Method of manufacturing optical waveguide

Abstract

Provided is a method for producing an optical waveguide having excellent dimensional stability using a thermosetting resin. A method for producing an optical waveguide (10) includes, in order: step (i), forming a metal-based wiring pattern (310) on a metal layer (302) of a base material (first base material) (300) having a metal layer; step (ii), forming a first resin composition layer (210) from a resin composition for coating, and curing the first resin composition layer to form a first coating layer (211); step (iii), removing a base material portion (301) of the first base material (300); step (iv), removing the metal layer (302) and the wiring pattern (310), and forming a recess portion corresponding to the wiring pattern (310); step (v), forming a second resin composition layer (110) from a resin composition for a core including a thermosetting resin, and curing the second resin composition layer to form a core base layer (111); step (vi), removing a portion of the core base layer to form a core layer (100); and step (vii), forming a third resin composition layer (220) from a resin composition for coating, and curing the third resin composition layer to form a second coating layer (221).

Description

Technical Field

[0001] This invention relates to a method for manufacturing optical waveguides. Background Technology

[0002] In recent years, research on optical signal transmission has been actively underway, focusing on high-capacity information transmission. With the progress of this research, it is believed that traditional electronic circuits will gradually be replaced by optical circuits. Therefore, optoelectronic hybrid circuits (CPOs), which combine optical and electrical circuits, are attracting considerable attention.

[0003] To achieve high-speed transmission, single-mode optical waveguides are desired as optical waveguides used to form optical circuits. Single-mode optical waveguides require dimensional stability (stability of pattern shape) (Patent Documents 1 and 2).

[0004] Existing technical documents Patent documents Patent Document 1: Japanese Patent Application Publication No. 2018-059955 Patent Document 2: Japanese Patent Application Publication No. 2018-045031. Summary of the Invention

[0005] The problem that the invention aims to solve Optical waveguides are manufactured by arranging multiple cores at predetermined intervals within a cladding to serve as light transmission paths. In the manufacturing methods of optical waveguides, from the viewpoint of efficiently forming waveguides with fine-linewidth cores at predetermined intervals, waveguides are typically manufactured using a cured product of a photosensitive resin composition containing a photocurable resin. However, if the photocurable resin is incorporated in a manner that allows for the formation of fine patterns, the stability of mechanical strength may sometimes deteriorate, potentially leading to increased transmission loss in the optical waveguide. Therefore, the inventors have attempted to form fine patterns in the optical waveguide using a thermosetting resin with excellent mechanical strength.

[0006] In detail, in order to use thermosetting resin to set micro-linewidth cores at specified intervals within a coating, a technique was investigated to form trenches in the coating by laser processing and to form cores within these trenches. However, when forming trenches in the coating by laser processing, the inventors confirmed the following problems: 1) Sometimes the cross-sectional shape of the trench is not rectangular, making it difficult to obtain a trench with the desired shape; 2) It is difficult to keep the depth of the laser-processed trench constant, and the trench depth sometimes becomes uneven when viewed in the extension direction of the trench; 3) Sometimes the bottom of the trench is rough, etc. Since the resulting core has a shape corresponding to the trench, the inventors have learned that it is difficult to form a core with the desired cross-sectional shape or the desired thickness in the extension direction using the above-described laser-processed trench forming technique. In addition, the inventors have learned that the result of using the above-described laser-processed trench forming technique is a core with a rough boundary surface with the coating. Thus, according to the inventors' research, when attempting to use thermosetting resins to form optical waveguides with fine patterns, it was determined that it was difficult to form a uniform pattern shape and that the dimensional stability was poor.

[0007] The present invention is proposed in view of the above and provides a method for manufacturing an optical waveguide with excellent dimensional stability using a thermosetting resin.

[0008] Methods for solving problems The inventors conducted in-depth research to solve the above-mentioned problems. As a result, the inventors discovered that the above-mentioned problems can be solved by the following method for manufacturing an optical waveguide, thereby completing the present invention. The method for manufacturing an optical waveguide sequentially includes: step (i), forming a metal-based wiring pattern on the metal layer of a substrate (first substrate) with a metal layer; step (ii), forming a first resin composition layer from an encapsulating resin composition in contact with the metal layer and the wiring pattern, and curing the first resin composition layer to form a first encapsulating layer; step (iii), removing a substrate portion of the first substrate; step (iv), removing the metal layer and the wiring pattern to form a recess corresponding to the wiring pattern; step (v), forming a second resin composition layer from a core resin composition comprising a thermosetting resin in contact with the recess, and curing the second resin composition layer to form a core substrate layer; step (vi), removing a portion of the core substrate layer to form a core layer; and step (vii), forming a third resin composition layer from an encapsulating resin composition in contact with the core layer and the first encapsulating layer, and curing the third resin composition layer to form a second encapsulating layer.

[0009] That is, the present invention includes the following contents.

[0010] <1> A method for manufacturing an optical waveguide, comprising the following steps: In step (i), a metal-based wiring pattern is formed on the metal layer of a substrate (first substrate) with a metal layer. Step (ii) involves forming a first resin composition layer from an encapsulating resin composition in a manner that contacts the metal layer and the wiring pattern, and curing the first resin composition layer to form a first encapsulating layer. Step (iii): Remove the substrate portion of the first substrate; Step (iv): Remove the metal layer and the wiring pattern to form a recess corresponding to the wiring pattern; Step (v) involves forming a second resin composition layer from a core resin composition comprising a thermosetting resin in a manner that contacts the recess, and curing the second resin composition layer to form a core base layer. Step (vi) involves removing a portion of the core substrate layer to form a core layer; and Step (vii) involves forming a third resin composition layer from the coating resin composition in contact with the core layer and the first coating layer, and then curing the third resin composition layer to form the second coating layer.

[0011] <2> <1> The manufacturing method described herein, wherein step (ii) includes step (ii-1): on the side of the first resin composition layer opposite to the substrate (first substrate) with the metal layer, a support (second substrate) is bonded to the first resin composition layer.

[0012] <3> <2> The manufacturing method further includes, after step (vii), step (viii): removing the support (second substrate).

[0013] The manufacturing method described in <4>, <2>, or <3>, wherein the support (second substrate) is a glass substrate, a single-crystal silicon substrate, or a silicon substrate with an inorganic film. The silicon substrate having the inorganic film has an inorganic film comprising a silicon oxide film on the surface bonded to the first resin composition layer.

[0014] The manufacturing method according to any one of <5> <1> to <4>, wherein the metal layer portion of the substrate with the metal layer (first substrate) comprises copper.

[0015] The manufacturing method according to any one of <6> <1> to <5>, wherein step (iv) includes step (iv-1): forming a recess by removing the metal layer and the wiring pattern by using a wet treatment with an etching solution.

[0016] The manufacturing method according to any one of <7>, <1> to <6>, wherein the substrate portion of the substrate with the metal layer (first substrate) is a glass substrate, a single-crystal silicon substrate, or a silicon substrate having an inorganic film. The silicon substrate having an inorganic film has an inorganic film comprising a silicon oxide film between the metal layer and the silicon substrate.

[0017] The manufacturing method according to any one of <8> <1> to <7>, wherein step (iii) includes step (iii-1): peeling off the substrate portion of the first substrate.

[0018] The manufacturing method according to any one of <9> <1> to <7>, wherein step (iii) includes step (iii-2): grinding the substrate portion of the first substrate.

[0019] The manufacturing method according to any one of <10> <1> to <9>, wherein step (vi) includes step (vi-1): forming a core layer by grinding a portion of the core substrate layer by chemical mechanical polishing (CMP).

[0020] The manufacturing method according to any one of <11> <1> to <10>, wherein the coating resin composition comprises a thermosetting resin.

[0021] The manufacturing method according to any one of <12> <1> to <11>, wherein, after step (i) and before step (ii), it further includes step (ii'): planarizing the surface of the wiring pattern by chemical mechanical polishing (CMP).

[0022] The manufacturing method according to any one of <1> to <12>, wherein the width of the core layer is 10 μm or less.

[0023] The manufacturing method according to any one of <14> <1> to <13>, wherein the manufactured optical waveguide is a single-mode optical waveguide.

[0024] The manufacturing method according to any one of <1> to <14>, wherein the refractive index of the cured core resin composition is set to n at a wavelength of 1310 nm. core Furthermore, the refractive index of the cured resin composition for coating is set as n. clad Under the condition that the following relationship is satisfied: n core -n clad ≤0.1.

[0025] The manufacturing method according to any one of <16> <1> to <15>, wherein the core resin composition comprises one or more resins selected from epoxy resin, (meth)acrylic resin, phenolic resin and silicone resin.

[0026] The manufacturing method according to any one of <17> <1> to <16>, wherein the coating resin composition comprises one or more resins selected from epoxy resin, (meth)acrylic resin, phenolic resin and silicone resin.

[0027] <18> An optoelectronic hybrid substrate having an optical waveguide manufactured by any one of <1> to <17>.

[0028] <19> A semiconductor device comprising the optoelectronic hybrid substrate described in <18>.

[0029] Invention Effects According to the present invention, a method for manufacturing optical waveguides with excellent dimensional stability can be provided by using thermosetting resins. Attached Figure Description

[0030] [ Figure 1 ] Figure 1 This is a schematic perspective view of an optical waveguide manufactured by the manufacturing method of the present invention.

[0031] [ Figure 2 ] Figure 2 This is a schematic cross-sectional view illustrating step (i) of the method for manufacturing the optical waveguide of the present invention.

[0032] [ Figure 3 ] Figure 3 This is a schematic cross-sectional view of step (i-1) involved in one embodiment of the method for manufacturing an optical waveguide according to the present invention.

[0033] [ Figure 4 ] Figure 4 This is a schematic cross-sectional view of step (i-2) involved in one embodiment of the method for manufacturing an optical waveguide according to the present invention.

[0034] [ Figure 5 ] Figure 5 This is a schematic cross-sectional view illustrating a portion of step (ii) in the method for manufacturing the optical waveguide of the present invention.

[0035] [ Figure 6 ] Figure 6 This is a schematic cross-sectional view illustrating a portion of step (ii) in the method for manufacturing the optical waveguide of the present invention.

[0036] [ Figure 7 ] Figure 7 This is a schematic cross-sectional view illustrating step (iii) of the method for manufacturing the optical waveguide of the present invention.

[0037] [ Figure 8 ] Figure 8 This is a schematic cross-sectional view illustrating step (iv) of the manufacturing method of the optical waveguide of the present invention.

[0038] [ Figure 9 ] Figure 9 This is a schematic cross-sectional view illustrating a portion of step (v) in the method for manufacturing the optical waveguide of the present invention.

[0039] [ Figure 10 ] Figure 10 This is a schematic cross-sectional view illustrating a portion of step (v) in the method for manufacturing the optical waveguide of the present invention.

[0040] [ Figure 11 ] Figure 11 This is a schematic cross-sectional view illustrating the process (vi) involved in the manufacturing method of the optical waveguide of the present invention.

[0041] [ Figure 12 ] Figure 12 This is a schematic cross-sectional view illustrating a part of step (vii) in the method for manufacturing the optical waveguide of the present invention.

[0042] [ Figure 13 ] Figure 13 This is a schematic cross-sectional view illustrating a part of step (vii) in the method for manufacturing the optical waveguide of the present invention. Detailed Implementation

[0043] The present invention will now be described in detail with reference to embodiments and examples. However, the present invention is not limited to the embodiments and examples described below, and may be implemented by any modifications without departing from the scope of the claims and their equivalents.

[0044] [Resin Composition] Before providing a detailed description of the method for manufacturing the optical waveguide of the present invention, the resin compositions used in steps (ii), (v), and (vii) of the method for manufacturing the optical waveguide of the present invention will be described.

[0045] In the manufacturing method of the optical waveguide of the present invention, the resin composition includes a core resin composition and a coating resin composition. The core resin composition is referred to as the resin composition for forming the core layer of the optical waveguide. The coating resin composition is referred to as the resin composition for forming the coating layer of the optical waveguide. In the manufacturing method of the present invention, an optical waveguide having a core layer comprising a cured core resin composition and a coating layer comprising a cured coating resin composition can be obtained.

[0046] <Core Resin Composition> In the method for manufacturing the optical waveguide of the present invention, the core resin composition comprises a thermosetting resin.

[0047] The thermosetting resin included in the core resin composition can be a resin that can cure upon heating. Examples of thermosetting resins include: epoxy resins, resins having free radical polymerizable groups, phenolic resins, reactive ester resins, carbodiimide resins, amine resins, acid anhydride resins, benzo[a]azine resins, cyanate ester resins, thiol resins, and silicone resins. A single thermosetting resin can be used alone, or two or more can be used in combination.

[0048] Examples of epoxy resins include: bixylenol type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol AF type epoxy resin, dicyclopentadiene type epoxy resin, triphenol type epoxy resin, naphthol phenolic varnish type epoxy resin, phenol phenolic varnish type epoxy resin, tert-butyl-catechol type epoxy resin, naphthalene type epoxy resin, naphthol type epoxy resin, anthracene type epoxy resin, glycidylamine type epoxy resin, and glycidyl... Epoxy resins include ester-type epoxy resins, cresol-phenolic varnish-type epoxy resins, biphenyl-type epoxy resins, linear aliphatic epoxy resins, butadiene-structured epoxy resins, alicyclic epoxy resins, heterocyclic epoxy resins, spirocyclic epoxy resins, cyclohexane-type epoxy resins, cyclohexane-diethanol-type epoxy resins, naphthyl ether-type epoxy resins, trimethylolpropionic acid epoxy resins, tetraphenylethane-type epoxy resins, glycidyl ether-type aliphatic epoxy resins, and glycidyl ether-type aromatic epoxy resins, etc. Epoxy resins can be used alone or in combination of two or more types.

[0049] Among thermosetting resins, epoxy resins are preferably epoxy resins having two or more epoxy groups per molecule. From the viewpoint of significantly obtaining the desired effects of the present invention, the amount of epoxy resin having two or more epoxy groups per molecule is preferably 50% by mass or more, more preferably 60% by mass or more, further preferably 70% by mass or more, and typically 100% by mass or less, relative to 100% by mass of epoxy resin.

[0050] Epoxy resins preferably have an aromatic structure. When using two or more epoxy resins, it is preferred that one or more epoxy resins have an aromatic structure. An aromatic structure refers to a chemical structure that is generally defined as aromatic, and also includes polycyclic aromatics and aromatic heterocycles.

[0051] The epoxy resin includes an epoxy resin that is liquid at 25°C (hereinafter sometimes referred to as "liquid epoxy resin") and an epoxy resin that is solid at 25°C (hereinafter sometimes referred to as "solid epoxy resin"). For the resin composition, the epoxy resin may consist only of liquid epoxy resin, or only of solid epoxy resin, or may consist of a combination of liquid and solid epoxy resins.

[0052] As a liquid epoxy resin, a liquid epoxy resin having two or more epoxy groups in one molecule is preferred.

[0053] Examples of liquid epoxy resins include: glycyrrhizin-type epoxy resins, bisphenol A-type epoxy resins, bisphenol F-type epoxy resins, bisphenol AF-type epoxy resins, naphthalene-type epoxy resins, glycidyl ether-type aliphatic epoxy resins, glycidyl ether-type aromatic epoxy resins, glycidyl ester-type epoxy resins, glycidyl amine-type epoxy resins, phenolic varnish-type epoxy resins, alicyclic epoxy resins with an ester skeleton, cyclohexanediol-type epoxy resins, dicyclopentadiene-type epoxy resins, and epoxy resins with a butadiene structure.

[0054] Specific examples of liquid epoxy resins include: DIC's "HP-4032", "HP-4032-D", and "HP-4032-SS" (naphthalene-type epoxy resin); Mitsubishi Chemical's "828US", "828EL", "825", and "EPIKOTE828EL" (bisphenol A type epoxy resin); Mitsubishi Chemical's "807" and "1750" (bisphenol F type epoxy resin); Mitsubishi Chemical's "152" (phenolic varnish type epoxy resin); Mitsubishi Chemical's "630", "630LSD", and "604" (glycidylamine type epoxy resin); ADEKA's "ED-523T" (glycyrrhizic acid type epoxy resin); and ADEKA's "EP-3950L" and "EP-3980S". (Glycidylamine type epoxy resin); ADEKA's "EP-4088S" (dicyclopentadiene type epoxy resin); Nippon Steel Chemical Materials Co., Ltd.'s "ZX1059" (a mixture of bisphenol A and bisphenol F type epoxy resins); Nagase ChemteX's "EX-252" and "EX-721" (glycidyl ester type epoxy resins); DAICL's "EHPE3150CE"; ENEOS's "THI-DE"; Resonac's "SHOFREE CDMDG"; SYMRISE's "LDO" (alicyclic epoxy resin); DAICL's "CELLOXIDE 2021P", "CELLOXIDE 2081P", "CELLOXIDE 2000", and "CELLOXIDE 8000" (Alicyclic epoxy resins with an ester backbone); "PB-3600" manufactured by DAICL; "JP-100" and "JP-200" manufactured by Nippon Soda (epoxy resins with a butadiene structure); "ZX1658" and "ZX1658GS" (liquid 1,4-glycidylcyclohexane type epoxy resin) manufactured by JITAC Chemical Materials; "YX8000" and "YX8034" (hydrogenated bisphenol A type epoxy resin) manufactured by Mitsubishi Chemical Corporation, etc. These can be used individually or in combination of two or more.

[0055] As a solid epoxy resin, a solid epoxy resin having three or more epoxy groups in one molecule is preferred.

[0056] Examples of solid epoxy resins include: xylenol-type epoxy resin, naphthalene-type epoxy resin, naphthalene-type tetrafunctional epoxy resin, naphthol phenolic varnish-type epoxy resin, cresol phenolic varnish-type epoxy resin, dicyclopentadiene-type epoxy resin, triphenol-type epoxy resin, naphthol-type epoxy resin, biphenyl-type epoxy resin, naphthylene ether-type epoxy resin, anthracene-type epoxy resin, bisphenol A-type epoxy resin, bisphenol AF-type epoxy resin, phenol aralkyl-type epoxy resin, tetraphenylethane-type epoxy resin, phenol phthalimide-type epoxy resin, and phenolphthalein-type epoxy resin.

