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 even when being exposed to high temperature environment.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, (B) an epoxy resin, (C) a photocurable resin, and (D) a photopolymerization initiator. At least the resin composition for the clad further contains (E) a compound having one or more monovalent groups including a specific structure in one molecule. 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, and further to a photosensitive resin sheet set, an optical waveguide, a method for producing an optical waveguide, an optical-electrical hybrid board, and a method for producing an optical-electrical hybrid board. [Background technology]

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

[0003] [Patent Document 1] JP 2019-211540 A [Patent Document 2] Patent No. 5771978 Summary of the Invention [Problem to be solved by the invention]

[0004] Especially in data centers where high-speed transmission is required, research into the introduction of silicon photonics is being actively conducted. 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 is expected to form an optical integrated circuit on a chip using a fine-wire waveguide. When manufacturing an optoelectronic hybrid board equipped with this chip, it is necessary to provide an optical waveguide on the optoelectronic hybrid board in order to extract the signal light from the fine-wire waveguide inside the chip to the outside of the chip and connect it to the wiring between the chips. Since this optoelectronic hybrid board is required to have the same reliability as a printed circuit board, it is desirable that there be no significant change in optical transmission loss even when exposed to a high-temperature environment.

[0006] The present invention has been devised in view of the above-mentioned problems, and has an object to provide a photosensitive resin composition set capable of producing an optical waveguide in which the change in optical transmission loss is small even when exposed to a high-temperature environment; a photosensitive resin sheet 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. [Means for solving the problem]

[0007] As a result of intensive research, the present inventors have found that the above-mentioned problems can be solved by using a combination of a core resin composition containing (A) a carboxyl group-containing resin, (B) an epoxy resin, (C) a photocurable resin, and (D) a photopolymerization initiator with a cladding resin composition containing (A) a carboxyl group-containing resin, (B) an epoxy resin, (C) a photocurable resin, (D) a photopolymerization initiator, and (E) a compound having a specific functional group, and by adjusting the content of component (E) so that the contents of component (E) in the core resin composition and the cladding resin composition satisfy a predetermined relationship, thereby completing the present invention. That is, the present invention includes the following.

[0008] <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 are each (A) a carboxyl group-containing resin, (B) epoxy resin, (C) a photocurable resin, and (D) Photopolymerization initiator Including, At least the cladding resin composition further comprises (E) A compound having, in one molecule, one or more groups selected from a monovalent group represented by the following formula (E1), a monovalent group represented by the following formula (E2), and a monovalent group represented by the following formula (E3), When the content (mass%) of the (E) component in the core resin composition is defined as (E)core when the non-volatile components of the core resin composition are taken as 100 mass%, and the content (mass%) of the (E) component in the clad resin composition is defined as (E)clad when the non-volatile components of the clad resin composition are taken as 100 mass%, (E)core and (E)clad are 0.6≦(E)clad-(E)core≦12 A photosensitive resin composition set that satisfies the above relationship. [ka] (In formula (E1), R S1 each independently represents a substituent, n1 represents an integer of 1 to 3; * indicates the binding site.) [ka] (In formula (E2), R 1 represents a hydrogen atom or a hydrocarbon group, R S2 each independently represents a substituent, n2 represents an integer of 0 to 5; * indicates the binding site.) [ka] (In formula (E3), X 1 represents a monovalent organic group. <2> The (A) component contains at least one of an aralkyl resin and a cardo resin. <1> The photosensitive resin composition set according to claim 1. <3> (E) clad is 1 to 13 mass%, <1> or <2> The photosensitive resin composition set according to claim 1. <4> When the content of the (C) component in the core resin composition is taken as 100% by mass of the non-volatile components of the core resin composition, the content of the (C) component in the clad resin composition is taken as (C)core, and when the content of the (C) component in the clad resin composition is taken as 100% by mass of the non-volatile components of the clad resin composition, the content of the (C) core and the (C) clad are 0.9≦(C)clad / (C)core≦1.5 Satisfy the relationship <1> ~ <3> 13. The photosensitive resin composition set according to claim 12. <5> 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. 0.1≦(A)core / (B)core≦5 Satisfy the relationship <1> ~ <4> 13. The photosensitive resin composition set according to claim 12. <6> When the non-volatile components of the clad resin composition are taken as 100 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 <1> ~ <5> 13. The photosensitive resin composition set according to claim 12. <7> 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. 0.1≦(A)core / (C)core≦5 Satisfy the relationship <1> ~ <6> 13. The photosensitive resin composition set according to claim 12. <8> When the non-volatile components of the clad resin composition are taken as 100 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 <1> ~ <7> 13. The photosensitive resin composition set according to claim 12. <9> A photosensitive resin composition set for producing an optical waveguide, <1> ~ <8> 13. The photosensitive resin composition set according to claim 12. <10> A photosensitive resin composition set for producing an optical waveguide capable of transmitting light having a wavelength of 1300 nm to 1320 nm. <1> ~ <9> 13. The photosensitive resin composition set according to claim 12. <11> A photosensitive resin composition set for producing a single-mode optical waveguide, <1> ~ <10> 13. The photosensitive resin composition set according to claim 12. <12> A photosensitive resin sheet set including a core resin sheet and a clad resin sheet, The core resin sheet is <1> ~ <11> A resin composition layer containing the core resin composition in the photosensitive resin composition set according to any one of the preceding claims, Cladding resin sheets, <1> ~ <11> 2. A photosensitive resin sheet set comprising a resin composition layer containing the cladding resin composition in the photosensitive resin composition set according to claim 1. <13> An optical waveguide having a core layer and a clad layer, The core layer is (A) a carboxyl group-containing resin, (B) epoxy resin, (C) a photocurable resin, and (D) Photopolymerization initiator and (E) A compound having one or more groups selected from a monovalent group represented by the following formula (E1), a monovalent group represented by the following formula (E2), and a monovalent group represented by the following formula (E3) in one molecule: The core resin composition may include a cured product of the core resin composition. The cladding layer is (A) a carboxyl group-containing resin, (B) epoxy resin, (C) Photocurable resin, (D) a photoinitiator, and (E) A compound having one or more groups selected from a monovalent group represented by the following formula (E1), a monovalent group represented by the following formula (E2), and a monovalent group represented by the following formula (E3) in one molecule: The present invention relates to a cured product of a cladding resin composition comprising the above-mentioned compound, When the content (mass%) of the (E) component in the core resin composition is defined as (E)core when the non-volatile components of the core resin composition are taken as 100 mass%, and the content (mass%) of the (E) component in the clad resin composition is defined as (E)clad when the non-volatile components of the clad resin composition are taken as 100 mass%, (E)core and (E)clad are 0.6≦(E)clad-(E)core≦12 An optical waveguide that satisfies the relationship: [ka] (In formula (E1), R S1 each independently represents a substituent, n1 represents an integer of 1 to 3; * indicates the binding site.) [ka] (In formula (E2), R 1 represents a hydrogen atom or a hydrocarbon group, R S2 each independently represents a substituent, n2 represents an integer of 0 to 5; * indicates the binding site.) [ka] (In formula (E3), X 1 represents a monovalent organic group. <14> <13> An optical / electrical hybrid board comprising the optical waveguide according to claim 1. <15> 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 subjecting the second composition layer to an exposure treatment; 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, (B) epoxy resin, (C) a photocurable resin, and (D) Photopolymerization initiator Including, At least the cladding resin composition further comprises (E) A compound having one or more groups selected from a monovalent group represented by the following formula (E1), a monovalent group represented by the following formula (E2), and a monovalent group represented by the following formula (E3) in one molecule: Including, When the content (mass%) of the (E) component in the core resin composition is defined as (E)core when the non-volatile components of the core resin composition are taken as 100 mass%, and the content (mass%) of the (E) component in the clad resin composition is defined as (E)clad when the non-volatile components of the clad resin composition are taken as 100 mass%, (E)core and (E)clad are 0.6≦(E)clad-(E)core≦12 A method for manufacturing an optical waveguide that satisfies the above relationship. [ka] (In formula (E1), RS1 each independently represents a substituent, n1 represents an integer of 1 to 3; * indicates the binding site.) [ka] (In formula (E2), R 1 represents a hydrogen atom or a hydrocarbon group, R S2 each independently represents a substituent, n2 represents an integer of 0 to 5; * indicates the binding site.) [ka] (In formula (E3), X 1 represents a monovalent organic group. <16> 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 subjecting the second composition layer to an exposure treatment; 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, (B) epoxy resin, (C) a photocurable resin, and (D) Photopolymerization initiator Including, At least the cladding resin composition further comprises (E) A compound having one or more groups selected from a monovalent group represented by the following formula (E1), a monovalent group represented by the following formula (E2), and a monovalent group represented by the following formula (E3) in one molecule: Including, When the content (mass%) of the (E) component in the core resin composition is defined as (E)core when the non-volatile components of the core resin composition are taken as 100 mass%, and the content (mass%) of the (E) component in the clad resin composition is defined as (E)clad when the non-volatile components of the clad resin composition are taken as 100 mass%, (E)core and (E)clad are 0.6≦(E)clad-(E)core≦12 A method for manufacturing an optical / electrical hybrid board that satisfies the above relationship. [ka] (In formula (E1), R S1 each independently represents a substituent, n1 represents an integer of 1 to 3; * indicates the binding site.) [ka] (In formula (E2), R 1 represents a hydrogen atom or a hydrocarbon group, R S2 each independently represents a substituent, n2 represents an integer of 0 to 5; * indicates the binding site.) [ka] (In formula (E3), X 1 represents a monovalent organic group. Effect of the Invention

[0009] According to the present invention, it is possible to provide a photosensitive resin composition set capable of producing an optical waveguide in which the change in optical transmission loss is small even when exposed to a high-temperature environment; a photosensitive resin sheet 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. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a perspective view showing a schematic configuration of an optical waveguide according to one embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic cross-sectional view for illustrating step (I) of the method for producing an optical waveguide according to one embodiment of the present invention. [Diagram 3] FIG. 3 is a schematic cross-sectional view for illustrating step (II) of the method for producing an optical waveguide according to one embodiment of the present invention. [Figure 4] FIG. 4 is a schematic cross-sectional view for illustrating step (III) of the method for producing an optical waveguide according to one embodiment of the present invention. [Diagram 5] FIG. 5 is a schematic cross-sectional view for illustrating step (IV) of the method for producing an optical waveguide according to one embodiment of the present invention. [Figure 6] FIG. 6 is a schematic cross-sectional view illustrating step (V) of the method for producing an optical waveguide according to one embodiment of the present invention. [Figure 7] FIG. 7 is a schematic cross-sectional view for illustrating step (VI) of the method for producing an optical waveguide according to one embodiment of the present invention. [Figure 8] FIG. 8 is a schematic cross-sectional view for explaining the step (VII) of the method for producing an optical waveguide according to one embodiment of the present invention. [Figure 9] FIG. 9 is a schematic cross-sectional view for explaining step (VIII) of the method for producing an optical waveguide according to one embodiment of the present invention. [Figure 10] FIG. 10 is a schematic cross-sectional view for explaining step (IX) of the method for producing an optical waveguide according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] <Terminology explanation> 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, the number of skeletal atoms of an organic group is preferably 1 to 50, more preferably 1 to 30, and even more preferably 1 to 20 or 1 to 10, unless otherwise specified. The number of skeletal atoms does not include the number of skeletal atoms of an epoxy group. Examples of organic groups include groups consisting of one or more skeletal atoms (including at least a carbon atom) selected from carbon atoms, oxygen atoms, nitrogen atoms, sulfur atoms, and silicon atoms.

[0012] In this specification, the term "aliphatic group" refers to a group obtained by removing one or more hydrogen atoms from an aliphatic compound. In particular, an n-valent aliphatic group (where n is an integer of 1 or more; the same applies below) refers to a group obtained by removing n hydrogen atoms 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. In this specification, the term "heteroatom" refers to an atom other than carbon and hydrogen atoms, and examples thereof include an oxygen atom, a nitrogen atom, a sulfur atom, a silicon atom, and a halogen atom.

[0013] In the present specification, the term "aliphatic hydrocarbon group" refers to a group in which one or more hydrogen atoms have been removed from an aliphatic compound that does not contain a heteroatom and is composed only of carbon atoms and hydrogen atoms. In particular, an n-valent aliphatic hydrocarbon group refers to a group in which n hydrogen atoms have been removed from an aliphatic compound that does not contain a heteroatom. Examples of the n-valent aliphatic hydrocarbon group include a group in which n hydrogen atoms have been removed from an aliphatic compound selected from the group consisting of an alkane that may have a substituent, an alkene that may have a substituent, an alkyne that may have a substituent, and an alkapolyene that may have a substituent (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). Here, any of the alkanes, alkenes, alkynes, and alkapolyenes may be linear or branched, and may contain a cyclic structure. In the present specification, the number of carbon atoms of the aliphatic hydrocarbon group is preferably 1 or more, more preferably 2 or more, or 3 or more, and is 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 substituents.

[0014] In the present specification, the term "heteroatom-containing aliphatic group" refers to a group in which one or more hydrogen atoms have been removed from an aliphatic compound containing a heteroatom. In particular, an n-valent heteroatom-containing aliphatic group refers to a group in which n hydrogen atoms have been removed from an aliphatic compound containing a heteroatom. In the "heteroatom-containing aliphatic group" in the present specification, 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 a carbon-carbon bond. In the "heteroatom-containing aliphatic group" in the present specification, the bond may extend from a carbon atom or from 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 the n-valent heteroatom-containing aliphatic group include a group in which n hydrogen atoms have been removed from an aliphatic compound containing a heteroatom selected from the group consisting of a heteroalkane which may have a substituent, a heteroalkene which may have a substituent, a heteroalkyne which may have a substituent, and a heteroalkapolyene which may have a substituent. 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, and may exist as a heteroatom such as -O-, -S-, and -N<, or 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 of these with -O- or -S- (wherein R' represents a hydrogen atom or a substituent described below. The same applies below). When the heteroatom-containing aliphatic group contains two or more heteroatoms, they may be the same or different from each other.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. The number of heteroatoms and the number of carbon atoms do not include the number of heteroatoms and the number of carbon atoms of a substituent.

