JP5309992B2 - Dry film for forming optical waveguide, optical waveguide and method for producing the same - Google Patents

Abstract

A dry film from which an optical waveguide having high dimensional accuracy, satisfactory transmission characteristics, and excellent flex resistance can be easily produced in a short time. The dry film (1) comprises a base film (2), an uncured photosensitive resin composition layer (3), and a cover film (4) which have been superposed in this order. The photosensitive resin composition layer (3) comprises (A) a polymer comprising repeating units represented by the following formulae (1) and (2): (1) (2) (wherein R<SUP>1</SUP> and R<SUP>2</SUP> each independently is hydrogen or alkyl; R<SUP>3</SUP> is (meth)acryloyl; X is a single bond or a divalent organic group; and Y is an unpolymerizable organic group), (B) a compound which contains a linear structure formed by the reaction of a polyol compound with a polyisocyanate compound and having urethane bonds repeatedly and has two to six (meth)acryloyl groups, (C) a compound having one or more ethylenically unsaturated groups per molecule, and (D) a photo-radical polymerization initiator.

Description

  The present invention relates to a dry film for forming an optical waveguide, an optical waveguide, and a manufacturing method thereof. More specifically, a dry film capable of forming each part (clad layer, etc.) of an optical waveguide with high shape accuracy, good transmission characteristics, and excellent bending resistance by a simple manufacturing process, and The present invention relates to an optical waveguide manufactured using a dry film, and a method for manufacturing the optical waveguide.

In the multimedia era, optical waveguides are attracting attention as optical transmission media because of the demand for large capacity and high speed information processing in optical communication systems and computers.
A typical example of such an optical waveguide is a silica-based waveguide, which is generally manufactured by the following process.
(1) A lower cladding layer made of a glass film is formed on a silicon substrate by a technique such as flame deposition (FHD) or CVD.
(2) On the lower clad layer, an inorganic thin film having a different refractive index is formed, and this thin film is patterned using a reactive ion etching method (RIE) to form a core portion.
(3) Further, an upper clad layer is formed by a flame deposition method.

However, such a method for manufacturing a silica-based waveguide has problems such as requiring a special manufacturing apparatus and taking a long manufacturing time.
In order to solve such a problem, an optical waveguide is manufactured using a dry film (also referred to as a dry film resist) in which a base film and an uncured photosensitive resin composition layer are laminated. A method has been proposed.
For example, a method for forming an optical waveguide using a dry film resist comprising a base film and at least two photosensitive resin layers having different refractive indexes after curing, and after laminating the dry film resist on a substrate, Using a photo tool on which the desired optical waveguide pattern is drawn, irradiate a predetermined amount of light onto the dry film resist to cure the predetermined place by radiation, and then remove the unexposed portion using a developer. Thus, a method of forming an optical waveguide in which a cladding layer is formed above and below a core layer has been proposed ( Patent Document 1 ).
According to this method, a specific dry film resist is laminated on a substrate, irradiated with a predetermined amount of light, and then developed in a short time, compared with a conventional method for producing a silica-based waveguide. In addition, the optical waveguide can be formed at low cost.

However, the optical waveguide formed by this method is coated with a coating layer using a liquid resist or the like for the purpose of protecting the optical waveguide because the sidewall is air and the core layer is exposed. Therefore, in addition to the dry film resist, there is a problem that other resists such as a liquid resist are necessary and an additional step for forming the coating layer is required.
(A) a polymer having a carboxyl group, a polymerizable group and other organic group, (b) a compound having two or more polymerizable reactive groups in the molecule, and (c) a radiation polymerization initiator, A dry film having a layer made of a photosensitive resin composition is proposed ( Patent Document 2 ).

JP-A-6-258537 JP 2003-195080 A

According to the knowledge found by the present inventors, according to the conventional dry film ( Patent Document 2 ) containing the components (a) to (c) described above, an optical waveguide having high shape accuracy and excellent transmission characteristics can be obtained. Can be manufactured.
However, an optical waveguide formed using this dry film has a problem that cracks and breaks occur when it is bent in the form of a film-like cured product.
The present invention is intended to solve the above-described problems of the prior art, and can easily manufacture an optical waveguide having high shape accuracy, good transmission characteristics (waveguide loss), and excellent bending resistance. An object is to provide a dry film that can be formed by a process.

  As a result of intensive studies to solve the above problems, the present inventor has achieved the accuracy of shape by using a dry film having a layer made of a photosensitive resin composition containing a plurality of types of components having a specific chemical structure. It was found that an optical waveguide having high transmission characteristics and excellent bending resistance can be formed by a simple manufacturing process, and the present invention has been completed.

（式中、Ｒ^１及びＲ^２は各々独立して水素原子又は炭素数１〜１２のアルキル基であり、Ｒ^３は（メタ）アクリロイル基であり、Ｘは単結合又は２価の有機基であり、Ｙは重合性を有しない有機基である。）
（Ｂ）脂肪族ポリエーテルポリオールとポリイソシアネート化合物とが反応して生じる、ウレタン結合を繰り返し有する直鎖構造を含み、かつ、２〜６個の（メタ）アクリロイル基を有する化合物、
（Ｃ）分子内に１個以上のエチレン性不飽和基を有する化合物、並びに、
（Ｄ）光ラジカル重合開始剤、
を含有する感光性樹脂組成物からなることを特徴とする光導波路形成用ドライフィルム。
［２］ 上記一般式（１）が、下記一般式（３）で表される構造である上記［１］に記載の光導波路形成用ドライフィルム。