[0057] Specific examples of solid epoxy resins include: DIC's "HP4032H" (naphthalene-type epoxy resin); DIC's "HP-4700" and "HP-4710" (naphthalene-type tetrafunctional epoxy resins); DIC's "N-690" (cresol-phenolic varnish type epoxy resin); DIC's "N-695" (cresol-phenolic varnish type epoxy resin); DIC's "HP-7200," "HP-7200HH," "HP-7200H," and "HP-7200L" (dicyclopentadiene type epoxy resin); DIC's "EXA-7311," "EXA-7311-G3," "EXA-7311-G4," "EXA-7311-G4S," and "HP6000" (naphthyl ether type epoxy resin); and Nippon Kayaku Co., Ltd.'s "EPPN-502H." (Pyrophenol type epoxy resin); "NC7000L" (Naphthol phenolic varnish type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; "NC3000H", "NC3000", "NC3000L", "NC3000FH", and "NC3100" (Biphenyl type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; "ESN475V" and "ESN4100V" (Naphthalene type epoxy resin) manufactured by Nippon Steel Chemical Materials Co., Ltd.; "ESN485" (Naphthol type epoxy resin) manufactured by Nippon Steel Chemical Materials Co., Ltd.; "ESN375" (Dihydroxynaphthalene type epoxy resin) manufactured by Nippon Steel Chemical Materials Co., Ltd.; "YX4000H", "YX4000", "YX4000HK", and "YL7890" (Bis(xylenol) type epoxy resin) manufactured by Mitsubishi Chemical Co., Ltd.; "YL6121" manufactured by Mitsubishi Chemical Co., Ltd. (Biphenyl type epoxy resin); Mitsubishi Chemical Corporation's "YX8800" (anthracite type epoxy resin); Mitsubishi Chemical Corporation's "YX7700" (phenolic aralkyl type epoxy resin); Osaka Gas Chemical Co., Ltd.'s "PG-100" and "CG-500"; Mitsubishi Chemical Corporation's "YX7760" (bisphenol AF type epoxy resin); Mitsubishi Chemical Corporation's "YL7800" (fluorene type epoxy resin); Mitsubishi Chemical Corporation's "1010" (bisphenol A type epoxy resin); Mitsubishi Chemical Corporation's "1031S" (tetraphenylethane type epoxy resin); Nippon Kayaku Co., Ltd.'s "WHR991S" (Phenolic phthalimide type epoxy resin); "EHPE3150" manufactured by DAIICEL; "DE-102" and "DE-103" manufactured by ENEOS; "DCPD-DE" (alicyclic epoxy resin) manufactured by Nippon Materials Technology Co., Ltd., etc. These can be used alone or in combination of two or more.

[0058] When both solid epoxy resin and liquid epoxy resin are used as epoxy resin, the mass ratio of solid epoxy resin to liquid epoxy resin (solid epoxy resin / liquid epoxy resin) is not particularly limited, but is preferably 1 or less, more preferably 0.5 or less, further preferably 0.1 or less, even more preferably 0.05 or less, and particularly preferably 0.01 or less.

[0059] The epoxy equivalent of the epoxy resin is preferably 50 g / eq. to 5000 g / eq., more preferably 50 g / eq. to 3000 g / eq., even more preferably 80 g / eq. to 2000 g / eq., and even more preferably 110 g / eq. to 1000 g / eq. Epoxy equivalent is the mass of resin per equivalent of epoxy groups. This epoxy equivalent can be determined according to JIS K7236.

[0060] From the viewpoint of significantly achieving the desired effects of the present invention, the weight-average molecular weight (Mw) of the epoxy resin is preferably 100 to 5000, more preferably 250 to 3000, and even more preferably 400 to 1500. The weight-average molecular weight of the resin can be determined using gel permeation chromatography (GPC) as a polystyrene equivalent.

[0061] As a resin having free radical polymerizable groups, a compound having an olefinically unsaturated bond can be used. Therefore, a resin having free radical polymerizable groups can have free radical polymerizable groups containing olefinically unsaturated bonds. Examples of free radical polymerizable groups include: vinyl, allyl, 3-cyclohexenyl, 3-cyclopentenyl, 2-vinylphenyl, 3-vinylphenyl, 4-vinylphenyl, and other unsaturated hydrocarbon groups; (meth)acryloyl, maleimide (2,5-dihydro-2,5-dioxo-1H-pyrrole-1-yl), and other α,β-unsaturated carbonyl groups. It should be noted that the term "(meth)acryloyl" includes acryloyl, methacryloyl, and combinations thereof. A resin having free radical polymerizable groups may contain one free radical polymerizable group per molecule, but preferably two or more. A resin having free radical polymerizable groups can be used alone or in combination of two or more.

[0062] Examples of resins having free radical polymerizable groups include (meth)acrylic resins, allyl resins, acrylic resins, styrene resins, and maleimide resins. Among these, (meth)acrylic resins are preferred as resins having free radical polymerizable groups.

[0063] (Meth)acrylic resin is, for example, a resin having one or more, preferably two or more, acryloyl groups and / or methacryloyl groups. Examples of (meth)acrylate resins include, for example, cyclohexane-1,4-diethanol di(meth)acrylate, cyclohexane-1,3-diethanol di(meth)acrylate, tricyclodecane-diethanol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,8-octanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolethane tri(meth)acrylate, glycerol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, and other low molecular weight (molecular weight less than 1000) aliphatic (meth)acrylate compounds; dialkyldiol di(meth)acrylate, 3,6-dioxane-1,8-octanediol di(meth)acrylate, etc. Low molecular weight (molecular weight less than 1000) ether-containing (meth)acrylate compounds such as methacrylates, 3,6,9-trioxaundecane-1,11-diol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, 9,9-bis[4-(2-acryloyloxyethoxy)phenyl]fluorene, ethoxylated bisphenol A di(meth)acrylate, propoxylated bisphenol A di(meth)acrylate, etc.; low molecular weight (molecular weight less than 1000) isocyanurate-containing (meth)acrylate compounds such as tri(3-hydroxypropyl)isocyanurate tri(meth)acrylate, tri(2-hydroxyethyl)isocyanurate tri(meth)acrylate, ethoxylated isocyanuric acid tri(meth)acrylate, etc.; high molecular weight (molecular weight greater than 1000) acrylate compounds such as (meth)acrylate-modified polyphenylene ether resin, etc. Commercially available (meth)acrylic resins include, for example: "A-DOG" (dialkyldiol diacrylate) manufactured by Shin-Nakamura Chemical Industry Co., Ltd.; "DCP-A" (tricyclodecanediethanol diacrylate) and "DCP" (tricyclodecanediethanol dimethacrylate) manufactured by Kyoeisha Chemical Co., Ltd.; "KAYARAD R-684" (tricyclodecanediethanol diacrylate) and "KAYARAD R-604" (dialkyldiol diacrylate) manufactured by Nippon Kayaku Co., Ltd.; and "SA9000" and "SA9000-111" (methacrylic acid modified polyphenylene ether) manufactured by SABIC Co., Ltd.

[0064] Allyl resins are, for example, compounds having one or more, preferably two or more, allyl groups. Examples of allyl resins include: allyl biphenyl ester, triallyl trimellitate, diallyl phthalate, diallyl isophthalate, diallyl terephthalate, diallyl 2,6-naphthalenedicarboxylate, diallyl 2,3-naphthalenedicarboxylate, and other aromatic carboxylic acid allyl ester compounds; 1,3,5-triallyl isocyanurate, 1,3-diallyl-5-glycidyl isocyanurate, and other isocyanurate allyl ester compounds; 2,2-bis(2,3-diphenyltriphenyl)isocyanurate, etc. Aromatic allyl compounds containing epoxy groups, such as [3-allyl-4-(glycidyloxy)phenyl]propane; aromatic allyl compounds containing benzo[3-allyl-4-(3,4-dihydro-2H-1,3-benzo[3-yl]phenyl]methane, such as benzo[3-allyl-4-(3,4-dihydro-2H-1,3-benzo[3-yl]phenyl]methane; aromatic allyl compounds containing ether groups, such as 1,3,5-triallyl etherbenzene; allyl silane compounds, such as diallyldiphenylsilane; resins containing multiple benzene rings and multiple allyl groups, etc. Commercially available allyl resins include, for example: TAIC (1,3,5-triallyl isocyanurate) manufactured by Nippon Kasei Corporation; DAD (dallyl biphenyl dicarboxylate) manufactured by Nisshoku Techno Fine Chemical Co., Ltd.; TRIAM-705 (triallyl trimellitate) manufactured by Fujifilm and Koujun Pharmaceutical Co., Ltd.; DAND (dallyl 2,3-naphthalenedicarboxylate) manufactured by Nisshoku Techno Fine Chemical Co., Ltd.; RE-810NM (2,2-bis[3-allyl-4-(glycidyloxy)phenyl]propane) manufactured by Nippon Kayaku Co., Ltd.; DA-MGIC (1,3-diallyl-5-glycidyl isocyanurate) manufactured by Shikoku Kasei Kogyo Co., Ltd.; and NE-V-1100-70T (a resin containing multiple benzene rings and multiple allyl groups) manufactured by DIC Co., Ltd.

[0065] Acrylic resins are, for example, compounds having one or more, preferably two or more, propylene groups (1-propylene groups). As a propylene resin, it can be a monomer or an oligomer, as long as it has one or more propylene groups in one molecule. Commercially available propylene resins include Tosoh Corporation's "Petrotack 70" and "Petrotack 90," among others.

[0066] Styrene resin is, for example, a compound having one or more, preferably two or more, vinyl groups directly bonded to an aromatic carbon atom. Examples of styrene resins include: low molecular weight (molecular weight less than 1000) styrene resins such as divinylbenzene, 2,4-divinyltoluene, 2,6-divinylnaphthalene, 1,4-divinylnaphthalene, 4,4'-divinylbiphenyl, 1,2-bis(4-vinylphenyl)ethane, 2,2-bis(4-vinylphenyl)propane, and bis(4-vinylphenyl) ether; and high molecular weight (molecular weight 1000 or more) styrene resins such as vinylbenzyl modified polyphenylene ether resin and styrene-divinylbenzene copolymer. Commercially available styrene resins include, for example: “ODV-XET(X03)”, “ODV-XET(X04)”, and “ODV-XET(X05)” (styrene-divinylbenzene copolymer) manufactured by Nippon Steel Chemical Materials Co., Ltd.; and “OPE-2St”, “OPE-2St 1200”, and “OPE-2St 2200” (vinyl benzyl modified polyphenylene ether resin) manufactured by Mitsubishi Gas Chemical Co., Ltd.

[0067] Maleimide resins are, for example, compounds having one or more, preferably two or more, maleimide groups. Maleimide resins can be aliphatic maleimide resins containing an aliphatic amine skeleton, or aromatic maleimide resins containing an aromatic amine skeleton. Commercially available maleimide resins include, for example: "SLK-2600" and "SLK-6895-T90" manufactured by Shin-Etsu Chemical Industry Co., Ltd.; "BMI-1500", "BMI-1700", "BMI-3000J", "BMI-689", and "BMI-2500" (maleimide resins containing dimeric diamine structures) manufactured by Designer Molecules Inc.; "BMI-6100" (aromatic maleimide resin) manufactured by Designer Molecules Inc.; "MIR-5000-60T" and "MIR-3000-70MT" (biphenyl aralkyl type maleimide resin) manufactured by Nippon Kayaku Co., Ltd.; "BMI-70" and "BMI-80" manufactured by KI Chemical Co., Ltd.; and "BMI-2300" and "BMI-TMH" manufactured by Daiwa Chemical Industry Co., Ltd. Alternatively, the maleimide resin disclosed in Japanese Inventors Association Publication No. 2020-500211 (maleimide resin containing an indane ring skeleton) can be used as the maleimide resin.

[0068] As a phenolic resin, a resin having one or more, preferably two or more, phenolic hydroxyl groups in one molecule can be used. A phenolic hydroxyl group refers to a hydroxyl group bonded to an aromatic ring such as a benzene ring or a naphthalene ring. Preferably, the phenolic resin is a biphenyl-type phenolic resin, a naphthyl phenolic resin, a phenolic varnish-type phenolic resin, a naphthylene ether-type phenolic resin, or a phenolic resin containing a triazine skeleton.

[0069] Specific examples of phenolic resins include: biphenyl-type phenolic resins such as "MEH-7700", "MEH-7810", and "MEH-7851" (manufactured by Meiwa Kasei Corporation); naphthalene-type phenolic resins such as "NHN", "CBN", and "GPH" (manufactured by Nippon Kayaku Co., Ltd.); "SN170", "SN180", "SN190", "SN475", "SN485", "SN495", "SN375", and "SN395" (manufactured by Nippon Steel Chemical Materials Co., Ltd.); "EXB9500" (manufactured by DIC Corporation); phenolic varnish-type phenolic resin "TD2090" (manufactured by DIC Corporation); and naphthylene ether-type phenolic resin "EXB-6000" (manufactured by DIC Corporation). Specific examples of phenolic resins containing a triazine backbone include: "LA3018", "LA7052", "LA7054", and "LA1356" (manufactured by DIC Corporation).

[0070] As an active ester resin, a resin having one or more active ester groups per molecule can be used. Among these, compounds having two or more highly reactive ester groups per molecule, such as phenolic esters, thiophenolic esters, N-hydroxyamine esters, and heterocyclic hydroxyl compounds, are preferred as active ester resins. This active ester resin is preferably a resin obtained by the condensation reaction of a carboxylic acid compound and / or a thiocarboxylic acid compound with a hydroxyl compound and / or a thiol compound. In particular, from the viewpoint of improving heat resistance, this active ester resin is preferably an active ester resin obtained from a carboxylic acid compound and a hydroxyl compound, and more preferably an active ester resin obtained from a carboxylic acid compound and a phenolic compound and / or a naphthol compound. Examples of carboxylic acid compounds include, for example, benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, and pyromellitic acid. Examples of phenolic or naphthol compounds include: hydroquinone, resorcinol, bisphenol A, bisphenol F, bisphenol S, phenolphthalein, methylated bisphenol A, methylated bisphenol F, methylated bisphenol S, phenol, o-cresol, m-cresol, p-cresol, catechol, α-naphthol, β-naphthol, 1,5-dihydroxynaphthol, 1,6-dihydroxynaphthol, 2,6-dihydroxynaphthol, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucinol, benzotriol, dicyclopentadiene-type diphenol compounds, and phenolic varnishes. Here, "dicyclopentadiene-type diphenol compounds" refers to diphenol compounds obtained by the condensation of two molecules of phenol with one molecule of dicyclopentadiene.

[0071] Commercially available reactive ester resins include, for example: "EXB9451", "EXB9460", "EXB9460S", "EXB-8000L", "EXB-8000L-65M", "EXB-8000L-65TM", "HPC-8000L-65TM", "HPC-8000", and "HPC-8000-65T" (manufactured by DIC Corporation), which contain a dicyclopentadiene-type diphenol structure; "HP-C-8151-62T", "EXB-8100L-65T", "EXB-8150-60T", "EXB-8150-62T", "EXB-9416-70BK", "HPC-8150-62T", and "EXB-8" (manufactured by DIC Corporation), which contain a naphthalene structure; and "EXB9401", a phosphorus-containing reactive ester resin. (Manufactured by DIC Corporation); "DC808" (manufactured by Mitsubishi Chemical Corporation), an active ester resin for phenolic varnishes, comprising acetylated compounds; "YLH1026", "YLH1030", and "YLH1048" (manufactured by Mitsubishi Chemical Corporation), an active ester resin for phenolic varnishes, comprising benzoyl compounds; and "PC1300-02-65MA" (manufactured by AIR WATER Corporation), an active ester resin containing styrene and naphthalene structures. Active ester resins can be used alone or in combination of two or more.

[0072] As a carbodiimide resin, a resin having one or more, preferably two or more, carbodiimide structures in one molecule can be used. Examples of carbodiimide resins include: aliphatic dicarbodiimides such as tetramethylene-bis(tert-butylcarbodiimide) and cyclohexane-bis(methylene-tert-butylcarbodiimide); aromatic dicarbodiimides such as phenylene-bis(xylylcarbodiimide); aliphatic polycarbodiimides such as polyhexamethylenecarbodiimide, polytrimethylhexamethylenecarbodiimide, polycyclohexylcarbodiimide, poly(methylene dicyclohexylcarbodiimide), and poly(isophorone carbodiimide); poly(phenylenecarbodiimide), poly(phenylenecarbodiimide), etc. Polycarbodiimides, including naphthyl carbodiimide, poly(toluene-based carbodiimide), poly(methyldiisopropylphenylcarbodiimide), poly(triethylphenylcarbodiimide), poly(diethylphenylcarbodiimide), poly(triisopropylphenylcarbodiimide), poly(diisopropylphenylcarbodiimide), poly(phenylene dimethylcarbodiimide), poly(tetramethylphenylene dimethylcarbodiimide), poly(methylene diphenylcarbodiimide), poly[methylene bis(methylphenylene)carbodiimide], and other aromatic polycarbodiimides. Commercially available carbodiimide resins include, for example, those manufactured by Nisshinbo Chemical Co., Ltd., such as "CARBODILITE V-02B", "CARBODILITE V-03", "CARBODILITE V-04K", "CARBODILITE V-07", and "CARBODILITE V-09"; and those manufactured by LANXESS, such as "Stabaxol P", "Stabaxol P400", and "Hycasyl 510". Carbodiimide resins can be used alone or in combination of two or more types.

[0073] As an anhydride resin, resins having one or more, preferably two or more, anhydride groups in one molecule can be used. Examples of anhydride resins include: phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylnadic anhydride, hydrogenated methylnadic anhydride, trialkyltetrahydrophthalic anhydride, dodecenylsuccinic anhydride, 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, trimellitic anhydride, pyromellitic anhydride, and diphenylmethane. Polymer-type anhydrides include ketone tetracarboxylic dianhydride, biphenyl tetracarboxylic dianhydride, naphthalene tetracarboxylic dianhydride, oxydiphthalic dianhydride, 3,3'-4,4'-diphenylsulfone tetracarboxylic dianhydride, 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphtho[1,2-C]furan-1,3-dione, ethylene glycol bis(triphenylene phthalate), and styrene-maleic acid resin copolymerized from styrene and maleic acid. Commercially available anhydride resins include: "HNA-100", "MH-700", "MTA-15", "DDSA", and "OSA" manufactured by Shin Nippon Rikka Co., Ltd.; "YH-306" and "YH-307" manufactured by Mitsubishi Chemical Co., Ltd.; and "HN-2200" and "HN-5500" manufactured by Resonac Co., Ltd. Acid anhydride resins can be used alone or in combination of two or more.