[0015] In this specification, the term "aromatic group" refers to a group in which one or more hydrogen atoms have been removed from an aromatic compound. In particular, an n-valent aromatic group refers to a group in which n hydrogen atoms have been removed from an aromatic compound. Here, the aromatic compound may be a heteroatom-free aromatic compound composed only of carbon atoms and hydrogen atoms, or a heteroatom-containing aromatic compound composed of carbon atoms, hydrogen atoms, and heteroatoms. In this specification, the term "aromatic compound" refers to a compound containing an aromatic ring. In addition, in this specification, the term "aromatic ring" refers to a ring according to the Huckel rule in which the number of electrons contained in the π electron system on the ring is 4p+2 (p is a natural number), and includes a monocyclic aromatic ring and a fused polycyclic aromatic ring in which two or more monocyclic aromatic rings are fused. The aromatic ring may be an aromatic carbocycle having only carbon atoms as ring-constituting atoms, or an aromatic heterocycle having heteroatoms such as oxygen atoms, nitrogen atoms, and sulfur atoms as ring-constituting atoms in addition to carbon 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.

[0016] In this specification, 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. In particular, an n-valent aromatic hydrocarbon group refers to a group obtained by removing n hydrogen atoms from a heteroatom-free aromatic compound. In this specification, 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, 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 a substituent.

[0017] In this specification, 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. In detail, 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" in this specification, 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 a carbon-carbon bond. In addition, in the "heteroatom-containing aromatic group" in this specification, the bond may extend from a carbon atom or from a heteroatom. An example of an n-valent heteroatom-containing aromatic group is a group obtained by removing n hydrogen atoms from a heteroaryl compound that may have a substituent. 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 do not include the number of heteroatoms and the number of carbon atoms of substituents.

[0018] As used herein, the term "optionally substituted" in reference to a compound or group means both the case where none of the hydrogen atoms of the compound or group are substituted with a substituent, and the case where some or all of the hydrogen atoms of the compound or group are substituted with a substituent.

[0019] 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 (carboxy group), a sulfo group, a cyano group, a nitro group, a mercapto group, and an oxo group.

[0020] Examples of halogen atoms used as a substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. The alkyl group used as a substituent may be either linear or branched. The number of carbon atoms of the alkyl group is preferably 1 to 12, 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 number of carbon atoms of the alkenyl group or alkynyl group is preferably 2 to 12, more preferably 2 to 6, and even more preferably 2 to 4. 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, more preferably 2 to 4, and even more preferably 2. The number of carbon atoms of the alkapolyenyl group is preferably 3 to 20, more preferably 3 to 14, more preferably 3 to 12, and even more preferably 3 to 6. The number of carbon atoms of the cycloalkyl group or cycloalkenyl group used as a substituent is preferably 3 to 12, and more preferably 3 to 6. The alkoxy group used as a substituent may be either linear or branched. The number of carbon atoms in the alkoxy group is preferably 1 to 12, more preferably 1 to 6. The alkenyloxy group used as a substituent may be either linear or branched. The number of carbon atoms in the alkenyloxy group is preferably 2 to 12, more preferably 2 to 6, and even more preferably 2 to 4. The number of carbon atoms in the cycloalkyloxy group or cycloalkenyloxy group used as a substituent is preferably 3 to 12, more preferably 3 to 6. The alkylthio group used as a substituent may be either linear or branched. The number of carbon atoms in the alkylthio group is preferably 1 to 12, more preferably 1 to 6. The number of carbon atoms in the cycloalkylthio group used as a substituent is preferably 3 to 12, more preferably 3 to 6. The number of carbon atoms in the aryl group used as a substituent is preferably 6 to 14, more preferably 6 to 10. The number of carbon atoms in the aryloxy group used as a substituent is preferably 6 to 14, 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 refers to 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 refers to 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 represented by the formula: -C(=O)-R. S (wherein R S R is an alkyl group. S The alkyl group represented by the formula: may be either linear or branched. The number of carbon atoms in the acyl group is preferably 2 to 13, more preferably 2 to 7. The acyloxy group used as a substituent is represented by the formula: -OC(=O)-R S (wherein R S is as defined above). The number of carbon atoms in the acyloxy group is preferably 2 to 13, more preferably 2 to 7. The above-mentioned substituent may further have a substituent (sometimes referred to as a "secondary substituent"). As the secondary substituent, unless otherwise specified, the same as the above-mentioned substituent may be used.

[0021] 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] Hereinafter, the present invention will be described in detail with reference to embodiments and examples. However, the present invention is not limited to the following embodiments and examples, and may be modified and implemented as desired without departing from 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 the production of an optical waveguide including 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, Each of the core resin composition and the clad resin composition contains (A) a carboxyl group-containing resin, (B) an epoxy resin, (C) a photocurable resin, and (D) a photopolymerization initiator; At least the cladding resin composition further contains (E) a compound having one or more groups in one molecule selected from the group consisting of a monovalent group represented by the following formula (E1) (hereinafter also simply referred to as the "monovalent group E1"), a monovalent group represented by the following formula (E2) (hereinafter also simply referred to as the "monovalent group E2"), and a monovalent group represented by the following formula (E3) (hereinafter also simply referred to as the "monovalent group E3").

[0025] [ka]

[0026] (In formula (E1), R S1 each independently represents a substituent, n1 represents an integer of 1 to 3; * indicates the binding site.)

[0027] [ka]

[0028] (In formula (E2), R 1 represents a hydrogen atom or a hydrocarbon group, R S2 each independently represents a substituent, n2 represents an integer of 0 to 5; * indicates the binding site.)

[0029] [ka]

[0030] (In formula (E3), X 1 represents a monovalent organic group.

[0031] The photosensitive resin composition set of the present invention is characterized in that, when the content (% by mass) of the (E) component in the core resin composition is defined as (E)core when the non-volatile components of the core resin composition are taken as 100% by mass, and the content (% by mass) of the (E) component in the clad resin composition is defined as (E)clad when the non-volatile components of the clad resin composition are taken as 100% by mass, (E)core and (E)clad satisfy the relationship 0.6≦(E)clad-(E)core≦12.

[0032] According to the photosensitive resin composition set of the present invention, an optical waveguide can be produced in which the change in optical transmission loss is small even when exposed to a high-temperature environment. Also, according to the photosensitive resin composition set of the present invention, an optical waveguide can be produced in which the optical transmission loss value is small even after exposure to a high-temperature environment. Furthermore, the photosensitive resin composition set of the present invention usually has good resolution and can achieve good thin-line waveguide formability.

[0033] As described above, the core resin composition and the clad resin composition each contain (A) a carboxyl group-containing resin, (B) an epoxy resin, (C) a photocurable resin, and (D) a photopolymerization initiator, and at least the clad resin composition further contains (E) a compound having one or more groups selected from the monovalent group E1, the monovalent group E2, and the monovalent group E3 in one molecule. The core resin composition and the clad resin composition each contain each component so as to satisfy the relationship 0.6≦(E)clad-(E)core≦12. The core resin composition and the clad resin composition each may further contain optional components such as (F) a curing accelerator, (G) other additives, and (H) an organic solvent, as necessary. The components contained in the core resin composition and the clad resin composition will be described in detail below. Hereinafter, the core resin composition and the clad resin composition will be collectively referred to simply as "resin composition".

[0034] <(A) Carboxyl group-containing resin> In the photosensitive resin composition set of the present invention, the resin composition contains a carboxyl group (carboxy group)-containing resin as component (A).

[0035] The resin composition containing the component (A) is soluble in an alkaline developer (e.g., a 1% by mass aqueous solution of sodium carbonate) and can be developed in an alkaline state. The number of carboxyl groups per molecule of the component (A) may be one or more. The component (A) may be used alone or in combination of two or more.

[0036] The component (A) is not limited as long as it is capable of alkaline development, but it is preferable that the component (A) further contains a radical polymerizable group. Examples of the radical polymerizable group include unsaturated hydrocarbon groups such as vinyl, allyl, 1-propenyl, 3-cyclohexenyl, 3-cyclopentenyl, 2-vinylphenyl, 3-vinylphenyl, and 4-vinylphenyl groups; and α,β-unsaturated carbonyl groups such as (meth)acryloyl and maleimide groups (2,5-dihydro-2,5-dioxo-1H-pyrrol-1-yl groups).

[0037] When the (A) component contains a radical polymerizable group, photoradical polymerization is possible. In particular, the (A) component preferably contains a (meth)acryloyl group from the viewpoint of the reactivity of photoradical polymerization. The number of radical polymerizable groups per molecule of the (A) component may be one or may be two or more. In addition, when the (A) component contains two or more radical polymerizable groups per molecule, the radical polymerizable groups may be the same or different.

[0038] The component (A) is preferably a resin that has both a radically polymerizable group and a carboxyl group, and that allows for photoradical polymerization as well as alkaline development.

[0039] In one embodiment, the component (A) preferably contains an aromatic skeleton. Here, the 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 enjoy the effects of the present invention more preferably contains one or more aromatic skeletons selected from an aralkyl skeleton and a cardo skeleton. That is, in one embodiment, the component (A) contains one or more of an aralkyl type resin and a cardo type resin.

[0040] Examples of the aralkyl skeleton include a naphthol aralkyl skeleton, a phenol aralkyl skeleton, and a biphenyl aralkyl skeleton. Among them, the naphthol aralkyl skeleton is preferable from the viewpoint of obtaining the effects of the present invention. Therefore, in one embodiment, the component (A) contains a naphthol aralkyl resin as the aralkyl resin.

[0041] The cardo skeleton is a ring structure A 1 A carbon atom that is composed of two ring structures A 2 , and A 3 refers to a skeleton in which

[0042] [ka]

[0043] (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.

[0044] 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.

[0045] Examples of the aliphatic 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.

[0046] 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 further include those having a substituent.

[0047] 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 3When is an aliphatic ring or an aliphatic ring condensed with an aromatic ring, the ring structure is, for example, ring A 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.

[0048] 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 preferable, 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 preferable.

[0049] When component (A) contains a cardo skeleton (i.e., when it 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), in which * represents a bonding site.

[0050] [ka]

[0051] In a preferred embodiment, component (A) includes an acid-modified epoxy (meth)acrylate resin.

[0052] The acid-modified epoxy (meth)acrylate resin can be produced by acid-modifying an epoxy (meth)acrylate resin by a known method. The epoxy (meth)acrylate resin can be produced, for example, by reacting an epoxy resin with (meth)acrylic acid.

[0053] 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 functional groups; biphenol type epoxy resins such as biphenol type epoxy resin and tetramethylbiphenol type; 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, naphthol aralkyl type epoxy resin, etc. epoxy resins having 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 having a 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, copolymers of glycidyl methacrylate and acrylic esters;fluorene type epoxy resins;cardo skeleton-containing epoxy resins;Halogenated epoxy resins and the like.

[0054] The epoxy resin for producing the epoxy (meth)acrylate resin preferably contains an aromatic skeleton. The aromatic skeleton is as described above, and is preferably at least one selected from an aralkyl skeleton and a cardo skeleton. Thus, in one embodiment, the epoxy resin for producing the epoxy (meth)acrylate resin contains at least one selected from the group consisting of an aralkyl skeleton-containing epoxy resin (preferably a naphthol aralkyl type epoxy resin) and a cardo skeleton-containing epoxy resin.

[0055] 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 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 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.

[0056] 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.

[0057] Examples of the acid anhydride 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.

[0058] The acid-modified epoxy (meth)acrylate resin can be synthesized by a known method, but a commercially available product 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), "ZCR-1797H" (biphenyl skeleton-containing acid-modified epoxy acrylate), 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 of which are manufactured by Nippon Kayaku Co., Ltd. Resin), Showa Denko's "PR-300CP" (cresol novolac type acid modified epoxy acrylate resin), Nippon Kayaku's "CCR-1179" (cresol novolac skeleton-containing epoxy acrylate resin), ADEKA's "WR-301" (cardo skeleton-containing acid modified epoxy acrylate), Nippon Steel Chemical & Material's "V-259ME" (cardo skeleton-containing acid modified epoxy acrylate), Osaka Gas Chemical's "Oxol CR-TR1", "Oxol CR-TR2", "Oxol CR-TR3", "Oxol CR-TR4", "Oxol CR-TR5", "Oxol CR-TR6" (cardo skeleton-containing acid modified epoxy acrylate), etc. These may be used alone or in combination of two or more.

[0059] 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.

[0060] Examples of the diisocyanate compound 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 cyanide diisocyanate, N-acyl diisocyanate, trimethylhexamethylene diisocyanate, and 1,3-bis(isocyanate methyl)cyclohexane.

[0061] Examples of the carboxy group-containing diol compound include dimethylolpropionic acid, dimethylolbutanoic acid, and dimethylolnonanoic acid.

[0062] 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.

[0063] From the viewpoint of improving the alkaline developability of the resin composition, the acid value of the component (A) 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, even 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 the insulation reliability, the upper limit of the acid value of the component (A) 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.

[0064] The weight average molecular weight (Mw) of component (A) is preferably at least 500, more preferably at least 750, and even more preferably at least 900. The upper limit of Mw of component (A) 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).

