornene skeleton, or it may contain two or more types of resins having two or more types of norbornene skeletons.

[0037] <Compound having a cyclic ether structure (B)> The resin composition of this embodiment contains compound (B) having a cyclic ether structure. In this specification, compound (B) having a cyclic ether structure means a low molecular weight compound, for example, a compound with a molecular weight of 1000 or less.

[0038] The compound (B) having a cyclic ether structure preferably includes at least one selected from the group consisting of oxetane compounds (B1) and epoxy compounds (B2).

[0039] Compound (B) having a cyclic ether structure preferably includes a compound that is liquid at 23°C, from the viewpoint of further reducing the warping of the dry film.

[0040] (Oxetane compound (B1)) The compound (B) having a cyclic ether structure preferably includes an oxetane compound (B1). From the viewpoint of further improving the heat resistance of the resin composition, the oxetane compound (B1) preferably includes a polyfunctional oxetane compound.

[0041] Here, a polyfunctional oxetane compound refers to a compound containing two or more oxetanyl groups, while a monofunctional oxetane compound refers to a compound containing one oxetanyl group.

[0042] The polyfunctional oxetane compound preferably comprises at least one selected from the group consisting of difunctional oxetane compounds and trifunctional oxetane compounds, and more preferably comprises a difunctional oxetane compound. The difunctional oxetane compound preferably includes an aliphatic difunctional oxetane compound.

[0043] The oxetane compound (B1) more preferably includes polyfunctional oxetane compounds and monofunctional oxetane compounds. The monofunctional oxetane compounds preferably include aliphatic monofunctional oxetane compounds.

[0044] The refractive index of the oxetane compound (B1) is preferably 1.41 or higher, more preferably 1.42 or higher, and even more preferably 1.43 or higher, from the viewpoint of further improving the optical propagation efficiency of the optical waveguide. The upper limit is not particularly limited, but may be, for example, 1.50 or lower, 1.49 or lower, or 1.47 or lower. Furthermore, the refractive index of the oxetane compound (B1) is preferably 1.41 or higher and 1.50 or lower, more preferably 1.42 or higher and 1.49 or lower, and even more preferably 1.43 or higher and 1.47 or lower, from the viewpoint of further improving the optical propagation efficiency of the optical waveguide. The refractive index of the oxetane compound (B1) refers to the refractive index measured at 23°C and 589 nm using an Abbe refractometer.

[0045] (Epoxy compound (B2)) The compound (B) having a cyclic ether structure preferably includes an epoxy compound (B2) from the viewpoint of further improving the curing speed of the resin composition and further improving the crosslinking density of the cured product made from the resin composition. In this specification, a polyfunctional epoxy compound means a compound containing two or more epoxy groups.

[0046] The epoxy compound (B2) preferably includes an aliphatic epoxy compound.

[0047] The epoxy compound (B2) preferably includes a compound having an alicyclic structure within its molecule. Here, the statement that the epoxy compound (B2) has an alicyclic structure within its molecule means that it includes an alicyclic structure in addition to the epoxy ring structure. However, the alicyclic structure in this embodiment includes a fused ring structure in which an epoxy ring and an aliphatic ring are fused, and a spiro-ring structure in which an epoxy ring and an aliphatic ring are bonded by a spiro-bonding atom. The number of members in the alicyclic structure is not particularly limited, but is preferably 4-membered to 10-membered rings, more preferably 4-membered to 8-membered rings, even more preferably 5-membered or 6-membered rings, and even more preferably 6-membered rings.

[0048] The epoxy compound (B2) preferably includes a polyfunctional epoxy compound, from the viewpoint of further improving the curing speed of the resin composition and further improving the crosslinking density of the cured product made from the resin composition. The polyfunctional epoxy compound preferably comprises at least one selected from the group consisting of difunctional epoxy compounds and trifunctional epoxy compounds, and more preferably comprises a difunctional epoxy compound.

[0049] The refractive index of the epoxy compound (B2) is preferably 1.45 or higher, more preferably 1.48 or higher, and even more preferably 1.50 or higher, from the viewpoint of further improving the optical propagation efficiency of the optical waveguide. The upper limit is not particularly limited, but may be, for example, 1.55 or lower, 1.54 or lower, or 1.52 or lower. Furthermore, the refractive index of the epoxy compound (B2) is preferably 1.45 or higher and 1.55 or lower, more preferably 1.48 or higher and 1.54 or lower, and even more preferably 1.50 or higher and 1.52 or lower, from the viewpoint of further improving the optical propagation efficiency of the optical waveguide. The refractive index of epoxy compound (B2) refers to the refractive index measured at 23°C and 589 nm using an Abbe refractometer.

[0050] The content of compound (B) having a cyclic ether structure in the resin composition of this embodiment is 34 parts by mass or more and 100 parts by mass or less, when the content of resin (A) having a norbornene skeleton in the resin composition is 100 parts by mass. The content of compound (B) having a cyclic ether structure in the resin composition of this embodiment is preferably 35 to 80 parts by mass, more preferably 35 to 60 parts by mass, even more preferably 36 to 50 parts by mass, even more preferably 36 to 45 parts by mass, and even more preferably 36 to 42 parts by mass, from the viewpoint of further reducing the warping of the dry film and adjusting other physical properties such as the refractive index of the resin composition to an appropriate range, when the content of resin (A) having a norbornene skeleton in the resin composition is 100 parts by mass.