[0074] As an amine resin, a resin having one or more, preferably two or more, amino groups in one molecule can be used. Examples of amine resins include aliphatic amines, polyether amines, alicyclic amines, and aromatic amines, with aromatic amines being preferred. Primary or secondary amines are preferred, with primary amines being more preferred. Specific examples of amine resins include: 4,4'-methylenebis(2,6-dimethylaniline), 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, m-phenylenediamine, m-phenylenediamine, diethyltoluenediamine, 4,4'-diaminodiphenyl ether, 3,3'-dimethyl-4,4'-diaminobiphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dihydroxybiphenylamine, and 2,2-bis(3-amino-4-hydroxybenzene). 2,2-bis(4-aminophenyl)propane, 2,2-bis(4-(4-aminophenoxy)phenyl)propane, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, bis(4-(4-aminophenoxy)phenyl)sulfone, bis(4-(3-aminophenoxy)phenyl)sulfone, etc. Commercially available amine resins can be used, such as: SEIKA ACURE-S manufactured by SEIKA Corporation; KAYABOND C-200S, KAYABOND C-100, KAYAHARD AA, KAYAHARD AB, and KAYAHARD AS manufactured by Nippon Kayaku Co., Ltd.; and EPIKURE W manufactured by Mitsubishi Chemical Co., Ltd. Amine resins can be used alone or in combination of two or more.

[0075] As benzo[a]azine resins, resins having one or more, preferably two or more, benzo[a]azine rings in one molecule can be used. Specific examples of benzo[a]azine resins include: "JBZ-OP100D" and "ODA-BOZ" manufactured by JFE Chemical Co., Ltd.; "HFB2006M" manufactured by Showa Polymer Co., Ltd.; and "Pd" and "Fa" manufactured by Shikoku Chemical Industry Co., Ltd. A single benzo[a]azine resin can be used alone, or two or more can be used in combination.

[0076] As a cyanate ester resin, a resin having one or more, preferably two or more, cyanate ester groups in one molecule can be used. Examples of cyanate ester resins include: bisphenol A dicyanate, polyphenol cyanate (oligomeric (3-methylene-1,5-phenylene cyanate)), 4,4'-methylenebis(2,6-dimethylphenyl cyanate), 4,4'-ethoxydiphenyl dicyanate, hexafluorobisphenol A dicyanate, 2,2-bis(4-cyanate-phenyl)propane, 1,1-bis(4-cyanate-phenylmethane), bis(4-cyanate-3,5-dimethylphenyl)methane, 1,3-bis(4-cyanate-phenyl-1-(methylethoxy))benzene, bis(4-cyanate-phenyl) sulfide and bis(4-cyanate-phenyl) ether, etc., difunctional cyanate ester resins, polyfunctional cyanate ester resins derived from phenolic varnish and cresol varnish, etc., and prepolymers formed by partially triazinizing these cyanate ester resins, etc. Specific examples of cyanate ester resins include: "PT30" and "PT60" (both phenolic varnish-type multifunctional cyanate ester resins) manufactured by Arxada, "BA230" and "BA230S75" (prepolymers of bisphenol A dicyanate that have undergone partial or complete triazinization to become trimers), etc. A single cyanate ester resin can be used alone, or two or more can be used in combination.

[0077] Examples of thiol resins include trimethylolpropane tris(3-mercaptopropionate), pentaerythritol tetra(3-mercaptobutyrate), and tris(3-mercaptopropyl)isocyanurate. A single thiol resin can be used alone, or two or more can be used in combination.

[0078] As silicone resins, resins having one or more, preferably two or more, silanol groups and / or alkoxysilyl groups within one molecule can be used. Examples of commercially available silicone resins include: "KR-220L", "KR-220LP", "KR-242P", "KR-251", "X-40-2406M", "KR-112", "KR-211", "KR-212", "KR-255", "KR-271", "KR-282", "KR-300", "KR-311", and "X-48-1030" manufactured by Shin-Etsu Chemical Co., Ltd. "X-40-2667A", "X-40-2756", "KR-480", "ES-1001N", "ES-1002T", "ES-1023", "X-41-1610", "KR- 5206", "KR-5230", "KR-5234", "KR-5235", "KC-89S", "KR-515", "KR-500", "X-40-9225", "X-40-9 246", "X-40-9250", "X-88-1004", "X-88-1007", "X-48-1500", "X-48-1600", "KR-401N", "X-40-9 227", "KR-510", "KR-213", "X-40-9312", "KR-4000G", "KR-4000F2", "KR-400", "X-40-2327", "KR The product names include "-401", "X-40-2450", "X-40-9300", "X-40-9301", "KR-517", "X-24-9590", "KR-516", "KR-518", "KR-519", "KR-513", "X-40-9296", "KR-511", "KR-2710", "KR-470", "X-40-2678", and "X-40-2669". Silicone resins can be used alone or in combination of two or more types.

[0079] The core resin composition preferably comprises one or more resins selected from epoxy resin, (meth)acrylic resin, phenolic resin and silicone resin.

[0080] The core resin composition may optionally contain a cyclic carbonate compound. A cyclic carbonate compound is a compound having carbonate bonds (-OC(=O)-O-) in a cyclic structure. The cyclic carbonate compound does not contain any components equivalent to the thermosetting resin described above. One cyclic carbonate compound may be used alone, or two or more may be used in combination.

[0081] In cyclic carbonate compounds, the number of atoms forming the cyclic structure is preferably 5 or 6. Therefore, cyclic carbonate compounds are preferably 5-membered ring cyclic carbonate compounds and / or 6-membered ring cyclic carbonate compounds.

[0082] Cyclic carbonate compounds may have substituents. Examples of substituents that may be present in cyclic carbonate compounds include: halogen atoms, alkyl groups with 1 to 6 carbon atoms that can be substituted by halogen atoms, alkenyl groups with 2 to 6 carbon atoms that can be substituted by halogen atoms, and alkynyl groups with 2 to 6 carbon atoms that can be substituted by halogen atoms.

[0083] Cyclic carbonate compounds can be commercially available, such as: "DXC" (5,5-dimethyl-4-(propane-2-yl)-1,3-dialkyl-2-one) and "DEDPO" (5,5-diethyl-1,3-dialkyl-2-one) manufactured by JNC Corporation; and "ethylene carbonate" (1,3-dioxolane-2-one) manufactured by Tokyo Chemical Industry Co., Ltd.

[0084] The core resin composition may optionally include a thermosetting accelerator. The thermosetting accelerator functions, for example, as a catalyst or a thermal free radical generator, thereby promoting the reaction of the aforementioned thermosetting resin and accelerating the thermosetting of the core resin composition. The thermosetting accelerator does not contain components equivalent to the aforementioned thermosetting resin and cyclic carbonate compounds. A single thermosetting accelerator may be used alone, or two or more may be used in combination.

[0085] Examples of thermosetting accelerators include: phosphorus-based thermosetting accelerators, urea-based thermosetting accelerators, guanidine-based thermosetting accelerators, imidazole-based thermosetting accelerators, metal-based thermosetting accelerators, and amine-based thermosetting accelerators. Additionally, thermal free radical generators can be used as thermosetting accelerators.

[0086] Examples of phosphorus-based curing accelerators include: triphenylphosphine, tricyclohexylphosphine, tributylphosphine, methyldiphenylphosphine, phosphorus borate compounds, tetraphenylphosphine tetraphenylborate, a salt of tetra-n-butylphosphine and N-acetylglycine, n-butylphosphine tetraphenylborate, tetrabutylphosphine decanoate, (4-methylphenyl)triphenylphosphine thiocyanate, tetraphenylphosphine thiocyanate, and butyltriphenylphosphine thiocyanate. Commercially available phosphorus-based curing accelerators are also available, such as "TBP-DA" manufactured by Beixing Chemical Industry Co., Ltd., and "AiL-01" manufactured by Ajinomoto Fine-Techno Co., Ltd. A single phosphorus-based curing accelerator can be used, or two or more can be used in combination.

[0087] Examples of urea-based thermosetting accelerators 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- Aromatic dimethylureas such as (dimethylphenyl)-1,1-dimethylurea, 3-(4-isopropylphenyl)-1,1-dimethylurea, 3-(4-methoxyphenyl)-1,1-dimethylurea, 3-(4-nitrophenyl)-1,1-dimethylurea, 3-[4-(4-methoxyphenoxy)phenyl]-1,1-dimethylurea, 3-[4-(4-chlorophenoxy)phenyl]-1,1-dimethylurea, 3-[3-(trifluoromethyl)phenyl]-1,1-dimethylurea, N,N-(1,4-phenylene)bis(N',N'-dimethylurea), N,N-(4-methyl-1,3-phenylene)bis(N',N'-dimethylurea) [toluenebisdimethylurea], etc. Urea-based curing accelerators can be used alone or in combination of two or more.

[0088] Examples of guanidine-based curing accelerators include: dicyandiamide, 1-methylguanidine, 1-ethylguanidine, 1-cyclohexylguanidine, 1-phenylguanidine, 1-(o-tolyl)guanidine, dimethylguanidine, diphenylguanidine, trimethylguanidine, tetramethylguanidine, pentamethylguanidine, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene, 1-methylbiguanidine, 1-ethylbiguanidine, 1-n-butylbiguanidine, 1-n-octadecylbiguanidine, 1,1-dimethylbiguanidine, 1,1-diethylbiguanidine, 1-cyclohexylbiguanidine, 1-allylbiguanidine, 1-phenylbiguanidine, and 1-(o-tolyl)biguanidine. A single guanidine-based curing accelerator can be used, or two or more can be used in combination.

[0089] Examples of imidazole-based curing accelerators include: 2-methylimidazolium, 2-undecylimidazolium, 2-heptadecylimidazolium, 1,2-dimethylimidazolium, 2-ethyl-4-methylimidazolium, 1,2-dimethylimidazolium, 2-ethyl-4-methylimidazolium, 2-phenylimidazolium, 2-phenyl-4-methylimidazolium, 1-benzyl-2-methylimidazolium, 1-benzyl-2-phenylimidazolium, 1-cyanoethyl-2-methylimidazolium, 1-cyanoethyl-2-undecylimidazolium, 1-cyanoethyl-2-ethyl-4-methylimidazolium, 1-cyanoethyl-2-phenylimidazolium, 1-cyanoethyl-2-undecylimidazolium trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino-6-[2'-methylimidazolium-(1 [1']-ethyl-triazine, 2,4-diamino-6-[2'-undecylimidazolyl-(1')]-ethyl-triazine, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-triazine isocyanuric acid adduct, 2-phenylimidazolyl isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazolium, 2-phenyl-4-methyl-5-hydroxymethylimidazolium, 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 with epoxy resins. As imidazole-based curing accelerators, commercially available products can be used, such as: "1B2PZ", "2E4MZ", "2MZA-PW", "2MZ-OK", "2MA-OK", "2MA-OK-PW", "2P4MZ", "2PHZ", "2PHZ-PW", "2P4MHZ-PW", "Cl1Z", "Cl1Z-CN", "Cl1Z-CNS", and "C11Z-A" manufactured by Shikoku Chemical Co., Ltd.; and "P200-H50" manufactured by Mitsubishi Chemical Co., Ltd. Imidazole-based curing accelerators can be used alone or in combination of two or more.

[0090] 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) and cobalt(III) acetylacetone, organocopper complexes such as copper(II) acetylacetone, organozinc complexes such as zinc(II) acetylacetone, organoiron complexes such as iron(III) acetylacetone, organonickel complexes such as nickel(II) acetylacetone, and organomanganese complexes such as manganese(II) acetylacetone. Examples of organometallic salts include zinc octoate, tin octoate, zinc naphthenate, cobalt naphthenate, tin stearate, and zinc stearate. Metal-based curing accelerators can be used alone or in combination of two or more.

[0091] Examples of amine-based curing accelerators include trialkylamines such as triethylamine and tributylamine, 4-dimethylaminopyridine, benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, and 1,8-diazabicyclo(5,4,0)-undecene. Commercially available amine-based curing accelerators can be used, such as "DMAP" manufactured by Tokyo Chemical Industry Co., Ltd. Amine-based curing accelerators can be used alone or in combination of two or more.

[0092] Examples of thermal free radical generators include: dialkyl peroxides such as di-tert-butyl peroxide, dicumyl peroxide, and tert-hexyl peroxide-2-ethylhexanoate; diacyl peroxides such as lauroyl peroxide, benzoyl peroxide, benzoyl peroxide, and toluyl peroxide; peresters such as tert-butyl peracetate, tert-butyl peroctanoate, and tert-butyl peroxybenzoate; ketone peroxides; peroxide carbonates; peroxide ketals such as 1,1-di(tert-pentylperoxy)cyclohexane; and 2,2'-azobis(2,4-dimethylpentanonitrile), 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2-methylbutyronitrile), and 2,2'-azobis(4- Azo nitrile compounds such as methoxy-2,4-dimethylpentanonitrile; azo amide compounds such as 2,2'-azobis{2-methyl-N-[1,1-bis(hydroxymethyl)-2-hydroxyethyl]propionamide}; azomididine compounds such as 2,2'-azobis(2-amidinylpropane) dihydrochloride and 2,2'-azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride; azoalkane compounds such as 2,2'-azobis(2,4,4-trimethylpentane) and 4,4'-azobis(4-cyanopentanoic acid); azo compounds with an oxime skeleton such as 2,2'-azobis(2-methylpropionamidoxime); and azo compounds such as 2,2'-azobis(isobutyric acid) dimethyl ester. Thermal free radical generators can be used alone or in combination of two or more.

[0093] The core resin composition may optionally include a thermoplastic resin. The thermoplastic resin does not contain components equivalent to the thermosetting resin, cyclic carbonate compound, and thermosetting accelerator described above. A single thermoplastic resin may be used alone, or two or more may be used in combination.

[0094] As a thermoplastic resin, a resin that exhibits plasticity upon heating can be used. Examples of thermoplastic resins include: phenoxy resins, polyimide resins, polyvinyl acetal resins, polyolefin resins, polybutadiene resins, polyamide-imide resins, polyether-imide resins, polysulfone resins, polyethersulfone resins, polyphenylene ether resins, polycarbonate resins, polyetheretherketone resins, polyester resins, etc.

[0095] Examples of phenoxy resins include those having one or more skeletons selected from the following: bisphenol A skeleton, bisphenol F skeleton, bisphenol S skeleton, bisphenol acetophenone skeleton, phenolic varnish skeleton, biphenyl skeleton, fluorene skeleton, dicyclopentadiene skeleton, norbornene skeleton, naphthalene skeleton, anthracene skeleton, adamantane skeleton, terpene skeleton, and trimethylcyclohexane skeleton. The terminal group of the phenoxy resin can be any functional group such as a phenolic hydroxyl group or an epoxy group.

[0096] Specific examples of phenoxy resins include: "1256" and "4250" (both phenoxy resins containing a bisphenol A backbone) manufactured by Mitsubishi Chemical Corporation; "YX8100" (a phenoxy resin containing a bisphenol S backbone) manufactured by Mitsubishi Chemical Corporation; "YX6954" (a phenoxy resin containing a bisphenol acetophenone backbone) manufactured by Mitsubishi Chemical Corporation; "FX280" and "FX293" manufactured by Nippon Steel Chemical Materials Co., Ltd.; and "YX7200B35", "YL7500BH30", "YX6954BH30", "YX7553BH30", "YL7769BH30", "YL6794", "YL7213", "YL7290", and "YL7482" manufactured by Mitsubishi Chemical Corporation. Phenoxy resins can be used alone or in combination of two or more.

[0097] Specific examples of polyimide resins include: "SLK-6100" manufactured by Shin-Etsu Chemical Co., Ltd.; and "RIKACOAT SN20" and "RIKACOAT PN20" manufactured by Shin Nippon Rikka Co., Ltd. Polyimide resins can be used alone or in combination of two or more types.

[0098] Examples of polyvinyl acetal resins include polyvinyl formal resin and polyvinyl butyral resin, with polyvinyl butyral resin being preferred. Specific examples of polyvinyl acetal resins include the S-LEC BH series, BX series (e.g., BX-5Z), KS series (e.g., KS-1), BL series, and BM series manufactured by Sekisui Chemicals Co., Ltd. A single polyvinyl acetal resin can be used alone, or two or more can be used in combination.

[0099] Examples of polyolefin resins include: low-density polyethylene, ultra-low-density polyethylene, high-density polyethylene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, ethylene-methyl acrylate copolymer, and other ethylene-based copolymers; polyolefin polymers such as polypropylene and ethylene-propylene block copolymers. A single polyolefin resin can be used alone, or two or more can be used in combination.

[0100] Examples of polybutadiene resins include: resins containing a hydrogenated polybutadiene backbone, hydroxyl-containing polybutadiene resins, phenolic hydroxyl-containing polybutadiene resins, carboxyl-containing polybutadiene resins, anhydride-containing polybutadiene resins, epoxy-containing polybutadiene resins, isocyanate-containing polybutadiene resins, urethane-containing polybutadiene resins, and polyphenylene ether-polybutadiene resins. Polybutadiene resins can be used alone or in combination of two or more types.

[0101] Specific examples of polyamide-imide resins include "VYLOMAX HR11NN" and "VYLOMAX HR16NN" manufactured by Toyobo Co., Ltd. Other examples include modified polyamide-imide resins such as "KS9100" and "KS9300" (polyamide-imide containing a polysiloxane backbone) manufactured by Hitachi Chemical Co., Ltd. Polyamide-imide resins can be used alone or in combination of two or more types.

[0102] Specific examples of polyethersulfone resins include "PES5003P" manufactured by Sumitomo Chemical Co., Ltd. Polyethersulfone resins can be used alone or in combination of two or more types.

