Photosensitive resin composition set

Abstract

To provide a photosensitive resin composition set which enables manufacture of an optical waveguide that has a small change in optical transmission loss between before and after a reliability test, and is a single mode.SOLUTION: There is provided a photosensitive resin composition set containing a resin composition for a core and a resin composition for a clad. The resin composition for the core and the resin composition for the clad each contain: (A) a carboxyl group-containing resin (a1) or an epoxy group and radical-polymerizable group-containing resin (a2); (B) an epoxy resin; (C) a photocurable resin; and (D) a photopolymerization initiator. At least the resin composition for the clad further contains (E) an alkoxysilane compound having one or more functional groups selected from a group consisting of an epoxy group, a phenylamino group, a vinyl group and a (meth)acryloyl group. A content of the component (E) in the resin composition for the core and a content of the component (E) in the resin composition for the clad satisfy a specific relational expression.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a photosensitive resin composition set, a photosensitive resin sheet set, a photosensitive resin ink set, an optical waveguide, a method for manufacturing an optical waveguide, an opto-electrical hybrid board, and a method for manufacturing an opto-electrical hybrid board.

[0002] Technological advances such as 5G communications, autonomous driving, IoT, artificial intelligence, and big data are driving demands for ultra-high-speed and high-capacity communications. Semiconductor packages, which underpin these technologies, have traditionally supported high-speed communications by passing high-frequency current through them. However, in recent years, issues such as noise generation, communication loss, and heat generation due to high-speed communications have become apparent. To address these issues, active efforts have been made in recent years to implement optical circuits on electrical wiring boards and achieve energy-saving, low-latency, and high-speed communications (Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2019-211540 [Patent Document 2] Patent No. 5771978 Summary of the Invention [Problem to be solved by the invention]

[0004] Research into the introduction of silicon photonics is being actively conducted, particularly in data centers where high-speed transmission is required. Silicon photonics is highly compatible with conventional LSI manufacturing processes. Therefore, it is expected that the use of silicon photonics will enable the formation of nanometer-sized thin-wire waveguides at low cost, based on the technology cultivated in electronic circuit integration technology.

[0005] For example, silicon photonics promises to form optical integrated circuits on chips using thin-wire waveguides. When manufacturing an optoelectronic hybrid circuit board (OEIC) incorporating such a chip, it is necessary to provide an optical waveguide on the OEIC to extract signal light from the thin-wire waveguide within the chip and connect it to the wiring between chips. From the viewpoint of efficiently forming a fine optical waveguide, it is desirable to form the optical waveguide using a cured product of a photosensitive resin composition. Since this OEIC hybrid circuit board is required to have the same reliability as a printed circuit board, it is desirable that the change in optical transmission loss before and after reliability tests such as a moist heat resistance test (HAST test) and a heat resistance test (reflow test) be small. Furthermore, from the viewpoint of high-speed transmission, it is preferable that the optical waveguide used in the OEIC hybrid circuit be a single-mode optical waveguide. [Means for solving the problem]

[0006] The present invention has been made in view of the above-mentioned problems, and aims to provide a photosensitive resin composition set capable of producing a single-mode optical waveguide in which the change in optical transmission loss before and after a reliability test is small; a photosensitive resin sheet set; a photosensitive resin ink set; an optical waveguide; a method for producing the optical waveguide; an optical-electrical hybrid board including the optical waveguide; and a method for producing the optical-electrical hybrid board.

[0007] That is, the present invention includes the following. <1> A photosensitive resin composition set including a core resin composition and a clad resin composition, The core resin composition and the clad resin composition each comprise: (A) a carboxyl group-containing resin (a1) or an epoxy group- and radically polymerizable group-containing resin (a2), (B) epoxy resin, (C) a photocurable resin, and (D) Photopolymerization initiator Including, At least the cladding resin composition further comprises (E) an alkoxysilane compound having one or more functional groups selected from the group consisting of an epoxy group, a phenylamino group, a vinyl group, and a (meth)acryloyl group; Including, When the nonvolatile components of the core resin composition are taken as 100% by mass, the content (% by mass) of the (E) component in the core resin composition is taken as (E)core, and when the nonvolatile components of the clad resin composition are taken as 100% by mass, the content (% by mass) of the (E) component in the clad resin composition is taken as (E)clad, (E)core and (E)clad are 0.6≦(E)clad-(E)core≦10 A photosensitive resin composition set that satisfies the relationship of <2> The resin (a1) contains at least one of an aralkyl resin and a cardo resin. <1> The photosensitive resin composition set according to claim 1. <3> The resin (a2) contains a (meth)acryloyl group. <1> The photosensitive resin composition set according to claim 1. <4> (E) clad is 1 to 12 mass%, <1> ~ <3> 1. The photosensitive resin composition set according to any one of claims 1 to 9. <5> When the content of the (C) component in the core resin composition is defined as (C)core when the non-volatile components of the core resin composition are taken as 100% by mass, and when the content of the (C) component in the clad resin composition is defined as (C)clad when the non-volatile components of the clad resin composition are taken as 100% by mass, (C)core and (C)clad are 0.9≦(C)clad / (C)core≦1.5 Satisfy the relationship of <1> ~ <4> 1. The photosensitive resin composition set according to any one of claims 1 to 9. <6> When the non-volatile components of the core resin composition are taken as 100% by mass, the contents of the (A) component and the (B) component in the core resin composition are taken as (A)core and (B)core, respectively, and the (A)core and the (B)core are 0.1≦(A)core / (B)core≦5 Satisfy the relationship of <1> ~ <5> 1. The photosensitive resin composition set according to any one of claims 1 to 9. <7> When the non-volatile components of the clad resin composition are taken as 100% by mass, the contents of the (A) component and the (B) component in the clad resin composition are taken as (A)clad and (B)clad, respectively. 0.1≦(A)clad / (B)clad≦5 Satisfy the relationship of <1> ~ <6> 1. The photosensitive resin composition set according to any one of claims 1 to 9. <8> When the non-volatile components of the core resin composition are taken as 100% by mass, the contents of the (A) component and the (C) component in the core resin composition are taken as (A)core and (C)core, respectively, and the (A)core and the (C)core are 0.1≦(A)core / (C)core≦5 Satisfy the relationship of <1> ~ <7> 1. The photosensitive resin composition set according to any one of claims 1 to 9. <9> When the non-volatile components of the clad resin composition are taken as 100% by mass, the contents of the (A) component and the (C) component in the clad resin composition are taken as (A)clad and (C)clad, respectively. 0.1≦(A)clad / (C)clad≦5 Satisfy the relationship of <1> ~ <8> 1. The photosensitive resin composition set according to any one of claims 1 to 9. <10> The core resin composition and the clad resin composition each further contain (H) an organic solvent. <1> ~ <9> 1. The photosensitive resin composition set according to any one of claims 1 to 9. <11> A photosensitive resin composition set for producing an optical waveguide, <1> ~ <10> 1. The photosensitive resin composition set according to any one of claims 1 to 9. <12> A photosensitive resin composition set for producing an optical waveguide capable of transmitting light with a wavelength of 1300 nm to 1320 nm. <1> ~ <11> 1. The photosensitive resin composition set according to any one of claims 1 to 9. <13> A photosensitive resin composition set for producing a single-mode optical waveguide, <1> ~ <12> 1. The photosensitive resin composition set according to any one of claims 1 to 9. <14> A photosensitive resin sheet set including a core resin sheet and a clad resin sheet, The core resin sheet is <1> ~ <13> a resin composition layer containing the core resin composition in the photosensitive resin composition set according to any one of Cladding resin sheets <1> ~ <13> 10. A photosensitive resin sheet set comprising a resin composition layer containing the cladding resin composition in the photosensitive resin composition set according to any one of claims 1 to 9. <15> A photosensitive resin ink set including a core resin ink and a cladding resin ink, Core resin ink, <1> ~ <13> The core resin composition in the photosensitive resin composition set according to any one of Cladding resin ink <1> ~ <13> 10. A photosensitive resin ink set comprising the cladding resin composition in the photosensitive resin composition set according to any one of claims 1 to 9. <16> An optical waveguide having a core layer and a clad layer, The core layer, (A) a carboxyl group-containing resin (a1) or an epoxy group- and radically polymerizable group-containing resin (a2), (B) epoxy resin, (C) a photocurable resin, and (D) Photopolymerization initiator and (E) an alkoxysilane compound having one or more functional groups selected from the group consisting of an epoxy group, a phenylamino group, a vinyl group, and a (meth)acryloyl group; The core resin composition may contain a cured product of the core resin composition, The cladding layer is (A) a carboxyl group-containing resin (a1) or an epoxy group- and radically polymerizable group-containing resin (a2), (B) epoxy resin, (C) Photocurable resin, (D) a photoinitiator, and (E) an alkoxysilane compound having one or more functional groups selected from the group consisting of an epoxy group, a phenylamino group, a vinyl group, and a (meth)acryloyl group; The present invention relates to a cured product of a resin composition for cladding, When the nonvolatile components of the core resin composition are taken as 100% by mass, the content (% by mass) of the (E) component in the core resin composition is taken as (E)core, and when the nonvolatile components of the clad resin composition are taken as 100% by mass, the content (% by mass) of the (E) component in the clad resin composition is taken as (E)clad, (E)core and (E)clad are 0.6≦(E)clad-(E)core≦10 An optical waveguide that satisfies the relationship: <17> <16> An optical / electrical hybrid board comprising the optical waveguide according to claim 1. <18> forming a first composition layer containing a cladding resin composition; curing the first composition layer; forming a second composition layer containing a core resin composition on the first composition layer; a step of exposing the second composition layer to light; a step of subjecting the second composition layer to a development treatment; curing the second composition layer; forming a third composition layer containing a cladding resin composition on the second composition layer; and curing the third composition layer in this order, The core resin composition and the clad resin composition each comprise: (A) carboxyl group-containing resin (a1), (B) epoxy resin, (C) a photocurable resin, and (D) Photopolymerization initiator Including, At least the cladding resin composition further comprises (E) an alkoxysilane compound having one or more functional groups selected from the group consisting of an epoxy group, a phenylamino group, a vinyl group, and a (meth)acryloyl group; Including, When the nonvolatile components of the core resin composition are taken as 100% by mass, the content (% by mass) of the (E) component in the core resin composition is taken as (E)core, and when the nonvolatile components of the clad resin composition are taken as 100% by mass, the content (% by mass) of the (E) component in the clad resin composition is taken as (E)clad, (E)core and (E)clad are 0.6≦(E)clad-(E)core≦10 A method for manufacturing an optical waveguide that satisfies the relationship: <19> forming a first composition layer containing a cladding resin composition; curing the first composition layer; forming a second composition layer containing a core resin composition on the first composition layer; curing the second composition layer; forming a fourth composition layer containing a resist composition on the second composition layer; a step of exposing the fourth composition layer to light; a step of subjecting the fourth composition layer to a development treatment; forming a pattern in the second composition layer; forming a third composition layer containing a cladding resin composition on the second composition layer; and curing the third composition layer in this order, The core resin composition and the clad resin composition each comprise: (A) a resin (a2) containing an epoxy group and a radical polymerizable group, (B) epoxy resin, (C) a photocurable resin, and (D) Photopolymerization initiator Including, At least the cladding resin composition further comprises (E) an alkoxysilane compound having one or more functional groups selected from the group consisting of an epoxy group, a phenylamino group, a vinyl group, and a (meth)acryloyl group; Including, When the nonvolatile components of the core resin composition are taken as 100% by mass, the content (% by mass) of the (E) component in the core resin composition is taken as (E)core, and when the nonvolatile components of the clad resin composition are taken as 100% by mass, the content (% by mass) of the (E) component in the clad resin composition is taken as (E)clad, (E)core and (E)clad are 0.6≦(E)clad-(E)core≦10 A method for manufacturing an optical waveguide that satisfies the relationship: <20> forming a first composition layer containing a cladding resin composition; curing the first composition layer; forming a second composition layer containing a core resin composition on the first composition layer; a step of exposing the second composition layer to light; a step of subjecting the second composition layer to a development treatment; curing the second composition layer; forming a third composition layer containing a cladding resin composition on the second composition layer; and curing the third composition layer in this order, The core resin composition and the clad resin composition each comprise: (A) carboxyl group-containing resin (a1), (B) epoxy resin, (C) a photocurable resin, and (D) Photopolymerization initiator Including, At least the cladding resin composition further comprises (E) an alkoxysilane compound having one or more functional groups selected from the group consisting of an epoxy group, a phenylamino group, a vinyl group, and a (meth)acryloyl group; Including, When the nonvolatile components of the core resin composition are taken as 100% by mass, the content (% by mass) of the (E) component in the core resin composition is taken as (E)core, and when the nonvolatile components of the clad resin composition are taken as 100% by mass, the content (% by mass) of the (E) component in the clad resin composition is taken as (E)clad, (E)core and (E)clad are 0.6≦(E)clad-(E)core≦10 A method for manufacturing an optical / electrical hybrid board that satisfies the above relationship. <21> forming a first composition layer containing a cladding resin composition; curing the first composition layer; forming a second composition layer containing a core resin composition on the first composition layer; curing the second composition layer; forming a fourth composition layer containing a resist composition on the second composition layer; a step of exposing the fourth composition layer to light; a step of subjecting the fourth composition layer to a development treatment; forming a pattern in the second composition layer; forming a third composition layer containing a cladding resin composition on the second composition layer; and curing the third composition layer in this order, The core resin composition and the clad resin composition each comprise: (A) a resin (a2) containing an epoxy group and a radical polymerizable group, (B) epoxy resin, (C) a photocurable resin, and (D) Photopolymerization initiator Including, At least the cladding resin composition further comprises (E) an alkoxysilane compound having one or more functional groups selected from the group consisting of an epoxy group, a phenylamino group, a vinyl group, and a (meth)acryloyl group; Including, When the nonvolatile components of the core resin composition are taken as 100% by mass, the content (% by mass) of the (E) component in the core resin composition is taken as (E)core, and when the nonvolatile components of the clad resin composition are taken as 100% by mass, the content (% by mass) of the (E) component in the clad resin composition is taken as (E)clad, (E)core and (E)clad are 0.6≦(E)clad-(E)core≦10 A method for manufacturing an optical / electrical hybrid board that satisfies the above relationship. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a photosensitive resin composition set capable of producing a single-mode optical waveguide in which the change in optical transmission loss before and after a reliability test is small; a photosensitive resin sheet set; a photosensitive resin ink set; an optical waveguide; a method for producing the optical waveguide; an optical-electrical hybrid substrate including the optical waveguide; and a method for producing the optical-electrical hybrid substrate. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view schematically showing an optical waveguide according to one embodiment of the present invention. [Figure 2] FIG. 2 is a schematic cross-sectional view illustrating step (I) of the method for manufacturing an optical waveguide according to the first embodiment of the present invention. [Figure 3] FIG. 3 is a schematic cross-sectional view illustrating step (II) of the method for manufacturing an optical waveguide according to the first embodiment of the present invention. [Figure 4] FIG. 4 is a schematic cross-sectional view illustrating step (III) of the method for manufacturing an optical waveguide according to the first embodiment of the present invention. [Figure 5] FIG. 5 is a schematic cross-sectional view illustrating step (IV) of the method for manufacturing an optical waveguide according to the first embodiment of the present invention. [Figure 6] FIG. 6 is a schematic cross-sectional view illustrating step (V) of the method for manufacturing an optical waveguide according to the first embodiment of the present invention. [Figure 7]FIG. 7 is a schematic cross-sectional view illustrating step (VI) of the method for manufacturing an optical waveguide according to the first embodiment of the present invention. [Figure 8] FIG. 8 is a schematic cross-sectional view illustrating step (VII) of the method for manufacturing an optical waveguide according to the first embodiment of the present invention. [Figure 9] FIG. 9 is a schematic cross-sectional view illustrating step (VIII) of the method for manufacturing an optical waveguide according to the first embodiment of the present invention. [Figure 10] FIG. 10 is a schematic cross-sectional view illustrating step (IX) of the method for manufacturing an optical waveguide according to the first embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] <Terminology> In this specification, the term "organic group" refers to a group containing at least carbon atoms as skeletal atoms, 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 50, more preferably 1 to 30, and even more preferably 1 to 20 or 1 to 10. The number of skeletal atoms does not include the number of skeletal atoms of an epoxy group. Examples of organic groups include groups containing one or more skeletal atoms (including at least a carbon atom) selected from carbon, oxygen, nitrogen, sulfur, and silicon atoms.

[0011] As used herein, the term "aliphatic group" refers to a group in which one or more hydrogen atoms have been removed from an aliphatic compound. Specifically, an n-valent aliphatic group (where n is an integer of 1 or more; the same applies hereinafter) refers to a group in which n hydrogen atoms have been removed from an aliphatic compound. Here, the aliphatic compound may be a heteroatom-free aliphatic compound composed only of carbon and hydrogen atoms, or a heteroatom-containing aliphatic compound composed of carbon and hydrogen atoms as well as heteroatoms. As used herein, the term "heteroatom" refers to an atom other than carbon and hydrogen atoms, and examples thereof include oxygen atoms, nitrogen atoms, sulfur atoms, silicon atoms, and halogen atoms.

[0012] As used herein, the term "aliphatic hydrocarbon group" refers to a group obtained by removing one or more hydrogen atoms from an aliphatic compound that does not contain a heteroatom and is composed only of carbon atoms and hydrogen atoms. Specifically, an n-valent aliphatic hydrocarbon group refers to a group obtained by removing n hydrogen atoms from an aliphatic compound that does not contain a heteroatom. Examples of n-valent aliphatic hydrocarbon groups include groups obtained by removing n hydrogen atoms from an aliphatic compound selected from the group consisting of an optionally substituted alkane, an optionally substituted alkene, an optionally substituted alkyne, and an optionally substituted alkapolyene (each having preferably 2 to 10 double bonds, more preferably 2 to 6, even more preferably 2 to 4, and even more preferably 2). Here, any of the alkanes, alkenes, alkynes, and alkapolyenes may be linear or branched and may contain a cyclic structure. In this specification, the number of carbon atoms in the aliphatic hydrocarbon group is preferably 1 or more, more preferably 2 or more, or 3 or more, and preferably 100 or less, more preferably 80 or less, even more preferably 60 or less, 50 or less, or 40 or less, unless otherwise specified. The number of carbon atoms does not include the number of carbon atoms of the substituents.

[0013] As used herein, the term "heteroatom-containing aliphatic group" refers to a group obtained by removing one or more hydrogen atoms from an aliphatic compound containing a heteroatom. Specifically, an n-valent heteroatom-containing aliphatic group refers to a group obtained by removing n hydrogen atoms from an aliphatic compound containing a heteroatom. In the "heteroatom-containing aliphatic group" herein, the heteroatom may be bonded to any of the carbon atoms constituting the group, for example, (i) it may be bonded to a terminal carbon or (ii) it may be interposed between carbon-carbon bonds. Furthermore, in the "heteroatom-containing aliphatic group" herein, the bond may extend from either a carbon atom or a heteroatom. The heteroatom-containing aliphatic group may be either a saturated or unsaturated heteroatom-containing aliphatic group and may have a cyclic structure. Examples of n-valent heteroatom-containing aliphatic groups include groups obtained by removing n hydrogen atoms from an aliphatic compound containing a heteroatom selected from the group consisting of optionally substituted heteroalkanes, optionally substituted heteroalkenes, optionally substituted heteroalkynes, and optionally substituted heteroalkapolyenes. Here, the heteroalkane, heteroalkene, heteroalkyne, and heteroalkapolyene may be linear or branched, and may contain a cyclic structure. In the heteroatom-containing aliphatic group, the heteroatom is preferably one or more selected from the group consisting of oxygen, nitrogen, sulfur, and silicon atoms. For example, the heteroatom may exist as a heteroatom such as -O-, -S-, or -N<. Alternatively, the heteroatom may exist as a heteroatom-containing group such as -C(=O)-, -S(=O)-, -S(=O)2-, -N(R')-, -Si(R')2-, or a combination thereof, or a combination thereof with -O- or -S- (wherein R' represents a hydrogen atom or a substituent described below; the same applies hereinafter). When the heteroatom-containing aliphatic group contains two or more heteroatoms, the heteroatoms may be the same or different.In this specification, unless otherwise specified, the number of heteroatoms in a heteroatom-containing aliphatic group is preferably 1 or more, 2 or more, or 3 or more, and preferably 30 or less, 25 or less, or 20 or less, and the number of carbon atoms therein is preferably 1 or more, more preferably 2 or more or 3 or more, and preferably 100 or less, more preferably 80 or less, and even more preferably 60 or less, 50 or less, or 40 or less, unless otherwise specified. The number of heteroatoms and the number of carbon atoms do not include the number of heteroatoms and the number of carbon atoms of substituents.

[0014] As used herein, the term "aromatic group" refers to a group obtained by removing one or more hydrogen atoms from an aromatic compound. Specifically, an n-valent aromatic group refers to a group obtained by removing n hydrogen atoms from an aromatic compound. Here, the aromatic compound may be a heteroatom-free aromatic compound composed only of carbon and hydrogen atoms, or a heteroatom-containing aromatic compound composed of carbon atoms, hydrogen atoms, and heteroatoms. As used herein, the term "aromatic compound" refers to a compound containing an aromatic ring. Furthermore, as used herein, the term "aromatic ring" refers to a ring conforming to the Hückel rule, in which the number of electrons in the π-electron system of the ring is 4p+2 (p is a natural number), and includes monocyclic aromatic rings and fused polycyclic aromatic rings in which two or more monocyclic aromatic rings are fused together. The aromatic ring may be an aromatic carbocycle having only carbon atoms as ring-constituting atoms, or an aromatic heterocycle having carbon atoms and heteroatoms such as oxygen, nitrogen, or sulfur as ring-constituting atoms. In this specification, unless otherwise specified, the number of carbon atoms in the aromatic ring is preferably 3 or more, more preferably 4 or more or 5 or more, and even more preferably 6 or more, and the upper limit is preferably 24 or less, more preferably 18 or less or 14 or less, and even more preferably 10 or less. The number of carbon atoms does not include the number of carbon atoms of substituents.

[0015] As used herein, the term "aromatic hydrocarbon group" refers to a group obtained by removing one or more hydrogen atoms from a heteroatom-free aromatic compound composed only of carbon atoms and hydrogen atoms. Specifically, an n-valent aromatic hydrocarbon group refers to a group obtained by removing n hydrogen atoms from a heteroatom-free aromatic compound. As used herein, unless otherwise specified, the number of carbon atoms in an aromatic hydrocarbon group is preferably 6 or more, and preferably 100 or less, more preferably 80 or less, and even more preferably 60 or less, 50 or less, or 40 or less. The number of carbon atoms does not include the number of carbon atoms of substituents.

[0016] As used herein, the term "heteroatom-containing aromatic group" refers to a group obtained by removing one or more hydrogen atoms from an aromatic compound containing a heteroatom. Specifically, an n-valent heteroatom-containing aromatic group refers to a group obtained by removing n hydrogen atoms from an aromatic compound containing a heteroatom. In the "heteroatom-containing aromatic group" herein, the heteroatom may be bonded to any of the carbon atoms constituting the group, for example, (i) it may be bonded to a terminal carbon, or (ii) it may be interposed between carbon-carbon bonds. Furthermore, in the "heteroatom-containing aromatic group" herein, the bond may extend from either a carbon atom or a heteroatom. Examples of n-valent heteroatom-containing aromatic groups include groups obtained by removing n hydrogen atoms from an optionally substituted heteroaryl compound. In this specification, unless otherwise specified, the number of heteroatoms in a heteroatom-containing aromatic group is preferably 1 or more, 2 or more, or 3 or more, and preferably 30 or less, 25 or less, or 20 or less, and the number of carbon atoms therein is preferably 3 or more, 4 or more, 5 or more, or 6 or more, and preferably 100 or less, more preferably 80 or less, and even more preferably 60 or less, 50 or less, or 40 or less. The number of heteroatoms and the number of carbon atoms therein do not include the number of heteroatoms and the number of carbon atoms of substituents.

[0017] As used herein, the term "optionally substituted" in reference to a compound or group means both a case where the hydrogen atoms of the compound or group are not substituted with substituents, and a case where some or all of the hydrogen atoms of the compound or group are substituted with substituents.

[0018] In this specification, unless otherwise specified, the term "substituent" means a halogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkapolyenyl group, a cycloalkyl group, a cycloalkenyl group, an alkoxy group, an alkenyloxy group, a cycloalkyloxy group, a cycloalkenyloxy group, an alkylthio group, a cycloalkylthio group, an aryl group, an aryloxy group, an arylthio group, an arylalkyl group, an arylalkoxy group, a monovalent aliphatic heterocyclic group, an alkylidene group, an acyl group, an acyloxy group, an amino group, a silyl group, a carboxyl group, a sulfo group, a cyano group, a nitro group, a mercapto group, or an oxo group.