[0051] The content of the oxetane compound (B1) in the resin composition of this embodiment is preferably 20 parts by mass or more and 70 parts by mass or less, more preferably 25 parts by mass or more and 60 parts by mass or less, even more preferably 28 parts by mass or more and 50 parts by mass or less, and even more preferably 30 parts by mass or more and 40 parts by mass or less, when the content of the resin (A) having a norbornene skeleton in the resin composition is 100 parts by mass.

[0052] The content of the epoxy compound (B2) in the resin composition of this embodiment is preferably 5 parts by mass or more and 20 parts by mass or less, more preferably 6 parts by mass or more and 15 parts by mass or less, and even more preferably 7 parts by mass or more and 12 parts by mass or less, when the content of the resin (A) having a norbornene skeleton in the resin composition is 100 parts by mass.

[0053] The compound (B) having a cyclic ether structure preferably includes an oxetane compound (B1) and an epoxy compound (B2). The mass ratio (B1 / B2) of the content of oxetane compound (B1) in the resin composition to the content of epoxy compound (B2) in the resin composition of this embodiment is preferably 3.0 to 10.0, more preferably 3.2 to 8.0, even more preferably 3.5 to 7.0, and even more preferably 3.8 to 6.5.

[0054] The content of the difunctional oxetane compound having an aromatic ring in compound (B) having a cyclic ether structure is preferably less than 5 parts by mass, more preferably less than 3 parts by mass, even more preferably less than 1 part by mass, even more preferably less than 0.5 parts by mass, and even more preferably less than 0.1 parts by mass, when the content of compound (B) having a cyclic ether structure in the resin composition of this embodiment is 100 parts by mass, and even more preferably, compound (B) having a cyclic ether structure does not contain the difunctional oxetane compound having an aromatic ring.

[0055] The content of the bifunctional epoxy compound having an aromatic ring in compound (B) having a cyclic ether structure is preferably less than 5 parts by mass, more preferably less than 3 parts by mass, even more preferably less than 1 part by mass, even more preferably less than 0.5 parts by mass, and even more preferably less than 0.1 parts by mass, when the content of compound (B) having a cyclic ether structure in the resin composition is 100 parts by mass, and even more preferably, compound (B) having a cyclic ether structure does not contain the bifunctional epoxy compound having an aromatic ring.

[0056] Compound (B) having a cyclic ether structure may be a compound having one cyclic ether structure, or it may contain two or more compounds having cyclic ether structures.

[0057] <Photosensitive agent (C)> The resin composition of this embodiment preferably further comprises a photosensitive agent (C). The photosensitive agent (C) is not particularly limited, as long as it is capable of generating active species in response to light to cure the photosensitive resin composition.

[0058] The photosensitive agent (C) comprises, for example, at least one selected from the group consisting of photocationic polymerization initiators and photoradical polymerization initiators, and preferably comprises a photocationic polymerization initiator.

[0059] The photocationic polymerization initiator comprises, for example, at least one selected from the group consisting of sulfonium salt type polymerization initiators and iodonium salt type polymerization initiators, preferably a sulfonium salt type polymerization initiator, more preferably a triarylsulfonium salt type polymerization initiator, and even more preferably a triphenylsulfonium salt type polymerization initiator.

[0060] The content of the photosensitive agent (C) in the resin composition of this embodiment is preferably 0.05 parts by mass or more and 3 parts by mass or less, more preferably 0.1 parts by mass or more and 2 parts by mass or less, and even more preferably 0.3 parts by mass or more and 1 part by mass or less, when the content of the resin (A) having a norbornene skeleton in the resin composition is 100 parts by mass.

[0061] The photosensitive agent (C) may be one type of photosensitive agent or may contain two or more types of photosensitive agents.

[0062] <Antioxidant (D)> The resin composition of this embodiment preferably further comprises an antioxidant (D). The antioxidant (D) is not particularly limited and includes, for example, at least one selected from the group consisting of phenol-type antioxidants, phosphorus-type antioxidants, amine-type antioxidants, and thioether-type antioxidants, and preferably at least one selected from the group consisting of phenol-type antioxidants and phosphorus-type antioxidants. The antioxidant (D) in this embodiment may be one type of antioxidant, or it may contain two or more types of antioxidants.

[0063] The content of the antioxidant (D) in the resin composition of this embodiment is preferably 0.05 parts by mass or more and 10 parts by mass or less, more preferably 0.1 parts by mass or more and 5 parts by mass or less, and even more preferably 0.5 parts by mass or more and 3 parts by mass or less, when the content of the resin (A) having a norbornene skeleton in the resin composition is 100 parts by mass.

[0064] <Organic solvent (E)> The resin composition of this embodiment may contain an organic solvent (E). When the resin composition of this embodiment contains an organic solvent (E), it can be made into a varnish-like resin composition.

[0065] The organic solvent (E) of this embodiment includes, for example, at least one selected from the group consisting of acetone, methyl ethyl ketone, methyl amyl ketone, toluene, propylene glycol monomethyl ether, propylene glycol methyl ethyl ether, propylene glycol dimethyl ether, propylene glycol 1-monomethyl 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, and butyl lactate. The organic solvent (E) in this embodiment may be one type of organic solvent, or it may contain two or more types of organic solvents.