[0103] Specific examples of polysulfone resins include polysulfones "P1700" and "P3500" manufactured by Solvay Advanced Polymers. Polysulfone resins can be used alone or in combination of two or more types.

[0104] Specific examples of polyphenylene ether resins include "NORYL SA90" manufactured by SABIC. Polyphenylene ether resins can be used alone or in combination of two or more types. Specific examples of polyetherimide resins include "ULTEM" manufactured by GE. Polyetherimide resins can be used alone or in combination of two or more types.

[0105] In addition to the components mentioned above, the core resin composition may further contain other additives. Examples of such additives include: inorganic fillers, organic fillers, surface treatment agents, organometallic compounds, colorants, polymerization inhibitors, homogenizers, thickeners, defoamers, ultraviolet absorbers, adhesion enhancers, bonding agents, antioxidants, fluorescent whitening agents, surfactants, flame retardants, dispersants, stabilizers, photopolymerization initiators, photopolymerization initiation aids, and photosensitizers. Other additives may be used individually or in combination of two or more.

[0106] The core resin composition may contain a solvent as a volatile component. Examples of solvents include: ketones such as methyl ethyl ketone (MEK) and cyclohexanone; aromatic hydrocarbons such as xylene and tetramethylbenzene; glycol ethers 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; esters such as ethyl acetate, butyl acetate, butyl cellosolve acetate, carbitol acetate, and ethyl carbitol acetate; aliphatic hydrocarbons such as octane and decane; petroleum-based solvents such as petroleum ether, naphtha, hydrogenated naphtha, and solvent naphtha; and ether ester solvents such as propylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl carbitol acetate, γ-butyrolactone, and methyl methoxypropionate. A single solvent may be used, or two or more may be used in combination.

[0107] The core resin composition can be manufactured, for example, by a manufacturing method that includes mixing the above-mentioned components. The components can be mixed partially or entirely simultaneously, or sequentially. During the mixing of the components, the temperature can be appropriately adjusted, thus allowing for temporary or continuous heating and / or cooling. Furthermore, stirring or agitation can be performed during the mixing of the components. Moreover, degassing can be carried out under low-pressure conditions such as vacuum.

[0108] <Coating Resin Composition> In the method for manufacturing the optical waveguide of the present invention, the coating resin composition comprises a thermosetting resin and / or a photocurable resin. Preferably, the coating resin composition comprises a thermosetting resin.

[0109] The thermosetting resin that may be included in the coating resin composition, including within an appropriate range, is the same as the thermosetting resin included in the core resin composition. Therefore, when the coating resin composition includes a thermosetting resin, the coating resin composition preferably includes one or more resins selected from epoxy resin, (meth)acrylic resin, phenolic resin, and silicone resin.

[0110] When the coating resin composition contains a thermosetting resin, the coating resin composition may optionally contain a cyclic carbonate compound. The cyclic carbonate compound that may be included in the coating resin composition is the same as that that may be included in the core resin composition.

[0111] When the coating resin composition contains a thermosetting resin, the coating resin composition may optionally contain a thermosetting accelerator. The thermosetting accelerator that may be included in the coating resin composition is the same as that that may be included in the core resin composition.

[0112] When the coating resin composition contains a thermosetting resin, the coating resin composition may optionally contain a thermoplastic resin. The thermoplastic resin that may be included in the coating resin composition is the same as the thermoplastic resin that may be included in the core resin composition.

[0113] The photocurable resin that can be included in the coating resin composition can be a resin that can be cured upon exposure. Examples of photocurable resins include free radical polymerizable resins. Additionally, examples of photocurable resins include resins that can be developed with a developer. One type of photocurable resin can be used alone, or two or more types can be used in combination.

[0114] Regarding resins with free radical polymerizable groups that are used as photocurable resins, the components described in the thermosetting resin section can be used. Furthermore, from the viewpoint that they can be developed with alkaline developer, resins with free radical polymerizable groups that are used as photocurable resins are preferably resins having olefinic unsaturated bonds and carboxyl groups.

[0115] Resins having olefinic unsaturated bonds and carboxyl groups can be combined to have free radical polymerizable groups containing olefinic unsaturated bonds and carboxyl groups. Examples of free radical polymerizable groups include the groups described in the section on resins having free radical polymerizable groups as thermosetting resins. Among these, (meth)acryloyl groups are preferred as free radical polymerizable groups. The number of free radical polymerizable groups per molecule of this resin can be one or two. When each molecule of this resin contains two or more free radical polymerizable groups, these free radical polymerizable groups can be the same or different. Furthermore, the number of carboxyl groups per molecule of this resin can be one or two.

[0116] Regarding the resin that can be developed with a developer as a photocurable resin, conventionally known resins used in forming the solder resist layer of a printed wiring board can be used. Examples of resins that can be developed with a developer include: alkali-soluble resins having phenolic hydroxyl groups within the molecule, polybenzo[a]azole precursor resins, polyimide precursors, p-hydroxystyrene / styrene copolymers, (meth)acrylic resins, etc. Preferably, the resin that can be developed with a developer contains one or more selected from alkali-soluble resins having phenolic hydroxyl groups within the molecule, polyimide precursors, polybenzo[a]azole precursor resins, and acrylic resins. One type of resin that can be developed with a developer can be used alone, or two or more types can be used in combination.

[0117] Examples of alkali-soluble resins containing phenolic hydroxyl groups within the molecule include: Asahi Organic Materials Co., Ltd.'s "TR4020G"; Asahi Organic Materials Co., Ltd.'s "TR4050G", "TR4080G", "TR5020G", "TR5050G", "TR6020G", "TR6050G", and "TR6080G" AV LIGHT series; Sumitomo Bakelite's photoresist resin series; Gunei Chemical Co., Ltd.'s Resitop series; DIC's "PR-30-40P", "PR-100L", "PR-100H", "PR-50", "PR-55", "PR-56-1", "PR-56-2", "WR-101", "WR-102", "WR-103", and "WR-104" PHENOLITE series; and Lignyte's... "LF-100", "LF-110", "LF-120", "LF-200", "LF-400", "LF-500"; Base resin series for photoresists manufactured by Meiwa Chemical Co., Ltd.; "MEHC-7851SS", "MEHC-78004S", "MEHC-7851-SS", "MEHC-7851-S", "MEHC-7851-M", "MEHC-7851-H", "MEHC-7800-4S", "MEHC-78" manufactured by Meiwa Chemical Co., Ltd. 00-SS, MEHC-7800-S, MEHC-7800-M, MEHC-7800-H; GPH-65, GPH-103, MEHC-7841-4S manufactured by Nippon Kayaku Co., Ltd.; BisE, BisP-TMC manufactured by Honshu Chemical Co., Ltd.; BisA, BisF, BisP-M, BisP-AP, BisP-MIBK, BisP-B, Bis-Z, BisP-CP, o,o'-BPF, BisP-IOTD, BisP-IBTD, BisP-DED, BisP-BA, Bis-C, Bis26X-A, BisOPP-A, BisOTBP-A, BisOCHP―A, BisOFP-A, BisOC-Z, BisOC-FL, BisOC-CP, BisOCHP-Z, Methylenebis P-CR", "TM-BPF", "BisOC-F", "Bis3M6B-IBTD", "BisOC-IST", "BisP-IST", "BisP-PRM", "BisP-LV", etc.Alkali-soluble resins with phenolic hydroxyl groups in their molecules can be used alone or in combination of two or more.

[0118] Examples of polybenzo[a]azole precursor resins, polyimide precursors, p-hydroxystyrene / styrene copolymers, and (meth)acrylic resins include those described in Japanese Patent Application Publication Nos. 2018-169547, 2018-169627, International Publication Nos. 2010 / 134207, 2014 / 069202, 2020-101813, and 2018 / 232214. Each of the polybenzo[a]azole precursor resin, polyimide precursor, p-hydroxystyrene / styrene copolymer, and (meth)acrylic resin can be used individually or in combination of two or more.

[0119] When the coating resin composition comprises a resin that is photocurable and developable with a developer, the coating resin composition may optionally include a crosslinking agent. The crosslinking agent may be a component that is insoluble in the developer through a crosslinking reaction, or a component that cures through a crosslinking reaction and can form a coating layer. One type of crosslinking agent may be used alone, or two or more may be used in combination.

[0120] As a crosslinking agent, compounds having one or more, preferably two or more alkoxymethyl groups in their molecules can be used. Examples of such resins include amino resins containing two or more alkoxymethyl groups in their molecules and phenolic resins containing two or more alkoxymethyl groups in their molecules. From the perspective of superior photosensitivity, amino resins containing two or more alkoxymethyl groups in their molecules are preferred. Examples of amino resins containing two or more alkoxymethyl groups in their molecules include melamine resins and urea resins, with melamine resins being preferred.

[0121] Specific examples of melamine resins include: "MW-390", "MW-100LM", "MW-30HM", and "MX-750LM" manufactured by Sanwa Chemical Co., Ltd.; and the CYMEL series manufactured by Allnex Japan. Similarly, specific examples of urea resins include: "MX-270", "MX-279", and "MX-280" manufactured by Sanwa Chemical Co., Ltd.; and the CYMEL series manufactured by Allnex Japan. Melamine resins can be used alone or in combination of two or more types.

[0122] When the coating resin composition contains a photocurable resin, the coating resin composition may optionally contain a photopolymerization initiator. The photopolymerization initiator does not contain components equivalent to the thermosetting resin, cyclic carbonate compound, thermosetting accelerator, thermoplastic resin, photocurable resin, and crosslinking agent described above. As a photopolymerization initiator, a compound capable of accepting active light to generate free radicals or acids can be used. One photopolymerization initiator may be used alone, or two or more may be used in combination.

[0123] Examples of photopolymerization initiators include: oxime ester-based photopolymerization initiators, aminoketone-based photopolymerization initiators, acylphosphine-based photopolymerization initiators, α-hydroxyketone-based photopolymerization initiators, benzoin-based photopolymerization initiators, and benzyl ketal-based photopolymerization initiators. Additionally, photoacid generators can be used as photopolymerization initiators.

[0124] Examples of oxime ester-based photopolymerization initiators include: 2-(benzoyloxyimino)-1-[4-(phenylthio)phenyl]octane-1-one (OXE01), [1-[9-ethyl-6-(2-methylbenzoyl)carbazole-3-yl]ethimino]acetate (OXE02), and 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]acetone-1-(O-acetyl oxime), etc. Oxime ester-based photopolymerization initiators can be used alone or in combination of two or more.

[0125] Examples of α-amino ketone photopolymerization initiators include: 2-methyl-1-phenyl-2-morpholinopropane-1-one, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropane-1-one, 2-methyl-1-(4-hexylphenyl)-2-morpholinopropane-1-one, 2-ethyl-2-(dimethylamino)-1-(4-morpholinophenyl)butane-1-one, 2-benzyl-2-(dimethylamino)-1-(4-morpholinophenyl)butane-1-one, 2-(dimethylamino)-2-(4-methylphenylmethyl)-1-(4-morpholinophenyl)butane-1-one, and 2-methyl-1-(9,9-dibutylfluorene-2-yl)-2-morpholinopropane-1-one. Aminoketone-based photopolymerization initiators can be used alone or in combination of two or more.

[0126] Examples of acylphosphine-based photopolymerization initiators include bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, (2,4,6-trimethylbenzoyl)diphenylphosphine oxide, and polyoxyethylene glycerol ether tris[phenyl(2,4,6-trimethylbenzoyl)hypophosphite] (Polymeric TPO-L). Acylphosphine-based photopolymerization initiators can be used alone or in combination of two or more.

[0127] Examples of α-hydroxyketone photopolymerization initiators include: 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenylpropanone, 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methylpropanone, and 2-hydroxy-1-{4-[4-(2-hydroxy-2-methylpropanoyl)benzyl]phenyl}-2-methylpropane-1-one. One α-hydroxyketone photopolymerization initiator can be used alone, or two or more can be used in combination.

[0128] Examples of benzoin-based photopolymerization initiators include: benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzoin isobutyl ether. A single benzoin-based photopolymerization initiator can be used alone, or two or more can be used in combination.

[0129] Examples of benzyl ketal photopolymerization initiators include 2,2-dimethoxy-2-phenylacetophenone. Benzyl ketal photopolymerization initiators can be used alone or in combination of two or more.

[0130] Commercially available photopolymerization initiators can be used. Specific examples of commercially available photopolymerization initiators include: "Omnirad 907", "Omnirad 369", "Omnirad 379", "Omnirad 379EG", "Omnirad 819", and "Omnirad TPO" manufactured by IGM; "Irgacure TPO", "Irgacure OXE-01", and "Irgacure OXE-02" manufactured by BASF; and "N-1919" manufactured by ADEKA, etc.

[0131] Regarding photoacid generators used as photopolymerization initiators, compounds capable of generating acids upon irradiation with active light can be used. Examples of photoacid generators include halogen-containing compounds, diazonium ketone compounds, sulfone compounds, diazomethane compounds, and diazoquinone compounds. A single photoacid generator can be used alone, or two or more can be used in combination.

[0132] Examples of halogenated compounds that can be used as photoacid generators include, for example, hydrocarbon compounds containing alkyl halides and heterocyclic compounds containing alkyl halides. Suitable specific examples of halogenated compounds include: 2-[2-(furan-2-yl)vinyl]-4,6-bis(trichloromethyl)-triazine, 2-[2-(5-methylfuran-2-yl)vinyl]-4,6-bis(trichloromethyl)-triazine, 2-(methoxyphenyl)-4,6-bis(trichloromethyl)-triazine, and 2-[2-(4-methoxyphenyl)vinyl]-4,6-bis(trichloromethyl)-triazine. Triazine derivatives, such as 2-[2-(3,4-dimethoxyphenyl)vinyl]-4,6-bis(trichloromethyl)-triazine, 1,10-dibromo-n-decane, 1,1-bis(4-chlorophenyl)-2,2,2-trichloroethane, phenyl-bis(trichloromethyl)-triazine, 4-methoxyphenyl-bis(trichloromethyl)-triazine, styryl-bis(trichloromethyl)-triazine, and naphthyl-bis(trichloromethyl)-triazine, are examples of triazine derivatives. Specific examples of halogenated compounds include "TFE-triazine," "TME-triazine," "MP-triazine," "MOP-triazine," and "dimethoxytriazine" (halogenated compounds with a triazine skeleton that are photoacid generators) manufactured by Sanwa Chemical Co., Ltd. Halogenated compounds used as photoacid generators can be used alone or in combination of two or more.

[0133] Examples of diazonone compounds, sulfone compounds, and diazonoquinone compounds include those described in Japanese Patent Application Publication No. 2018-169627, International Publication No. 2010 / 134207, International Publication No. 2014 / 069202, Japanese Patent Application Publication No. 2020-101813, and International Publication No. 2018 / 232214. Each diazonone compound, sulfone compound, and diazonoquinone compound used as a photoacid generator may be used individually or in combination of two or more.

[0134] When the coating resin composition contains a photocurable resin, the coating resin composition may contain an epoxy resin as an optional component. The epoxy resin used as an optional component may be one described in the section on thermosetting resins.

[0135] When the coating resin composition contains a photocurable resin, the coating resin composition may optionally contain a photosensitizer. The photosensitizer does not contain components equivalent to the thermosetting resin, cyclic carbonate compound, thermosetting accelerator, thermoplastic resin, photocurable resin, crosslinking agent, and photopolymerization initiator described above. By using a photosensitizer, the photosensitivity of the photocurable resin can be improved. One photosensitizer may be used alone, or two or more may be used in combination.

[0136] Examples of photosensitizers include: benzophenones such as milchone, 4,4'-bis(diethylamino)benzophenone, and 4-morpholinobenzophenone; cyclic alkanes such as 2,5-bis(4'-diethylaminophenylmethylene)cyclopentane, 2,6-bis(4'-diethylaminophenylmethylene)cyclohexanone, and 2,6-bis(4'-diethylaminophenylmethylene)-4-methylcyclohexanone; and 4,4'-bis(dimethylamino)chalcone, 4,4'-bis(diethylamino)chalcone, etc. Chalcones such as (amino)chalcone; indanes such as p-dimethylaminocinnamyl indane and p-dimethylaminophenylmethylene indane; thiazoles such as 2-(p-dimethylaminophenyl biphenylene)-benzothiazole, 2-(p-dimethylaminophenyl vinylene)benzothiazole, and 2-(p-dimethylaminophenyl vinylene)isonaphthothiazole; acetones such as 1,3-bis(4'-dimethylaminophenylmethylene)acetone and 1,3-bis(4'-diethylaminophenylmethylene)acetone; 3 Coumarins such as 3'-carbonyl-bis(7-diethylaminocoumarin), 3-acetyl-7-dimethylaminocoumarin, 3-ethoxycarbonyl-7-dimethylaminocoumarin, 3-benzyloxycarbonyl-7-dimethylaminocoumarin, 3-methoxycarbonyl-7-diethylaminocoumarin, and 3-ethoxycarbonyl-7-diethylaminocoumarin; N-phenyl-N'-ethylethanolamine, N-phenyldiethanolamine, N-p-tolyldiethanolamine, N-phenylethanolamine, and dimethyl... Amines such as isoamyl aminobenzoate and isoamyl diethylaminobenzoate; heterocyclic compounds such as 2-mercaptobenzimidazole, 2-mercaptobenzothiazole, 2-(p-dimethylaminostyryl)benzo[a]azole, 2-(p-dimethylaminostyryl)benzo[a]thiazole, 2-(p-dimethylaminostyryl)naphtho(1,2-d)thiazole, 1-phenyl-5-mercaptotetrazole, and 1-p-hydroxyphenyl-5-mercaptotetrazole; and styrene compounds such as 2-(p-dimethylaminobenzoyl)styrene.

[0137] In addition to the components mentioned above, the coating resin composition may further contain other additives. Examples of such additives include: hot acid generators, inorganic fillers, organic fillers, surface treatment agents, organometallic compounds, colorants, polymerization inhibitors, homogenizers, thickeners, defoamers, ultraviolet absorbers, adhesion improvers, bonding agents, antioxidants, fluorescent whitening agents, surfactants, flame retardants, dispersants, stabilizers, and photopolymerization initiators. Other additives may be used individually or in combination of two or more.