[0019] Examples of halogen atoms used as substituents include fluorine, chlorine, bromine, and iodine atoms. The alkyl group used as a substituent may be either linear or branched. The alkyl group preferably has 1 to 12 carbon atoms, more preferably 1 to 6, and even more preferably 1 to 4. The alkenyl group or alkynyl group used as a substituent may be either linear or branched. The alkenyl group or alkynyl group preferably has 2 to 12 carbon atoms, more preferably 2 to 6, and even more preferably 2 to 4 carbon atoms. The alkapolyenyl group used as a substituent may be either linear or branched, and the number of double bonds is preferably 2 to 10, more preferably 2 to 6, even more preferably 2 to 4, and even more preferably 2. The alkapolyenyl group preferably has 3 to 20 carbon atoms, more preferably 3 to 14, even more preferably 3 to 12, and even more preferably 3 to 6. The cycloalkyl group or cycloalkenyl group used as a substituent preferably has 3 to 12 carbon atoms, more preferably 3 to 6. The alkoxy group used as a substituent may be either linear or branched. The alkoxy group preferably has 1 to 12 carbon atoms, more preferably 1 to 6. The alkenyloxy group used as a substituent may be either linear or branched. The alkenyloxy group preferably has 2 to 12 carbon atoms, more preferably 2 to 6, and even more preferably 2 to 4. The cycloalkyloxy group or cycloalkenyloxy group used as a substituent preferably has 3 to 12 carbon atoms, more preferably 3 to 6. The alkylthio group used as a substituent may be either linear or branched. The alkylthio group preferably has 1 to 12 carbon atoms, more preferably 1 to 6. The cycloalkylthio group used as a substituent preferably has 3 to 12 carbon atoms, more preferably 3 to 6. The aryl group used as a substituent preferably has 6 to 14 carbon atoms, more preferably 6 to 10. The aryloxy group used as a substituent preferably has 6 to 14 carbon atoms, more preferably 6 to 10.The number of carbon atoms of the arylthio group used as a substituent is preferably 6 to 14, more preferably 6 to 10. The number of carbon atoms of the arylalkyl group used as a substituent is preferably 7 to 15, more preferably 7 to 11. The number of carbon atoms of the arylalkoxy group used as a substituent is preferably 7 to 15, more preferably 7 to 11. The monovalent aliphatic heterocyclic group used as a substituent means a group obtained by removing one hydrogen atom from an aliphatic heterocyclic compound. The number of carbon atoms of the monovalent aliphatic heterocyclic group is preferably 3 to 15, more preferably 3 to 9. The alkylidene group used as a substituent means a group obtained by removing two hydrogen atoms from the same carbon atom of an alkane. The number of carbon atoms of the alkylidene group is preferably 1 to 12, more preferably 1 to 6, particularly preferably 1 to 4. The acyl group used as a substituent is a group represented by the formula: -C(=O)-R. (In the formula, R S is an alkyl group). R S The alkyl group represented by may be either linear or branched. The number of carbon atoms of the acyl group is preferably 2 to 13, more preferably 2 to 7. The acyloxy group used as a substituent is a group represented by the formula: -O-C(=O)-R S (In the formula, R S has the same meaning as above). The number of carbon atoms of the acyloxy group is preferably 2 to 13, more preferably 2 to 7. The above-mentioned substituents may further have substituents (sometimes referred to as "secondary substituents"). As the secondary substituents, the same ones as the above-mentioned substituents may be used unless otherwise specified.

[0020] In this specification, the term "C p ~C q " (where p and q are positive integers and p < q) represents that the number of carbon atoms of the organic group described immediately after this term is p to q. For example, "C1~C6 alkyl group" indicates an alkyl group having 1 to 6 carbon atoms, and "C6~C 10 cycloalkyl group" indicates a cycloalkyl group having 6 to 10 carbon atoms. <​​As used herein, the term "(meth)acrylic acid" includes acrylic acid, methacrylic acid, and combinations thereof; the term "(meth)acryloyl group" includes acryloyl group, methacryloyl group, and combinations thereof; and the term "(meth)acrylate" includes acrylate, methacrylate, and combinations thereof.

[0022] The present invention will be described in detail below with reference to embodiments and examples. However, the present invention is not limited to the following embodiments and examples, and can be implemented with any modifications within the scope of the claims of the present invention and their equivalents.

[0023] [Photosensitive resin composition set] The photosensitive resin composition set of the present invention includes a core resin composition and a clad resin composition. The core resin composition can be suitably used as a photosensitive resin composition for forming a core layer of an optical waveguide, and the clad resin composition can be suitably used as a photosensitive resin composition for forming a clad layer of an optical waveguide. The photosensitive resin composition set of the present invention can be used for producing an optical waveguide having a core layer containing a cured product of the core resin composition and a clad layer containing a cured product of the clad resin composition.

[0024] In the photosensitive resin composition set of the present invention, The core resin composition and the clad resin composition are each (A) a carboxyl group-containing resin (a1) or an epoxy group- and radically polymerizable group-containing resin (a2), (B) epoxy resin, (C) a photocurable resin, and (D) Photopolymerization initiator Including, At least the cladding resin composition further contains (E) an alkoxysilane compound having one or more functional groups selected from the group consisting of an epoxy group, a phenylamino group, a vinyl group, and a (meth)acryloyl group.

[0025] The photosensitive resin composition set of the present invention is characterized in that (E)core and (E)clad satisfy the relationship 0.6≦(E)clad-(E)core≦10, where (E)core is the content (% by mass) of component (E) in the core resin composition when the non-volatile components of the core resin composition are taken as 100% by mass, and (E)clad is the content (% by mass) of component (E) in the clad resin composition when the non-volatile components of the clad resin composition are taken as 100% by mass.

[0026] The photosensitive resin composition set of the present invention can produce a single-mode optical waveguide in which the change in optical transmission loss before and after a reliability test is small. The photosensitive resin composition set of the present invention can also produce an optical waveguide in which the optical transmission loss value is small even after a reliability test. Furthermore, the photosensitive resin composition set of the present invention can usually achieve good thin-wire waveguide formation.

[0027] As described above, the core resin composition and the clad resin composition each contain (A) a carboxyl group-containing resin (a1) or an epoxy group- and radically polymerizable group-containing resin (a2), (B) an epoxy resin, (C) a photocurable resin, and (D) a photopolymerization initiator. At least the clad resin composition further contains (E) an alkoxysilane compound having one or more functional groups selected from the group consisting of an epoxy group, a phenylamino group, a vinyl group, and a (meth)acryloyl group. The core resin composition and the clad resin composition each contain the respective components so that the relationship 0.6≦(E)clad−(E)core≦10 is satisfied. The core and clad resin compositions may each further contain optional components such as (F) a curing accelerator, (G) other additives, and (H) an organic solvent, as needed. Hereinafter, the core resin composition and the clad resin composition may be collectively referred to as the “resin composition.”

[0028] <(A) Carboxyl Group-Containing Resin (a1) or Epoxy Group- and Radical Polymerizable Group-Containing Resin (a2)> In the photosensitive resin composition set of the present invention, the resin composition contains, as component (A), a carboxyl group-containing resin (a1) or an epoxy group- and radically polymerizable group-containing resin (a2).

[0029] In this specification, the carboxyl group-containing resin (a1) as component (A) is also referred to simply as "resin (a1)" or "component (a1)," and the epoxy group- and radically polymerizable group-containing resin (a2) as component (A) is also referred to simply as "resin (a2)" or "component (a2)."

[0030] -Carboxyl group-containing resin (a1)- In one embodiment, the resin composition in the photosensitive resin composition set of the present invention contains a carboxyl group-containing resin (a1) as component (A). The component (a1) may be used alone or in combination of two or more.

[0031] The resin composition containing the component (a1) is soluble in an alkaline developer (e.g., a 1% by mass aqueous solution of sodium carbonate) and can be developed in an alkaline solution. The number of carboxyl groups per molecule of the component (a1) may be one or more.

[0032] Although there are no limitations on the component (a1) as long as it is alkali developable, it is preferable that the component (a1) further contains a radically polymerizable group. Examples of the radically polymerizable group include unsaturated hydrocarbon groups such as vinyl, allyl, 1-propenyl, 3-cyclohexenyl, 3-cyclopentenyl, 2-vinylphenyl, 3-vinylphenyl, and 4-vinylphenyl; and α,β-unsaturated carbonyl groups such as (meth)acryloyl and maleimide groups (2,5-dihydro-2,5-dioxo-1H-pyrrol-1-yl).

[0033] When component (a1) contains a radical polymerizable group, photoradical polymerization is possible. In particular, component (a1) preferably contains a (meth)acryloyl group from the viewpoint of photoradical polymerization reactivity. The number of radical polymerizable groups per molecule of component (a1) may be one or two or more. Furthermore, when component (a1) contains two or more radical polymerizable groups per molecule, these radical polymerizable groups may be the same or different.

[0034] The component (a1) is preferably a resin that has both a radically polymerizable group and a carboxyl group, and that allows for photoradical polymerization and alkaline development.

[0035] In one embodiment, component (a1) preferably contains an aromatic skeleton. Here, the term "aromatic skeleton" refers to a skeleton containing an aromatic group, and the aromatic group is as described above. In particular, from the viewpoint of being able to further enjoy the effects of the present invention, it is more preferable that component (a1) contains one or more aromatic skeletons selected from an aralkyl skeleton and a cardo skeleton. That is, in one embodiment, component (a1) contains one or more of an aralkyl resin and a cardo resin.

[0036] Examples of the aralkyl skeleton include a naphthol aralkyl skeleton, a phenol aralkyl skeleton, and a biphenyl aralkyl skeleton. Among these, a naphthol aralkyl skeleton is preferred from the viewpoint of further enjoying the effects of the present invention. Therefore, in one embodiment, the component (a1) contains a naphthol aralkyl resin as the aralkyl resin.

[0037] The cardo skeleton is a ring structure A 1 Two ring structures A are attached to one carbon atom that constitutes 2 , and A 3 refers to a skeleton in which

[0038] [ka]

[0039] (In formula (A1), Ring structure A 1 represents one or more cyclic structures selected from the group consisting of an aliphatic ring and an aliphatic ring condensed with an aromatic ring; Ring structure A 2 and A 3 each independently represents one or more cyclic structures selected from the group consisting of an aliphatic ring, an aromatic ring, and an aliphatic ring condensed with an aromatic ring.

[0040] In formula (A1), the cyclic structure A 1 represents one or more cyclic structures selected from the group consisting of an aliphatic ring and an aliphatic ring condensed with an aromatic ring. 1 may have a substituent. The aliphatic ring may be an aliphatic carbon ring or an aliphatic hetero ring.

[0041] Examples of the alicyclic ring include monocycloalkanes such as cyclopentane, cyclohexane, cycloheptane, and cyclooctane; bicycloalkanes such as adamantane, norbornane, and isobornane; tricycloalkanes such as tricyclodecane; and tetracycloalkanes such as tetracyclodecane.

[0042] Examples of the aliphatic ring condensed with an aromatic ring include a fluorene ring and structures similar thereto. The similar structures include a skeleton in which at least one of the two benzene rings in the fluorene ring is replaced with a naphthalene ring or the like, a structure in which one of the two benzene rings in the fluorene ring is removed, a structure in which the number of carbon atoms in the five-membered carbon ring in the fluorene ring is changed, and combinations thereof, and also include those having a substituent.

[0043] In formula (A1), the cyclic structure A 2 and A 3 each independently represents one or more cyclic structures selected from the group consisting of an aliphatic ring, an aromatic ring, and an aliphatic ring condensed with an aromatic ring. 2 and A 3 The cyclic structure A may have a substituent. 2 and A 3is an aliphatic ring or an aliphatic ring condensed with an aromatic ring, the cyclic structure thereof is 1 The same range of structures as those listed above can be mentioned. 2 and A 3 are each independently preferably an aromatic ring, more preferably an aromatic ring having 6 to 14 carbon atoms, further preferably an aromatic ring having 6 to 10 carbon atoms (for example, a benzene ring or a naphthalene ring), and even more preferably a benzene ring.

[0044] Ring structure A in the cardo skeleton 1 , A 2 and A 3 The substituents that may be possessed by are as described above, and among them, one or more selected from the group consisting of a halogen atom, an alkyl group, an alkoxy group, and an aryl group are preferred, and one or more selected from the group consisting of a fluorine atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, and an aryl group having 6 to 14 carbon atoms are more preferred.

[0045] When component (a1) contains a cardo skeleton (i.e., contains a cardo type resin), the cardo skeleton is preferably a divalent group represented by the following formulas (A2-1) to (A2-3), and more preferably a divalent group represented by formula (A2-1), where * indicates a bonding site.

[0046] [ka]

[0047] In a preferred embodiment, the component (a1) includes an acid-modified epoxy (meth)acrylate resin.

[0048] The acid-modified epoxy(meth)acrylate resin can be produced by acid-modifying an epoxy(meth)acrylate resin by a known method, for example, by reacting an epoxy resin with (meth)acrylic acid.

[0049] The epoxy resin for producing the epoxy (meth)acrylate resin is not particularly limited as long as it is a compound having an epoxy group in the molecule, and examples thereof include bisphenol-type epoxy resins such as bisphenol A-type epoxy resin, hydrogenated bisphenol A-type epoxy resin, bisphenol F-type epoxy resin, hydrogenated bisphenol F-type epoxy resin, bisphenol S-type epoxy resin, and modified bisphenol F-type epoxy resin obtained by reacting bisphenol F-type epoxy resin with epichlorohydrin to modify it to have three or more functionalities; biphenol-type epoxy resins such as biphenol-type epoxy resin and tetramethylbiphenol-type epoxy resin; novolac-type epoxy resins such as phenol novolac-type epoxy resin, cresol novolac-type epoxy resin, bisphenol A-type novolac-type epoxy resin, and alkylphenol novolac-type epoxy resin; fluorine-containing epoxy resins such as bisphenol AF-type epoxy resin and perfluoroalkyl-type epoxy resin; naphthalene-type epoxy resin, dihydroxynaphthalene-type epoxy resin, polyhydroxybinaphthalene-type epoxy resin, naphthol-type epoxy resin, naphtholaralkyl-type epoxy resin Epoxy resins with a naphthalene skeleton (epoxy resins containing a naphthalene skeleton), such as epoxide resins, binaphthol-type epoxy resins, naphthylene ether-type epoxy resins, naphthol novolac-type epoxy resins, and naphthalene-type epoxy resins obtained by the condensation reaction of polyhydroxynaphthalene with aldehydes; bixylenol-type epoxy resins; dicyclopentadiene-type epoxy resins; trisphenol-type epoxy resins; tert-butyl-catechol-type epoxy resins; epoxy resins containing a condensed ring skeleton, such as anthracene-type epoxy resins; glycidylamine Type epoxy resins;Glycidyl ester type epoxy resins;Biphenyl type epoxy resins;Linear aliphatic epoxy resins;Epoxy resins containing butadiene structure;Alicyclic epoxy resins;Heterocyclic epoxy resins;Spiro ring-containing epoxy resins;Cyclohexanedimethanol type epoxy resins;Trimethylol type epoxy resins;Tetraphenylethane type epoxy resins;Glycidyl group-containing acrylic resins such as polyglycidyl (meth)acrylate and copolymers of glycidyl methacrylate and acrylic ester;Fluorene type epoxy resins;Epoxy resins containing cardo skeleton;Halogenated epoxy resins, etc.;

[0050] The epoxy resin for producing the epoxy (meth)acrylate resin preferably contains an aromatic skeleton. The aromatic skeleton is as described above, and among them, one or more selected from an aralkyl skeleton and a cardo skeleton are preferred. Therefore, in one embodiment, the epoxy resin for producing the epoxy (meth)acrylate resin contains one or more selected from the group consisting of an aralkyl skeleton-containing epoxy resin (preferably a naphthol aralkyl epoxy resin) and a cardo skeleton-containing epoxy resin.

[0051] In one embodiment, the acid-modified epoxy(meth)acrylate resin preferably contains a resin selected from an acid-modified epoxy(meth)acrylate resin in which a hydroxyl group of an epoxy(meth)acrylate resin has been esterified (hereinafter also referred to as an "ester-type acid-modified epoxy(meth)acrylate resin"), and an acid-modified epoxy(meth)acrylate resin in which a hydroxyl group of an epoxy(meth)acrylate resin has been urethanized (hereinafter also referred to as a "urethane-type acid-modified epoxy(meth)acrylate resin"), and more preferably contains an ester-type acid-modified epoxy(meth)acrylate resin.

[0052] The ester-type acid-modified epoxy(meth)acrylate resin can be produced, for example, by reacting an epoxy(meth)acrylate resin with an acid anhydride. The ester-type acid-modified epoxy(meth)acrylate resin may be used alone or in combination of two or more.

[0053] Examples of acid anhydrides include maleic anhydride, succinic anhydride, itaconic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, trimellitic anhydride, pyromellitic anhydride, and benzophenonetetracarboxylic dianhydride, and these may be used alone or in combination of two or more. Among these, succinic anhydride and tetrahydrophthalic anhydride are preferred, and tetrahydrophthalic anhydride is more preferred.

[0054] The acid-modified epoxy (meth)acrylate resin can be synthesized by a known method, but commercially available products may also be used. Specific examples of commercially available products include "CCR-1373H" (cresol novolac skeleton-containing acid-modified epoxy acrylate), "ZCR-8001H" (biphenyl skeleton-containing acid-modified epoxy acrylate), "ZCR-1569H" (biphenyl skeleton-containing acid-modified epoxy acrylate), "CCR-1171H" (cresol novolac skeleton-containing acid-modified epoxy acrylate), and "ZCR-1797H" (biphenyl skeleton-containing acid-modified epoxy acrylate), all manufactured by Nippon Kayaku Co., Ltd., and "ZAR-2000" (bisphenol A skeleton-containing acid-modified epoxy acrylate resin), "ZFR-1491H," and "ZFR-1533H" (bisphenol F skeleton-containing acid-modified epoxy acrylate), all manufactured by Nippon Kayaku Co., Ltd. resin), "PR-300CP" (cresol novolac-type acid-modified epoxy acrylate resin) manufactured by Showa Denko K.K., "CCR-1179" (cresol novolac skeleton-containing epoxy acrylate resin) manufactured by Nippon Kayaku Co., Ltd., "WR-301" (cardo skeleton-containing acid-modified epoxy acrylate) manufactured by ADEKA Corporation, "V-259ME" (cardo skeleton-containing acid-modified epoxy acrylate) manufactured by Nippon Steel Chemical & Material Co., Ltd., and "Oxol CR-TR1," "Oxol CR-TR2," "Oxol CR-TR3," "Oxol CR-TR4," "Oxol CR-TR5," and "Oxol CR-TR6" (cardo skeleton-containing acid-modified epoxy acrylates) manufactured by Osaka Gas Chemicals Co., Ltd. These may be used alone or in combination of two or more.

[0055] The urethane-type acid-modified epoxy(meth)acrylate resin can be produced, for example, by reacting an epoxy(meth)acrylate resin with a diisocyanate compound and a carboxyl group-containing diol compound. The urethane-type acid-modified epoxy(meth)acrylate resin may be used alone or in combination of two or more.

[0056] Examples of diisocyanate compounds include aromatic diisocyanate compounds such as phenylene diisocyanate, tolylene diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, diphenyl diisocyanate, and naphthalene diisocyanate; and aliphatic diisocyanate compounds such as hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, isophorone diisocyanate, allylene sulfone ether diisocyanate, allyl diisocyanate, N-acyl diisocyanate, trimethylhexamethylene diisocyanate, and 1,3-bis(isocyanatemethyl)cyclohexane.

[0057] Examples of the carboxy group-containing diol compound include dimethylolpropionic acid, dimethylolbutanoic acid, and dimethylolnonanoic acid.

[0058] The urethane-type acid-modified epoxy (meth)acrylate resin can be synthesized by a known synthesis method, but a commercially available product may also be used. Examples of known synthesis methods include the method described in JP 2016-199719 A. Specific examples of commercially available products include "UXE-3024," "UXE-3011," "UXE-3012," and "UXE-3024" manufactured by Nippon Kayaku Co., Ltd.

[0059] From the viewpoint of improving the alkali developability of the resin composition, the acid value of component (a1) is preferably 0.1 mgKOH / g or more, more preferably 0.5 mgKOH / g or more, even more preferably 1 mgKOH / g or more, 10 mgKOH / g or more, still more preferably 20 mgKOH / g or more, 30 mgKOH / g or more, 40 mgKOH / g or more, or 50 mgKOH / g or more. From the viewpoint of improving insulation reliability, the upper limit of the acid value of component (a1) is preferably 200 mgKOH / g or less, more preferably 150 mgKOH / g or less, even more preferably 120 mgKOH / g or less, or 100 mgKOH / g or less.

[0060] The weight average molecular weight (Mw) of component (a1) is preferably at least 500, more preferably at least 750, and even more preferably at least 900. The upper limit of Mw of component (a1) is preferably at most 20,000, more preferably at most 15,000, and even more preferably at most 10,000, 8,000, 6,000, or 5,000. The weight average molecular weight (Mw) is the weight average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC).

[0061] -Epoxy group and radical polymerizable group-containing resin (a2)- In one embodiment, the resin composition in the photosensitive resin composition set of the present invention contains, as component (A), an epoxy group- and radically polymerizable group-containing resin (a2). The component (a2) may be used alone or in combination of two or more.

[0062] The component (a2) does not include components that fall under the category of the component (a1) above. For example, in relation to the component (a1), the component (a2) does not need to contain a carboxyl group.

[0063] Component (a2) has both an epoxy group and a radically polymerizable group, and is thermosetting and capable of photoradical polymerization. Therefore, a resin composition containing component (a2) exhibits both thermosetting and photocuring properties.

[0064] The number of epoxy groups per molecule of component (a2) may be one or may be two or more.

[0065] The number of radically polymerizable groups per molecule of component (a2) may be one or more. Examples of radically polymerizable groups include unsaturated hydrocarbon groups such as vinyl, allyl, 1-propenyl, 3-cyclohexenyl, 3-cyclopentenyl, 2-vinylphenyl, 3-vinylphenyl, and 4-vinylphenyl; and α,β-unsaturated carbonyl groups such as (meth)acryloyl and maleimide groups (2,5-dihydro-2,5-dioxo-1H-pyrrol-1-yl). When component (a2) contains two or more radically polymerizable groups per molecule, these radically polymerizable groups may be the same or different.

[0066] In particular, the component (a2) preferably contains a (meth)acryloyl group from the viewpoint of reactivity in photoradical polymerization.

[0067] In component (a2), the remaining structure excluding the epoxy group and the radically polymerizable group (hereinafter also referred to as "residue") is not particularly limited as long as it is an organic group. For example, in component (a2) having a total of n epoxy groups and radically polymerizable groups, the residue is an n-valent organic group. As described above, the organic group may be either an aliphatic group or an aromatic group, but from the viewpoint of being able to enjoy the effects of the present invention more effectively, it is preferably an aromatic group, and more preferably a heteroatom-containing aromatic group. The aromatic group is as described above, but from the viewpoint of being able to enjoy the effects of the present invention more effectively, the aromatic ring contained in the aromatic group is preferably an aromatic carbon ring, more preferably an aromatic carbon ring having 6 to 14 carbon atoms (preferably 6 to 10), and the number of carbon atoms in the aromatic group is preferably 10 or more, more preferably 12 or more, 14 or more, 16 or more, or 18 or more, and the upper limit of the number of carbon atoms is preferably 50 or less, more preferably 40 or less, or 30 or less. When the aromatic group is a heteroatom-containing aromatic group, the heteroatom-containing aromatic group is as described above, but from the viewpoint of being able to enjoy the effects of the present invention more effectively, it preferably contains a heteroatom selected from an oxygen atom and a nitrogen atom, more preferably contains a heteroatom as -O-, -N<, -C(=O)-, or a combination thereof, and even more preferably contains a heteroatom as -O-, -C(=O)-, or a combination thereof. The number of heteroatoms in the heteroatom-containing aromatic group is as described above, but is preferably 2 or more or 3 or more, and the upper limit is preferably 10 or less, 8 or less, or 6 or less.

[0068] In particular, from the viewpoint of being able to enjoy the effects of the present invention more effectively, component (a2) preferably contains one or more aromatic skeletons selected from a bisphenol skeleton, a biphenyl skeleton, a naphthalene skeleton, an aralkyl skeleton, and a cardo skeleton, and more preferably contains one or more aromatic skeletons selected from a bisphenol skeleton, a biphenyl skeleton, and a naphthalene skeleton. Here, the bisphenol skeleton refers to a structure obtained by removing n hydrogen atoms (n is an integer of 2 or more) from various bisphenols such as bisphenol A, bisphenol F, bisphenol AP, bisphenol B, bisphenol C, and bisphenol P. The aralkyl skeleton and cardo skeleton, including preferred examples thereof, are as described for component (a1).