[0065] In the photosensitive resin composition set of the present invention, the content of the component (A) in the resin composition is not particularly limited, but when the non-volatile components in the resin composition are taken as 100 mass%, it is preferably 10 mass% or more, more preferably 15 mass% or more, even more preferably 16 mass% or more, 18 mass% or more, or 20 mass% or more, and the upper limit is preferably 50 mass% or less, more preferably 40 mass% or less, even more preferably 35 mass% or less, 34 mass% or less, 32 mass% or less, or 30 mass% or less.

[0066] In the present invention, the content of each component in the core resin composition is a value when the non-volatile components in the core resin composition are 100 mass %, unless otherwise specified, and the content of each component in the clad resin composition is a value when the non-volatile components in the clad resin composition are 100 mass %, unless otherwise specified. The non-volatile components refer to all non-volatile components in the resin composition excluding the solvent.

[0067] <(B) Epoxy resin> In the photosensitive resin composition set of the present invention, the resin composition contains an epoxy resin as component (B). The component (B) may be used alone or in combination of two or more. Note that the component (B) does not include those that correspond to the above-mentioned component (A).

[0068] Examples of the (B) component 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, cyclohexane dimethanol 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, and examples thereof include bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, and bisphenol AF type epoxy resins. The 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 biphenyl aralkyl type epoxy resins are also included in the biphenyl type epoxy resins.

[0069] The component (B) preferably contains an epoxy resin having two or more epoxy groups in one molecule. The proportion of the epoxy resin having two or more epoxy groups in one molecule relative to 100% by mass of the 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.

[0070] The component (B) includes an epoxy resin that is liquid at a temperature of 20° C. (hereinafter sometimes referred to as a "liquid epoxy resin") and an epoxy resin that is solid at a temperature of 20° C. (hereinafter sometimes referred to as a "solid epoxy resin"). In the photosensitive resin composition set of the present invention, the resin composition may contain only a liquid epoxy resin as the component (B), or may contain 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 contains only a solid epoxy resin or both a liquid epoxy resin and a solid epoxy resin.

[0071] The liquid epoxy resin is preferably a liquid epoxy resin having two or more epoxy groups in one molecule.

[0072] As the liquid epoxy resin, glycirol type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AF type epoxy resin, naphthalene type epoxy resin, glycidyl ester type epoxy resin, glycidyl amine type epoxy resin, phenol novolac type epoxy resin, alicyclic epoxy resin having an ester skeleton, cyclohexane dimethanol type epoxy resin, cyclic aliphatic glycidyl ether, and epoxy resin having a butadiene structure are preferred.

[0073] 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 resin) manufactured by DIC Corporation; and "jER807" and "1750" (bisphenol A type epoxy resins) manufactured by Mitsubishi Chemical Corporation. F type epoxy resin); Mitsubishi Chemical's "jER152" (phenol novolac type epoxy resin); Mitsubishi Chemical's "630", "630LSD", and "604" (glycidylamine type epoxy resin); ADEKA's "ED-523T" (glycirol type epoxy resin); ADEKA's "EP-3950L", "EP-3980S" (glycidylamine type epoxy resin); ADEKA's "EP-4088S" (dicyclopentadiene type epoxy resin); Nippon Steel Chemical & "ZX1059" manufactured by Materials 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 ester skeleton); "PB-3600" manufactured by Daicel Corporation, "JP-100" and "J" manufactured by Nippon Soda Co., Ltd. Examples of epoxy resins that can be used include "P-200" (epoxy resin having a butadiene structure); "ZX1658" and "ZX1658GS" (liquid 1,4-glycidylcyclohexane type epoxy resin) manufactured by Nippon Steel Chemical & Material Co., Ltd.; "EG-280" (epoxy resin containing a fluorene structure) manufactured by Osaka Gas Chemical Co., Ltd.; "Oxol EG-200" and "Oxol EG-280" (epoxy resin containing a cardo structure) manufactured by Osaka Gas Chemical Co., Ltd.; and "EX-201" (cyclic aliphatic glycidyl ether) manufactured by Nagase ChemteX Corporation.

[0074] As the solid epoxy resin, a solid epoxy resin having three or more epoxy groups in one molecule is preferable, and an aromatic solid epoxy resin having three or more epoxy groups in one molecule is more preferable.

[0075] 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.

[0076] 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 Steel Chemical & Material Co., Ltd.; "ESN475V", 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", "YL7890" (bixylenol type epoxy resin) manufactured by Mitsubishi Chemical Co., Ltd.; "YL6121" (biphenyl type epoxy resin) manufactured by Mitsubishi Chemical Co., Ltd.; "YX8800" (anthracene type epoxy resin) manufactured by Mitsubishi Chemical Co., Ltd.; Mitsubishi Chemical "YX7700" (phenol aralkyl type epoxy resin) manufactured by Osaka Gas Chemicals; "PG-100" and "CG-500" manufactured by Osaka Gas Chemicals; "YL7760" (bisphenol AF type epoxy resin) manufactured by Mitsubishi Chemical; "YL7800" (fluorene type epoxy resin) manufactured by Mitsubishi Chemical; "jER1010" (bisphenol A type epoxy resin) manufactured by Mitsubishi Chemical; "jER1031S" (tetraphenylethane type epoxy resin) manufactured by Mitsubishi Chemical; "WHR991S" (phenolphthalimidine type epoxy resin) manufactured by Nippon Kayaku;Examples include "Ogusol PG-100" and "Ogusol CG-500" (epoxy resins containing cardo structure) manufactured by Osaka Gas Chemicals Co., Ltd.;

[0077] In one embodiment, the component (B) preferably contains an epoxy resin having an aromatic skeleton, more preferably contains an epoxy resin having a polycyclic aromatic skeleton containing a condensed ring, and further preferably contains 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 naphthol aralkyl skeletons, naphthol novolac skeletons, naphthalene skeletons, naphthol skeletons, and naphthylene ether skeletons, and naphthol aralkyl skeletons and naphthalene skeletons are preferred. The aromatic skeletons containing a cardo skeleton, including preferred examples thereof, are as described for the component (A).

[0078] The epoxy equivalent of the 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 the resin per equivalent of epoxy group. This epoxy equivalent can be measured according to JIS K7236.

[0079] 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).

[0080] In the photosensitive resin composition set of the present invention, the content of the (B) component in the resin composition is, from the viewpoint of being able to further enjoy the effects of the present invention and from the viewpoint of further improving the mechanical strength and insulation reliability, preferably 15 mass% or more, more preferably 20 mass% or more, even more preferably 25 mass% or more, 26 mass% or more, 28 mass% or more, or 30 mass% or more, and the upper limit is preferably 60 mass% or less, more preferably 50 mass% or less, even more preferably 45 mass% or less, 44 mass% or less, 42 mass% or less, or 40 mass% or less.

[0081] From the viewpoint of enjoying 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 (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 (A)core and (B)core satisfy the relationship of 0.1≦(A)core / (B)core≦5. The lower limit of the ratio of (A)core / (B)core is more preferably 0.3 or more, still more preferably 0.5 or more, still more preferably 0.6 or more, 0.65 or more, or 0.7 or more, and the upper limit of the ratio is more preferably 3 or less, still more preferably 2 or less, still more preferably 1.5 or less, 1.4 or less, or 1.2 or less.

[0082] From the viewpoint of obtaining 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 of 0.1≦(A)clad / (B)clad≦5. The lower limit of the ratio of (A)clad / (B)clad 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, or 0.7 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.

[0083] <(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.

[0084] Component (C) does not include components (A) and (B) described above. For example, in relation to component (A), component (C) does not have to contain a carboxyl group, and in relation to component (B), component (C) does not have to contain an epoxy group.

[0085] 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.

[0086] 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 alcohols such as trimethylolpropane, pentaerythritol, and dipentaerythritol, or polyhydric acrylates of their ethylene oxide, propylene oxide, or ε-caprolactone adducts; phenols such as phenoxy acrylate and phenoxyethyl acrylate, or acrylates such as 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, polyvalent acrylates or polyvalent methacrylates are preferred. For example, trivalent acrylates or methacrylates include trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, trimethylolpropane EO-added tri(meth)acrylate, glycerin PO-added 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, dipentaerythritol tetra(meth)acrylate, Examples of the photosensitive (meth)acrylate compounds include hexa(meth)acrylate and (meth)acrylic acid ester of N,N,N',N'-tetrakis(β-hydroxyethyl)ethyldiamine, and examples of the acrylates or methacrylates having a valence of three or more include phosphoric acid 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.

[0087] Commercially available products can be used as component (C), such as "DPHA" and "TMPTA" manufactured by Nippon Kayaku Co., Ltd., and "EBECRYL160S", "EBECRYL895", "EBECRYL896", "EBECRYL3708", and "PETA" manufactured by Daicel Allnex Corporation.

[0088] 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. The lower limit of Mw of component (C) is not particularly limited, but may 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).

[0089] The viscosity of component (C) is usually 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.

[0090] In the photosensitive resin composition set of the present invention, the content of the component (C) in the resin composition is, from the viewpoint of better enjoying the effects of the present invention, preferably 15 mass% or more, more preferably 20 mass% or more, even more preferably 25 mass% or more, 26 mass% or more, 28 mass% or more, or 30 mass% or more, and the upper limit is preferably 60 mass% or less, more preferably 50 mass% or less, even more preferably 45 mass% or less, 44 mass% or less, 42 mass% or less, or 40 mass% or less.

[0091] From the viewpoint of enjoying the effects of the present invention, when the content of the (C) component in the core resin composition when the non-volatile components of the core resin composition are taken as 100% by mass is taken as (C)core, and the content of the (C) component in the clad resin composition when the non-volatile components of the clad resin composition are taken as 100% by mass is taken as (C)clad, it is preferable that (C)core and (C)clad satisfy the relationship of 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, 1.2 or less, or 1.1 or less. In particular, when the ratio of (C)clad / (C)core is in the range of 0.9 or more and 1.5 or less, it is preferable from the viewpoint of enjoying the effects of the present invention particularly. Therefore, in a preferred embodiment, (C)core and (C)clad satisfy the relationship: 0.9≦(C)clad / (C)core≦1.5.

[0092] From the viewpoint of enjoying 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 (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 (A)core and (C)core satisfy the relationship of 0.1≦(A)core / (C)core≦5. The lower limit of the ratio of (A)core / (C)core is more preferably 0.3 or more, still more preferably 0.5 or more, still more preferably 0.6 or more, 0.7 or more, or 0.8 or more, and the upper limit of the ratio is more preferably 3 or less, still more preferably 2 or less, still more preferably 1.5 or less, 1.4 or less, or 1.2 or less.

[0093] 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 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 (A)clad and (C)clad satisfy the relationship of 0.1≦(A)clad / (C)clad≦5. The lower limit of the ratio of (A)clad / (C)clad 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, 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.

[0094] <(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. The component (D) may be used alone or in combination of two or more. Note that component (D) does not include those corresponding to the above components (A), (B), and (C).

[0095] (D) The photopolymerization initiator may be any compound, and examples of such photopolymerization initiators include acylphosphine oxide-based photopolymerization initiators such as bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide and 2,4,6-trimethylbenzoyl-diphenyl-phosphine 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]-, and 1-(O-acetyloxime); 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-1-butanone, 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-[4-(4-morpholinyl)phenyl]-1-butanone, and 2-methyl-1-[4-(methyl α-aminoalkylphenone-based photopolymerization initiators such as ... 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, with an acylphosphine oxide-based photopolymerization initiator being more preferred.

[0096] 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.

[0097] In the photosensitive resin composition set of the present invention, the content of the (D) component in the resin composition is, from the viewpoint of better enjoying the effects of the present invention, preferably 0.1 mass% or more, more preferably 0.5 mass% or more, even more preferably 1 mass% or more, still more preferably 1.5 mass% or more, 2 mass% or more, 2.5 mass% or more, or 3 mass% or more, and the upper limit is preferably 20 mass% or less, more preferably 15 mass% or less, even more preferably 10 mass% or less, 8 mass% or less, 6 mass% or less, or 5 mass% or less.

[0098] In the photosensitive resin composition set of the present invention, the content of the component (D) in the resin composition, relative to 100 parts by mass of the total amount of the non-volatile components of the components (A) and (C) of 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, 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.

[0099] <(E) Compound Having a Group Selected from Monovalent Group E1, Monovalent Group E2, and Monovalent Group E3> In the photosensitive resin composition set of the present invention, at least the cladding resin composition contains, as component (E), a compound having, per molecule, one or more groups selected from the monovalent group E1 (i.e., a monovalent group represented by formula (E1)), the monovalent group E2 (i.e., a monovalent group represented by formula (E2)), and the monovalent group E3 (i.e., a monovalent group represented by formula (E3)).

[0100] [ka]

[0101] (In formula (E1), R S1 each independently represents a substituent, n1 represents an integer of 1 to 3; * indicates the binding site.)

[0102] [ka]

[0103] (In formula (E2), R 1 represents a hydrogen atom or a hydrocarbon group, R S2 each independently represents a substituent, n2 represents an integer of 0 to 5; * indicates the binding site.)

[0104] [ka]

[0105] (In formula (E3), X 1 represents a monovalent organic group.

[0106] As long as the relationship of the (E)core / (E)clad ratio is satisfied, the core resin composition may also contain the (E) component.

[0107] The component (E) may use either a single type alone, or a combination of two or more types.

[0108] In formula (E1), R S1 R each independently represents a substituent. S1The substituent represented by the formula (I) is as described above, and among them, from the viewpoint of further enjoying the effects of the present invention, an alkyl group is preferable, an alkyl group having 1 to 10 carbon atoms is more preferable, an alkyl group having 1 to 6 carbon atoms is even more preferable, and a methyl group or a t-butyl group is even more preferable.

[0109] In formula (E1), n1 represents an integer of 1 to 3. In order to obtain the effects of the present invention more effectively, n1 is preferably 1 or 2, and more preferably 1.