（式中、Ｒ^１は水素原子又は炭素数１〜１２のアルキル基であり、Ｒ^３は（メタ）アクリロイル基であり、Ｗ及びＺは各々独立して単結合又は２価の有機基である。）
［３］ ゲルパーミエーションクロマトグラフィーで測定したポリスチレン換算の上記（Ｂ）成分の数平均分子量が１，０００〜１００，０００である上記［１］又は［２］に記載の光導波路形成用ドライフィルム。
［４］ 上記（Ｂ）成分が、脂肪族ポリエーテルポリオール、ポリイソシアネート化合物及び水酸基含有（メタ）アクリレートの反応生成物である上記［１］〜［３］のいずれかに記載の光導波路形成用ドライフィルム。
［５］ 上記感光性樹脂組成物層の厚さが１〜２００μｍである上記［１］〜［４］のいずれかに記載の光導波路形成用ドライフィルム。
［６］ 上記感光性樹脂組成物層における上記ベースフィルムとは反対側の面に、カバーフィルムが積層されている上記［１］〜［５］のいずれかに記載の光導波路形成用ドライフィルム。
［７］ 下部クラッド層と、コア部分と、上部クラッド層とを含む光導波路であって、少なくとも、下部クラッド層及び上部クラッド層が、上記［１］〜［６］のいずれかに記載の光導波路形成用ドライフィルムの感光性樹脂組成物層の硬化物からなることを特徴とする光導波路。
［８］ 下部クラッド層と、コア部分と、上部クラッド層とを含む光導波路であって、少なくとも、下部クラッド層、コア部分、及び上部クラッド層のいずれか１つが、上記［１］〜［６］のいずれかに記載の光導波路形成用ドライフィルムの感光性樹脂組成物層の硬化物からなり、かつ、該硬化物からなる部分以外の部分が、上記感光性樹脂組成物層と同様の（Ａ）成分〜（Ｄ）成分を含有する液状の感光性樹脂組成物の硬化物からなることを特徴とする光導波路。
［９］ 上記下部クラッド層、コア部分及び上部クラッド層が、上記［１］〜［６］のいずれかに記載の光導波路形成用ドライフィルムの感光性樹脂組成物層の硬化物からなり、かつ、上記コア部分の屈折率が、上記下部クラッド層と上記上部クラッド層のいずれの屈折率よりも０．１％以上大きいことを特徴とする光導波路。
［１０］ 下部クラッド層と、コア部分と、上部クラッド層とを含む光導波路の製造方法であって、下部クラッド層を形成する工程と、コア部分を形成する工程と、上部クラッド層を形成する工程とを含み、かつ、少なくとも、下部クラッド層を形成する工程、及び、上部クラッド層を形成する工程が、上記［１］〜［６］のいずれかに記載の光導波路形成用ドライフィルムの感光性樹脂組成物層を光照射して硬化させる工程を含むことを特徴とする光導波路の製造方法。
［１１］ 下部クラッド層と、コア部分と、上部クラッド層とを含む光導波路の製造方法であって、下部クラッド層を形成する工程と、コア部分を形成する工程と、上部クラッド層を形成する工程とを含み、少なくとも、下部クラッド層を形成する工程、コア部分を形成する工程、及び、上部クラッド層を形成する工程のいずれか１つが、上記［１］〜［６］のいずれかに記載の光導波路形成用ドライフィルムの感光性樹脂組成物層を光照射して硬化させる工程を含み、上記感光性樹脂組成物層を光照射して硬化させる部分以外の部分を形成する工程が、上記感光性樹脂組成物層と同様の（Ａ）成分〜（Ｄ）成分を含有する液状の感光性樹脂組成物を光照射して硬化させる工程を含むことを特徴とする光導波路の製造方法。 That is, the present invention provides the following [1] to [11].
[1] A dry film for forming an optical waveguide in which a base film and an uncured photosensitive resin composition layer are laminated, wherein the photosensitive resin composition layer comprises the following components (A) to (D) )component:
(A) a polymer containing repeating units represented by the following general formulas (1) and (2),

Wherein R ¹ and R ² are each independently a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, R ³ is a (meth) acryloyl group, and X is a single bond or a divalent organic group. And Y is an organic group having no polymerizability.)
(B) a compound comprising a linear structure having a urethane bond repeatedly, which is generated by a reaction between an aliphatic polyether polyol and a polyisocyanate compound, and having 2 to 6 (meth) acryloyl groups,
(C) a compound having one or more ethylenically unsaturated groups in the molecule, and
(D) a photoradical polymerization initiator,
A dry film for forming an optical waveguide, comprising a photosensitive resin composition containing
[2] The dry film for forming an optical waveguide according to the above [1], wherein the general formula (1) is a structure represented by the following general formula (3).

Wherein R ¹ is a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, R ³ is a (meth) acryloyl group, and W and Z are each independently a single bond or a divalent organic group. .)
[3] The dry film for forming an optical waveguide according to the above [1] or [2], wherein the number average molecular weight of the component (B) in terms of polystyrene measured by gel permeation chromatography is 1,000 to 100,000. .
[4] For forming an optical waveguide according to any one of [1] to [3], wherein the component (B) is a reaction product of an aliphatic polyether polyol , a polyisocyanate compound, and a hydroxyl group-containing (meth) acrylate. Dry film.
[5] The dry film for forming an optical waveguide according to any one of [1] to [4], wherein the photosensitive resin composition layer has a thickness of 1 to 200 μm.
[6] The dry film for forming an optical waveguide according to any one of [1] to [5], wherein a cover film is laminated on a surface of the photosensitive resin composition layer opposite to the base film.
[7] An optical waveguide including a lower clad layer, a core portion, and an upper clad layer, wherein at least the lower clad layer and the upper clad layer are the light according to any one of [1] to [6]. An optical waveguide comprising a cured product of a photosensitive resin composition layer of a dry film for forming a waveguide.
[8] An optical waveguide including a lower cladding layer, a core portion, and an upper cladding layer, wherein at least one of the lower cladding layer, the core portion, and the upper cladding layer is the above [1] to [6] ] Is a cured product of the photosensitive resin composition layer of the dry film for forming an optical waveguide according to any one of the above, and a portion other than the cured product is the same as the above photosensitive resin composition layer ( An optical waveguide comprising a cured product of a liquid photosensitive resin composition containing the components A) to (D).
[9] The lower cladding layer, the core portion, and the upper cladding layer are made of a cured product of the photosensitive resin composition layer of the dry film for forming an optical waveguide according to any one of [1] to [6], and An optical waveguide characterized in that the refractive index of the core portion is at least 0.1% greater than the refractive index of either the lower cladding layer or the upper cladding layer.
[10] A method of manufacturing an optical waveguide including a lower cladding layer, a core portion, and an upper cladding layer, the step of forming a lower cladding layer, the step of forming a core portion, and the formation of an upper cladding layer And the step of forming the lower clad layer and the step of forming the upper clad layer at least include the steps of photosensitivity of the dry film for forming an optical waveguide according to any one of the above [1] to [6] The manufacturing method of the optical waveguide characterized by including the process of irradiating and hardening a photosensitive resin composition layer.
[11] A method of manufacturing an optical waveguide including a lower cladding layer, a core portion, and an upper cladding layer, the step of forming a lower cladding layer, the step of forming a core portion, and the formation of an upper cladding layer At least one of the step of forming the lower cladding layer, the step of forming the core portion, and the step of forming the upper cladding layer according to any one of the above [1] to [6]. Including a step of irradiating and curing the photosensitive resin composition layer of the optical waveguide forming dry film, and the step of forming a portion other than the portion to be cured by irradiating the photosensitive resin composition layer The manufacturing method of the optical waveguide characterized by including the process of irradiating and hardening the liquid photosensitive resin composition containing the (A) component-(D) component similar to the photosensitive resin composition layer.

  According to the dry film having the specific photosensitive resin composition layer of the present invention, an optical waveguide having high shape accuracy, good transmission characteristics (waveguide loss), and excellent bending resistance can be easily produced. The process can be manufactured efficiently and in a short time.

It is sectional drawing which shows an example of the dry film of this invention typically. It is a flowchart which shows an example of the manufacturing method of the optical waveguide of this invention.

The dry film of the present invention is formed by laminating a base film such as a polyethylene terephthalate film and an uncured photosensitive resin composition layer containing a specific component.
In this specification, “dry film” means at least a base film that is a support for the photosensitive resin composition layer, and an uncured photosensitive resin composition layer that is laminated on one side of the base film. Is defined as a film with
The components (A) to (D) and other optional components constituting the photosensitive resin composition layer of the dry film of the present invention will be described in detail below.

（式中、Ｒ^１及びＲ^２は各々独立して水素原子又は炭素数１〜１２のアルキル基であり、Ｒ^３は（メタ）アクリロイル基であり、Ｘは単結合又は２価の有機基であり、Ｙは重合性を有しない有機基である。） [(A) component]
(A) component used by this invention is a polymer (for example, random copolymer) containing the repeating unit represented by the following general formula (1) and (2).

Wherein R ¹ and R ² are each independently a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, R ³ is a (meth) acryloyl group, and X is a single bond or a divalent organic group. And Y is an organic group having no polymerizability.)