[0138] The coating resin composition may contain a solvent as a volatile component. The solvents that may be included in the coating resin composition are the same as those that may be included in the core resin composition.

[0139] The coating resin composition can be manufactured, for example, by a manufacturing method that includes mixing the above-mentioned components. The components can be mixed partially or entirely simultaneously, or sequentially. During the mixing of the components, the temperature can be appropriately adjusted, thus allowing for temporary or continuous heating and / or cooling. Furthermore, stirring or agitation can be performed during the mixing of the components. Moreover, degassing can be carried out under low-pressure conditions such as vacuum.

[0140] [Resin Sheet] Using the aforementioned core resin composition and coating resin composition, a resin sheet for manufacturing optical waveguides can be manufactured. Specifically, the core resin composition can be used to manufacture the core resin sheet, and the coating resin composition can be used to manufacture the coating resin sheet. Based on this resin sheet, since the optical waveguide can be manufactured by lamination, the manufacturing of the optical waveguide can be simplified.

[0141] In one embodiment, the resin sheet includes: a core resin sheet comprising a support and a resin composition layer containing a core resin composition disposed on the support; and a coating resin sheet comprising a support and a resin composition layer containing a coating resin composition disposed on the support.

[0142] Regarding the thickness of the resin composition layer, whether it is a core resin sheet or a coating resin sheet, it is preferably 100 μm or less, more preferably 80 μm or less, and even more preferably 50 μm or less. There is no particular limitation on the lower limit of the thickness of the resin composition layer; for example, it can be set to 5 μm or more.

[0143] Examples of supports include films containing plastic materials, metal foils, and release paper, with one or more supports preferably selected from films containing plastic materials and metal foils.

[0144] When using a film containing plastic materials as a support, examples of thermoplastic resins include: polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), acrylics such as polycarbonate (PC) and polymethyl methacrylate (PMMA), cyclic polyolefins, cellulose triacetate (TAC), polyethersulfide (PES), polyetherketone, and polyimide. Preferably, one or more thermoplastic resins selected from polyethylene terephthalate and polyethylene naphthalate are used, and more preferably, inexpensive polyethylene terephthalate is preferred.

[0145] When using metal foil as a support, examples of metal foils include copper foil and aluminum foil, with copper foil being preferred. As copper foil, foils containing a single metal such as copper can be used, or foils containing alloys of copper and other metals (e.g., tin, chromium, silver, magnesium, nickel, zirconium, silicon, titanium, etc.) can be used.

[0146] The surface of the support that bonds to the resin composition layer can be treated with matte finish, corona treatment, or antistatic treatment. Furthermore, a support with a release layer on the surface bonded to the resin composition layer can be used as the support. Examples of release agents used in the release layer of a support with a release layer include, for example, one or more release agents selected from alkyd resins, polyolefin resins, urethane resins, and silicone resins. Commercially available release agents include, for example, "SK-1," "AL-5," and "AL-7" manufactured by LINTEC Corporation, which are alkyd resin-based release agents; and "NSP-4" manufactured by Fujimori Kogyo Co., Ltd. In addition, commercially available products that serve as supports with release layers include, for example, LINTEC's "SK-1", "AL-5", and "AL-7" PET films with release layers primarily composed of alkyd resin-based release agents; Toray Industries' "Lumirror T60"; Teijin's "Purex"; UNITIKA's "Unipeel"; and Fujimori Kogyo's "NSH".

[0147] There is no particular limitation on the thickness of the support, but it is preferably in the range of 5μm to 75μm, and more preferably in the range of 10μm to 60μm. It should be noted that when using a support with a release layer, the overall thickness of the support with the release layer is preferably within the above range.

[0148] In one embodiment, the resin sheet may further comprise other layers as needed. Examples of such other layers include, for instance, a protective film selected according to the support, disposed on the side of the resin composition layer that is not bonded to the support (i.e., the side opposite to the support). The thickness of the protective film is not particularly limited, and is, for example, 1 μm to 40 μm. By laminating the protective film, dust adhesion to the surface of the resin composition layer or damage to the surface of the resin composition layer can be suppressed.

[0149] Resin sheets can be manufactured, for example, by preparing a resin varnish in which a resin composition is dissolved in a solvent, applying the resin varnish onto a support using a die coater or similar machine, and further drying it to form a resin composition layer. Examples of solvents include organic solvents, as described above as components that may be included in the core resin composition. When manufacturing resin sheets, one type of organic solvent may be used alone, or two or more may be used in combination.

[0150] Drying can be carried out by known methods such as heating or blowing hot air. There are no particular limitations on the drying conditions; drying is generally carried out when the solvent content in the resin composition layer is 10% by mass or less, preferably 5% by mass or less. Although it varies depending on the boiling point of the solvent in the resin varnish, for example, when using a resin varnish containing 30% to 60% by mass of solvent, a resin composition layer can be formed by drying at 50°C to 150°C for 3 to 10 minutes.

[0151] The resin sheets can be stored by rolling them into rolls. If the resin sheet has a protective film, it can be used by peeling off the protective film.

[0152] [Optical waveguide] The aforementioned core resin composition and coating resin composition can be used to manufacture optical waveguides. Hereinafter, embodiments of this optical waveguide will be described with reference to the accompanying drawings.

[0153] According to the manufacturing method of the present invention, an optical waveguide 10 having a core layer 100 and a cladding layer 200 can be manufactured. The core layer 100 comprises a cured product of a core resin composition, preferably comprising only a cured product of a core resin composition. Furthermore, the cladding layer 200 comprises a cured product of a cladding resin composition, preferably comprising only a cured product of a cladding resin composition.

[0154] A core layer 100 is disposed within a cladding layer 200. Therefore, the core layer 100 is covered by the cladding layer 200. In one example, the entire circumferential surface of the core layer 100 is covered by the cladding layer 200. The core layer 100 and the cladding layer 200 are in direct contact without passing through other layers; therefore, an interface 100I can be formed between the core layer 100 and the cladding layer 200. Because the core layer 100 has a higher refractive index than the cladding layer 200, light (not shown) can be transmitted within the core layer 100 from one end (incident side) 100A to the other end (emission side) 100B.

[0155] The wavelength of light that can be transmitted through the optical waveguide 10 can be selected in various ways. For example, the preferred wavelength range of the transmitted light can be 840nm~860nm (e.g., 850nm), 1300nm~1320nm (e.g., 1310nm), 1540nm~1560nm (e.g., 1550nm), etc. Among them, the wavelength range of the light transmitted in the optical transmission path 10 is preferably 1300nm~1320nm.

[0156] The optical waveguide 10 can be a single-mode optical waveguide or a multi-mode optical waveguide, but is preferably a single-mode optical waveguide. Specifically, the optical waveguide 10 is preferably a single-mode optical waveguide for light within the preferred wavelength range described above. For example, the optical waveguide 10 is preferably a single-mode optical waveguide for light with a wavelength of 1310 nm.

[0157] In optical waveguide 10, from the viewpoint of realizing a single-mode optical waveguide for light with a wavelength of 1310 nm, the refractive index of the cured resin composition for the core is set to n. core Furthermore, the refractive index of the cured resin composition for coating is set as n. clad In the case of their difference (n) core -n clad The value is preferably 0.1 or less. The difference in refractive index (n) core -n clad There are no special restrictions on the lower limit of ), for example, it can be set to 0.001 or higher.

[0158] The width L of the core layer 100 is preferably set appropriately within the range where light transmission is possible. Specifically, the width L of the core layer 100 is preferably 0.5 μm or more, more preferably 1 μm or more, further preferably 2 μm or more, preferably 30 μm or less, more preferably 20 μm or less, further preferably 10 μm or less, or 5 μm or less. The width L of the core layer 100 corresponds to the linewidth of the core layer 100 when viewed from the thickness direction.

[0159] The spacing S of the core layer 100 is preferably set appropriately within a range suitable for optical transmission. Specifically, the spacing S of the core layer 100 is preferably 50 μm or more, more preferably 70 μm or more, further preferably 100 μm or more, preferably 1000 μm or less, more preferably 700 μm or less, and even more preferably 500 μm or less. The spacing S of the core layer 100 corresponds to the spacing (space) of the core layer when viewed from the thickness direction.

[0160] The thickness T of the core layer 100 is preferably set appropriately within the range where optical transmission is possible. Specifically, the thickness T of the core layer 100 is preferably 0.5 μm or more, more preferably 1 μm or more, further preferably 2 μm or more, preferably 50 μm or less, more preferably 30 μm or less, and further preferably 20 μm or less or 10 μm or less.

[0161] The thickness of the coating layer 200 is greater than the thickness T of the core layer 100. The specific thickness of the coating layer 200 is preferably 5 μm or more, more preferably 7 μm or more, even more preferably 10 μm or more, preferably 100 μm or less, more preferably 60 μm or less, even more preferably 40 μm or less or 30 μm or less.

[0162] Depending on the requirements, the optical waveguide 10 may have optional elements other than the core layer 100 and the cladding layer 200. Examples of optional elements include: a protective layer (not shown) protecting the core layer 100 and the cladding layer 200, a conductor layer (not shown) such as an electroplated layer, etc.

[0163] [Manufacturing methods for optical waveguides] The method for manufacturing the optical waveguide of the present invention is characterized in that it comprises, in sequence: In step (i), a metal-based wiring pattern is formed on the metal layer of a substrate (first substrate) with a metal layer. Step (ii) involves forming a first resin composition layer from a coating resin composition in a manner that contacts the metal layer and the wiring pattern described above, and then curing the first resin composition layer to form a first coating layer. Step (iii): Remove the substrate portion of the first substrate described above; Step (iv) involves removing the metal layer and the wiring pattern to form a recess corresponding to the wiring pattern. Step (v) involves forming a second resin composition layer from a core resin composition containing a thermosetting resin in a manner that contacts the aforementioned recess, and then curing the second resin composition layer to form a core base layer. Step (vi) involves removing a portion of the aforementioned core substrate layer to form a core layer; and Step (vii) involves forming a third resin composition layer from the coating resin composition in contact with the core layer and the first coating layer, and then curing the third resin composition layer to form a second coating layer.

[0164] As described above, in order to manufacture optical waveguides with fine patterns using thermosetting resins, the inventors investigated a technique for forming trenches in a coating material by laser processing and then forming a core within those trenches. However, when forming trenches in the coating material by laser processing, the following problems were identified: 1) Sometimes the cross-sectional shape of the trench is not rectangular, making it difficult to obtain a trench with the desired shape; 2) It is difficult to keep the trench depth constant based on laser processing, and the trench depth sometimes becomes uneven when viewed in the trench's extension direction; 3) Sometimes the bottom of the trench is rough, etc. Since the resulting core has a shape corresponding to the trench, the inventors have found that it is difficult to form a core with the desired cross-sectional shape or the desired thickness in the extension direction using the aforementioned laser-based trench forming technique. Furthermore, the inventors have found that the resulting core, using the aforementioned laser-based trench forming technique, results in a core with a rough boundary surface with the coating material.

[0165] In contrast, the method of the present invention, which involves forming a cladding by embedding a fine wiring pattern into a substrate, removing the substrate to expose the wiring pattern, removing the wiring pattern, and forming grooves (recesses) in the cladding, can form grooves in the cladding with a desired cross-sectional shape and a desired thickness in the extending direction. Furthermore, according to the method of the present invention, grooves that are smooth to the boundary surface of the cladding can also be achieved. Therefore, according to the method of the present invention, cores with fine linewidths can be uniformly formed at predetermined intervals with a desired shape / pattern, enabling optical waveguides with excellent dimensional stability. Hereinafter, each step in the manufacturing method of the optical waveguide of the present invention will be described in detail.

[0166] Figure 2 This is a schematic cross-sectional view illustrating step (i) of the method for manufacturing the optical waveguide of the present invention. Figure 2 As shown, the method for manufacturing an optical waveguide according to the present invention includes step (i): forming a metal-based wiring pattern 310 on the metal layer 302 of a substrate (first substrate) 300 with a metal layer.

[0167] In the substrate with a metal layer (first substrate) 300, there are no restrictions on the material of the substrate portion 301 of the first substrate. Examples of substrate portion 301 of the first substrate include: glass substrate; monocrystalline silicon substrate; metal substrate; ceramic substrate; silicon substrate having an inorganic film such as silicon oxide film. Among these, from the perspective of excellent flatness, the substrate portion 301 of the first substrate is preferably a glass substrate, a monocrystalline silicon substrate, or a silicon substrate having an inorganic film.

[0168] In the glass substrate of the substrate portion 301, which serves as the first substrate, the glass material constituting the glass substrate may include, for example, alkali-free glass, quartz glass, borosilicate glass, etc. One type of glass material may be used alone, or two or more types may be used in combination.

[0169] In the silicon substrate having an inorganic film in the substrate portion 301, which serves as the first substrate, the inorganic film includes a silicon oxide film. Furthermore, when the substrate portion 301 of the first substrate is a silicon substrate having an inorganic film, the first substrate 300 has an inorganic film including a silicon oxide film between the metal layer 302 and the silicon substrate.

[0170] The silicon substrate with an inorganic film in the substrate portion 301 of the first substrate may further include an inorganic film other than a silicon oxide film (hereinafter sometimes referred to as an "optional inorganic film"). Examples of optional inorganic films that may be included in this substrate include: silicon compound films containing silicon compounds such as silicon nitride, silicon oxide nitride, and silicon carbide (excluding silicon oxide films); ceramic films containing ceramic materials constituting ceramic substrates as described later; and metal films containing a single metal or alloy. When the substrate portion 301 of the first substrate is a silicon substrate with an inorganic film, and this inorganic film further includes an optional inorganic film, there are no particular limitations on the layer composition of the silicon oxide film and the optional inorganic film. Therefore, when the substrate portion 301 of the first substrate is a silicon substrate with an inorganic film, the first substrate 300 may have a layer composition of metal layer 302 / silicon oxide film / optional inorganic film / silicon substrate, or it may have a layer composition of metal layer 302 / optional inorganic film / silicon oxide film / silicon substrate.

[0171] In this case, the silicon substrate with an inorganic film in the substrate portion 301, which serves as the first substrate, preferably contains only a silicon oxide film between the metal layer 302 and the silicon substrate.

[0172] In the ceramic substrate of the substrate portion 301, which serves as the first substrate, the ceramic material constituting the ceramic substrate may include, for example, metal oxides, transition metal oxides, metal nitrides, and boride-based ceramics. Here, metal oxides and transition metal oxides may include composite oxides. Specific examples of ceramic materials include: metal oxides such as alumina, zinc oxide, magnesium oxide, and calcium oxide; composite oxides such as diamond, sapphire, cordierite, β-spodumene, forsterite, cermet, block talc, aluminum titanate, barium titanate, calcium titanate, strontium titanate, zinc titanate, mullite, spinel, calcium zirconate, strontium zirconate, barium zirconate titanate, bismuth titanate, and strontium bismuth titanate; metal nitrides such as aluminum nitride, boron nitride, and titanium nitride; and oxides... Transition metal oxides such as zirconium, yttrium oxide, nickel oxide, iron oxide, titanium oxide, tantalum oxide, tin oxide, vanadium oxide, cerium oxide, and chromium oxide; soft magnetic materials of ferrites such as Mg-Zn ferrite, Mn-Zn ferrite, Mn-Mg ferrite, Cu-Zn ferrite, Mg-Mn-Sr ferrite, Ni-Zn ferrite, Ni-Cu-Zn ferrite, Ni-Cu-Zn-Mg ferrite, and Ba ferrite; and boride-based ceramics. Ceramic materials can be used alone or in combination of two or more types.

[0173] In the substrate (first substrate) 300 with a metal layer, the metal layer 302 comprises one or more metals selected from gold, platinum, palladium, silver, copper, aluminum, cobalt, chromium, zinc, nickel, titanium, tungsten, iron, tin, and indium. The metal layer 302 can be a single metal layer or an alloy layer. Examples of alloy layers include layers formed from alloys of two or more metals selected from the above (e.g., nickel-chromium alloys, copper-nickel alloys, and copper-titanium alloys). From the viewpoint of versatility in metal layer formation, cost, and ease of patterning, single metal layers of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver, or copper, or alloy layers of nickel-chromium alloys, copper-nickel alloys, or copper-titanium alloys are preferred. More preferred are single metal layers of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver, or copper, or alloy layers of nickel-chromium alloys or copper-titanium alloys. Even more preferred are single metal layers of copper or alloy layers of copper-titanium alloys.

[0174] The metal layer 302 can be a single-layer structure, or a single metal layer containing different kinds of metals or alloys, or a multi-layer structure consisting of two or more alloy layers.

[0175] The metal used to form the wiring pattern 310 is the same as the metal that may be included in the metal layer 302. Preferably, the metal forming the wiring pattern 310 includes copper. The metal forming the wiring pattern 310 may contain only copper, or it may contain copper and optional metals other than copper. For example, the wiring pattern 310 may have an alloy layer containing copper and optional metals. Alternatively, for example, the wiring pattern 310 may have a layer containing copper and another layer containing optional metals. Examples of optional metals include gold, platinum, palladium, silver, aluminum, cobalt, chromium, zinc, nickel, titanium, tungsten, iron, tin, and indium. One optional metal may be used alone, or two or more may be used in combination.

[0176] The minimum line width / spacing (L / S) of the wiring pattern 310 can be determined based on the desired width L and spacing S of the core layer 100.

[0177] The thickness of the wiring pattern 310 can be determined based on the desired thickness T of the core layer 100. The thickness of the wiring pattern 310 may be the same as or less than the thickness T of the core layer 100. In a suitable embodiment, the thickness of the wiring pattern 310 is the same as the thickness T of the core layer 100.

[0178] In step (i), there are no particular limitations on the method for forming the metal-based wiring pattern 310. However, from the viewpoints of the versatility, cost, and ease of patterning of metal layer formation, electroplating is preferred as the method for forming the wiring pattern 310. For example, a metal-based wiring pattern 310 can be formed by sequentially including the following steps: In step (i-1), a mask layer is formed on the metal layer of a substrate (first substrate) with a metal layer in a manner that exposes the metal layer in accordance with a metal-based wiring pattern; In step (i-2), a metal-based wiring pattern is formed on the portion of the metal layer not covered by the mask layer by electroplating; and Step (i-3): Remove the mask layer.