[0069] Component (a2) according to a preferred embodiment, which has a (meth)acryloyl group as the radical polymerizable group, can be produced by reacting an epoxy resin with (meth)acrylic acid. The raw material epoxy resin is as described for component (a1), and may be appropriately selected so as to provide the above-mentioned preferred residues and skeleton.

[0070] Component (a2) can be synthesized by a known method, but commercially available products may also be used, such as "EBECRYL3605" (bisphenol A type epoxy half acrylate) manufactured by Daicel-Allnex Corporation.

[0071] The epoxy equivalent of component (a2) is preferably 100 g / eq. or more, more preferably 200 g / eq. or more, 300 g / eq. or more, or 400 g / eq. or more, with the upper limit preferably being 2,000 g / eq. or less, 1,500 g / eq. or less, or 1,000 g / eq. or less. The epoxy equivalent is the mass of resin (a2) per equivalent of epoxy groups. This epoxy equivalent can be measured according to JIS K7236.

[0072] As described above, in the photosensitive resin composition set of the present invention, the resin composition contains component (a1) or component (a2) as component (A). The resin composition may contain a combination of component (a1) and component (a2), but preferably contains either component (a1) or component (a2). For example, the photosensitive resin composition set of the present invention may contain a core resin composition containing component (a1) as component (A) and a clad resin composition containing component (a1) as component (A), or may contain a core resin composition containing component (a2) as component (A) and a clad resin composition containing component (a2) as component (A). Alternatively, the photosensitive resin composition set of the present invention may include a core resin composition containing the component (a1) as the component (A) and a clad resin composition containing the component (a2) as the component (A); or may include a core resin composition containing the component (a2) as the component (A) and a clad resin composition containing the component (a1) as the component (A).

[0073] In the photosensitive resin composition set of the present invention, the content of component (A) in the resin composition is not particularly limited, but is preferably 10% by mass or more, more preferably 15% by mass or more, even more preferably 16% by mass or more, 18% by mass or more, or 20% by mass or more, when the non-volatile components in the resin composition are taken as 100% by mass, and the upper limit is preferably 60% by mass or less, more preferably 50% by mass or less, even more preferably 45% by mass or less, 44% by mass or less, 42% by mass or less, or 40% by mass or less.

[0074] In the present invention, the content of each component in the core resin composition is a value when the nonvolatile components in the core resin composition are taken as 100% by mass, unless otherwise specified, and the content of each component in the clad resin composition is a value when the nonvolatile components in the clad resin composition are taken as 100% by mass, unless otherwise specified. The nonvolatile components refer to all nonvolatile components in the resin composition excluding the solvent.

[0075] <(B) Epoxy resin> In the photosensitive resin composition set of the present invention, the resin composition contains an epoxy resin as component (B). Component (B) may be used alone or in combination of two or more. Note that component (B) does not include those corresponding to component (A) above.

[0076] Examples of component (B) include bisphenol-type epoxy resins, dicyclopentadiene-type epoxy resins, trisphenol-type epoxy resins, naphthol novolac-type epoxy resins, phenol novolac-type epoxy resins, tert-butyl-catechol-type epoxy resins, naphthalene-type epoxy resins, naphthol-type epoxy resins, anthracene-type epoxy resins, glycidylamine-type epoxy resins, glycidyl ester-type epoxy resins, cresol novolac-type epoxy resins, biphenyl-type epoxy resins, linear aliphatic epoxy resins, epoxy resins having a butadiene structure, alicyclic epoxy resins, heterocyclic epoxy resins, spiro ring-containing epoxy resins, cyclohexane-type epoxy resins, cyclohexanedimethanol-type epoxy resins, naphthylene ether-type epoxy resins, trimethylol-type epoxy resins, and tetraphenylethane-type epoxy resins. Bisphenol-type epoxy resins refer to epoxy resins having a bisphenol structure, such as bisphenol A-type epoxy resins, bisphenol F-type epoxy resins, bisphenol S-type epoxy resins, and bisphenol AF-type epoxy resins. Biphenyl-type epoxy resin refers to an epoxy resin having a biphenyl structure, where the biphenyl structure may have a substituent such as an alkyl group, an alkoxy group, an aryl group, etc. Therefore, bixylenol-type epoxy resins and biphenylaralkyl-type epoxy resins are also included in biphenyl-type epoxy resins.

[0077] Component (B) preferably contains an epoxy resin having two or more epoxy groups per molecule, and the proportion of the epoxy resin having two or more epoxy groups per molecule relative to 100% by mass of component (B) is preferably 50% by mass or more, more preferably 60% by mass or more, and even more preferably 70% by mass or more.

[0078] Component (B) includes epoxy resins that are liquid at a temperature of 20°C (hereinafter sometimes referred to as "liquid epoxy resins") and epoxy resins that are solid at a temperature of 20°C (hereinafter sometimes referred to as "solid epoxy resins"). In the photosensitive resin composition set of the present invention, the resin composition may contain only a liquid epoxy resin as component (B), or only a solid epoxy resin, or may contain both a liquid epoxy resin and a solid epoxy resin, but it is preferable that the resin composition contain only a solid epoxy resin or both a liquid epoxy resin and a solid epoxy resin.

[0079] The liquid epoxy resin is preferably a liquid epoxy resin having two or more epoxy groups in one molecule.

[0080] Preferred liquid epoxy resins include glycerol-type epoxy resins, bisphenol A-type epoxy resins, bisphenol F-type epoxy resins, bisphenol AF-type epoxy resins, naphthalene-type epoxy resins, glycidyl ester-type epoxy resins, glycidyl amine-type epoxy resins, phenol novolac-type epoxy resins, alicyclic epoxy resins having an ester skeleton, cyclohexanedimethanol-type epoxy resins, alicyclic glycidyl ethers, and epoxy resins having a butadiene structure.

[0081] Specific examples of liquid epoxy resins include "EX-992L" manufactured by Nagase ChemteX Corporation, "YX7400" manufactured by Mitsubishi Chemical Corporation, "HP4032", "HP4032D", and "HP4032SS" (naphthalene-type epoxy resins) manufactured by DIC Corporation; "828US", "jER828EL", "828EL", "825", and "Epikote 828EL" manufactured by Mitsubishi Chemical Corporation, "850" (bisphenol A-type epoxy resins) manufactured by DIC Corporation; and "jER807" and "1750" (bisphenol F-type epoxy resins) manufactured by Mitsubishi Chemical Corporation. Resin); Mitsubishi Chemical Corporation's "jER152" (phenol novolac type epoxy resin); DIC Corporation's "HP820" (alkylphenol type epoxy resin); Mitsubishi Chemical Corporation's "630", "630LSD", and "604" (glycidylamine type epoxy resin); ADEKA Corporation's "ED-523T" (glycirol type epoxy resin); ADEKA Corporation's "EP-3950L" and "EP-3980S" (glycidylamine type epoxy resin); ADEKA Corporation's "EP-4088S" (dicyclopentadiene type epoxy resin); "ZX1059" manufactured by Nippon Steel Chemical & Material Co., Ltd. (a mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin); "EX-721" manufactured by Nagase ChemteX Corporation (glycidyl ester type epoxy resin); "EX-991L" manufactured by Nagase ChemteX Corporation (an epoxy resin containing alkyleneoxy and butadiene skeletons); "Celloxide 2021P" manufactured by Daicel Corporation (alicyclic epoxy resin with an ester skeleton); "PB-3600" manufactured by Daicel Corporation, "JP" manufactured by Nippon Soda Co., Ltd. -100" and "JP-200" (epoxy resins having a butadiene structure); "ZX1658" and "ZX1658GS" (liquid 1,4-glycidylcyclohexane type epoxy resins) manufactured by Nippon Steel Chemical & Material Co., Ltd.; "EG-280" (fluorene structure-containing epoxy resins) manufactured by Osaka Gas Chemicals Co., Ltd.; "Oxol EG-200" and "Oxol EG-280" (cardo structure-containing epoxy resins) manufactured by Osaka Gas Chemicals Co., Ltd.; and "EX-201" (cyclic aliphatic glycidyl ether) manufactured by Nagase ChemteX Corporation.

[0082] As the solid epoxy resin, a solid epoxy resin having three or more epoxy groups in one molecule is preferred, and an aromatic solid epoxy resin having three or more epoxy groups in one molecule is more preferred.

[0083] Preferred solid epoxy resins include bixylenol-type epoxy resins, naphthalene-type epoxy resins, naphthalene-type tetrafunctional epoxy resins, naphthol novolac-type epoxy resins, cresol novolac-type epoxy resins, dicyclopentadiene-type epoxy resins, trisphenol-type epoxy resins, naphthol-type epoxy resins, biphenyl-type epoxy resins, naphthylene ether-type epoxy resins, anthracene-type epoxy resins, bisphenol A-type epoxy resins, bisphenol AF-type epoxy resins, phenol aralkyl-type epoxy resins, tetraphenylethane-type epoxy resins, and phenolphthalimidine-type epoxy resins.

[0084] Specific examples of solid epoxy resins include "HP4032H" (naphthalene type epoxy resin) manufactured by DIC Corporation; "HP-4700" and "HP-4710" (naphthalene type tetrafunctional epoxy resins) manufactured by DIC Corporation; "N-690" (cresol novolac type epoxy resin) manufactured by DIC Corporation; "N-695" (cresol novolac type epoxy resin) manufactured by DIC Corporation; "HP-7200", "HP-7200HH", "HP-7200H", and "HP-7200L" (dicyclopentadiene type epoxy resins) manufactured by DIC Corporation; and "EXA-731" manufactured by DIC Corporation. 1", "EXA-7311-G3", "EXA-7311-G4", "EXA-7311-G4S", "HP6000" (naphthylene ether type epoxy resin); "EPPN-502H" (trisphenol type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; "NC7000L" (naphthol novolac type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; "NC3000H", "NC3000", "NC3000L", "NC3000FH", "NC3100" (biphenyl type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; "ESN475V", "ESN475V" manufactured by Nippon Steel Chemical & Material Co., Ltd. ESN4100V (naphthalene-type epoxy resin); "ESN485" (naphthol-type epoxy resin) manufactured by Nippon Steel Chemical & Material Co., Ltd.; "ESN375" (dihydroxynaphthalene-type epoxy resin) manufactured by Nippon Steel Chemical & Material Co., Ltd.; "YX4000H", "YX4000", "YX4000HK", and "YL7890" (bixylenol-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "YL6121" (biphenyl-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "YX8800" (anthracene-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; Mitsubishi Chemical "YX7700" (phenol aralkyl type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "PG-100" and "CG-500" manufactured by Osaka Gas Chemicals Co., Ltd.; "YL7760" (bisphenol AF type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "YL7800" (fluorene type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "jER1010" (bisphenol A type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "jER1031S" (tetraphenylethane type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "WHR991S" (phenolphthalimidine type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.Examples include "Ogusol PG-100" and "Ogusol CG-500" (epoxy resins containing cardo structure) manufactured by Osaka Gas Chemicals Co., Ltd.;

[0085] In one embodiment, component (B) preferably contains an epoxy resin having an aromatic skeleton, more preferably an epoxy resin having a polycyclic aromatic skeleton containing a fused ring, and even more preferably an epoxy resin having an aromatic skeleton containing at least one selected from the group consisting of a naphthalene skeleton and a cardo skeleton. Examples of aromatic skeletons containing a naphthalene skeleton include a naphthol aralkyl skeleton, a naphthol novolac skeleton, a naphthalene skeleton, a naphthol skeleton, and a naphthylene ether skeleton, with a naphthol aralkyl skeleton and a naphthalene skeleton being preferred. The aromatic skeletons containing a cardo skeleton, including preferred examples thereof, are as described for component (A).

[0086] The epoxy equivalent of component (B) is preferably 50 g / eq. to 5,000 g / eq., more preferably 60 g / eq. to 2,000 g / eq., even more preferably 70 g / eq. to 1,000 g / eq., and even more preferably 80 g / eq. to 500 g / eq. The epoxy equivalent is the mass of resin per equivalent of epoxy groups. This epoxy equivalent can be measured according to JIS K7236.

[0087] The weight average molecular weight (Mw) of component (B) is preferably at least 100, more preferably at least 250, and even more preferably at least 400. The upper limit of Mw of component (B) is preferably not more than 5,000, more preferably not more than 3,000, and even more preferably not more than 1,500. The weight average molecular weight (Mw) is the weight average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC).

[0088] In the photosensitive resin composition set of the present invention, the content of component (B) in the resin composition is preferably 10% by mass or more, more preferably 15% by mass or more, even more preferably 20% by mass or more, 22% by mass or more, 24% by mass or more, or 25% by mass or more, from the viewpoint of being able to further enjoy the effects of the present invention and from the viewpoint of further improving mechanical strength and insulation reliability, and the upper limit is preferably 60% by mass or less, more preferably 50% by mass or less, even more preferably 45% by mass or less, 40% by mass or less, 38% by mass or less, 36% by mass or less, or 35% by mass or less.

[0089] From the viewpoint of being able to enjoy the effects of the present invention more effectively, when the contents of the (A) component and the (B) component in the core resin composition are defined as (A)core and (B)core, respectively, when the non-volatile components of the core resin composition are taken as 100 mass%, it is preferable that the (A)core and (B)core satisfy the relationship 0.1≦(A)core / (B)core≦5. When the component (A) contains the component (a1), the lower limit of the ratio of (A)core / (B)core is more preferably 0.3 or more, even more preferably 0.5 or more, still more preferably 0.6 or more, 0.65 or more, 0.7 or more, 0.75 or more, or 0.8 or more, and the upper limit of the ratio is more preferably 3 or less, even more preferably 2 or less, still more preferably 1.5 or less, 1.4 or less, or 1.2 or less. When the component (A) contains the component (a2), the lower limit of the ratio of (A)core / (B)core is more preferably 0.3 or more, even more preferably 0.5 or more, still more preferably 0.7 or more, 0.9 or more, 0.95 or more, 1.0 or more, 1.05 or more, or 1.1 or more, and the upper limit of the ratio is more preferably 3 or less, even more preferably 2 or less, still more preferably 1.5 or less, 1.4 or less, or 1.3 or less.

[0090] From the viewpoint of being able to enjoy the effects of the present invention more effectively, when the contents of the (A) component and the (B) component in the clad resin composition are defined as (A)clad and (B)clad, respectively, when the non-volatile components of the clad resin composition are taken as 100 mass %, it is preferable that (A)clad and (B)clad satisfy the relationship 0.1≦(A)clad / (B)clad≦5. When the (A) component contains the (a1) component, the lower limit of the (A) clad / (B) clad ratio is more preferably 0.3 or more, even more preferably 0.5 or more, still more preferably 0.6 or more, 0.65 or more, 0.7 or more, 0.75 or more, or 0.8 or more, and the upper limit of the ratio is more preferably 3 or less, even more preferably 2 or less, still more preferably 1.5 or less, 1.4 or less, or 1.2 or less. When the (A) component contains the (a2) component, the lower limit of the (A) clad / (B) clad ratio is more preferably 0.3 or more, even more preferably 0.5 or more, still more preferably 0.7 or more, 0.9 or more, 0.95 or more, 1.0 or more, 1.05 or more, or 1.1 or more, and the upper limit of the ratio is more preferably 3 or less, even more preferably 2 or less, still more preferably 1.5 or less, 1.4 or less, or 1.3 or less.

[0091] <(C) Photocurable resin> In the photosensitive resin composition set of the present invention, the resin composition contains a photocurable resin as component (C). The component (C) may be used alone or in combination of two or more.

[0092] Component (C) does not include components (A) and (B) described above. For example, in relation to component (a1), component (C) does not have to contain a carboxyl group, and in relation to components (a2) and (B), component (C) does not have to contain an epoxy group.

[0093] As the component (C), for example, a (meth)acrylate compound having one or more (preferably two or more) (meth)acryloyl groups in one molecule can be used.

[0094] Examples of the (meth)acrylate compound include hydroxyalkyl acrylates such as 2-hydroxyethyl acrylate and 2-hydroxybutyl acrylate; mono- or diacrylates of glycols such as ethylene glycol, methoxytetraethylene glycol, polyethylene glycol, and propylene glycol; acrylamides such as N,N-dimethylacrylamide and N-methylolacrylamide; aminoalkyl acrylates such as N,N-dimethylaminoethyl acrylate; polyhydric acrylates of polyhydric alcohols such as trimethylolpropane, pentaerythritol, and dipentaerythritol, or their adducts with ethylene oxide, propylene oxide, or ε-caprolactone; acrylates of phenols such as phenoxy acrylate and phenoxyethyl acrylate, or their ethylene oxide or propylene oxide adducts; epoxy acrylates derived from glycidyl ethers such as trimethylolpropane triglycidyl ether; modified epoxy acrylates; melamine acrylates; and / or methacrylates corresponding to the above acrylates.Among these, polyhydric acrylates or polyhydric methacrylates are preferred, and for example, trihydric acrylates or methacrylates include trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, trimethylolpropane EO-adduct tri(meth)acrylate, glycerin PO-adduct tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, tetrafurfuryl alcohol oligo(meth)acrylate, ethyl carbitol oligo(meth)acrylate, 1,4-butanediol oligo(meth)acrylate, 1,6-hexanediol oligo(meth)acrylate, trimethylolpropane oligo(meth)acrylate, pentaerythritol oligo(meth)acrylate, tetramethylolmethane tetra(meth)acrylate, and dipentaerythritol. Examples of the photosensitive (meth)acrylate compounds include hexa(meth)acrylate and (meth)acrylic acid esters of N,N,N',N'-tetrakis(β-hydroxyethyl)ethyldiamine. Examples of the trivalent or higher acrylates or methacrylates include phosphate triester (meth)acrylates such as tri(2-(meth)acryloyloxyethyl)phosphate, tri(2-(meth)acryloyloxypropyl)phosphate, tri(3-(meth)acryloyloxypropyl)phosphate, tri(3-(meth)acryloyl-2-hydroxyloxypropyl)phosphate, di(3-(meth)acryloyl-2-hydroxyloxypropyl)(2-(meth)acryloyloxyethyl)phosphate, and (3-(meth)acryloyl-2-hydroxyloxypropyl)di(2-(meth)acryloyloxyethyl)phosphate. These photosensitive (meth)acrylate compounds may be used alone or in combination of two or more. "EO" refers to ethylene oxide.

[0095] Component (C) can be a commercially available product, such as "DPHA" and "TMPTA" manufactured by Nippon Kayaku Co., Ltd., or "EBECRYL160S," "EBECRYL895," "EBECRYL896," "EBECRYL3708," or "PETA" manufactured by Daicel-Allnex Corporation.

[0096] The weight average molecular weight (Mw) of component (C) is preferably 2,000 or less, more preferably 1,500 or less, and even more preferably 1,000 or less, 800 or less, or 600 or less. There is no particular limitation on the lower limit of Mw of component (C), but it can be, for example, 100 or more, 150 or more, etc. The weight average molecular weight (Mw) is the weight average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC).

[0097] The viscosity of component (C) is typically less than 10 Pa s, and preferably 8 Pa s or less. There is no particular lower limit to the viscosity of component (C), and it can be, for example, 0.001 Pa s or more, 0.005 Pa s or more, or 0.01 Pa s or more. The viscosity of component (C) can be measured using an E-type viscometer at 25±2°C.

[0098] In the photosensitive resin composition set of the present invention, the content of component (C) in the resin composition is, from the viewpoint of being able to further enjoy the effects of the present invention, preferably 15% by mass or more, more preferably 20% by mass or more, even more preferably 25% by mass or more, 26% by mass or more, 28% by mass or more, or 30% by mass or more, and the upper limit is preferably 60% by mass or less, more preferably 50% by mass or less, even more preferably 45% by mass or less, 44% by mass or less, 42% by mass or less, or 40% by mass or less.

[0099] From the viewpoint of enjoying the effects of the present invention, when the content of component (C) in the core resin composition when the non-volatile components of the core resin composition are taken as 100% by mass is defined as (C)core, and when the content of component (C) in the clad resin composition when the non-volatile components of the clad resin composition are taken as 100% by mass is defined as (C)clad, it is preferable that (C)core and (C)clad satisfy the relationship 0.3≦(C)clad / (C)core≦3. The lower limit of the ratio of (C)clad / (C)core is more preferably 0.5 or more, even more preferably 0.7 or more, even more preferably 0.9 or more, or 0.95 or more, and the upper limit of the ratio is more preferably 2 or less, even more preferably 1.5 or less, even more preferably 1.4 or less, 1.35 or less, or 1.3 or less. In particular, from the viewpoint of enjoying the effects of the present invention, a ratio of (C)clad / (C)core in the range of 0.9 to 1.5 is preferable. Therefore, in a preferred embodiment, (C)core and (C)clad satisfy the relationship 0.9≦(C)clad / (C)core≦1.5.

[0100] From the viewpoint of obtaining the effects of the present invention more effectively, when the contents of the (A) component and the (C) component in the core resin composition are defined as (A)core and (C)core, respectively, when the non-volatile components of the core resin composition are taken as 100 mass%, it is preferable that the (A)core and (C)core satisfy the relationship 0.1≦(A)core / (C)core≦5. When the component (A) contains the component (a1), the lower limit of the ratio of (A)core / (C)core is more preferably 0.3 or more, even more preferably 0.5 or more, still more preferably 0.6 or more, 0.7 or more, 0.8 or more, 0.9 or more, or 1.0 or more, and the upper limit of the ratio is more preferably 3 or less, even more preferably 2 or less, still more preferably 1.5 or less, 1.4 or less, or 1.2 or less. When the component (A) contains the component (a2), the lower limit of the ratio of (A)core / (C)core is more preferably 0.3 or more, even more preferably 0.5 or more, still more preferably 0.6 or more, 0.7 or more, 0.8 or more, or 0.9 or more, and the upper limit of the ratio is more preferably 3 or less, even more preferably 2 or less, still more preferably 1.5 or less, 1.4 or less, or 1.2 or less.

[0101] From the viewpoint of being able to enjoy the effects of the present invention more effectively, when the contents of the (A) component and the (C) component in the clad resin composition are defined as (A)clad and (C)clad, respectively, when the non-volatile components of the clad resin composition are taken as 100 mass %, it is preferable that the (A)clad and (C)clad satisfy the relationship 0.1≦(A)clad / (C)clad≦5. When the (A) component contains the (a1) component, the lower limit of the (A) clad / (C) clad ratio is more preferably 0.3 or more, even more preferably 0.5 or more, still more preferably 0.6 or more, 0.7 or more, 0.8 or more, or 0.9 or more, and the upper limit of the ratio is more preferably 3 or less, even more preferably 2 or less, still more preferably 1.5 or less, 1.4 or less, or 1.2 or less. When the (A) component contains the (a2) component, the lower limit of the (A) clad / (C) clad ratio is more preferably 0.3 or more, even more preferably 0.5 or more, still more preferably 0.6 or more, 0.7 or more, 0.8 or more, or 0.9 or more, and the upper limit of the ratio is more preferably 3 or less, even more preferably 2 or less, still more preferably 1.5 or less, 1.4 or less, or 1.2 or less.

[0102] <(D) Photopolymerization initiator> In the photosensitive resin composition set of the present invention, the resin composition contains a photopolymerization initiator as component (D). By including component (D), the resin composition can be efficiently photocured. Component (D) may be used alone or in combination of two or more. Note that component (D) does not include components (A), (B), and (C) described above.

[0103] Any compound can be used as component (D), for example, acylphosphine oxide-based photopolymerization initiators such as bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide; oxime ester-based photopolymerization initiators such as 1,2-octanedione, 1-4-(phenylthio)-2-(O-benzoyloxime), ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-, 1-(O-acetyloxime); 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-1-butanone, 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-[4-(4-morpholinyl)phenyl]-1-butanone, 2-methyl-1-[4-(methylthio) α-aminoalkylphenone photopolymerization initiators such as benzophenone, methylbenzophenone, o-benzoylbenzoic acid, benzoyl ethyl ether, 2,2-diethoxyacetophenone, 2,4-diethylthioxanthone, diphenyl-(2,4,6-trimethylbenzoyl)phosphine oxide, ethyl-(2,4,6-trimethylbenzoyl)phenylphosphinate, 4,4'-bis(diethylamino)benzophenone, 1-hydroxycyclohexylphenyl ketone, 2,2-dimethoxy-1,2-diphenylethan-1-one, and 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propan-1-one. Sulfonium salt photopolymerization initiators can also be used. These may be used alone or in combination. Among these, from the viewpoint of more efficiently photocuring the resin composition, either an acylphosphine oxide-based photopolymerization initiator or an oxime ester-based photopolymerization initiator is preferred, and an acylphosphine oxide-based photopolymerization initiator is more preferred.