（式中、Ｒ^１は水素原子又は炭素数１〜１２のアルキル基であり、Ｒ^３は（メタ）アクリロイル基であり、Ｗ及びＺは各々独立して単結合又は２価の有機基である。） R ¹ and R ² in the general formulas (1) and (2) are each independently a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, preferably a hydrogen atom or an alkyl having 1 to 5 carbon atoms. A group, more preferably a hydrogen atom or a methyl group.
Preferable examples of the repeating unit represented by the general formula (1) include a repeating unit represented by the following general formula (3).

Wherein R ¹ is a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, R ³ is a (meth) acryloyl group, and W and Z are each independently a single bond or a divalent organic group. .)

（式中、Ｒ^４はメチレンまたは炭素数２〜８のアルキレン基である。）
一般式（３）中のＺ（２価の有機基）の例としては、−（ＣＨ_２）_ｎ−Ｏ−（式中、ｎは１〜８の整数である。）等が挙げられる。 Here, examples of W (divalent organic group) in the general formula (3) include a structure represented by the following general formula (4), a phenylene group, and the like.

(In the formula, R ⁴ is methylene or an alkylene group having 2 to 8 carbon atoms.)
Examples of Z (divalent organic group) in the general formula (3) include — (CH ₂ ) _n —O— (wherein n is an integer of 1 to 8).

（式中、Ｒ^５は炭素数１〜２０の直鎖状、分岐状又は環状の炭素鎖を有する基である。） Examples of Y in the general formula (2) include a structure represented by the following general formula (5), a phenyl group, a cyclic amide group, a pyridyl group, and the like.

(In the formula, R ⁵ is a group having a linear, branched or cyclic carbon chain having 1 to 20 carbon atoms.)

  The weight average molecular weight of the component (A) in terms of polystyrene is preferably 2,000 to 100,000, more preferably 5,000 to 100,000, more preferably 8,000 to 70,000, particularly preferably 10,000. 000 to 50,000. When the value is less than 5,000, the viscosity of the composition becomes small, and it may be difficult to form a photosensitive resin composition layer having a certain thickness when producing a dry film. When the value exceeds 100,000, there are disadvantages such that the viscosity of the composition is increased and the applicability of the photosensitive resin composition is deteriorated when a dry film is produced.

As a method for producing the component (A), for example, a radically polymerizable compound having a hydroxyl group (a) and a component (b) (radically polymerizable compound corresponding to the general formula (2)) were radically polymerized in a solvent. Then, the method of adding the isocyanate which has (c) (meth) acryloyloxy group with respect to the hydroxyl group of the side chain of the obtained copolymer is mentioned.
The compounds (a) to (c) used in this method will be described.

The compound (a) (radical polymerizable compound having a hydroxyl group) reacts with a hydroxyl group in the compound and an isocyanate group (—N═C═O) in the compound (c) to form a urethane bond (—NH—COO). -) And a structural unit having a side chain portion containing a (meth) acryloyloxy group derived from the compound (c) is used to introduce into the component (A).
Examples of the compound (a) include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, hydroxymethyl (meth) acrylate, and 4-hydroxycyclohexyl (meth). An acrylate etc. are mentioned.
A compound (a) is used individually by 1 type or in combination of 2 or more types.
The content of the compound (a) in the component (A) is preferably 3 to 80% by mass, more preferably 7 to 60% by mass, and particularly preferably 10 to 40% by mass.
When the content is less than 3% by mass, curing tends to be insufficient. If the content exceeds 80% by mass, it may be difficult to adjust the refractive index.

The compound (b) (compound corresponding to the structure of the general formula (2)) is mainly used for appropriately controlling the mechanical properties and refractive index of the component (A).
Examples of the compound (b) include methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, sec-butyl (meth) acrylate, and t-butyl (meth) acrylate. (Meth) acrylic acid alkyl esters such as dicyclopentanyl (meth) acrylate, cyclohexyl (meth) acrylate and other esters of (meth) acrylic acid and cyclic hydrocarbon compounds; phenyl (meth) acrylate, benzyl ( (Meth) acrylate aryl esters such as (meth) acrylate, o-phenylphenol glycidyl ether (meth) acrylate, p-cumylphenoxyethylene glycol acrylate; tribromophenol ethoxy (meth) acrylate, 2,2,2-to Halogenation of fluoromethyl (meth) acrylate, 2,2,3,3-tetrafluoropropyl (meth) acrylate, 1H, 1H, 5H-octafluoropentyl (meth) acrylate, perfluorooctylethyl (meth) acrylate and the like ( (Meth) acrylic acid esters; aromatic vinyls such as styrene, α-methylstyrene, m-methylstyrene, p-methylstyrene, vinyltoluene, p-methoxystyrene; 1,3-butadiene, isoprene, 1,4- Conjugated diolefins such as dimethylbutadiene; nitrile group-containing polymerizable compounds such as acrylonitrile and methacrylonitrile; amide bond-containing polymerizable compounds such as acrylamide and methacrylamide; and fatty acid vinyls such as vinyl acetate.
Of these, dicyclopentanyl (meth) acrylate, methyl (meth) acrylate, n-butyl (meth) acrylate, styrene, α-methylstyrene and the like are preferably used.
A compound (b) is used individually by 1 type or in combination of 2 or more types.
(A) The content rate of the compound (b) in a component becomes like this. Preferably it is 15-92 mass%, More preferably, it is 25-84 mass%, Most preferably, it is 35-78 mass%.
If the content is less than 15% by mass, it may be difficult to adjust the refractive index. If the content exceeds 92% by mass, curing tends to be insufficient.

Examples of the compound (c) (isocyanate having a (meth) acryloyloxy group) include 2-methacryloxyethyl isocyanate, N-methacryloyl isocyanate, methacryloxymethyl isocyanate, 2-acryloxyethyl isocyanate, N-acryloyl isocyanate, acryl Examples include loxymethyl isocyanate.
(A) The content rate of the compound (c) in a component becomes like this. Preferably it is 5-80 mass%, More preferably, it is 9-60 mass%, Most preferably, it is 12-45 mass%.
When the content is less than 5% by mass, curing tends to be insufficient. If the content exceeds 80% by mass, it may be difficult to adjust the refractive index.

  The component (A) can also include structural units not described in the general formulas (1) and (2). Examples of the compound for introducing such a structural unit (hereinafter referred to as compound (d)) include dicarboxylic acid diesters such as diethyl maleate, diethyl fumarate, diethyl itaconate; vinyl chloride, vinylidene chloride, etc. And a chlorine-containing polymerizable compound. (A) Content rate of the compound (d) in a component becomes like this. Preferably it is 0-20 mass%, More preferably, it is 0-10 mass%.

In the process of producing the component (A), various additives such as a thermal polymerization inhibitor, a storage stabilizer, and a curing catalyst can be added during the addition reaction of the compound (c).
The thermal polymerization inhibitor is blended in order to suppress a polymerization reaction due to heat. Examples of thermal polymerization inhibitors include pyrogallol, benzoquinone, hydroquinone, methylene blue, tert-butylcatechol, monobenzyl ether, methoxyphenol, amylquinone, amyloxyhydroquinone, n-butylphenol, phenol, hydroquinone monopropyl ether and the like.
Examples of the storage stabilizer include 2,6-di-t-butyl-p-cresol, benzoquinone, p-toluquinone, p-xyloquinone, phenyl-α-naphthylamine and the like.
Examples of the curing catalyst include dibutyltin dilaurate, dioctyltin dilaurate, dibutyltin dioleate, dibutyltin diacetate, tetramethoxytitanium, tetraethoxytitanium and the like.
The total compounding amount of these various additives is usually 10 parts by mass or less, preferably 5 parts by mass or less with respect to 100 parts by mass of the total amount of the compounds (a) to (c).