[0179] Figure 3 This is a schematic cross-sectional view illustrating step (i-1) of one embodiment of the method for manufacturing the optical waveguide of the present invention. In step (i-1), the mask layer 400 may be formed, for example, using photoresist (not shown). Specifically, photoresist may be formed on the metal layer 302 of a substrate (first substrate) 300 with a metal layer, and the mask layer 400 may be formed by exposure and development using a photomask (not shown) corresponding to the desired pattern shape. As the photoresist, conventionally known photoresists capable of being developed with the desired conductor circuit pattern may be used, as well as film photoresists (dry film photoresists) and liquid photoresists. Examples of photoresist compositions include, for example, phenolic varnish resin compositions, acrylic resin compositions, etc. Commercially available photoresists may be used, such as "RY-5115" manufactured by Resonac Corporation and "ALPHO 20A263" manufactured by Nikko Materials Corporation.

[0180] Figure 4 This is a schematic cross-sectional view illustrating step (i-2) of one embodiment of the optical waveguide manufacturing method of the present invention. Figure 4 As shown, in step (i-2), after the mask layer 400 is formed, a metal-based wiring pattern 310 is formed on the metal layer 302 by electroplating. Specifically, in step (i-2), the metal-based wiring pattern 310 is formed on the portion 302S of the metal layer 302 that is not covered by the mask layer 400 by electroplating.

[0181] In electroplating, a metal-based wiring pattern 310 can be formed in an electroplating solution containing metal ions. For example, a metal layer 302 and an electrode (not shown) are placed in the electroplating solution, and a direct current is applied from a power source between the metal layer 302 and the electrode. In the portion 302S of the metal layer 302 not covered by the mask layer 400, metal ions are reduced, and metal is deposited, thus forming the metal-based wiring pattern 310.

[0182] Typically, an aqueous solution of a metal salt is used as the electroplating solution. There are no restrictions on the metal salt as long as it can form an electroplated layer. When copper is used as the metal, examples of copper salts include: copper sulfate pentahydrate, copper halides such as copper chloride, copper acetate, copper nitrate, copper tetrafluoroborate, alkyl sulfonate, aryl sulfonate, aminosulfonate, copper perchlorate, copper gluconate, etc., with copper sulfate being preferred. The concentration of the metal salt in the electroplating solution can be, for example, 50 g / L or more and 400 g / L or less. A saturation concentration is more preferable. Furthermore, the electroplating solution may contain: acids such as sulfuric acid, methanesulfonic acid, ethanesulfonic acid, propanesulfonic acid, hydrochloric acid, etc.; a halide ion supplier; a brightener; and additives such as surfactants.

[0183] In step (i-3), after forming the metal-based wiring pattern 310, the mask layer 400 is removed. There are no limitations on the method for removing the mask layer 400. For example, the mask layer 400 formed of photoresist can be removed by contacting a suitable stripping solution corresponding to the composition of the mask layer 400. In one example, the mask layer 400 can be removed using an alkaline stripping solution such as sodium hydroxide solution.

[0184] Regarding the manufacturing method of the optical waveguide of the present invention, after step (i) and before step (ii), as an optional step, step (ii') may be further included: planarizing the surface of the wiring pattern 310 by chemical mechanical polishing (CMP).

[0185] In chemical mechanical polishing (CMP), an abrasive slurry is used to planarize the surface of wiring pattern 310.

[0186] As the abrasive (abrasive particles) contained in the abrasive slurry in the form of a dispersed phase, any conventionally known abrasive can be used as long as it can flatten the wiring pattern 310. Examples of abrasive materials include, for example, inorganic particles such as silica, alumina, cerium oxide, titanium oxide, and chromium oxide; and organic particles such as diamond and hard resin particles. A single abrasive can be used, or two or more can be used in combination.

[0187] From the viewpoint of easily obtaining wiring patterns 310 with low surface roughness, the average particle size of the abrasive should be small. The average particle size of the abrasive can be set to less than 1 μm, less than 0.5 μm, less than 0.4 μm, less than 0.2 μm, etc. There is no particular limitation on the lower limit of this average particle size, for example, it can be set to more than 0.005 μm, more than 0.01 μm, etc.

[0188] There is no particular limitation on the concentration of abrasive in the grinding slurry, for example, it can be determined in the range of 0.01% by mass to 30% by mass (preferably 0.1% by mass to 25% by mass).

[0189] From the viewpoint of the dispersibility of the abrasive, the grinding slurry may also contain a dispersant. As a dispersant, conventionally known optional dispersants used in chemical mechanical grinding slurries can be used. Examples of such dispersants include: various surfactants such as ionic surfactants and nonionic surfactants; acids such as hydrochloric acid or nitric acid. Regarding the concentration of the dispersant in the grinding slurry, from the viewpoint of achieving good dispersibility of the abrasive, it can be appropriately determined in conjunction with the relationship to the concentration of the abrasive.

[0190] Provided it does not impair the effects of the invention, the grinding slurry may further contain other components, such as pH adjusters, thickeners, oxidants, corrosion inhibitors, etc. The concentration of these other components in the grinding slurry may be appropriately determined according to the intended purpose.

[0191] Water can be used as a dispersion medium for grinding slurries.

[0192] The grinding speed of the wiring pattern 310 surface can be adjusted by selecting / changing the hardness or average particle size of the abrasive, and the abrasive concentration in the abrasive slurry. For example, the higher the hardness of the abrasive, the higher the grinding speed of the wiring pattern 310 surface tends to be. Additionally, for example, the larger the average particle size of the abrasive, the higher the grinding speed of the wiring pattern 310 surface tends to be. Furthermore, for example, the higher the abrasive concentration in the abrasive slurry, the higher the grinding speed of the wiring pattern 310 surface tends to be.

[0193] In chemical mechanical polishing (CMP), the polishing pressure (the pressure exerted between the substrate carrier and the polishing pad) can be appropriately determined based on the composition of the wiring pattern 310 (the type and amount of metal formed), etc., to achieve the desired polishing speed. Furthermore, the rotational speeds of the substrate carrier and the polishing disc holding the polishing pad can also be appropriately determined based on the composition of the wiring pattern 310, etc., to achieve the desired polishing speed. For example, the higher the polishing pressure, the higher the polishing speed of the wiring pattern 310 tends to be. Similarly, the higher the rotational speed of the carrier or the polishing disc, the higher the polishing speed of the wiring pattern 310 tends to be.

[0194] Chemical mechanical polishing of wiring pattern 310 can be performed using commercially available chemical mechanical polishing equipment. Examples of commercially available chemical mechanical polishing equipment include the "LaboForce-100" polishing equipment manufactured by Struers Corporation.

[0195] Figure 5 and Figure 6 This is a schematic cross-sectional view illustrating step (ii) of the method for manufacturing the optical waveguide of the present invention. Figure 5 He Ru Figure 6As shown, the method for manufacturing the optical waveguide of the present invention includes step (ii): forming a first resin composition layer 210 by means of a coating resin composition in contact with the metal layer 302 and the wiring pattern 310, and curing the first resin composition layer 210 to form a first coating layer 211.

[0196] There are no particular limitations on the method for forming the first resin composition layer 210. For example, the first resin composition layer 210 can be formed by coating the metal layer 302 and the wiring pattern 310 with a coating resin composition. From the viewpoint of smooth coating, a varnish-like coating resin composition containing a solvent can be prepared and coated with the varnish-like coating resin composition.

[0197] Examples of coating methods include: gravure coating, micro-gravure coating, reverse coating, matching reverse coating, die coating, slot die coating, lip coating, comma coating, scraper coating, roller coating, doctor blade coating, curtain coating, cavity gravure coating, slot coating, spin coating, slit coating, spray coating, dip coating, hot melt coating, rod coating, glue applicator coating, air knife coating, curtain flow coating, offset printing, brush coating, and screen printing.

[0198] The coating resin composition can be applied in a single coat or in multiple coats. Furthermore, different coating methods can be combined when applying the coating resin composition. To avoid foreign matter contamination, the coating of the coating resin composition is preferably carried out in an environment with minimal foreign matter generation, such as a cleanroom.

[0199] After coating with the resin composition, the first resin composition layer 210 can be dried as needed. Drying can be performed using a drying device such as a hot air furnace or a far-infrared furnace. The drying conditions are preferably set appropriately according to the composition of the coating resin composition. For example, the drying temperature is preferably 50°C or higher, more preferably 70°C or higher, even more preferably 80°C or higher, preferably 150°C or lower, more preferably 130°C or lower, and even more preferably 120°C or lower. In addition, the drying time is preferably 30 seconds or higher, more preferably 60 seconds or higher, even more preferably 120 seconds or higher, preferably 60 minutes or lower, more preferably 20 minutes or lower, and even more preferably 5 minutes or lower.

[0200] The first resin composition layer 210 can be formed, for example, using the aforementioned coating resin sheet. Specifically, the first resin composition layer 210 can be formed on the metal layer 302 and wiring pattern 310 by laminating the resin composition layer of the coating resin sheet in contact with the metal layer 302 and wiring pattern 310. The lamination of the coating resin sheet with the metal layer 302 and wiring pattern 310 can be performed, for example, by heating and pressing the coating resin sheet onto the metal layer 302 and wiring pattern 310 from the support side. Examples of components for heating and pressing the coating resin sheet onto the metal layer 302 and wiring pattern 310 (hereinafter also referred to as "heat-pressing component") include, for example, a heated metal plate (SUS end plate, etc.) or a metal roller (SUS roller). It should be noted that the heat-pressing component can be pressed directly onto the resin sheet, or it can be pressed through an elastic material such as heat-resistant rubber, so that the coating resin sheet fully follows the irregularities formed by the metal layer 302 and wiring pattern 310. In addition, before the resin sheet is laminated, preheating of the resin sheet and the substrate (first substrate) 300 with the metal layer may be performed as needed.

[0201] The lamination of the coating resin sheets can be carried out by vacuum lamination. In vacuum lamination, the heating and pressing temperature is preferably in the range of 60°C to 160°C, more preferably in the range of 80°C to 140°C. Furthermore, the heating and pressing pressure is preferably in the range of 0.098 MPa to 1.77 MPa, more preferably in the range of 0.29 MPa to 1.47 MPa. Furthermore, the heating and pressing time is preferably in the range of 20 seconds to 400 seconds, more preferably in the range of 30 seconds to 300 seconds. The lamination of the coating resin sheets can preferably be carried out under reduced pressure conditions of 26.7 hPa or less. Lamination by vacuum lamination can be performed intermittently or continuously using rollers.

[0202] Lamination can be performed using commercially available vacuum laminators. Examples of commercially available vacuum laminators include: vacuum pressure laminators manufactured by Meiki Seisakusho Co., Ltd., vacuum applicators manufactured by Nikko Materials Co., Ltd., and intermittent vacuum pressure laminators.

[0203] When the first resin composition layer 210 is formed using a coating resin sheet with a support, the support is peeled off at an appropriate time.

[0204] In step (ii), the first resin composition layer 210 formed on the metal layer 302 and the wiring pattern 310 contains a coating resin composition, preferably only contains a coating resin composition.

[0205] Furthermore, the curing of the first resin composition layer 210 can be appropriately determined according to the composition of the coating resin composition. For example, if the coating resin composition contains a thermosetting resin, the first resin composition layer 210 can be cured by heat treatment to form the first coating layer 211. Alternatively, if the coating resin composition contains a photocurable resin, the first resin composition layer 210 can be cured by exposure treatment to form the first coating layer 211. Furthermore, if the coating resin composition contains both a thermosetting resin and a photocurable resin, the first coating layer 211 can be formed by combining heat treatment and exposure treatment to cure the first resin composition layer 210.

[0206] The heat treatment conditions of the coating resin composition can be selected according to the type and amount of thermosetting resin in the coating resin composition. For example, the curing temperature is preferably 120°C to 240°C, more preferably 140°C to 220°C. In addition, the curing time is preferably 5 minutes to 120 minutes, more preferably 10 minutes to 100 minutes, and even more preferably 15 minutes to 100 minutes.

[0207] In the heat treatment of the coating resin composition, preheating of the first resin composition layer 210 may be included at a temperature below the curing temperature. As an example, the first resin composition layer 210 may be preheated, for example, at a temperature of 50°C to 150°C, preferably 60°C to 140°C, more preferably 70°C to 130°C, for at least 5 minutes, preferably 5 minutes to 150 minutes, more preferably 15 minutes to 120 minutes, and even more preferably 15 minutes to 100 minutes, before heat curing. Preheating may be performed, for example, after the formation of the first resin composition layer 210.

[0208] The exposure conditions for the coating resin composition can be selected based on the type and amount of photocurable resin in the composition. For example, an exposure dose of 10 mJ / cm is preferred. 2 The above, more preferably 50 mJ / cm 2 The above is further optimized to 200 mJ / cm. 2 The above, preferably 10,000 mJ / cm 2 Below, 8,000 mJ / cm is more preferred. 2 The following is a further preferred value: 4,000 mJ / cm². 2 Below, 3,000 mJ / cm 2 Below, 2,000 mJ / cm 2 Below or 1,000 mJ / cm 2 the following.

[0209] When the first coating layer 211 is formed using a coating resin sheet with a support, in step (ii), a support (not shown) may be present on the first coating layer 211. When the support is present on the first coating layer 211, exposure can be performed through the support, or exposure can be performed after the support is removed.

[0210] like Figure 6 As shown, a first coating layer 211 can be formed by curing the first resin composition layer 210 in step (ii). This first coating layer 211 (i.e., the cured first resin composition layer 210) forms a portion of the coating layer 200.

[0211] In the method for manufacturing the optical waveguide of the present invention, step (ii) preferably includes step (ii-1) before the curing of the first resin composition layer 210: a support (second substrate) (not shown) is bonded to the first resin composition layer 210 on the side of the first resin composition layer 210 opposite to the substrate (first substrate) with the metal layer. Based on this support (second substrate), the substrate portion 301 of the first substrate can be easily removed in step (iii).

[0212] There are no restrictions on the material of the support (second substrate), and examples include: glass substrate; single-crystal silicon substrate; metal substrate; silicon substrate with inorganic film; ceramic substrate, etc. Among these, from the perspective of excellent flatness, the support (second substrate) is preferably a glass substrate, a single-crystal silicon substrate, or a silicon substrate with inorganic film.

[0213] In the glass substrate, which serves as the second substrate, examples of glass materials constituting the glass substrate include alkali-free glass, quartz glass, and borosilicate glass. A single glass material may be used, or two or more may be used in combination.

[0214] In the silicon substrate having an inorganic film as the second substrate, the inorganic film includes a silicon oxide film. Furthermore, when the second substrate is a silicon substrate having an inorganic film, the second substrate has an inorganic film including a silicon oxide film on the surface bonded to the first resin composition layer 210.

[0215] The silicon substrate with an inorganic film, serving as the second substrate, may further include an optional inorganic film. The optional inorganic film that may be included in this substrate is the same as the optional inorganic film that may be included in the substrate portion 301 of the first substrate. When the second substrate is a silicon substrate with an inorganic film, and this inorganic film further includes an optional inorganic film, there are no particular limitations on the layer configuration of the silicon oxide film and the optional inorganic film. Therefore, when the second substrate is a silicon substrate with an inorganic film, the second substrate may have a layer configuration of silicon oxide film / optional inorganic film / silicon substrate, or it may have a layer configuration of optional inorganic film / silicon oxide film / silicon substrate.

[0216] The silicon substrate with an inorganic film, which serves as the second substrate, preferably contains only a silicon oxide film on the surface that is bonded to the first resin composition layer 210.

[0217] There are no particular limitations on the bonding method between the support (second substrate) and the first resin composition layer 210. For example, step (ii-1) can be performed by laminating the support (second substrate) in such a way that the surface of the first resin composition layer 210 is in contact with the side opposite to the metal-layered substrate (first substrate). The lamination of the support (second substrate) can be performed in the same manner as the lamination of the coating resin sheet described above.

[0218] Figure 7 This is a schematic cross-sectional view illustrating step (iii) of the method for manufacturing the optical waveguide of the present invention. Figure 7 As shown, the method for manufacturing an optical waveguide according to the present invention includes step (iii): removing the substrate portion 301 of the first substrate.

[0219] In step (iii), there are no particular limitations on the method for removing the substrate portion 301 of the first substrate, but it is preferable to remove it by peeling off the substrate portion 301 of the first substrate and / or grinding the substrate portion 301 of the first substrate. Therefore, step (iii) preferably includes step (iii-1): peeling off the substrate portion 301 of the first substrate; and / or step (iii-2): grinding the substrate portion 301 of the first substrate.

[0220] In process (iii-1), for example, the substrate portion 301 of the first substrate can be peeled off by stretching the substrate portion 301 of the first substrate relative to the metal layer 302.

[0221] In step (iii-2), the grinding conditions for the substrate portion 301 of the first substrate can include: chemical mechanical polishing (CMP) methods based on a chemical mechanical polishing (CMP) apparatus; belt grinding, polishing grinding, ceramic grinding, grinding based on a surface grinding disc, surface grinding based on a grinding stone rotation, and other mechanical polishing methods. It should be noted that, in this specification, unless otherwise stated, the term "grinding" can include grinding. Furthermore, various abrasive grains of different grit sizes can be used depending on the state of the target grinding surface. Additionally, the degree of grinding of the substrate portion 301 of the first substrate can be, for example, completed at the point when the surface of the metal layer 302 is exposed.

[0222] Figure 8 This is a schematic cross-sectional view illustrating step (iv) of the method for manufacturing the optical waveguide of the present invention. Figure 8As shown, the manufacturing method of the optical waveguide of the present invention includes step (iv): removing the metal layer 302 and the wiring pattern 310 to form a recess 500 corresponding to the wiring pattern 310.

[0223] In step (iv), there are no particular limitations on the method for removing the metal layer 302 and the wiring pattern 310. For example, the metal layer 302 and the wiring pattern 310 can be removed by dry processing using gas, plasma, various light beams, etc., or by wet processing using an etching solution. It is preferable to remove the metal layer 302 and the wiring pattern 310 by wet processing using an etching solution. Therefore, step (iv) preferably includes step (iv-1): removing the metal layer 302 and the wiring pattern 310 by wet processing using an etching solution to form a recess 500 corresponding to the wiring pattern 310.