[0104] Specific examples of the component (D) include "Omnirad907," "Omnirad369," "Omnirad379," "Omnirad819," and "OmniradTPO" manufactured by IGM Resins; "IrgacureOXE-01," "IrgacureOXE-02," "IrgacureTPO," and "Irgacure819" manufactured by BASF; and "N-1919" manufactured by ADEKA Corporation.

[0105] In the photosensitive resin composition set of the present invention, when the component (a1) is included as the component (A), the content of the component (D) in the resin composition is, from the viewpoint of better enjoying the effects of the present invention, preferably 0.1% by mass or more, more preferably 0.5% by mass or more, even more preferably 1% by mass or more, still more preferably 1.5% by mass or more, 2% by mass or more, 2.5% by mass or more, or 3% by mass or more, and the upper limit is preferably 20% by mass or less, more preferably 15% by mass or less, even more preferably 10% by mass or less, 8% by mass or less, 6% by mass or less, or 5% by mass or less. Furthermore, when the component (a2) is included as the component (A), the content of the component (D) in the resin composition is, from the viewpoint of being able to enjoy the effects of the present invention more effectively, preferably 0.01% by mass or more, more preferably 0.05% by mass or more, even more preferably 0.1% by mass or more, still more preferably 0.15% by mass or more, 0.2% by mass or more, 0.25% by mass or more, or 0.3% by mass or more, and the upper limit is preferably 10% by mass or less, more preferably 5% by mass or less, even more preferably 4% by mass or less, 3% by mass or less, 2% by mass or less, or 1% by mass or less.

[0106] In the photosensitive resin composition set of the present invention, when the resin composition contains the component (a1) as the component (A), the content of the component (D) in the resin composition is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, even more preferably 3 parts by mass or more, 4 parts by mass or more, or 5 parts by mass or more, when the total amount of the non-volatile components of the components (A) and (C) in the resin composition is taken as 100 parts by mass, and the upper limit is preferably 20 parts by mass or less, more preferably 15 parts by mass or less, even more preferably 10 parts by mass or less, 8 parts by mass or less, or 7 parts by mass or less. Furthermore, when the (A) component contains the (a2) component, the content of the (D) component in the resin composition, when the total amount of the non-volatile components of the (A) component and the (C) component of the resin composition is taken as 100 parts by mass, is preferably 0.05 parts by mass or more, more preferably 0.1 parts by mass or more, even more preferably 0.3 parts by mass or more, 0.4 parts by mass or more, or 0.5 parts by mass or more, and the upper limit is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, even more preferably 4 parts by mass or less, 3 parts by mass or less, 2 parts by mass or less, or 1 part by mass or less.

[0107] <(E) Alkoxysilane Compound> In the photosensitive resin composition set of the present invention, at least the cladding resin composition contains, as component (E), an alkoxysilane compound having one or more functional groups selected from the group consisting of an epoxy group, a phenylamino group, a vinyl group, and a (meth)acryloyl group. Component (E) may be used singly or in combination of two or more types.

[0108] In addition, the core resin composition may also contain component (E) as long as the relationship 0.6≦(E)clad−(E)core≦10 is satisfied.

[0109] The component (E) is more preferably at least one selected from the group consisting of alkoxy group-containing silane coupling agents having the above specific functional groups and oligomers thereof (hereinafter also referred to as "alkoxy oligomers").

[0110] In one embodiment, the component (E) is an alkoxy group-containing silane coupling agent represented by the following formula (E1):

[0111] X-Si(OR 1 ) a (R 2 ) 3-a (E1) (In formula (E1), X represents a monovalent organic group having one or more functional groups selected from the group consisting of an epoxy group, a phenylamino group, a vinyl group, and a (meth)acryloyl group; R 1 represents an alkyl group having 1 to 3 carbon atoms, an alkoxyalkyl group having 2 to 8 carbon atoms, or an aryl group having 6 to 10 carbon atoms, R 2 represents a hydrogen atom, a hydroxy group, a halogen atom, or a hydrocarbon group; a represents an integer of 1 to 3. When a is 2 or 3, a plurality of R 1 may be the same or different. When a is 1, multiple R 2 may be the same or different.)

[0112] In formula (E1), X represents a monovalent organic group having one or more functional groups selected from the group consisting of an epoxy group, a phenylamino group, a vinyl group, and a (meth)acryloyl group. When X represents a monovalent organic group having an epoxy group, X is an epoxy C6-C 10 Cycloalkyl-C1-C6 alkyl group, glycidyl C6-C 10 It is preferably one or more selected from an aryl group and a glycidoxy-C1 to C6 alkyl group. When X represents a monovalent organic group having a phenylamino group, X is preferably an N-phenyl-amino-C1 to C6 alkyl group. When X represents a monovalent organic group having a vinyl group, X is preferably at least one selected from a vinyl group and a vinyl-C1 to C6 alkyl group. When X represents a monovalent organic group having a (meth)acryloyl group, X is preferably a (meth)acryloyloxy-C1 to C6 alkyl group.

[0113] In order to obtain the effects of the present invention more effectively, a is preferably 2 or 3, and more preferably 3.

[0114] R 2The hydrocarbon group represented by the formula (I) may be either an aliphatic hydrocarbon group or an aromatic hydrocarbon group, as described above, but among these, an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 10 carbon atoms, or an arylalkyl group having 7 to 14 carbon atoms is preferred.

[0115] As such an alkoxy group-containing silane coupling agent, commercially available products may be used. Commercially available alkoxy group-containing silane coupling agents containing epoxy groups include "X-12-1231" (3-(2-glycidylphenyl)propyltrimethoxysilane), "KBM-403" (3-glycidoxypropyltrimethoxysilane), "KBM-303" (2-(3,4)-epoxycyclohexyl)ethyltrimethoxysilane), "KBM-402" (3-glycidoxypropylmethyldimethoxysilane), "KBE-403" (3-glycidoxypropyltriethoxysilane), "KBE-402" (3-glycidoxypropylmethyldiethoxysilane), and "KBM-4803" (8-glycidoxyoctyltrimethoxysilane), all manufactured by Shin-Etsu Chemical Co., Ltd. Commercially available alkoxy group-containing silane coupling agents containing phenylamino groups include "KBM-573" (N-phenyl-3-aminopropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd. Commercially available alkoxy group-containing silane coupling agents containing vinyl groups include "KBE-1003" (vinyltriethoxysilane), "KBM-1003" (vinyltrimethoxysilane), and "KBM-1083" (trimethoxy(7-octen-1-yl)silane) manufactured by Shin-Etsu Chemical Co., Ltd. Commercially available alkoxy group-containing silane coupling agents containing (meth)acryloyl groups include "KBM-503" (3-methacryloxypropyltrimethoxysilane), "KBE-503" (3-methacryloxypropyltriethoxysilane), "KBM-502" (3-methacryloxypropylmethyldimethoxysilane), "KBE-502" (3-methacryloxypropylmethyldiethoxysilane), "KBM-5803" (8-methacryloxyoctyltrimethoxysilane), and "KBM-5103" (3-acryloxypropyltrimethoxysilane), all manufactured by Shin-Etsu Chemical Co., Ltd.

[0116] The alkoxy oligomer is not particularly limited as long as it is an oligomer of the above-mentioned alkoxy group-containing silane coupling agent. Specific examples of such alkoxy oligomers include epoxy group-containing alkoxysilyl resins, phenylamino group-containing alkoxysilyl resins, vinyl group-containing alkoxysilyl resins, and (meth)acryloyl group-containing alkoxysilyl resins.

[0117] Commercially available alkoxy oligomers may be used. Commercially available epoxy group-containing alkoxysilyl resins include "X-41-1053," "X-41-1059A," and "X-41-1056" manufactured by Shin-Etsu Chemical Co., Ltd. Commercially available phenylamino group-containing alkoxysilyl resins include "X-40-9281" manufactured by Shin-Etsu Chemical Co., Ltd. Commercially available (meth)acryloyl group-containing alkoxysilyl resins include "X-22-164" and "X-22-164AS" manufactured by Shin-Etsu Chemical Co., Ltd.

[0118] In the photosensitive resin composition set of the present invention, when the content (% by mass) of component (E) in the core resin composition when the non-volatile components of the core resin composition are taken as 100% by mass is defined as (E)core, and the content (% by mass) of component (E) in the clad resin composition when the non-volatile components of the clad resin composition are taken as 100% by mass, it is important that (E)core and (E)clad satisfy the relationship 0.6≦(E)clad−(E)core≦10. When (E)core and (E)clad satisfy the above relationship, the effect of the present invention can be achieved, that is, a single-mode optical waveguide can be produced in which the change in optical transmission loss before and after a reliability test is small. The difference between (E)core and (E)clad, i.e., the value of (E)clad-(E)core, is preferably 0.8 or more, more preferably 1 or more, even more preferably 1.2 or more, 1.4 or more, or 1.5 or more, and the upper limit thereof is preferably 10 or less, more preferably 8 or less, even more preferably 6 or less, 5.5 or less, 5 or less, 4.5 or less, or 4 or less.

[0119] In the photosensitive resin composition set of the present invention, the content of component (E) in the cladding resin composition is 0.6% by mass or more, preferably 0.8% by mass or more, more preferably 1% by mass or more, 1.2% by mass or more, 1.4% by mass or more, or 1.5% by mass or more, and even more preferably 1.6% by mass or more, 1.8% by mass or more, or 2% by mass or more, and the upper limit is preferably 14% by mass or less, more preferably 12% by mass or less, and even more preferably 10% by mass or less, 8% by mass or less, 7% by mass or less, 6% by mass or less, or 5% by mass or less. Therefore, in one embodiment, the content of component (E) in the cladding resin composition, i.e., (E)clad, is 1 to 12% by mass when the non-volatile components of the cladding resin composition are taken as 100% by mass.

[0120] As described above, the core resin composition may contain component (E) as long as the difference between (E)core and (E)clad, i.e., the above relationship (E)clad-(E)core, is satisfied. When the core resin composition contains component (E), the content of component (E) in the core resin composition is not particularly limited, but is preferably 10% by mass or less, more preferably 5% by mass or less, and even more preferably 4% by mass or less, 3% by mass or less, 2% by mass or less, or 1% by mass or less. The lower limit of the content may be 0% by mass, but may also be, for example, more than 0% by mass, 0.001% by mass or more, 0.01% by mass or more, 0.1% by mass or more, or 0.2% by mass or more.

[0121] <(F) Curing accelerator> In the photosensitive resin composition set of the present invention, the resin composition may contain a curing accelerator (F) as an optional component. Component (F) functions as a curing catalyst that accelerates the curing of component (B) and the like. Component (F) may be used alone or in combination of two or more. Note that component (F) does not include components (A) to (E) above.

[0122] Examples of component (F) include imidazole-based curing accelerators, phosphorus-based curing accelerators, urea-based curing accelerators, guanidine-based curing accelerators, metal-based curing accelerators, and amine-based curing accelerators. Of these, imidazole-based curing accelerators are preferred.

[0123] Examples of the imidazole curing accelerator include 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, and 1-benzyl-2-methylimidazole. Phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-phenylimidazolium trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino-6-[2'-methylimidazolyl -(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-undecylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct Examples of imidazole compounds include 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidazole, 1-dodecyl-2-methyl-3-benzylimidazolium chloride, 2-methylimidazoline, and 2-phenylimidazoline, as well as adducts of imidazole compounds with epoxy resins. Commercially available imidazole curing accelerators include "1B2PZ," "2E4MZ," "2MZA-PW," "2MZ-OK," "2MA-OK," "2MA-OK-PW," "2PHZ," "2PHZ-PW," "Cl1Z," "Cl1Z-CN," "Cl1Z-CNS," and "C11Z-A" manufactured by Shikoku Chemicals Corporation; and "P200-H50" manufactured by Mitsubishi Chemical Corporation.

[0124] Examples of the phosphorus-based curing accelerator include aliphatic phosphonium salts such as tetrabutylphosphonium bromide, tetrabutylphosphonium chloride, tetrabutylphosphonium acetate, tetrabutylphosphonium decanoate, tetrabutylphosphonium laurate, bis(tetrabutylphosphonium)pyromellitate, tetrabutylphosphonium hydrogenhexahydrophthalate, tetrabutylphosphonium 2,6-bis[(2-hydroxy-5-methylphenyl)methyl]-4-methylphenolate, and di-tert-butyldimethylphosphonium tetraphenylborate; methyltriphenylphosphonium bromide, ethyltriphenylphosphonium bromide, propyltriphenylphosphonium bromide, butyltriphenylphosphonium bromide, benzyltriphenylphosphonium chloride, tetraphenylphosphonium bromide, p-tolyltriphenylphosphonium tetra-p-tolylborate, and tetraphenylphosphonium tetra-p-tolylborate. aromatic phosphonium salts such as tetraphenylborate, tetraphenylphosphonium tetra-p-tolylborate, triphenylethylphosphonium tetraphenylborate, tris(3-methylphenyl)ethylphosphonium tetraphenylborate, tris(2-methoxyphenyl)ethylphosphonium tetraphenylborate, (4-methylphenyl)triphenylphosphonium thiocyanate, tetraphenylphosphonium thiocyanate, and butyltriphenylphosphonium thiocyanate; aromatic phosphine-borane complexes such as triphenylphosphine-triphenylborane; aromatic phosphine-quinone adducts such as triphenylphosphine-p-benzoquinone adduct; aliphatic phosphines such as tributylphosphine, tri-tert-butylphosphine, trioctylphosphine, di-tert-butyl(2-butenyl)phosphine, di-tert-butyl(3-methyl-2-butenyl)phosphine, and tricyclohexylphosphine;Dibutylphenylphosphine, di-tert-butylphenylphosphine, methyldiphenylphosphine, ethyldiphenylphosphine, butyldiphenylphosphine, diphenylcyclohexylphosphine, triphenylphosphine, tri-o-tolylphosphine, tri-m-tolylphosphine, tri-p-tolylphosphine, tris(4-ethylphenyl)phosphine, tris(4-propylphenyl)phosphine, tris(4-isopropylphenyl)phosphine, tris(4-butylphenyl)phosphine, tris(4-tert-butylphenyl)phosphine, tris(2,4-dimethylphenyl)phosphine, tris(2,5-dimethylphenyl)phosphine, tris(2,6-dimethylphenyl)phosphine aromatic phosphines such as benzene, tris(3,5-dimethylphenyl)phosphine, tris(2,4,6-trimethylphenyl)phosphine, tris(2,6-dimethyl-4-ethoxyphenyl)phosphine, tris(2-methoxyphenyl)phosphine, tris(4-methoxyphenyl)phosphine, tris(4-ethoxyphenyl)phosphine, tris(4-tert-butoxyphenyl)phosphine, diphenyl-2-pyridylphosphine, 1,2-bis(diphenylphosphino)ethane, 1,3-bis(diphenylphosphino)propane, 1,4-bis(diphenylphosphino)butane, 1,2-bis(diphenylphosphino)acetylene, and 2,2'-bis(diphenylphosphino)diphenyl ether;

[0125] Examples of the urea-based curing accelerator include 1,1-dimethylurea; aliphatic dimethylureas such as 1,1,3-trimethylurea, 3-ethyl-1,1-dimethylurea, 3-cyclohexyl-1,1-dimethylurea, and 3-cyclooctyl-1,1-dimethylurea; 3-phenyl-1,1-dimethylurea, 3-(4-chlorophenyl)-1,1-dimethylurea, 3-(3,4-dichlorophenyl)-1,1-dimethylurea, 3-(3-chloro-4-methylphenyl)-1,1-dimethylurea, 3-(2-methylphenyl)-1,1-dimethylurea, 3-(4-methylphenyl)-1,1-dimethylurea, and 3-(3,4-dimethylphenyl)-1,1-dimethylurea. aromatic dimethylureas such as toluene bis(dimethylurea), 3-(4-isopropylphenyl)-1,1-dimethylurea, 3-(4-methoxyphenyl)-1,1-dimethylurea, 3-(4-nitrophenyl)-1,1-dimethylurea, 3-[4-(4-methoxyphenoxy)phenyl]-1,1-dimethylurea, 3-[4-(4-chlorophenoxy)phenyl]-1,1-dimethylurea, 3-[3-(trifluoromethyl)phenyl]-1,1-dimethylurea, N,N-(1,4-phenylene)bis(N',N'-dimethylurea), and N,N-(4-methyl-1,3-phenylene)bis(N',N'-dimethylurea) [toluene bisdimethylurea].

[0126] Examples of guanidine curing accelerators include dicyandiamide, 1-methylguanidine, 1-ethylguanidine, 1-cyclohexylguanidine, 1-phenylguanidine, 1-(o-tolyl)guanidine, dimethylguanidine, diphenylguanidine, trimethylguanidine, tetramethylguanidine, pentamethylguanidine, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene, 1-methylbiguanide, 1-ethylbiguanide, 1-n-butylbiguanide, 1-n-octadecylbiguanide, 1,1-dimethylbiguanide, 1,1-diethylbiguanide, 1-cyclohexylbiguanide, 1-allylbiguanide, 1-phenylbiguanide, and 1-(o-tolyl)biguanide.

[0127] Examples of metal-based curing accelerators include organometallic complexes or organometallic salts of metals such as cobalt, copper, zinc, iron, nickel, manganese, and tin. Specific examples of organometallic complexes include organic cobalt complexes such as cobalt(II) acetylacetonate and cobalt(III) acetylacetonate, organic copper complexes such as copper(II) acetylacetonate, organic zinc complexes such as zinc(II) acetylacetonate, organic iron complexes such as iron(III) acetylacetonate, organic nickel complexes such as nickel(II) acetylacetonate, and organic manganese complexes such as manganese(II) acetylacetonate. Examples of organometallic salts include zinc octoate, tin octoate, zinc naphthenate, cobalt naphthenate, tin stearate, and zinc stearate.

[0128] Examples of the amine curing accelerator include trialkylamines such as triethylamine and tributylamine, 4-dimethylaminopyridine, benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, 1,8-diazabicyclo(5,4,0)-undecene, etc. Commercially available amine curing accelerators may be used, such as "MY-25" manufactured by Ajinomoto Fine-Techno Co., Inc.

[0129] In the photosensitive resin composition set of the present invention, the content of the component (F) in the resin composition is not particularly limited, and may be, for example, 0% by mass or more, 0.001% by mass or more, 0.01% by mass or more, 0.1% by mass or more, 0.3% by mass or more, etc. The upper limit of the content of the component (F) in the resin composition is preferably 5% by mass or less, more preferably 3% by mass or less, and even more preferably 1% by mass or less, 0.8% by mass or less, or 0.6% by mass or less.

[0130] <(G) Other additives> In the photosensitive resin composition set of the present invention, the resin composition may further contain (G) other additives to the extent that the object of the present invention is not impaired. Examples of (G) other additives include epoxy resin curing agents such as active ester curing agents, phenolic curing agents, carbodiimide curing agents, acid anhydride curing agents, amine curing agents, benzoxazine curing agents, and cyanate ester curing agents; photosensitizers such as pyrarizones, anthracenes, coumarins, xanthones, and thioxanthones; inorganic fillers such as silica, alumina, and aluminosilicates; thermoplastic resins; organic fillers, fine particles such as melamine and organic bentonite; phthalocyanine blue, phthalocyanine green, iodine green, diazo yellow, crystal violet, titanium oxide, and carbon black. naphthalene black and other colorants; polymerization inhibitors such as hydroquinone, phenothiazine, methylhydroquinone, hydroquinone monomethyl ether, catechol, and pyrogallol; thickeners such as bentone and montmorillonite; silicone-based, fluorine-based, and vinyl resin-based defoamers; flame retardants such as brominated epoxy compounds, acid-modified brominated epoxy compounds, antimony compounds, phosphorus-based compounds, aromatic condensed phosphate esters, and halogen-containing condensed phosphate esters; ultraviolet absorbers; and various additives such as plasticizers, antistatic agents, antioxidants, antibacterial agents, leveling agents, adhesion imparting agents, thixotropy imparting agents, release agents, surface treatment agents, dispersants, surface modifiers, and stabilizers.

[0131] <(H) Organic Solvent> In the photosensitive resin composition set of the present invention, the resin composition may contain an organic solvent (H) as a volatile component in combination with the nonvolatile components (A) to (G) described above. By including the component (H), the viscosity of the resin composition can be adjusted, and an ink-type resin composition (resin ink) can be prepared. The component (H) may be used alone or in combination of two or more.

[0132] Examples of (H) organic solvents include ketone solvents such as ethyl methyl ketone (MEK) and cyclohexanone; aromatic hydrocarbon solvents such as toluene, xylene, and tetramethylbenzene; glycol ether solvents such as methyl cellosolve, butyl cellosolve, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol diethyl ether, and triethylene glycol monoethyl ether; ester solvents such as ethyl acetate, butyl acetate, butyl cellosolve acetate, carbitol acetate, and ethyl diglycol acetate; ether ester solvents such as propylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl diglycol acetate, γ-butyrolactone, and methyl methoxypropionate; aliphatic hydrocarbon solvents such as octane and decane; and petroleum-based solvents such as petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, and solvent naphtha.

[0133] The content of the component (H) in the resin composition is preferably adjusted appropriately from the viewpoint of the coatability of the resin composition (resin ink).

[0134] [Method of producing resin composition] In the photosensitive resin composition set of the present invention, the resin composition can be produced by mixing the components to be contained in the resin composition. Thus, in the photosensitive resin composition set of the present invention, the core resin composition can be produced by mixing components (A) to (D) and, if necessary, components (E) to (H), and the cladding resin composition can be produced by mixing components (A) to (E) and, if necessary, components (F) to (H). During mixing, kneading may be performed using a kneading device such as a three-roll mill, ball mill, bead mill, or sand mill, or stirring may be performed using a stirring device such as a super mixer or planetary mixer. There is no limitation on the order in which the components are mixed. Furthermore, cooling or heating may be performed during the process of mixing the components.

[0135] [Photosensitive resin composition set properties and uses] In the photosensitive resin composition set of the present invention, the core resin composition can provide a cured product exhibiting a refractive index suitable for forming an optical waveguide. core is not particularly limited as long as an optical waveguide having a desired numerical aperture NA can be formed. For example, the refractive index n of the cured product of the core resin composition at a measurement wavelength of 1310 nm is core is preferably 1.3 or more, more preferably 1.4 or more, even more preferably 1.5 or more, and is preferably 2 or less, more preferably 1.9 or less, even more preferably 1.8 or less. core can be measured by the method (for a resin sheet) described later in <Test Example 1: Measurement of the refractive index of a cured product of a resin composition using a resin sheet>, or the method (for a resin ink) described later in <Test Example 8: Measurement of the refractive index of a cured product of a resin composition using a resin ink>.

[0136] In the photosensitive resin composition set of the present invention, the cladding resin composition can provide a cured product exhibiting a refractive index suitable for forming an optical waveguide. clad is not particularly limited as long as an optical waveguide having a desired numerical aperture NA can be formed. For example, the refractive index n of the cured product of the cladding resin composition at a measurement wavelength of 1310 nm is clad is preferably 1.3 or more, more preferably 1.4 or more, even more preferably 1.5 or more, and is preferably 2 or less, more preferably 1.9 or less, even more preferably 1.8 or less. clad can be measured by the method (for a resin sheet) described later in <Test Example 1: Measurement of the refractive index of a cured product of a resin composition using a resin sheet>, or the method (for a resin ink) described later in <Test Example 8: Measurement of the refractive index of a cured product of a resin composition using a resin ink>.

[0137] The photosensitive resin composition set of the present invention has a refractive index n such that the numerical aperture NA, represented by the following formula (1), falls within a specific range: core and refractive index n clad may have:

[0138]

number

[0139] In formula (2), n core represents the refractive index of the cured product of the core resin composition, and n clad represents the refractive index of the cured product of the cladding resin composition. core and refractive index n clad The measurement wavelength is the wavelength of light transmitted through the optical waveguide, and is, for example, 1310 nm. The numerical aperture NA is, specifically, for example, 0.03 or more, preferably 0.04 or more, more preferably 0.05 or more, or 0.06 or more. The upper limit of the numerical aperture NA is, for example, less than 0.3, preferably 0.2 or less, more preferably 0.18 or less, and even more preferably 0.16 or less, or 0.15 or less.

[0140] The photosensitive resin composition set of the present invention allows the production of an optical waveguide having a small optical transmission loss. For example, when the optical transmission loss of the optical waveguide is measured according to the method described later in <Test Example 6: Measurement of Optical Transmission Loss> (for a resin sheet) or the method described later in <Test Example 12: Measurement of Optical Transmission Loss> (for a resin ink), the optical transmission loss (before reliability testing; L1) is preferably 0.50 dB / cm or less, more preferably 0.45 dB / cm or less, and even more preferably 0.44 dB / cm or less, 0.42 dB / cm or less, 0.4 dB / cm or less, or 0.38 dB / cm or less.