Examples of the solvent that can be used for radical polymerization of the compound (a), the compound (b), and the compound (d) used as necessary in the production of the component (A) include methanol, ethanol, ethylene glycol, diethylene glycol, Alcohols such as propylene glycol; cyclic ethers such as tetrahydrofuran and dioxane; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl Ether, diethylene glycol ethyl methyl ether, propylene glycol monomethyl Alkyl ethers of polyhydric alcohols such as ether and propylene glycol monoethyl ether; alkyl ether acetates of polyhydric alcohols such as ethylene glycol ethyl ether acetate, diethylene glycol ethyl ether acetate, propylene glycol ethyl ether acetate and propylene glycol monomethyl ether acetate; Aromatic hydrocarbons such as toluene and xylene; Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, 4-hydroxy-4-methyl-2-pentanone, diacetone alcohol; ethyl acetate, butyl acetate, ethyl lactate, Ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, 2-hydroxy-2-methylpropion Esters such as ethyl, ethyl ethoxyacetate, hydroxyethyl acetate, methyl 2-hydroxy-3-methylbutanoate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl 3-ethoxypropionate Kind.
Of these, cyclic ethers, polyhydric alcohol alkyl ethers, polyhydric alcohol alkyl ether acetates, ketones, and esters are preferred.

  On the other hand, if a solvent having a hydroxyl group in the molecule is used as the solvent used in the addition reaction of compound (c) in the production of component (A), compound (c) reacts with the solvent, which is not preferable. . Therefore, the solvent used for the addition reaction of compound (c) is preferably one having no hydroxyl group. Examples of the solvent having no hydroxyl group include those having no hydroxyl group among the solvents used for the radical polymerization.

  Moreover, a normal radical polymerization initiator can be used as a catalyst for radical polymerization used for manufacture of (A) component. Examples of radical polymerization initiators include 2,2′-azobisisobutyronitrile, 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (4-methoxy-2, Azo compounds such as 4-dimethylvaleronitrile); organic peroxides such as benzoyl peroxide, lauroyl peroxide, t-butylperoxypivalate, 1,1′-bis (t-butylperoxy) cyclohexane; and hydrogen peroxide Can be mentioned. When a peroxide is used as the radical polymerization initiator, a redox initiator may be used in combination with a reducing agent.

  It is preferable that the glass transition temperature of (A) component obtained by the said method is 20 to 150 degreeC. At this time, the glass transition temperature is normally defined using a differential scanning calorimeter (DSC). When the glass transition temperature of the component (A) is less than 20 ° C., it becomes difficult to form the photosensitive resin composition layer on the base film, or the photosensitive resin composition layer becomes sticky, There are disadvantages such as poor workability when the dry film is laminated on the substrate. Conversely, when the glass transition temperature of the component (A) exceeds 150 ° C., the photosensitive resin composition layer of the dry film becomes hard or brittle, and the dry film is laminated on the substrate. Sometimes the adhesion is worse.

[Component (B)]
The component (B) is a compound having a linear structure having a urethane bond repeatedly and having 2 to 6 (meth) acryloyl groups, produced by a reaction between an aliphatic polyether polyol and a polyisocyanate compound. .
The component (B) is obtained, for example, by reacting an aliphatic polyether polyol , a polyisocyanate compound, and a hydroxyl group-containing (meth) acrylate.
As a manufacturing method of (B) component, the following manufacturing methods 1-4 are mentioned, for example.
Production method 1: A method in which an aliphatic polyether polyol , a polyisocyanate compound, and a hydroxyl group-containing (meth) acrylate are charged and reacted together.
Production method 2: A method in which an aliphatic polyether polyol and a polyisocyanate compound are reacted, and then a hydroxyl group-containing (meth) acrylate is reacted.
Production method 3: A method in which a polyisocyanate compound and a hydroxyl group-containing (meth) acrylate are reacted, and then an aliphatic polyether polyol is reacted.
Production Method 4: A method in which a polyisocyanate compound and a hydroxyl group-containing (meth) acrylate are reacted, then an aliphatic polyether polyol is reacted, and finally a hydroxyl group-containing (meth) acrylate is reacted again.
Among production methods 1 to 4, production methods 2 to 4 are preferable for controlling the molecular weight distribution.

(1) Aliphatic polyether polyol One of the raw materials of the component (B) of the present invention is an aliphatic polyether polyol (hereinafter sometimes referred to as a polyol compound) .
Among these, in order to further improve the adhesion between the substrate and the optical waveguide, it is preferable to use a polyether polyol compound containing an alkyleneoxy structure.
As the aliphatic polyether polyol, at least one compound selected from ethylene oxide, propylene oxide, butylene oxide, tetrahydrofuran, 2-methyltetrahydrofuran, 3-methyltetrahydrofuran, substituted tetrahydrofuran, oxetane, substituted oxetane, tetrahydropyran and oxeban is used. Examples thereof include those obtained by ring-opening (co) polymerization. Specific examples include polyethylene glycol, 1,2-polypropylene glycol, 1,3-polypropylene glycol, polytetramethylene glycol, 1,2-polybutylene glycol, polyisobutylene glycol, copolymer polyol of propylene oxide and tetrahydrofuran, ethylene Copolymer polyol of oxide and tetrahydrofuran, copolymer polyol of ethylene oxide and propylene oxide, copolymer polyol of tetrahydrofuran and 3-methyltetrahydrofuran, copolymer polyol of ethylene oxide and 1,2-butylene oxide .

Examples of commercially available aliphatic polyether polyols include Unisafe DC1100, Unisafe DC1800, Unisafe DCB1100, Unisafe DCB1800 (above, manufactured by NOF Corporation); PPTG4000, PPTG2000, PPTG1000, PTG2000, PTG3000, PTG650, PTGL2000, PTGL1000 (above, Exonol 4020, EXENOL 3020, EXENOL 2020, EXENOL 1020 (above, manufactured by Asahi Glass Co., Ltd.); PBG3000, PBG2000, PBG1000, Z3001 (above, made by Daiichi Kogyo Seiyaku Co., Ltd.); (The above, manufactured by Sumika Bayer Urethane Co., Ltd.); NPML-2002, 3002, 4002, 8002 (above, manufactured by Asahi Glass Co., Ltd.).

Among the polyol compounds, polypropylene glycol, ethylene oxide / propylene oxide copolymer diol, ethylene oxide / 1,2-butylene oxide copolymer diol, and propylene oxide / tetrahydrofuran copolymer diol are preferable, and ethylene oxide / 1,2-butylene. An oxide copolymer diol is more preferred.
The number average molecular weight of the polyol compound is preferably 400 to 10,000, more preferably 1,000 to 8,000, and most preferably 1,500 to 5,000. When the number average molecular weight is less than 400, the Young's modulus of the cured product at normal temperature and low temperature is increased, and it becomes difficult to obtain sufficient bending resistance. On the other hand, when the number average molecular weight exceeds 10,000, the viscosity of the composition increases, and the coating property when the composition is coated on a substrate may be deteriorated.