[0066] When the resin composition of this embodiment contains an organic solvent (E), the concentration of total solids (non-volatile components) in the resin composition is preferably 10% by mass or more and 60% by mass or less, more preferably 20% by mass or more and 55% by mass or less, and even more preferably 30% by mass or more and 50% by mass or less, from the viewpoint of appropriately controlling the viscosity of the resin composition and sufficiently dissolving each component in the resin composition.

[0067] <Other ingredients> The resin composition of this embodiment may further contain, for example, surfactants, curing aids, leveling agents, colorants, preservatives, plasticizers, fillers, inorganic particles, degradation inhibitors, wettability improvers, antistatic agents, etc. The content of other components is appropriate.

[0068] The total content of the resin (A) having a norbornene skeleton and the compound (B) having a cyclic ether structure in the resin composition of this embodiment is preferably 50% by mass or more and less than 100% by mass, more preferably 70% by mass or more and less than 100% by mass, even more preferably 80% by mass or more and less than 100% by mass, even more preferably 90% by mass or more and less than 100% by mass, and even more preferably 95% by mass or more and less than 100% by mass, when the total amount of nonvolatile components in the resin composition is 100% by mass, from the viewpoint of further reducing the warping of the dry film.

[0069] From the viewpoint of further reducing the warping of the dry film, the total content of the resin (A) having a norbornene skeleton and the compound (B) having a cyclic ether structure in the resin composition of this embodiment is preferably 20% by mass or more and less than 100% by mass, more preferably 35% by mass or more and less than 100% by mass, even more preferably 50% by mass or more and less than 100% by mass, even more preferably 70% by mass or more and less than 100% by mass, even more preferably 80% by mass or more and less than 100% by mass, even more preferably 90% by mass or more and less than 100% by mass, and even more preferably 95% by mass or more and less than 100% by mass, when the total content of all components in the resin composition is taken as 100% by mass.

[0070] [Method for producing resin composition] The resin composition of this embodiment can be obtained, for example, by mixing each component. A film-like resin composition can be obtained, for example, by applying a varnish-like resin composition onto a base film and drying it.

[0071] [Uses of resin compositions] The resin composition of this embodiment is a resin composition that can be used in optical waveguides. The resin composition of this embodiment may be a resin composition that can be used in the core layer of an optical waveguide, or a resin composition that can be used in the cladding layer of an optical waveguide, but it is preferably a resin composition that can be used in the core layer of an optical waveguide.

[0072] [Dry film] The dry film of this embodiment comprises a resin layer made of the resin composition of this embodiment.

[0073] The resin composition forming the resin layer in this embodiment may be an uncured product, a semi-cured product, or a cured product, but it is preferably a semi-cured product.

[0074] The thickness of the resin layer in this embodiment is preferably 1 μm to 100 μm, more preferably 5 μm to 80 μm, even more preferably 10 μm to 60 μm, and even more preferably 30 μm to 50 μm.

[0075] The light transmittance of the resin layer in this embodiment for a wavelength of 850 nm is preferably 85% to 100%, more preferably 90% to 100%, more preferably 95% to 100%, more preferably 97% to 100%, and more preferably 98% to 100%, from the viewpoint of further improving the light propagation efficiency of the optical waveguide. The light transmittance of the resin layer at a wavelength of 850 nm refers to the light transmittance value measured by an ultraviolet-visible spectrophotometer.

[0076] The dry film of this embodiment preferably further comprises a base film and has a resin layer on the base film. For example, a resin film can be used as the base film. The resin constituting the base film is not particularly limited and includes, for example, at least one selected from the group consisting of polyethylene terephthalate and polyimide, and preferably includes polyethylene terephthalate.

[0077] From the viewpoint of further improving the handling of the dry film, the thickness of the base film in this embodiment is preferably 10 μm to 100 μm, more preferably 15 μm to 80 μm, even more preferably 20 μm to 60 μm, and even more preferably 25 μm to 40 μm.

[0078] The base film of this embodiment may be subjected to surface treatments such as antistatic treatment and mold release treatment.

[0079] The dry film of this embodiment may further include a cover film. Preferably, the cover film is provided in direct contact with the resin layer. When the dry film of this embodiment includes a base film, the cover film is preferably provided on the side of the resin layer opposite to the base film. The cover film is not particularly limited, but for example, an OPP cover film can be used.

[0080] The dry film of this embodiment can be obtained, for example, by applying the varnish-like resin composition of this embodiment onto a base film and drying it. Methods of application include, for example, direct application using various coating devices such as pin coaters, die coaters, comma coaters, and curtain coaters, as well as printing methods such as screen printing.

[0081] [Optical waveguide] The optical waveguide of this embodiment comprises a core layer and a cladding layer, wherein at least one of the core layer and the cladding layer is a layer containing the resin composition of this embodiment. In this embodiment, the optical waveguide preferably has a core layer that contains the resin composition of this embodiment.

[0082] Figure 1 is a schematic cross-sectional view showing an example of the structure of the optoelectronic composite substrate of this embodiment. The optical waveguide of this embodiment will be explained using Figure 1. In Figure 1, the optical waveguide 100 comprises a first cladding layer 20, a core layer 30, and a second cladding layer 40 in this order. In this specification, when the optical waveguide 100 is provided on a substrate 110, the cladding layer located on the substrate 110 side is referred to as the first cladding layer 20. Furthermore, hereafter, when simply referred to as "cladding layer," the concept includes both the first cladding layer 20 and the second cladding layer 40.

