Photosensitive resin composition

Abstract

Provided is a photosensitive resin composition for manufacturing an optical waveguide, the composition being capable of manufacturing an optical waveguide having excellent processability. The photosensitive resin composition for manufacturing an optical waveguide includes an organopolysiloxane satisfying both of the following requirements (ɑ) and (β), or a combination of an organopolysiloxane satisfying only the requirement (ɑ) and an organopolysiloxane satisfying only the requirement (β). Requirement (ɑ): containing at least one among a T unit having a structure in which three siloxane bonds and one organic group are bonded to one silicon atom, a Q unit having a structure in which four siloxane bonds are bonded to one silicon atom, and a cyclic siloxane structure. Requirement (β): containing an epoxy group, and having a refractive index of less than 1.5 for a cured product at a wavelength of 1,310 nm.

Description

Photosensitive resin composition

[0001] This invention relates to a photosensitive resin composition for manufacturing optical waveguides. Furthermore, it relates to a set of photosensitive resin compositions, optical waveguides, a method for manufacturing optical waveguides, and a photoelectric mixed-signal substrate.

[0002] Technological advancements such as 5G communication, autonomous driving, IoT, artificial intelligence, and big data are driving increased demand for ultra-high-speed and high-capacity communications. The semiconductor packages that underpin these advancements have traditionally supported high-speed communication by passing high-frequency currents. However, in recent years, issues such as noise generation, communication loss, and heat generation due to high-speed communication have become apparent. To address these challenges, efforts to achieve energy savings, low latency, and high-speed communication using Co-Packaged Optics (CPO), which integrates optical circuits onto electrical wiring boards, have become increasingly popular.

[0003] In data centers, where high-speed transmission is particularly required, research into the introduction of silicon photonics is being actively pursued. Silicon photonics is highly compatible with conventional LSI manufacturing processes. Therefore, it is expected that by utilizing silicon photonics, it will be possible to form nanometer-sized fine-wire waveguides at low cost, based on the technologies cultivated in electronic circuit integration technology.

[0004] For example, in silicon photonics, it is expected that optical integrated circuits will be formed on chips using fine waveguides. When manufacturing an optoelectronic mixed-signal substrate on which such chips are mounted, it is necessary to provide optical waveguides on the optoelectronic mixed-signal substrate in order to extract signal light from the fine waveguides within the chip to the outside of the chip and connect it to the wiring between chips. From the viewpoint of efficiently forming fine optical waveguides, it is desirable to form the optical waveguides using a cured resin composition (for example, a photosensitive resin composition).

[0005] Among the components of photosensitive resin compositions for optical waveguide manufacturing, organopolysiloxanes, which are resins possessing various properties, are attracting attention. Examples of organopolysiloxanes are disclosed in Patent Documents 1 and 2.

[0006] International Publication No. 2018 / 199305, Japanese Patent Publication No. 2022-100721

[0007] However, the inventors have found that when optical waveguides are manufactured using a conventional photosensitive resin composition containing organopolysiloxane, the end faces become rough when the optical waveguides are cut, resulting in optical waveguides with poor processability.

[0008] The present invention has been made in view of the above, and aims to provide a photosensitive resin composition for manufacturing optical waveguides that provides optical waveguides with excellent processability; a resin composition for cladding containing the photosensitive resin composition; a set of photosensitive resin compositions containing the photosensitive resin composition; an optical waveguide containing a cured product of the photosensitive resin composition; a method for manufacturing the optical waveguide; and a photoelectric mixed-signal substrate equipped with the optical waveguide.

[0009] The inventors diligently studied to solve the above problems. As a result, the inventors found that the above problems can be solved by using a photosensitive resin composition containing an organopolysiloxane that satisfies specific requirements, and thus completed the present invention. That is, the present invention includes the following.

[0010] <1> A photosensitive resin composition for manufacturing optical waveguides, comprising an organopolysiloxane that satisfies both requirement (α) and requirement (β) below, or a combination of an organopolysiloxane that satisfies only requirement (α) of the following requirements (α) and requirement (β) below, and an organopolysiloxane that satisfies only requirement (β) of the following requirements (α) and requirement (β). Requirement (α): Contains at least one of a T unit, in which one silicon atom is bonded to three siloxane bonds and one organic group; a Q unit, in which one silicon atom is bonded to four siloxane bonds; and a cyclic siloxane structure. Requirement (β): Contains an epoxy group, and the refractive index of the cured product at a wavelength of 1310 nm is less than 1.5. <2> The photosensitive resin composition according to <1>, comprising an organopolysiloxane that satisfies both requirement (α) and requirement (β). <3> A photosensitive resin composition according to <1>, comprising a combination of an organopolysiloxane that satisfies only requirement (α) among requirement (α) and requirement (β), and an organopolysiloxane that satisfies only requirement (β) among requirement (α) and requirement (β). <4> A photosensitive resin composition according to any one of <1> to <3>, wherein requirement (β) further requires that the epoxy group contains an alicyclic epoxy group. <5> A photosensitive resin composition according to any one of <1> to <4>, wherein requirement (α) and requirement (β) or both further require that the molecule does not contain an aromatic ring. <6> A photosensitive resin composition according to any one of <1> to <5>, wherein requirement (α) and requirement (β) or both further require that the molecule does not contain a fluorine atom. <7> A photosensitive resin composition according to any one of <1> to <6>, further comprising a photopolymerization initiator. <8> The photosensitive resin composition according to <7>, wherein the photopolymerization initiator comprises a photoacid generator. <9> The photosensitive resin composition according to any one of <1> to <8>, further comprising a silane coupling agent. <10> The photosensitive resin composition according to any one of <1> to <9>, further comprising an organic solvent.<11> A photosensitive resin composition according to any one of <1> to <10>, wherein the cured product of the photosensitive resin composition has a refractive index of less than 1.5 at a wavelength of 1310 nm. <12> A cladding resin composition comprising the photosensitive resin composition according to any one of <1> to <11>. <13> A photosensitive resin composition set comprising a core resin composition and a cladding resin composition, wherein the core resin composition and the cladding resin composition each comprise the photosensitive resin composition according to any one of <1> to <11>. <14> A photosensitive resin composition set comprising a core resin composition and a cladding resin composition, wherein the core resin composition comprises the photosensitive resin composition according to <10>, and the cladding resin composition comprises the photosensitive resin composition according to any one of <1> to <11>. <15> A photosensitive resin composition set comprising a core resin composition and a cladding resin composition, wherein the core resin composition comprises the photosensitive resin composition described in any one of <1> to <11>, and the cladding resin composition comprises the photosensitive resin composition described in <9>. <16> An optical waveguide comprising a core layer and a cladding layer, wherein the core layer and the cladding layer each comprise a cured product of the photosensitive resin composition described in any one of <1> to <11>. <17> A photoelectric mixed substrate comprising the optical waveguide described in <16>. <18> A method for manufacturing an optical waveguide, comprising in this order: forming a first resin composition layer containing a cladding resin composition; curing the first resin composition layer; forming a second resin composition layer containing a core resin composition on the first resin composition layer; subjecting the second resin composition layer to exposure treatment; subjecting the second resin composition layer to development treatment; curing the second resin composition layer; forming a third resin composition layer containing a cladding resin composition on the second resin composition layer; and curing the third resin composition layer, wherein the core resin composition and the cladding resin composition contain the photosensitive resin composition described in any one of <1> to <11>.<19> A method for manufacturing an optical waveguide, comprising in this order: forming a first resin composition layer containing a cladding resin composition; curing the first resin composition layer; forming a second resin composition layer containing a core resin composition on the first resin composition layer; subjecting the second resin composition layer to exposure treatment; subjecting the second resin composition layer to development treatment; curing the second resin composition layer; forming a third resin composition layer containing a cladding resin composition on the second resin composition layer; and curing the third resin composition layer, wherein the core resin composition and the cladding resin composition contain the photosensitive resin composition described in any one of <1> to <11>, and the second resin composition layer contains the photosensitive resin composition described in <10>. <20> A method for manufacturing an optical waveguide, comprising in this order: forming a first resin composition layer containing a cladding resin composition; curing the first resin composition layer; forming a second resin composition layer containing a core resin composition on the first resin composition layer; subjecting the second resin composition layer to exposure treatment; subjecting the second resin composition layer to development treatment; curing the second resin composition layer; forming a third resin composition layer containing a cladding resin composition on the second resin composition layer; and curing the third resin composition layer, wherein the core resin composition and the cladding resin composition contain the photosensitive resin composition described in any one of <1> to <11>, and the first resin composition layer contains the photosensitive resin composition described in <9>.

[0011] According to the present invention, it is possible to provide: a photosensitive resin composition for manufacturing optical waveguides that provides optical waveguides with excellent processability; a resin composition for cladding containing the photosensitive resin composition; a set of photosensitive resin compositions containing the photosensitive resin composition; an optical waveguide containing a cured product of the photosensitive resin composition; a method for manufacturing the optical waveguide; and a photoelectric mixed-signal substrate equipped with the optical waveguide.

[0012] Figure 1 is a schematic perspective view showing an optical waveguide according to one embodiment of the present invention. Figure 2 is a schematic cross-sectional view illustrating step (1) of the method for manufacturing an optical waveguide according to one embodiment of the present invention. Figure 3 is a schematic cross-sectional view illustrating step (2) of the method for manufacturing an optical waveguide according to one embodiment of the present invention. Figure 4 is a schematic cross-sectional view illustrating step (3) of the method for manufacturing an optical waveguide according to one embodiment of the present invention. Figure 5 is a schematic cross-sectional view illustrating step (4) of the method for manufacturing an optical waveguide according to one embodiment of the present invention. Figure 6 is a schematic cross-sectional view illustrating step (5) of the method for manufacturing an optical waveguide according to one embodiment of the present invention. Figure 7 is a schematic cross-sectional view illustrating step (6) of the method for manufacturing an optical waveguide according to one embodiment of the present invention. Figure 8 is a schematic cross-sectional view illustrating step (7) of the method for manufacturing an optical waveguide according to one embodiment of the present invention. Figure 9 is a schematic cross-sectional view illustrating step (8) of the method for manufacturing an optical waveguide according to one embodiment of the present invention. Figure 10 is a schematic cross-sectional view illustrating step (9) of the method for manufacturing an optical waveguide according to one embodiment of the present invention.

[0013] The present invention will be described in detail below with reference to embodiments and examples. However, the present invention is not limited to the embodiments and examples described below, and can be modified and implemented as appropriate without departing from the scope of the claims and equivalents of the present invention.

[0014] [Explanation of Terms] The embodiments described herein may be used in combination with each other, regardless of expressions such as "preferred" or "more preferred." For example, the numerical range may be described using the upper and lower limits of each range, as well as a range combining the numerical values ​​of the examples.

[0015] In this specification, "non-volatile components" as used in reference to a resin composition refer to components of the resin composition other than the organic solvents described later.

[0016] In this specification, the term "may have substituents" when referring to a compound or group means, unless otherwise specified, both cases where the hydrogen atoms of the compound or group are not substituted by substituents, and cases where some or all of the hydrogen atoms of the compound or group are substituted by substituents. Furthermore, when the number of constituent atoms of a compound or group is stated, unless otherwise specified, the number of constituent atoms of substituents is not included. Furthermore, when the number of carbon atoms of a compound or group is stated, unless otherwise specified, the number of carbon atoms of substituents is not included.

[0017] In this specification, "organic group" means a group that includes at least one carbon atom as a skeletal atom, and may be linear, branched, or cyclic. In this specification, unless otherwise specified, the number of skeletal atoms in an organic group is preferably 1 to 3000, more preferably 1 to 1000, even more preferably 1 to 100, even more preferably 1 to 50, and even more preferably 1 to 30 or 1 to 20. Examples of organic groups include groups that include one or more skeletal atoms selected from carbon atoms, oxygen atoms, nitrogen atoms, and sulfur atoms (provided that at least one carbon atom is included). In embodiments in which the organic group includes non-skeletal atoms, the organic group may include a hydrogen atom as a non-skeletal atom, or a halogen atom (specifically, a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom). In such embodiments, it is preferable that the organic group includes only non-skeletal atoms selected from the group consisting of hydrogen atoms and halogen atoms other than fluorine atoms, and it is more preferable that the non-skeletal atoms include only hydrogen atoms (i.e., no halogen atoms as non-skeletal atoms).

[0018] In this specification, "aromatic ring" means a ring that obeys Hückel's rule, in which the number of electrons in the π-electron system on the ring is 4p + 2 (where p is an integer of 1 or more), and includes monocyclic aromatic rings and fused aromatic rings formed by the fusion of two or more monocyclic aromatic rings. Unless otherwise specified, monocyclic aromatic rings are preferred as aromatic rings. Aromatic rings can be aromatic carbocyclic rings having only carbon atoms as ring constituent atoms, or aromatic heterocyclic rings having heteroatoms such as oxygen atoms, nitrogen atoms, and sulfur atoms in addition to carbon atoms as ring constituent atoms. Unless otherwise specified, the number of carbon atoms in an aromatic ring is preferably 3 or more, more preferably 4 or more or 5 or more, and even more preferably 6 or more, with an upper limit of preferably 24 or less, more preferably 18 or less or 14 or less, and even more preferably 10 or less.

[0019] In this specification, the term "aromatic group" refers to a group obtained by removing one or more acyclic atoms (e.g., hydrogen atoms and / or halogen atoms) from the aromatic carbon that constitutes the aromatic ring of an aromatic compound. Here, a monovalent aromatic group refers to a group obtained by removing one acyclic atom from the aromatic carbon that constitutes the aromatic ring of an aromatic compound. Examples of monovalent aromatic groups include optionally substituted aryl groups and optionally substituted heteroaryl groups.

[0020] In this specification, "non-aromatic ring" means a ring other than an aromatic ring. A non-aromatic ring may be a non-aromatic carbon ring having only carbon atoms as ring constituent atoms, or it may be a non-aromatic hetero ring having heteroatoms such as oxygen atoms, nitrogen atoms, and sulfur atoms in addition to carbon atoms as ring constituent atoms. Non-aromatic carbon rings are preferred. A non-aromatic ring may be a saturated ring or an unsaturated ring. Non-aromatic rings with 3 to 21 members are preferred, non-aromatic rings with 4 to 17 members are more preferred, and non-aromatic rings with 5 to 14 members are even more preferred. Suitable examples of non-aromatic rings (non-aromatic carbon rings) include monocyclic non-aromatic saturated carbon rings such as cyclobutane rings, cyclopentane rings, cyclohexane rings, cycloheptane rings, and cyclooctane rings; monocyclic non-aromatic unsaturated carbon rings such as cyclobutene rings, cyclopentene rings, cyclohexene rings, cycloheptene rings, cyclooctene rings, cyclopentadiene rings, and cyclohexadiene rings; bicyclo[2.2.1]heptane rings (norbornane rings), bicyclo[4.4.0]decane rings (decalin rings), bicyclo[5.3.0]decane rings, bicyclo[4.3.0]nonane rings (hydrindan rings), bicyclo[3.2.1]octane rings, bicyclo[5.4.0]undecane rings, bicyclo[3.3.0]octane rings, bicyclo[3.3.1]nonane rings, and tricyclo[5.2.1.0] ２，６ ] Decane ring (tetrahydrodicyclopentadiene ring), tricyclo[3.3.1.1 ３，７ ] Decane ring (adamantane ring), tricyclo[6.2.1.0 ２，７ Examples of non-aromatic saturated carbocyclic rings with two or more rings, such as undecane rings; bicyclo[2.2.1]hepta-2-ene rings (norbornene rings), bicyclo[2.2.2]octa-2-ene rings, bicyclo[4.4.0]deca-2-ene rings, and other non-aromatic unsaturated carbocyclic rings with two or more rings. Non-aromatic rings may also be non-aromatic rings in which an aromatic ring is fused to a portion. Examples of non-aromatic rings in which an aromatic ring is fused to a portion include indane rings, indene rings, tetralin rings, 1,2-dihydronaphthalene rings, 1,4-dihydronaphthalene rings, fluorene rings, 9,10-dihydroanthracene rings, and 9,10-dihydrophenanthrene rings.

[0021] In this specification, the term "aliphatic group" refers to a group obtained by removing one or more non-skeletal atoms (e.g., hydrogen atoms or halogen atoms) bonded to the skeletal atoms (e.g., carbon atoms, or heteroatoms such as oxygen atoms, nitrogen atoms, or sulfur atoms) of an aliphatic compound. The aliphatic compound may be an aliphatic carbon compound having only carbon atoms as skeletal atoms, or it may be a heteroaliphatic compound having carbon atoms in addition to heteroatoms such as oxygen atoms, nitrogen atoms, or sulfur atoms as skeletal atoms. The aliphatic compound may contain hydrogen atoms as non-skeletal atoms, or it may contain halogen atoms. In embodiments in which the aliphatic group contains non-skeletal atoms, it is preferable that the aliphatic group contains only non-skeletal atoms selected from the group consisting of hydrogen atoms and halogen atoms other than fluorine atoms, and it is more preferable that the non-skeletal atoms consist only of hydrogen atoms (i.e., it does not contain halogen atoms as non-skeletal atoms). The aliphatic group may be linear, branched, or cyclic. The cyclic structure contained within a cyclic aliphatic group (in other words, the alicyclic structure) includes the non-aromatic rings mentioned above (excluding non-aromatic rings to which aromatic rings are partially fused). Here, a monovalent aliphatic group refers to a group from which one non-skeletal atom bonded to the skeletal atom of an aliphatic compound has been removed.

[0022] In this specification, "organopolysiloxane" means a polymer containing siloxane bonds, which are alternating bonds of silicon atoms (Si) and oxygen atoms (O), as repeating units, and in which some or all of the silicon atoms constituting the siloxane bonds are bonded to organic groups. In an organopolysiloxane, the repeating units may be the same or different from each other.

[0023] [Photosensitive Resin Composition] The photosensitive resin composition of the present invention is characterized by containing (I) an organopolysiloxane that satisfies both of the following requirements (α) and (β), or (II) a combination of an organopolysiloxane that satisfies only requirement (α) among the following requirements (α) and (β) (hereinafter sometimes simply referred to as "organopolysiloxane that satisfies only requirement (α)") and an organopolysiloxane that satisfies only requirement (β) among the following requirements (α) and (β) (hereinafter sometimes simply referred to as "organopolysiloxane that satisfies only requirement (β)"). Requirement (α): Contains at least one of a T unit, which is a structure in which one silicon atom is bonded to three siloxane bonds and one organic group; a Q unit, which is a structure in which one silicon atom is bonded to four siloxane bonds; and a cyclic siloxane structure. Requirement (β): Contains epoxy groups, and the refractive index of the cured product at a wavelength of 1310 nm is less than 1.5.

[0024] In the former embodiment (i.e., embodiment (I)), the organopolysiloxane satisfying both requirement (α) and requirement (β) may be used alone or in combination of two or more. In this embodiment, the photosensitive resin composition of the present invention may also contain, in addition to the organopolysiloxane satisfying both requirement (α) and requirement (β), one or more selected from the group consisting of organopolysiloxanes satisfying only requirement (α) and organopolysiloxanes satisfying only requirement (β). Here, the organopolysiloxane satisfying only requirement (α) may be used alone or in combination of two or more. Also, the organopolysiloxane satisfying only requirement (β) may be used alone or in combination of two or more.