(2) Polyisocyanate compound The polyisocyanate compound which is one of the raw materials of the component (B) of the present invention is a compound having two or more isocyanate groups in the molecule. Examples of such compounds include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, 1,5-naphthalene diisocyanate, and m-phenylene. Diisocyanate, p-phenylene diisocyanate, 3,3′-dimethyl-4,4′-diphenylmethane diisocyanate, 4,4′-diphenylmethane diisocyanate, 3,3′-dimethylphenylene diisocyanate, 4,4′-biphenylene diisocyanate, 1,6 -Hexane diisocyanate, isophorone diisocyanate, methylene bis (4-cyclohexyl isocyanate), 2,2,4-trimethylhexamethylene diisocyanate, 1,4-hexamethylene diisocyanate, Diisocyanate compounds such as (2-isocyanatoethyl) fumarate, 6-isopropyl-1,3-phenyl diisocyanate, 4-diphenylpropane diisocyanate, lysine diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate, tetramethylxylylene diisocyanate, etc. Can be mentioned.
Of these, hydrogenated xylylene diisocyanate, isophorone diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate and the like are preferable. These polyisocyanate compounds may be used alone or in combination of two or more.

(3) Hydroxyl group-containing (meth) acrylate The hydroxyl group-containing (meth) acrylate which is one of the raw materials of the component (B) of the present invention is a compound having a hydroxyl group and a (meth) acryloyl group in the molecule. Examples of such compounds include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2-hydroxy-3-phenyloxypropyl (meth) acrylate, 4 -Hydroxybutyl (meth) acrylate, 2-hydroxyalkyl (meth) acryloyl phosphate, 4-hydroxycyclohexyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, neopentyl glycol mono (meth) acrylate, trimethylolpropane di ( And (meth) acrylate, trimethylolethane di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, and the like. Furthermore, the compound obtained by addition reaction of a glycidyl group containing compound and (meth) acrylic acid, such as alkyl glycidyl ether, allyl glycidyl ether, and glycidyl (meth) acrylate, is mentioned.
Of these, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and the like are preferable.

The mixing ratio of each raw material constituting the component (B) of the present invention is, for example, 0.5 to 2 mol of a polyol compound and 1 to 2.5 mol of a polyisocyanate compound with respect to 1 mol of a hydroxyl group-containing (meth) acrylate. is there.
The number average molecular weight (polystyrene conversion value measured by gel permeation chromatography) of the component (B) of the present invention is preferably 1,000 to 100,000, more preferably 3,000 to 60,000, particularly preferably. 5,000 to 30,000. When the number average molecular weight is less than 1,000, it is difficult to obtain sufficient bending resistance for a cured product (for example, a clad layer) of the photosensitive resin composition layer. Further, when the number average molecular weight exceeds 100,000, the viscosity of the photosensitive resin composition becomes too high, and the coating property when forming the composition layer by applying the photosensitive resin composition on the base film. May get worse.

  The amount of component (B) in the composition of the present invention is preferably 10 to 100 parts by weight, more preferably 20 to 80 parts by weight, and particularly preferably 30 to 70 parts by weight with respect to 100 parts by weight of component (A). Part by mass. When the amount is less than 10 parts by mass, sufficient bending resistance may not be obtained for a cured product of the photosensitive resin composition layer (for example, a clad layer), and when the amount exceeds 100 parts by mass, The compatibility with the component (A) may deteriorate, resulting in film roughness on the surface of the cured product (for example, the clad layer) of the photosensitive resin composition layer, or sufficient transparency may not be obtained.

[Component (C)]
Component (C) is a compound having one or more ethylenically unsaturated groups in the molecule.
Here, examples of the ethylenically unsaturated group include a (meth) acryloyl group and a vinyl group.
The molecular weight of the component (C) is preferably less than 2,000, more preferably less than 1,000. Moreover, it is preferable that the boiling point in 0.1 MPa of (C) component is 130 degreeC or more.
Preferred examples of the component (C) having two or more ethylenically unsaturated groups in the molecule include two or more (meth) acryloyl groups and / or vinyl groups in the molecule, and a molecular weight of less than 1,000. The compound of this is mentioned.
In this case, all of the ethylenically unsaturated groups in the molecule may be any one of acryloyl group, methacryloyl group, and vinyl group, or acryloyl group and methacryloyl group, acryloyl group and vinyl group, and methacryloyl group. And a combination of any two of vinyl group, or a combination of three types of acryloyl group, methacryloyl group and vinyl group.

Examples of (meth) acrylates having two (meth) acryloyl groups in the molecule include ethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, 1,4 -Butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, tris (2-hydroxyethyl) isocyanurate di (meth) acrylate, bis (hydroxymethyl) ) Addition of tricyclodecane di (meth) acrylate, di (meth) acrylate of diol which is an adduct of bisphenol A ethylene oxide or propylene oxide, addition of ethylene oxide or propylene oxide of hydrogenated bisphenol A Di (meth) acrylate of diol, epoxy (meth) acrylate obtained by adding (meth) acrylate to diglycidyl ether of bisphenol A, diacrylate of polyoxyalkylenated bisphenol A, 9,9-bis [4- ( 2-acryloyloxyethoxy) phenyl] fluorene and the like.
Examples of (meth) acrylates having 3 or more (meth) acryloyl groups in the molecule include compounds in which 3 mol or more of (meth) acrylic acid is ester-bonded to a polyhydric alcohol having 3 or more hydroxyl groups, for example, Trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, trimethylolpropane trioxyethyl (meth) acrylate, tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate Etc.
Moreover, polyether acrylic oligomer, polyester acrylic oligomer, or polyepoxy acrylic oligomer having polyether or polyester in the main chain can also be used.

  Examples of (meth) acrylate having one (meth) acryloyl group in the molecule include dimethylaminoethyl (meth) acrylate, acryloylmorpholine, dimethylacrylamide, diethylacrylamide, diisopropylacrylamide, diacetoneacrylamide, and isobutoxymethyl. (Meth) acrylamide, N-vinylpyrrolidone, N-vinylcaprolactam, isobornyl (meth) acrylate, dicyclopentenyl acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, 3-hydroxy-1 -Adamantyl (meth) acrylate, methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate , Cyclohexyl (meth) acrylate, isoamyl (meth) acrylate, isooctyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, benzyl (meth) acrylate, dicyclopentadienyl (meth) acrylate, tricyclo Decanyl (meth) acrylate, 2-acryloylcyclohexyl succinic acid, tetrahydrofurfuryl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, butoxyethyl (meth) acrylate, alkyl alcohol (1-8 carbon atoms) ) Of (meth) acrylate of alcohol which is an adduct of ethylene oxide, (meth) acrylate of alcohol which is an adduct of ethylene oxide of phenol, p-cumylphenol (Meth) acrylate of alcohol which is an adduct of tylene oxide, (meth) acrylate of alcohol which is an adduct of ethylene oxide of nonylphenol, o-phenylphenol glycidyl ether (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-phenoxyethyl ( (Meth) acrylate, ethyl carbitol (meth) acrylate, 2-ethylhexyl (meth) acrylate, 3-hydroxycyclohexyl acrylate, tribromophenol ethoxy (meth) acrylate Rate, 2,2,2-trifluoromethyl (meth) acrylate, 2,2,3,3-tetrafluoropropyl (meth) acrylate, 1H, 1H, 5H-octafluoropentyl (meth) acrylate, perfluorooctylethyl (Meth) acrylate etc. are mentioned.