[0224] Examples of etching solutions include: etching solutions with hydrogen peroxide as the main component (hydrogen peroxide-based etching solutions), acidic etching solutions, and alkaline etching solutions, with hydrogen peroxide-based etching solutions being preferred.

[0225] As a hydrogen peroxide-based etching solution, an etching solution containing hydrogen peroxide and an inorganic acid is preferred. Examples of inorganic acids include sulfuric acid, nitric acid, and phosphoric acid. Commercially available hydrogen peroxide-based etching solutions include, for example, the SAC series of etching solutions manufactured by JCU. Additionally, as an acidic etching solution, examples include ferric chloride aqueous solution, aqueous solution containing sodium persulfate and sulfuric acid, and etching solutions with nitric acid and sulfuric acid as the main components. Commercially available acidic etching solutions include, for example, "NH-1865" manufactured by MEC and "Melstrip N-950" manufactured by Meltex. Furthermore, commercially available alkaline etching solutions include, for example, "CF-6000" manufactured by MEC and "E-Process-WL" manufactured by Meltex.

[0226] In step (iv-1), the removal of the metal layer 302 and the wiring pattern 310 can be performed, for example, by immersing the metal layer 302 and the wiring pattern 310 in an etching solution, or by spraying the etching solution onto the metal layer 302 and the wiring pattern 310. In one example, the temperature of the etching solution is preferably 5°C or higher, more preferably 10°C or higher, even more preferably 15°C or higher, preferably 60°C or lower, more preferably 50°C or lower, and even more preferably 40°C or lower.

[0227] Figure 9 and Figure 10 This is a schematic cross-sectional view illustrating step (v) of the method for manufacturing the optical waveguide of the present invention. Figure 9 He Ru Figure 10As shown, the method for manufacturing the optical waveguide of the present invention includes step (v): forming a second resin composition layer 110 from a core resin composition comprising a thermosetting resin in contact with the recess 500, and curing the second resin composition layer 110 to form a core substrate layer 111. The second resin composition layer 110 is formed in such a way that it contacts the recess 500 and covers the surface of the first covering layer 211 that contacts the metal layer 302.

[0228] There are no particular limitations on the method for forming the second resin composition layer 110. For example, the second resin composition layer 110 can be formed by coating the core resin composition onto the recess 500. From the viewpoint of smoothly performing the coating, a varnish-like core resin composition containing a solvent can be prepared and coated. The coating of the core resin composition can be performed using the same method as the coating of the coating resin composition. In addition, after coating the core resin composition, the second resin composition layer 110 can be dried as needed. The drying of the second resin composition layer 110 can be performed using the same method and conditions as the drying of the first resin composition layer 210.

[0229] The second resin composition layer 110 can be formed, for example, using the core resin sheet described above. Specifically, the second resin composition layer 110 can be formed by laminating the resin composition layers of the core resin sheet in contact with the recess 500. The lamination of the core resin sheet can be performed using the same methods and conditions as the lamination of the covering resin sheet. When the second resin composition layer 110 is formed using a core resin sheet with a support, the support is peeled off at an appropriate time.

[0230] In step (v), the second resin composition layer 110, which is formed in a manner that is in integral contact with the first resin composition layer 210, contains a core resin composition, preferably only contains a core resin composition.

[0231] Furthermore, the curing of the second resin composition layer 110 can be appropriately determined according to the composition of the core resin composition. In the manufacturing method of the optical waveguide of the present invention, since the core resin composition contains a thermosetting resin, the second resin composition layer 110 is cured by heat treatment to form a core substrate layer 111. Alternatively, an exposure treatment may be performed as needed to form the core substrate layer 111. The heat treatment conditions (including exposure treatment as needed) for forming the core substrate layer 111 can be the same as those for the heat treatment (and exposure treatment) of the coating resin composition.

[0232] like Figure 10 As shown, a core substrate layer 111 can be formed by curing the second resin composition layer 110 in step (v). The core substrate layer 111 (i.e., the cured second resin composition layer 110) includes a core layer 100.

[0233] Figure 11 This is a schematic cross-sectional view illustrating step (vi) of the method for manufacturing the optical waveguide of the present invention. For example... Figure 11 As shown, the method for manufacturing the optical waveguide of the present invention includes step (vi): removing a portion of the aforementioned core substrate layer 111 to form a core layer 100.

[0234] In step (vi), there are no particular limitations on the method for removing a portion of the core substrate layer 111. Examples include laser irradiation, etching, mechanical drilling, and chemical mechanical polishing (CMP). From the viewpoint of easily controlling the thickness T of the core layer 100 and easily adjusting the flatness of the core layer, it is preferable to polish a portion of the core substrate layer 111 using chemical mechanical polishing (CMP). Therefore, step (vi) preferably includes step (vi-1): polishing a portion of the core substrate layer 111 using chemical mechanical polishing (CMP) to form the core layer 100. The polishing conditions for the core substrate layer 111 can, for example, be the same as those in step (ii').

[0235] In step (vi), the degree of removal (preferably chemical mechanical polishing) of a portion of the core substrate 111 can be determined based on the desired thickness T of the core layer 100. In a suitable embodiment, since the thickness of the wiring pattern 310 is the same as the thickness T of the core layer 100, and the depth of the recess 500 is the same as the thickness of the wiring pattern 310, the core layer 100 can be formed by ending the removal (preferably chemical mechanical polishing) of a portion of the core substrate 111 at the point when the surface of the first covering layer 201 is exposed.

[0236] Figure 12 and Figure 13 This is a schematic cross-sectional view illustrating step (vii) of the method for manufacturing the optical waveguide of the present invention. For example... Figure 12 He Ru Figure 13 As shown, the method for manufacturing the optical waveguide of the present invention includes step (vii): forming a third resin composition layer 220 from a coating resin composition in contact with the core layer 100 and the first coating layer 211, and curing the third resin composition layer 220 to form a second coating layer 221. The third resin composition layer 220 is formed in such a way that it covers the entire peripheral surface of the core layer 100 that is not in contact with the first coating layer 211. Therefore, the third resin composition layer 220 is formed in such a way that it covers the core layer 100, and is also formed in contact with the first coating layer 211.

[0237] There are no particular limitations on the method for forming the third resin composition layer 220. For example, the third resin composition layer 220 can be formed by coating the core layer 100 and the first coating layer 211 with a photosensitive resin composition for coating. The coating of the coating resin composition used to form the third resin composition layer 220 can be performed in the same manner as the coating of the coating resin composition used to form the first resin composition layer 210. In addition, after coating with the coating resin composition, the third resin composition layer 220 can be dried as needed. The drying of the third resin composition layer 220 can be performed using the same method and conditions as the drying of the first resin composition layer 210.

[0238] The formation of the third resin composition layer 220 can be performed, for example, using the aforementioned coating resin sheet. Specifically, the third resin composition layer 220 can be formed by laminating the resin composition layers of the coating resin sheet in contact with the core layer 100 and the first coating layer 211. The lamination of the coating resin sheet for forming the third resin composition layer 220 can employ the same methods and conditions as the lamination of the coating resin sheet for forming the first resin composition layer 210. When the third resin composition layer 220 is formed using a coating resin sheet with a support, the support is peeled off at an appropriate time.

[0239] In step (vii), the third resin composition layer 220, formed in contact with the core layer 100 and the first coating layer 211, contains a coating resin composition, preferably only contains a coating resin composition.

[0240] Furthermore, the curing of the third resin composition layer 220 can be appropriately determined based on the composition of the coating resin composition. For example, the curing of the third resin composition layer 220 can be carried out in the same manner as the curing of the first resin composition layer 210.

[0241] like Figure 13 As shown, a second coating layer 221 can be formed by curing the third resin composition layer 220 in step (vii). This second coating layer 221 (i.e., the cured third resin composition layer 220) forms a portion of the coating layer 200. Moreover, the coating layer 200 is formed by the first coating layer 211 and the second coating layer 221. Therefore, an optical waveguide 10 having a coating layer 200 including the first coating layer 211 and the second coating layer 221, and a core layer 100 disposed within the coating layer 200, can be obtained.

[0242] In the case where the optical waveguide manufacturing method includes step (ii-1), the optical waveguide manufacturing method of the present invention may further include step (viii) after step (vii): removing the aforementioned support (second substrate). There are no particular limitations on the method for removing the support (second substrate). For example, the removal of the support (second substrate) may be performed in the same manner as the removal of the substrate portion 301 of the first substrate in step (iii).

[0243] As described above, the optical waveguide 10 may further include a conductor layer such as an electroplated layer. Therefore, in the manufacturing method of the optical waveguide of the present invention, after step (vii) (or step (viii)), a step (ix) may be further included: forming a conductor layer in contact with the cladding layer 200. There are no particular limitations on the location where the conductor layer is formed, as long as the conductor layer is in contact with the cladding layer 200. When the optical waveguide 10 includes a conductor layer, the conductor layer is preferably formed by electroplating. In addition, before forming the conductor layer by electroplating, the surface of the cladding layer 200 that is in contact with the conductor layer (hereinafter, sometimes referred to as "surface 200S") may be roughened.

[0244] There are no particular limitations on the steps or conditions of the roughening treatment. For example, the surface 200S can be roughened by sequentially performing a swelling treatment based on a swelling solution, a roughening treatment based on an oxidant, and a neutralization treatment based on a neutralizing solution.

[0245] Examples of swelling solutions used for roughening treatment include alkaline solutions and surfactant solutions, with alkaline solutions being preferred. Sodium hydroxide solutions and potassium hydroxide solutions are more preferred as alkaline solutions. Commercially available swelling solutions include, for example, "Swelling Dip Securiganth P" and "Swelling Dip Securiganth SBU" manufactured by Atotech Japan. There are no particular limitations on the swelling treatment based on the swelling solution; for example, it can be performed by immersing the surface 200S in a swelling solution at 30°C to 90°C for 1 to 20 minutes. From the viewpoint of suppressing the swelling of the resin on the surface 200S to a suitable level, it is preferable to immerse the surface of the coating layer 200 in a swelling solution at 40°C to 80°C for 5 to 15 minutes.

[0246] Examples of oxidants used for roughening treatment include alkaline permanganate solutions obtained by dissolving potassium permanganate or sodium permanganate in an aqueous solution of sodium hydroxide. For roughening treatment using alkaline permanganate solutions or similar oxidants, it is preferable to immerse the insulating layer in an oxidant solution heated to 60°C to 100°C for 10 to 30 minutes. Furthermore, the concentration of permanganate in the alkaline permanganate solution is preferably 5% to 10% by mass. Examples of commercially available oxidants include alkaline permanganate solutions such as "Concentrate Compact CP" and "Dosing Solution Securiganth P" manufactured by Atotech Japan.

[0247] As the neutralizing solution for the roughening treatment, an acidic aqueous solution is preferred. Commercially available products include, for example, "Reduction Solution Securiganth P" manufactured by Atotech Japan. The treatment based on the neutralizing solution can be performed by immersing the surface that has undergone oxidant-based roughening treatment in a neutralizing solution at 30°C to 80°C for 5 to 30 minutes. From an operability perspective, immersing the object that has undergone oxidant-based roughening treatment in a neutralizing solution at 40°C to 70°C for 5 to 20 minutes is preferred.

[0248] The arithmetic mean roughness Ra of the surface 200S is preferably less than 500 nm, more preferably less than 400 nm, even more preferably less than 200 nm, and even more preferably less than 200 nm. There is no particular limitation on the lower limit, for example, it can be set to more than 1 nm, more than 2 nm, etc.

[0249] After the roughening treatment is completed, a conductor layer is formed on the roughened surface 200S. Specifically, the surface 200S can be electroplated using methods such as semi-additive or fully additive methods to form a conductor layer with the desired wiring pattern. From the viewpoint of ease of manufacturing, it is preferable to form the conductor layer using the semi-additive method. An example of forming a conductor layer using the semi-additive method is shown below.

[0250] An electroplating seed layer is formed on surface 200S by electroless electroplating. Next, a mask pattern is formed on the formed electroplating seed layer, corresponding to the desired wiring pattern, exposing a portion of the electroplating seed layer. After forming a metal layer on the exposed electroplating seed layer by electrolytic electroplating, the mask pattern is removed. Then, the unwanted electroplating seed layer is removed by etching or the like, forming a conductor layer with the desired wiring pattern.

[0251] As described above, the optical waveguide 10 may include a protective layer comprising a protective core layer 100 and a cladding layer 200. Therefore, the method for manufacturing the optical waveguide of the present invention may further include a step of forming the protective layer. Additionally, the method for manufacturing the optical waveguide of the present invention may include a step of cutting the manufactured optical waveguide 10.

[0252] The manufacturing method of the optical waveguide 10 may further include optional steps in combination with the above-mentioned steps.

[0253] The method for manufacturing the optical waveguide of the present invention can repeatedly perform the above-described steps. For example, the above-described steps can be repeatedly performed to manufacture an optical waveguide with a multilayer structure having a core layer and a cladding layer alternately in the thickness direction.

[0254] [Optoelectronic hybrid substrate and its manufacturing method] One embodiment of the present invention relates to an optoelectronic hybrid substrate comprising the aforementioned optical waveguide. Typically, an optoelectronic hybrid substrate comprises an optical waveguide and a circuit board. The circuit board may include electronic components and wiring connected to those electronic components. Examples of electronic components include passive components such as capacitors, inductors, and resistors; and active components such as semiconductor chips. Furthermore, the optical waveguide and the wiring of the circuit board may be connected via photoelectric conversion elements. These photoelectric conversion elements may combine an electric light-emitting element (e.g., a surface-emitting diode) that converts electricity into light and a light-receiving element (e.g., a photodiode) that converts light into electricity. Moreover, the optoelectronic hybrid substrate may also include optical elements such as mirrors for adjusting the optical path.

[0255] As a preferred example of a hybrid optoelectronic substrate, one could include a substrate having a chip on which an optoelectronic integrated circuit is formed on a silicon wafer. This chip is expected to be used in the early practical applications of silicon photonics, for example, in mounting within semiconductor packages. The hybrid optoelectronic substrate having this chip may include, for example, a circuit board, a chip mounted on the circuit board, and an optical waveguide. The optical waveguide can be used to connect wiring on the circuit board to the chip, or to connect multiple chips.

[0256] In chips manufactured using silicon photonics, wavelengths of light, typically 1310 nm and 1550 nm, are commonly used, with 1310 nm being the most prevalent (Sho Yoshida, Daisuke Suganuma, and Takaaki Ishifu, "Fabrication and Low-Loss of Single-Mode Polymer Waveguides Based on the Mosquito Method," 28th Japan Electronics and Information Technology Society Spring Conference, 2014). Therefore, optical waveguides are preferably capable of transmitting light at or near wavelengths of 1310 nm and 1550 nm, for example, preferably light with wavelengths between 1300 nm and 1320 nm. The optical waveguides described in the above embodiments can transmit light of these wavelengths.

[0257] Generally, compared to multimode, single-mode waveguides offer faster transmission speeds. Therefore, from the viewpoint of high-speed transmission, single-mode waveguides are preferred for use in optoelectronic hybrid circuits. In single-mode waveguides, a small core layer width is preferred. For example, a core layer with a width of 10 μm or less, or 5 μm or less, is preferred. Furthermore, waveguides with such a small core layer are also preferred from the viewpoint of increasing the design freedom of semiconductor packages when applied to them. The core layer width can be reduced as described above in the waveguides according to the embodiments described above.

[0258] On the other hand, when multiple optoelectronic hybrid substrates are connected, these substrates can be connected via optical fibers. For example, multiple optoelectronic hybrid substrates can be mounted on a rack and connected to each other by optical fibers. The optical fibers connecting these substrates are predominantly multimode. Therefore, from the viewpoint of being able to connect to these optical fibers, multimode optical waveguides can be used as the optical waveguides mounted on the optoelectronic hybrid substrates.

[0259] From the viewpoint of improving versatility, it is desirable that optical waveguides can be applied to either single-mode or multi-mode applications. Furthermore, it is desirable to reduce the minimum width of the core layer of these optical waveguides and increase the degree of freedom in the linewidth of the core layer. According to the optical waveguides of the embodiments described above, by using the core resin composition of the present invention in the core, a fine core can be formed, thus reducing the minimum width of the core layer. In addition, optical waveguides of either single-mode or multi-mode can also be obtained according to the optical waveguides of the embodiments described above. Therefore, the optical waveguides of the embodiments described above can be applied to a wide range of applications. Moreover, given their wide applicability while suppressing light transmission loss, the optical waveguides of the embodiments described above are suitable for application in optoelectronic hybrid substrates.

[0260] Since the optoelectronic hybrid substrate has the aforementioned optical waveguide, the manufacturing method of the optoelectronic hybrid substrate includes the same method as the manufacturing method of the optical waveguide.

[0261] [Semiconductor Devices] One embodiment of the present invention relates to a semiconductor device comprising the aforementioned optoelectronic hybrid substrate. Examples of such semiconductor devices include various semiconductor devices for use in electronic products (e.g., computers, mobile phones, smartphones, tablet devices, wearable devices, digital cameras, medical devices, and televisions) and vehicles (e.g., motorcycles, automobiles, electric trains, ships, and airplanes). Example

[0262] The following examples illustrate the invention in detail. However, the invention is not limited to these examples. In the following description, unless otherwise specified, "parts" and "%" refer to "parts by mass" and "% by mass," respectively. Furthermore, unless otherwise specified, the temperature and pressure conditions are room temperature (23°C) and atmospheric pressure (1 atm).

[0263] <Manufacturing Example 1: Manufacturing of Coating Resin Composition and Resin Sheet 1> 23 parts of phenoxy resin (YX7200B35, manufactured by Mitsubishi Chemical Corporation, a phenoxy resin having a biphenyl structure and a structure derived from bisphenol TMC, in a methyl ethyl ketone solution with 35% non-volatile components), 20 parts of epoxy resin (YX7760, manufactured by Mitsubishi Chemical Corporation, a bisphenol AF type epoxy resin, with an epoxy equivalent of 245 g / eq.), and 1.4 parts of a cyclic carbonate compound (5,5-dimethyl-4-(propane-2-yl)-1,3-dialkyl-2-one, manufactured by JNC Corporation) were mixed, and the resulting mixture was heated to dissolve, obtaining a dissolved composition. 0.36 parts of a curing accelerator (TBP-DA, tetrabutylphosphonium decanoate, manufactured by Hokko Chemical Industry Co., Ltd.) were mixed into the obtained dissolved composition to obtain resin varnish 1.