[0025] In the latter embodiment of the present invention (i.e., embodiment (II)), an organopolysiloxane satisfying only requirement (α) may be used alone or in combination of two or more. Furthermore, in such an embodiment, an organopolysiloxane satisfying only requirement (β) may be used alone or in combination of two or more.

[0026] In this specification, when a photosensitive resin composition is said to contain an organopolysiloxane that satisfies specific requirements, unless otherwise specified, this encompasses both cases where the photosensitive resin composition contains an organopolysiloxane in aspect (I) and cases where the photosensitive resin composition contains an organopolysiloxane in aspect (II). When an optical waveguide is manufactured using the photosensitive resin composition of the present invention containing an organopolysiloxane that satisfies the above specific requirements, the end face is less likely to become rough when the optical waveguide is cut, thus providing an optical waveguide with excellent processability.

[0027] Regarding the measurement of the refractive index of cured products of individual organopolysiloxanes that satisfy the above specific requirements, the refractive index of the cured product at a wavelength of 1310 nm can be measured by the methods described in (1-1) to (1-5) below. (1-1): A mixture is obtained by adding 0.2% by mass of a photopolymerization initiator to 100% by mass of each organopolysiloxane. (1-2): The mixture (or, if necessary, a resin varnish obtained by dissolving the mixture in an organic solvent) is applied to the flat surface of a component having a surface, such as a silicon wafer, to obtain a resin layer with a thickness of 10 μm. (1-3): The formed resin layer is exposed to light at a wavelength of 365 nm and an illuminance of 35 mW / cm². ２ and 5J / cm ２ Exposure treatment is performed under the following conditions: (1-4): After exposure, the resin layer is subjected to a heat treatment at 190°C for 90 minutes in an atmospheric environment to cure the resin layer. (1-5): The cured resin layer obtained is measured at a measurement wavelength of 1310 nm, room temperature (25°C), and atmospheric pressure (1 atm). Note that if various conditions such as the type and amount of photopolymerization initiator, (if necessary, the amount of organic solvent used when preparing the resin varnish), the wavelength and amount of light in the exposure treatment, and the heating temperature and heating time in the heat treatment after exposure are changed, the coefficient of variation of the refractive index due to such changes in conditions is 0.5% or less.

[0028] The photopolymerization initiator used in step (1-1) above can be appropriately selected according to the type of each component to be measured for refractive index. For example, the components described in the section on <Photopolymerization Initiators> below can be used as photopolymerization initiators.

[0029] When the photosensitive resin composition of the present invention contains a plurality of organopolysiloxanes that satisfy the above specific requirements, among the cured products of each organopolysiloxane monomer that satisfies the above specific requirements, the maximum value of the refractive index is n ｍａｘ and the minimum value of the refractive index is n ｍｉｎ When, the difference n ｍａｘ - n ｍｉｎ of the refractive index is preferably less than 0.07, more preferably 0.05 or less, still more preferably 0.03 or less, and even more preferably 0.01 or less. The difference n ｍａｘ - n ｍｉｎ of the refractive index may have a lower limit of 0 or may be greater than 0. When the difference n ｍａｘ - n ｍｉｎ of the refractive index is within the above range, the compatibility of each organopolysiloxane that satisfies the above specific requirements in the photosensitive resin composition can be improved, resulting in an optical waveguide with excellent processability and further reducing the value of optical transmission loss in the optical waveguide.

[0030] The photosensitive resin composition of the present invention may further contain, as optional components, a photoinitiator, a photosensitizer, a silane coupling agent, other organopolysiloxanes, an epoxy resin, an organic solvent, and other additives. Hereinafter, each component contained in the resin composition of the present invention will be described in detail.

[0031] <Organopolysiloxane> The photosensitive resin composition of the present invention contains an organopolysiloxane that satisfies both requirement (α) and requirement (β), or a combination of an organopolysiloxane that satisfies only requirement (α) and an organopolysiloxane that satisfies only requirement (β).

[0032] - Requirement (α) - Requirement (α) relates to the siloxane structure of the organopolysiloxane. Specifically, requirement (α) requires containing at least one of a T unit having a structure in which three siloxane bonds and one organic group are bonded to one silicon atom, a Q unit having a structure in which four siloxane bonds are bonded to one silicon atom, and a cyclic siloxane structure.

[0033] In requirement (α), the T unit, as mentioned above, refers to a structure in which one silicon atom is bonded to three siloxane bonds and one organic group. Therefore, the T unit is a structure represented by the following formula (α-1).

[0034]

[0035] (In formula (α-1), R １ (The symbol represents a monovalent organic group; the wavy line represents the bonding site with the silicon atom.)

[0036] In equation (α-1), R １ R represents a monovalent organic group. １ The monovalent organic group represented by is not particularly limited and may contain, for example, one or more of the following: an epoxy group, a group that reacts with an epoxy group to form a crosslinked structure, and a radical polymerizable group. １ The monovalent organic group represented by preferably does not contain a fluorine atom, and also preferably does not contain an aromatic ring.

[0037] Examples of groups that react with epoxy groups to form crosslinked structures include highly reactive ester groups such as phenol esters, thiophenol esters, N-hydroxyamine esters, and esters of heterocyclic hydroxy compounds; hydroxyl groups (phenolic hydroxyl groups) bonded to aromatic rings such as benzene rings and naphthalene rings; groups containing carbodiimide structures; cyanate groups; groups containing benzoxazine rings; acid anhydride groups; amino groups; mercapto groups; and others. Among these, groups that react with epoxy groups to form crosslinked structures preferably do not contain fluorine atoms and preferably do not contain aromatic rings.

[0038] A radical polymerizable group is a group containing a radically polymerizable ethylenically unsaturated bond. Ethylenelycol unsaturated bonds do not include reaction-inert unsaturated bonds that constitute aromatic groups such as benzene rings. Examples of radical polymerizable groups include unsaturated hydrocarbon groups such as vinyl groups, propenyl groups (allyl group, 1-propenyl group, isopropenyl group), butenyl groups (1-butenyl group, clotyl group, methallyl group, isoclotyl group, etc.), pentenyl groups (1-pentenyl group, etc.), hexenyl groups (1-hexenyl group, etc.), cyclopentenyl groups (2-cyclopentenyl group, etc.), and cyclohexenyl groups (3-cyclohexenyl group, etc.); and α,β-unsaturated carbonyl groups such as acryloyl groups, methacryloyl groups, and maleimide groups (2,5-dihydro-2,5-dioxo-1H-pyrrole-1-yl group). In particular, the radical polymerizable group preferably does not contain a fluorine atom, and also preferably does not contain an aromatic ring.

[0039] Regarding requirement (α), if the organopolysiloxane contains T units, the T unit content (mol%) in the organopolysiloxane is preferably 10 mol% or more, more preferably 30 mol% or more, and even more preferably 45 mol% or more or 50 mol% or more, based on 100 mol% of total silicon atoms. The upper limit of such T unit content (mol%) is, for example, less than 100 mol%, preferably 90 mol% or less, more preferably 75 mol% or less, and even more preferably 60 mol% or less.

[0040] Regarding requirement (α), if the organopolysiloxane contains T units, the organopolysiloxane may further contain M units and / or D units. Here, an M unit refers to a structure in which one silicon atom is bonded to one siloxane bond and three organic groups, and a D unit refers to a structure in which one silicon atom is bonded to two siloxane bonds and two organic groups. In an organopolysiloxane containing T units, the content ratio (mol%) of M units and / or D units is not particularly limited, as long as it satisfies the aforementioned content ratio (mol%) of T units.

[0041] Regarding requirement (α), it is preferable that the organopolysiloxane containing T units further contains D units as siloxane structures other than T units. In such preferred embodiments, the content of D units (mol%) is preferably 1 mol% or more, more preferably 10 mol% or more, even more preferably 25 mol% or more, even more preferably 40 mol% or more, preferably 90 mol% or less, more preferably 70 mol% or less, even more preferably 55 mol% or less or 50 mol% or less, with respect to 100 mol% of total silicon atoms.

[0042] When an organopolysiloxane containing a T unit further contains a D unit, it is preferable that the two organic groups constituting the D unit do not contain a fluorine atom and also do not contain an aromatic ring. Furthermore, the more preferable configuration of the two organic groups constituting the D unit differs depending on whether the organopolysiloxane further satisfies requirement (β).

[0043] If an organopolysiloxane containing a T unit further satisfies requirement (β), it is more preferable that at least one of the two organic groups constituting the D unit in the organopolysiloxane may contain an epoxy group. In such a more preferred embodiment, if the two organic groups constituting the D unit include organic groups other than epoxy groups, there are no particular restrictions on the organic groups other than epoxy groups, as long as they do not contain a fluorine atom and / or an aromatic ring.

[0044] If an organopolysiloxane containing a T unit does not satisfy requirement (β), the two organic groups constituting the D unit in the organopolysiloxane that it may contain are not particularly limited and may contain, for example, one or more of the following: an epoxy group, a group that reacts with an epoxy group to form a crosslinked structure (excluding those containing a fluorine atom and / or an aromatic ring), and a radical polymerizable group (excluding those containing a fluorine atom and / or an aromatic ring). The groups that react with an epoxy group to form a crosslinked structure and radical polymerizable groups are as described above.

[0045] In requirement (α), the Q unit, as mentioned above, refers to a structure in which four siloxane bonds are attached to one silicon atom. Therefore, the Q unit is a structure represented by the following formula (α-2).

[0046]

[0047] (In equation (α-2), the wavy line represents the bonding site with the silicon atom.)

[0048] Regarding requirement (α), if the organopolysiloxane contains Q units, the Q unit content (mol%) in the organopolysiloxane is preferably 10 mol% or more, more preferably 20 mol% or more, and even more preferably 25 mol% or more or 30 mol% or more, based on 100 mol% of total silicon atoms. The upper limit of such Q unit content (mol%) is preferably 70 mol% or less, more preferably 50 mol% or less, and even more preferably 40 mol% or less.

[0049] Regarding requirement (α), an organopolysiloxane containing Q units may also contain siloxane structures other than Q units. Therefore, an organopolysiloxane containing Q units may further contain M units, D units, and / or T units. The content percentage (mol%) of M units, D units, and / or T units in an organopolysiloxane containing Q units is not particularly limited, as long as it satisfies the aforementioned content percentage (mol%) of Q units.

[0050] Regarding requirement (α), it is preferable that the organopolysiloxane containing Q units further contains M units as siloxane structures other than Q units. In such preferred embodiments, the content of M units (mol%) is preferably 30 mol% or more, more preferably 50 mol% or more, even more preferably 60 mol% or more, preferably 90 mol% or less, more preferably 80 mol% or less, even more preferably 75 mol% or less or 70 mol% or less, based on 100 mol% of total silicon atoms.

[0051] When an organopolysiloxane containing Q units further contains M units, it is preferable that the three organic groups constituting the M unit do not contain a fluorine atom and also do not contain an aromatic ring. Furthermore, the more preferable configuration of the three organic groups constituting the M unit differs depending on whether the organopolysiloxane further satisfies requirement (β).

[0052] If the organopolysiloxane containing the Q unit further satisfies requirement (β), it is preferable that at least one of the three organic groups constituting the M unit in the organopolysiloxane may contain an epoxy group. In such a preferred embodiment, if the three organic groups constituting the M unit include organic groups other than epoxy groups, there are no particular restrictions on the organic groups other than epoxy groups, as long as they do not contain a fluorine atom and / or an aromatic ring.

[0053] If an organopolysiloxane containing Q units does not satisfy requirement (β), the M units that the organopolysiloxane may contain may contain one or more of the following three organic groups: an epoxy group, a group that reacts with an epoxy group to form a crosslinked structure (excluding those containing a fluorine atom and / or an aromatic ring), and a radical polymerizable group (excluding those containing a fluorine atom and / or an aromatic ring). The groups that react with an epoxy group to form a crosslinked structure and the radical polymerizable groups are as described above.

[0054] In requirement (α), a cyclic siloxane structure refers to a structure in which siloxane bonds in an organopolysiloxane are bonded in a cyclic manner. The siloxane bonds constituting the cyclic bond may consist of D units, T units, or Q units. Therefore, a cyclic siloxane structure is represented by the following formula (α-3).

[0055]

[0056] (In formula (α-3), R ２ , R ３ and R ４Each of the following independently represents a monovalent organic group; n1, n2, and n3 independently represent non-negative integers satisfying the relationship 2 ≤ n1 + n2 + n3; the dashed line represents the bonding site with the silicon atom; the n1 units may be the same or different for each unit; the n2 units may be the same or different for each unit; and the n3 units may be the same or different for each unit.

[0057] In equation (α-3), R ２ , R ３ and R ４ Each of these independently represents a monovalent organic group. ２ , R ３ and R ４ The monovalent organic groups represented by each preferably do not contain a fluorine atom and also preferably do not contain an aromatic ring. ２ , R ３ and R ４ The monovalent organic group represented by has different more preferred embodiments depending on whether the organopolysiloxane containing the cyclic siloxane structure further satisfies requirement (β).

[0058] If an organopolysiloxane containing a cyclic siloxane structure further satisfies requirement (β), R ２ , R ３ and R ４ It is more preferable that at least one of the groups represented by contains an epoxy group, R ２ and R ３ It is even more preferable that at least one of the groups represented by contains an epoxy group.

[0059] If an organopolysiloxane containing a cyclic siloxane structure does not meet requirement (β), R ２ , R ３ and R ４The monovalent organic group represented by may contain, for example, one or more of the following: an epoxy group, a group that reacts with an epoxy group to form a crosslinked structure (excluding those containing a fluorine atom and / or an aromatic ring), and a radical polymerizable group (excluding those containing a fluorine atom and / or an aromatic ring). The group that reacts with an epoxy group to form a crosslinked structure and the radical polymerizable group are as described above.

[0060] In the cyclic siloxane structure represented by formula (α-3), if it has two or more repeating units, the arrangement of the n1, n2, and n3 units is not particularly restricted and may be a block arrangement, a random arrangement, or an alternating arrangement.

[0061] The cyclic siloxane structure preferably contains D units (i.e., in formula (α-3) above, it is preferable that n1 ≥ 1), more preferably contains D units and the number of D units is greater than the sum of the number of T units and Q units (i.e., in formula (α-3) above, it is preferable that the proportion of n1 units, represented by [n1 ÷ (n1 + n2 + n3) × 100], is, for example, 50% or more, 60% or more, 70% or more, 80% or more, 90% or more, 95% or more, 99% or more, or 100%), and even more preferably contains only D units (i.e., in formula (α-3) above, it is preferable that n1 ≥ 2 and n2 = n3 = 0).

[0062] Therefore, in a preferred embodiment, an organopolysiloxane containing a cyclic siloxane structure is represented by the following formula (α-4).

[0063]

[0064] (In formula (α-4), R ５ , R ６ , R ７ and R ８Each of the n4 and n5 units independently represents a monovalent organic group; each of the n4 and n5 units independently represents a non-negative integer satisfying the relationship 2 ≤ n4 + n5; each n4 unit may be identical or different; each n5 unit may be identical or different; and the n4 and n5 units are distinct repeating units.

[0065] In equation (α-4), R ５ , R ６ , R ７ and R ８ Each of these independently represents a monovalent organic group. ５ , R ６ , R ７ and R ８ The monovalent organic groups represented by each preferably do not contain a fluorine atom and also preferably do not contain an aromatic ring. ５ , R ６ , R ７ and R ８ The monovalent organic group represented by has a more preferred embodiment depending on whether the organopolysiloxane represented by formula (α-4) further satisfies requirement (β).

[0066] If the organopolysiloxane represented by formula (α-4) further satisfies requirement (β), then R ５ , R ６ , R ７ and R ８ It is more preferable that at least one of the monovalent organic groups represented by contains an epoxy group, R ５ and R ７ It is even more preferable that at least one of the groups represented by contains an epoxy group. In such a more preferred embodiment, R ５ , R ６ , R ７ and R ８ If at least one of the monovalent organic groups represented by includes a monovalent organic group other than an epoxy group, there are no particular restrictions on the monovalent organic group other than the epoxy group, as long as it does not contain a fluorine atom and / or an aromatic ring.

[0067] If the organopolysiloxane represented by formula (α-4) does not satisfy requirement (β), R ５ , R ６ , R ７ and R ８ The monovalent organic group represented by is not particularly limited and may contain, for example, one or more of the following: an epoxy group, a group that reacts with an epoxy group to form a crosslinked structure (excluding those containing a fluorine atom and / or an aromatic ring), and a radical polymerizable group (excluding those containing a fluorine atom and / or an aromatic ring). The group that reacts with an epoxy group to form a crosslinked structure and the radical polymerizable group are as described above.

[0068] When the organopolysiloxane represented by formula (α-4) has both n4 and n5 repeating units (i.e., in formula (α-4), n4 ≥ 1 and n5 ≥ 1), the arrangement of the n4 and n5 units is preferably alternating.

[0069] In formula (α-4), n4 and n5 each independently represent integers greater than or equal to 0 and satisfy the relationship 2 ≤ n4 + n5. When the organopolysiloxane represented by formula (α-4) has both n4 and n5 repeating units (i.e., in formula (α-4), n4 ≥ 1 and n5 ≥ 1), n4 + n5 is preferably an integer between 3 and 20, more preferably an integer between 3 and 10, even more preferably an integer between 3 and 6, and even more preferably 4. Also, when the organopolysiloxane represented by formula (α-4) has only n4 units (i.e., in formula (α-4), n4 ≥ 2 and n5 = 0), n4 is preferably an integer between 3 and 20, more preferably an integer between 3 and 10, even more preferably an integer between 3 and 6, and even more preferably 4.

[0070] It is preferable that an organopolysiloxane satisfying requirement (α) does not contain radical polymerizable groups in its molecule. In other words, it is preferable that requirement (α) be further specified as not containing radical polymerizable groups in its molecule. Therefore, it is preferable that the organic groups constituting the organopolysiloxane satisfying requirement (α) do not contain radical polymerizable groups. In the embodiment in which an organopolysiloxane satisfying requirement (α) does not contain radical polymerizable groups in its molecule, when the photosensitive resin composition is subjected to exposure treatment, the curing reaction can proceed uniformly throughout the photosensitive resin composition compared to the embodiment in which radical polymerizable groups are contained. Therefore, the embodiment in which an organopolysiloxane satisfying requirement (α) does not contain radical polymerizable groups in its molecule is preferable because it can provide an optical waveguide with excellent processability while also providing an optical waveguide with excellent patternability.

[0071] It is preferable that an organopolysiloxane satisfying requirement (α) does not contain a fluorine atom in its molecule. In other words, it is preferable that requirement (α) be further specified as the absence of a fluorine atom in its molecule. Therefore, it is preferable that the organic group constituting the organopolysiloxane satisfying requirement (α) does not contain a fluorine atom (i.e., it contains only non-skeletal atoms selected from the group consisting of hydrogen atoms and halogen atoms other than fluorine atoms). Furthermore, it is even more preferable that the organic group constituting the organopolysiloxane satisfying requirement (α) contains only a hydrogen atom as a non-skeletal atom (i.e., it does not contain halogen atoms as non-skeletal atoms). Furthermore, it is even more preferable that the organic group constituting the organopolysiloxane satisfying requirement (α) is an organic group consisting of at least one carbon atom, plus one or more atoms selected from hydrogen atoms, carbon atoms, oxygen atoms, nitrogen atoms, and sulfur atoms. In particular, the embodiment in which the organopolysiloxane satisfying requirement (α) does not contain a fluorine atom in its molecule is preferable because, compared to the embodiment containing a fluorine atom, it can provide an optical waveguide with excellent processability while also providing an optical waveguide with excellent adhesion to the substrate.