[0110] In formula (E1), R S1 The bonding position of is at least one of the ortho and meta positions with respect to the hydroxy group. From the viewpoint of obtaining the effects of the present invention more effectively, it is preferable to have R S1 is preferably bonded to the hydroxy group. S1 is bonded, R is placed at the para position relative to the t-butyl group shown in formula (E1). S1 is preferably bonded.

[0111] In formula (E2), R 1 R represents a hydrogen atom or a hydrocarbon group. 1 From the viewpoint of obtaining the effects of the present invention more effectively, the hydrocarbon group represented by the formula (I) is preferably a monovalent aliphatic hydrocarbon group. The monovalent aliphatic hydrocarbon group is as described above, and among them, an alkyl group, a cycloalkyl group, or an alkenyl group is preferable, an alkyl group is more preferable, and an alkyl group having 1 to 10 carbon atoms (preferably 1 to 6, 1 to 4, 1 or 2) is even more preferable.

[0112] In formula (E2), R S2 R each independently represents a substituent. S2 The substituent represented by the formula (I) is as described above, and among them, from the viewpoint of further enjoying the effects of the present invention, an alkyl group is preferable, and an alkyl group having 1 to 10 carbon atoms (preferably 1 to 6, 1 to 4, 1 or 2) is more preferable.

[0113] In formula (E2), n2 represents an integer of 0 to 5. In order to obtain the effects of the present invention more effectively, n2 is preferably an integer of 0 to 3, and more preferably 0 or 1.

[0114] In formula (E3), X 1 represents a monovalent organic group. The organic group is as described above. 1 is preferably a monovalent hydrocarbon group, more preferably a monovalent aliphatic hydrocarbon group, even more preferably an alkyl group, and even more preferably an alkyl group having 1 to 20 carbon atoms (preferably 1 to 18, 1 to 13, or 1 to 10).

[0115] The component (E) has one or more specific groups selected from the monovalent group E1, the monovalent group E2, and the monovalent group E3 in one molecule. The number of the specific groups that the component (E) has in one molecule, i.e., the valence, is preferably 2 or more from the viewpoint of being able to enjoy the effects of the present invention more effectively in combination with the components (A) to (D). When the component (E) has a valence of 2 or more, the specific groups may be the same or different from each other. The component (E) may be, for example, a compound having a valence of 2 or more and having two or more groups corresponding to the monovalent group E1, a compound having a valence of 2 or more and having two or more groups corresponding to the monovalent group E2, or a compound having a valence of 2 or more and having two or more groups corresponding to the monovalent group E3. In addition, the component (E) may be, for example, a compound of valence two or more having one or more groups corresponding to the monovalent group E1 and one or more groups corresponding to the monovalent group E2, a compound of valence two or more having one or more groups corresponding to the monovalent group E1 and one or more groups corresponding to the monovalent group E3, or a compound of valence two or more having one or more groups corresponding to the monovalent group E2 and one or more groups corresponding to the monovalent group E3.

[0116] In the component (E), the remaining structure (hereinafter also referred to as "residue") excluding the specific group selected from the monovalent group E1, the monovalent group E2, and the monovalent group E3 is not particularly limited as long as it is an organic group. For example, in the component (E) having a valence of n and having n specific groups (n is an integer of 1 or more), the residue is an n-valent organic group. The organic group is as described above, but from the viewpoint of being able to enjoy the effects of the present invention more effectively in combination with the components (A) to (D), it is preferably an aliphatic hydrocarbon group, a heteroatom-containing aliphatic group, or an aromatic hydrocarbon group. The aliphatic hydrocarbon group is as described above, but from the viewpoint of obtaining the effects of the present invention more effectively, a group in which n hydrogen atoms have been removed from an aliphatic compound selected from the group consisting of alkanes and alkenes is preferred. The number of carbon atoms in these alkanes and alkenes is as described above for the aliphatic hydrocarbon group, but is preferably 2 or more, more preferably 3 or more, and the upper limit is preferably 30 or less, more preferably 20 or less, 15 or less, or 10 or less. The heteroatom-containing aliphatic group is as described above, but from the viewpoint of enjoying the effects of the present invention, it is preferable that the heteroatom-containing aliphatic group contains a heteroatom selected from an oxygen atom and a nitrogen atom. Among them, a group obtained by removing n hydrogen atoms from an aliphatic compound containing a heteroatom selected from the group consisting of a heteroalkane containing a heteroatom selected from an oxygen atom and a nitrogen atom, and a heteroalkene containing a heteroatom selected from an oxygen atom and a nitrogen atom is preferable. These heteroalkanes and heteroalkenes preferably contain heteroatoms as -O-, -N<, -C(=O)-, or a combination thereof, and these heteroalkanes and heteroalkenes may also contain a cyclic structure (e.g., an aliphatic carbon ring; an aliphatic heterocycle containing a heteroatom selected from an oxygen atom and a nitrogen atom). The number of heteroatoms in these heteroalkanes and heteroalkenes is as described above for the heteroatom-containing aliphatic group, but is preferably 2 or more, more preferably 4 or more, 6 or more, or 8 or more, and the upper limit is preferably 20 or less, more preferably 15 or less, 14 or less, or 12 or less. The number of carbon atoms in these heteroalkanes and heteroalkene is as described above for the heteroatom-containing aliphatic group, but is preferably 4 or more, more preferably 6 or more, and the upper limit is preferably 30 or less, more preferably 25 or less, 24 or less, or 22 or less. The aromatic hydrocarbon group is as described above, but from the viewpoint of obtaining the effects of the present invention more effectively, a group in which n hydrogen atoms have been removed from an aromatic hydrocarbon compound containing an aromatic carbon ring having 6 to 14 carbon atoms (preferably 6 to 10) is preferred. The number of carbon atoms in such an aromatic hydrocarbon compound is as described above for the aromatic hydrocarbon group, but is preferably 40 or less, more preferably 30 or less, even more preferably 25 or less, 24 or less, 22 or less, or 20 or less.

[0117] The equivalent of the specific group selected from monovalent group E1, monovalent group E2, and monovalent group E3 in the component (E) is preferably 50 g / eq. to 1,000 g / eq., more preferably 80 g / eq. to 900 g / eq., and even more preferably 100 g / eq. to 800 g / eq., 100 g / eq. to 700 g / eq., or 100 g / eq. to 600 g / eq. The equivalent of the specific functional group represents the mass of the component (E) per equivalent of the specific functional group.

[0118] The molecular weight of the (E) component (weight average molecular weight Mw when it has a distribution) is preferably 3,000 or less, more preferably 2,000 or less, and even more preferably 1,500 or less, 1,400 or less, or 1,200 or less. The lower limit is not particularly limited, but may be, for example, 300 or more.

[0119] The component (E) may be a commercially available product. Examples of compounds having a monovalent group E1 include "AO-20" (valence 3, residue is a heteroatom-containing aliphatic group having 6 heteroatoms and 6 carbon atoms), "AO-30" (valence 3, residue is an aliphatic hydrocarbon group having 4 carbon atoms), "AO-40" (valence 2, residue is an aliphatic hydrocarbon group having 4 carbon atoms), "AO-50", "AO-50F", "AO-50T" (all have a valence 1, residue is a heteroatom-containing aliphatic group having 2 heteroatoms and 21 carbon atoms), "AO-60", "AO-60G" (all have a valence 4, residue is a heteroatom-containing aliphatic group having 8 heteroatoms and 17 carbon atoms), "AO-80" (valence 2, residue is a heteroatom-containing aliphatic group having 8 heteroatoms and 21 carbon atoms), and "AO-330" (valence 3, residue is an aromatic hydrocarbon group having 12 carbon atoms containing a benzene ring) manufactured by ADEKA Corporation, and "Irganox Examples of compounds having a monovalent group E2 include "LA-52" and "LA-57" manufactured by ADEKA Corporation (both have a valence of 4, and the residue is a heteroatom-containing aliphatic group having 8 heteroatoms and 8 carbon atoms). Examples of compounds having both a monovalent E1 and a monovalent group E2 include "Tinuvin 144" manufactured by BASF Corporation (valence of 3, and the residue is a heteroatom-containing aliphatic group having 4 heteroatoms and 8 carbon atoms). Examples of compounds having a monovalent group E3 include "JPE-10" and "JPE-13R" manufactured by Johoku Chemical Industry Co., Ltd.

[0120] In the photosensitive resin composition set of the present invention, when the content (% by mass) of the (E) component 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 the (E) component in the clad resin composition when the non-volatile components of the clad resin composition are taken as 100% by mass is defined as (E)clad, it is important that (E)core and (E)clad satisfy the relationship 0.6≦(E)clad-(E)core≦12. When (E)core and (E)clad satisfy the above relationship, the effect of the present invention can be achieved, that is, an optical waveguide can be produced in which the change in optical transmission loss is small even when exposed to a high-temperature environment. 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 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.

[0121] In the photosensitive resin composition set of the present invention, the content of the component (E) in the clad 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, 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 15% by mass or less, more preferably 13% by mass or less, 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. Thus, in one embodiment, the content of the component (E) in the clad resin composition, i.e., (E)clad, is 1 to 13% by mass when the non-volatile components of the clad resin composition are taken as 100% by mass.

[0122] As described above, the core resin composition may contain the (E) component as long as the difference between (E)core and (E)clad, i.e., the above relationship of (E)clad-(E)core, is satisfied. When the core resin composition contains the (E) component, the content of the (E) component in the core resin composition is not particularly limited, but is preferably 10% by mass or less, more preferably 5% by mass or less, further 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 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, 0.2% by mass or more, etc.

[0123] <(F) Curing accelerator> In the photosensitive resin composition set of the present invention, the resin composition may contain (F) a curing accelerator as an optional component. The component (F) functions as a curing catalyst that accelerates the curing of the component (B) and the like. The component (F) may be used alone or in combination of two or more types. Note that the component (F) does not include those corresponding to the above components (A) to (E).

[0124] Examples of the component (F) include imidazole-based curing accelerators, phosphorus-based curing accelerators, urea-based curing accelerators, guanidine-based curing accelerators, metal-based curing accelerators, amine-based curing accelerators, etc. Among these, imidazole-based curing accelerators are preferred.

[0125] Examples of the imidazole-based 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-undecylimidazolium 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 , 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, 2-phenylimidazoline, and other imidazole compounds and adducts of imidazole compounds and epoxy resins. Commercially available imidazole curing accelerators include, for example, "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 Chemical Industry Co., Ltd.; and "P200-H50" manufactured by Mitsubishi Chemical Corporation.

[0126] Examples of the phosphorus-based curing accelerator include aliphatic phosphonium salts such as tetrabutyl phosphonium bromide, tetrabutyl phosphonium chloride, tetrabutyl phosphonium acetate, tetrabutyl phosphonium decanoate, tetrabutyl phosphonium laurate, bis(tetrabutyl phosphonium)pyromellitate, tetrabutyl phosphonium hydrogenhexahydrophthalate, tetrabutyl phosphonium 2,6-bis[(2-hydroxy-5-methylphenyl)methyl]-4-methylphenolate, and di-tert-butyldimethylphosphonium tetraphenylborate; methyl triphenyl phosphonium bromide, ethyl triphenyl phosphonium bromide, propyl triphenyl phosphonium bromide, butyl triphenyl phosphonium bromide, benzyl triphenyl phosphonium chloride, tetraphenyl phosphonium bromide, p-tolyl triphenyl phosphonium tetra-p-tolylborate, tetraphenyl phosphonium bromide, and the like. 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 Examples of aromatic phosphines include 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.

[0127] 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 butylurea, 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].

[0128] Examples of the guanidine curing accelerator 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.

[0129] 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 organocobalt complexes such as cobalt(II) acetylacetonate and cobalt(III) acetylacetonate, organocopper complexes such as copper(II) acetylacetonate, organozinc complexes such as zinc(II) acetylacetonate, organoiron complexes such as iron(III) acetylacetonate, organonickel complexes such as nickel(II) acetylacetonate, and organomanganese complexes such as manganese(II) acetylacetonate. Examples of organometallic salts include zinc octylate, tin octylate, zinc naphthenate, cobalt naphthenate, tin stearate, and zinc stearate.

[0130] Examples of the amine-based 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-based curing accelerators may be used, such as "MY-25" manufactured by Ajinomoto Fine-Techno Co., Ltd.

[0131] In the photosensitive resin composition set of the present invention, the content of the (F) component in the resin composition is not particularly limited, and may be, for example, 0 mass% or more, 0.001 mass% or more, 0.01 mass% or more, 0.1 mass% or more, 0.3 mass% or more, etc. The upper limit of the content of the (F) component in the resin composition is preferably 5 mass% or less, more preferably 3 mass% or less, even more preferably 1 mass% or less, 0.8 mass% or less, or 0.6 mass% or less.

[0132] <(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. (G) Other additives include, for example, 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 pyrazonides, 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, carbon black, and naphthalene. Examples of additives include colorants such as black; 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 silane coupling agents, plasticizers, antistatic agents, antiaging agents, antibacterial agents, leveling agents, adhesion imparting agents, thixotropy imparting agents, release agents, surface treatment agents, dispersants, surface modifiers, and stabilizers.

[0133] <(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 non-volatile components (A) to (G) described above. By including the component (H), the viscosity of the resin composition can be adjusted. The component (H) may be used alone or in combination of two or more.

[0134] Examples of the (H) organic solvent 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 solvents such as petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, and solvent naphtha.

[0135] The content of the component (H) in the resin composition is preferably appropriately adjusted from the viewpoint of the coatability of the resin composition.