[0141] The photosensitive resin composition set of the present invention allows the production of optical waveguides with small changes in optical transmission loss before and after reliability testing. For example, when the optical transmission loss of an optical waveguide is measured according to the method described below in <Test Example 6: Measurement of Optical Transmission Loss> (for a resin sheet) or the method described below in <Test Example 12: Measurement of Optical Transmission Loss> (for a resin ink), the rate of change in the optical transmission loss (L2) after a moist heat and humidity test (HAST test) (130°C, 85% RH, 100 hours) or a heat resistance test (reflow test) from the optical transmission loss (L1) before the test is preferably less than 40%, more preferably less than 30%, and even more preferably less than 20%, 18%, 16%, 15%, 14%, 12%, or 10%. Combined with the small optical transmission loss (L1) before the test, optical waveguides produced using the photosensitive resin composition set of the present invention are characterized by small optical transmission loss (L2) after the test. The optical transmission loss value (L2) of an optical waveguide produced using the photosensitive resin composition set of the present invention after a HAST test or a reflow test may be preferably 0.60 dB / cm or less, more preferably 0.55 dB / cm or less, and even more preferably 0.54 dB / cm or less, 0.52 dB / cm or less, 0.50 dB / cm or less, 0.48 dB / cm or less, 0.46 dB / cm or less, or 0.45 dB / cm or less.

[0142] The photosensitive resin composition set of the present invention can provide excellent resolution (narrow-wire waveguide formability) when producing an optical waveguide. For example, when an attempt was made to form a 5 μm-thick line layer with an L / S (line / space) of 5 μm / 5 μm, a 7 μm-thick line layer with an L / S (line / space) of 7 μm / 7 μm, and a 50 μm-thick line layer with an L / S (line / space) of 50 μm / 50 μm according to the method described below in <Test Example 3: Evaluation of Resolution (Narrow-Wire Waveguide Formability)>, it was possible to form preferably a line layer with a 7 μm-thick line width or a 50 μm-thick line layer with a 50 μm-thick line width, and more preferably a line layer with a 5 μm-thick line width, a 7 μm-thick line layer with a 7 μm-thick line width, and a 50 μm-thick line layer with a 50 μm-thick line width.

[0143] The photosensitive resin composition set of the present invention can be used to produce an optical waveguide having a small difference in shrinkage rate between the core layer and the clad layer. For example, the shrinkage rate c of the core layer calculated according to the method described later in <Test Example 5: Evaluation of the difference in shrinkage rate between the core layer and the clad layer> can be calculated as follows: core and the shrinkage rate of the cladding layer, c clad Difference from |c core -c clad | may be preferably less than 0.07, more preferably 0.06 or less, and even more preferably 0.05 or less, 0.04 or less, 0.03 or less, 0.02 or less, or 0.01 or less.

[0144] The photosensitive resin composition set of the present invention allows the production of an optical waveguide that exhibits good adhesion to the substrate. For example, when a resin composition layer is formed on a substrate electrical circuit board according to the method described later in <Test Example 4: Evaluation of Adhesion to Substrate> and subjected to a HAST test (130°C, 85% RH, 100 hours), no peeling occurs at the interface with the substrate electrical circuit board, and good adhesion is exhibited.

[0145] According to the photosensitive resin composition set of the present invention, when used as a resin ink, it is possible to obtain a cured product that is free of bubbles and has a good appearance. For example, a resin ink is applied according to the method described later in <Test Example 11: Appearance after curing> and photocured (2 J / cm 2 When subjected to UV irradiation (at 190°C for 90 minutes) and thermal curing (at 190°C for 90 minutes), a cured product with a good appearance and no bubbles can be obtained.

[0146] In the photosensitive resin composition set of the present invention, the core resin composition can be used as a resin composition for forming a core layer of an optical waveguide. For example, the core resin composition can be used to form an optical waveguide capable of transmitting light with a wavelength of 1300 nm to 1320 nm. In particular, the core resin composition is preferably used to form a single-mode optical waveguide, for example, a single-mode optical waveguide for light with a wavelength of 1310 nm.

[0147] In the photosensitive resin composition set of the present invention, the cladding resin composition can be used as a resin composition for forming a cladding layer of an optical waveguide. For example, the cladding resin composition can be used to form an optical waveguide capable of transmitting light having a wavelength of 1300 nm to 1320 nm. In particular, the cladding resin composition is preferably used to form a single-mode optical waveguide, for example, a single-mode optical waveguide for light having a wavelength of 1310 nm.

[0148] As described above, the photosensitive resin composition set of the present invention can be suitably used for producing an optical waveguide, and more suitably used for producing an optical waveguide capable of transmitting light having a wavelength of 1300 nm to 1320 nm. Furthermore, the photosensitive resin composition set of the present invention can be suitably used for producing a single-mode optical waveguide in particular.

[0149] [Photosensitive resin sheet set] Each resin composition in the photosensitive resin composition set of the present invention can be used to produce a resin sheet. Specifically, a core resin sheet can be produced using the core resin composition, and a clad resin sheet can be produced using the clad resin composition. The present invention also provides a photosensitive resin sheet set including such a core resin sheet and a clad resin sheet.

[0150] In the photosensitive resin sheet set of the present invention, the core resin sheet has a resin composition layer containing the core resin composition in the photosensitive resin composition set of the present invention, and the clad resin sheet has a resin composition layer containing the clad resin composition in the photosensitive resin composition set of the present invention.

[0151] The photosensitive resin sheet set of the present invention can be suitably used for producing an optical waveguide. The photosensitive resin sheet set of the present invention can provide the same advantages as the photosensitive resin composition set described above, and furthermore, enables the production of an optical waveguide by a lamination method, making it easier to produce an optical waveguide.

[0152] In one embodiment, the photosensitive resin sheet set of the present invention includes: a core resin sheet including a support and a resin composition layer including a core resin composition provided on the support; a clad resin sheet including a support and a resin composition layer including a clad resin composition provided on the support; Includes:

[0153] Examples of the support include polyethylene terephthalate film, polyethylene naphthalate film, polypropylene film, polyethylene film, polyvinyl alcohol film, and triacetyl acetate film, with polyethylene terephthalate film being particularly preferred.

[0154] Commercially available supports include, but are not limited to, polyethylene terephthalate films such as those manufactured by Oji Paper Co., Ltd. under the product names "Alphan MA-410" and "E-200C," polypropylene films manufactured by Shin-Etsu Film Co., Ltd., and the PS series manufactured by Teijin Limited under the product name "PS-25." These supports are preferably coated with a release agent such as a silicone coating agent on the surface to facilitate removal of the resin composition layer. The thickness of the support is preferably in the range of 5 μm to 50 μm, and more preferably in the range of 10 μm to 25 μm. A thickness of 5 μm or more can prevent the support from breaking when peeling off the support before development, while a thickness of 50 μm or less can improve resolution when exposing from the support. Supports with low fisheyes are also preferred. Here, fisheyes refer to foreign matter, undissolved matter, oxidized degradation products, etc., introduced into the film during film production by thermally melting the material and then kneading, extrusion, biaxial stretching, casting, or other methods.

[0155] In addition, in order to reduce scattering of light during exposure to actinic rays such as ultraviolet rays, the support is preferably one with excellent transparency. Specifically, the support is preferably one with a turbidity (haze standardized by JIS-K6714), which is an index of transparency, of 0.1 to 5.

[0156] In the photosensitive resin sheet set of the present invention, the resin composition layer may be protected with a protective film, regardless of whether it is a core resin sheet or a clad resin sheet. Protecting the resin composition layer side of the resin sheet with a protective film (cover film) can prevent the adhesion of dust and other particles to the surface of the resin composition layer and prevent scratches. The protective film can be made of the same material as the support. The thickness of the protective film is not particularly limited, but is preferably in the range of 1 μm to 40 μm, more preferably in the range of 5 μm to 30 μm, and even more preferably in the range of 10 μm to 30 μm. A thickness of 1 μm or more can improve the handleability of the protective film, while a thickness of 40 μm or less tends to improve cost. It is preferable that the adhesive strength between the resin composition layer and the protective film is smaller than the adhesive strength between the resin composition layer and the support.

[0157] A resin sheet can be produced, for example, by preparing a resin varnish by dissolving the resin composition of the present invention in an organic solvent, applying the resin varnish to a support, and drying the organic solvent by heating or hot air blowing, etc., to form a resin composition layer. To produce a core resin sheet, a core resin composition can be used, and to produce a clad resin sheet, a clad resin composition can be used. Specifically, after first removing bubbles from the resin composition by vacuum degassing or the like, the resin composition is applied to a support, the solvent is removed using a hot air oven or far-infrared oven, and the resulting resin composition is dried. If necessary, a protective film can be laminated on the resulting resin composition layer to produce a resin sheet. Specific drying conditions vary depending on the curability of the resin composition and the amount of organic solvent in the resin varnish, but for resin varnishes containing 30% to 60% by weight of organic solvent, drying can be performed at 80°C to 120°C for 3 to 13 minutes. The amount of the remaining organic solvent in the resin composition layer is preferably 5% by mass or less, and more preferably 2% by mass or less, of the total amount of the resin composition layer in order to prevent the organic solvent from diffusing in subsequent steps. Those skilled in the art can determine suitable drying conditions as appropriate through simple experiments.

[0158] In the photosensitive resin sheet set of the present invention, the thickness of the resin composition layer of the core resin sheet is preferably 0.5 μm or more, more preferably 1 μm or more, and even more preferably 3 μm or more, and is preferably 100 μm or less, more preferably 50 μm or less, and even more preferably 20 μm or less.

[0159] In the photosensitive resin sheet set of the present invention, the thickness of the resin composition layer of the cladding resin sheet is preferably 5 μm or more, more preferably 7 μm or more, and even more preferably 10 μm or more, and is preferably 100 μm or less, more preferably 50 μm or less, and even more preferably 30 μm or less, or 20 μm or less.

[0160] Examples of methods for applying the resin composition 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, spray coating, and dip coating.

[0161] The resin composition may be applied in several batches, in one batch, or by a combination of different methods. Among these, the die coating method is preferred because it provides excellent uniformity. To avoid contamination, it is preferable to carry out the application process in an environment where foreign matter is less likely to be generated, such as a clean room.

[0162] [Photosensitive resin ink set] As described above, the photosensitive resin composition set of the present invention may be used as a resin ink (resin varnish), and the present invention also provides such a resin ink set.

[0163] The photosensitive resin ink set of the present invention includes a core resin ink and a cladding resin ink. Here, the core resin ink can be prepared by adding an organic solvent to the core resin composition as needed, and the cladding resin ink can be prepared by adding an organic solvent to the cladding resin composition as needed. Hereinafter, the core resin ink and the cladding resin ink may be collectively referred to simply as "resin inks."

[0164] In the photosensitive resin ink set of the present invention, the content of organic solvent in the resin ink is preferably adjusted so that the amount of remaining organic solvent, measured according to the method described below in <Test Example 10: Analysis of organic solvent in resin composition layer by GC / MS (gas chromatography mass spectrometry)>, is preferably 5% by mass or less, more preferably 4% by mass or less, and even more preferably 3% by mass or less or 2.5% by mass or less. By adding organic solvent so that the amount of remaining organic solvent is the above-mentioned upper limit or less, it is possible to produce an optical waveguide in which the change in optical transmission loss before and after a reliability test is even smaller.

[0165] [Optical waveguide] An optical waveguide can be manufactured using the above-described photosensitive resin composition set, photosensitive resin sheet set, and photosensitive resin ink set. The present invention also provides such an optical waveguide. Hereinafter, an embodiment of the optical waveguide will be described with reference to the drawings.

[0166] FIG. 1 is a perspective view schematically illustrating an optical waveguide 10 according to one embodiment of the present invention. As shown in FIG. 1, the optical waveguide 10 includes a core layer 100 and a clad layer 200. The core layer 100 includes a cured product of a core resin composition from the photosensitive resin composition set of the present invention, and preferably includes only a cured product of a core resin composition from the photosensitive resin composition set of the present invention. The clad layer 200 includes a cured product of a clad resin composition from the photosensitive resin composition set of the present invention, and preferably includes only a cured product of a clad resin composition from the photosensitive resin composition set of the present invention.

[0167] The core layer 100 is provided in the clad layer 200. Thus, the core layer 100 is covered by the clad layer 200. Usually, the entire peripheral surface of the core layer 100 is covered by the clad layer 200. The core layer 100 and the clad layer 200 are in direct contact with each other without any other layer therebetween, and therefore, an interface 100I can be formed between the core layer 100 and the clad layer 200. Usually, the core layer 100 has a higher refractive index than the clad layer 200, and therefore, light (not shown) can be transmitted within the core layer 100 from one end (incident end) 100A of the core layer 100 to the other end (exit end) 100B.

[0168] The wavelength of light that can be transmitted through the optical waveguide 10 can be selected from a variety of wavelengths. For example, preferred wavelength ranges of the transmitted light can 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 wavelength range of the light transmitted through the optical transmission line 10 is preferably 1300 nm to 1320 nm.

[0169] The optical waveguide 10 may be a single-mode optical waveguide or a multi-mode optical waveguide, but is preferably a single-mode optical waveguide. In particular, the optical waveguide 10 is preferably a single-mode optical waveguide for light in the preferred wavelength range described above. For example, the optical waveguide 10 is preferably a single-mode optical waveguide for light of 1310 nm.

[0170] It is desirable to set the width L of the core layer 100 appropriately within a range that allows light transmission. A specific range of the line width L of the core layer 100 is preferably 0.5 μm or more, more preferably 1 μm or more, and even more preferably 2 μm or more, and is preferably 50 μm or less, more preferably 30 μm or less, and even more preferably 20 μm or less, 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 in the thickness direction.

[0171] It is desirable to set the spacing S of the core layers 100 appropriately within a range that allows light transmission. A specific range of the spacing S of the core layers 100 is preferably 50 μm or more, more preferably 70 μm or more, and even more preferably 100 μm or more, and is preferably 1000 μm or less, more preferably 500 μm or less, and even more preferably 300 μm or less. The spacing S of the core layers 100 corresponds to the spacing (space) between the core layers as viewed in the thickness direction.

[0172] It is desirable to set the thickness T of the core layer 100 appropriately within a range that allows light transmission. A specific range of the thickness T of the core layer 100 is preferably 0.5 μm or more, more preferably 1 μm or more, and even more preferably 2 μm or more, and is preferably 50 μm or less, more preferably 30 μm or less, and even more preferably 20 μm or less, or 10 μm or less.

[0173] The thickness of the cladding layer 200 is usually greater than the thickness 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, and even more preferably 10 μm or more, and is preferably 100 μm or less, more preferably 60 μm or less, and even more preferably 40 μm or less, or 30 μm or less.

[0174] The optical waveguide 10 may include any element other than the core layer 100 and the clad layer 200, as necessary. For example, the optical waveguide 10 may include a conductive layer (not shown) made of plating or the like on the core layer, and a substrate 300. In the optical waveguide 10 including the substrate 300, the clad layer 200 is usually provided on the substrate 300, and the core layer 100 is provided within the clad layer 200.

[0175] The substrate 300 may be a hard substrate such as a glass substrate, a metal substrate, a ceramic substrate, a wafer, or a circuit board. Examples of the wafer include semiconductor wafers such as silicon wafers, gallium arsenide (GaAs) wafers, indium phosphide (InP) wafers, gallium phosphide (GaP) wafers, gallium nitride (GaN) wafers, gallium telluride (GaTe) wafers, zinc selenium (ZnSe) wafers, and silicon carbide (SiC) wafers, or pseudo wafers. Examples of the pseudo wafer include a plate-shaped member including a molding resin and electronic components embedded in the molding resin. Examples of the circuit board include a glass epoxy substrate, a metal substrate, a polyester substrate, a polyimide substrate, a BT resin substrate, and a thermosetting polyphenylene ether substrate. Here, the circuit board refers to a substrate having a patterned conductor layer (circuit) formed on one or both sides of the above-mentioned substrate. Furthermore, the substrate 300 may be a film formed of a plastic material such as polyethylene terephthalate, polyimide, or polyester. Furthermore, a flexible circuit board may be employed as the substrate 300 .

[0176] The optical waveguide 10 may also include, as an optional element, a protective layer (not shown) that protects the core layer 100 and the cladding layer 200. For example, the protective layer may be provided so as to cover the surface of the cladding layer 200 opposite to the substrate 300.

[0177] [Method for manufacturing optical waveguides] The optical waveguide 10 can be produced using the photosensitive resin composition set of the present invention.

[0178] Hereinafter, an embodiment in which the component (A) contains the component (a1) (hereinafter also referred to as the "first embodiment"; core formation by alkaline development) and an embodiment in which the component (A) contains the component (a2) (hereinafter also referred to as the "second embodiment"; core formation by etching) will be described.

[0179] -First embodiment (forming a core layer by alkaline development)- In one embodiment, the resin composition in the photosensitive resin composition set of the present invention contains a carboxyl group-containing resin (a1) as component (A). The resin composition containing component (a1) is soluble in an alkaline developer and can be developed using an alkaline developer. Hereinafter, an embodiment in which a core layer is formed using alkaline development, i.e., a first embodiment, will be described.

[0180] In the first embodiment, the optical waveguide 10 is Step (I) of forming a first composition layer containing a cladding resin composition; Step (II) of curing the first composition layer; Step (III) of forming a second composition layer containing a core resin composition on the first composition layer; a step (IV) of exposing the second composition layer to light; a step (V) of subjecting the second composition layer to a development treatment; Step (VI) of curing the second composition layer; Step (VII) of forming a third composition layer containing a cladding resin composition on the second composition layer; Step (VIII) of curing the third composition layer; The method can be produced by a method comprising the steps of: (a) forming a conductor layer on the cladding layer after the step (VII), if necessary.

[0181] 2 is a schematic cross-sectional view illustrating step (I) of the method for manufacturing an optical waveguide according to the first embodiment. As shown in FIG. 2, the method for manufacturing an optical waveguide according to the first embodiment includes step (I) of forming a first composition layer 210 containing a cladding resin composition. In this embodiment, an example in which the first composition layer 210 is formed on a substrate 300 is shown and described.

[0182] There are no particular limitations on the method for forming the first composition layer 210. For example, the first composition layer 210 may be formed by applying a cladding resin composition onto the substrate 300. From the viewpoint of smooth application, a varnish-like cladding resin composition containing a solvent may be prepared, and the varnish-like cladding resin composition may be applied.

[0183] 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.

[0184] The cladding resin composition may be applied in one application or in multiple applications. It may also be applied by a combination of different application methods. To avoid contamination, it is preferable to apply the composition in an environment where foreign matter is unlikely to be generated, such as a clean room.

[0185] After application of the cladding resin composition, the first composition layer 210 may be dried, if necessary. Drying can be performed using a drying device such as a hot air oven or a far-infrared oven. Drying conditions are preferably set appropriately depending on the composition of the cladding resin composition. Specifically, the drying temperature is preferably 50°C or higher, more preferably 70°C or higher, and even more preferably 80°C or higher, and 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 higher, more preferably 60 seconds or higher, and even more preferably 120 seconds or higher, and preferably 60 minutes or shorter, more preferably 20 minutes or shorter, and even more preferably 5 minutes or shorter.

[0186] The first composition layer 210 may be formed using, for example, a clad resin sheet. Specifically, the first composition layer 210 can be formed on the substrate 300 by laminating the resin composition layer of the clad resin sheet onto the substrate 300. Lamination is typically performed by heating the resin composition layer of the clad resin sheet while pressing it onto the substrate 300. This lamination is preferably performed under reduced pressure by a vacuum lamination method. Furthermore, prior to lamination, a preheating treatment may be performed to heat the resin sheet and the substrate, if necessary.

[0187] The lamination conditions are, for example, a pressure bonding temperature (lamination temperature) of 70°C to 140°C and a pressure bonding pressure of 1 kgf / cm. 2 ~11kgf / cm 2 (9.8×10 4 N / m 2 ~107.9×10 4 N / m 2 ) and a pressure bonding time of 5 to 300 seconds. Furthermore, lamination is preferably carried out under reduced pressure with an air pressure of 20 mmHg (26.7 hPa) or less. Lamination may be carried out in a batch system or continuously using a roll.

[0188] The vacuum lamination method can be performed using a commercially available vacuum laminator, such as a vacuum applicator manufactured by Nikko Materials Co., Ltd., a vacuum pressure laminator manufactured by Meiki Seisakusho Co., Ltd., a roll-type dry coater manufactured by Hitachi Industries Co., Ltd., or a vacuum laminator manufactured by Hitachi AIC Corporation.

[0189] When the first composition layer 210 is formed using a clad resin sheet provided with a support, the support is usually peeled off at an appropriate time before the step (III).

[0190] The first composition layer 210 formed on the substrate 300 in step (I) usually contains a cladding resin composition, and preferably contains only a cladding resin composition.

[0191] The method for producing an optical waveguide according to the first embodiment includes, after step (I), step (II) of curing the first composition layer 210. In step (II), for example, the first composition layer 210 may be heat-treated. The conditions for the heat treatment may be selected depending on the type and amount of the resin component in the cladding resin composition, and may be 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 heat treatment is preferably carried out in an inert atmosphere such as a nitrogen atmosphere.

[0192] Alternatively, the first composition layer 210 may be cured by exposure treatment. In one example, the specific exposure dose range is preferably 10 mJ / cm 2 2 More preferably, 50 mJ / cm 2 More preferably, 200 mJ / cm 2 or more, preferably 10,000 mJ / cm 2 Less than or equal to 8,000 mJ / cm 2 or less, more preferably 4,000 mJ / cm 2 Below 3,000mJ / cm 2 Below 2,000mJ / cm 2 or less, or 1,000 mJ / cm 2 The first composition layer 210 may also be cured by a combination of exposure treatment and heat treatment.

[0193] When the first composition layer 210 is formed using a clad resin sheet having a support, in step (II), a support (not shown) may be present on the first composition layer 210. When a support is present on the first composition layer 210, exposure may be performed through the support, or exposure may be performed after peeling off the support.

[0194] 3 is a schematic cross-sectional view illustrating step (II) of the method for manufacturing an optical waveguide according to the first embodiment. By curing the first composition layer 210 in step (II), a cured first composition layer 220 is obtained on the substrate 300, as shown in FIG. 3. This cured first composition layer 220 forms a part of the cladding layer 200, and may be referred to as the "lower cladding layer" 220 hereinafter.

[0195] 4 is a schematic cross-sectional view illustrating step (III) of the method for producing an optical waveguide according to the first embodiment. The method for producing an optical waveguide according to the first embodiment includes, after step (III), step (III) of forming a second composition layer 110 containing a core resin composition on the lower clad layer 220 as the cured first composition layer, as shown in FIG.

[0196] There are no particular limitations on the method for forming the second composition layer 110. For example, the second composition layer 110 may be formed by applying a core resin composition onto the lower clad layer 220. From the viewpoint of smooth application, a varnish-like core resin composition containing a solvent may be prepared and then applied. The core resin composition may be applied in the same manner as the clad resin composition. After application of the core resin composition, the second composition layer 110 may be dried, if necessary. The second composition layer 110 may be dried using the same method and conditions as those for drying the first composition layer 210.

[0197] The second composition layer 110 may be formed, for example, using a core resin sheet. As a specific example, the resin composition layer of the core resin sheet is laminated onto the lower clad layer 220, thereby forming the second composition layer 110 on the lower clad layer 220. The core resin sheet can be laminated in the same manner as the clad resin sheet. The support for the core resin sheet is peeled off at an appropriate time before step (V).

[0198] The second composition layer 110 formed on the lower clad layer 220 in step (III) contains a core resin composition, and preferably contains only a core resin composition.

[0199] 5 is a schematic cross-sectional view illustrating step (IV) of the method for producing an optical waveguide according to embodiment 1. As shown in FIG. 5, the method for producing an optical waveguide according to embodiment 1 includes step (IV) of exposing the second composition layer 110 after step (III).

[0200] In step (IV), a latent image is formed in the second composition layer 110 by exposure treatment. Specifically, in the exposure treatment, light P is selectively irradiated onto specific portions of the second composition layer 110. Therefore, after the exposure treatment, the second composition layer 110 is provided with exposed portions 111 that have been irradiated with light and unexposed portions 112 that have not been irradiated with light. Typically, the core resin composition functions as a negative-type photosensitive resin composition, so that the exposed portions 111 form a latent image corresponding to the core layer.