These commercial products include Iupimer UV
SA1002, SA2007 (above, manufactured by Mitsubishi Chemical Corporation), Viscoat # 150, # 155, # 160, # 190, # 192, # 195, # 230, # 215, # 260, # 295, # 300, # 335HP, # 360, # 400, # 540, # 700, 3F, 3FM, 4F, 8F, 8FM, 2-MTA, 2-ETA, V-MTG, 3PA, GPT, HEA, HPA, 4-HBA, AIB, IOAA, LA STA (Osaka Organic Chemical Co., Ltd.), light ester M, E, NB, IB, EH, ID, L, L-7, TD, L-8, S, 130MA, 041MA, CH, THF, BZ, PO, IB-X, HO, HOP, HOA, HOP-A, HOB, DM, DE, HO-MS, EG, 2EG, 1.4BG, 1.6HX, 1.9ND, 1.10DC TMP, G-101P, G-201P, BP-2EM, BP-4EM, BP-6EM, MTG, BO, BC, 3EG, 4EG, 9EG, 14EG, NP, FM-108, G-201P, light acrylate IO- A, HOB-A, TMP-3EO-A, FA-108, IAA, LA, SA, BO-A, EC-A, MTG-A, 130A, DPM-A, PO-A, P- 200A, NP-4EA, NP-8EA, THF-A, IB-XA, HOA, HOP-A, M-600A, HOA-MS, 3EG-A, 4EG-A, 9EG-A, 14EG-A, NP- A, MPD-A, 1.6HX-A, BEPG-A, 1.9ND-A, MOD-A, DCP-A, BP-4EA, BP-4PA, BP-10EA, TMP-A, TMP-6EO- 3A, P -3A, PE-4A, DPE-6A, BA-104, BA-134 (above, Kyoeisha Chemical Co., Ltd.), KAYARAD
MANDA, HX-220, HX-620, R-551, R-712, R-604, R-684, PET-30, GPO-303, TMPTA, DPHA, D-310, D-330, DPCA-20, -30, -60, -120 (Nippon Kayaku Co., Ltd.), Aronix M208, M210, M215, M220, M240, M305, M309, M310, M315, M325, M400, M1200, M6100, M6200, M6250, M7100 M8030, M8060, M8100, M8530, M8560, M9050 (above, manufactured by Toagosei Co., Ltd.), NK ester # 401P, NK ester A-BPEF, NK ester A-CMP-1E (above, manufactured by Shin Nakamura Chemical Co., Ltd.) New Frontier BR-31 (Daiichi Kogyo Seiyaku Co., Ltd.), Lipoxy VR-77, VR-60, VR-90 (manufactured by Showa Polymer Co., Ltd.), Ebecryl 81, 83, 600, 629, 645, 745, 754, 767, 701, 755, 705, 770, 800, 805, 810, 830, 450, 1830, 1870 (manufactured by Daicel UCB), beam sets 575, 551B, 502H, 102 (manufactured by Arakawa Chemical Co., Ltd.), adamantate HA, HM (manufactured by Idemitsu Kosan Co., Ltd.), etc. Is mentioned.

(C) A component is used individually by 1 type or in combination of 2 or more types.
(C) The compounding quantity of a component becomes like this. Preferably it is 5-100 mass parts with respect to 100 mass parts of (A) component, More preferably, it is 10-70 mass parts, Most preferably, it is 15-50 mass parts. When the amount is less than 5 parts by mass, the accuracy of the shape of the target waveguide may be inferior when forming the optical waveguide. When the amount exceeds 100 parts by mass, it is in phase with the component (A). The solubility may deteriorate, and film roughness may occur on the surface of the cured product.

[(D) component]
The component (D) is a photo radical polymerization initiator capable of generating an active species (radical species) capable of polymerizing an ethylenically unsaturated group by light irradiation.
Here, light means ionizing radiation such as infrared rays, visible rays, ultraviolet rays, and X-rays, electron beams, α rays, β rays, and γ rays.
Examples of the photo radical polymerization initiator include acetophenone, acetophenone benzyl ketal, 1-hydroxycyclohexyl phenyl ketone, 2,2-dimethoxy-2-phenylacetophenone, xanthone, fluorenone, benzaldehyde, fluorene, anthraquinone, triphenylamine, carbazole, 3-methylacetophenone, 4-chlorobenzophenone, 4,4′-dimethoxybenzophenone, 4,4′-diaminobenzophenone, Michler's ketone, benzoin propyl ether, benzoin ethyl ether, benzyldimethyl ketal, 1- (4-isopropylphenyl) -2 -Hydroxy-2-methylpropan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, thioxanthone, diethylthio Xanthone, 2-isopropylthioxanthone, 2-chlorothioxanthone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, And bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide.

Commercially available radical photopolymerization initiators include, for example, Irgacure 184, 369, 651, 500, 819, 907, 784, 2959, CGI 1700, CGI 1750, CGI 11850, CG 24-61, Darocur 1116, 1173 (and above, Ciba Specialty Chemicals). Co., Ltd.), Lucirin TPO, TPO-L (above, manufactured by BASF), Ubekrill P36 (manufactured by UCB), and the like.
A radical photopolymerization initiator is used individually by 1 type or in combination of 2 or more types.
The content rate of (D) component in the photosensitive resin composition of this invention becomes like this. Preferably it is 0.1-10 mass%, More preferably, it is 0.2-5 mass%. When the content is less than 0.1% by mass, curing does not proceed sufficiently, and a problem may occur in the transmission characteristics of the optical waveguide. On the other hand, if the content exceeds 10% by mass, the photopolymerization initiator may adversely affect long-term transmission characteristics.

In this invention, a photosensitizer can be mix | blended with the above-mentioned photoinitiator. If a photosensitizer is used in combination, energy rays such as light can be absorbed more effectively.
Photosensitizers include, for example, thioxanthone, diethylthioxanthone and thioxanthone derivatives; anthraquinone, bromoanthraquinone and anthraquinone derivatives; anthracene, bromoanthracene and anthracene derivatives; perylene and perylene derivatives; xanthone, thioxanthone and thioxanthone derivatives; And ketocoumarin. What is necessary is just to select the kind of photosensitizer according to the kind of photoinitiator.

In the resin composition of the present invention, in addition to the above components (A) to (D), if necessary, for example, one polymerizable group in the molecule is used as long as the characteristics of the resin composition of the present invention are not impaired. A compound having a reactive group or a polymer resin (for example, epoxy resin, acrylic resin, polyamide resin, polyamideimide resin, polyurethane resin, polybutadiene resin, polychloroprene resin, polyether resin, polyester resin, styrene-butadiene block copolymer) Petroleum resin, xylene resin, ketone resin, cellulose resin, fluoropolymer, silicone polymer) and the like.
Furthermore, various additives as necessary, for example, antioxidants, ultraviolet absorbers, light stabilizers, silane coupling agents, coating surface improvers, thermal polymerization inhibitors, leveling agents, surfactants, colorants, Storage stabilizers, plasticizers, lubricants, fillers, inorganic particles, anti-aging agents, wettability improvers, antistatic agents and the like can be blended.