[0072] It is preferable that the organopolysiloxane satisfying requirement (α) does not contain an aromatic ring in its molecule. In other words, it is preferable to further specify that requirement (α) does not contain an aromatic ring in its molecule. Therefore, it is preferable that the organic group constituting the organopolysiloxane satisfying requirement (α) is an aliphatic group. In the embodiment in which the organic group constituting the organopolysiloxane satisfying requirement (α) is an aliphatic group, the refractive index of the cured product of the photosensitive resin composition can be made relatively smaller compared to the embodiment in which the organic group contains an aromatic ring, and thus an optical waveguide with low optical transmission loss can be obtained. Therefore, the embodiment in which the organopolysiloxane satisfying requirement (α) does not contain an aromatic ring is preferable because it can provide an optical waveguide with low optical transmission loss while providing an optical waveguide with excellent processability.

[0073] An organopolysiloxane that satisfies requirement (α) preferably contains a cyclic siloxane structure, and more preferably contains a cyclic siloxane structure containing only D units. In other words, it is preferable to further require that requirement (α) contain a cyclic siloxane structure, and more preferably contain a cyclic siloxane structure containing only D units. An organopolysiloxane containing a cyclic siloxane structure (and moreover, a cyclic siloxane structure containing only D units) has a more flexible structure than an organopolysiloxane that does not contain a cyclic siloxane structure and an organopolysiloxane containing a cyclic siloxane structure containing at least one of T units and Q units. Therefore, it is possible to reduce the stress that may occur in the cured product of the photosensitive resin composition, and thus it is possible to further suppress the roughening of the end face when cutting the optical waveguide. Therefore, in embodiments of organopolysiloxanes that satisfy requirement (α) that contain a cyclic siloxane structure, and moreover, embodiments that contain a cyclic siloxane structure containing only D units, the stress that may occur when cutting the optical waveguide can be reduced compared to embodiments that do not contain a cyclic siloxane structure and embodiments that contain a cyclic siloxane structure containing at least one of T units and Q units, thus easily resulting in a photosensitive resin composition that provides an optical waveguide with particularly excellent processability, and is therefore preferable. Furthermore, organopolysiloxanes containing a cyclic siloxane structure (and moreover, cyclic siloxane structures containing only D units) can reduce steric hindrance caused by the organopolysiloxane and can improve the compatibility between the organopolysiloxane and other components compared to organopolysiloxanes that do not contain a cyclic siloxane structure and organopolysiloxanes that contain a cyclic siloxane structure containing at least one of T units and Q units. Consequently, if the photosensitive resin composition further contains any other component, the organopolysiloxane containing a cyclic siloxane structure (or even a cyclic siloxane structure containing only D units) will be more uniformly dispersed throughout the photosensitive resin composition, allowing the curing reaction to proceed more uniformly throughout the entire composition.Therefore, when the photosensitive resin composition contains an organopolysiloxane that satisfies the requirements (α) of the preferred embodiment described above, it is preferable because it can provide an optical waveguide with excellent patternability while also providing an optical waveguide with excellent processability.

[0074] -Requirement (β)- Requirement (β) relates to the functional groups of the organopolysiloxane and the refractive index of the cured product. Specifically, requirement (β) requires that the product contains epoxy groups and that the refractive index of the cured product at a wavelength of 1310 nm is less than 1.5.

[0075] In requirement (β), the refractive index of the cured organopolysiloxane at a wavelength of 1310 nm is preferably 1.4 or higher, more preferably 1.43 or higher, and even more preferably 1.44 or higher.

[0076] In requirement (β), the epoxy group is preferably selected from the group consisting of glycidyl ether groups and alicyclic epoxy groups, and more preferably contains alicyclic epoxy groups. That is, in a more preferred embodiment, requirement (β) is further required to contain alicyclic epoxy groups. In requirement (β), if the organopolysiloxane contains two or more alicyclic epoxy groups in one molecule, the alicyclic epoxy groups may be the same or different from each other.

[0077] An alicyclic epoxy group is an epoxy group in which one oxygen atom is bonded to two adjacent carbon atoms that constitute an alicyclic skeleton. An alicyclic skeleton is a skeleton consisting of non-aromatic rings. An alicyclic skeleton may have substituents in substitutable positions.

[0078] The alicyclic epoxy group is preferably an epoxy group in which one oxygen atom is bonded to two adjacent carbon atoms constituting a saturated carbon ring, and more preferably an epoxy group in which one oxygen atom is bonded to two adjacent carbon atoms constituting a cyclohexane ring.

[0079] Regarding requirement (β), the epoxy equivalent of the organopolysiloxane is preferably 50 g / eq. or more, more preferably 80 g / eq. or more, even more preferably 110 g / eq. or more, even more preferably 150 g / eq. or more, preferably 3,000 g / eq. or less, more preferably 2,000 g / eq. or less, even more preferably 1,000 g / eq. or less, and even more preferably 700 g / eq. or less. The epoxy equivalent of the organopolysiloxane that satisfies requirement (β) is the mass of the organopolysiloxane that satisfies requirement (β) per equivalent of epoxy group.

[0080] Regarding requirement (β), it is preferable to further specify that the molecule does not contain radical polymerizable groups. Therefore, it is preferable that the organic groups constituting the organopolysiloxane satisfying requirement (β) do not contain radical polymerizable groups. In such a preferred embodiment, the organic groups constituting the organopolysiloxane satisfying requirement (β) are not particularly limited, as long as they contain at least epoxy groups and do not contain radical polymerizable groups. In an embodiment in which the organopolysiloxane satisfying requirement (β) does not contain radical polymerizable groups in its molecule, when the photosensitive resin composition is subjected to exposure treatment, the curing reaction can proceed uniformly throughout the photosensitive resin composition compared to an embodiment in which radical polymerizable groups are contained. Therefore, an embodiment in which the organopolysiloxane satisfying requirement (β) does not contain radical polymerizable groups in its molecule is preferred because it can provide an optical waveguide with excellent processability while also providing an optical waveguide with excellent patternability.

[0081] Regarding requirement (β), it is preferable to further specify that the molecule does not contain fluorine atoms. Therefore, it is preferable that the organic groups constituting the organopolysiloxane satisfying requirement (β) do not contain fluorine atoms (i.e., they contain only non-skeletal atoms selected from the group consisting of hydrogen atoms and halogen atoms other than fluorine atoms). Furthermore, it is even more preferable that the organic groups constituting the organopolysiloxane satisfying requirement (β) contain only hydrogen atoms as non-skeletal atoms (i.e., they do not contain halogen atoms as non-skeletal atoms). Moreover, it is even more preferable that the organic groups constituting the organopolysiloxane satisfying requirement (β) are organic groups consisting of at least one carbon atom, plus one or more atoms selected from hydrogen atoms, carbon atoms, oxygen atoms, nitrogen atoms, and sulfur atoms. In particular, the embodiment in which the organopolysiloxane satisfying requirement (β) does not contain fluorine atoms in its molecule is preferable because, compared to the embodiment containing fluorine atoms, it can provide an optical waveguide with excellent processability while also providing an optical waveguide with excellent substrate adhesion.

[0082] Regarding requirement (β), it is preferable to further specify that the molecule does not contain an aromatic ring. Therefore, it is preferable that the organic group constituting the organopolysiloxane satisfying requirement (β) does not contain an aromatic ring. In such a preferred embodiment, the organic group constituting the organopolysiloxane satisfying requirement (β) is a group made of an aliphatic compound (i.e., an aliphatic group). The aliphatic compound may include any of linear, branched, or cyclic structures. In the embodiment in which the organic group constituting the organopolysiloxane satisfying requirement (β) is an aliphatic group, the refractive index of the cured product of the photosensitive resin composition can be made relatively smaller compared to the embodiment in which the organic group contains an aromatic ring, and thus an optical waveguide with low optical transmission loss can be obtained. Therefore, the embodiment in which the organopolysiloxane satisfying requirement (β) does not contain an aromatic ring is preferred because it can provide an optical waveguide with low optical transmission loss while providing an optical waveguide with excellent processability.

[0083] In particular, the photosensitive resin composition of the present invention is preferably further required to not contain radical polymerizable groups in its molecule in either or both of requirement (α) and requirement (β), and more preferably further required to not contain radical polymerizable groups in its molecule in both requirement (α) and requirement (β).

[0084] Furthermore, it is preferable that the photosensitive resin composition of the present invention further requires that it does not contain fluorine atoms in its molecule in one or both of requirements (α) and (β), and it is even more preferable that it further requires that it does not contain fluorine atoms in its molecule in both requirements (α) and (β).

[0085] Furthermore, it is preferable that the photosensitive resin composition of the present invention further requires that, in one or both of requirements (α) and (β), it is necessary to provide that the molecule does not contain an aromatic ring, and it is even more preferable that, in both requirements (α) and (β), it is necessary to provide that the molecule does not contain an aromatic ring.

[0086] As described above, the photosensitive resin composition of the present invention is characterized by (I) containing an organopolysiloxane that satisfies both requirement (α) and requirement (β), or (II) containing a combination of an organopolysiloxane that satisfies only requirement (α) and an organopolysiloxane that satisfies only requirement (β). As described above, in the former embodiment (embodiment of (I)), in addition to an organopolysiloxane that satisfies both requirement (α) and requirement (β), it may further contain one or more selected from the group consisting of an organopolysiloxane that satisfies only requirement (α) and an organopolysiloxane that satisfies only requirement (β).

[0087] Depending on whether the photosensitive resin composition of the present invention is the former embodiment (embodiment (I)) or the latter embodiment (embodiment (II)), the preferred amount of organopolysiloxane in the photosensitive resin composition that satisfies the above specific requirements may differ.

[0088] In the former embodiment (embodiment (I)), the content of organopolysiloxane in the photosensitive resin composition that satisfies both requirement (α) and requirement (β) is preferably 50% by mass or more, more preferably 75% by mass or more, and even more preferably 85% by mass or more or 87% by mass or more, based on 100% by mass of the nonvolatile components in the photosensitive resin composition, from the viewpoint of significantly obtaining the desired effects of the present invention. The upper limit of the content may be, for example, 100% by mass, less than 100% by mass, 99% by mass or less, 95% by mass or less, or 90% by mass or less.

[0089] Furthermore, in the former embodiment (embodiment (I)), if the photosensitive resin composition contains an organopolysiloxane that satisfies both requirement (α) and requirement (β), in addition to an organopolysiloxane that satisfies only requirement (α), the total amount of the organopolysiloxane that satisfies both requirement (α) and requirement (β) and the organopolysiloxane that satisfies only requirement (α) in the photosensitive resin composition is preferably 50% by mass or more, more preferably 75% by mass or more, and even more preferably 85% by mass or more or 87% by mass or more, based on 100% by mass of the nonvolatile components in the photosensitive resin composition. The upper limit of the total amount may be, for example, 100% by mass, less than 100% by mass, 99% by mass or less, 95% by mass or less, or 90% by mass or less.

[0090] Furthermore, in the former embodiment (embodiment (I)), if the photosensitive resin composition contains an organopolysiloxane that satisfies both requirement (α) and requirement (β), in addition to an organopolysiloxane that satisfies only requirement (β), the total amount of the organopolysiloxane that satisfies both requirement (α) and requirement (β) and the organopolysiloxane that satisfies only requirement (β) in the photosensitive resin composition is, from the viewpoint of significantly obtaining the desired effects of the present invention, preferably 50% by mass or more, more preferably 75% by mass or more, and even more preferably 85% by mass or more or 87% by mass or more, based on 100% by mass of the nonvolatile components in the photosensitive resin composition. The upper limit of the total amount may be, for example, 100% by mass, less than 100% by mass, 99% by mass or less, 95% by mass or less, or 90% by mass or less.

[0091] In the latter embodiment (embodiment (II)), the content of organopolysiloxane in the photosensitive resin composition that satisfies only requirement (α) is, from the viewpoint of significantly obtaining the desired effects of the present invention, preferably 10% by mass or more, more preferably 20% by mass or more, even more preferably 30% by mass or more or 35% by mass or more, preferably 70% by mass or less, more preferably 60% by mass or less, and even more preferably 50% by mass or less, based on 100% by mass of the nonvolatile components in the photosensitive resin composition.

[0092] In the latter embodiment (embodiment (II)), the content of organopolysiloxane in the photosensitive resin composition that satisfies only requirement (β) is, from the viewpoint of significantly obtaining the desired effects of the present invention, preferably 20% by mass or more, more preferably 30% by mass or more, even more preferably 40% by mass or more or 45% by mass or more, preferably 80% by mass or less, more preferably 70% by mass or less, and even more preferably 60% by mass or less, based on 100% by mass of the nonvolatile components in the photosensitive resin composition.

[0093] In the latter embodiment (embodiment (II)), the total amount of organopolysiloxane satisfying only requirement (α) and organopolysiloxane satisfying only requirement (β) in the photosensitive resin composition is, from the viewpoint of significantly obtaining the desired effects of the present invention, preferably 50% by mass or more, more preferably 75% by mass or more, even more preferably 85% by mass or more, even more preferably 90% by mass or more, 91% by mass or more, 92% by mass or more, or 93% by mass or more, based on 100% by mass of the nonvolatile components in the photosensitive resin composition. The upper limit of the total amount may be 100% by mass or less (for example, 99.5% by mass or less or 99% by mass or less).

[0094] Furthermore, in the latter embodiment (embodiment (II)), when the content of organopolysiloxane satisfying only requirement (α) is M(α) (mass%) relative to 100% by mass of the nonvolatile component in the photosensitive resin composition is M(β) (mass%), and the content of organopolysiloxane satisfying only requirement (β) is M(β) (mass%), the mass ratio M(β) / M(α) is preferably 0.5 or more, more preferably 0.7 or more, even more preferably 0.9 or more, preferably 5 or less, more preferably 3 or less, and even more preferably 2 or less, from the viewpoint of significantly obtaining the desired effects of the present invention.

[0095] <Photopolymerization Initiator> The photosensitive resin composition of the present invention may contain a photopolymerization initiator as an optional component. The photopolymerization initiator does not include organopolysiloxanes that meet the specific requirements described above. The photopolymerization initiator may be used alone or in combination of two or more types.

[0096] As photopolymerization initiators, photoradical generators and / or photoacid generators can be used. Among these, it is preferable that the photopolymerization initiator includes a photoacid generator.

[0097] As a photopolymerization initiator, a photoacid generator can be a compound that can generate acid upon irradiation with active light. Examples of photoacid generators include oxime ester compounds, halogen-containing compounds, onium salt compounds, diazoketone compounds, sulfone compounds, sulfonic acid compounds, sulfonimide compounds, diazomethane compounds, and diazoquinone compounds. Among these, it is preferable that the photoacid generator contains an onium salt compound.

[0098] Specific examples of oxime ester compounds that can be suitably used as photoacid generators include benzeneacetonitrile, 2-methyl-α-[2-[[(propylsulfonyl)oxy]imino]-3(2H)-thienylidene] and benzeneacetonitrile, 2-methyl-α-[2-[[[(4-methylphenyl)sulfonyl]oxy]imino]-3(2H)-thienylidene]. Commercially available products include, for example, BASF's "PAG103", "PAG121", "PAG169", and "PAG203".

[0099] Examples of halogen-containing compounds that can be used as photoacid generators include haloalkyl group-containing hydrocarbon compounds and haloalkyl group-containing heterocyclic compounds. Suitable specific examples of halogen-containing compounds include 2-[2-(furan-2-yl)ethenyl]-4,6-bis(trichloromethyl)-s-triazine, 2-[2-(5-methylfuran-2-yl)ethenyl]-4,6-bis(trichloromethyl)-s-triazine, 2-(methoxyphenyl)-4,6-bis(trichloromethyl)-s-triazine, 2-[2-(4-methoxyphenyl)ethenyl]-4,6-bis(trichloromethyl)-s-triazine, and 2-[2-(3,4-dimethylphenyl] Examples of s-triazine derivatives include s-triazine derivatives such as s(phenyl)ethenyl)-4,6-bis(trichloromethyl)-s-triazine, 1,10-dibromo-n-decane, 1,1-bis(4-chlorophenyl)-2,2,2-trichloroethane, phenyl-bis(trichloromethyl)-s-triazine, 4-methoxyphenyl-bis(trichloromethyl)-s-triazine, styryl-bis(trichloromethyl)-s-triazine, and naphthyl-bis(trichloromethyl)-s-triazine.

[0100] Specific examples of halogen-containing compounds include Sanwa Chemical's "TFE-triazine," "TME-triazine," "MP-triazine," "MOP-triazine," and "dimethoxytriazine" (halogen-containing compound photoacid generators having a triazine skeleton).

[0101] Examples of onium salt compounds that can be suitably used as photoacid generators include iodonium salts, sulfonium salts, phosphonium salts, diazonium salts, and pyridinium salts. Suitable examples of onium salt compounds include tris(4-methylphenyl)sulfonium trifluoromethanesulfonate, tris(4-methylphenyl)sulfonium hexafluorophosphonate, diphenyliodonium trifluoromethanesulfonate, diphenyliodonium p-toluenesulfonate, diphenyliodonium hexafluoroantimonate, diphenyliodonium hexafluorophosphate, diphenyliodonium tetrafluoroborate, triphenylsulfonium trifluilomethanesulfonate, triphenylsulfonium p-toluenesulfonate, triphenylsulfonium hexafluoroantimonate, 4-tert-butylphenyl / diphenylsulfonium trifluoromethanesulfonate, 4-tert-butylphenyl / diphenylsulfonium p-toluenesulfonate, and 4,7-di-n-butoxynaphthyltetrahydrothiophenium trifluilomethanesulfonate.

[0102] Commercially available onium salt compounds can be used. Examples of commercially available products include "TS-01" and "TS-91" from Sanwa Chemical Co., Ltd.; "CPI-110A," "CPI-210S," "HS-1," "LW-S1," "IK-1," "CPI-310B," and "CPI-310FG" from Sunapro Co., Ltd.; and "SI-110L," "SI-180L," and "SI-100L" from Sanshin Chemical Industry Co., Ltd.

[0103] Suitable sulfonic acid compounds for use as photoacid generators include, for example, alkyl sulfonic acid esters, haloalkyl sulfonic acid esters, aryl sulfonic acid esters, and iminosulfonates. Suitable specific examples of sulfonic acid compounds include benzointosylate, pyrogallol trifluoromethanesulfonate, o-nitrobenzyl trifluoromethanesulfonate, and o-nitrobenzyl p-toluenesulfonate.

[0104] Specific examples of sulfonimide compounds that can be suitably used as photoacid generators include N-(trifluoromethylsulfonyloxy)succinimide, N-(trifluoromethylsulfonyloxy)phthalimide, N-(trifluoromethylsulfonyloxy)diphenylmaleimide, N-(trifluoromethylsulfonyloxy)bicyclo[2.2.1]hept-5-ene-2,3-dicarboximide, and N-(trifluoromethylsulfonyloxy)naphthylimide.

[0105] Specific examples of diazomethane compounds that can be suitably used as photoacid generators include bis(trifluoromethylsulfonyl)diazomethane, bis(cyclohexylsulfonyl)diazomethane, and bis(phenylsulfonyl)diazomethane. Commercially available diazomethane compounds can be used.