[0136] [Method of producing resin composition] In the photosensitive resin composition set of the present invention, the resin composition can be produced by mixing each component 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 the components (A) to (D) and, if necessary, the components (E) to (H), and the clad resin composition can be produced by mixing the components (A) to (E) and, if necessary, the components (F) to (H). When mixing, if necessary, kneading may be performed using a kneading device such as a three-roll mill, a ball mill, a bead mill, or a sand mill, or stirring may be performed using a stirring device such as a super mixer or a planetary mixer. There is no restriction on the order in which each component is mixed. In addition, cooling or heating may be performed during the process of mixing each component.

[0137] [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. The refractive index n 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 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. The refractive index n core can be measured by the method described later in <Test Example 1: Measurement of refractive index of cured resin composition>.

[0138] 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. The refractive index n 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 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. The refractive index n clad can be measured by the method described in <Test Example 1: Measurement of refractive index of cured resin composition> in the Examples described below.

[0139] 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 the refractive index n clad may have:

[0140]

number

[0141] In formula (2), n corerepresents 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. Refractive index n core and the 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, even more preferably 0.16 or less, or 0.15 or less.

[0142] According to the photosensitive resin composition set of the present invention, an optical waveguide having a small optical transmission loss can be manufactured. For example, when the optical transmission loss of the optical waveguide is measured according to the method described later in <Test Example 5: Measurement of Optical Transmission Loss>, the optical transmission loss (before HTS test; L1) is preferably less than 1.0 dB / cm, more preferably less than 0.5 dB / cm, and even more preferably less than 0.4 dB / cm.

[0143] According to the photosensitive resin composition set of the present invention, an optical waveguide with small change in optical transmission loss even when exposed to a high temperature environment can be manufactured. For example, when the optical transmission loss of an optical waveguide is measured according to the method described later in <Test Example 5: Measurement of Optical Transmission Loss>, the rate of change of the optical transmission loss value (L2) after the HTS test (150°C, 1000 hours) from the optical transmission loss value (L1) before the HTS test can be preferably less than 30%, more preferably less than 20%, and even more preferably less than 10%. In addition to the small optical transmission loss value (L1) before the HTS test, the optical waveguide manufactured using the photosensitive resin composition set of the present invention has a characteristic that the optical transmission loss value (L2) after the HTS test is small. The optical transmission loss value (L2) of the optical waveguide manufactured using the photosensitive resin composition set of the present invention after the HTS test (150°C, 1000 hours) can be preferably less than 1.0 dB / cm, more preferably less than 0.6 dB / cm, and even more preferably less than 0.5 dB / cm.

[0144] The photosensitive resin composition set of the present invention can provide excellent resolution (narrow-line waveguide formability) in producing an optical waveguide. For example, when attempting to form a line layer having a thickness of 5 μm and an L / S (line / space) of 5 μm / 5 μm and a line layer having a thickness of 50 μm and an L / S (line / space) of 50 μm / 50 μm according to the method described later in <Test Example 3: Evaluation of Resolution (Narrow-Line Waveguide Formability)>, preferably at least one of the line layers can be formed, and more preferably both of the line layers can be formed.

[0145] The photosensitive resin composition set of the present invention can 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 in <Test Example 4: Evaluation of the ratio of the shrinkage rates of the core layer and the clad layer> in the Examples described later can be calculated as follows: core and the shrinkage rate of the cladding layer c clad Compared to c core / c clad is preferably 0.80 or more, more preferably 0.90 or more, even more preferably 0.95 or more, and is preferably 1.20 or less, more preferably 1.10 or less, even more preferably 1.05 or less.

[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 for forming an optical waveguide capable of transmitting light having a wavelength of 1300 nm to 1320 nm. In particular, the core resin composition is preferably used for forming a single-mode optical waveguide, for example, for forming a single-mode optical waveguide for light having 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 for forming 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 for forming a single-mode optical waveguide, for example, for forming a single-mode optical waveguide for light having a wavelength of 1310 nm.

[0148] Thus, 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. 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] A resin sheet can be produced using each resin composition in the photosensitive resin composition set of the present invention. In particular, 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 manufacturing an optical waveguide. According to the photosensitive resin sheet set of the present invention, the same advantages as those of the above-mentioned photosensitive resin composition set can be obtained, and further, since it is possible to manufacture an optical waveguide by a lamination method, it is possible to more easily manufacture 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 a polyethylene terephthalate film, a polyethylene naphthalate film, a polypropylene film, a polyethylene film, a polyvinyl alcohol film, a triacetyl acetate film, and the like, with a polyethylene terephthalate film being particularly preferred.

[0154] Examples of commercially available supports include, but are not limited to, polyethylene terephthalate films such as "Alphan MA-410" and "E-200C" manufactured by Oji Paper Co., Ltd., polypropylene films manufactured by Shin-Etsu Film Co., Ltd., and PS series films such as "PS-25" manufactured by Teijin Co., Ltd. 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. By making the thickness 5 μm or more, it is possible to prevent the support from being torn when peeling the support before development, and by making the thickness 50 μm or less, it is possible to improve the resolution when exposing from above the support. In addition, a support with low fisheyes is preferable. Here, fisheyes are foreign matter, undissolved matter, oxidized deterioration products, etc. of the material that are taken into the film when the material is thermally melted and then kneaded, extruded, biaxially stretched, cast, etc. to produce a film.

[0155] In order to reduce scattering of light during exposure to actinic rays such as ultraviolet rays, the support is preferably one having excellent transparency. Specifically, the support is preferably one having 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 by a protective film, regardless of whether it is a core resin sheet or a clad resin sheet. By protecting the resin composition layer side of the resin sheet with a protective film (cover film), it is possible to prevent adhesion of dirt and the like to the surface of the resin composition layer and scratches. As the protective film, a film made of the same material as the support can be used. 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. By making the thickness 1 μm or more, the handleability of the protective film can be improved, and by making the thickness 40 μm or less, the cost tends to be improved. In addition, 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] The 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 on a support, and drying the organic solvent by heating or blowing hot air to form a resin composition layer. When producing a core resin sheet, the core resin composition may be used, and when producing a clad resin sheet, the clad resin composition may be used. Specifically, first, bubbles in the resin composition are removed by a vacuum degassing method or the like, and then the resin composition is applied onto a support, the solvent is removed by a hot air oven or a far-infrared oven, and the resin sheet can be produced by laminating a protective film on the obtained resin composition layer as necessary. Specific drying conditions vary depending on the curability of the resin composition and the amount of organic solvent in the resin varnish, but in a resin varnish containing 30% by mass to 60% by mass of organic solvent, drying can be performed at 80°C to 120°C for 3 minutes to 13 minutes. The amount of the remaining organic solvent in the resin composition layer is preferably 5% by mass or less, more preferably 2% by mass or less, based on the total amount of the resin composition layer in order to prevent the organic solvent from diffusing in a later step. Those skilled in the art can appropriately determine suitable drying conditions 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, even more preferably 10 μm or more, and is preferably 100 μm or less, more preferably 50 μm or less, 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, 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 portions, may be applied in one portion, or may be applied by a combination of different methods. Among them, the die coating method is preferable because of its excellent uniformity of application. In addition, in order to avoid contamination by foreign matter, it is preferable to carry out the application process in an environment where foreign matter is unlikely to be generated, such as a clean room.

[0162] [Optical waveguide] The above-mentioned photosensitive resin composition set and photosensitive resin sheet set can be used to manufacture an optical waveguide. The present invention also provides such an optical waveguide. Hereinafter, an embodiment of the optical waveguide will be described with reference to the drawings.

[0163] FIG. 1 is a perspective view showing a schematic diagram of 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 the core resin composition of the photosensitive resin composition set of the present invention, and preferably includes only the cured product of the core resin composition of the photosensitive resin composition set of the present invention. The clad layer 200 includes a cured product of the clad resin composition of the photosensitive resin composition set of the present invention, and preferably includes only the cured product of the clad resin composition of the photosensitive resin composition set of the present invention.

[0164] 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 circumferential 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 through the core layer 100 from one end (the end on the incident side) 100A of the core layer 100 to the other end (the end on the exit side) 100B.

[0165] The wavelength of light that can be transmitted by the optical waveguide 10 can be selected from various wavelengths. For example, the preferred wavelength range 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 them, the preferred wavelength range of the light transmitted through the optical transmission line 10 is 1300 nm to 1320 nm.

[0166] The optical waveguide 10 may be a single-mode optical waveguide or a multimode 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 above-mentioned preferred wavelength range. For example, the optical waveguide 10 is preferably a single-mode optical waveguide for light of 1310 nm.

[0167] It is desirable to set the width L of the core layer 100 appropriately within a range in which light can be transmitted. 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.

[0168] It is desirable to set the interval S of the core layers 100 appropriately within a range in which light transmission is possible. A specific range of the interval 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 interval S of the core layers 100 corresponds to the interval (space) of the core layers as viewed in the thickness direction.

[0169] It is desirable to appropriately set the thickness T of the core layer 100 within a range in which light transmission is possible. 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.

[0170] 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.

[0171] 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 conductor 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.

[0172] The substrate 300 may be a hard substrate such as a glass substrate, a metal substrate, a ceramic substrate, a wafer, or a circuit substrate. The wafer may be a semiconductor wafer such as a silicon wafer, a gallium arsenide (GaAs) wafer, an indium phosphide (InP) wafer, a gallium phosphide (GaP) wafer, a gallium nitride (GaN) wafer, a gallium telluride (GaTe) wafer, a zinc selenium (ZnSe) wafer, or a silicon carbide (SiC) wafer, or a pseudo wafer. The pseudo wafer may be a plate-shaped member having a mold resin and electronic components embedded in the mold resin. The circuit substrate may be a glass epoxy substrate, a metal substrate, a polyester substrate, a polyimide substrate, a BT resin substrate, or a thermosetting polyphenylene ether substrate. The circuit substrate may be a substrate having a patterned conductor layer (circuit) formed on one or both sides of the substrate. 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 .

[0173] Furthermore, the optical waveguide 10 may include, as an optional element, a protective layer (not shown) for protecting the core layer 100 and the cladding layer 200. The protective layer may be provided, for example, so as to cover the surface of the cladding layer 200 opposite to the substrate 300.

[0174] The optical waveguide 10 can be produced using the photosensitive resin composition set of the present invention. For example, the optical waveguide 10 is A step (I) of forming a first composition layer containing a cladding resin composition; A step (II) of curing the first composition layer; (III) forming a second composition layer containing a core resin composition on the first composition layer; A step (IV) of subjecting the second composition layer to an exposure treatment; A step (V) of subjecting the second composition layer to a development treatment; A step (VI) of curing the second composition layer; (VII) forming a third composition layer containing a cladding resin composition on the second composition layer; A step (VIII) of curing the third composition layer; In addition, if necessary, the method may further include a step (IX) of forming a conductor layer on the cladding layer after the step (VII).

[0175] Fig. 2 is a schematic cross-sectional view for explaining step (I) of the method for producing an optical waveguide according to one embodiment of the present invention. As shown in Fig. 2, the method for producing an optical waveguide according to one embodiment of the present invention includes step (I) of forming a first composition layer 210 containing a cladding resin composition. In this embodiment, an example of forming the first composition layer 210 on a substrate 300 will be shown and explained.

[0176] There is no particular limitation on the method for forming the first composition layer 210. For example, the first composition layer 210 may be formed by applying a clad resin composition onto the substrate 300. From the viewpoint of smooth application, a varnish-like clad resin composition containing a solvent may be prepared, and the varnish-like clad resin composition may be applied.

[0177] Examples of coating methods include gravure coating, microgravure coating, reverse coating, kiss reverse coating, die coating, slot die, lip coating, comma coating, blade coating, roll coating, knife coating, curtain coating, chamber gravure coating, slot orifice, spin coating, slit coating, spray coating, dip coating, hot melt coating, bar coating, applicator, air knife coating, curtain flow coating, offset printing, brush coating, and screen printing.

[0178] The cladding resin composition may be applied in one application or in multiple applications. Also, different application methods may be combined. In order to avoid contamination by foreign matter, it is preferable to apply the composition in an environment where foreign matter is unlikely to be generated, such as a clean room.

[0179] After application of the cladding resin composition, the first composition layer 210 may be dried as necessary. Drying can be performed using a drying device such as a hot air oven or a far infrared oven. It is preferable to set the drying conditions appropriately according to the composition of the cladding resin composition. To give a specific example, 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. In addition, 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 less, more preferably 20 minutes or less, and even more preferably 5 minutes or less.

[0180] The first composition layer 210 may be formed, for example, by using a clad resin sheet. As a specific example, the resin composition layer of the clad resin sheet is laminated onto the substrate 300, thereby forming the first composition layer 210 on the substrate 300. The lamination is usually performed by pressing the resin composition layer of the clad resin sheet onto the substrate 300 while heating it. This lamination is preferably performed under reduced pressure by a vacuum lamination method. Furthermore, prior to lamination, a preheat treatment may be performed to heat the resin sheet and the substrate, if necessary.

[0181] The lamination conditions are, for example, a pressure bonding temperature (lamination temperature) of 70°C to 140°C and a pressure bonding pressure of 1kgf / 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. The lamination is preferably carried out under reduced pressure with an air pressure of 20 mmHg (26.7 hPa) or less. The lamination may be carried out in a batch manner or continuously using a roll.

[0182] 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., and a vacuum laminator manufactured by Hitachi AIC Co., Ltd.

[0183] When the first composition layer 210 is formed using a clad resin sheet having a support, the support is usually peeled off at an appropriate time before the step (III).

[0184] 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.

[0185] The method for producing an optical waveguide according to one embodiment of the present invention includes, after step (I), step (II) of curing the first composition layer 210. This step (II) may, for example, involve heat treating the first composition layer 210. 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.