Here, examples of the antioxidant include Irganox 1010, 1035, 1076, 1222 (manufactured by Ciba Specialty Chemicals Co., Ltd.), Antigene P, 3C, FR, and Sumilizer (manufactured by Sumitomo Chemical Co., Ltd.). Examples of ultraviolet absorbers include Tinuvin P, 234, 320, 326, 327, 328, 329, 213 (and above, manufactured by Ciba Specialty Chemicals), Seesorb 102, 103, 110, 501, 202, 712, and 704 (and above). , Manufactured by Sipro Kasei Co., Ltd.). Examples of the light stabilizer include Tinuvin 292, 144, 622LD (manufactured by Ciba Specialty Chemicals), Sanol LS770 (manufactured by Sankyo Co., Ltd.), Sumisorb TM-061 (manufactured by Sumitomo Chemical Co., Ltd.) and the like. Examples of the silane coupling agent include γ-aminopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, and the like, and commercially available products such as SH6062 and SZ6030 (above, Toray Dow Corning Silicone Co., Ltd.), KBE903, 603, 403 (manufactured by Shin-Etsu Chemical Co., Ltd.). Examples of the coating surface improver include silicone additives such as dimethylsiloxane polyether, and commercially available products include DC-57, DC-190 (manufactured by Dow Corning), SH-28PA, SH-29PA, SH. -30PA, SH-190 (above, manufactured by Toray Dow Corning Silicone), KF351, KF352, KF353, KF354 (above, manufactured by Shin-Etsu Chemical Co., Ltd.), L-700, L-7002, L-7500, FK- 024-90 (manufactured by Nihon Unicar).
In order to prepare the photosensitive resin composition, the components described above may be mixed and stirred according to a conventional method.

Hereinafter, the dry film of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view schematically showing an example of the dry film of the present invention, and FIG. 2 is a flowchart showing an example of a method for producing an optical waveguide using the dry film of the present invention.
In FIG. 1, a dry film 1 of the present invention is obtained by laminating a base film 2, a photosensitive resin composition layer 3, and a cover film 4 in this order.
Examples of the material of the base film 2 include polyethylene terephthalate and polyethylene naphthalate. The base film 2 is preferably transparent from the viewpoint of light transmittance.
The thickness of the base film 2 is preferably 5 to 500 μm, more preferably 10 to 300 μm, particularly preferably from the viewpoints of mechanical strength as a support for the photosensitive resin composition layer 3 and reduction in material cost. Is 12-100 μm.
The base film 2 is subjected to a surface treatment on the contact surface with the photosensitive resin composition layer 3 so that the base film 2 can be easily peeled off from the cured product of the photosensitive resin composition layer 3 when the dry film 1 is used. I can leave. Examples of the surface treatment method include application of a silicone release agent.
The thickness of the photosensitive resin composition layer 3 corresponds to the thickness of the core part and the clad layer formed by the composition layer 3 and is usually 1 to 200 μm.

The photosensitive resin composition layer 3 is an uncured photosensitive resin composition. The photosensitive resin composition layer 3 is formed on the base film 2 as a layer having a certain thickness and having plasticity that can be deformed by pressure.
The cover film 4 is a member provided as necessary. Therefore, the dry film of this invention can also be formed only with a base film and the photosensitive resin composition layer.
Examples of the material of the cover film 4 include polypropylene, polyethylene, polyethylene terephthalate, and the like.
Although the thickness of the cover film 4 is not specifically limited, Usually, it is 5-100 micrometers.
The cover film 4 is subjected to a surface treatment on the contact surface with the photosensitive resin composition layer 3 so that the cover film 4 can be easily peeled off from the cured product of the photosensitive resin composition layer 3 when the dry film 1 is used. I can leave. Examples of the surface treatment method include application of a silicone release agent.

As a method of forming the photosensitive resin composition layer 4 on the base film 2, a method of directly applying the photosensitive resin composition on the base film 2, or dissolving the photosensitive resin composition in an organic solvent. After applying using a method such as spin coating method, dipping method, spray method, bar coating method, roll coating method, curtain coating method, gravure printing method, silk screen method, or inkjet method, using a dryer or the like The method of scattering a solvent is mentioned.
As an organic solvent in this case, the organic solvent used at the time of preparation of the copolymer of the component (A) can be used. In particular, the boiling point is in the range of 80 to 160 ° C., and each component is Those that can be dissolved uniformly are preferred. These organic solvents can be used alone or in admixture of two or more. The temperature condition for scattering the organic solvent is preferably 30 to 150 ° C, more preferably 50 to 140 ° C.
The compounding amount of the organic solvent is preferably 10 to 150 parts by mass with respect to 100 parts by mass of the total amount of the components (A) to (D). In addition, the amount of the organic solvent remaining after drying is preferably 20 parts by mass or less, where the total amount of the photosensitive resin composition and the organic solvent after the organic solvent is dispersed is 100 parts by mass.
In addition, in the dry film of this invention, the said photosensitive resin composition layer can also be laminated | stacked on a base film as needed.

Next, an example of a method for manufacturing an optical waveguide using the dry film of the present invention will be described with reference to FIG.
The manufacturing method of the optical waveguide 37 of the present invention includes a step of forming the lower clad layer 16 on the substrate 10 ((a) to (e) in FIG. 2) and a step of forming the core portion 27 (in FIG. 2). (F) to (i)) and a step of forming the upper clad layer 36 ((j) to (m) in FIG. 2).
In the present invention, among these three steps, at least one of the step of forming the lower clad layer 16, the step of forming the core portion 27, and the step of forming the upper clad layer 36 is as described above. This is a step of forming a cured product (such as the lower clad layer 16) using a dry film having a photosensitive resin composition layer. In this case, the other part (the lower clad layer 16, the core part 27, or the upper clad layer 36) formed without using the dry film contains the liquid components (A) to (D). It is preferably formed of a photosensitive resin composition.
However, FIG. 2 shows an embodiment in which all of the lower cladding layer 16, the core portion 27, and the upper cladding layer 36 are formed using a dry film.
In addition, the photosensitive resin composition prepared for forming each part of the lower cladding layer 16, the core portion 27, and the upper cladding layer 36 is, for convenience, a lower layer composition, a core composition, and an upper layer respectively. This is called a composition. Moreover, the dry film which has the photosensitive resin composition layer formed from the composition for lower layers, the composition for cores, and the composition for upper layers, respectively, the dry film for lower layers, the dry film for cores, and the dry film for upper layers Called.

(1) Preparation of photosensitive resin composition and production of dry film The composition of each of the lower layer composition, the core composition and the upper layer composition is as follows: lower clad layer 16, core portion 27 and upper clad layer 36 The relationship of the refractive index of each part is determined so as to satisfy the conditions required for the optical waveguide. Specifically, two or three types of photosensitive resin compositions having an appropriate difference in refractive index are prepared, and among these, a photosensitive resin composition that gives a cured film having the highest refractive index is prepared. The composition for the core is used, and another photosensitive resin composition is used as the composition for the lower layer and the composition for the upper layer.
The lower layer composition and the upper layer composition are preferably the same photosensitive resin composition in terms of economy and production control.
At least one of the lower layer composition, the core composition, and the upper layer composition is applied on the base film by the method described above and used as the photosensitive composition layer of the dry film. That is, (i) a method in which only the core portion is formed using the dry film, and the lower cladding layer and the upper cladding layer are formed of a liquid photosensitive resin composition, (ii) the lower cladding layer and the core portion Of forming the upper cladding layer with a liquid photosensitive resin composition, and (iii) forming the lower cladding layer, the core portion and the upper cladding layer with a dry film. (Iv) A method in which the lower clad layer and the upper clad layer are formed using a dry film, and the core portion is formed of a liquid photosensitive resin composition can be employed.