[0106] Examples of diazoketone compounds, sulfone compounds, and diazoquinone compounds that can be suitably used as photoacid generators include those described in Japanese Patent Publication No. 2018-169627, International Publication No. 2010 / 134207, International Publication No. 2014 / 069202, Japanese Patent Publication No. 2020-101813, and International Publication No. 2018 / 232214.

[0107] As the photoradical generator, a compound capable of generating radicals upon receiving active light can be used. The photoradical generator may be used alone or in combination of two or more types.

[0108] Examples of photoradical generators include oxime ester-based photopolymerization initiators, α-aminoketone-based photopolymerization initiators, phosphine oxide-based photopolymerization initiators, α-hydroxyketone-based photopolymerization initiators, benzoin-based photopolymerization initiators, benzylketal-based photopolymerization initiators, and acylphosphine-based photopolymerization initiators.

[0109] Examples of oxime ester-based photopolymerization initiators include 2-(benzoyloxyimino)-1-[4-(phenylthio)phenyl]octan-1-one (OXE01), [1-[9-ethyl-6-(2-methylbenzoyl)carbazole-3-yl]ethylideneamino]acetate (OXE02), etanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-,1-(O-acetyloxime), and the like.

[0110] Examples of α-aminoketone-based photopolymerization initiators include 2-methyl-1-phenyl-2-morpholinopropan-1-one, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2-methyl-1-(4-hexylphenyl)-2-morpholinopropan-1-one, 2-ethyl-2-(dimethylamino)-1-(4-morpholinophenyl)butan-1-one, 2-benzyl-2-(dimethylamino)-1-(4-morpholinophenyl)butan-1-one, 2-(dimethylamino)-2-(4-methylphenylmethyl)-1-(4-morpholinophenyl)butan-1-one, and 2-methyl-1-(9,9-dibutylfluoren-2-yl)-2-morpholinopropan-1-one.

[0111] Examples of phosphine oxide-based photopolymerization initiators include bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, (2,4,6-trimethylbenzoyl)diphenylphosphine oxide, and polyoxyethylene glycerin ether tris[phenyl(2,4,6-trimethylbenzoyl)phosphine] (Polymeric TPO-L).

[0112] Examples of phosphine oxide-based photopolymerization initiators include bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, (2,4,6-trimethylbenzoyl)diphenylphosphine oxide, and polyoxyethylene glycerin ether tris[phenyl(2,4,6-trimethylbenzoyl)phosphine] (Polymeric TPO-L).

[0113] Examples of α-hydroxyketone-based photopolymerization initiators include 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenylpropanone, 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methylpropanone, and 2-hydroxy-1-{4-[4-(2-hydroxy-2-methylpropionyl)benzyl]phenyl}-2-methylpropan-1-one.

[0114] Examples of benzoin-based photopolymerization initiators include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzoin isobutyl ether. Examples of benzyl ketal-based photopolymerization initiators include 2,2-dimethoxy-2-phenylacetophenone.

[0115] Examples of acylphosphine-based photopolymerization initiators include bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide.

[0116] Commercially available photoradical generators can be used. Examples of commercially available products include "Irgacure-OXE01", "Irgacure-OXE02", "Irgacure-OXE04", and "IrgacureTPO" from BASF; "Omnirad907", "Omnirad369", "Omnirad379", "Omnirad379EG", "Omnirad819", "OmniradTPO", "Omnipol910", "OmnipolTP", and "Omnipol9210" from IGM; and "N-1919" from ADEKA.

[0117] When the photosensitive resin composition of the present invention contains a photopolymerization initiator, the content of the photopolymerization initiator in the photosensitive resin composition is, for example, 0.01% by mass or more, preferably 0.1% by mass or more, more preferably 0.5% by mass or more, even more preferably 0.85% by mass or more or 0.9% by mass or more, preferably 5% by mass or less, more preferably 4% by mass or less, and even more preferably 3% by mass or less, based on 100% by mass of the nonvolatile components in the photosensitive resin composition.

[0118] <Photosensitizer> The photosensitive resin composition of the present invention may further contain a photosensitizer as an optional component. The photosensitizer does not include organopolysiloxanes that meet the specific requirements described above, or photopolymerization initiators. Generally, photosensitizers can be excited when exposed to light, but the photosensitizer itself does not generate acids and / or radicals. In addition, when a photosensitizer is excited, it can usually transfer its energy to a photopolymerization initiator, thereby promoting the generation of acids and / or radicals. Therefore, the curing of the photosensitive resin composition can be accelerated by using a photosensitizer. One type of photosensitizer may be used alone, or two or more types may be used in combination.

[0119] Examples of photosensitizers include benzophenones such as Michla's ketone, 4,4'-bis(diethylamino)benzophenone, and 4-morpholinobenzophenone; cyclic alkanes such as 2,5-bis(4'-diethylaminobenzal)cyclopentane, 2,6-bis(4'-diethylaminobenzal)cyclohexanone, and 2,6-bis(4'-diethylaminobenzal)-4-methylcyclohexanone; chalcones such as 4,4'-bis(dimethylamino)chalcone and 4,4'-bis(diethylamino)chalcone; and p-dimethylaminocinnamyridene indano Indanones such as p-dimethylaminobenzylideneindanone; anthracenes such as 9,10-dibutoxyanthracene (DBA), 9,10-diethoxyanthracene (DEA), 9,10-dipropoxyanthracene, and 9,10-bis(2-ethylhexyloxy)anthracene; thiazoles such as 2-(p-dimethylaminophenylbiphenylene)-benzothiazole, 2-(p-dimethylaminophenylvinylene)benzothiazole, and 2-(p-dimethylaminophenylvinylene)isonaphthothiazole; 1,3-bis(4'-dimethyl Acetones such as aminobenzalacetone and 1,3-bis(4'-diethylaminobenzal)acetone; coumarins such as 3,3'-carbonyl-bis(7-diethylaminocoumarin), 3-acetyl-7-dimethylaminocoumarin, 3-ethoxycarbonyl-7-dimethylaminocoumarin, 3-benzyloxycarbonyl-7-dimethylaminocoumarin, 3-methoxycarbonyl-7-diethylaminocoumarin, and 3-ethoxycarbonyl-7-diethylaminocoumarin; N-phenyl-N'-ethylethanolamine and N-phenyldiethanolamine amines such as N-p-tolyldiethanolamine, N-phenylethanolamine, isoamyl dimethylaminobenzoate, and isoamyl diethylaminobenzoate; heterocyclic compounds such as 2-mercaptobenzimidazole, 2-mercaptobenzothiazole, 2-(p-dimethylaminostyryl)benzoxazole, 2-(p-dimethylaminostyryl)benzthiazole, 2-(p-dimethylaminostyryl)naphtho(1,2-d)thiazole, 1-phenyl-5-mercaptotetrazol, and 1-p-hydroxyphenyl-5-mercaptotetrazol;Examples include styrenes such as 2-(p-dimethylaminobenzoyl)styrene. Among these, the photosensitizer is preferably anthracene.

[0120] When the photosensitive resin composition of the present invention contains a photosensitizer, the amount of the photosensitizer in the photosensitive resin composition is, for example, 0.01% by mass or more, preferably 0.1% by mass or more, more preferably 0.15% by mass or more, even more preferably 0.2% by mass or more, preferably 10% by mass or less, more preferably 7% by mass or less, and even more preferably 5% by mass or less, based on 100% by mass of the nonvolatile components in the photosensitive resin composition.

[0121] <Silane Coupling Agent> The photosensitive resin composition of the present invention may further contain a silane coupling agent as an optional component. The silane coupling agent does not include organopolysiloxanes, photopolymerization initiators, or photosensitizers that meet the specific requirements described above. Since silane coupling agents generally contain organic reactive sites and inorganic reactive sites, they can improve the adhesion between organic materials and inorganic materials. One type of silane coupling agent may be used alone, or two or more types may be used in combination.

[0122] The silane coupling agent preferably has a structure represented by the following formula (X).

[0123]

[0124] (In formula (X), R Ｘ１ Each independently represents an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, or an acyl group having 1 to 20 carbon atoms; R Ｘ２ Each independently represents an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 10 carbon atoms; R Ｘ３ represents a monovalent organic group; n Ｘ (This represents an integer between 1 and 3.)

[0125] In equation (X), R Ｘ１ Each of these independently represents an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, or an acyl group having 1 to 20 carbon atoms.Ｘ１ Specific examples of groups represented by R include linear, branched, or cyclic alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, neopentyl, n-hexyl, n-octyl, and cyclohexyl groups; aryl groups such as phenyl, tolyl, xylyl, and naphthyl groups; and acyl groups such as formyl, acetyl, and propionyl groups. Among these, R Ｘ１ The group represented is preferably an alkyl group having 1 to 8 carbon atoms, more preferably an alkyl group having 1 to 6 carbon atoms, even more preferably a methyl group or an ethyl group, and even more preferably a methyl group.

[0126] In equation (X), R Ｘ２ Each of these independently represents an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 10 carbon atoms. Ｅ２ Specific examples of groups represented by R include linear, branched, or cyclic alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, neopentyl, n-hexyl, n-octyl, and cyclohexyl groups; and aryl groups such as phenyl, tolyl, xylyl, and naphthyl groups. Among these, R Ｘ２ The group represented is preferably an alkyl group or phenyl group having 1 to 8 carbon atoms, more preferably an alkyl group or phenyl group having 1 to 6 carbon atoms, and even more preferably a methyl group, an ethyl group, or a phenyl group.

[0127] In equation (X), R Ｘ３ R represents a monovalent organic group. Ｘ３ The monovalent organic group represented by is not particularly limited, and may contain, for example, one or more of an epoxy group, a group that reacts with an epoxy group to form a crosslinked structure, and a radical polymerizable group. The groups that react with an epoxy group to form a crosslinked structure and radical polymerizable groups are as described above. Among them, R Ｘ３ The monovalent organic group represented by preferably contains an epoxy group, and more preferably contains a glycidyl ether group.

[0128] In equation (X), n Ｘ represents an integer from 1 to 3, preferably 2 or 3, and more preferably 3.

[0129] Commercially available silane coupling agents may be used. Examples of commercially available silane coupling agents include "KBM-403" (3-glycidoxypropyltrimethoxysilane), "KBM-803" (3-mercaptopropyltrimethoxysilane), "KBE-903" (3-aminopropyltriethoxysilane), "KBM-573" (N-phenyl-3-aminopropyltrimethoxysilane), "SZ-31" (hexamethyldisilazane), "KBM-103" (phenyltrimethoxysilane), "KBM-4803" (long-chain epoxy type silane coupling agent), "KBM-7103" (3,3,3-trifluoropropyltrimethoxysilane), "LS1375" (3-mercaptopropylmethyldimethoxysilane), and "LS3610" (N-(3- Examples include: Riethoxysilylpropyl Urea; "Sira Ace S810" (3-mercaptopropyltrimethoxysilane) manufactured by Chisso Corporation; "SIM6475.0" (3-mercaptopropyltriethoxysilane), "SIM6474.0" (3-mercaptopropylmethyldimethoxysilane), "SIM6473.5C" (mercaptomethyltrimethoxysilane), "SIM6473.0" (mercaptomethylmethyldimethoxysilane), "SIU9055.0" (N-(3-triethoxysilylpropyl)urea), "SIU9058.0" (N-(3-trimethoxysilylpropyl)urea); and "VD-5" (a compound having an aminotriazine ring and an ethoxysilyl group) manufactured by Shikoku Chemicals, Inc.

[0130] When the photosensitive resin composition of the present invention contains a silane coupling agent, the content of the silane coupling agent in the photosensitive resin composition is, for example, 0.1% by mass or more, preferably 1% by mass or more, more preferably 3% by mass or more, even more preferably 4% by mass or more, preferably 10% by mass or less, more preferably 7% by mass or less, and even more preferably 5% by mass or less, based on 100% by mass of the nonvolatile components in the photosensitive resin composition.

[0131] <Other Organopolysiloxanes> The photosensitive resin composition of the present invention may further contain other organopolysiloxanes as optional components. Other organopolysiloxanes do not include organopolysiloxanes that meet the specific requirements described above, photopolymerization initiators, photosensitizers, and silane coupling agents. Other organopolysiloxanes may be used individually or in combination of two or more types.

[0132] Other organopolysiloxanes are organopolysiloxanes that do not satisfy either requirement (α) or requirement (β) above. That is, other organopolysiloxanes are organopolysiloxanes in which the siloxane structure is linear. In one embodiment, other organopolysiloxanes are organopolysiloxanes that do not contain epoxy groups.

[0133] In one embodiment, other organopolysiloxanes contain D units as a siloxane structure. The D units that other organopolysiloxanes may contain may be the same for each unit or may be different for each unit.

[0134] The terminals in the siloxane structure of other organopolysiloxanes are not particularly limited and may be M units or D units. That is, the siloxane structure of other organopolysiloxanes may have silicon atoms at the terminals or oxygen atoms at the terminals. Furthermore, for other organopolysiloxanes, the two terminals in the siloxane structure may be identical or different.

[0135] In the D unit that other organopolysiloxanes may contain, the two organic groups constituting the D unit are preferably alkyl groups having 1 to 10 carbon atoms, more preferably alkyl groups having 1 to 8 carbon atoms, even more preferably alkyl groups having 1 to 6 carbon atoms, even more preferably methyl or ethyl groups, and even more preferably methyl groups.

[0136] If the photosensitive resin composition of the present invention contains other organopolysiloxanes, the content of other organopolysiloxanes in the photosensitive resin composition is, for example, 0.1% by mass or more, preferably 1% by mass or more, more preferably 3% by mass or more, even more preferably 4% by mass or more, preferably 10% by mass or less, more preferably 7% by mass or less, and even more preferably 5% by mass or less, based on 100% by mass of the nonvolatile components in the photosensitive resin composition.

[0137] Regardless of whether the photosensitive resin composition of the present invention contains other organopolysiloxanes, the total amount of organopolysiloxanes satisfying specific requirements and other organopolysiloxanes relative to 100% by mass of the nonvolatile components in the photosensitive resin composition is preferably within a specific range. Specifically, the total amount of organopolysiloxanes satisfying both requirement (α) and requirement (β), organopolysiloxanes satisfying only requirement (α), organopolysiloxanes satisfying only requirement (β), and other organopolysiloxanes is preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, even more preferably 91% by mass or more, 92% by mass or more, or 93% by mass or more, relative to 100% by mass of the nonvolatile components in the photosensitive resin composition. The upper limit of the total amount may be 100% by mass or less (for example, 99% by mass or less, 97% by mass or less, or 95% by mass or less). When the total amount falls within the above range, it is preferable because it easily results in a photosensitive resin composition that provides an optical waveguide with excellent processability.

[0138] <Epoxy Resin> The photosensitive resin composition of the present invention may or may not further contain an epoxy resin as an optional component. The epoxy resin as an optional component does not include organopolysiloxanes that satisfy the specific requirements described above, photopolymerization initiators, photosensitizers, silane coupling agents, and other organopolysiloxanes. One type of epoxy resin may be used alone, or two or more types may be used in combination.

[0139] As mentioned above, epoxy resin does not fall under either the organopolysiloxanes that meet the specific requirements described above, or other organopolysiloxanes. Therefore, other epoxy resins are components that contain epoxy groups but do not contain siloxane bonds.

[0140] The epoxy resin is not particularly limited as long as it is a curable resin containing one or more (preferably two or more) epoxy groups per molecule. The epoxy resin may be, for example, an epoxy resin containing an aromatic ring, or a hydrogenated epoxy resin obtained by hydrogenating the epoxy resin containing the aromatic ring to form an alicyclic structure. In particular, the epoxy resin preferably contains a hydrogenated epoxy resin, and more preferably is a hydrogenated epoxy resin.

[0141] The epoxy group equivalent of the epoxy resin is preferably 50 g / eq. to 2000 g / eq., more preferably 60 g / eq. to 1000 g / eq., and even more preferably 80 g / eq. to 500 g / eq. The epoxy group equivalent is the mass of the epoxy resin containing one equivalent of epoxy groups and can be measured according to JIS K7236.

[0142] The molecular weight of the epoxy resin (if it has a molecular weight distribution, the weight-average molecular weight (Mw) is used instead of the molecular weight) is preferably 100 to 5,000, more preferably 250 to 3,000, and even more preferably 400 to 1,500.

[0143] As described above, the photosensitive resin composition of the present invention may or may not contain epoxy resin. In particular, the epoxy resin content is preferably less than 10% by mass, more preferably less than 7% by mass, more preferably less than 5% by mass, more preferably less than 3% by mass, and even more preferably less than 1% by mass, relative to 100% by mass of the nonvolatile components in the photosensitive resin composition, from the viewpoint of reducing the refractive index of the cured product of the photosensitive resin composition (furthermore, making the refractive index of the cured product of the photosensitive resin composition at a wavelength of 1310 nm preferably less than 1.5, more preferably 1.495 or less, and even more preferably 1.492 or less). The lower limit of the epoxy resin content may be 0% by mass or greater than 0% by mass, but it is more preferable as it approaches 0% by mass, and preferably 0% by mass. When the epoxy resin content is within the above range, it is preferable because it is easy to obtain a photosensitive resin composition that provides an optical waveguide with excellent processability and low optical transmission loss.

[0144] Similarly, the photosensitive resin composition of the present invention may or may not contain a hydrogenated epoxy resin. In particular, the content of the hydrogenated epoxy resin is preferably less than 5% by mass, more preferably less than 3% by mass, more preferably less than 1% by mass, more preferably less than 0.5% by mass, and even more preferably less than 0.1% by mass, relative to 100% by mass of the nonvolatile components in the photosensitive resin composition, from the viewpoint of reducing the refractive index of the cured product of the photosensitive resin composition (furthermore, making the refractive index of the cured product of the photosensitive resin composition at a wavelength of 1310 nm preferably less than 1.5, more preferably 1.495 or less, and even more preferably 1.492 or less). The lower limit of the content of the hydrogenated epoxy resin may be 0% by mass or greater than 0% by mass, but it is more preferable as it approaches 0% by mass, and is preferably 0% by mass. When the content of the hydrogenated epoxy resin is within the above range, it is preferable because it is easy to obtain a photosensitive resin composition that provides an optical waveguide with excellent processability and low optical transmission loss.

[0145] <Organic Solvents> The photosensitive resin composition of the present invention may further contain an organic solvent as an optional component. The organic solvent does not include organopolysiloxanes, photopolymerization initiators, photosensitizers, silane coupling agents, other organopolysiloxanes, or epoxy resins that meet the specific requirements described above. One type of organic solvent may be used alone, or two or more types may be used in combination.

[0146] Examples of organic solvents include ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ester solvents such as methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, isoamyl acetate, methyl propionate, ethyl propionate, and γ-butyrolactone; ether solvents such as tetrahydropyran, tetrahydrofuran, 1,4-dioxane, diethyl ether, diisopropyl ether, dibutyl ether, diphenyl ether, and anisole; alcohol solvents such as methanol, ethanol, propanol, butanol, and ethylene glycol; and 2-ethoxyethyl acetate, propylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl diglycol acetate, γ-butyrolactone, and methyl methoxypropionate. Examples of solvents include ether ester solvents such as methyl lactate, ethyl lactate, and methyl 2-hydroxyisobutyrate; ether alcohol solvents such as 2-methoxypropanol, 2-methoxyethanol, 2-ethoxyethanol, propylene glycol monomethyl ether, and diethylene glycol monobutyl ether (butyl carbitol); amide solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone; sulfoxide solvents such as dimethyl sulfoxide; nitrile solvents such as acetonitrile and propionitrile; aliphatic hydrocarbon solvents such as hexane, cyclopentane, cyclohexane, and methylcyclohexane; and aromatic hydrocarbon solvents such as benzene, toluene, xylene, ethylbenzene, and trimethylbenzene.