[0186] The first composition layer 210 may be cured by exposure to light. In one example, the specific exposure dose range is preferably 10 mJ / cm. 2 More preferably, 50 mJ / cm 2 More preferably, 200 mJ / cm 2 or more, preferably 10,000 mJ / cm 2Less than or equal to 8,000 mJ / cm 2 Less than 4,000 mJ / cm, more preferably 4,000 mJ / cm 2 Below 3,000mJ / cm 2 Below, 2,000mJ / cm 2 or less than 1,000 mJ / cm 2 The first composition layer 210 may also be cured by a combination of an exposure treatment and a heat treatment.

[0187] 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.

[0188] Fig. 3 is a schematic cross-sectional view for explaining step (II) of the method for producing an optical waveguide according to one embodiment of the present invention. 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.

[0189] 4 is a schematic cross-sectional view for explaining step (III) of the 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 includes, after step (III), step (III) of forming a second composition layer 110 containing a core resin composition on a lower clad layer 220 as a cured first composition layer, as shown in FIG.

[0190] There is no particular limitation 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 the varnish-like core resin composition may be applied. The application of the core resin composition may be performed in the same manner as the application of the clad resin composition. After application of the core resin composition, the second composition layer 110 may be dried as necessary. The drying of the second composition layer 110 may be performed using the same method and conditions as those for drying the first composition layer 210.

[0191] The second composition layer 110 may be formed, for example, by 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 lamination of the core resin sheet can be performed in the same manner as the lamination of the clad resin sheet. In addition, the support of the core resin sheet is peeled off at an appropriate time before the step (V).

[0192] The second composition layer 110 formed on the lower clad layer 220 in the step (III) contains a core resin composition, and preferably contains only the core resin composition.

[0193] 5 is a schematic cross-sectional view for explaining step (IV) of the method for producing an optical waveguide according to one embodiment of the present invention. As shown in FIG. 5, the method for producing an optical waveguide according to one embodiment of the present invention includes, after step (III), step (IV) of subjecting the second composition layer 110 to an exposure treatment.

[0194] 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 to a specific portion of the second composition layer 110. Thus, when the exposure treatment is performed, the second composition layer 110 is provided with an exposed portion 111 that is irradiated with light and a non-exposed portion 112 that is not irradiated with light. Since the core resin composition usually functions as a negative photosensitive resin composition, a latent image corresponding to the core layer is formed by the exposed portion 111.

[0195] From the viewpoint of performing selective exposure, the exposure treatment in the step (IV) is usually performed using a mask 400. Specifically, in this exposure treatment, the second composition layer 110 is irradiated with light P through the mask 400 having a light-transmitting portion 410 and a light-shielding portion 420. The light P passes through the light-transmitting portion 410 and enters the exposed portion 111, but cannot pass through the light-shielding portion 420 and therefore cannot enter the non-exposed portion 112. Thus, the exposed portion 111 and the non-exposed portion 112 corresponding to the light-transmitting portion 410 and the light-shielding portion 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 as shown in FIG. 5 (contact exposure method), or exposure may be performed using parallel light without being in close contact (non-contact exposure method).

[0196] In general, 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 seen from the thickness direction. The light-transmitting portion 410 formed in the planar shape corresponding to the core layer may be referred to as a "mask pattern" hereinafter.

[0197] The light P used in the exposure treatment in step (IV) may be active light 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 the exposure dose in step (IV) may be the same as that of the first composition layer 210 in step (II).

[0198] 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.

[0199] Since the core resin composition functions as a negative photosensitive resin composition, the solubility in a developer is reduced in the exposed area 111. On the other hand, the solubility in a developer is high in the non-exposed area 112. Utilizing this difference in solubility between the exposed area 111 and the non-exposed area 112, the subsequent development process in step (VI) is carried out.

[0200] The method for producing an optical waveguide according to one embodiment of the present invention 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 more and 110° C. or less. The heating time may be, for example, 30 seconds or more and 60 minutes or less.

[0201] FIG. 6 is a schematic cross-sectional view for explaining step (V) of the 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 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. Since the core resin composition functions as a negative photosensitive resin composition, as shown in FIG. 6, the exposed portion 111 is not removed by the development treatment, while the non-exposed portion 112 (see FIG. 5) is removed. The exposed portion 111 of the second composition layer 110 remaining after development may have the same planar shape as the mask pattern of the light-transmitting portion 410 (see FIG. 5) of the mask 400 used in step (IV).

[0202] The developing method is usually a wet developing method in which the second composition layer 110 is brought into contact with a developer. An alkaline aqueous solution is usually used as the developer.

[0203] Examples of the alkaline aqueous solution as a developer include an aqueous solution of an alkali metal compound. Examples of the alkali metal compound include an alkali metal hydroxide such as lithium hydroxide, sodium hydroxide, or potassium hydroxide; an alkali metal carbonate or bicarbonate such as sodium carbonate or sodium bicarbonate; an alkali metal phosphate such as sodium phosphate or potassium phosphate; an alkali metal pyrophosphate such as sodium pyrophosphate or potassium pyrophosphate. Examples of the alkaline aqueous solution include an aqueous solution of an organic base that does not contain metal ions, such as tetramethylammonium hydroxide. The alkaline aqueous solution may be used alone or in combination of two or more. Among them, an aqueous solution of an organic base that does not contain metal ions is preferred from the viewpoint of obtaining the effects of the present invention remarkably.

[0204] The developer may contain additives such as a surfactant and an antifoaming agent, if necessary, to improve the developing action.

[0205] 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 preferably 50° C. or lower, more preferably 40° C. or lower.

[0206] Examples of the developing method include a paddle method, a spray method, an immersion method, a brushing method, a slapping method, and an ultrasonic method. Among them, the spray method is suitable for improving the resolution. When the spray method is adopted, the spray pressure is preferably 0.05 MPa to 0.3 MPa.

[0207] After development using the developer, the second composition layer 110 may be further rinsed. Rinsing is preferably performed with a solvent different from the developer. For example, rinsing may be performed with the same type of solvent contained in the core resin composition or water. The rinsing time is preferably 5 seconds to 1 minute.

[0208] In addition, after development using a developer, a desmear treatment may be performed to remove non-exposed areas that cannot be completely removed by development. The desmear treatment may be performed according to various methods used in the manufacture of printed wiring boards and known to those skilled in the art.

[0209] The method for producing an optical waveguide according to one embodiment of the present invention includes, after step (V), step (VI) of curing the second composition layer 110. This step (VI) usually 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).

[0210] 7 is a schematic cross-sectional view for explaining step (VI) of the method for producing an optical waveguide according to one embodiment of the present invention. By curing second composition layer 110 in step (VI), as shown in FIG. 7, core layer 100 is obtained as a cured second composition layer on lower clad layer 220.

[0211] Fig. 8 is a schematic cross-sectional view for explaining step (VII) of the method for producing an optical waveguide according to one embodiment of the present invention. As shown in Fig. 9, the method for producing an optical waveguide according to one embodiment of the present invention includes, after step (VI), step (VIII) 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 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.

[0212] There is no particular limitation on the method for forming the third composition layer 230. For example, the third composition layer 230 may be formed by applying a cladding photosensitive resin composition onto the core layer 100 (and, if necessary, onto the lower cladding layer 220). The application of the cladding resin composition for forming the third composition layer 230 may be performed in the same manner as the application of the cladding resin composition for forming 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 for drying the first composition layer 210.

[0213] The third composition layer 230 may be formed, for example, using a clad resin sheet. As a specific example, the resin composition layer of the clad resin sheet is laminated to the core layer 100 (and the lower clad layer 220, if necessary), thereby forming the third composition layer 230 on the core layer 100. The lamination of the clad resin sheet for forming the third composition layer 230 may be performed in the same manner as the lamination of the clad resin sheet for forming 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.

[0214] The third composition layer 230 formed on the core layer 100 in the step (VIII) contains a cladding photosensitive resin composition, and preferably contains only a cladding photosensitive resin composition.

[0215] The method for producing an optical waveguide according to one embodiment of the present invention includes, after the step (VII), a step (VIII) of curing the third composition layer 230. The curing of the third resin composition layer 230 in this step (VIII) can usually be carried out in the same manner as the curing of the first composition layer 210.

[0216] 9 is a schematic cross-sectional view for explaining step (VIII) of the method for producing an optical waveguide according to one embodiment of the present invention. 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. 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 upper cladding layer 240 and the lower cladding layer 220 form the cladding layer 200. Thus, an optical waveguide 10 including the cladding layer 200 including the lower cladding layer 220 and the upper cladding layer 240, and the core layer 100 provided in the cladding layer 200 can be obtained.

[0217] FIG. 10 is a schematic cross-sectional view for explaining step (IX) of the 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.

[0218] The procedure and conditions of 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.

[0219] Examples of the swelling liquid used in the roughening treatment include an alkaline solution and a surfactant solution, and an alkaline solution is preferred. As the alkaline solution, a sodium hydroxide solution and a potassium hydroxide solution are more preferred. Examples of commercially available swelling liquids include "Swelling Dip Securigans P" and "Swelling Dip Securigans SBU" manufactured by Atotech Japan. The swelling treatment using the swelling liquid is not particularly limited, but can be performed by immersing the insulating layer in a swelling liquid at 30°C to 90°C for 1 to 20 minutes. From the viewpoint of suppressing the swelling of the resin of the insulating layer to an appropriate level, it is preferred to immerse the insulating layer in a swelling liquid at 40°C to 80°C for 5 to 15 minutes.

[0220] An example of an oxidizing agent used in the roughening treatment is an alkaline permanganate solution in which potassium permanganate or sodium permanganate is dissolved in an aqueous solution of sodium hydroxide. The roughening treatment using an oxidizing agent such as an alkaline permanganate solution is preferably performed by immersing the insulating layer in an oxidizing agent solution heated to 60°C to 100°C for 10 minutes to 30 minutes. The concentration of permanganate in the alkaline permanganate solution is preferably 5% by mass to 10% by mass. Examples of commercially available oxidizing agents include alkaline permanganate solutions such as "Concentrate Compact CP" and "Dosing Solution Securigans P" manufactured by Atotech Japan.

[0221] The neutralizing solution used in the roughening treatment is preferably an acidic aqueous solution, and a commercially available product is, for example, "Reduction Solution Securigant P" manufactured by Atotech Japan. Treatment with a neutralizing solution can be performed 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 viewpoint of workability, etc., a method in which the object that has been roughened with an oxidizing agent is immersed in a neutralizing solution at 40°C to 70°C for 5 to 20 minutes is preferred.

[0222] The arithmetic mean roughness Ra of the upper clad layer surface after the roughening treatment is preferably 500 nm or less, more preferably less than 400 nm, even more preferably 200 nm or less, more preferably less than 200 nm. There is no particular lower limit, and it can be, for example, 1 nm or more, 2 nm or more, etc.

[0223] After completion of the roughening treatment, the conductor layer 500 is formed on the upper clad layer 240 that has been subjected to the roughening treatment. Specifically, the surface of the core layer 100 is 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 production, it is preferable to form the conductor layer by the semi-additive method. An example of forming the conductor layer by the semi-additive method will be described below.

[0224] 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 to expose a part 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 to form a conductor layer 500 having a desired wiring pattern.

[0225] The method for producing the optical waveguide 10 may further include any optional steps in combination with the steps described above.

[0226] 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.

[0227] The above-mentioned steps may be repeated in the method for producing the optical waveguide 10. For example, steps (I) to (IX) may be repeated to produce 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.

[0228] [Opto-electrical hybrid board and its manufacturing method] An optical / electrical hybrid board according to an embodiment of the present invention includes the optical waveguide described above. Typically, the optical / 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; active components such as semiconductor chips; and the like. The optical waveguide and the wiring of the electric circuit board may be connected via a photoelectric conversion element. The photoelectric conversion element may include a combination of a light-emitting element (e.g., a surface-emitting light-emitting diode) capable of converting electricity into light, and a light-receiving element (e.g., a photodiode) capable of converting light into electricity. Furthermore, the optical / electrical hybrid board may include an optical element such as a mirror for adjusting the optical path.

[0229] A preferred example of an opto-electrical hybrid board 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 board 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.

[0230] In chips manufactured by silicon photonics, generally, light with wavelengths of 1310 nm and 1550 nm is often used, with 1310 nm being the most common (Sho Yoshida, Daisuke Suganuma, Takaaki Ishigure, "Fabrication of Single-Mode Polymer Waveguides and Low Loss Using the Mosquito Method," 28th Spring Lecture Meeting of the Japan Institute of Electronics Packaging, 2014). Therefore, it is preferable that the optical waveguide is capable of transmitting light with wavelengths of 1310 nm and 1550 nm or close thereto, and for example, it is preferable that the optical waveguide is capable of transmitting light with wavelengths of 1300 nm to 1320 nm. The optical waveguide according to the above-mentioned embodiment is capable of transmitting light with these wavelengths.

[0231] Generally, the single mode can achieve faster transmission than the multimode. Therefore, from the viewpoint of high-speed transmission, the single mode optical waveguide is preferable as an optical waveguide applied to an optical-electrical hybrid circuit. In the single mode optical waveguide, the width of the core layer is preferably small. For example, it is preferable to form a core layer having a width of 10 μm or less, or 5 μm or less. In addition, an optical waveguide having such a small core layer is 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 waveguide according to the above-mentioned embodiment, it is possible to reduce the width of the core layer as described above.

[0232] On the other hand, when connecting multiple opto-electric hybrid boards, the boards may be connected via optical fibers. For example, multiple opto-electric hybrid boards may be installed in a rack, and the opto-electric hybrid boards may be connected to each other via optical fibers. Multimode optical fibers are the mainstream for connecting boards in this way. Therefore, from the viewpoint of enabling connection with the optical fibers, a multimode optical waveguide may be adopted as the optical waveguide provided in the opto-electric hybrid board.