[0201] From the viewpoint of performing selective exposure, the exposure treatment in step (IV) is usually performed using a mask 400. Specifically, in this exposure treatment, light P is irradiated onto the second composition layer 110 through the mask 400 having light-transmitting portions 410 and light-shielding portions 420. The light P passes through the light-transmitting portions 410 and enters the exposed portions 111, but cannot pass through the light-shielding portions 420 and therefore cannot enter the non-exposed portions 112. Thus, the exposed portions 111 and non-exposed portions 112 corresponding to the light-transmitting portions 410 and light-shielding portions 420 can be provided in the second composition layer 110. The mask 400 may be brought into close contact with the second composition layer 110 (contact exposure method) as shown in FIG. 5 , or exposure may be performed using parallel light without being in close 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 where the core layer is not present. Unless otherwise specified, the "planar shape" refers to the shape as viewed from the thickness direction. The light-transmitting portion 410 formed in a planar shape corresponding to the core layer may be referred to as a "mask pattern" hereinafter.

[0203] The light P used in the exposure treatment in step (IV) can be actinic rays in the same range as that used in the exposure treatment of the first composition layer 210 in step (II). The exposure dose of the light P is preferably set so that a desired core layer can be formed after curing in step (VII). In one example, the specific range of exposure dose in step (IV) can be the same range as that used for the exposure of the first composition layer 210 in step (II).

[0204] When the second composition layer 110 is formed using a core resin sheet having a support, in step (IV), a support (not shown) may be present on the second composition layer 110. When a support is present on the second composition layer 110, exposure may be performed through the support, or exposure may be performed after peeling off the support.

[0205] Because the core resin composition functions as a negative photosensitive resin composition, the solubility in the developer is reduced in the exposed areas 111. On the other hand, the solubility in the developer is high in the non-exposed areas 112. Utilizing this difference in solubility between the exposed areas 111 and the non-exposed areas 112, the subsequent development process in step (VI) is carried out.

[0206] The method for manufacturing an optical waveguide according to the first embodiment may include a step (X) of heating the second composition layer 110 after the step (IV) and before the step (V) in order to harden the second composition layer 110. The step (X) can quickly reduce the solubility of the exposed portion 111 in a developer. The heating in the step (X) may be performed using a hot plate or an oven. The heating temperature may be, for example, 40°C or higher and 110°C or lower. The heating time may be, for example, 30 seconds or higher and 60 minutes or lower.

[0207] FIG. 6 is a schematic cross-sectional view illustrating step (V) of the method for producing an optical waveguide according to the first embodiment. The method for producing an optical waveguide according to the first embodiment includes step (V) of subjecting the second composition layer 110 to a development treatment after step (IV). The development treatment allows the latent image formed in step (IV) to be developed. Because the core resin composition functions as a negative photosensitive resin composition, the development treatment does not remove the exposed portions 111, but removes the non-exposed portions 112 (see FIG. 5), as shown in FIG. 6. The exposed portions 111 of the second composition layer 110 remaining after development may have the same planar shape as the mask pattern of the light-transmitting portions 410 (see FIG. 5) of the mask 400 used in step (IV).

[0208] The development method is usually a wet development method in which the second composition layer 110 is brought into contact with a developer, and an alkaline aqueous solution is usually used as the developer.

[0209] Examples of alkaline aqueous solutions used as developers include aqueous solutions of alkali metal compounds. Examples of alkali metal compounds include alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, and potassium hydroxide; alkali metal carbonates or bicarbonates such as sodium carbonate and sodium bicarbonate; alkali metal phosphates such as sodium phosphate and potassium phosphate; and alkali metal pyrophosphates such as sodium pyrophosphate and potassium pyrophosphate. Examples of alkaline aqueous solutions include aqueous solutions of organic bases that do not contain metal ions, such as tetramethylammonium hydroxide. One type of alkaline aqueous solution may be used alone, or two or more types may be used in combination. Among these, aqueous solutions of organic bases that do not contain metal ions are preferred from the viewpoint of achieving the effects of the present invention more significantly.

[0210] The developer may contain additives such as surfactants and antifoaming agents, if necessary, to improve the developing action.

[0211] The development time is preferably 10 seconds to 5 minutes. The temperature of the developer during development is not particularly limited, but is preferably 20°C or higher and 50°C or lower, more preferably 40°C or lower.

[0212] Examples of development methods include puddle, spray, immersion, brushing, slapping, and ultrasonic methods. Among these, the spray method is suitable for improving resolution. When using the spray method, the spray pressure is preferably 0.05 MPa to 0.3 MPa.

[0213] After development using the developer, the second composition layer 110 may be further rinsed. Rinsing is preferably carried out with a solvent different from the developer. For example, rinsing may be carried out with the same type of solvent contained in the core resin composition or water. The rinsing time is preferably 5 seconds to 1 minute.

[0214] After development using a developer, a desmear treatment may be carried out to remove unexposed areas that cannot be completely removed by development. The desmear treatment may be carried out according to various methods known to those skilled in the art and used in the manufacture of printed wiring boards.

[0215] The method for producing an optical waveguide according to the first embodiment includes, after step (V), step (VI) of curing the second composition layer 110. This step (VI) typically includes heat-treating the second composition layer 110. The conditions for the heat treatment may be selected depending on the type and amount of the resin component in each resin composition in the photosensitive resin composition set of the present invention. For example, the conditions for the heat treatment in step (VI) may be the same as the conditions for the heat treatment of the first composition layer 210 in step (II).

[0216] 7 is a schematic cross-sectional view illustrating step (VI) of the method for producing an optical waveguide according to the first embodiment. By curing the second composition layer 110 in step (VI), a core layer 100 is obtained as a cured second composition layer on the lower cladding layer 220, as shown in FIG.

[0217] Fig. 8 is a schematic cross-sectional view illustrating step (VII) of the method for producing an optical waveguide according to the first embodiment. As shown in Fig. 9, the method for producing an optical waveguide according to the first embodiment includes, after step (VI), step (VII) of forming a third composition layer 230 containing a cladding resin composition on the core layer 100. The third composition layer 230 is usually formed so as to cover the entire peripheral surface of the core layer 100 that is not in contact with the lower cladding layer 220. Thus, the third composition layer 230 is formed so as to cover the core layer 100, and is also formed on the lower cladding layer 220.

[0218] There are no particular limitations on the method for forming the third composition layer 230. For example, the third composition layer 230 may be formed by applying a cladding resin composition onto the core layer 100 (and, if necessary, onto the lower cladding layer 220). The application of the cladding resin composition to form the third composition layer 230 may be carried out in the same manner as the application of the cladding resin composition to form the first composition layer 210. Furthermore, after application of the cladding resin composition, the third composition layer 230 may be dried, if necessary. The third composition layer 230 may be dried using the same method and conditions as those used to dry the first composition layer 210.

[0219] The third composition layer 230 may be formed using, for example, a clad resin sheet. As a specific example, the third composition layer 230 can be formed on the core layer 100 by laminating a resin composition layer of the clad resin sheet onto the core layer 100 (and, if necessary, the lower clad layer 220). The lamination of the clad resin sheet to form the third composition layer 230 can be performed in the same manner as the lamination of the clad resin sheet to form the first composition layer 210. When the third composition layer 230 is formed using a clad resin sheet provided with a support, the support may be peeled off in any step.

[0220] The third composition layer 230 formed on the core layer 100 in step (VIII) contains a cladding resin composition, and preferably contains only a cladding resin composition.

[0221] The method for manufacturing an optical waveguide according to the first embodiment includes, after step (VII), step (VIII) of curing the third composition layer 230. The curing of the third resin composition layer 230 in step (VIII) can usually be carried out in the same manner as the curing of the first composition layer 210.

[0222] 9 is a schematic cross-sectional view illustrating step (VIII) of the method for manufacturing an optical waveguide according to the first embodiment. By curing the third composition layer 230 in step (VIII), a cured third composition layer 240 is obtained on the core layer 100, as shown in FIG. 9. This cured third composition layer 240 forms a part of the cladding layer 200 and may be referred to as the "upper cladding layer" 240 hereinafter. The cladding layer 200 is formed from this upper cladding layer 240 and the lower cladding layer 220. Therefore, an optical waveguide 10 can be obtained, which includes the cladding layer 200 including the lower cladding layer 220 and the upper cladding layer 240, and the core layer 100 provided in this cladding layer 200.

[0223] FIG. 10 is a schematic cross-sectional view illustrating step (IX) of a method for producing an optical waveguide according to one embodiment of the present invention. The method for producing an optical waveguide according to one embodiment of the present invention may include step (IX) of forming a conductor layer on the clad layer after step (VIII). The conductor layer 500 formed on the upper clad layer 240 is preferably formed by plating. Furthermore, before forming the conductor layer 500 by plating, the surface of the upper clad layer 240 may be roughened. Since the upper clad layer 240 contains the photosensitive resin composition of the present invention, it is possible to improve the peel strength between the core layer 100 and the conductor layer 500 even if the arithmetic mean roughness (Ra) after the roughening treatment is small.

[0224] The procedure and conditions for the roughening treatment are not particularly limited. For example, the insulating layer can be roughened by carrying out a swelling treatment with a swelling liquid, a roughening treatment with an oxidizing agent, and a neutralization treatment with a neutralizing liquid in this order.

[0225] Examples of swelling solutions used in the roughening treatment include alkaline solutions and surfactant solutions, with alkaline solutions being preferred. Examples of alkaline solutions include sodium hydroxide solutions and potassium hydroxide solutions. Examples of commercially available swelling solutions include "Swelling Dip Securigance P" and "Swelling Dip Securigance SBU" manufactured by Atotech Japan. The swelling treatment using a swelling solution is not particularly limited, but can be carried out, for example, by immersing the insulating layer in a swelling solution at 30°C to 90°C for 1 to 20 minutes. From the viewpoint of suppressing swelling of the resin in the insulating layer to an appropriate level, it is preferable to immerse the insulating layer in a swelling solution at 40°C to 80°C for 5 to 15 minutes.

[0226] Examples of oxidizing agents used in the roughening treatment include alkaline permanganate solutions prepared by dissolving potassium permanganate or sodium permanganate in an aqueous solution of sodium hydroxide. Roughening treatment using an oxidizing agent such as alkaline permanganate solution is preferably carried out by immersing the insulating layer in an oxidizing agent solution heated to 60°C to 100°C for 10 to 30 minutes. The concentration of permanganate in the alkaline permanganate solution is preferably 5% by mass to 10% by mass. Commercially available oxidizing agents include alkaline permanganate solutions such as "Concentrate Compact CP" and "Dosing Solution Securigance P" manufactured by Atotech Japan.

[0227] The neutralizing solution used in the roughening treatment is preferably an acidic aqueous solution, and a commercially available product such as "Reduction Solution Securigant P" manufactured by Atotech Japan can be cited. Treatment with a neutralizing solution can be carried out by immersing the surface that has been roughened with an oxidizing agent in a neutralizing solution at 30°C to 80°C for 5 to 30 minutes. From the standpoint of workability, a preferred method is 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.

[0228] The arithmetic mean roughness Ra of the surface of the upper cladding layer after the roughening treatment is preferably 500 nm or less, more preferably less than 400 nm, even more preferably 200 nm or less, and 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.

[0229] After the roughening treatment is completed, the conductor layer 500 is formed on the roughened upper clad layer 240. Specifically, the surface of the core layer 100 can be plated by a method such as a semi-additive method or a full-additive method to form the conductor layer 500 having a desired wiring pattern. From the viewpoint of ease of manufacturing, it is preferable to form the conductor layer by a semi-additive method. An example of forming a conductor layer by a semi-additive method will be described below.

[0230] A plating seed layer is formed on the surface of the upper cladding layer 240 by electroless plating. Next, a mask pattern is formed on the formed plating seed layer, exposing a portion of the plating seed layer corresponding to the desired wiring pattern. After a metal layer is formed on the exposed plating seed layer by electrolytic plating, the mask pattern is removed. Thereafter, unnecessary plating seed layer is removed by etching or the like, thereby forming a conductor layer 500 having the desired wiring pattern.

[0231] The method for manufacturing the optical waveguide 10 may further include any optional steps in combination with the steps described above.

[0232] The method for manufacturing the optical waveguide 10 may include, for example, a step of forming a protective layer (not shown). The method for manufacturing the optical waveguide 10 may also include, for example, a step of dicing the manufactured optical waveguide 10.

[0233] The above-described steps may be repeated in the method for manufacturing the optical waveguide 10. For example, steps (I) to (IX) may be repeated to manufacture an optical waveguide having a multilayer structure in which core layers and clad layers are alternately provided on the substrate 300 in the thickness direction.

[0234] - Second embodiment (forming a core layer by etching) - In one embodiment, the resin composition in the photosensitive resin composition set of the present invention contains, as component (A), an epoxy group- and radically polymerizable group-containing resin (a2). The resin composition containing component (a2) can be patterned by etching. Hereinafter, an embodiment in which a core layer is formed using pattern formation by etching, i.e., a second embodiment, will be described.

[0235] In the second embodiment, the optical waveguide 10 is Step (i) of forming a first composition layer containing a cladding resin composition; (ii) curing the first composition layer; (iii) forming a second composition layer containing a core resin composition on the first composition layer; Step (iv) of curing the second composition layer; (v) forming a fourth composition layer containing a resist composition on the second composition layer; (vi) a step of exposing the fourth composition layer to light; (vii) subjecting the fourth composition layer to a development treatment; (viii) forming a pattern in the second composition layer; (x) forming a third composition layer containing a cladding resin composition on the second composition layer; Step (xi) of curing the third composition layer; It can be produced by a method comprising the steps of: If necessary, the method may include a step (ix) of removing the fourth composition layer after the step (viii) and before the step (x).If necessary, the method may include a step (xii) of forming a conductor layer on the clad layer after the step (xi).

[0236] In the second embodiment, step (i), step (ii), and step (iii) may be carried out in the same manner as step (I), step (II), and step (III) in the first embodiment, respectively.

[0237] In the method for producing an optical waveguide according to the second embodiment, in steps (iv) to (viii), the cured product of the core resin composition is etched through a photoresist (etching resist) to form a pattern.

[0238] In step (iv), the second composition layer is cured. Step (iv) may be performed by heat treatment or exposure treatment. The conditions for the heat treatment and exposure treatment may be selected depending on the type and amount of the resin component in the core resin composition. For example, the conditions for the heat treatment and exposure treatment in step (iv) may be the same as the conditions for the heat treatment and exposure treatment in step (II).

[0239] In step (v), a fourth composition layer containing a resist composition is formed on the second composition layer. As the resist composition, a composition containing a resin that can be developed with a developer such as an alkaline aqueous solution is preferably used. As the resist composition, a conventionally known material used as a photoresist may be used, such as an acrylic resin.

[0240] In step (v), the method for forming the fourth composition layer is not particularly limited. For example, the fourth composition layer may be formed by applying a resist composition onto the second composition layer. The application of the fourth composition layer may be carried out in the same manner as the application of the cladding resin composition for forming the first composition layer in step (I). After application of the resist composition, the fourth composition layer may be dried, if necessary. The drying method and conditions for the fourth composition layer may be the same as those for drying the first composition layer. The fourth composition layer may also be formed by laminating a dry film containing the resist composition. It is preferable that the lamination conditions for the dry film are appropriately set depending on the physical properties of the dry film.

[0241] In step (vi), the fourth composition layer is subjected to an exposure treatment, and then in step (vii), the fourth composition layer is subjected to a development treatment. These steps (vi) and (vii) can be performed appropriately depending on the composition of the resist composition used. For example, steps (vi) and (vii) can be performed in the same manner as steps (IV) and (V) in the first embodiment, respectively.

[0242] In the exposure treatment in step (vi), the fourth composition layer is irradiated with light through a mask having a light-transmitting portion and a light-shielding portion. The light passes through the light-transmitting portion and enters the fourth composition layer (exposed portion), but does not pass through the light-shielding portion and therefore does not enter the fourth composition layer (non-exposed portion). Thus, exposed portions and non-exposed portions corresponding to the light-transmitting and light-shielding portions of the mask can be provided in the fourth composition layer. The mask may be in close contact with the fourth composition layer (contact exposure method), or exposure may be performed using parallel light without being in close contact (non-contact exposure method), as in step (IV) in the first embodiment.

[0243] The development treatment in step (vii) does not remove the exposed portion of the fourth composition layer, but removes the unexposed portion of the fourth composition layer. The exposed portion of the fourth composition layer remaining after development has the same shape as the light-transmitting portion of the mask (mask pattern), and can function as a resist layer (hereinafter, sometimes referred to as a "resist pattern").

[0244] In step (viii), a pattern is formed in the second composition layer. In step (viii), etching is performed using the resist patterns formed in steps (vi) and (vii) as a mask, thereby forming a pattern corresponding to the core layer in the second composition layer. Such etching can be performed by known methods such as dry etching using plasma gas and wet etching using an etchant (etching solution), and dry etching using plasma gas is preferred.

[0245] The plasma treatment can be carried out by treating the surface of the second composition layer exposed through the resist pattern (fourth composition layer) with plasma generated by introducing a gas into a plasma generator. Examples of the method for generating plasma include microwave plasma, which generates plasma using microwaves, high-frequency plasma, atmospheric pressure plasma, and vacuum plasma, which are generated under vacuum. Vacuum plasma, which is generated under vacuum, is preferred.

[0246] The gas to be converted into plasma is not particularly limited, and may be, for example, a gas containing SF, Ar, O, etc. The time for the plasma treatment is not particularly limited, and is preferably set appropriately depending on the thickness of the second composition layer and the fourth composition layer.

[0247] When step (viii) is performed using a plasma gas, the resist pattern (fourth composition layer) may also be removed during the process of forming a pattern on the second composition layer. The fourth composition layer may not be completely removed and may remain on the second composition layer. In such cases, step (ix) of removing the fourth composition layer may be performed, as described above. It is preferable to appropriately select a method for removing the fourth composition layer depending on the composition of the resist composition contained in the fourth composition layer. For example, the fourth composition layer may be removed using an alkaline stripping solution such as a sodium hydroxide solution.

[0248] In the method for manufacturing an optical waveguide according to the second embodiment, steps (iv) to (viii) (including step (ix) as necessary) are carried out to obtain a core layer as a cured second composition layer on the lower clad layer.

[0249] Step (x) and step (xi) in the second embodiment may be carried out, for example, in the same manner as step (VII) and step (VIII) in the first embodiment, respectively.

[0250] [Opto-electric hybrid board and its manufacturing method] An opto-electrical hybrid board according to one embodiment of the present invention includes the optical waveguide described above. Typically, the opto-electrical hybrid board includes an optical waveguide and an electric circuit board. The electric circuit board may include electronic components and wiring connected to the electronic components. Examples of the electronic components include passive components such as capacitors, inductors, and resistors; and active components such as semiconductor chips. The optical waveguide and the wiring of the electric circuit board may be connected via an opto-electrical conversion element. The opto-electrical conversion element may include a combination of a light-emitting element (e.g., a surface-emitting light-emitting diode) capable of converting electricity to light and a light-receiving element (e.g., a photodiode) capable of converting light to electricity. Furthermore, the opto-electrical hybrid board may include an optical element such as a mirror for adjusting the optical path.

[0251] A preferred example of an opto-electrical hybrid substrate is one that includes a chip in which an optical integrated circuit is formed on a silicon wafer. This chip is expected to be put to practical use in the near future using silicon photonics, and is expected to be mounted, for example, in a semiconductor package. An opto-electrical hybrid substrate that includes this chip includes, for example, an electric circuit board, a chip mounted on the electric circuit board, and an optical waveguide. The optical waveguide can be used to connect the wiring of the electric circuit board to the chip or to connect multiple chips together.

[0252] Chips manufactured using silicon photonics generally use light with wavelengths of 1310 nm and 1550 nm, with 1310 nm being the most common (Sho Yoshida, Daisuke Suganuma, and Takaaki Ishigure, "Fabrication of Single-Mode Polymer Waveguides Using the Mosquito Method and Low Loss," 28th Spring Conference of the Japan Institute of Electronics Packaging, 2014). Therefore, it is preferable that the optical waveguide be capable of transmitting light with wavelengths of 1310 nm and 1550 nm or close to these wavelengths, and for example, it is preferable that the optical waveguide be capable of transmitting light with wavelengths of 1300 nm to 1320 nm. The optical waveguides according to the above-described embodiments are capable of transmitting light with these wavelengths.

[0253] Generally, between single mode and multimode, single mode can achieve faster transmission. Therefore, from the viewpoint of high-speed transmission, single mode optical waveguides are preferable as optical waveguides applied to opto-electrical hybrid circuits. In single mode optical waveguides, it is preferable that the width of the core layer is small. For example, it is preferable to form a core layer with a width of 10 μm or less, or 5 μm or less. Furthermore, optical waveguides having such a narrow core layer are preferable from the viewpoint of increasing the degree of freedom in package design when the optical waveguide is applied to a semiconductor package. According to the optical waveguides of the above-described embodiments, it is possible to reduce the width of the core layer as described above.

[0254] Since the opto-electric hybrid board includes the optical waveguide described above, the manufacturing method of the opto-electric hybrid board includes the same method as the manufacturing method of the optical waveguide. [Example]

[0255] The present invention will be described in more detail below with reference to examples, but is not limited to these examples. In the following description, "parts" and "%" representing amounts mean "parts by mass" and "% by mass", respectively, unless otherwise specified. Unless otherwise specified, the temperature conditions are room temperature (23°C), and unless otherwise specified, the pressure conditions are atmospheric pressure (1 atm).

[0256] <Example I: Example of Resin Sheet>

[0257] <Synthesis Example 1: Synthesis of Naphthol Aralkyl Skeleton-Containing Acid-Modified Epoxy Acrylate Resin> 325 parts of a naphthol aralkyl epoxy resin ("ESN-475V" manufactured by Nippon Steel Chemical & Material Co., Ltd.) with an epoxy equivalent of 330 g / eq. was placed in a flask equipped with a gas inlet tube, a stirrer, a condenser, and a thermometer. 340 parts of propylene glycol monomethyl ether was added and dissolved by heating. 0.46 parts of hydroquinone and 1 part of triphenylphosphine were then added. The mixture was heated to 95-105°C, and 72 parts of acrylic acid were slowly added dropwise and allowed to react for 16 hours. The reaction product was cooled to 80-90°C, and 130 parts of tetrahydrophthalic anhydride was added. The reaction was allowed to proceed for 8 hours and then cooled. The solvent was removed to obtain an acid-modified epoxy acrylate resin with an acid value of 90 mgKOH / g and a nonvolatile content of 70% by mass. The weight-average molecular weight (Mw) of the resulting acid-modified epoxy acrylate resin was 1,000.

[0258] <Production Example I-1: Production of Resin Sheet> (1) Preparation of a varnish-like resin composition The mixture consisted of 20 parts of the naphthol aralkyl skeleton-containing ester-type acid-modified epoxy acrylate resin obtained in Synthesis Example 1, 10 parts of a naphthol aralkyl skeleton epoxy resin ("ESN-475V" manufactured by Nippon Steel Chemical & Material Co., Ltd., epoxy equivalent: approximately 330 g / eq.), 5 parts of a naphthalene-type tetrafunctional epoxy resin ("HP-4710" manufactured by DIC Corporation, epoxy equivalent: approximately 170 g / eq.), 12.5 parts of a photocurable resin ("DPHA" manufactured by Nippon Kayaku Co., Ltd., dipentaerythritol hexaacrylate), and 12.5 parts of a photopolymerization initiator ("Omnirad" manufactured by IGM). A varnish-like resin composition was prepared by mixing 1.5 parts of an alkoxysilane compound ("KBM-403" manufactured by Shin-Etsu Chemical Co., Ltd.), 0.1 parts of a curing accelerator ("Curezol C11Z-A" manufactured by Shikoku Chemical Industry Co., Ltd., 2,4-diamino-6-[2'-undecylimidazolyl-(1')]-ethyl-s-triazine), 15 parts of methyl ethyl ketone, and 1.5 parts of propylene glycol monomethyl ether acetate using a high-speed rotary mixer.

[0259] (2) Manufacturing of resin sheets A polyethylene terephthalate film ("Lumirror T6AM" manufactured by Toray Industries, Inc., thickness 38 μm, softening point 130°C) was prepared as a support. The varnish-like resin composition prepared above was uniformly applied to the support using a die coater so that the thickness of the resin composition layer after drying would be 5 μm, 6.5 μm, 7 μm, 10 μm, 20 μm, or 50 μm. The resin composition layer was then dried at 80°C to 110°C (maximum temperature 110°C) for 7 minutes to form a resin composition layer. Next, a protective film (biaxially oriented polypropylene film, "MA-411" manufactured by Oji F-Tex Co., Ltd.) was placed on the surface of the resin composition layer and laminated at 80°C to produce a resin sheet with a three-layer structure of support / resin composition layer / protective film.