[0147] When the photosensitive resin composition of the present invention contains an organic solvent, the content of the organic solvent in the photosensitive resin composition is preferably 50% by mass or less, more preferably 30% by mass or less, and even more preferably 20% by mass or less, based on 100% by mass of all components in the photosensitive resin composition. The lower limit of such organic solvent content may be 0% by mass or greater than 0% by mass.

[0148] <Other Additives> The photosensitive resin composition of the present invention may further contain other additives as optional components. Other additives do not include organopolysiloxanes that meet the specific requirements described above, photopolymerization initiators, photosensitizers, silane coupling agents, other organopolysiloxanes, epoxy resins, and organic solvents. Other additives may be used individually or in combination of two or more types.

[0149] Other additives include, for example, thermosetting resins such as active ester resins, phenol resins, naphthol resins, carbodiimide resins, acid anhydride resins, cyanate ester resins, and amine resins; adhesion promoters; surfactants such as fluorine-based surfactants, nonionic surfactants, cationic surfactants, anionic surfactants, and silicone-based surfactants; thermoplastic resins; colorants such as phthalocyanine blue, phthalocyanine green, iodine green, diazo yellow, crystal violet, titanium dioxide, carbon black, and naphthalene black; hydroquinone, phenothiazine, methylhydroquinone, and hydroquinone monomer. Examples of additives include polymerization inhibitors such as thyryl ether, catechol, and pyrogallol; thickeners such as bentonite and montmorillonite; silicone-based, fluorine-based, and vinyl resin-based defoaming agents; flame retardants such as phosphorus-based flame retardants (e.g., phosphate ester compounds, phosphazene compounds, phosphinic acid compounds, red phosphorus), nitrogen-based flame retardants (e.g., melamine sulfate), halogen-based flame retardants, and inorganic flame retardants (e.g., antimony trioxide); ultraviolet absorbers such as benzotriazole-based ultraviolet absorbers; and stabilizers such as borate-based stabilizers, titanate-based stabilizers, aluminate-based stabilizers, zirconate-based stabilizers, isocyanate-based stabilizers, carboxylic acid-based stabilizers, and carboxylic acid anhydride-based stabilizers. When the photosensitive resin composition of the present invention contains other additives, the content of the other additives in the photosensitive resin composition may be determined according to the properties required of the photosensitive resin composition. Furthermore, the organopolysiloxanes, photopolymerization initiators, photosensitizers, silane coupling agents, other organopolysiloxanes, epoxy resins, and organic solvents that meet the specific requirements described above may also have functions such as thermosetting resins, adhesion promoters, surfactants, thermoplastic resins, colorants, polymerization inhibitors, thickeners, defoamers, flame retardants, ultraviolet absorbers, and stabilizers. In such cases, such components shall be considered not as other additives, but as components of the organopolysiloxanes, photopolymerization initiators, photosensitizers, silane coupling agents, other organopolysiloxanes, epoxy resins, and organic solvents that meet the specific requirements described above.

[0150] [Method for Manufacturing the Photosensitive Resin Composition] The photosensitive resin composition of the present invention can be manufactured, for example, by mixing the components that may be included in the photosensitive resin composition. In one embodiment, the photosensitive resin composition of the present invention can be manufactured by a manufacturing method comprising the step of mixing an organopolysiloxane that satisfies both requirement (α) and requirement (β) with an arbitrary component. In another embodiment, the photosensitive resin composition of the present invention can be manufactured by a manufacturing method comprising the step of mixing an organopolysiloxane that satisfies only requirement (α), an organopolysiloxane that satisfies only requirement (β), and an arbitrary component. In yet another embodiment, the photosensitive resin composition of the present invention can be manufactured by a manufacturing method comprising the step of mixing an organopolysiloxane that satisfies both requirement (α) and requirement (β), an organopolysiloxane that satisfies only requirement (α) and / or an organopolysiloxane that satisfies only requirement (β), and an arbitrary component. In these manufacturing methods, optional components include the photopolymerization initiators, photosensitizers, silane coupling agents, other organopolysiloxanes, epoxy resins, organic solvents, and other additives mentioned above. In these manufacturing methods, some or all of the components may be mixed simultaneously, or they may be mixed sequentially. Furthermore, these manufacturing methods may optionally include kneading or stirring (mixing) the photosensitive resin composition using kneading means such as a three-roll mill, ball mill, bead mill, or sand mill, or stirring means such as a super mixer, planetary mixer, or high-speed rotary mixer.

[0151] [Characteristics of the Photosensitive Resin Composition] The photosensitive resin composition of the present invention contains an organopolysiloxane that satisfies the specific requirements described above (and optionally contains a photopolymerization initiator, a photosensitizer, a silane coupling agent, other organopolysiloxanes, epoxy resins, organic solvents, and other additives), making it possible to manufacture optical waveguides with excellent processability.

[0152] According to the photosensitive resin composition of the present invention, an optical waveguide excellent in processability can be manufactured. For example, when observing the end face of the optical waveguide cut according to the method described in <Test Example 3; Evaluation of Processability of Optical Waveguide> described later, the end face of the optical waveguide does not collapse and remains clean.

[0153] According to the photosensitive resin composition of the present invention, an optical waveguide with low Fresnel loss can be manufactured when connected to an optical fiber. Therefore, when an optical fiber and an optical waveguide manufactured using the photosensitive resin composition of the present invention are connected, the amount of light that is Fresnel reflected in the light entering from the optical fiber into the core layer of the optical waveguide can be reduced. For example, when light enters from an object with a refractive index of n １ to an object with a refractive index of n ２ , the Fresnel reflectance T of the perpendicularly incident light can be calculated by the following formula (1). T = { (n １ - n ２ ) ÷ (n １ + n ２ )} ２ ... (1) Here, when the refractive index of the optical fiber is 1.468 and the refractive index of the core layer of the optical waveguide is n ｃｏｒｅ , the above formula (1) can be rewritten as the following formula (1'). T = { (n ｃｏｒｅ - 1.468) ÷ (n ｃｏｒｅ + 1.468)} ２ ... (1') By using the Fresnel reflectance T obtained by the above formula (1) or formula (1'), the value L of the Fresnel loss when light perpendicularly enters from the optical fiber into the core layer of the optical waveguide can be calculated from the following formula (2). L = (-10) × log １０ (1 - T)... (2) The value L of the Fresnel loss when light perpendicularly enters from the optical fiber into the core layer of the optical waveguide is preferably 0.001 dB or less (1 × 10 －３ dB or less), more preferably 0.0008 dB or less (8 × 10 －４ dB or less), and even more preferably 0.0006 dB or less (6 × 10 －４ dB or less). The lower limit of the value L of the Fresnel loss can be, for example, 0.0000001 dB or more (1 × 10 －７ dB or more), etc.

[0154] The photosensitive resin composition of the present invention can produce optical waveguides with low Fresnel loss when connected to optical fibers, and therefore the cured product of the photosensitive resin composition of the present invention may have a refractive index within a specific range. The refractive index of the cured product of the photosensitive resin composition at a wavelength of 1310 nm is preferably less than 1.5, more preferably 1.495 or less, even more preferably 1.492 or less, preferably 1.445 or more, more preferably 1.45 or more, and even more preferably 1.453 or more.

[0155] Regarding the measurement of the refractive index of the cured product of the photosensitive resin composition, the refractive index of the cured product at a wavelength of 1310 nm can be measured by the methods described in (2-1) to (2-5) below. (2-1): If each photosensitive resin composition contains a photopolymerization initiator, the photosensitive resin composition is subjected to step (2-2). If each photosensitive resin composition does not contain a photopolymerization initiator, 0.1% by mass of a photopolymerization initiator is added to 100% by mass of the nonvolatile components of the photosensitive resin composition, and the composition is subjected to step (2-2). (2-2): The photosensitive resin composition (or, if necessary, a resin varnish obtained by dissolving the photosensitive resin composition in an organic solvent) is applied to the flat surface of a member having a flat surface, such as a silicon wafer, to obtain a resin composition layer with a thickness of 10 μm. (2-3): The formed resin composition layer is subjected to a wavelength of 365 nm and an illuminance of 35 mW / cm². ２ and 5J / cm ２ Exposure treatment is performed under the following conditions. (2-4): The resin composition layer after exposure is subjected to a heat treatment at 190°C for 90 minutes in an atmospheric environment to cure the resin composition layer. (2-5): The cured resin composition layer obtained is measured at a measurement wavelength of 1310 nm, room temperature (25°C), and atmospheric pressure (1 atm). Note that if various conditions such as the type and amount of photopolymerization initiator, (if necessary, the amount of organic solvent used when preparing the resin varnish), the wavelength and amount of light in the exposure treatment, and the heating temperature and heating time in the heat treatment after exposure are changed, the coefficient of variation of the refractive index due to such changes in conditions is 0.5% or less.

[0156] The photopolymerization initiator used in step (2-1) above can be appropriately selected depending on the type of components contained in the photosensitive resin composition. For example, the components described in the section on <Photopolymerization Initiators> above can be used as photopolymerization initiators.

[0157] The photosensitive resin composition of the present invention makes it possible to manufacture optical waveguides with low optical transmission loss. For example, when the optical transmission loss of an optical waveguide manufactured using the photosensitive resin composition is measured according to the method described in the section "Test Example 2; Measurement of Optical Transmission Loss" below, the value of the optical transmission loss is preferably 1.5 dB / cm or less, more preferably 1.2 dB / cm or less, even more preferably 1 dB / cm or less, even more preferably 0.8 dB / cm or less, and still more preferably 0.7 dB / cm or less. The lower limit of the value of the optical transmission loss can be, for example, 0.0001 dB / cm or more.

[0158] The photosensitive resin composition of the present invention makes it possible to manufacture optical waveguides with excellent patternability. Therefore, the photosensitive resin composition of the present invention makes it possible to form the core layer of an optical waveguide with a smaller exposure dose. Furthermore, the photosensitive resin composition of the present invention makes it possible to advantageously form trenches or holes in an optical waveguide having trenches or holes by combining selective exposure and development processes with a smaller exposure dose. For example, the exposure dose at which the core layer does not disappear during spray development is compared according to the method described in the section "Test Example 5: Evaluation of Patternability of Optical Waveguides" below. The exposure dose at which the core layer does not disappear during spray development is 8 J / cm². ２ Preferably, it is 2 J / cm ２ It is more preferable that the following is the case: 0.2 J / cm² ２ The following is even more preferable:

[0159] The photosensitive resin composition of the present invention makes it possible to manufacture optical waveguides with excellent substrate adhesion. For example, as described in the section "Test Example 6: Evaluation of Substrate Adhesion of Optical Waveguides" below, in the silicon wafer as a substrate and the cladding layer of the optical waveguide, lattice-shaped cuts are made at 1 mm intervals in accordance with JIS K 5600-5-6 to form 10 cured pieces in the vertical direction and 10 in the horizontal direction, for a total of 100 pieces. Here, the fewer the number of cured pieces that peel off from the silicon wafer, the better the substrate adhesion of the optical waveguide is. When the 100 formed cured pieces are observed, the number of cured pieces that peel off from the silicon wafer is preferably less than 50, and more preferably 0.

[0160] [Uses of the Photosensitive Resin Composition] The photosensitive resin composition of the present invention can be used as a photosensitive resin composition for manufacturing optical waveguides. More specifically, the photosensitive resin composition of the present invention can be suitably used as a core resin composition for forming the core layer of an optical waveguide, and can also be suitably used as a cladding resin composition for forming the cladding layer of an optical waveguide. When manufacturing an optical waveguide, the photosensitive resin composition of the present invention may be used in the form of a photosensitive resin composition set described later. Therefore, in one embodiment, the present invention also provides a core resin composition containing the photosensitive resin composition of the present invention. Furthermore, in one embodiment, the present invention also provides a cladding resin composition containing the photosensitive resin composition of the present invention. Furthermore, the present invention also provides a photosensitive resin composition set containing a core resin composition according to one embodiment of the present invention and a cladding resin composition according to one embodiment of the present invention. The photosensitive resin composition set according to one embodiment of the present invention will be described in detail below, and preferred embodiments of the core resin composition according to one embodiment of the present invention and preferred embodiments of the cladding resin composition according to one embodiment of the present invention will be shown.

[0161] [Photosensitive Resin Composition Set] A photosensitive resin composition set according to one embodiment of the present invention includes a core resin composition and a cladding resin composition. The core resin composition includes the photosensitive resin composition of the present invention, preferably only the photosensitive resin composition of the present invention. The cladding resin composition includes the photosensitive resin composition of the present invention, preferably only the photosensitive resin composition of the present invention. The core resin composition can be suitably used as a resin composition for forming the core layer of an optical waveguide, and the cladding resin composition can be suitably used as a resin composition for forming the cladding layer of an optical waveguide. The photosensitive resin composition set can be used in the manufacture of an optical waveguide comprising a core layer containing a cured product of the core resin composition and a cladding layer containing a cured product of the cladding resin composition.

[0162] As described above, the photosensitive resin composition set can be used as a photosensitive resin composition for manufacturing optical waveguides. The photosensitive resin composition set is preferably used for forming optical waveguides capable of transmitting light with wavelengths of 1300 nm to 1320 nm, and is also preferably used for forming single-mode optical waveguides. In a more preferred embodiment, the photosensitive resin composition set can be used for forming single-mode optical waveguides for light with a wavelength of 1310 nm.

[0163] The core resin composition contains an organopolysiloxane that satisfies the specific requirements described above. Preferably, the core resin composition further contains an organic solvent in addition to the organopolysiloxane that satisfies the specific requirements described above. According to embodiments that further contain an organic solvent, the viscosity of the core resin composition can be further reduced, thereby allowing for a smaller width and / or thickness of the core layer of the optical waveguide. Therefore, a core resin composition further containing an organic solvent can significantly contribute to realizing a single-mode optical waveguide (and consequently, increasing the design flexibility of the package when the optical waveguide is applied to a semiconductor package).

[0164] Furthermore, the cladding resin composition contains an organopolysiloxane that satisfies the specific requirements described above. Preferably, the cladding resin composition further contains a silane coupling agent in addition to the organopolysiloxane that satisfies the specific requirements described above. According to embodiments that further contain a silane coupling agent, the adhesion between the substrate and the cladding layer (first cladding layer) can be improved during the manufacture of the optical waveguide. Therefore, a cladding resin composition further containing a silane coupling agent can significantly contribute to improving the reliability in the manufacture of optical waveguides.

[0165] In one or both of the core resin composition and the cladding resin composition, it is preferable that the organopolysiloxane satisfying one or both of requirements (α) and (β) does not contain radical polymerizable groups in its molecule. The embodiment in which the organopolysiloxane satisfying one or both of requirements (α) and (β) does not contain radical polymerizable groups in its molecule is preferable because it can provide an optical waveguide with excellent processability while also providing an optical waveguide with excellent patternability.

[0166] In one or both of the core resin composition and the cladding resin composition, it is preferable that the organopolysiloxane satisfying one or both of requirements (α) and (β) does not contain an aromatic ring in its molecule. An embodiment in which the organopolysiloxane satisfying one or both of requirements (α) and (β) does not contain an aromatic ring is preferable because it can provide an optical waveguide with excellent processability while also providing an optical waveguide with low optical transmission loss.

[0167] In one or both of the core resin composition and the cladding resin composition, the organopolysiloxane that satisfies one or both of requirements (α) and (β) preferably does not contain a fluorine atom in its molecule (i.e., contains only non-skeletal atoms selected from the group consisting of hydrogen atoms and halogen atoms other than fluorine atoms as non-skeletal atoms), and more preferably contains only hydrogen atoms as non-skeletal atoms (i.e., does not contain halogen atoms as non-skeletal atoms). The embodiment in which the organopolysiloxane that satisfies one or both of requirements (α) and (β) does not contain a fluorine atom is preferable because, compared to the embodiment containing a fluorine atom, it can provide an optical waveguide with excellent processability while also providing an optical waveguide with excellent substrate adhesion.

[0168] In a resin composition for cladding, the organopolysiloxane satisfying requirement (α) preferably contains a cyclic siloxane structure, and more preferably contains a cyclic siloxane structure containing only D units. The embodiment in which the organopolysiloxane satisfying requirement (α) contains a cyclic siloxane structure, and furthermore contains a cyclic siloxane structure containing only D units, is preferable because it can reduce the stress that may occur when cutting the optical waveguide, resulting in an optical waveguide with particularly excellent machinability and excellent patternability, compared to the embodiment without a cyclic siloxane structure and the embodiment containing a cyclic siloxane structure containing at least one of T units and Q units.

[0169] As mentioned above, the photosensitive resin composition of the present invention can produce optical waveguides with low Fresnel loss when connected to optical fibers, and therefore the cured product of the core resin composition may have a refractive index within a specific range. The refractive index of the cured product of the core resin composition at a wavelength of 1310 nm is preferably less than 1.5, more preferably 1.495 or less, even more preferably 1.493 or less or 1.492 or less, preferably 1.45 or more, more preferably 1.455 or more, and even more preferably 1.459 or more or 1.46 or more.

[0170] As described above, since the cured product of the core resin composition may have a refractive index within a specific range, the cured product of the cladding resin composition may also have a refractive index within a specific range. The refractive index of the cured product of the cladding resin composition at a wavelength of 1310 nm is preferably 1.43 or higher, more preferably 1.44 or higher. Even more preferably 1.45 or higher, preferably 1.495 or lower, more preferably 1.49 or lower, and even more preferably 1.487 or lower or 1.486 or lower.

[0171] [Optical waveguide and method for manufacturing the same] An optical waveguide can be manufactured using the photosensitive resin composition set described above. The present invention also provides such an optical waveguide. Hereinafter, embodiments of the optical waveguide will be described with reference to the drawings.

[0172] Figure 1 is a schematic perspective view showing an optical waveguide 10 according to one embodiment of the present invention. As shown in Figure 1, the optical waveguide 10 comprises a core layer 100 and a cladding layer 200. The core layer 100 and the cladding layer 200 contain a cured product of the photosensitive resin composition of the present invention, and preferably contain only a cured product of the photosensitive resin composition of the present invention.

[0173] The core layer 100 is provided within the cladding layer 200. Therefore, the core layer 100 is covered by the cladding layer 200. In one example, the entire circumferential surface of the core layer 100 is covered by the cladding layer 200. The core layer 100 and the cladding layer 200 are in direct contact without any other layers in between, and therefore, an interface 100I can be formed between the core layer 100 and the cladding layer 200. Since the core layer 100 has a higher refractive index than the cladding layer 200, light (not shown) can be transmitted through the core layer 100 from one end (incident end) 100A to the other end (exit end) 100B.

[0174] The wavelengths of light that the optical waveguide 10 can transmit can be selected from a variety of options. For example, preferred wavelength ranges for the transmitted light may be 840 nm to 860 nm (e.g., 850 nm), 1300 nm to 1320 nm (e.g., 1310 nm), 1540 nm to 1560 nm (e.g., 1550 nm), etc. Among these, the preferred wavelength range for the light transmitted through the optical transmission path 10 is 1300 nm to 1320 nm.