[0233] From the viewpoint of increasing versatility, it is desirable that the optical waveguide is applicable to both single mode and multimode. Furthermore, it is desirable to reduce the minimum width of the core layer of the optical waveguide to increase the degree of freedom of the line width of the core layer. According to the optical waveguide of the above-mentioned embodiment, a fine core can be formed by using the core resin composition of the present invention for the core, so that the minimum width of the core layer can be reduced. Furthermore, according to the optical waveguide of the above-mentioned embodiment, both single mode and multimode optical waveguides can be obtained. Therefore, the optical waveguide of the above-mentioned embodiment can be applied in a wide range. And, since it is applicable in such a wide range and can suppress the transmission loss of light, the optical waveguide of the above-mentioned embodiment is suitable for application to an opto-electrical hybrid board.

[0234] Since the opto-electrical hybrid board includes the above-mentioned optical waveguide, the manufacturing method of the opto-electrical hybrid board includes the same method as the manufacturing method of the optical waveguide. EXAMPLES

[0235] The present invention will be described in detail below with reference to examples, but the present invention 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).

[0236] <Synthesis Example 1: Synthesis of Naphthol Aralkyl Skeleton-Containing Acid-Modified Epoxy Acrylate Resin> 325 parts of an epoxy resin having a naphthol aralkyl skeleton with an epoxy equivalent of 330 g / eq. ("ESN-475V", manufactured by Nippon Steel Chemical & Material Co., Ltd.) was placed in a flask equipped with a gas inlet tube, a stirrer, a cooling tube, and a thermometer, 340 parts of propylene glycol monomethyl ether was added, and the mixture was dissolved by heating, and 0.46 parts of hydroquinone and 1 part of triphenylphosphine were added. This mixture was heated to 95 to 105°C, and 72 parts of acrylic acid were gradually added dropwise and reacted for 16 hours. This reaction product was cooled to 80 to 90°C, and 130 parts of tetrahydrophthalic anhydride was added, reacted for 8 hours, and cooled. The solvent was removed to obtain an acid-modified epoxy acrylate resin having an acid value of 90 mgKOH / g in solid matter and 70% by mass of non-volatile components. The weight average molecular weight (Mw) of the obtained acid-modified epoxy acrylate resin was 1,000.

[0237] <Production Example 1: Production of varnish-like resin composition and resin sheet> (1) Preparation of a varnish-like resin composition The mixture was mixed with 15 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 of about 330 g / eq.), 5 parts of a naphthalene-type tetrafunctional epoxy resin ("HP-4710" manufactured by DIC Corporation, epoxy equivalent of about 170 g / eq.), 12.5 parts of a photocurable resin ("DPHA" manufactured by Nippon Kayaku Co., Ltd., dipentaerythritol hexaacrylate), 1.5 parts of a photopolymerization initiator ("Omnirad 379EG" manufactured by IGM), and 1.5 parts of a hindered phenol-based antioxidant ("Iragnox" manufactured by BASF). A varnish-like resin composition was prepared by mixing 0.1 parts of a curing accelerator ("1BP2Z", 1-benzyl-2-phenylimidazole, manufactured by Shikoku Kasei Corporation) and 0.2 parts of a curing accelerator ("1BP2Z", manufactured by Shikoku Kasei Corporation) using a high-speed rotating mixer.

[0238] (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 with a die coater so that the thickness of the resin composition layer after drying was 5 μm, 6.5 μm, 10 μm, 20 μm, or 50 μm, and the support was 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 having a three-layer structure of support / resin composition layer / protective film.

[0239] <Production Examples 2 to 14: Production of varnish-like resin compositions and resin sheets> A varnish-like resin composition was prepared and a resin sheet was produced in the same manner as in Production Example 1, except that the components were mixed according to the composition shown in Table 1 below. In Table 1, the meanings of the abbreviations are as follows.

[0240] (A) Carboxyl group-containing resin "Synthesis Example 1": Naphthol aralkyl skeleton-containing acid-modified epoxy acrylate resin (acid value 90 mgKOH / g, Mw: 1000) synthesized in Synthesis Example 1, non-volatile content 70% by mass

[0241] (B) Epoxy resin "HP-4710": DIC Corporation, naphthalene-type tetrafunctional epoxy resin, epoxy equivalent approx. 170g / eq. "ESN-475V": Manufactured by Nippon Steel Chemical & Material Co., Ltd., naphthol aralkyl-based epoxy resin, epoxy equivalent of approximately 330g / eq.

[0242] (C) Photocurable resin "DPHA": Dipentaerythritol hexaacrylate, manufactured by Nippon Kayaku Co., Ltd.

[0243] (D) Photopolymerization initiator "Omnirad 379EG": 2-dimethylamino-2-(4-methyl-benzyl)-1-(4-morpholin-4-yl-phenyl)-butan-1-one, manufactured by IGM

[0244] (E) Compounds with specific groups "Irganox 1010": BASF Corporation, a compound represented by the following formula (E-1), pentaerythritol tetrakis{3-[3,5-di(tert-butyl)-4-hydroxyphenyl]propionate} "AO-80": ADEKA Corporation, product name "ADEKA STAB (registered trademark) AO-80", a compound represented by the following formula (E-2), 3,9-Bis{2-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]-1,1-dimethylethyl}-2,4,8,10-tetraoxaspiro[5.5]undecane "AO-20": ADEKA Corporation, product name "ADEKA STAB (registered trademark) AO-20", a compound represented by the following formula (E-3), 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione "AO-30": ADEKA Corporation, product name "ADEKA STAB (registered trademark) AO-30", a compound represented by the following formula (E-4), 4,4',4"-(1-methylpropanyl-3-ylidene)tris(6-tert-butyl-m-cresol) "AO-330": ADEKA Corporation, product name "ADEKA STAB (registered trademark) AO-330", a compound represented by the following formula (E-5), 1,3,5-tris(3,5-di-tert-butyl-4-hydroxyphenylmethyl)-2,4,6-trimethylbenzene "JPE-10": manufactured by Johoku Chemical Industry Co., Ltd., a compound represented by formula (E-6), bis(isodecyl)pentaerythritol diphosphite "LA-57": ADEKA Corporation, product name "ADEKA STAB (registered trademark) LA-57", a compound represented by the following formula (E-7), 1,2,3,4-butanetetracarboxylic acid tetrakis(2,2,6,6-tetramethyl-4-piperidinyl) "Tinuvin 144": BASF's product name "Tinuvin (registered trademark) 144", a compound represented by the following formula (E-8), 2-butyl-2-[3,5-di(tert-butyl)-4-hydroxybenzyl]malonate bis(1,2,2,6,6-pentamethyl-4-piperidinyl)

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[0251] [ka]

[0252] [ka]

[0253] (E') Compounds Having No Specific Groups "Tinuvin 123": BASF Corporation, product name "Tinuvin (registered trademark) 123", a compound represented by the following formula (E'-1), bis[1-(octyloxy)-2,2,6,6-tetramethyl-4-piperidinyl] sebacate

[0254] [ka]

[0255] (F) Curing accelerator "1B2PZ": 1-benzyl-2-phenylimidazole, manufactured by Shikoku Chemical Industry Co., Ltd.

[0256] (G) Other Ingredients "TD-2090": DIC Corporation, phenol novolac type phenolic hardener

[0257] <Test Example 1: Measurement of refractive index of cured resin composition> The refractive index of the cured product of the resin composition used in producing the resin sheet was measured by the following method.

[0258] 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 for 30 seconds with a 1.0 mass % aqueous solution of tetramethylammonium hydroxide at 23° C. as a developer at a spray pressure of 0.1 MPa. After spray development, the resin composition layer was sprayed with 3 J / cm 2 The sample was then subjected to UV irradiation for 100 s, followed by heat treatment at 190°C for 90 minutes in a nitrogen atmosphere to obtain a sample formed of a cured product of the resin composition. The refractive index n (1310 nm) of the obtained sample was measured at room temperature and normal pressure using a 1310 nm laser beam with a 2010M prism coupler (manufactured by Metricon).

[0259] <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 and the silicon wafer were in contact with each other, and laminated using a vacuum laminator ("VP160" manufactured by Nikko Materials Co., Ltd.). The lamination conditions were a vacuum drawing 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. Thereafter, the support was peeled off to obtain a laminate A having a silicon wafer and a resin composition layer.

[0260] 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 an exposure energy such that the number of gloss remaining steps of a 41-step tablet was 8 to 10. The exposure was performed 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 line corresponds to the width of the core layer, and the space corresponds to the distance between the core layers. After the exposure, the resin composition layer 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 the spray development, 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, and the vertical and horizontal lengths of the rectangular core were measured to calculate the area α. Then, the wafer was placed in a clean oven, heated from room temperature to 190°C, and after reaching 190°C, a heat treatment was performed for 69 minutes to harden the resin composition layer. After the resin was hardened, the same cross section was observed, 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).

[0261] The amounts of raw materials used in the preparation of the resin composition of each Production Example and the measurement results of the Test Examples are shown in Table 1 below.

[0262] [Table 1]

[0263] <Example 1: Formation of optical waveguide> The sheets manufactured in Production Example 1 and Production Example 2 were prepared, and the resolution and optical transmission loss were evaluated by the following methods.

[0264] <Test Example 3: Evaluation of Resolution (Formability of Thin-Wire Waveguide)> A copper layer of a glass epoxy substrate (copper-clad laminate) having a copper layer of 18 μm in thickness 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 having a resin composition layer of 10 μm in thickness manufactured in Manufacturing Example 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 with each other, and laminated using a vacuum laminator ("VP160" manufactured by Nikko Materials Co., Ltd.). The lamination conditions were a vacuum drawing 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. Thereafter, the support was peeled off, and ultraviolet light exposure was performed using a projection exposure device ("UFX-2240" manufactured by Ushio Inc.) with exposure energy such that the number of gloss remaining steps of a 41-step step tablet was 8 steps. The exposure was performed without using a quartz glass mask. After exposure, 2 J / cm 2 After that, the laminate was 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 the curing of the resin composition layer, and an intermediate laminate B1 including a copper-clad laminate and a lower clad layer was obtained.

[0265] Next, the protective film was peeled off from the 5 μm-thick resin sheet produced in Production Example 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 the intermediate laminate B1 were in contact with each other, and laminated 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 drawing 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 a laminate B2 having a copper-clad laminate, a lower clad layer, and a resin sheet in this order. Thereafter, the support was peeled off to expose the resin composition layer.

[0266] 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 of a 41-step tablet was 8. The exposure was performed using a quartz glass mask having a mask pattern that draws 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 a developer at a spray pressure of 0.2 MPa for 1 minute. After spray development, the substrate was exposed to 2 J / cm 2 By irradiating the copper-clad laminate with ultraviolet light for 1 hour and then performing a heat treatment at 190°C for 1 hour in a nitrogen atmosphere, sample B3 was obtained which had, in that order, a copper-clad laminate, a lower clad layer, and a 5 μm-thick line layer (a layer formed of a cured product of the resin composition).

[0267] In addition, the thickness of the resin sheet produced in Production Example 1 was changed to 50 μm, and a quartz glass mask having a mask pattern that draws straight lines with L / S (line / space) = 50 μm / 50 μm was used. Except for this, the same operations as above were performed to obtain sample B4, which has, in that 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).

[0268] The obtained samples B3 and B4 were observed with a scanning electron microscope (SEM) (magnification: 2000 times). The resolution was evaluated according to the following evaluation criteria. The line width refers to the width of the line layer.

[0269] Evaluation criteria "Good": A line having a line width of 5 μm at a thickness of 5 μm was formed, and a line having a line width of 50 μm at a thickness of 50 μm was formed. "Δ": Either a line having a line width of 5 μm at a thickness of 5 μm or a line having a line width of 50 μm at a thickness of 50 μm was not formed. "X": Neither a line having a line width of 5 μm at a thickness of 5 μm nor a line having a line width of 50 μm at a thickness of 50 μm was formed.

[0270] <Test Example 4: Calculation of the ratio of shrinkage rates of the core layer and the clad layer> In each of the examples and comparative examples, 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 Compared to c core / c clad was calculated.

[0271] <Test Example 5: Measurement of optical transmission loss> (1-1. Formation of the lower cladding layer) A copper layer of a glass epoxy substrate (copper-clad laminate) having a copper layer of 18 μm in thickness was roughened with a surface treatment agent (CZ8100, manufactured by MEC Co., Ltd.) containing an organic acid to prepare a substrate. A protective film was peeled off from a resin sheet having a resin composition layer of 10 μm in thickness manufactured in Manufacturing Example 2. A resin sheet was placed on the copper-clad laminate so that the resin composition layer of the resin sheet and the copper-clad laminate of the substrate were in contact with each other, 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 pressure of 0.3 MPa, and a pressure time of 30 seconds. Thereafter, the support was peeled off, and ultraviolet light exposure was performed using a projection exposure device ("UFX-2240" manufactured by Ushio Inc.) with exposure energy such that the number of gloss remaining steps of a 41-step step tablet was 8 steps. The exposure was performed without using a quartz glass mask. After exposure, 2 J / cm 2 After that, the laminate was 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 the curing of the resin composition layer, and an intermediate laminate C1 including a copper-clad laminate and a lower clad layer was obtained.