[0083] The core layer 30 is preferably a layer containing the resin composition of this embodiment. The resin composition contained in the core layer 30 may be uncured, semi-cured, or cured, but is preferably cured.

[0084] The preferred numerical range for the thickness of the core layer 30 is the same as the preferred numerical range for the thickness of the resin layer of the dry film in this embodiment.

[0085] The core layer 30 may have a waveguide pattern formed on it. Examples of methods for forming the waveguide pattern include exposure, etching, and replication.

[0086] The cladding layer of this embodiment may be a layer containing the resin composition of this embodiment, or it may be a layer composed of a material other than the resin composition of this embodiment. Examples of layers made from materials other than the resin composition of this embodiment include layers containing a resin composition that does not satisfy the composition of the resin composition of this embodiment.

[0087] The resin composition contained in the cladding layer of this embodiment may be uncured, semi-cured, or cured, but is preferably cured.

[0088] The thickness of the first cladding layer 20 is preferably 1 μm to 150 μm, more preferably 5 μm to 100 μm, even more preferably 10 μm to 50 μm, and even more preferably 15 μm to 35 μm, from the viewpoint of further improving the optical propagation efficiency of the optical waveguide. The thickness of the second cladding layer 40 is preferably 1 μm to 150 μm, more preferably 3 μm to 100 μm, even more preferably 5 μm to 70 μm, even more preferably 8 μm to 50 μm, and even more preferably 8 μm to 20 μm, from the viewpoint of further suppressing thermal deformation of the optical waveguide.

[0089] The optical waveguide 100 may have mirrors formed on it. One method for forming the mirrors is to create an inclined surface by laser processing or the like.

[0090] In addition to the first cladding layer 20, the core layer 30, and the second cladding layer 40, the optical waveguide 100 may also include other layers, provided that they do not affect the good performance of the optical waveguide 100.

[0091] [Optoelectric composite substrate] The optoelectronic composite substrate of this embodiment will be described with reference to Figure 1. The optoelectronic composite substrate 200 comprises a substrate 110 and an optical waveguide 100 provided on the substrate 110.

[0092] The substrate 110 can be, for example, a printed circuit board or a flexible circuit board, and is preferably a flexible circuit board. The substrate 110 may have vias formed on it.

[0093] The optoelectronic composite substrate 200 may further include a polyimide substrate on the side of the second cladding layer 40 opposite to the core layer 30.

[0094] The photoelectric composite substrate 200 may include light-emitting elements, light-receiving elements, and the like.

[0095] The optoelectronic composite substrate 200 can be obtained, for example, by (i) forming a first cladding layer 20 on a substrate 110, (ii) forming a core layer 30 on the first cladding layer 20, and (iii) forming a second cladding layer 40 on the core layer 30. Methods for forming each layer include, for example, laminating each layer sequentially by rolling a dry film to form each layer using methods such as roll lamination, vacuum roll lamination, flat lamination, vacuum flat lamination, atmospheric pressure pressing, and vacuum pressing.

[0096] [Electronic components] The electronic component of this embodiment includes the photoelectric composite substrate of this embodiment. Examples of electronic components in this embodiment include those found in electronic devices such as mobile phones, game consoles, routers, WDM devices, personal computers, televisions, and home servers.

[0097] The embodiments of the present invention have been described above, but these are merely examples, and various other configurations can also be adopted. Furthermore, the present invention is not limited to the embodiments described above, and any modifications, improvements, etc., that can achieve the objectives of the present invention are included in the present invention. [Examples]

[0098] The embodiment will be described in detail below based on examples and comparative examples. However, this embodiment is not limited in any way to the descriptions of these examples.

[0099] [Raw materials] First, let me explain the raw materials.

[0100] <Synthesis of resins> (Synthesis of resin (A-1)) In a glove box filled with dry nitrogen, where both moisture and oxygen concentrations were controlled to 1 ppm or less, 7.1 g (40.0 mmol) of n-hexylnorbornene and 12.8 g (40.0 mmol) of diphenylmethylnorbornenemethoxysilane were weighed into a 500 mL vial. 60 g of dehydrated toluene and 11 g of ethyl acetate were added, and the vial was sealed tightly with a silicone sealer. Next, 1.56 g (3.2 mmol) of Ni catalyst and 10 mL of anhydrous toluene were weighed into a 100 mL vial, a stirrer tip was added, and the vial was sealed tightly. The Ni catalyst was thoroughly stirred to completely dissolve it, obtaining the Ni catalyst solution. 1 mL of the Ni catalyst solution was accurately weighed using a syringe and quantitatively injected into the vial containing the two types of norbornene dissolved above. The vial was stirred at room temperature for 1 hour, and a significant increase in viscosity was observed. At this point, the stopper was removed, 60 g of tetrahydrofuran (THF) was added, and the mixture was stirred to obtain the reaction solution. A peracetic acid aqueous solution was prepared by adding 9.5 g of acetic anhydride, 18 g of hydrogen peroxide solution (30% concentration), and 30 g of deionized water to a 100 mL beaker and stirring. Next, the entire peracetic acid aqueous solution was added to the above reaction solution and stirred for 12 hours to perform the reduction treatment of Ni. Next, the completed reaction solution was transferred to a separatory funnel, the aqueous layer at the bottom was removed, and then 100 mL of a 30% aqueous solution of isopropyl alcohol was added and the mixture was vigorously stirred. After standing, complete two-layer separation occurred, and the aqueous layer was removed. This washing process was repeated a total of three times. Then, the oil layer was dropped into a large excess of acetone to reprecipitate the resulting polymer, which was separated from the filtrate by filtration. Finally, the polymer was heated and dried in a vacuum dryer set to 60°C for 12 hours to obtain a resin (A-1) having a norbornene skeleton. The weight-average molecular weight (Mw) of resin (A-1) having a norbornene skeleton, as measured by GPC, was 100,000, and the refractive index of resin (A-1) having a norbornene skeleton, as measured by an Abbe refractometer at 23°C and 589 nm, was 1.57.