[0264] A polyethylene terephthalate film ("NSH" manufactured by Fujimori Kogyo Co., Ltd., 50 μm thick) treated with a non-silicone release agent was prepared as a support. Using a die coater, resin varnish 1 was uniformly applied to the release layer of the support to achieve a dried resin composition layer thickness of 50 μm. The resin varnish 1 was then dried at 100°C for 5 minutes to produce a resin sheet 1 comprising the support and a coating resin composition layer (50 μm thick).

[0265] <Manufacturing Example 2: Manufacturing of Core Resin Composition and Resin Sheet 2> 23 parts of phenoxy resin (YX7200B35, manufactured by Mitsubishi Chemical Corporation), 18 parts of epoxy resin (YX7760, manufactured by Mitsubishi Chemical Corporation), and 1.4 parts of cyclic carbonate compound (5,5-dimethyl-4-(propane-2-yl)-1,3-dialkyl-2-one, manufactured by JNC Corporation) were mixed, and the resulting mixture was heated to dissolve, thus obtaining a dissolved composition. 0.36 parts of a curing accelerator (TBP-DA, tetrabutylphosphonium decanoate, manufactured by Hokko Chemical Industry Co., Ltd.) were then mixed into the dissolved composition to obtain resin varnish 2.

[0266] A polyethylene terephthalate film ("NSH" manufactured by Fujimori Kogyo Co., Ltd., 50 μm thick) treated with a non-silicone release agent was prepared as a support. Using a die coater, resin varnish 2 was evenly applied to the release layer of the support to achieve a dried resin composition layer thickness of 50 μm. The resin varnish was then dried at 100°C for 5 minutes to produce a resin sheet 2 comprising the support and a core resin composition layer (50 μm thick).

[0267] <Example 1: Fabrication of an Optical Waveguide> (1) Preparation of the first substrate An 8-inch silicon wafer substrate (725 μm thick) with a seed layer (metal layer) of Ti / Cu=50 / 200 nm was prepared as the first substrate.

[0268] (2) Formation of wiring pattern A copper-based wiring pattern was formed on the seed layer of the substrate using a semi-additive method. Specifically, the following operations were performed.

[0269] A dry film (photosensitive resist film, Resonac "RY-5115") was laminated on the seed layer of the substrate. The lamination of the dry film was performed as follows: using an intermittent vacuum pressure laminator (Nikko Materials "V-160"), the pressure was reduced for 30 seconds to below 13 hPa, and then pressed for 30 seconds at 100°C and 0.4 MPa. Next, a glass mask (exposure mask) with a wiring pattern (L / S = 10 μm / 500 μm) was placed on the dry film, and irradiated with light using a projection exposure machine (Ushio Electric Co., Ltd. "UX-2240"). Next, a 1% sodium carbonate solution at 30°C was sprayed at a jet pressure of 0.15 MPa for 60 seconds. After that, it was washed with water and developed. Through the development of the dry film, a wiring pattern with a comb pattern (L / S = 10 / 500 μm) exposing the seed layer was formed. After development, electrolytic copper plating was performed, forming an 11μm thick electrolytic copper plating layer on the seed crystal layer.

[0270] Using a silica solution (with an average particle size of 85 nm) as a slurry and a CMP urethane pad, a portion of the dry film and electrolytic copper plating on the substrate was polished for 7 minutes to achieve high alignment and surface smoothing of the electrolytic copper plating. This polishing was performed in the stacking direction under conditions of 3 psi (approximately 20.7 kPa) pressure, 30 rpm sample rotation speed, and 31 rpm turntable rotation speed. Subsequently, the dry film was peeled off to obtain a copper-based wiring pattern. This substrate is designated as substrate A.

[0271] (3) Lamination of resin sheet 1 (Lamination of coating resin composition layers) On the wiring pattern of substrate A, the resin sheet 1 obtained in Manufacturing Example 1 above is laminated in such a way that the coating resin composition layer and the wiring pattern are in contact. The lamination of the resin sheet 1 is performed as follows: using an intermittent vacuum pressure laminator (Nikko Materials' "V-160"), the pressure is reduced for 30 seconds to adjust the pressure to below 13 hPa, and then pressed for 30 seconds at a temperature of 80°C and a pressure of 0.3 MPa. After lamination, the support in the resin sheet 1 is peeled off. Through this peeling, a substrate B is obtained having a layer structure of coating resin composition layer (surface layer) / copper-based wiring pattern and coating resin composition layer (intermediate layer) / seed layer (metal layer) / silicon wafer.

[0272] (4) Lamination of the second substrate and curing of the resin composition layer for coating (formation of the first coating layer) An 8-inch thick glass wafer, serving as a second substrate, was laminated onto a coating resin composition layer (surface layer) of substrate B. This lamination was performed as follows: using an intermittent vacuum pressure laminator (Nikko Materials' "V-160"), the pressure was reduced to below 13 hPa for 30 seconds, and then pressed for 30 seconds at 80°C and 0.3 MPa. After laminating the glass wafer, it was placed in an oven at 100°C for 60 minutes, followed by heating in an oven at 150°C for 30 minutes to thermally cure the coating resin composition layer. This curing process formed the first coating layer. This substrate is designated as substrate C.

[0273] (5) Removal of the first substrate In substrate C, a grinding machine (DISCO's "DAG810") was used to remove the silicon wafer substrate, which serves as the first substrate, by grinding. The grinding operation ended at the point when the Ti / Cu seed layer (metal layer) in the first substrate was exposed to the entire plane. The substrate obtained through this operation is designated as substrate D.

[0274] (6) Forming a recess corresponding to the wiring pattern Substrate D was subjected to etching using an etchant to remove the copper-based wiring pattern and seed layer (metal layer). The Ti etching operation used a 1:1:2 mixture of Meltex's "Melstrip Ti-3991":H2O2:pure water as the Ti etchant and was performed at room temperature. The Cu etching operation used a 1:1 mixture of Mitsubishi Gas Chemical's "WLC-C2":pure water as the Cu etchant and was performed at room temperature. Through these etching operations, a substrate E with recesses corresponding to the wiring pattern was obtained.

[0275] (7) Lamination of resin sheet 2 (lamination of core resin composition layers) and curing of core resin composition layers (formation of core substrate layer) On the recessed side of substrate E, the resin sheet 2 obtained in Manufacturing Example 2 above is laminated such that the core resin composition layer is embedded in the recess. The lamination of the resin sheet 2 is performed as follows: using an intermittent vacuum pressure laminator (Nikko Materials Co., Ltd. "V-160"), the pressure is reduced for 30 seconds to adjust to below 13 hPa, and then pressed for 30 seconds at a temperature of 80°C and a pressure of 0.3 MPa. After laminating the resin sheet 2, it is placed in an oven at 100°C and heated for 60 minutes to cure the core resin composition layer. Through this curing, a core substrate layer is formed.

[0276] (8) Core layer formation (grinding of the core substrate layer) A portion of the core substrate layer was milled using a silica solution (with an average particle size of 85 nm) as a slurry and a CMP urethane pad. This milling was performed in the stacking direction under conditions of a pressure of 3 psi (approximately 20.7 kPa), a sample rotation speed of 30 rpm, and a turntable rotation speed of 31 rpm, ending at the point where the surface of the first coating layer was flush with the core substrate layer. This milling process formed the core layer. This substrate is designated as substrate F.

[0277] (9) Lamination of resin sheet 1 and curing of the resin composition layer for coating (formation of the second coating layer) In substrate F, the resin sheet 1 obtained in Manufacturing Example 1 above is laminated in such a way that the coating resin composition layer is in contact with the core layer and the first coating layer. The lamination of the resin sheet 1 is performed as follows: using an intermittent vacuum pressure laminator (Nikko Materials' "V-160"), the pressure is reduced for 30 seconds to adjust to below 13 hPa, and then pressed for 30 seconds at a temperature of 80°C and a pressure of 0.3 MPa. After laminating the resin sheet 1, it is placed in an oven at 100°C and heated for 60 minutes, and then transferred to an oven at 150°C and heated for 30 minutes to heat-cur the coating resin composition layer. Through this curing, the second coating layer is formed.

[0278] Through the above operations, using thermosetting resin, an optical waveguide with L / S=10μm / 500μm can be obtained.

[0279] <Experimental Example 1: Determination of Minimum Melt Viscosity> The melt viscosity of the resin composition layers in resin sheets 1 and 2 obtained in Manufacturing Examples 1 and 2 above was measured using a dynamic viscoelasticity measuring apparatus (UBM Rheosol-G3000). The measurement was performed on 1g samples collected from the resin composition layers using a parallel plate with a diameter of 18mm. The measurement conditions were as follows: initial temperature 60°C to 200°C, heating rate 5°C / min, temperature interval 2.5°C, and vibration 1Hz / deg. The minimum melt viscosity was calculated based on the measured melt viscosity values.

[0280] <Experimental Example 2: Determination of Tensile Modulus of Elasticity> The resin composition layers in resin sheets 1 and 2 obtained in manufacturing examples 1 and 2 above were cured by heating them at 150°C for 60 minutes. The support was peeled off from the resin sheet to obtain a cured resin composition layer. This cured layer was cut into dumbbell-shaped pieces (No. 1) to obtain test pieces. The tensile strength of the test pieces was measured using an ORIENTEC RTC-1250A tensile testing machine, and the tensile modulus of elasticity at 23°C was determined. The measurement was performed according to JIS K 7127. Five measurements were performed, and the average value of the five points was calculated.

[0281] The results of Experiments 1 and 2 are shown in Table 1 below.

[0282] [Table 1] [Table 1. Results of Experiments 1 and 2] <Experimental Example 3: Evaluation Test of Embedding Performance> A silicon wafer with a recess (trench structure) of 5 μm width and 5 μm depth (thickness) was prepared. The resin sheet 2 obtained in Manufacturing Example 2 above was laminated such that a core resin composition layer was embedded in the recess of the silicon wafer. The lamination of the resin sheet 2 was performed as follows: using an intermittent vacuum pressure laminator (Nikko Materials' "V-160"), the pressure was reduced for 30 seconds to below 13 hPa, and then pressed for 30 seconds at a temperature of 80°C and a pressure of 0.3 MPa. After laminating the resin sheet 2, it was placed in an oven at 100°C for 60 minutes to cure the core resin composition layer. Through this curing, a core substrate layer was formed. This substrate was used as evaluation substrate α.

[0283] For the evaluation substrate α, cross-sectional observation was performed using a FIB-SEM composite apparatus (ETHOSNX5000 manufactured by Hitachi High Technologies). Specifically, FIB (Focused Ion Beam) cutting was used to create a cross-section parallel to the thickness direction of the core substrate layer (a cross-section parallel to the stacking direction). This cross-section was then observed using SEM. The observed images confirmed the absence of voids larger than 1 μm in diameter. This experiment demonstrates that the optical waveguide manufacturing method according to the present invention can yield an optical waveguide with excellent embedding properties.

[0284] <Example 4: Evaluation Test of the Abrasiveness of the Coating Layer> For the substrate E obtained in “(6) Formation of the recess” above, a platinum film was formed on the recess side of the substrate E by vapor deposition. Except for the vapor deposition operation, the same operations as “(7) Lamination of resin sheet 2 (Lamination of core resin composition layer) and curing of core resin composition layer (formation of core base layer)” and “(8) Formation of core layer (grinding of core base layer)” were performed to obtain an evaluation substrate β in which the boundary between the core layer and the first coating layer can be confirmed.

[0285] For the evaluation substrate β, cross-sectional observation was performed using a FIB-SEM composite apparatus (ETHOSNX5000 manufactured by Hitachi High Technology Corporation). Specifically, FIB (Focused Ion Beam) cutting was used to create a cross-section parallel to the thickness direction of the core layer (parallel to the stacking direction). This cross-section was then observed using SEM. The observed images confirmed that no height difference exceeding 200 nm occurred between the core layer and the first cladding layer. This experiment demonstrates that, according to the waveguide manufacturing method of the present invention, an optical waveguide with excellent cladding layer abrasiveness can be obtained.

[0286] <Example 5: Evaluation Test of Dimensional Stability of Core Pattern> For the substrate E obtained in “(6) Formation of the recess” above, a sputtered film with Ti / Cu = 20 / 100 nm was formed by sputtering. Except for the sputtering film formation operation, the same operations as “(7) Lamination of resin sheet 2 (Lamination of core resin composition layer) and curing of core resin composition layer (formation of core substrate layer)”, “(8) Formation of core layer (grinding of core substrate layer)” and “(9) Lamination of resin sheet 1 and curing of coating resin composition layer (formation of second coating layer)” were performed to obtain an evaluation substrate γ whose core pattern width and height could be confirmed. For the evaluation substrate γ, cross-sectional observation was performed using a FIB-SEM composite apparatus (ETHOS NX5000 manufactured by Hitachi High Technology Co., Ltd.). Specifically, FIB (Focused Ion Beam) cutting was used to produce a cross-section parallel to the thickness direction of the core pattern (a cross-section parallel to the lamination direction). This cross-section was observed by SEM. In the observed images, the width and height of the core pattern at 5 selected locations were measured. In this measurement, it was confirmed that the width and height of the core pattern were 10 μm ± 1 μm at all five locations. This experiment demonstrates that the optical waveguide manufacturing method according to the present invention can produce an optical waveguide with excellent dimensional stability.

[0287] Explanation of reference numerals in the attached figures 10 Optical waveguide 100 core layers 100A core layer incident side end 100B core layer emission side end 100I Core layer and cladding layer interface 110 Second resin composition layer 111 Core substrate layer (cured second resin composition layer) 200 coating layers 210 First resin composition layer 211 First Coating Layer (Cureable First Resin Composition Layer) 220 Third resin composition layer 221 Second coating layer (cured third resin composition layer) 300 Substrate with a metal layer (first substrate) 301 First substrate material substrate portion 302 metal layer The portion of the 302S metal layer not covered by the mask layer 310 Metal-based wiring patterns 400 mask layers 500 recess.

Claims

1. A method for manufacturing an optical waveguide, comprising the following steps: In step (i), a metal-based wiring pattern is formed on the metal layer of a substrate (first substrate) with a metal layer. Step (ii) involves forming a first resin composition layer from an encapsulating resin composition in a manner that contacts the metal layer and the wiring pattern, and curing the first resin composition layer to form a first encapsulating layer. Step (iii): Remove the substrate portion of the first substrate; Step (iv): Remove the metal layer and the wiring pattern to form a recess corresponding to the wiring pattern; Step (v) involves forming a second resin composition layer from a core resin composition comprising a thermosetting resin in a manner that contacts the recess, and curing the second resin composition layer to form a core base layer. Step (vi) involves removing a portion of the core substrate layer to form the core layer; as well as Step (vii) involves forming a third resin composition layer from the coating resin composition in contact with the core layer and the first coating layer, and then curing the third resin composition layer to form the second coating layer.

2. The manufacturing method according to claim 1, wherein, Step (ii) includes step (ii-1): on the side of the first resin composition layer opposite to the substrate (first substrate) with the metal layer, the support (second substrate) is bonded to the first resin composition layer.

3. The manufacturing method according to claim 2, wherein, Following step (vii), the process further includes step (viii): removing the support (second substrate).

4. The manufacturing method according to claim 2, wherein, The support (second substrate) is a glass substrate, a single-crystal silicon substrate, or a silicon substrate with an inorganic film. The silicon substrate having the inorganic film has an inorganic film comprising a silicon oxide film on the surface bonded to the first resin composition layer.

5. The manufacturing method according to claim 1, wherein, The metal layer portion of the substrate with the metal layer (first substrate) contains copper.

6. The manufacturing method according to claim 1, wherein, Process (iv) includes process (iv-1): forming a recess by removing the metal layer and the wiring pattern using a wet process with an etching solution.

7. The manufacturing method according to claim 1, wherein, The substrate portion of the metal-layered substrate (first substrate) is a glass substrate, a single-crystal silicon substrate, or a silicon substrate with an inorganic film. The silicon substrate having an inorganic film has an inorganic film comprising a silicon oxide film between the metal layer and the silicon substrate.

8. The manufacturing method according to claim 1, wherein, Process (iii) includes process (iii-1): peeling off the substrate portion of the first substrate.

9. The manufacturing method according to claim 1, wherein, Step (iii) includes step (iii-2): grinding the substrate portion of the first substrate.

10. The manufacturing method according to claim 1, wherein, Process (vi) includes process (vi-1): forming a core layer by grinding a portion of the core substrate layer through chemical mechanical polishing (CMP).

11. The manufacturing method according to claim 1, wherein, The coating resin composition comprises a thermosetting resin.

12. The manufacturing method according to claim 1, wherein, The process after step (i) and before step (ii) further includes step (ii'): planarizing the surface of the wiring pattern by chemical mechanical polishing (CMP).

13. The manufacturing method according to claim 1, wherein, The width of the core layer is less than 10 μm.

14. The manufacturing method according to claim 1, wherein, The manufactured optical waveguide is a single-mode optical waveguide.

15. The manufacturing method according to claim 1, wherein, At a wavelength of 1310 nm, the refractive index of the cured core resin composition is set as n. core Furthermore, the refractive index of the cured resin composition for coating is set as n. clad Under the condition that the following relationship is satisfied: n core -n clad ≤0.1。 16. The manufacturing method according to claim 1, wherein, The core resin composition comprises one or more resins selected from epoxy resin, (meth)acrylic resin, phenolic resin and silicone resin.

17. The manufacturing method according to claim 1, wherein, The coating resin composition comprises one or more resins selected from epoxy resin, (meth)acrylic resin, phenolic resin and silicone resin.

18. An optoelectronic hybrid substrate comprising an optical waveguide manufactured by any one of claims 1 to 17.

19. A semiconductor device comprising the optoelectronic hybrid substrate of claim 18.

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