[0260] <Production Examples I-2 to I-14: Production of Resin Compositions and Resin Sheets> A resin composition was prepared in the same manner as in Production Example I-1, except that the components were mixed according to the formulation shown in Table 1, and a resin sheet was produced from the resin composition. In the table, the amount of each component is expressed in parts by mass, and represents the actual amount used. In Table 1, the meanings of abbreviations are as follows:

[0261] (A) Carboxyl group-containing resin "Synthesis Example 1": Naphthol aralkyl skeleton-containing acid-modified epoxy acrylate resin (acid value 90 mgKOH / g, Mw: 1,000) synthesized in Synthesis Example 1, non-volatile components 70% by mass

[0262] (B) Epoxy resin HP-4710: DIC Corporation, naphthalene-type tetrafunctional epoxy resin, epoxy equivalent weight approximately 170g / eq. ESN-475V: Manufactured by Nippon Steel Chemical & Material Co., Ltd., naphthol aralkyl epoxy resin, epoxy equivalent weight approximately 330g / eq.

[0263] (C) Photocurable resin "DPHA": Dipentaerythritol hexaacrylate, manufactured by Nippon Kayaku Co., Ltd.

[0264] (D) Photopolymerization initiator "Omnirad 379EG": 2-dimethylamino-2-(4-methyl-benzyl)-1-(4-morpholin-4-yl-phenyl)-butan-1-one, manufactured by IGM

[0265] (E) Alkoxysilane Compound "KBM-403": 3-glycidoxypropyltrimethoxysilane manufactured by Shin-Etsu Chemical Co., Ltd. "KBM-4803": 8-glycidoxyoctyltrimethoxysilane manufactured by Shin-Etsu Chemical Co., Ltd. "KBM-1003": Vinyltrimethoxysilane manufactured by Shin-Etsu Chemical Co., Ltd. "KBM-5803": 8-methacryloxyoctyltrimethoxysilane manufactured by Shin-Etsu Chemical Co., Ltd. "KBM-5103": 3-acryloxypropyltrimethoxysilane manufactured by Shin-Etsu Chemical Co., Ltd. "KBM-573": N-phenyl-3-aminopropyltrimethoxysilane manufactured by Shin-Etsu Chemical Co., Ltd.

[0266] (E') Silane Compound Having No Alkoxysilane Group "KF-105": Epoxy-modified silicone oil manufactured by Shin-Etsu Chemical Co., Ltd.

[0267] (F) Curing accelerator "C11Z-A": 2,4-diamino-6-[2'-undecylimidazolyl-(1')]-ethyl-s-triazine, manufactured by Shikoku Chemicals Corporation

[0268] (H) Organic solvent MEK: Methyl ethyl ketone "PGMEA": Propylene glycol monomethyl ether acetate

[0269] <Test Example 1: Measurement of refractive index of cured resin composition using resin sheet> The refractive index of the cured product of the resin composition used to produce the resin sheet was measured by the following method.

[0270] The protective film was peeled off from the resin sheet having a 6.5 μm-thick resin composition layer produced in each production example. The resin sheet was then laminated onto a 6-inch silicon wafer at 80°C, the support was peeled off, and a 6.5 μm-thick resin composition layer was formed on the silicon wafer. Thereafter, the resin composition layer was exposed to light at an optimum exposure dose of 5000 mJ using a projection exposure device (Ushio Inc.'s "UFX-2240"). After exposure, the resin composition layer was spray-developed with a 1.0 mass% aqueous solution of tetramethylammonium hydroxide at 23°C as a developer at a spray pressure of 0.1 MPa for 30 seconds. After spray development, the resin composition layer was sprayed with 3 J / cm 2 The sample was then subjected to ultraviolet irradiation at 190°C for 90 minutes in a nitrogen atmosphere to obtain a sample formed from a cured product of the resin composition. The refractive index n (1310 nm) of the obtained sample was measured at room temperature and atmospheric pressure using a 2010M type prism coupler (manufactured by Metricon) with a 1310 nm laser beam.

[0271] <Test Example 2: Measurement of shrinkage rate> The protective film was peeled off from the resin sheet having a 10 μm-thick resin composition layer produced in each production example. The resin sheet was placed on a 6-inch silicon wafer so that the resin composition layer was in contact with the silicon wafer, and laminated using a vacuum laminator ("VP160" manufactured by Nikko Materials Co., Ltd.). The lamination conditions were a vacuum time of 30 seconds, a pressure bonding temperature of 60°C, a pressure bonding pressure of 0.3 MPa, and a pressure application time of 30 seconds. The support was then peeled off to obtain a laminate A having a silicon wafer and a resin composition layer.

[0272] The resin composition layer of the obtained laminate A was exposed to ultraviolet light using a projection exposure device (Ushio Inc.'s "UFX-2240") with exposure energy such that the number of gloss-remaining steps of a 41-step tablet would be 8 to 10. The exposure was carried out using a quartz glass mask having a mask pattern capable of drawing multiple straight lines with a length of 5 cm and an L / S (line / space) of 5 μm / 100 μm. In the L / S of this quartz glass mask, the lines correspond to the width of the core layers, and the spaces correspond to the spacing between the core layers. After exposure, the sample was left to stand at room temperature for 30 minutes, and then the entire surface of the resin composition layer was spray-developed with a 1% by mass aqueous solution of sodium carbonate at 30°C as a developer at a spray pressure of 0.2 MPa for 1 minute. After spray development, a 2 J / cm 2 The wafer was cleaved in a direction perpendicular to the obtained core line, and the cross section at that time was observed under a microscope. The vertical and horizontal lengths of the rectangular core were measured to calculate the area α. The wafer was then placed in a clean oven, heated from room temperature to 190°C, and after reaching 190°C, heat treatment was carried out for 69 minutes to cure the resin composition layer. After the resin was cured, the same cross section was observed under a microscope, and the vertical and horizontal lengths of the rectangular core were measured to calculate the area β. The calculated areas α and β were used to calculate the shrinkage rate c (c = β / α).

[0273] The amounts of raw materials used in preparing the resin compositions of the respective production examples and the measurement results of the test examples are shown in Table 1 below.

[0274] [Table 1]

[0275] <Example I-1: Formation of optical waveguide> The sheets manufactured in Manufacturing Example I-1 and Manufacturing Example I-2 were prepared, and the resolution, adhesion to the substrate, and optical transmission loss were evaluated by the following methods.

[0276] <Test Example 3: Evaluation of resolution (narrow-wire waveguide formation ability)> A glass epoxy substrate (copper-clad laminate) with an 18 μm-thick copper layer was roughened with a surface treatment agent (CZ8100, manufactured by MEC Co., Ltd.) containing an organic acid to prepare a substrate. Next, the protective film was peeled off from the resin sheet with a 10 μm-thick resin composition layer manufactured in Manufacturing Example I-2. The resin sheet was placed on the copper-clad laminate so that the resin composition layer and the copper-clad laminate were in contact, and the laminate was laminated using a vacuum laminator ("VP160" manufactured by Nikko Materials Co., Ltd.). The lamination conditions were a vacuum time of 30 seconds, a pressure temperature of 60°C, a pressure of 0.3 MPa, and a pressure time of 30 seconds. The support was then peeled off, and the substrate was exposed to ultraviolet light using a projection exposure system ("Ushio Inc. UFX-2240" manufactured by Ushio Inc.) at an exposure energy sufficient to leave 8 glossy steps on a 41-step tablet. The exposure was performed without using a quartz glass mask. After exposure, the exposure was 2 J / cm. 2 The laminate was then placed in a clean oven, heated from room temperature to 190°C, and after reaching 190°C, heated for 90 minutes in a nitrogen atmosphere to cure the resin composition layer. A lower clad layer was formed by curing the resin composition layer, and an intermediate laminate B1 comprising a copper-clad laminate and a lower clad layer was obtained.

[0277] Next, the protective film was peeled off from the 5 μm-thick resin sheet produced in Production Example I-1. The resin sheet was placed on the lower clad layer so that the resin composition layer of the resin sheet and the lower clad layer of intermediate laminate B1 were in contact with each other. Lamination was performed using a vacuum laminator ("VP160" manufactured by Nikko Materials Co., Ltd.) to form a resin composition layer on the lower clad layer. The lamination conditions were a vacuum time of 30 seconds, a pressure bonding temperature of 60°C, a pressure bonding pressure of 0.3 MPa, and a pressure application time of 30 seconds. This resulted in laminate B2, which comprised a copper-clad laminate, a lower clad layer, and a resin sheet in this order. The support was then peeled off to expose the resin composition layer.

[0278] The resin composition layer of laminate B2 was exposed to ultraviolet light using a projection exposure device (Ushio Inc.'s "UFX-2240") with an exposure energy such that the number of gloss remaining steps on a 41-step tablet was 8. The exposure was carried out using a quartz glass mask having a mask pattern that drew straight lines with an L / S (line / space) of 5 μm / 5 μm. After exposure, the substrate was left to stand at room temperature for 30 minutes, and then the support was peeled off. The entire surface of the resin composition layer was spray-developed with a 1% by mass aqueous solution of sodium carbonate at 30°C as the developer at a spray pressure of 0.2 MPa for 1 minute. After spray development, the surface was exposed to 2 J / cm. 2 The sample was then subjected to ultraviolet irradiation at 190°C for 1 hour in a nitrogen atmosphere, thereby obtaining sample B3, which was provided in this order with a copper-clad laminate, a lower clad layer, and a 5 μm-thick line layer (a layer formed from the cured product of the resin composition).

[0279] In addition, the thickness of the resin sheet produced in Production Example I-1 was changed to 7 μm, and a quartz glass mask having a mask pattern that draws straight lines with an L / S (line / space) of 7 μm / 7 μm was used. The same operations as above were performed to obtain Sample B4, which included, in this order, a copper-clad laminate, a lower clad layer, and a 7 μm-thick line layer (a layer formed of a cured product of the resin composition). Furthermore, the thickness of the resin sheet produced in Production Example I-1 was changed to 50 μm, and a quartz glass mask having a mask pattern that draws straight lines with an L / S (line / space) of 50 μm / 50 μm was used. The same operations as above were performed to obtain Sample B5, which included, in this order, a copper-clad laminate, a lower clad layer, and a 50 μm-thick line layer (a layer formed of a cured product of the resin composition).

[0280] The obtained samples B3, B4, and B5 were observed with a scanning electron microscope (SEM) (magnification: 2000 times). The resolution was evaluated according to the following evaluation criteria: Line width refers to the width of the line layer.

[0281] Evaluation criteria "Good": A line having a line width of 5 μm at a thickness of 5 μm could be formed, a line having a line width of 7 μm at a thickness of 7 μm could be formed, and a line having a line width of 50 μm at a thickness of 50 μm could be formed. "△": A line having a line width of 5 μm at a thickness of 5 μm could not be formed, but either a line having a line width of 7 μm at a thickness of 7 μm, or a line having a line width of 50 μm at a thickness of 50 μm could be formed. "X": None of the following was achieved: a line having a line width of 5 μm at a thickness of 5 μm, a line having a line width of 7 μm at a thickness of 7 μm, or a line having a line width of 50 μm at a thickness of 50 μm.

[0282] <Test Example 4: Evaluation of adhesion to the substrate> A varnish-like resin composition was prepared using a high-speed rotary mixer by adding 60 parts of a cresol novolac skeleton-containing acid-modified epoxy acrylate resin ("CCR-1171H" manufactured by Nippon Kayaku Co., Ltd.), 20 parts of a biphenyl-type epoxy resin ("YX4000H" manufactured by Mitsubishi Chemical Corporation), 40 parts of a photocurable resin ("DPHA" manufactured by Nippon Kayaku Co., Ltd., dipentaerythritol hexaacrylate), 2.0 parts of a photopolymerization initiator ("Omnipol379" manufactured by IGM), 4.0 parts of melamine, 25 parts of barium sulfate ("Variace B-30" manufactured by Sakai Chemical Industry Co., Ltd.), and 2 parts of a green pigment ("CG5370" manufactured by Dainichiseika Color & Chemicals Co., Ltd.). Methyl ethyl ketone was then added to the mixture to adjust the nonvolatile component concentration to 60% by mass.

[0283] A polyethylene terephthalate film ("Lumirror T6AM" manufactured by Toray Industries, Inc., thickness 38 μm, softening point 130°C) was prepared as a support. The varnish-like resin composition prepared above was uniformly applied to the support using a die coater so that the thickness of the resin composition layer after drying would be 25 μm, and the resulting layer was dried at 75°C to 110°C for 10 minutes to form a resin composition layer. Through these operations, a resin sheet including a photosensitive solder resist layer was obtained.

[0284] A glass epoxy substrate (copper-clad laminate) with an 18 μm-thick copper layer was roughened with a surface treatment agent containing an organic acid (CZ8100, manufactured by MEC Co., Ltd.) to prepare the substrate. A resin sheet was placed on the copper-clad laminate so that the solder resist layer was in contact with the copper-clad laminate of the substrate, and the substrate was laminated using a vacuum laminator ("VP160" manufactured by Nikko Materials Co., Ltd.). The lamination conditions were a vacuum time of 30 seconds, a compression temperature of 60°C, a compression pressure of 0.3 MPa, and a pressure time of 30 seconds. The support was then peeled off, and the substrate was exposed to UV light using a projection exposure system ("Ushio Inc. UFX-2240" manufactured by Ushio Inc.) at an exposure energy sufficient to result in 8 glossy remaining steps on a 41-step tablet. The exposure was performed without using a quartz glass mask. After leaving the substrate at room temperature for 30 minutes after exposure, the photosensitive resin composition in the unexposed areas was spray-developed with a 1% by mass aqueous sodium carbonate solution at 30°C for 60 seconds, at a dose of 2 J / cm. 2 After that, the substrate was placed in a clean oven, heated from room temperature to 190°C, and after reaching 190°C, heat treatment was carried out for 90 minutes in a nitrogen atmosphere to harden the solder resist layer, thereby obtaining a substrate for evaluation C1.

[0285] The protective film was peeled off from the resin sheet having a 10 μm-thick resin composition layer produced in Production Example I-2. The resin sheet was placed on the solder resist layer so that the resin composition layer of the resin sheet contacted the solder resist layer of the base evaluation substrate C1, and laminated using a vacuum laminator ("VP160" manufactured by Nikko Materials Co., Ltd.). The lamination conditions were a vacuum time of 30 seconds, a pressure temperature of 60°C, a pressure of 0.3 MPa, and a pressure time of 30 seconds. The support was then peeled off, and ultraviolet light exposure was performed using a projection exposure device ("UFX-2240" manufactured by Ushio Inc.) at an exposure energy such that the number of glossy remaining steps of a 41-step tablet was 8. The exposure was performed without using a quartz glass mask. After exposure, the exposure was 2 J / cm. 2The substrate was then placed in a clean oven and heated from room temperature to 190°C. After reaching 190°C, it was subjected to a 90-minute heat treatment in a nitrogen atmosphere to harden the resin composition layer, yielding a substrate evaluation substrate C2. The substrate evaluation substrate C2 was then left for 100 hours under HAST conditions (130°C, 85% RH). The substrate was then returned to room temperature, and cross-cuts (1 mm-wide grid-shaped cuts) were made in the surface of the resin composition layer to check for chips in the resin composition layer.

[0286] A case where there was no peeling in the resin composition layer and the substrate and no chipping in the resin composition layer after cross-cutting was marked as "○", and a case where there was peeling at the interface between the resin composition layer and the substrate and chipping in the resin composition layer after cross-cutting was marked as "×".

[0287] <Test Example 5: Evaluation of the difference in shrinkage rate between the core layer and the clad layer> In each example and comparative example, the shrinkage ratio c of the core layer resin composition core and the shrinkage rate c of the resin composition for the cladding layer clad Calculate the difference between the absolute value d(d=|c clad -c core |) was calculated.

[0288] <Test Example 6: Measurement of optical transmission loss> (1-1. Formation of the lower cladding layer) A glass epoxy substrate (copper-clad laminate) with an 18 μm-thick copper layer was roughened with a surface treatment agent (CZ8100, manufactured by MEC Co., Ltd.) containing an organic acid to prepare a substrate. The protective film was peeled off from the resin sheet with a 10 μm-thick resin composition layer manufactured in Manufacturing Example I-2. The resin sheet was placed on the copper-clad laminate so that the resin composition layer of the resin sheet contacted the copper-clad laminate of the substrate, and laminated using a vacuum laminator ("VP160" manufactured by Nikko Materials Co., Ltd.). The lamination conditions were a vacuum time of 30 seconds, a pressure temperature of 60°C, a pressure of 0.3 MPa, and a pressure time of 30 seconds. The support was then peeled off, and the substrate was exposed to ultraviolet light using a projection exposure system ("Ushio Inc. UFX-2240" manufactured by Ushio Inc.) at an exposure energy sufficient to leave 8 glossy steps on a 41-step tablet. The exposure was performed without using a quartz glass mask. After exposure, the exposure was 2 J / cm. 2 The laminate was then placed in a clean oven, heated from room temperature to 190°C, and after reaching 190°C, heated for 90 minutes in a nitrogen atmosphere to cure the resin composition layer. A lower clad layer was formed by curing the resin composition layer, and an intermediate laminate D1 including a copper-clad laminate and a lower clad layer was obtained.

[0289] (1-2. Formation of the core layer) The protective film was peeled off from the resin sheet having a 5 μm-thick resin composition layer produced in Production Example I-1. A resin sheet was placed on the surface of the lower clad layer of intermediate laminate D1 so that the resin composition layer of the resin sheet contacted the lower clad layer of intermediate laminate D1, and laminated using a vacuum laminator (Nikko Materials Co., Ltd., "VP160"). The lamination conditions were a vacuum time of 30 seconds, a pressure temperature of 60°C, a pressure of 0.3 MPa, and a pressure time of 30 seconds. The support was then peeled off, and the sheet was exposed to UV light using a projection exposure system (Ushio Inc., "UFX-2240") at an exposure energy sufficient to produce 8 gloss-remaining steps on a 41-step tablet. The exposure was performed using a quartz glass mask with a mask pattern capable of drawing multiple straight lines 5 cm long with an L / S (line / space) ratio of 5 μm / 100 μm. In the L / S of this quartz glass mask, the lines correspond to the width of the core layers, and the spaces correspond to the spacing between the core layers. After exposure, the film was left to stand at room temperature for 30 minutes, and then the support was peeled off. The entire surface of the resin composition layer was spray-developed with a 1% by mass aqueous solution of tetramethylammonium at 23°C as a developer at a spray pressure of 0.2 MPa for 1 minute. After spray development, the film was sprayed with 2 J / cm 2 The laminate was then placed in a clean oven, heated from room temperature to 190°C, and after reaching 190°C, heated for 90 minutes in a nitrogen atmosphere to cure the resin composition layer. A core layer was formed by curing the resin composition layer, and an intermediate laminate D2 was obtained which included a copper-clad laminate, a lower clad layer, and a core layer in this order.

[0290] (1-3. Formation of upper cladding layer) The protective film was peeled off from the resin sheet having a 20 μm-thick resin composition layer produced in Production Example I-2. The resin sheet was placed on the core layer of intermediate laminate D2 so that the resin composition layer of the resin sheet was in contact with the core layer of intermediate laminate D2, and laminated using a batch-type vacuum pressure laminator (Nikko Materials Co., Ltd., two-stage build-up laminator, CVP700). The lamination conditions were a vacuum time of 30 seconds, a pressure temperature of 60°C, a pressure of 0.3 MPa, and a pressure time of 30 seconds. The support was then peeled off, and ultraviolet light exposure was performed using a projection exposure device (Ushio Inc., "UFX-2240") at an exposure energy sufficient to leave 8 glossy steps on a 41-step tablet. The exposure was performed without using a quartz glass mask. After exposure, the exposure was 2 J / cm. 2 The laminate was then placed in a clean oven, heated from room temperature to 170°C, and after reaching 170°C, heated for 60 minutes in a nitrogen atmosphere to cure the resin composition layer. An upper clad layer was formed by curing the resin composition layer, and a sample laminate D3 was obtained which included a copper-clad laminate, a lower clad layer, a core layer, and an upper clad layer in this order.

[0291] In this sample stack D3, the combination of the lower cladding layer and the upper cladding layer constituted the cladding layer. Thus, an optical waveguide was obtained that included the cladding layer and a core layer within the cladding layer. Furthermore, in this sample stack D3, the core layer had a 5 cm long linear pattern corresponding to the mask pattern of the quartz glass mask, and the width (line width) and spacing (space) of the core layer included in these patterns matched the width (line width) and spacing (space) of the mask pattern.

[0292] (2. Preparation of test board) From the sample laminate D3 produced by the above procedure, the portion where the core layer was formed, i.e., the core layer on which the 5 cm linear pattern was drawn and the surrounding clad layer, was cut out to obtain a test substrate D4 equipped with an optical transmission line. The cutting conditions were as follows: Dicing equipment: DAD3221 (Disco) Blade: ZH14-SD4000-VI-50 Spindle speed: 30K / min Cutting speed: 5mm / sec Blade height: 0.060mm Dicing tape: T-80W (Denka, 80um)

[0293] (3-1. Measuring the optical transmission loss of the calibration optical system) As described below, the transmission loss of an optical system configured by excluding the test substrate D4 and the light-collecting module from the optical system for measuring the transmission loss of the test substrate D4 was measured. That is, a light source (1310 nm light source, THORLABS "LPSC-1310-FC") and a photoreceiver (Keysight optical power meter "N7742") were connected via an optical fiber (input fiber) on a vibration-isolating table covered with a blackout curtain to obtain an optical system for calibration. The light source was turned on, and the intensity of the light entering the photoreceiver was measured with the photoreceiver, thereby measuring the loss of this optical system for calibration.

[0294] (3-2. Measurement of optical transmission loss) Test substrate D4 was placed on a vibration-isolating table covered with a blackout curtain. A focusing module (numerical aperture 0.18) was connected to one end (input end) of the optical waveguide of test substrate D4. A light source (1310 nm light source, THORLABS "LPSC-1310-FC") was then connected to the focusing module via an optical fiber (input fiber). Another focusing module (numerical aperture 0.18) was connected to the other end (output end) of the optical waveguide of test substrate D4. A light receiver (Keysight optical power meter "N7742") was then connected to the focusing module via an optical fiber (output fiber). This procedure resulted in an optical system in which light emitted from the light source passed through the optical fiber (input fiber), focusing module, optical waveguide, focusing module, and optical fiber (output fiber) in that order before entering the light receiver. Hereinafter, this optical system may be referred to as the "sample optical system." The light source was turned on and the intensity of the light that entered the receiver was measured by the receiver to measure the loss of the sample optical system.

[0295] The loss of the optical waveguide included in the test substrate D4 was determined by subtracting the loss of the calibration optical system from the loss of the sample optical system.

[0296] (3-3. Measurement of optical transmission loss (dB / cm) of optical waveguide before reliability test) After measuring the loss of the 5cm-long optical waveguide, the optical waveguide was cut to 4cm and the same measurement was performed. The optical waveguide was then cut to 3cm and the measurement was repeated, resulting in calculations of the measured values ​​for the 5cm-long optical waveguide, the 4cm-long optical waveguide, and the 3cm-long optical waveguide. 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 three coordinates representing the measurement results. An approximate line between these three points was calculated using the least squares method, and the slope of the approximate line was determined as the loss per unit distance of the optical waveguide (optical transmission loss). The calculated optical transmission loss values ​​were evaluated according to the following criteria.

[0297] Evaluation criteria "◎": Optical transmission loss is less than 0.4 dB / cm "Good": Optical transmission loss is 0.4 dB / cm or more and less than 0.5 dB / cm "△": Optical transmission loss value is 0.5 dB / cm or more and less than 1.0 dB / cm "X": Optical transmission loss is 1.0 dB / cm or more

[0298] (4. Measurement of optical transmission loss (dB / cm) of optical waveguide after damp heat resistance test (HAST test)) Separately from the test substrate D4 used above, test substrate D5 was prepared according to the same procedure. This test substrate D5 was left in a high-temperature, constant-humidity tester set at 130°C and 85% RH for 100 hours, and the transmission loss value after the heat and humidity test (HAST test) was calculated by performing the above-mentioned operations 3-1 to 3-3. Furthermore, the change rate (%) of the calculated optical transmission loss value after the heat resistance test (HAST test) from the optical transmission loss value before the test was calculated and evaluated according to the following evaluation criteria.

[0299] Evaluation criteria "◎": Change rate less than 20% "Good": Change rate is 20% or more but less than 30% "△": Change rate 30% or more but less than 50% "×": Change rate of 50% or more

[0300] <Test example 7: Mode confirmation> The photodetector was removed from test board D4 and an infrared camera (InGaAs camera with a 100x objective lens) was installed instead. The light source was turned on and the light emitted from the end of the optical fiber (output fiber) was photographed with the infrared camera. If only one circular light edge was observed, it was determined to be single mode. If multiple edges were observed, it was determined to be multimode.