[0272] (1-2. Formation of the core layer) The protective film was peeled off from the resin sheet having a resin composition layer with a thickness of 5 μm produced in Production Example 1. A resin sheet was placed on the surface of the lower clad layer of the intermediate laminate C1 so that the resin composition layer of the resin sheet and the lower clad layer of the intermediate laminate C1 were in contact with each other, and laminated using a vacuum laminator ("VP160" manufactured by Nikko Materials Co., Ltd.). The lamination conditions were a vacuum drawing 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. Thereafter, the support was peeled off, and ultraviolet light exposure was performed using a projection exposure device ("UFX-2240" manufactured by Ushio Inc.) with an exposure energy such that the number of gloss remaining steps of the 41-step step tablet was 8 steps. The exposure was performed using a quartz glass mask having a mask pattern capable of drawing a plurality of straight lines with a length of 5 cm at L / S (line / space) = 5 μm / 100 μm. In the L / S of this quartz glass mask, the line corresponds to the width of the core layer, and the space corresponds to the interval between the core layers. After exposure, the film was left to stand at room temperature for 30 minutes, the support was peeled off, and 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 spray pressure was 2 J / cm 2 After that, the laminate was 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 harden the resin composition layer. A core layer was formed by hardening the resin composition layer, and an intermediate laminate C2 having a copper-clad laminate, a lower clad layer, and a core layer in this order was obtained.

[0273] (1-3. Formation of upper cladding layer) The protective film was peeled off from the resin sheet having a resin composition layer of 20 μm thickness produced in Production Example 2. The resin sheet was placed on the core layer of the intermediate laminate C2 so that the resin composition layer of the resin sheet and the core layer of the intermediate laminate C2 were in contact with each other, 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 bonding temperature of 60°C, a pressure bonding pressure of 0.3 MPa, and a pressure time of 30 seconds. Thereafter, the support was peeled off, and ultraviolet light exposure was performed using a projection exposure device (Ushio Inc.'s "UFX-2240") with exposure energy such that the number of gloss remaining steps of the 41-step step tablet was 8 steps. The exposure was performed without using a quartz glass mask. After exposure, 2 J / cm 2 After that, the sample was 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 the curing of the resin composition layer, and a sample laminate C3 having a copper-clad laminate, a lower clad layer, a core layer, and an upper clad layer in this order was obtained.

[0274] In this sample laminate C3, the combination of the lower cladding layer and the upper cladding layer constitutes the cladding layer. Thus, an optical waveguide including the cladding layer and the core layer in the cladding layer was obtained. In addition, in this sample laminate C3, the core layer had a linear pattern with a length of 5 cm corresponding to the mask pattern of the quartz glass mask, and the width (line width) and interval (space) of the core layer included in such pattern were consistent with the width (line width) and interval (space) of the mask pattern.

[0275] (2. Preparation of test board) From the sample laminate C3 produced by the above operation, the portion where the core layer was formed, i.e., the core layer on which the 5 cm linear pattern was drawn and the clad layer around it, were cut out to obtain a test substrate C4 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, 80umt)

[0276] (3-1. Measurement of optical transmission loss of the calibration optical system) As described later, the transmission loss of the optical system for measuring the transmission loss of the test board C4 was measured by removing the test board C4 and the light collecting module from the optical system. That is, a light source (1310 nm light source, THORLABS's "LPSC-1310-FC") and a light receiver (Keysight's optical power meter "N7742") were connected via an optical fiber (input fiber) on a vibration isolation table covered with a blackout curtain to obtain an optical system for calibration. The light source was made to emit light, and the intensity of the light that entered the light receiver was measured by the light receiver to measure the loss of this optical system for calibration.

[0277] (3-2. Measurement of optical transmission loss) A test substrate C4 was placed on a vibration isolation table covered with a blackout curtain. A light collecting module (numerical aperture 0.18) was connected to one end (input end) of the optical waveguide of the test substrate C4, and a light source (1310 nm light source, THORLABS's "LPSC-1310-FC") was connected to the light collecting module via an optical fiber (input fiber). Another light collecting module (numerical aperture 0.18) was connected to the other end (output end) of the optical waveguide of the test substrate C4, and a light receiver (Keysight's optical power meter "N7742") was connected to the light collecting module via an optical fiber (output fiber). Through the above operations, an optical system was obtained in which light emitted from the light source passes through the optical fiber (input fiber), the light collecting module, the optical waveguide, the light collecting module, and the optical fiber (output fiber) in this order, and then enters the light receiver. Hereinafter, this optical system may be referred to as a "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.

[0278] The loss of the optical waveguide included in the test substrate was determined by subtracting the loss of the calibration optical system from the loss of the sample optical system.

[0279] (3-3. Measurement of optical transmission loss (dB / cm) of optical waveguide before high temperature storage test (HTS test)) After the measurement of the loss of the 5 cm-long optical waveguide was completed, the optical waveguide was cut to 4 cm and the same measurement was performed. After that, the optical waveguide was cut to 3 cm and the measurement was repeated, and the measured values ​​were calculated for the 5 cm-long optical waveguide, the 4 cm-long optical waveguide, and the 3 cm-long optical waveguide. The measurement results were 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 approximation line of these three points was calculated by the least squares method, and the slope of the approximation line was obtained 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 evaluation criteria.

[0280] Evaluation criteria "◎": Optical transmission loss value is less than 0.40dB / cm "Good": Optical transmission loss is between 0.40 dB / cm and 0.50 dB / cm "△": Optical transmission loss value is 0.50 dB / cm or more and less than 1.00 dB / cm "X": Optical transmission loss value is 1.00 dB / cm or more

[0281] (4. Measurement of optical transmission loss (dB / cm) of optical waveguide after HTS test) Apart from the test substrate C4 used above, a test substrate C5 was prepared according to the same procedure. This test substrate C5 was left in an oven heated to 150°C for 1000 hours, and the above operations 3-1. to 3-3. were carried out to calculate the transmission loss value after the HTS test. Furthermore, the rate of change (%) of the calculated optical transmission loss value after the HTS test from the optical transmission loss value before the test was calculated, and evaluated according to the following evaluation criteria.

[0282] Evaluation criteria "◎": Change rate less than 10% "Good": Change rate is 10% or more but less than 20% "△": Change rate 20% or more but less than 30% "X": Change rate 30% or more

[0283] <Test Example 6: Checking the mode> The photoreceiver was removed from the test board C4 and an infrared camera (InGaAs camera with 100x objective lens) was set instead. The light source was turned on and the light emitted from the end of the optical fiber (output fiber) was photographed by the infrared camera. When only one circular light edge was observed, it was judged to be single mode. When multiple edges were observed, it was judged to be multimode.

[0284] <Examples 2 to 12 and Comparative Examples 1 to 4: Formation of Optical Waveguides> As shown in Table 2, optical waveguides were formed in the same manner as in Example 1, except that the combination of the resin composition for the core layer and the resin composition for the cladding layer was changed, and evaluated by each test.

[0285] The combinations of the core resin compositions and cladding resin compositions used in each of the Examples and Comparative Examples, and the evaluation results, are shown in the following Table 2. In the following Table 2, the meanings of the abbreviations are as follows. NA: numerical aperture of the optical waveguide (the numerical aperture NA is a value expressed by the following formula (1))

[0286]

number

[0287] "S" in the Mode column: Single mode "M" in the Mode column: Multimode

[0288] [Table 2]

[0289] In each of the examples, it has been confirmed that even when components (F) to (G) are not contained, the results are similar to those of the above examples, although to different degrees. [Explanation of symbols]

[0290] 10 Optical waveguide 100 Core Layer 110 Second composition layer 111 Exposure section 112 Non-exposed 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 Mask 410 Translucent part 420 Shading part 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, (B) an epoxy resin, (C) a photocurable resin, and (D) Photopolymerization initiator Including, At least the cladding resin composition further comprises (E) A compound having, in one molecule, one or more groups selected from a monovalent group represented by the following formula (E1), a monovalent group represented by the following formula (E2), and a monovalent group represented by the following formula (E3), When the content (mass%) of the (E) component in the core resin composition is defined as (E)core when the non-volatile components of the core resin composition are taken as 100 mass%, and the content (mass%) of the (E) component in the clad resin composition is defined as (E)clad when the non-volatile components of the clad resin composition are taken as 100 mass%, (E)core and (E)clad are 0.6≦(E)clad−(E)core≦12 A photosensitive resin composition set that satisfies the above relationship. 【Chemistry 1】 (In formula (E1), R Ｓ１ each independently represents a substituent, n1 represents an integer of 1 to 3; * indicates the binding site.) 【Chemistry 2】 (In formula (E2), R １ represents a hydrogen atom or a hydrocarbon group, R Ｓ２ each independently represents a substituent, n2 represents an integer of 0 to 5; * indicates the binding site.) 【Chemistry 3】 (In formula (E3), X １ represents a monovalent organic group.

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

3. The photosensitive resin composition set according to claim 1, wherein (E) clad is 1 to 13 mass%.

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

5. When the non-volatile components of the core resin composition are taken as 100 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. In this case, (A)core and (B)core are 0.1≦(A) core / (B) core≦5 The photosensitive resin composition set according to claim 1 , which satisfies the relationship:

6. 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 defined as 100 mass%, (A)clad and (B)clad are: 0.1≦(A) clad / (B) clad≦5 The photosensitive resin composition set according to claim 1 , which satisfies the relationship:

7. When the non-volatile components of the core resin composition are taken as 100 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. In this case, (A)core and (C)core are 0.1≦(A)core / (C)core≦5 The photosensitive resin composition set according to claim 1 , which satisfies the relationship:

8. 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 defined as 100 mass%, (A)clad and (C)clad are 0.1≦(A)clad / (C)clad≦5 The photosensitive resin composition set according to claim 1 , which satisfies the relationship:

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

10. 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.

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

12. A photosensitive resin sheet set including a core resin sheet and a clad resin sheet, The core resin sheet is provided with a resin composition layer containing the core resin composition in the photosensitive resin composition set according to any one of claims 1 to 11, A photosensitive resin sheet set, comprising a clad resin sheet having a resin composition layer containing the clad resin composition in the photosensitive resin composition set according to any one of claims 1 to 11.

13. An optical waveguide having a core layer and a clad layer, The core layer is (A) a carboxyl group-containing resin, (B) an epoxy resin, (C) a photocurable resin, and (D) Photopolymerization initiator and (E) a cured product of a core resin composition which may contain a compound having, in one molecule, one or more groups selected from a monovalent group represented by the following formula (E1), a monovalent group represented by the following formula (E2), and a monovalent group represented by the following formula (E3), The cladding layer is (A) a carboxyl group-containing resin, (B) an epoxy resin, (C) photocurable resin, (D) a photopolymerization initiator, and (E) A compound having, in one molecule, one or more groups selected from a monovalent group represented by the following formula (E1), a monovalent group represented by the following formula (E2), and a monovalent group represented by the following formula (E3): The present invention relates to a cured product of a cladding resin composition comprising the above-mentioned compound, When the content (mass%) of the (E) component in the core resin composition is defined as (E)core when the non-volatile components of the core resin composition are taken as 100 mass%, and the content (mass%) of the (E) component in the clad resin composition is defined as (E)clad when the non-volatile components of the clad resin composition are taken as 100 mass%, (E)core and (E)clad are 0.6≦(E)clad−(E)core≦12 An optical waveguide that satisfies the relationship: 【Chemistry 4】 (In formula (E1), R Ｓ１ each independently represents a substituent, n1 represents an integer of 1 to 3; * indicates the binding site.) 【Chemistry 5】 (In formula (E2), R １ represents a hydrogen atom or a hydrocarbon group, R Ｓ２ each independently represents a substituent, n2 represents an integer of 0 to 5; * indicates the binding site.) 【Chemistry 6】 (In formula (E3), X １ represents a monovalent organic group.

14. An optical / electrical hybrid board comprising the optical waveguide according to claim 13.

15. 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 subjecting the second composition layer to an exposure treatment; 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, (B) an epoxy resin, (C) a photocurable resin, and (D) Photopolymerization initiator Including, At least the cladding resin composition further comprises (E) A compound having, in one molecule, one or more groups selected from a monovalent group represented by the following formula (E1), a monovalent group represented by the following formula (E2), and a monovalent group represented by the following formula (E3): Including, When the content (mass%) of the (E) component in the core resin composition is defined as (E)core when the non-volatile components of the core resin composition are taken as 100 mass%, and the content (mass%) of the (E) component in the clad resin composition is defined as (E)clad when the non-volatile components of the clad resin composition are taken as 100 mass%, (E)core and (E)clad are 0.6≦(E)clad−(E)core≦12 A method for manufacturing an optical waveguide that satisfies the above relationship. 【Chemistry 7】 (In formula (E1), R Ｓ１ each independently represents a substituent, n1 represents an integer of 1 to 3; * indicates the binding site.) 【Chemistry 8】 (In formula (E2), R １ represents a hydrogen atom or a hydrocarbon group, R Ｓ２ each independently represents a substituent, n2 represents an integer of 0 to 5; * indicates the binding site.) 【Chemistry 9】 (In formula (E3), X １ represents a monovalent organic group.

16. 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 subjecting the second composition layer to an exposure treatment; 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, (B) an epoxy resin, (C) a photocurable resin, and (D) Photopolymerization initiator Including, At least the cladding resin composition further comprises (E) A compound having, in one molecule, one or more groups selected from a monovalent group represented by the following formula (E1), a monovalent group represented by the following formula (E2), and a monovalent group represented by the following formula (E3): Including, When the content (mass%) of the (E) component in the core resin composition is defined as (E)core when the non-volatile components of the core resin composition are taken as 100 mass%, and the content (mass%) of the (E) component in the clad resin composition is defined as (E)clad when the non-volatile components of the clad resin composition are taken as 100 mass%, (E)core and (E)clad are 0.6≦(E)clad−(E)core≦12 A method for manufacturing an optical / electrical hybrid board that satisfies the above relationship. 【Chemistry 10】 (In formula (E1), R Ｓ１ each independently represents a substituent, n1 represents an integer of 1 to 3; * indicates the binding site.) 【Chemistry 11】 (In formula (E2), R １ represents a hydrogen atom or a hydrocarbon group, R Ｓ２ each independently represents a substituent, n2 represents an integer of 0 to 5; * indicates the binding site.) 【Chemistry 12】 (In formula (E3), X １ represents a monovalent organic group.

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