[0101] (Synthesis of resin (A-2)) In a glove box filled with dry nitrogen, where both moisture and oxygen concentrations were controlled to 1 ppm or less, 7.1 g (40.0 mmol) of n-hexylnorbornene and 7.9 g (40.0 mmol) of 5-(2-phenylethyl)-bicyclo(2,2,1)hepta-2-ene were weighed into a 500 mL vial. 60 g of dehydrated toluene and 11 g of ethyl acetate were added, and the vial was sealed tightly with a silicone sealer. Next, 1.56 g (3.2 mmol) of Ni catalyst and 10 mL of anhydrous toluene were weighed into a 100 mL vial, a stirrer tip was added, and the vial was sealed tightly. The Ni catalyst was thoroughly stirred to completely dissolve it, obtaining the Ni catalyst solution. 1 mL of the Ni catalyst solution was accurately weighed using a syringe and quantitatively injected into the vial containing the two types of norbornene dissolved above. The vial was stirred at room temperature for 1 hour, and a significant increase in viscosity was observed. At this point, the stopper was removed, 60 g of tetrahydrofuran (THF) was added, and the mixture was stirred to obtain the reaction solution. A peracetic acid aqueous solution was prepared by adding 9.5 g of acetic anhydride, 18 g of hydrogen peroxide solution (30% concentration), and 30 g of deionized water to a 100 mL beaker and stirring. Next, the entire peracetic acid aqueous solution was added to the above reaction solution and stirred for 12 hours to perform the reduction treatment of Ni. Next, the completed reaction solution was transferred to a separatory funnel, the lower aqueous layer was removed, and then 100 mL of a 30% aqueous solution of isopropyl alcohol was added and the mixture was vigorously stirred. After standing to allow complete two-layer separation, the aqueous layer was removed. This washing process was repeated a total of three times, and then the oil layer was dropped into a large excess of acetone to reprecipitate the resulting polymer. After separating the polymer from the filtrate by filtration, the polymer was heated and dried in a vacuum dryer set to 60°C for 12 hours to obtain resin (A-2) having a norbornene skeleton. The weight-average molecular weight (Mw) of resin (A-2) having a norbornene skeleton, as measured by GPC, was 70,000, and the refractive index of resin (A-2) having a norbornene skeleton, as measured by an Abbe refractometer at 23°C and 589 nm, was 1.56.

[0102] (Synthesis of resin (A-3)) In a reaction vessel of appropriate size equipped with a stirrer and condenser, 45.1 g (0.25 mol) of 2-[(bicyclo[2.2.1]hepta-5-en-2-ylmethoxy)methyl]oxirane, 58.6 g (0.25 mol) of n-decylnorbornene, 107.5 g (0.6 mol) of N-cyclohexylmaleimide, and 2.3 g (0.01 mol) of dimethyl 2,2'-azobis(2-methylpropionate) were weighed and dissolved in 263 g of methyl ethyl ketone and 113 g of toluene. After removing dissolved oxygen from the system by nitrogen bubbling, the vessel was sealed and reacted at 70°C for 16 hours. The resulting solution was cooled to room temperature and then reprecipitation in a large amount of heptane to obtain a polymer precipitate. Next, the polymer was filtered off using a suction filter, and the powder was further washed with heptane. After that, it was dried in a dryer at 60°C for 24 hours to obtain a resin (A-3) having a norbornene skeleton. The weight-average molecular weight (Mw) of resin (A-3) having a norbornene skeleton, as measured by GPC, was 8,500, and the refractive index of resin (A-3) having a norbornene skeleton, as measured by Abbe refractometer at 23°C and 589 nm, was 1.51.

[0103] (Synthesis of resin (A-4)) A reaction vessel equipped with a stirrer and condenser was prepared. First, the inside was thoroughly purged with nitrogen. Then, 124.8 g (0.7 mol) of n-hexylnorbornene, 54.1 g (0.3 mol) of 2-[(bicyclo[2.2.1]hepta-5-en-2-ylmethoxy)methyl]oxirane, and 440 g of toluene were charged, and the mixture was heated to 50°C in an oil bath while stirring. A solution of (toluene)Ni(C6F5) 29.9 g (0.02 mol) dissolved in 5 g of toluene was added, and the reaction was continued at 50°C for 3 hours. The resulting solution was reprecipitation in a large amount of methanol to obtain a polymer precipitate, which was then filtered using a suction filter to obtain a polymer powder. The obtained polymer was vacuum-dried at 60°C for 16 hours to obtain a resin (A-4) having a norbornene skeleton. The weight-average molecular weight (Mw) of the resin (A-4) having a norbornene skeleton, as measured by GPC, was 50,000, and the refractive index of the resin (A-4) having a norbornene skeleton, as measured by an Abbe refractometer at 23°C and 589 nm, was 1.51.