[0301] <Examples I-2 to I-10 and Comparative Examples I-1 to I-3: Formation of Optical Waveguides> As shown in Table 2, optical waveguides were formed in the same manner as in Example I-1, except that the combination of the core resin composition and the clad resin composition was changed, and evaluations were carried out by the respective tests.

[0302] The combinations of core resin compositions and clad resin compositions used in each of the examples and comparative examples, and the evaluation results, are shown in Table 2. In Table 2 below, the meanings of the abbreviations are as follows: NA: Numerical aperture of the optical waveguide (Numerical aperture NA is a value expressed by the following formula (1))

[0303]

number

[0304] "S" in the Mode column: Single mode "M" in the Mode column: Multimode

[0305] [Table 2]

[0306] In each example, it was confirmed that even when component (F) was not contained, the same results as those in the above examples were obtained, although to a different extent.

[0307] Example II: Resin Ink

[0308] <Production Example II-1: Production of Resin Composition> Epoxy group and radical polymerizable group-containing resin (Daicel-Allnex Corporation "EBECRYL 3605", epoxy equivalent 450 g / eq., bisphenol A type epoxy half acrylate) 10 parts, naphthol aralkyl skeleton epoxy resin (Nippon Steel Chemical & Material Corporation "ESN-475V", epoxy equivalent approximately 330 g / eq.) 4 parts, naphthalene type epoxy resin (DIC Corporation "HP-4032SS", epoxy equivalent approximately 145 g / eq.) 1 part, alkylphenol type epoxy resin (DIC Corporation "HP-820", epoxy equivalent approximately 225 g / eq.) 3 parts, photocurable resin (Nippon Kayaku Co., Ltd. "DPHA", dipentaerythritol hexaacrylate) 10 parts, photopolymerization initiator (BASF "Irgacure" 0.1 parts of an alkoxysilane compound (manufactured by Shin-Etsu Chemical Co., Ltd., "KBM-403") were mixed together to prepare a resin composition (resin ink) using a high-speed rotary mixer.

[0309] <Production Examples II-2 to II-8: Production of Resin Compositions> A resin composition was prepared in the same manner as in Production Example II-1, except that the components were mixed according to the formulation shown in Table 3. In Table 3, the abbreviations have the following meanings.

[0310] (A) Resin containing epoxy groups and radically polymerizable groups EBECRYL 3605: Manufactured by Daicel-Allnex, bisphenol A epoxy half acrylate, epoxy equivalent weight 450g / eq.

[0311] (B) Epoxy resin HP-4032SS: DIC naphthalene-type epoxy resin, epoxy equivalent weight approximately 145g / eq. HP-820: DIC alkylphenol epoxy resin, epoxy equivalent weight approximately 225g / eq. ESN-475V: Manufactured by Nippon Steel Chemical & Material Co., Ltd., naphthol aralkyl epoxy resin, epoxy equivalent weight approximately 330g / eq.

[0312] (C) Photocurable resin "DPHA": Dipentaerythritol hexaacrylate, manufactured by Nippon Kayaku Co., Ltd.

[0313] (D) Photopolymerization initiator "Irgacure OXE-01": BASF, 2-(benzoyloxyimino)-1-[4-(phenylthio)phenyl]-1-octanone

[0314] (E) Alkoxysilane Compound "KBM-403": 3-glycidoxypropyltrimethoxysilane manufactured by Shin-Etsu Chemical Co., Ltd. "KBM-4803": 8-glycidoxyoctyltrimethoxysilane manufactured by Shin-Etsu Chemical Co., Ltd. "KBM-1003": Vinyltrimethoxysilane manufactured by Shin-Etsu Chemical Co., Ltd. "KBM-5803": 8-methacryloxyoctyltrimethoxysilane manufactured by Shin-Etsu Chemical Co., Ltd.

[0315] <Test Example 8: Measurement of refractive index of cured resin composition using resin ink> The refractive index of the cured resin composition using the resin ink was measured by the following method.

[0316] After adding 1.5 parts of propylene glycol monomethyl ether acetate to the resin ink produced in each production example, the resin ink was spin-coated onto a 6-inch silicon wafer and heated at 100°C for 3 minutes to form a resin composition layer with a thickness of 6.5 μm on the silicon wafer. Then, a current of 3 J / cm was applied to the resin composition layer. 2The sample was then placed in a clean oven and heated from room temperature to 190°C. After reaching 190°C, it was subjected to a heat treatment for 90 minutes in a nitrogen atmosphere to obtain a sample formed from a cured product of the resin composition. The refractive index n (1310 nm) of the obtained sample was measured at room temperature and atmospheric pressure using a 2010M type prism coupler (manufactured by Metricon) with a 1310 nm laser beam.

[0317] <Test Example 9: Measurement of shrinkage rate> After adding 1.5 parts of propylene glycol monomethyl ether acetate to the resin ink produced in each production example, the resin ink was spin-coated onto a 6-inch silicon wafer and heated at 100°C for 3 minutes to form a 10 μm-thick resin composition layer on the silicon wafer. 2The resin composition layer was then placed in a clean oven, heated from room temperature to 190°C, and heated for 90 minutes to cure the resin composition layer. A resist material (Tokyo Ohka Kogyo Co., Ltd., "THMR-iP5700HP") was then applied to the cured resin composition layer, and spin-coated at 1500 rpm for 30 seconds to form a 10 μm thick resist layer. The layer was then heated for 90 seconds on a hot plate heated to 110°C, and then exposed to UV light using a projection exposure system (Ushio Inc., "UFX-2240") with an exposure energy that resulted in 8 to 10 gloss-remaining steps on a 41-step tablet. The exposure was performed using a quartz glass mask with a mask pattern capable of drawing multiple straight lines with a length of 5 μm / 100 μm (L / S). In the L / S of this quartz glass mask, the lines correspond to the width of the core layers, and the spaces correspond to the spacing between the core layers. The wafer was then placed in a clean oven, heated from room temperature to 190°C, and after reaching 190°C, heat treatment was performed for 90 minutes in a nitrogen atmosphere to harden the resist layer. The resist layer was then developed to form a resist pattern, and the resist pattern and the resin composition layer exposed through the resist pattern were etched using a plasma device (Yamato Scientific Co., Ltd. "PR-200") to pattern the core layer. The wafer was cleaved in a direction perpendicular to the obtained core line, and the cross section at that time was observed under a microscope. The vertical and horizontal lengths of the rectangular core were measured to calculate the area α. The wafer was then placed in a clean oven, heated from room temperature to 190°C, and after reaching 190°C, heat treatment was performed for 69 minutes to harden the resin composition layer. After the resin was hardened, the same cross section was observed under a microscope, and the vertical and horizontal lengths of the rectangular core were measured to calculate the area β. Using the calculated areas α and β, the shrinkage rate (c) was calculated in the same manner as in Test Example 2.

[0318] Test Example 10: Analysis of organic solvent in resin composition layer by GC / MS (gas chromatography mass spectrometry) Five mg of each of the resin inks prepared in Production Examples II-1 to II-8 was weighed out and processed in a GCMS-QP2020-NX (Shimadzu Corporation) at 250°C for 10 minutes in an oven. The sample was then measured under conditions of a sample line temperature of 260°C, a transfer line temperature of 260°C, and a cycle time of 55 minutes. The solvent and volatile species were identified from each detected peak, and the content of organic solvents and volatile species in the sample was analyzed by comparing the results with a calibration curve prepared in advance.

[0319] <Test Example 11: Appearance after curing> 10 g of each of the resin inks prepared in Production Examples II-2 to II-5 and II-7 to II-8 was weighed out and placed in an aluminum cap and allowed to stand under vacuum. After confirming that all air bubbles had been removed, the ink was subjected to a vacuum of 2 J / cm. 2 The resulting cured product was then placed in a clean oven, heated from room temperature to 190°C, and after reaching 190°C, heated for 90 minutes in a nitrogen atmosphere to cure the photosensitive resin composition layer. The appearance of the resulting cured product was observed, and those with no bubbles were rated as ◯, and those with bubbles were rated as ×.

[0320] The amounts of raw materials used in preparing the resin compositions of each production example and the measurement results of the test examples are summarized in the following Table 3. In Table 3, the meanings of the abbreviations are as follows. Amount of remaining organic solvent (mass%): Amount of remaining organic solvent (mass%) measured in Test Example 10

[0321] [Table 3]

[0322] <Example II-1: Formation of optical waveguide> The resin inks prepared in Production Examples II-1 and II-2 were prepared, and the same procedures as in Test Examples 4 and 5 were carried out to evaluate the adhesion to the substrate and the difference in shrinkage rate. In addition, the optical transmission loss was evaluated by the following method.

[0323] <Test Example 12: Measurement of optical transmission loss> (1-1. Formation of the lower cladding layer) A glass epoxy substrate (copper-clad laminate) having a copper layer with a thickness of 18 μm was roughened with a surface treatment agent (CZ8100, manufactured by MEC Co., Ltd.) containing an organic acid to prepare a substrate. The resin composition produced in Production Example II-2 was uniformly applied to the copper-clad laminate of the substrate using a bar coater so that the resin composition layer had a thickness of 10 μm. Thereafter, a 2 J / cm 2 The laminate was then placed in a clean oven, heated from room temperature to 190°C, and heated for 90 minutes after reaching 190°C to cure the resin composition layer. A lower clad layer was formed by curing the resin composition layer, and an intermediate laminate E1 including a copper-clad laminate and a lower clad layer was obtained.

[0324] (1-2. Formation of the core layer) The resin composition produced in Production Example II-1 was applied onto the clad layer of the intermediate laminate E1 so that the thickness of the resin composition layer was 5 μm. 2The resin composition layer was then placed in a clean oven, heated from room temperature to 190°C, and heated for 90 minutes to harden the resin composition layer. A resist material (Tokyo Ohka Kogyo Co., Ltd., "THMR-iP5700HP") was then applied to the cured resin composition layer, and spin-coated at 1500 rpm for 30 seconds to form a 10 μm thick resist layer. The layer was then heated for 90 seconds on a hot plate heated to 110°C, and exposed to 250 mJ of ultraviolet light using a projection exposure system (Ushio Inc., "UFX-2240"). The exposure was performed using a quartz glass mask with a mask pattern capable of drawing multiple straight lines with a length of 5 cm and an L / S (line / space) of 5 μm / 100 μm. In the L / S of this quartz glass mask, the lines correspond to the width of the core layers, and the spaces correspond to the spacing between the core layers. The substrate was then placed in a clean oven and heated from room temperature to 190°C. After reaching 190°C, the resist layer was cured by heating for 90 minutes in a nitrogen atmosphere. The resist layer was then developed to form a resist pattern, and the resist pattern and the resin composition layer exposed through the resist pattern were etched using a plasma device (Yamato Scientific Co., Ltd. "PR-200") to pattern the core layer. The core layer was formed by etching, and an intermediate laminate E2 was obtained, which included a copper-clad laminate, a lower clad layer, and a core layer in this order.

[0325] (1-3. Formation of upper cladding layer) The resin composition produced in Production Example II-2 was applied onto the core layer of the intermediate laminate E2 so that the thickness of the resin composition layer was 10 μm. 2 The laminate was then placed in a clean oven, heated from room temperature to 190°C, and heated for 90 minutes after reaching 190°C to cure the resin composition layer. An upper clad layer was formed by curing the resin composition layer, and a sample laminate E3 was obtained which included a copper-clad laminate, a lower clad layer, a core layer, and an upper clad layer in this order.

[0326] In this sample stack E3, the combination of the lower cladding layer and the upper cladding layer constituted the cladding layer. Thus, an optical waveguide was obtained that included the cladding layer and a core layer within the cladding layer. Furthermore, in this sample stack E3, the core layer had a 5 cm long linear pattern that corresponded to the mask pattern of the quartz glass mask, and the width (line width) and spacing (space) of the core layer included in these patterns matched the width (line width) and spacing (space) of the mask pattern.

[0327] (2. Preparation of test board) Test substrate E4 was obtained by carrying out the same operation as in Test Example 6-2, except that sample laminate D3 was replaced with sample laminate E3.

[0328] (3. Measurement of optical transmission loss (dB / cm) of optical waveguide before testing) The optical transmission loss was measured in the same manner as in 3-1. to 3-3. of Test Example 6, except that Test Example D4 was changed to Test Example E4, and evaluation was performed using the same evaluation criteria as in Test Example 6.

[0329] (4. Measurement of optical transmission loss (dB / cm) of optical waveguide after reflow test) Separate from the sample laminate E4 used above, a test substrate E5 was prepared according to the same procedure. This test substrate E5 was subjected to five heat treatments using a reflow device (HAS-6116, manufactured by ANTOM) at 260°C or higher (heat history of 1 minute or more). The test substrate E5 after the treatment was subjected to the same operations as in 3-1 to 3-3 of Test Example 6, and the transmission loss value after the reflow test was calculated. Furthermore, the rate of change (%) of the calculated optical transmission loss value after the reflow test from the optical transmission loss value before the test was calculated and evaluated according to the following evaluation criteria.

[0330] Evaluation criteria "◎": Change rate less than 20% "Good": Change rate is 20% or more but less than 30% "△": Change rate 30% or more but less than 50% "×": Change rate of 50% or more

[0331] (5. Check the mode) The same operation as in Test Example 7 was performed on the test substrate E4, and the mode was confirmed using the same evaluation criteria as in Test Example 7.

[0332] <Examples II-2 to II-6 and Comparative Example I-1: Formation of Optical Waveguide> As shown in Table 4, optical waveguides were formed in the same manner as in Example II-1 except that the combination of the core resin composition and the clad resin composition was changed, and evaluations were carried out by the respective tests.

[0333] The combinations of core resin compositions and clad resin compositions used in each of the Examples and Comparative Examples, and the evaluation results, are shown in the following Table 4. In Table 4, the meanings of abbreviations are as follows. NA: Numerical aperture of the optical waveguide (Numerical aperture NA is a value expressed by the following formula (1))

[0334]

number

[0335] "S" in the Mode column: Single mode "M" in the Mode column: Multimode

[0336] [Table 4] [Explanation of symbols]

[0337] 10 Optical waveguide 100 Core Layer 110 Second composition layer 111 Exposure section 112 Unexposed area 200 cladding layers 210 First composition layer 220 Cured first composition layer (lower clad layer) 230 Third composition layer 240 Cured third composition layer (upper clad layer) 300 Base material 400 masks 410 Translucent part 420 Light blocking section 500 conductor layers

Claims

1. A photosensitive resin composition set including a core resin composition and a clad resin composition, The core resin composition and the clad resin composition each comprise: (A) a carboxyl group-containing resin (a1) or an epoxy group- and radically polymerizable group-containing resin (a2); (B) an epoxy resin; (C) a photocurable resin, and (D) Photopolymerization initiator Including, At least the cladding resin composition further comprises (E) an alkoxysilane compound having one or more functional groups selected from the group consisting of an epoxy group, a phenylamino group, a vinyl group, and a (meth)acryloyl group; Including, When the non-volatile components of the core resin composition are taken as 100% by mass, the content (% by mass) of the (E) component in the core resin composition is taken as (E)core, and when the non-volatile components of the clad resin composition are taken as 100% by mass, the content (% by mass) of the (E) component in the clad resin composition is taken as (E)clad, (E)core and (E)clad are 0.6≦(E)clad−(E)core≦10 A photosensitive resin composition set that satisfies the relationship of

2. The photosensitive resin composition set according to claim 1 , wherein the resin (a1) comprises at least one of an aralkyl resin and a cardo resin.

3. The photosensitive resin composition set according to claim 1 , wherein the resin (a2) contains a (meth)acryloyl group.

4. The photosensitive resin composition set according to claim 1, wherein (E) clad is 1 to 12 mass%.

5. When the content of the (C) component in the core resin composition is defined as (C)core when the non-volatile components of the core resin composition are taken as 100% by mass, and when the content of the (C) component in the clad resin composition is defined as (C)clad when the non-volatile components of the clad resin composition are taken as 100% by mass, (C)core and (C)clad are 0.9≦(C)clad / (C)core≦1.5 The photosensitive resin composition set according to claim 1 , wherein the following relationship is satisfied:

6. When the non-volatile components of the core resin composition are taken as 100% by mass, the contents of the (A) component and the (B) component in the core resin composition are taken as (A)core and (B)core, respectively, and the (A)core and the (B)core satisfy the following conditions: 0.1≦(A) core / (B) core≦5 The photosensitive resin composition set according to claim 1 , wherein the following relationship is satisfied:

7. When the content of the (A) component and the (B) component in the clad resin composition is defined as (A)clad and (B)clad, respectively, when the non-volatile components of the clad resin composition are taken as 100% by mass, (A)clad and (B)clad are: 0.1≦(A) clad / (B) clad≦5 The photosensitive resin composition set according to claim 1 , wherein the following relationship is satisfied:

8. When the non-volatile components of the core resin composition are taken as 100% by mass, the contents of the (A) component and the (C) component in the core resin composition are taken as (A)core and (C)core, respectively, and the (A)core and the (C)core satisfy the following conditions: 0.1≦(A)core / (C)core≦5 The photosensitive resin composition set according to claim 1 , wherein the following relationship is satisfied:

9. When the content of the (A) component and the (C) component in the clad resin composition is defined as (A)clad and (C)clad, respectively, when the non-volatile components of the clad resin composition are taken as 100% by mass, (A)clad and (C)clad are 0.1≦(A)clad / (C)clad≦5 The photosensitive resin composition set according to claim 1 , wherein the following relationship is satisfied:

10. The photosensitive resin composition set according to claim 1 , wherein each of the core resin composition and the clad resin composition further comprises (H) an organic solvent.

11. The photosensitive resin composition set according to claim 1, which is a photosensitive resin composition set for producing an optical waveguide.

12. The photosensitive resin composition set according to claim 1, which is a photosensitive resin composition set for producing an optical waveguide capable of transmitting light having a wavelength of 1300 nm to 1320 nm.

13. The photosensitive resin composition set according to claim 1, which is a photosensitive resin composition set for producing a single-mode optical waveguide.

14. A photosensitive resin sheet set including a core resin sheet and a clad resin sheet, The core resin sheet comprises a resin composition layer containing the core resin composition in the photosensitive resin composition set according to any one of claims 1 to 13, A photosensitive resin sheet set, wherein the clad resin sheet comprises a resin composition layer containing the clad resin composition in the photosensitive resin composition set according to any one of claims 1 to 13.

15. A photosensitive resin ink set including a core resin ink and a cladding resin ink, the core resin ink contains the core resin composition in the photosensitive resin composition set according to any one of claims 1 to 13, A photosensitive resin ink set, wherein the cladding resin ink comprises the cladding resin composition in the photosensitive resin composition set according to any one of claims 1 to 13.

16. An optical waveguide having a core layer and a clad layer, The core layer, (A) a carboxyl group-containing resin (a1) or an epoxy group- and radically polymerizable group-containing resin (a2); (B) an epoxy resin; (C) a photocurable resin, and (D) Photopolymerization initiator and (E) an alkoxysilane compound having one or more functional groups selected from the group consisting of an epoxy group, a phenylamino group, a vinyl group, and a (meth)acryloyl group; The core resin composition may contain a cured product of the core resin composition, The cladding layer is (A) a carboxyl group-containing resin (a1) or an epoxy group- and radically polymerizable group-containing resin (a2); (B) an epoxy resin; (C) photocurable resin, (D) a photopolymerization initiator, and (E) an alkoxysilane compound having one or more functional groups selected from the group consisting of an epoxy group, a phenylamino group, a vinyl group, and a (meth)acryloyl group; The present invention relates to a cured product of a resin composition for cladding, When the non-volatile components of the core resin composition are taken as 100% by mass, the content (% by mass) of the (E) component in the core resin composition is taken as (E)core, and when the non-volatile components of the clad resin composition are taken as 100% by mass, the content (% by mass) of the (E) component in the clad resin composition is taken as (E)clad, (E)core and (E)clad are 0.6≦(E)clad−(E)core≦10 An optical waveguide that satisfies the relationship:

17. An optical / electrical hybrid board comprising the optical waveguide according to claim 16.

18. forming a first composition layer containing a cladding resin composition; curing the first composition layer; forming a second composition layer containing a core resin composition on the first composition layer; a step of exposing the second composition layer to light; a step of subjecting the second composition layer to a development treatment; curing the second composition layer; forming a third composition layer containing a cladding resin composition on the second composition layer; and curing the third composition layer in this order, The core resin composition and the clad resin composition each comprise: (A) a carboxyl group-containing resin (a1), (B) an epoxy resin; (C) a photocurable resin, and (D) Photopolymerization initiator Including, At least the cladding resin composition further comprises (E) an alkoxysilane compound having one or more functional groups selected from the group consisting of an epoxy group, a phenylamino group, a vinyl group, and a (meth)acryloyl group; Including, When the non-volatile components of the core resin composition are taken as 100% by mass, the content (% by mass) of the (E) component in the core resin composition is taken as (E)core, and when the non-volatile components of the clad resin composition are taken as 100% by mass, the content (% by mass) of the (E) component in the clad resin composition is taken as (E)clad, (E)core and (E)clad are 0.6≦(E)clad−(E)core≦10 A method for manufacturing an optical waveguide that satisfies the relationship:

19. forming a first composition layer containing a cladding resin composition; curing the first composition layer; forming a second composition layer containing a core resin composition on the first composition layer; curing the second composition layer; forming a fourth composition layer containing a resist composition on the second composition layer; a step of exposing the fourth composition layer to light; a step of subjecting the fourth composition layer to a development treatment; forming a pattern in the second composition layer; forming a third composition layer containing a cladding resin composition on the second composition layer; and curing the third composition layer in this order, The core resin composition and the clad resin composition each comprise: (A) a resin (a2) containing an epoxy group and a radical polymerizable group, (B) an epoxy resin; (C) a photocurable resin, and (D) Photopolymerization initiator Including, At least the cladding resin composition further comprises (E) an alkoxysilane compound having one or more functional groups selected from the group consisting of an epoxy group, a phenylamino group, a vinyl group, and a (meth)acryloyl group; Including, When the non-volatile components of the core resin composition are taken as 100% by mass, the content (% by mass) of the (E) component in the core resin composition is taken as (E)core, and when the non-volatile components of the clad resin composition are taken as 100% by mass, the content (% by mass) of the (E) component in the clad resin composition is taken as (E)clad, (E)core and (E)clad are 0.6≦(E)clad−(E)core≦10 A method for manufacturing an optical waveguide that satisfies the relationship:

20. forming a first composition layer containing a cladding resin composition; curing the first composition layer; forming a second composition layer containing a core resin composition on the first composition layer; a step of exposing the second composition layer to light; a step of subjecting the second composition layer to a development treatment; curing the second composition layer; forming a third composition layer containing a cladding resin composition on the second composition layer; and curing the third composition layer in this order, The core resin composition and the clad resin composition each comprise: (A) a carboxyl group-containing resin (a1), (B) an epoxy resin; (C) a photocurable resin, and (D) Photopolymerization initiator Including, At least the cladding resin composition further comprises (E) an alkoxysilane compound having one or more functional groups selected from the group consisting of an epoxy group, a phenylamino group, a vinyl group, and a (meth)acryloyl group; Including, When the non-volatile components of the core resin composition are taken as 100% by mass, the content (% by mass) of the (E) component in the core resin composition is taken as (E)core, and when the non-volatile components of the clad resin composition are taken as 100% by mass, the content (% by mass) of the (E) component in the clad resin composition is taken as (E)clad, (E)core and (E)clad are 0.6≦(E)clad−(E)core≦10 A method for manufacturing an optical / electrical hybrid board that satisfies the above relationship.

21. forming a first composition layer containing a cladding resin composition; curing the first composition layer; forming a second composition layer containing a core resin composition on the first composition layer; curing the second composition layer; forming a fourth composition layer containing a resist composition on the second composition layer; a step of exposing the fourth composition layer to light; a step of subjecting the fourth composition layer to a development treatment; forming a pattern in the second composition layer; forming a third composition layer containing a cladding resin composition on the second composition layer; and curing the third composition layer in this order, The core resin composition and the clad resin composition each comprise: (A) a resin (a2) containing an epoxy group and a radical polymerizable group, (B) an epoxy resin; (C) a photocurable resin, and (D) Photopolymerization initiator Including, At least the cladding resin composition further comprises (E) an alkoxysilane compound having one or more functional groups selected from the group consisting of an epoxy group, a phenylamino group, a vinyl group, and a (meth)acryloyl group; Including, When the non-volatile components of the core resin composition are taken as 100% by mass, the content (% by mass) of the (E) component in the core resin composition is taken as (E)core, and when the non-volatile components of the clad resin composition are taken as 100% by mass, the content (% by mass) of the (E) component in the clad resin composition is taken as (E)clad, (E)core and (E)clad are 0.6≦(E)clad−(E)core≦10 A method for manufacturing an optical / electrical hybrid board that satisfies the above relationship.

Images