[0175] The optical waveguide 10 may be a single-mode optical waveguide or a multi-mode optical waveguide, but it is preferable that it be a single-mode optical waveguide. In particular, it is preferable that the optical waveguide 10 is a single-mode optical waveguide for light in the above preferred wavelength range. For example, it is preferable that the optical waveguide 10 is a single-mode optical waveguide for light with a wavelength of 1310 nm.

[0176] The width L of the core layer 100 is preferably set appropriately within a range that allows light transmission. Specifically, the range of the width L of the core layer 100 is preferably 0.5 μm or more, more preferably 1 μm or more, even more preferably 2 μm or more, preferably 30 μm or less, more preferably 20 μm or less, and even more preferably 10 μm or less or 5 μm or less. The width L of the core layer 100 corresponds to the line width (line) of the core layer 100 when viewed from the thickness direction.

[0177] The spacing S of the core layers 100 should preferably be set appropriately within a range that allows light transmission. Specifically, the range of the spacing S of the core layers 100 is preferably 50 μm or more, more preferably 70 μm or more, even more preferably 100 μm or more, preferably 1000 μm or less, more preferably 700 μm or less, and even more preferably 500 μm or less. The spacing S of the core layers 100 corresponds to the spacing (space) of the core layers as viewed from the thickness direction.

[0178] The thickness T of the core layer 100 is preferably set appropriately within a range that allows light transmission. Specifically, the range of the thickness T of the core layer 100 is preferably 0.5 μm or more, more preferably 1 μm or more, even more preferably 2 μm or more, preferably 50 μm or less, more preferably 30 μm or less, even more preferably 20 μm or less, 15 μm or less, 10 μm or less, or 5 μm or less.

[0179] The thickness of the cladding layer 200 is greater than the thickness T of the core layer 100. The specific thickness of the cladding layer 200 is preferably 5 μm or more, more preferably 7 μm or more, even more preferably 10 μm or more, preferably 100 μm or less, more preferably 60 μm or less, and even more preferably 40 μm or less or 30 μm or less.

[0180] The optical waveguide 10 may include any elements other than the core layer 100 and the cladding layer 200, as needed. Examples of optional elements include a protective layer (not shown) to protect the core layer 100 and the cladding layer 200, a wiring layer such as a plating layer (not shown), trenches or holes (not shown) for forming the wiring layer, and a substrate 300. In an optical waveguide 10 with a substrate 300, the cladding layer 200 is usually provided on the substrate 300, and the core layer 100 is provided within the cladding layer 200.

[0181] As the substrate 300, a hard substrate such as a glass substrate, metal substrate, ceramic substrate, wafer, or circuit board may be used. As the wafer, for example, a semiconductor wafer such as a silicon wafer, gallium arsenide (GaAs) wafer, indium phosphide (InP) wafer, gallium phosphide (GaP) wafer, gallium nitride (GaN) wafer, gallium tellurium (GaTe) wafer, zinc selenium (ZnSe) wafer, or silicon carbide (SiC) wafer may be used, or a pseudo-wafer may be used. As a pseudo-wafer, for example, a plate-shaped member comprising a mold resin and electronic components embedded in the mold resin may be used. As the circuit board, for example, a glass epoxy substrate, metal substrate, polyester substrate, polyimide substrate, BT resin substrate, thermosetting polyphenylene ether substrate, etc. Here, a circuit board refers to a substrate on which a conductive layer (circuit) with a pattern is formed on one or both sides of the above substrate. Furthermore, the substrate 300 may be a film made of a plastic material such as polyethylene terephthalate, polyimide, or polyester. Additionally, a flexible circuit board may be used as the substrate 300.

[0182] The optical waveguide 10 can be manufactured using the photosensitive resin composition set described above. For example, the optical waveguide 10 can be manufactured by a method that includes, in this order: (1) forming a first resin composition layer containing a cladding resin composition; (2) curing the first resin composition layer; (3) forming a second resin composition layer containing a core resin composition on the first resin composition layer; (4) exposing the second resin composition layer; (5) developing the second resin composition layer; (6) curing the second resin composition layer; (7) forming a third resin composition layer containing a cladding resin composition on the second resin composition layer; and (8) curing the third resin composition layer. As mentioned above, the photosensitive resin composition set includes the photosensitive resin composition of the present invention as the core resin composition and the cladding resin composition. Therefore, in the method for manufacturing the optical waveguide 10, the core resin composition and the cladding resin composition include the photosensitive resin composition of the present invention. The method for manufacturing the optical waveguide 10 may, if necessary, include a step (step (9)) of forming a conductor layer as a wiring layer after the completion of step (8).

[0183] <Step (1)> A method for manufacturing an optical waveguide according to one embodiment of the present invention includes step (1) of forming a first resin composition layer containing a cladding resin composition.

[0184] Figure 2 is a schematic cross-sectional view illustrating step (1) of a method for manufacturing an optical waveguide according to one embodiment of the present invention. In this embodiment, as shown in Figure 2, an example of forming a first resin composition layer 210 on a substrate 300 will be described.

[0185] There are no particular restrictions on the method for forming the first resin composition layer 210. For example, the first resin composition layer 210 may be formed by applying a cladding resin composition onto the substrate 300.

[0186] Examples of coating methods include gravure coating, microgravure coating, reverse coating, kiss reverse coating, die coating, slot die coating, lip coating, comma coating, blade coating, roll coating, knife coating, curtain coating, chamber gravure coating, slot orifice coating, spin coating, slit coating, spray coating, dip coating, hot melt coating, bar coating, applicator coating, air knife coating, curtain flow coating, offset printing, brush coating, and screen printing.

[0187] The cladding resin composition may be applied in a single application or in multiple applications. Alternatively, different application methods may be combined. To avoid contamination, application is preferably carried out in an environment with minimal foreign matter generation, such as a cleanroom.

[0188] After applying the cladding resin composition, the first resin composition layer 210 may be dried as needed. Drying can be performed using a drying device such as a hot air furnace or a far-infrared furnace. The drying conditions are preferably set appropriately according to the composition of the cladding resin composition. Specifically, the drying temperature is preferably 50°C or higher, more preferably 70°C or higher, even more preferably 80°C or higher, preferably 150°C or lower, more preferably 130°C or lower, and even more preferably 120°C or lower. The drying time is preferably 30 seconds or more, more preferably 60 seconds or more, even more preferably 120 seconds or more, preferably 60 minutes or less, more preferably 20 minutes or less, and even more preferably 5 minutes or less.

[0189] The first resin composition layer 210 formed on the substrate 300 in step (1) contains a cladding resin composition, preferably containing only a cladding resin composition.

[0190] In step (1), the first resin composition layer 210 formed on the substrate 300 preferably further contains a silane coupling agent in addition to an organopolysiloxane that satisfies the above-mentioned specific requirements. According to the embodiment in which the first resin composition layer 210 contains a silane coupling agent, the adhesion between the substrate 300 and the cured first resin composition layer 220 can be improved.

[0191] <Step (2)> A method for manufacturing an optical waveguide according to one embodiment of the present invention includes step (2) of curing the first resin composition layer after step (1). Step (2) may be, for example, heat treatment of the first resin composition layer 210. The heat treatment conditions may be selected according to the composition of the cladding resin composition, preferably in the range of 150°C to 250°C for 20 minutes to 180 minutes, and more preferably in the range of 160°C to 230°C for 30 minutes to 120 minutes. The atmosphere for the heat treatment may be in air or in an inert gas atmosphere such as nitrogen. Among these, an inert gas atmosphere such as nitrogen is preferred for the heat treatment.

[0192] Furthermore, the first resin composition layer 210 may be cured by exposure treatment. It is preferable to use an appropriate active light for the exposure treatment, depending on the composition of the cladding resin composition. The wavelength of the active light is, for example, 190 nm to 1000 nm, preferably 240 nm to 550 nm, but other wavelengths of light may also be used. Specific examples of active light sources include ultraviolet light, visible light, electron beams, X-rays, etc., with ultraviolet light being preferred. The exposure dose is preferably in the range of 10 mJ / cm². ２ More preferably 50 mJ / cm² ２ More preferably 200 mJ / cm ２ The above is true, and preferably 10,000 mJ / cm². ２ More preferably, 8,000 mJ / cm² ２ More preferably, 4,000 mJ / cm² ２ Below, 3,000mJ / cm ２ Below, 2,000mJ / cm ２ The following or 1,000 mJ / cm ２The following applies. Furthermore, the first resin composition layer 210 may be cured by combining exposure treatment and heat treatment.

[0193] Figure 3 is a schematic cross-sectional view illustrating step (2) of a method for manufacturing an optical waveguide according to one embodiment of the present invention. By curing the first resin composition layer 210 in step (2), a cured first resin composition layer 220 is obtained on the substrate 300, as shown in Figure 3. This cured first resin composition layer 220 forms a part of the cladding layer 200 and may hereinafter be referred to as the "first cladding layer" 220.

[0194] <Step (3)> A method for manufacturing an optical waveguide according to one embodiment of the present invention includes, after step (2), step (3) of forming a second resin composition layer containing a core resin composition on a first resin composition layer.

[0195] Figure 4 is a schematic cross-sectional view illustrating step (3) of a method for manufacturing an optical waveguide according to one embodiment of the present invention. In step (3), as shown in Figure 4, a second resin composition layer 110 containing a core resin composition is formed on a first cladding layer 220, which is a cured first resin composition layer.

[0196] There are no particular restrictions on the method for forming the second resin composition layer 110. For example, the second resin composition layer 110 may be formed by applying the core resin composition onto the first cladding layer 220. The application of the core resin composition in step (3) can be carried out in the same manner as the application of the cladding resin composition in step (1). After the application of the core resin composition, the second resin composition layer 110 may be dried as needed. The drying of the second resin composition layer 110 can be carried out using the same method and conditions as the drying of the first resin composition layer 210.

[0197] In step (3), the second resin composition layer 110 formed on the first cladding layer 220 contains the core resin composition, preferably containing only the core resin composition.

[0198] In step (3), the second resin composition layer 110 formed on the first cladding layer 220 preferably further contains an organic solvent in addition to the organopolysiloxane that satisfies the specific requirements described above. According to the embodiment in which the second resin composition layer 110 contains an organic solvent, the width L and / or thickness T of the core layer 100 of the optical waveguide can be made smaller.

[0199] <Step (4)> A method for manufacturing an optical waveguide according to one embodiment of the present invention includes step (4), in which a second resin composition layer is subjected to exposure treatment after step (3).

[0200] Figure 5 is a schematic cross-sectional view illustrating step (4) of a method for manufacturing an optical waveguide according to one embodiment of the present invention. In step (4), as shown in Figure 5, a latent image is formed in the second resin composition layer 110 by selective exposure treatment. Specifically, in the exposure treatment, light P is selectively irradiated onto a specific portion of the second resin composition layer 110. Therefore, after exposure treatment, the second resin composition layer 110 is provided with an exposed portion 111 that has been irradiated with light and an unexposed portion 112 that has not been irradiated with light. Normally, the core resin composition functions as a negative-type photosensitive resin composition, so a latent image corresponding to the core layer is formed by the exposed portion 111.

[0201] From the viewpoint of selective exposure, the exposure process in step (4) is usually performed using a mask 400. Specifically, in this exposure process, light P is irradiated onto the second resin composition layer 110 through a mask 400 having a light-transmitting portion 410 and a light-shielding portion 420. The light P passes through the light-transmitting portion 410 and enters the exposure portion 111, but cannot pass through the light-shielding portion 420 and therefore cannot enter the non-exposure portion 112. Thus, the exposure portion 111 and the non-exposure portion 112 corresponding to the light-transmitting portion 410 and the light-shielding portion 420 can be provided in the second resin composition layer 110. The mask 400 may be in close contact with the second resin composition layer 110 as shown in Figure 5 (contact exposure method), or exposure may be performed using parallel light rays without contact (non-contact exposure method).

[0202] Generally, the light-transmitting portion 410 of the mask 400 is formed to have a planar shape corresponding to the core layer of the optical waveguide. Therefore, the light-shielding portion 420 of the mask 400 is formed to have a planar shape corresponding to the portion of the optical waveguide that does not have a core layer. Unless otherwise specified, "planar shape" refers to the shape as viewed from the thickness direction. The light-transmitting portion 410 formed to have a planar shape corresponding to the core layer may hereafter be referred to as the "mask pattern".

[0203] The light P used in the exposure treatment in step (IV) may be an active light ray within the same range as the exposure treatment for the first resin composition layer 210 in step (2). The exposure amount of light P is preferably set so that a desired core layer can be formed after curing in step (7). In one example, the specific range of exposure amounts in step (4) may be the same range as the exposure amount for the first resin composition layer 210 in step (2).

[0204] Since the core resin composition functions as a negative-type photosensitive resin composition, its solubility in the developer decreases in the exposed area 111. On the other hand, its solubility in the developer is high in the unexposed area 112. This difference in solubility between the exposed area 111 and the unexposed area 112 is utilized to perform the development process in the subsequent step (5).

[0205] A method for manufacturing an optical waveguide according to one embodiment of the present invention may include a step (X) after step (4) and before step (5) in which the second resin composition layer 110 is preheated, from the viewpoint of curing the second resin composition layer 110. Step (X) can quickly reduce the solubility of the exposure portion 111 in the developer. The heating in step (X) may be performed using a hot plate or an oven. The heating temperature may be, for example, 40°C to 110°C. The heating time may be, for example, 30 seconds to 60 minutes.

[0206] <Step (5)> A method for manufacturing an optical waveguide according to one embodiment of the present invention includes step (5), after step (4), a developing treatment applied to the second resin composition layer.

[0207] Figure 6 is a schematic cross-sectional view illustrating step (5) of a method for manufacturing an optical waveguide according to one embodiment of the present invention. The developing process in step (5) allows the latent image formed in step (4) to be developed. Since the core resin composition functions as a negative-type photosensitive resin composition, as shown in Figure 6, the exposed portion 111 is not removed by the developing process, while the unexposed portion 112 (see Figure 5) is removed. The exposed portion 111 of the second resin composition layer remaining after development may have the same planar shape as the mask pattern of the light-transmitting portion 410 (see Figure 5) of the mask 400 used in step (4).

[0208] The development method typically involves a wet development method in which the second resin composition layer 110 is brought into contact with a developer. An organic solvent is usually used as the developer.

[0209] Organic solvents used as developing solutions include, for example, acetone, ethyl acetate, propylene glycol monomethyl ether acetate, alkoxyethanol having an alkoxy group with 1 to 4 carbon atoms, ethyl alcohol, isopropyl alcohol, butyl alcohol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, cyclopentanone, and cyclohexanone.

[0210] The temperature of such organic solvents can be adjusted according to the developing properties. Furthermore, such organic solvents can be used alone or in combination of two or more types. Examples of organic solvent-based developers used alone include propylene glycol monomethyl ether acetate, 1,1,1-trichloroethane, N-methylpyrrolidone, N,N-dimethylformamide, cyclohexanone, cyclopentanone, methyl isobutyl ketone, and γ-butyrolactone.

[0211] The developing solution may contain additives such as surfactants and defoamers, if necessary, to improve the developing action.

[0212] The development time is preferably 10 seconds to 5 minutes. The temperature of the developer solution during development is not particularly specified, but is preferably 20°C or higher, preferably 50°C or lower, and more preferably 40°C or lower.

[0213] Examples of development methods include the paddle method, spray method, immersion method, brushing method, slapping method, and ultrasonic method. Among these, the spray method is suitable for improving resolution. When using the spray method, a spray pressure of 0.05 MPa to 0.3 MPa is preferred.

[0214] After development using the developer, the second resin composition layer 110 may be rinsed. It is preferable to rinse with a solvent different from the developer. The rinsing time is preferably 5 seconds to 1 minute.

[0215] Furthermore, after development using a developing solution, desmear treatment may be performed to remove unexposed areas 112 that could not be removed by development. Desmear treatment may be carried out according to various methods known to those skilled in the art that are used in the manufacture of printed circuit boards.

[0216] <Step (6)> A method for manufacturing an optical waveguide according to one embodiment of the present invention includes, after step (5), step (6) of curing a second resin composition layer.

[0217] Figure 7 is a schematic cross-sectional view illustrating step (6) of a method for manufacturing an optical waveguide according to one embodiment of the present invention. By curing the second resin composition layer 110 in step (6), a core layer 100 as a cured second resin composition layer is obtained on the first cladding layer 220, as shown in Figure 7.

[0218] <Step (7)> ​​A method for manufacturing an optical waveguide according to one embodiment of the present invention includes, after step (6), step (7) of forming a third resin composition layer containing a cladding resin composition on a second resin composition layer.

[0219] Figure 8 is a schematic cross-sectional view illustrating step (7) of a method for manufacturing an optical waveguide according to one embodiment of the present invention. In step (7), as shown in Figure 8, a third resin composition layer 230 containing a cladding resin composition is formed on the core layer 100. The third resin composition layer 230 is usually formed to cover the entire surface of the circumferential surface of the core layer 100 that is not in contact with the first cladding layer 220. Therefore, the third resin composition layer 230 is formed to cover the core layer 100 and is also formed on the first cladding layer 220.

[0220] There are no particular restrictions on the method for forming the third resin composition layer 230. For example, the third resin composition layer 230 may be formed by applying a photosensitive cladding resin composition onto the core layer 100 (and, if necessary, onto the first cladding layer 220). The application of the cladding resin composition for forming the third resin composition layer 230 can be carried out in the same manner as the application of the cladding resin composition for forming the first resin composition layer 210. Furthermore, after the application of the cladding resin composition, the third resin composition layer 230 may be dried if necessary. The drying of the third resin composition layer 230 can be carried out using the same method and conditions as the drying of the first resin composition layer 210.

[0221] The third resin composition layer 230 formed on the core layer 100 in step (7) contains a photosensitive resin composition for cladding, preferably containing only the photosensitive resin composition for cladding.

[0222] <Step (8)> A method for manufacturing an optical waveguide according to one embodiment of the present invention includes, after step (7), step (8) of curing a third resin composition layer. The curing of the third resin composition layer 230 in step (8) can usually be carried out in the same manner as the curing of the first resin composition layer 210 in step (2).

[0223] Figure 9 is a schematic cross-sectional view illustrating step (8) of a method for manufacturing an optical waveguide according to one embodiment of the present invention. By curing the third resin composition layer 230 in step (8), a cured third resin composition layer 240 is obtained on the core layer 100, as shown in Figure 9. This cured third resin composition layer 240 forms a part of the cladding layer 200 and may hereinafter be referred to as the "second cladding layer" 240. The cladding layer 200 is then formed from this second cladding layer 240 and the first cladding layer 220. Therefore, an optical waveguide 10 can be obtained comprising a cladding layer 200 including the first cladding layer 220 and the second cladding layer 240, and a core layer 100 provided within this cladding layer 200.

[0224] <Step (9)> The method for manufacturing an optical waveguide according to one embodiment of the present invention may further include step (9) of forming a conductor layer as a wiring layer after step (8). The location where the conductor layer is formed is arbitrary; for example, the conductor layer may be formed inside a trench or hole, or for example, the conductor layer may be formed on the second cladding layer 240. The conductor layer is preferably formed by plating. Furthermore, before forming the conductor layer by plating, the location where the conductor layer is to be formed may be subjected to a roughening treatment.