[0104] (Synthesis of resin (A-5)) In a reaction vessel of appropriate size equipped with a stirrer and condenser, 470.8 g (5.0 mol) of 2-norbornene, 490.3 g (5.0 mol) of maleic anhydride, and 23.0 g (0.10 mol) of dimethyl 2,2'-azobis(2-methylpropionate) were weighed and dissolved in 1607 g of methyl ethyl ketone and 689 g of toluene. After removing dissolved oxygen from the system by nitrogen bubbling, the vessel was sealed and reacted at 70°C for 16 hours. After the resulting solution was cooled to room temperature, it was reprecipitation in a large amount of heptane to obtain a polymer precipitate. Subsequently, the polymer was filtered off using a suction filter, and the powder was further washed with heptane. The mixture was then dried in a dryer at 60°C for 24 hours to obtain a resin (A-5) having a norbornene skeleton. The weight-average molecular weight (Mw) of the resin (A-5) having a norbornene skeleton was 11,000, as measured by GPC, and the refractive index was 1.51 under conditions of 23°C and 589 nm, as measured by an Abbe refractometer.

[0105] The details of the raw materials for each component in Tables 1 and 2 are as follows:

[0106] <Resin (A)> (A-1) The resin synthesized above (A-2) The resin synthesized above (A-3) The resin synthesized above (A-4) The resin synthesized above (A-5) The resin synthesized above

[0107] [ka]

[0108] <Compound having a cyclic ether structure (B)> (B-1)OXT-221 (manufactured by Toagosei Co., Ltd., bifunctional oxetane compound, refractive index 1.45, liquid at 23°C) (B-2)OXT-212 (manufactured by Toagosei Co., Ltd., monofunctional oxetane compound, refractive index 1.44, liquid at 23°C) (B-3) Celoxide 2021P (manufactured by Daicel Corporation, bifunctional epoxy compound, refractive index 1.51, liquid at 23°C) (B-4) Celoxide 2000 (manufactured by Daicel Corporation, monofunctional epoxy compound, refractive index 1.51, liquid at 23°C) (B-5) JER-YX8000 (manufactured by Mitsubishi Chemical Corporation, bifunctional epoxy compound, refractive index 1.52, liquid at 23°C)

[0109] [ka]

[0110] <Hardening agent (C)> (C-1) CPI-310B (manufactured by Sunapro Co., Ltd., photocationic polymerization initiator) (C-2) Curazole C11z (manufactured by Shikoku Chemicals Co., Ltd., imidazole compound)

[0111] <Antioxidant (D)> (D-1) Irganox 1076 (BASF, hindered phenol type antioxidant) (D-2) Irgafos168 (BASF, phosphorus-type antioxidant)

[0112] <Surfactant (E)> (E-1) BYK-333 (manufactured by Big Chemie Japan Co., Ltd., silicone-based surfactant)

[0113] <Organic solvent (F)> (F-1) Toluene (F-2) Propylene glycol monomethyl ether-2-acetate (PGMEA) (F-3) Methyl ethyl ketone (MEK)

[0114] [Examples 1-10 and Comparative Examples 1-3] <Preparation of resin composition> Each raw material, formulated according to Table 1, was stirred at room temperature until the raw materials were completely dissolved to obtain a solution. The solution was then filtered through a PTFE filter with a pore size of 0.2 μm to obtain the resin compositions of Examples 1-10 and Comparative Examples 1-3, respectively.

[0115] <Preparation of dry film> The resin compositions of Examples 1-10 and Comparative Examples 1-3 were coated onto a release-treated PET film using an applicator to achieve a dry film thickness of 40 μm. After coating, the films were placed in a 45°C dryer for 5 minutes to completely remove the solvent and form a coating. Finally, a PET cover film was attached to the surface of the resin layer formed by the resin composition to obtain the dry films of Examples 1-10 and Comparative Examples 1-3, respectively.

[0116] Hereinafter, the resin compositions and dry films of Examples 1-10 and Comparative Examples 1-3 may be referred to as Cores A-M, respectively.

[0117] [Clad A-D] <Preparation of resin compositions for cladding A to D> Clad A to D resin compositions were obtained in the same manner as the resin compositions of Examples 1 to 10 and Comparative Examples 1 to 3, except that the raw materials were formulated according to Table 2.

[0118] <Preparation of a film for forming the first cladding layer> The resin compositions of cladding A and B were applied to a polyethylene terephthalate substrate with a release treatment to a thickness of 38 μm using an applicator, with a varnish coating applied to achieve a dry thickness of 25 μm. After drying at 100°C for 10 minutes, an OPP cover film was attached to the surface of the resin layer formed by the resin composition to obtain dry films of cladding A and B (films for forming the first cladding layer), respectively.