[0225] Figure 10 is a schematic cross-sectional view illustrating step (9) of the method for manufacturing an optical waveguide according to one embodiment of the present invention. In this embodiment, an example of forming a conductor layer on the second cladding layer 240 is shown and explained as shown in Figure 10.

[0226] The procedure and conditions for the roughening treatment are not particularly limited. For example, the second cladding layer 240 can be roughened by performing swelling treatment with a swelling solution, roughening treatment with an oxidizing agent, and neutralization treatment with a neutralizing solution in this order.

[0227] Examples of swelling solutions used for roughening treatment include alkaline solutions and surfactant solutions, with alkaline solutions being preferred. Sodium hydroxide solution and potassium hydroxide solution are more preferred as alkaline solutions. Examples of commercially available swelling solutions include "Swelling Dip Securigans P" and "Swelling Dip Securigans SBU" manufactured by Atotec Japan. The swelling treatment with the swelling solution is not particularly limited, but can be carried out by immersing the area where the conductive layer will be formed in a swelling solution at 30°C to 90°C for 1 to 20 minutes. From the viewpoint of suppressing the swelling of the resin of the second cladding layer 240 to an appropriate level, it is preferable to immerse the area where the conductive layer will be formed in a swelling solution at 40°C to 80°C for 5 to 15 minutes.

[0228] Examples of oxidizing agents used in the roughening treatment include alkaline permanganate solutions obtained by dissolving potassium permanganate or sodium permanganate in an aqueous solution of sodium hydroxide. The roughening treatment with an oxidizing agent such as an alkaline permanganate solution is preferably carried out by immersing the second cladding layer 240 in an oxidizing agent solution heated to 60°C to 100°C for 10 to 30 minutes. Furthermore, the concentration of permanganate in the alkaline permanganate solution is preferably 5% to 10% by mass. Examples of commercially available oxidizing agents include alkaline permanganate solutions such as "Concentrate Compact CP" and "Dosing Solution Securigans P" manufactured by Atotec Japan.

[0229] As the neutralizing solution used for roughening treatment, an acidic aqueous solution is preferred, and a commercially available example is "Reduction Solution Securigant P" manufactured by Attec Japan. Treatment with the neutralizing solution can be carried out by immersing the treated surface, which has been roughened with an oxidizing agent, in a neutralizing solution at 30°C to 80°C for 5 to 30 minutes. From the viewpoint of workability, it is preferable to immerse the object that has been roughened with an oxidizing agent in a neutralizing solution at 40°C to 70°C for 5 to 20 minutes.

[0230] The arithmetic mean roughness Ra of the surface of the second cladding layer 240 after roughening treatment is preferably 500 nm or less, more preferably less than 400 nm, even more preferably 200 nm or less, and even more preferably less than 200 nm. The lower limit is not particularly limited and can be, for example, 1 nm or more, 2 nm or more, etc.

[0231] After the roughening treatment is completed, a conductor layer 500 is formed on the roughened second cladding layer 240. Specifically, a conductor layer having a desired shape can be formed by plating the roughened areas using methods such as the semi-additive method or the fully additive method. From the viewpoint of ease of manufacturing, it is preferable to form the conductor layer using the semi-additive method. An example of forming the conductor layer using the semi-additive method is shown below.

[0232] A plating seed layer is formed on the roughened areas by electroless plating. Next, a second mask pattern is formed on the formed plating seed layer, exposing a portion of the plating seed layer according to the desired shape. After forming a metal layer on the exposed plating seed layer by electroplating, the second mask pattern is removed. Subsequently, the unnecessary plating seed layer can be removed by etching or other means to form a conductor layer having the desired wiring pattern.

[0233] The method for manufacturing the optical waveguide 10 may include any additional steps in combination with the steps described above. For example, the method for manufacturing the optical waveguide 10 may further include a step of forming a protective layer (not shown). The method for manufacturing the optical waveguide 10 may further include a step of forming trenches or holes (not shown). The method for manufacturing the optical waveguide 10 may further include a step of dicing the manufactured optical waveguide 10.

[0234] The manufacturing method for the optical waveguide 10 may involve repeatedly performing the steps described above. For example, steps (1) to (8) (including step (9) as needed) may be repeated to manufacture a multilayer optical waveguide on a substrate 300 having alternating core layers and cladding layers in the thickness direction.

[0235] [Optoelectric Mixed-Platform Substrate and Method for Manufacturing the Same] An optoelectric mixed-platform substrate according to one embodiment of the present invention comprises the optical waveguide described above. Typically, an optoelectric mixed-platform substrate comprises an optical waveguide and an electrical circuit board. The electrical circuit board may comprise electronic components and wiring connected to the electronic components. Examples of electronic components include passive components such as capacitors, inductors, and resistors; active components such as semiconductor chips; and so on. The optical waveguide and the wiring of the electrical circuit board may be connected via a photoelectric conversion element. The photoelectric conversion element may include a combination of a light-emitting element capable of converting electricity into light (e.g., a surface-emitting light-emitting diode) and a light-receiving element capable of converting light into electricity (e.g., a photodiode). Furthermore, the optoelectric mixed-platform substrate may also comprise optical elements such as mirrors for adjusting the optical path.

[0236] A preferred example of an optoelectronic mixed-signal substrate is one that includes a chip formed on a silicon wafer with an optical integrated circuit. This chip is expected to be put into practical use early on using silicon photonics, and is anticipated to be mounted on semiconductor packages, for example. An optoelectronic mixed-signal substrate containing this chip includes, for example, an electrical circuit board, a chip mounted on the electrical circuit board, and an optical waveguide. The optical waveguide can be used to connect the wiring of the electrical circuit board to the chip, or to connect multiple chips.

[0237] In chips manufactured using silicon photonics, light with wavelengths of 1310 nm and 1550 nm is commonly used, with 1310 nm being particularly prevalent (Sho Yoshida, Daisuke Suganuma, Takaaki Ishigure, "Fabrication and Low-Loss Improvement of Single-Mode Polymer Waveguides by Mosquito Method," 28th Spring Conference of the Japan Society for Electronics Packaging, 2014). Therefore, it is preferable that the optical waveguide is capable of transmitting light with wavelengths of 1310 nm and 1550 nm or close to them, and for example, it is preferable that it is capable of transmitting light with wavelengths of 1300 nm to 1320 nm. According to the optical waveguide of the embodiment described above, it is possible to transmit light of these wavelengths.

[0238] Generally, single-mode optical waveguides can achieve faster transmission speeds than multi-mode waveguides. Therefore, from the viewpoint of high-speed transmission, single-mode optical waveguides are preferred as optical waveguides applied to mixed-signal optical circuits. In single-mode optical waveguides, it is preferable that the width and / or thickness of the core layer be small. For example, it is preferable to form a core layer with a width and / or thickness of 10 μm or less, 7 μm or less, or 5 μm or less. Furthermore, optical waveguides with such small width and / or thickness core layers are also preferable from the viewpoint of increasing the design flexibility of the package when the optical waveguide is applied to a semiconductor package.

[0239] On the other hand, when connecting multiple optical-electric mixed-signal substrates, these substrates may be connected via optical fibers. For example, multiple optical-electric mixed-signal substrates may be installed in a rack and connected to each other with optical fibers. Multimode optical fibers are the mainstream for connecting substrates in this way. Therefore, from the standpoint of enabling connection with such optical fibers, a multimode optical waveguide may be adopted as the optical waveguide provided in the optical-electric mixed-signal substrate.

[0240] From the standpoint of increasing versatility, it is desirable that the optical waveguides provided on the optoelectronic mixed-signal substrate be applicable to both single-mode and multi-mode optical waveguides. Furthermore, it is desirable to reduce the minimum width of the core layer of these optical waveguides to increase the degree of freedom of the line width of the core layer. According to the optical waveguides of the embodiments described above, by using the core resin composition of the present invention in the core layer, a fine core can be formed, so the minimum width of the core layer can be reduced. In addition, according to the optical waveguides of the embodiments described above, both single-mode and multi-mode optical waveguides can be obtained. Therefore, the optical waveguides of the embodiments described above are applicable to a wide range of applications. And, while being applicable to such a wide range of applications, they can suppress optical transmission loss, so the optical waveguides of the embodiments described above are suitable for application to optoelectronic mixed-signal substrates.

[0241] Since the photoelectric mixed-signal substrate includes the optical waveguide described above, the method for manufacturing the photoelectric mixed-signal substrate includes the same method as the method for manufacturing the optical waveguide.

[0242] [Semiconductor Device] A semiconductor device according to one embodiment of the present invention comprises the above-described photoelectric mixed-signal substrate. Examples of such semiconductor devices include various semiconductor devices used in electrical products (e.g., computers, mobile phones, smartphones, tablet devices, wearable devices, digital cameras, medical equipment, and televisions) and vehicles (e.g., motorcycles, automobiles, trains, ships, and aircraft).

[0243] The present invention will be specifically described below with reference to examples. However, the present invention is not limited to these examples. In the following description, "parts" and "%" refer to "parts by mass" and "mass%" respectively, unless otherwise specified. Unless otherwise specified, the temperature and pressure conditions were room temperature (25°C) and atmospheric pressure (1 atm).

[0244] <Synthesis Example 1: Synthesis of Epoxy Group-Containing Organopolysiloxane 1> As starting materials, 625 parts by mass of 1,1,3,3-tetramethyldisiloxane, 504 parts by mass of hexamethyldisiloxane, 422 parts by mass of partially hydrolyzed oligomer of tetramethoxysilane (Mitsubishi Chemical Corporation's "Methyl Silicate MS51"), 987 parts by mass of tetrahydrofuran as a solvent, and a mixture of 115 parts by mass of 1N hydrochloric acid and 115 parts by mass of methanol as a catalyst and water were used, and hydrolysis condensation was carried out at 30°C. Next, 938 parts by mass of heptane was added to the reaction product, and after removing the hydrochloric acid by washing with desalted water, the solvent was removed using a rotary evaporator at 76°C under reduced pressure of 15 torr until no more solvent distillation was visible. Next, the mixture was heated at 120°C under reduced pressure of 0.15 torr for 2 hours to obtain 727 parts by mass of the precursor of organopolysiloxane 1.

[0245] 150 parts by mass of the organopolysiloxane 1 precursor obtained by the above procedure was dissolved in 331 parts by mass of toluene. To this solution, 0.2 parts by mass of a platinum(0)-1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex xylene solution with a platinum concentration of 2% by mass was added and the mixture was stirred. After heating the solution to 80°C, 208 parts by mass of allyl glycidyl ether was added dropwise over 1 hour, and the temperature was further increased to 120°C and heated for 1 hour. The heated solution was allowed to cool to near room temperature, 150 parts by mass of silica gel was added and the mixture was stirred for 30 minutes, and then filtered using a membrane filter with a pore size of 0.2 μm. The obtained filtrate was removed by distillation using a rotary evaporator under reduced pressure of 15 torr at 60°C until no more solvent was visible to the naked eye. Next, the mixture was heated at 80°C under reduced pressure of 0.15 torr for 2 hours to obtain 287 parts by mass of epoxy group-containing organopolysiloxane 1. The obtained epoxy group-containing organopolysiloxane 1 contains 32 mol% Q units per 100 mol% of the total silicon atoms in the epoxy group-containing organopolysiloxane 1. The epoxy group equivalent of epoxy group-containing organopolysiloxane 1 was 247 g / eq.

[0246] <Synthesis Example 2: Synthesis of Organopolysiloxane Compound 2> 21.6 parts by mass of diphenylsilanediol, 24.8 parts by mass of 3-methacrylateoxypropyltrimethoxysilane, and 19.2 parts by mass of toluene as a solvent were placed in a 200 ml round-bottom flask. A condenser was attached to the round-bottom flask, and the air in the flask was replaced with nitrogen using a nitrogen balloon. Next, the mixture in the round-bottom flask was gradually heated from room temperature to 50°C using an oil bath. After confirming that the temperature of the mixture had stabilized at 50°C, 0.038 parts by mass (0.0002 mol) of barium hydroxide monohydrate (manufactured by Aldrich) as a catalyst was added to the mixture, and de-alcoholization condensation was carried out for 2 days while maintaining the temperature at 50°C. Next, the reaction product was cooled to room temperature and filtered using a membrane filter with a pore size of 0.2 μm. The obtained filtrate was heated to 50°C, and toluene and the by-product methanol were removed under vacuum using a rotary evaporator. Next, the solution was returned to normal pressure (atmospheric pressure) to remove toluene, yielding 36 parts by mass of organopolysiloxane compound 2. The obtained organopolysiloxane compound 2 contains T units but does not contain epoxy groups.

[0247] <Synthesis Example 3: Synthesis of Organopolysiloxane Compound 3> 64.59 parts by mass of diphenylsilanediol, 37.085 parts by mass of 3-methacrylateoxypropyltrimethoxysilane, and 32.604 parts by mass of 3,3,3-trifluoropropyltrimethoxysilane were charged into a 200 ml round-bottom flask. The mixture in the round-bottom flask was then heated in an oil bath at 80°C for 30 minutes. Next, 0.20 mol% of calcium hydroxide and 38.8 mol% of methanol were added to 100 mol% of the total silicon-containing compound mixture, and the mixture was heated at 80°C for 1 hour to carry out de-alcoholization condensation. The solvent was then removed under vacuum using a rotary evaporator. The reaction was then returned to atmospheric pressure and cooled to room temperature, after which it was filtered using a membrane filter with a pore size of 0.2 μm. Organopolysiloxane compound 3 was obtained by this procedure. The resulting organopolysiloxane compound 3 contains T units but does not contain epoxy groups.

[0248] <Manufacturing Example 1: Preparation of Varnish-like Photosensitive Resin Composition 1> Ten parts of epoxy resin containing a cyclic siloxane structure (Shin-Etsu Chemical Co., Ltd. "KR-470", epoxy equivalent approximately 200 g / mol.), 2.5 parts of PGMEA (propylene glycol monomethyl ether acetate), 0.1 parts of photoacid generator (Sunapro Co., Ltd. "CPI-310FG"), and 0.05 parts of photosensitizer (Air Water Performance Chemicals Inc. "UVS-1101") were mixed, and a varnish-like photosensitive resin composition 1 was prepared using a high-speed rotary mixer.

[0249] <Production Examples 2-25: Preparation of Varnish-like Resin Compositions 2-25> Varnish-like photosensitive resin compositions 2-25 were prepared in the same manner as in Production Example 1, except that each component was mixed according to the formulations shown in Tables 1-3. Details of each component listed in Tables 1-3 below are as follows. For the details of each component below, organopolysiloxanes that satisfy both requirement (α) and requirement (β) are referred to as "component (A)", organopolysiloxanes that satisfy only requirement (α) are referred to as "component (B)", and organopolysiloxanes that satisfy only requirement (β) are referred to as "component (C)".

[0250] (A) Components; Organopolysiloxanes that satisfy both requirement (α) and requirement (β): "KR-470": Organopolysiloxane containing a cyclic siloxane structure and an alicyclic epoxy group, manufactured by Shin-Etsu Chemical Co., Ltd., with a cured product refractive index of 1.491 at a wavelength of 1310 nm. "X-40-2701": Organopolysiloxane containing a cyclic siloxane structure and a glycidyl ether group, manufactured by Shin-Etsu Chemical Co., Ltd., with a cured product refractive index of 1.478 at a wavelength of 1310 nm. "X-40-2678": Organopolysiloxane containing a cyclic siloxane structure and an alicyclic epoxy group, manufactured by Shin-Etsu Chemical Co., Ltd., with a cured product refractive index of 1.467 at a wavelength of 1310 nm. - "X-40-2728": Organopolysiloxane containing a cyclic siloxane structure and a glycidyl ether group, manufactured by Shin-Etsu Chemical Co., Ltd., the refractive index of the cured product at a wavelength of 1310 nm is 1.478. - "Synthesis Example 1": Epoxy group-containing organopolysiloxane 1 obtained in Synthesis Example 1, containing Q units and a glycidyl ether group, the refractive index of the cured product at a wavelength of 1310 nm is 1.460.

[0251] (B); Organopolysiloxanes that satisfy only requirement (α) - "Synthesis Example 2": Contains 2 siloxane compounds obtained in Synthesis Example 2, T units, no epoxy groups, and the refractive index of the cured product at a wavelength of 1310 nm is 1.539 - "Synthesis Example 3": Contains 3 siloxane compounds obtained in Synthesis Example 3, T units, no epoxy groups, and the refractive index of the cured product at a wavelength of 1310 nm is 1.524

[0252] (C); Organopolysiloxanes that meet only requirement (β): "X-22-2000": A linear organopolysiloxane containing epoxy groups and aromatic rings in the side chains, manufactured by Shin-Etsu Chemical Co., Ltd., free of T and Q units, with a refractive index of 1.440 at a wavelength of 1310 nm. "KF-105": A linear organopolysiloxane containing epoxy groups at both ends, manufactured by Shin-Etsu Chemical Co., Ltd., free of T and Q units, with a refractive index of 1.420 at a wavelength of 1310 nm. "X-22-163": A linear organopolysiloxane containing epoxy groups at both ends, manufactured by Shin-Etsu Chemical Co., Ltd., free of T and Q units, with a refractive index of 1.455 at a wavelength of 1310 nm. • "X-22-2046": A linear organopolysiloxane containing alicyclic epoxy groups in its side chains, manufactured by Shin-Etsu Chemical Co., Ltd., free of T and Q units, with a cured product refractive index of 1.475 at a wavelength of 1310 nm.

[0253] (D); Photopolymerization initiator "CPI-310FG": Photoacid generator, manufactured by Sunapro, a sulfonium salt (onium salt compound) having a cation with the structure represented by the following formula.

[0254]

[0255] • "Irgacure OXE04": Photoradical generator, manufactured by BASF.

[0256] (E); Photosensitizer "UVS-1101": A compound having the structure represented by the following formula, manufactured by Air Water Performance Chemicals Inc.

[0257]

[0258] (F); Silane coupling agent "KBM-403": Silane coupling agent containing an epoxy group, manufactured by Shin-Etsu Chemical Co., Ltd., 3-glycidoxypropyltrimethoxysilane

[0259] (G); Other organopolysiloxanes • "KP-912": A linear organopolysiloxane containing D units, manufactured by Shin-Etsu Chemical Co., Ltd., free of T and Q units, and free of epoxy groups. • "KP-913": A linear organopolysiloxane containing D units, manufactured by Shin-Etsu Chemical Co., Ltd., free of T and Q units, and free of epoxy groups. • "KP-914": A linear organopolysiloxane containing D units, manufactured by Shin-Etsu Chemical Co., Ltd., free of T and Q units, and free of epoxy groups.

[0260] (H); Organic solvent "PGMEA": Propylene glycol monomethyl ether acetate

[0261] In Tables 1 to 3, the parts by mass of components (A), (B), (C), (D), (E), (F), and (G) are the parts by mass converted to non-volatile components. Also, in Tables 1 to 3, "Refractive index of the cured product of each component individually" represents the refractive index of the cured product of each component individually at a wavelength of 1310 nm, and "Refractive index of the cured product of the photosensitive resin composition" represents the refractive index of the cured product of each photosensitive resin composition at a wavelength of 1310 nm.

[0262]

[0263]

[0264]

[0265] <Test Example 1; Measurement of the refractive index of the cured product> (1-1) Measurement of the refractive index of the cured products of individual components used in the preparation of the photosensitive resin composition For each of the photosensitive resin compositions in Manufacturing Examples 1 to 25, components (A), (B), and (C) used in the preparation of each component were coated onto a silicon wafer to form a resin layer with a thickness of 10 μm. Specifically, 1 part of a PGMEA solution containing 20% ​​by mass of the non-volatile component of a photopolymerization initiator (IMG Corporation's "Omnirad 379EG") was added to 100 parts by mass of each component to prepare a photosensitive resin mixture. The prepared resin mixture was coated onto a silicon wafer to obtain a resin layer with a thickness of 10 μm. The formed resin layer was exposed using a projection exposure apparatus (Ushio Inc.'s "UFX-2240") at a wavelength of 365 nm and an illuminance of 35 mW / cm. ２ and exposure dose 5 J / cm ２ After UV exposure under these conditions, the material was placed in a clean oven, heated from room temperature to 190°C, and then subjected to a 90-minute heat treatment in an atmospheric environment to cure the resin layer and obtain a cured product. The refractive index n of the obtained cured product (measurement wavelength: 1310 nm) was measured using a 2010M type prism coupler (manufactured by Metricon) with 1310 nm laser light at room temperature and atmospheric pressure.

[0266] (1-2) Measurement of the refractive index of the cured photosensitive resin composition The varnish-like photosensitive resin compositions 1 to 25 produced in each production example were applied to a silicon wafer to obtain a resin composition layer with a thickness of 10 μm. The formed resin composition layer was exposed using a projection exposure apparatus (UFX-2240 manufactured by Ushio Inc.) at a wavelength of 365 nm and an illuminance of 35 mW / cm. ２ and exposure dose 5 J / cm ２ After ultraviolet exposure under these conditions, the material was placed in a clean oven, heated from room temperature to 190°C, and then subjected to a 90-minute heat treatment in an atmospheric environment to cure the resin composition layer and obtain a cured product. The refractive index n of the obtained cured product (measurement wavelength: 1310 nm) was measured using a 1310 nm laser beam with a 2010M type prism coupler (manufactured by Metricon) at room temperature and atmospheric pressure.

[0267] <Examples 1-18 and Comparative Examples 1-2; Formation of Optical Waveguides> Optical waveguides for Examples 1-18 and Comparative Examples 1-2 were obtained using the varnish-like photosensitive resin compositions obtained in Production Examples 1-25. In each example and comparative example, the combination of the core resin composition and the cladding resin composition is as shown in Tables 4-7. In Tables 4-7, "exposure amount during core formation" refers to the exposure amount (J / cm²) when exposed through a quartz glass mask during the formation of the core layer. ２ ) indicates.

[0268] <Test Example 2; Measurement of Optical Transmission Loss> (2-1) Formation of the First Cladding Layer In each example and comparative example, the cladding resin composition was applied to a silicon wafer by spin coating so that the thickness of the resin composition layer after drying was 10 μm. After applying the resin composition, it was dried at 90°C for 3 minutes to form the resin composition layer I. A projection exposure apparatus (UFX-2240, manufactured by Ushio Inc.) was used on the resin composition layer I at a wavelength of 365 nm and an illuminance of 35 mW / cm. ２ and exposure dose 5 J / cm ２ After UV exposure, the material was placed in a clean oven, heated from room temperature to 190°C, and then subjected to a 90-minute heat treatment in an atmospheric environment to cure the resin composition layer I and form the first cladding layer. After forming the first cladding layer, a plasma device (Yamato Scientific Co., Ltd. "PDC510") was used to cure the material at 100W, O ２ Plasma irradiation was performed for 30 seconds under the condition of a gas flow rate of 50 mL / min. Through the above procedure, an intermediate laminate A1 having a silicon wafer / first cladding layer in this order was obtained.

[0269] (2-2) Formation of the core layer In each example and comparative example, the core resin composition was applied to the first cladding layer of the intermediate laminate A1 by spin coating so that the thickness of the resin composition layer after drying was 5 μm. After applying the core resin composition, it was dried at 90°C for 3 minutes to form the resin composition layer II. The resin composition layer II was exposed using a projection exposure apparatus (UFX-2240 manufactured by Ushio Inc.) at a wavelength of 365 nm and an illuminance of 35 mW / cm². ２Under these conditions, ultraviolet exposure was performed with an appropriate exposure dose (an exposure dose that would not cause the core layer to disappear during spray development, as described later). For exposure, a quartz glass mask was used to draw multiple straight lines with a length of 5 cm and a line and space (L / S) of 5 μm / 100 μm. In the L / S of this quartz glass mask, the lines correspond to the width of the core layer, and the spaces correspond to the spacing between the core layers. After exposure, the resin composition layer II was dried at 100°C for 3 minutes. Next, the entire surface of the dried resin composition layer II was spray developed for 1 minute at a spray pressure of 0.2 MPa using 23°C PGMEA as the developer. After spray development, the resin composition layer II was exposed using a projection exposure device (UFX-2240, manufactured by Ushio Inc.) at a wavelength of 365 nm and an illuminance of 35 mW / cm². ２ and exposure dose 5 J / cm ２ After UV exposure, the material was placed in a clean oven and heated from room temperature to 190°C. After reaching 190°C, a 90-minute heat treatment was performed in an atmospheric environment to cure the resin composition layer II and form the core layer. After the core layer was formed, a plasma device (Yamato Scientific Co., Ltd. "PDC510") was used to cure the material at 100W, O ２ Plasma irradiation was performed for 30 seconds under the condition of a gas flow rate of 50 mL / min. Through the above procedure, an intermediate laminate A2 comprising a silicon wafer, a first cladding layer, and a core layer in that order was obtained.

[0270] (2-3) Formation of the Second Cladding Layer In each example and comparative example, the cladding resin composition was applied to the core layer and the first cladding layer of the intermediate laminate A2 by spin coating so that the thickness of the dried resin composition layer was 10 μm. After applying the resin composition, it was dried at 90°C for 3 minutes to form the resin composition layer III. For the resin composition layer III, a projection exposure apparatus (UFX-2240 manufactured by Ushio Inc.) was used with a wavelength of 365 nm and an illuminance of 35 mW / cm². ２ and exposure dose 5 J / cm ２After UV exposure, the sample was placed in a clean oven, heated from room temperature to 190°C, and then subjected to a 90-minute heat treatment in an atmospheric environment to cure the resin composition layer III and form a second cladding layer. Through these operations, a sample laminate A3 was obtained, comprising a silicon wafer, a first cladding layer, a core layer, and a second cladding layer in that order. In this sample laminate A3, the combination of the first cladding layer and the second cladding layer constitutes the cladding layer. Thus, an optical waveguide including the cladding layer and the core layer within the cladding layer was obtained.

[0271] (2-4) Preparation of the test substrate From the sample laminate A3 manufactured by the above procedure, the portion in which the core layer was formed, that is, the core layer with a 5 cm linear pattern drawn on it and the surrounding cladding layer were cut out to obtain a test substrate A4 equipped with an optical transmission path. The cutting conditions were as follows: • Dicing device: DAD3221 (Disco Corporation) • Blade: ZH14-SD4000-VI-50 • Spindle rotation speed: 30 K / min • Cutting speed: 5 mm / sec • Blade height: 0.060 mm • Dicing tape: T-80W (Denka Corporation, 80 umt)

[0272] (2-5) Measurement of Optical Transmission Loss of Calibration Optical System As described later, the transmission loss of the optical system was measured using a configuration that excluded the test substrate A4 and the focusing module from the optical system used for measuring the transmission loss of test substrate A4. Specifically, a calibration optical system was obtained by connecting a light source (1310 nm light source, THORLABS "LPSC-1310-FC") and a photodetector (Keysight optical power meter "N7742") via an optical fiber (incident fiber) on a vibration isolation table covered with a blackout curtain. The light source was made to emit light, and the intensity of the light entering the photodetector was measured by the photodetector to measure the loss of this calibration optical system.

[0273] (2-6) Measurement of optical transmission loss A test substrate A4 was placed on a vibration isolation table covered with a dark curtain. A focusing module (numerical aperture 0.31) was connected to one end (incident end) of the optical waveguide of test substrate A4, and a light source (1310 nm light source, THORLABS "LPSC-1310-FC") was further connected to the focusing module via an optical fiber (incident fiber). Another focusing module (numerical aperture 0.39) was connected to the other end (exit end) of the optical waveguide of test substrate A4, and a photodetector (Keysight optical power meter "N7742") was further connected to the focusing module via an optical fiber (exit fiber). Through the above operation, an optical system was obtained in which light emitted from the light source passes through the optical fiber (incident fiber), focusing module, optical waveguide, focusing module, and optical fiber (exit fiber) in that order before entering the photodetector. Hereinafter, this optical system may be referred to as the "sample optical system". The light source was illuminated, and the intensity of the light entering the photodetector was measured by the photodetector to determine the loss of the sample optical system.

[0274] The loss of the optical waveguide contained in test substrate A4 was determined by subtracting the loss of the calibration optical system from the loss of the sample optical system.

[0275] After measuring the loss of the 5 cm optical waveguide as described above, the waveguide was cut to 4 cm and the same measurement was performed. Subsequently, the optical waveguide was cut to 3 cm and the measurement was repeated, so that the measured values ​​were calculated for optical waveguides of 5 cm, 4 cm, and 3 cm lengths. The measurement results were then plotted on a coordinate system with the length of the optical waveguide on the horizontal axis and the loss of the optical waveguide on the vertical axis to obtain the coordinates of three points representing the measurement results. The approximate straight line between these three points was calculated using the least squares method, and the slope of this approximate straight line was determined as the loss per unit distance of the optical waveguide (optical transmission loss). In each example and comparative example, measurements were performed on five optical waveguides, and the average value (dB / cm) of the optical transmission loss of the optical waveguide was calculated.

[0276] In Comparative Example 1, the optical waveguide's end face was rough during cutting (related to <Test Example 3; Evaluation of Processability of Optical Waveguides> below), making it impossible to measure the optical transmission loss of the optical waveguide. Furthermore, in Comparative Example 2, the exposure dose was 8 J / cm² during the operation described in (2-2) above. ２ Even with UV exposure, uncured resin remained on the surface of the core layer, and the core layer disappeared during development, making it impossible to form an optical waveguide. Therefore, in Comparative Example 2, it was also impossible to measure the optical transmission loss of the optical waveguide.

[0277] <Test Example 3: Evaluation of Processability of Optical Waveguides> In the operation described in (2-6) above, the wafer powder adhering to the end face of the cut optical waveguide was gently wiped off with a cloth dampened with ethanol. The processability of the optical waveguide was evaluated based on the observation results of the end face after wiping with the cloth, according to the following evaluation criteria. The processability of the optical waveguide was evaluated for both the core layer and the cladding layer. In Comparative Example 2, the core layer disappeared during spray development, making it impossible to form an optical waveguide, and therefore the processability of the optical waveguide could not be evaluated.

[0278] [Evaluation Criteria for Processability of Optical Waveguides] "○": The end face of the optical waveguide remains intact and clean. "×": The end face of the optical waveguide becomes rough and uneven.

[0279] <Test Example 4: Calculation of Fresnel Loss between Optical Fiber and Optical Waveguide> The Fresnel loss that occurs when connecting an optical fiber and an optical waveguide was calculated using the refractive index of the cured resin composition for the core. Specifically, the Fresnel reflectance T when light is perpendicularly incident from the optical fiber to the core layer of the optical waveguide was calculated using the following equation (1'). In equation (1'), n ｃｏｒｅ This represents the refractive index of the core layer of the optical waveguide at a wavelength of 1310 nm (i.e., the refractive index of the cured resin composition for the core at a wavelength of 1310 nm). The refractive index of the optical fiber was assumed to be 1.468. T = {(n ｃｏｒｅ -1.468) ÷ (n ｃｏｒｅ (+1.468) ２ …(1')

[0280] Using the Fresnel reflectance T obtained by equation (1') above, the Fresnel loss L when light is perpendicularly incident from the optical fiber to the core layer of the optical waveguide was calculated using the following equation (2): L = (-10) × log １０ (1-T) ... (2)

[0281] <Test Example 5: Evaluation of Patternability of Optical Waveguides> In the operation described in (2-2) above, the patternability of the optical waveguide was evaluated from the exposure value at which the core layer did not disappear due to spray development. Specifically, the exposure value was 0.2 J / cm². ２ In UV exposure, a "◎" rating was given if the core layer did not disappear during spray development. The exposure dose was 2 J / cm². ２ In UV exposure, a "○" was given if the core layer did not disappear after spray development. The exposure dose was 8 J / cm². ２ In UV exposure, a "△" rating was given if the core layer did not disappear after spray development. The exposure dose was 8 J / cm². ２ In ultraviolet exposure, cases where the core layer disappeared due to spray development were evaluated as "×".

[0282] <Test Example 6: Evaluation of Substrate Adhesion of Optical Waveguides> The substrate adhesion of optical waveguides was evaluated using the intermediate laminate A1 obtained by the operation described in (2-1) above. Specifically, in accordance with JIS K 5600-5-6, grid-like cuts were made in the first cladding layer of intermediate laminate A1 at 1 mm intervals, forming 10 hardened pieces in the vertical direction and 10 in the horizontal direction, for a total of 100 pieces. Here, a hardened piece represents each part of the first cladding layer partitioned by the cuts. These 100 hardened pieces were observed with an optical microscope, and the number of hardened pieces that peeled off from the silicon wafer was measured. A smaller number of hardened pieces that peeled off from the silicon wafer indicates better substrate adhesion of the optical waveguide. The substrate adhesion of the optical waveguide was evaluated according to the following evaluation criteria.

[0283] [Evaluation Criteria for Substrate Adhesion of Optical Waveguides] "○": The number of cured fragments that peel off from the silicon wafer is 0. "△": The number of cured fragments that peel off from the silicon wafer is 1 or more but less than 50. "×": The number of cured fragments that peel off from the silicon wafer is 50 or more.

[0284] The combinations of core resin compositions and cladding resin compositions used in each example and comparative example, as well as the evaluation results, are shown in Tables 4 to 7 below.

[0285]

[0286]

[0287]

[0288]

[0289] 10 Optical waveguide 100 Core layer 100A Incident end of core layer 100B Exit end of core layer 100I Interface between core layer and cladding layer 110 Second resin composition layer 111 Exposed area of ​​second resin composition layer 112 Unexposed area of ​​second resin composition layer 200 Cladding layer 210 First resin composition layer 220 First cladding layer (cured first resin composition layer) 230 Third resin composition layer 240 Second cladding layer (cured third resin composition layer) 300 Substrate 400 Mask 410 Light-transmitting area of ​​mask 420 Light-shielding area of ​​mask 500 Conductor layer P Light (active light)

Claims

1. A photosensitive resin composition for manufacturing optical waveguides, comprising an organopolysiloxane that satisfies both requirement (α) and requirement (β) below, or a combination of an organopolysiloxane that satisfies only requirement (α) of the following requirements (α) and requirement (β), and an organopolysiloxane that satisfies only requirement (β) of the following requirements (α) and requirement (β). Requirement (α): Contains at least one of the following: a T unit, in which one silicon atom is bonded to three siloxane bonds and one organic group; a Q unit, in which one silicon atom is bonded to four siloxane bonds; and a cyclic siloxane structure. Requirement (β): Contains an epoxy group, and the refractive index of the cured product at a wavelength of 1310 nm is less than 1.

5.

2. The photosensitive resin composition according to claim 1, comprising an organopolysiloxane that satisfies both requirement (α) and requirement (β).

3. The photosensitive resin composition according to claim 1, comprising a combination of an organopolysiloxane that satisfies only requirement (α) among requirement (α) and requirement (β), and an organopolysiloxane that satisfies only requirement (β) among requirement (α) and requirement (β).

4. The photosensitive resin composition according to claim 1, wherein requirement (β) further requires that the epoxy group contains an alicyclic epoxy group.

5. The photosensitive resin composition according to claim 1, further comprising the requirement that, in either or both of requirement (α) and requirement (β), the molecule does not contain an aromatic ring.

6. The photosensitive resin composition according to claim 1, further comprising the requirement that the molecule does not contain a fluorine atom in either or both of requirement (α) and requirement (β).

7. The photosensitive resin composition according to claim 1, further comprising a photopolymerization initiator.

8. The photosensitive resin composition according to claim 7, wherein the photopolymerization initiator comprises a photoacid generator.

9. The photosensitive resin composition according to claim 1, further comprising a silane coupling agent.

10. The photosensitive resin composition according to claim 1, further comprising an organic solvent.

11. The photosensitive resin composition according to claim 1, wherein the refractive index of the cured product of the photosensitive resin composition at a wavelength of 1310 nm is less than 1.

5.

12. A resin composition for cladding comprising the photosensitive resin composition according to any one of claims 1 to 11.

13. A photosensitive resin composition set comprising a core resin composition and a cladding resin composition, wherein the core resin composition and the cladding resin composition each comprise a photosensitive resin composition according to any one of claims 1 to 11.

14. A photosensitive resin composition set comprising a core resin composition and a cladding resin composition, wherein the core resin composition comprises the photosensitive resin composition described in claim 10, and the cladding resin composition comprises the photosensitive resin composition described in any one of claims 1 to 11.

15. A photosensitive resin composition set comprising a core resin composition and a cladding resin composition, wherein the core resin composition comprises the photosensitive resin composition according to any one of claims 1 to 11, and the cladding resin composition comprises the photosensitive resin composition according to claim 9.

16. An optical waveguide comprising a core layer and a cladding layer, wherein the core layer and the cladding layer each contain a cured product of the photosensitive resin composition described in any one of claims 1 to 11.

17. A photoelectric mixed-signal substrate comprising the optical waveguide described in claim 16.

18. A method for manufacturing an optical waveguide, comprising the steps of: forming a first resin composition layer containing a cladding resin composition; curing the first resin composition layer; forming a second resin composition layer containing a core resin composition on the first resin composition layer; subjecting the second resin composition layer to exposure treatment; subjecting the second resin composition layer to development treatment; curing the second resin composition layer; forming a third resin composition layer containing a cladding resin composition on the second resin composition layer; and curing the third resin composition layer, wherein the core resin composition and the cladding resin composition contain the photosensitive resin composition described in any one of claims 1 to 11.

19. A method for manufacturing an optical waveguide, comprising the steps of: forming a first resin composition layer containing a cladding resin composition; curing the first resin composition layer; forming a second resin composition layer containing a core resin composition on the first resin composition layer; subjecting the second resin composition layer to exposure treatment; subjecting the second resin composition layer to development treatment; curing the second resin composition layer; forming a third resin composition layer containing a cladding resin composition on the second resin composition layer; and curing the third resin composition layer, wherein the core resin composition and the cladding resin composition contain the photosensitive resin composition described in any one of claims 1 to 11, and the second resin composition layer contains the photosensitive resin composition described in claim 10.

20. A method for manufacturing an optical waveguide, comprising the steps of: forming a first resin composition layer containing a cladding resin composition; curing the first resin composition layer; forming a second resin composition layer containing a core resin composition on the first resin composition layer; subjecting the second resin composition layer to exposure treatment; subjecting the second resin composition layer to development treatment; curing the second resin composition layer; forming a third resin composition layer containing a cladding resin composition on the second resin composition layer; and curing the third resin composition layer, wherein the core resin composition and the cladding resin composition contain the photosensitive resin composition described in any one of claims 1 to 11, and the first resin composition layer contains the photosensitive resin composition described in claim 9.

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