[0119] <Preparation of a film for forming the second cladding layer> The resin compositions of cladding B, C, and D were applied to a 25 μm thick polyimide substrate using an applicator, with a varnish coating applied to achieve a dry thickness of 12 μm. After drying at 100°C for 10 minutes, an OPP cover film was attached to the surface of the resin layer formed by the resin composition to obtain dry films of cladding B, C, and D (films for forming the second cladding layer), respectively.

[0120] [Examples 11-20 and Comparative Examples 4-6] Hereinafter, the terms "film for forming the first cladding layer," "film for forming the core layer," and "film for forming the second cladding layer" refer to the types of dry films listed in Table 3, respectively.

[0121] <Fabrication of photoelectric composite substrates> A double-sided copper-clad laminate with a surface roughening treatment (surface reflectivity of 20% at 365 nm, measured by spectrophotometer) measuring 80 mm in width, 120 mm in length, and 50 μm in thickness was placed on a stainless steel plate. After peeling off the OPP cover film of the film for forming the first cladding layer, the double-sided copper-clad laminate was laminated using a vacuum laminator (manufactured by Nikko Materials Co., Ltd., model name: CVP-600) under the conditions of temperature: 80°C, pressure: 5.0 MPa, and time: 120 seconds, so that the first cladding resin layer in the film for forming the first cladding layer and the double-sided copper-clad laminate were in contact. A laminate A was obtained with the layer configuration of "double-sided copper-clad laminate / first cladding resin layer / PET substrate". Here, the PET substrate is a PET substrate derived from the film for forming the first cladding layer. Next, using a high-pressure mercury lamp, an integrated light intensity of 1000 mJ / cm² is applied to the entire film to form the first cladding layer in laminate A. 2 The exposure was performed under the following conditions.

[0122] After peeling off the PET substrate from laminate A and peeling off the PET cover film of the film for forming the core layer, the laminate was laminated using a vacuum laminator (manufactured by Nikko Materials Co., Ltd., model name: CVP-300) under the conditions of temperature: 60°C, pressure: 0.5 MPa, and time: 30 seconds, so that the first cladding resin layer in laminate A and the core forming resin layer in the film for forming the core layer were in contact. Laminate B was obtained with a layer structure of "double-sided copper-clad laminate / first cladding resin layer / core forming resin layer / PET substrate". Here, the PET substrate is a PET substrate derived from the film for forming the core layer. Next, the resin layer for core formation was exposed using a direct-writing exposure machine (SCREEN Corporation, product name: LI-9000) with an integrated light intensity of 80 mJ / cm². 2 Under these conditions, 20 line-and-space lines were created, each 9 cm long with an exposed area of ​​10 μm and an unexposed area of ​​50 μm. Subsequently, the PET substrate derived from the film for forming the core layer was peeled off, and the laminate B was heat-treated by heating it in an atmospheric oven at 50°C for 1 hour.

[0123] Next, after peeling off the OPP cover film of the film for forming the second cladding layer, the core-forming resin layer in laminate B and the second cladding resin layer in the film for forming the second cladding layer were laminated using a vacuum laminator (manufactured by Nikko Materials Co., Ltd., model name: CVP-300) under the conditions of temperature: 80°C, pressure: 0.5 MPa, and time: 120 seconds, so that they were in contact. A laminate C was obtained with the layer configuration of "double-sided copper-clad laminate / first cladding resin layer / core-forming resin layer / second cladding resin layer / polyimide substrate". Here, the polyimide substrate is a polyimide substrate derived from the film for forming the second cladding layer.

[0124] The obtained laminate C was heated in an air oven at 125°C for 1 hour, followed by 180°C for 1 hour, to obtain the photoelectric composite substrates for Examples 11-20 and Comparative Examples 4-6, respectively. The layer structure of the obtained photoelectric composite substrates was "double-sided copper-clad laminate / first cladding layer / core layer / second cladding layer / polyimide substrate".

[0125] [evaluation] The evaluations of the dry films of Examples 1-10 and Comparative Examples 1-3, as well as the photoelectric composite substrates of Examples 11-20 and Comparative Examples 4-6, are described below.

[0126] <Refractive index> The PET cover film was peeled off the dry films of Examples 1-10 and Comparative Examples 1-3, and the refractive index was measured at 23°C and 589 nm using an Abbe refractometer (manufactured by Atago Co., Ltd., product name: NAR-1T SOLID). The results are shown in Table 1.

[0127] <Light transmittance for a wavelength of 850nm> For the dry films of Examples 1-10 and Comparative Examples 1-3, the PET cover film was peeled off, and the films were laminated onto a slide glass with the resin layer formed by the resin composition facing the slide glass side under the conditions of temperature: 100°C, pressure: 0.5 MPa, and time: 2 minutes. After that, the base film was peeled off to obtain a sample for transmittance measurement (slide glass with resin composition). Subsequently, a 100% correction was performed using a UV-Vis spectrophotometer (JASCO Corporation, product name: V-670) with slide glass placed in both the background slot and the sample slot. The slide glass on the measurement slot side was then replaced with the transmittance measurement sample, and the light transmittance [%] at a wavelength of 850 nm was measured in transmittance measurement mode. The results are shown in Table 1.

[0128] <Evaluation of dry film warpage> Dry films from Examples 1-10 and Comparative Examples 1-3 were cut into 10cm x 10cm pieces and used as samples for evaluating warpage. After removing the PET cover film from the samples, the core resin composition layer was placed face up and left on a flat surface for 5 minutes. The vertical distance between the vertices of the samples and the surface was measured. The vertical distance from the surface was measured at each of the four vertices of the sample, and the average value was evaluated as the amount of warpage of the dry film. Here, since the sample is rectangular, the four vertices of the sample refer to the four corners of the rectangle. Samples with a dry film curvature of 5 mm or less were classified as A, and samples with a curvature greater than 5 mm were classified as B. The results are shown in Table 1.

[0129] <Evaluation of optical loss> For the photoelectric composite substrates of Examples 11-20 and Comparative Examples 4-6, both sides were diced so that the patterned portion had a length of 7 cm, and samples for optical loss evaluation were obtained. For the samples used for optical loss evaluation, propagation loss was assessed in accordance with the cutback method described in section 4.6.2.1 of the "Test Method for Polymer Optical Waveguides (JPCA-PE02-05-01S-2008)". Light with a wavelength of 850 nm was used for the measurements. Based on the results, samples with propagation loss less than 1 dB were classified as A, samples with propagation loss between 1 dB and 3 dB as B, and samples with propagation loss exceeding 3 dB as C. The results are shown in Table 3.

[0130] <Pattern distortion evaluation after reflow> The photoelectric composite substrates from Examples 11-20 and Comparative Examples 4-6 were processed three times in an N2 reflow apparatus at a maximum temperature of 250°C. Subsequently, both sides were cut using a dicing apparatus so that the pattern length was 7 cm, and these were used as samples for evaluating the pattern distortion after reflow. The pattern shape of reflow-processed pattern distortion evaluation samples was evaluated by passing light with a wavelength of 850 nm through them. Samples in which no pattern distortion was observed were evaluated as A, and samples in which pattern distortion occurred were evaluated as B. The results are shown in Table 3.

[0131] [Table 1]

[0132] [Table 2]

[0133] [Table 3]

[0134] Table 1 shows that the dry films of the examples all exhibited good evaluation of dry film warpage. In other words, the resin composition of this embodiment can reduce the warpage of the resulting dry film. [Explanation of Symbols]

[0135] 20. First cladding layer 30 core layers 40. Second cladding layer 100 optical waveguide 110 circuit boards 200 Optoelectronic composite substrate

Claims

1. A resin composition that can be used in optical waveguides, The present invention comprises a resin (A) having a norbornene skeleton and a compound (B) having a cyclic ether structure. The resin composition wherein the content of the compound (B) having the cyclic ether structure in the resin composition is 34 parts by mass or more and 100 parts by mass or less, when the content of the resin (A) having the norbornene skeleton in the resin composition is 100 parts by mass.

2. The resin composition according to claim 1, wherein the compound (B) having the cyclic ether structure comprises at least one selected from the group consisting of oxetane compounds (B1) and epoxy compounds (B2).

3. The compound (B) having the cyclic ether structure comprises an oxetane compound (B1) and an epoxy compound (B2). The resin composition according to claim 1 or 2, wherein the mass ratio (B1 / B2) of the content of the oxetane compound (B1) in the resin composition to the content of the epoxy compound (B2) in the resin composition is 3.0 or more.

4. The compound (B) having the cyclic ether structure includes an oxetane compound (B1), The resin composition according to claim 1 or 2, wherein the oxetane compound (B1) comprises a polyfunctional oxetane compound.

5. The resin composition according to claim 1 or 2, wherein the compound (B) having the cyclic ether structure comprises a compound that is liquid at 23°C.

6. The resin composition according to claim 1 or 2, wherein the content of the bifunctional oxetane compound having an aromatic ring in the compound (B) having a cyclic ether structure is less than 5 parts by mass when the content of the compound (B) having a cyclic ether structure in the resin composition is 100 parts by mass.

7. The resin composition according to claim 1 or 2, wherein the content of the bifunctional epoxy compound having an aromatic ring in the compound (B) having a cyclic ether structure is less than 5 parts by mass when the content of the compound (B) having a cyclic ether structure in the resin composition is 100 parts by mass.

8. The resin composition according to claim 1 or 2, wherein the resin (A) having a norbornene skeleton includes a resin having an aromatic ring.

9. The resin composition according to claim 1 or 2, wherein the total content of the resin having a norbornene skeleton (A) and the compound having a cyclic ether structure (B) in the resin composition is 50% by mass or more, when the total amount of nonvolatile components in the resin composition is 100% by mass.

10. The resin composition according to claim 1 or 2, further comprising a photosensitive agent (C).

11. The resin composition according to claim 1 or 2, wherein the refractive index is 1.51 or more and 1.60 or less.

12. The resin composition according to claim 1 or 2, which is a resin composition that can be used in the core layer of an optical waveguide.

13. A dry film comprising a resin layer made of the resin composition according to claim 1 or 2.

14. The dry film according to claim 13, wherein the light transmittance of the resin layer for a wavelength of 850 nm is 85% or more.

15. An optical waveguide comprising a core layer and a cladding layer, An optical waveguide in which at least one of the core layer and the cladding layer is a layer comprising the resin composition according to claim 1 or 2.

16. circuit board and An optoelectronic composite substrate comprising an optical waveguide according to claim 15 provided on the substrate.

17. An electronic component comprising the optoelectronic composite substrate described in claim 16.

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