(2) Preparation of Substrate First, as shown in FIG. 2A, a substrate 10 having a flat upper surface is prepared. Although it does not specifically limit as a kind of board | substrate 10, For example, a silicon substrate, a glass substrate, a glass epoxy resin, a polyimide substrate etc. can be used.
(3) Formation process of lower cladding layer In this process, the lower cladding layer 16 is formed on the upper surface of the substrate 10. Specifically, as shown in FIG. 2 (b), after preparing a lower layer dry film 11 (consisting of a base film 12, a photosensitive resin composition layer 13 and a cover film 14), a lower layer dry film is prepared. The cover film 14 is peeled off from the film 11, and then the laminate composed of the base film 12 and the photosensitive resin composition layer 13 on the upper surface of the substrate 10 with the photosensitive resin composition layer 13 side facing downward. The body is laminated ((c) of FIG. 2). Then, it prebakes as needed and forms the thin film for lower layers. The lower layer thin film is irradiated with light (ultraviolet rays) 15 and cured to form a lower clad layer 16 which is a cured product of the photosensitive resin composition layer 13 on the substrate 10 ((d) in FIG. 2). After the formation of the lower clad layer 16, heat treatment (post-bake) is performed as necessary, and then the base film 12 is peeled off to obtain a laminate in which the lower clad layer 16 is formed on the substrate 10 ( (E) of FIG.
Here, as a laminating method (transfer method) of the dry film 11, while applying appropriate heat and pressure using a pressure bonding method such as a normal pressure hot roll pressure bonding method, a vacuum heat roll pressure bonding method, or a vacuum heat press pressure bonding method. And a method of transferring onto the substrate 10.
The pre-baking of the laminated body ((c) in FIG. 2) composed of the base film 12 and the photosensitive resin composition layer 13 is performed at a temperature of 50 to 150 ° C. for the purpose of promoting curing and removing the residual solvent.
The irradiation amount of the light 15 at the time of forming the lower cladding layer 16 is not particularly limited, but light with a wavelength of 200 to 390 nm and an illuminance of 1 to 500 mW / cm ² is applied with an irradiation amount of 10 to 5,000 mJ. It is preferable to perform exposure by irradiating so as to be / cm ² .
Visible light, ultraviolet light, infrared light, X-rays, α-rays, β-rays, and γ-rays can be used as the type of light 15 to be irradiated, but ultraviolet light is particularly preferable. For example, a high-pressure mercury lamp, a low-pressure mercury lamp, a metal halide lamp, or an excimer lamp is preferably used as the light irradiation device. In the step of forming the lower clad layer 16, it is preferable to irradiate the entire surface of the thin film with light and harden the whole.
It is preferable to further perform heat treatment (post-bake) so that the entire coating film is sufficiently cured after exposure. Although this heating condition changes with the compounding composition of the photosensitive resin composition, the kind of additive, etc., Usually, it is 30-200 degreeC, Preferably it is 50-150 degreeC, if it is set as the heating condition for 5 minutes-3 hours, for example. good.
Note that the pre-baking conditions, light irradiation amount, type, light irradiation device, and the like in the lower clad layer forming step are the same in the core portion forming step and the upper clad layer forming step described later.

(4) Core Part Formation Step This is a step of forming the core portion 27 on the upper surface of the lower cladding layer 16. Specifically, as shown in FIG. 2 (f), after preparing a core dry film 21 (consisting of a base film 22, a photosensitive resin composition layer 23, and a cover film 24), a core dry film is prepared. The cover film 24 is peeled from the film 21, and then the base film 22 and the photosensitive resin composition layer 23 are placed on the upper surface of the lower clad layer 16 with the photosensitive resin composition layer 23 side facing downward. A laminated body is laminated ((g) in FIG. 2). Thereafter, pre-baking is performed as necessary to form a core thin film.
Thereafter, the upper surface of the core thin film is irradiated with light (ultraviolet rays) 25 via a predetermined pattern forming means (for example, a photomask having a predetermined line pattern) ((h) in FIG. 2). ). As a result, in the photosensitive resin composition layer 23 constituting the core thin film, only the portion irradiated with light is cured, and the other portions remain uncured. Thereafter, the base film 22 is peeled off, and the uncured portion is removed by development processing, whereby a core portion 27 made of a patterned cured film can be formed on the lower clad layer 16 (FIG. 2). (I)).
The conditions such as pre-baking and light irradiation are the same as those for forming the lower cladding layer.
Next, in order to further harden the core portion 27, it is post-baked for 5 to 180 minutes, for example, at a temperature of 30 to 150 ° C. by a heating device such as a hot plate or an oven.

In FIG. 2H, the method of irradiating light according to a predetermined pattern is not limited to a method using a photomask composed of a light transmitting portion and a non-transmitting portion. For example, the following a to c A method is mentioned.
a. A method using electro-optical means for forming a mask image composed of a light transmitting region and a light non-transmitting region according to a predetermined pattern, using the same principle as that of a liquid crystal display device.
b. A method of irradiating light through an optical fiber corresponding to a predetermined pattern in the light guide member using a light guide member formed by bundling a large number of optical fibers.
c. A method of irradiating laser light or convergent light obtained by a condensing optical system such as a lens or a mirror while scanning.
The thin film that has been pattern-exposed and selectively cured in this manner according to a predetermined pattern can be developed using the difference in solubility between the cured portion and the uncured portion. Accordingly, after the pattern exposure, the uncured portion is removed and the cured portion is left, so that the core portion 27 can be formed as a result.

An organic solvent can be used as the developer used in the development process. Examples of the organic solvent include acetone, methanol, ethanol, isopropyl alcohol, ethyl lactate, propylene glycol monomethyl ether acetate, methyl amyl ketone, methyl ethyl ketone, cyclohexanone, propylene glycol monomethyl ether, and the like.
The development time is usually 30 to 600 seconds. As a developing method, a known method such as a liquid piling method, a dipping method, or a shower developing method can be employed. After the development, the organic solvent is removed by air drying as it is, and a patterned thin film is formed.

(5) Formation of upper clad layer In this process, the upper clad layer 36 is formed on the upper surfaces of the lower clad layer 16 and the core portion 27 to complete the optical waveguide 37. Specifically, as shown in FIG. 2 (j), after preparing an upper layer dry film 31 (consisting of a base film 32, a photosensitive resin composition layer 33, and a cover film 34), an upper layer dry film 31 is prepared. The cover film 34 is peeled from the film 31, and then the base film 32 and the photosensitive resin composition with the photosensitive resin composition layer 33 facing downward on the upper surfaces of the lower cladding layer 16 and the core portion 27. A laminate composed of the layer 33 is laminated ((k) in FIG. 2). Then, it prebakes as needed and forms the thin film for upper layers. The upper thin film is irradiated with light (ultraviolet rays) 35 and cured to form an upper clad layer 36 which is a cured product of the photosensitive resin composition layer 33 on the lower clad layer 16 and the core portion 27 (see FIG. 2 (l)). After forming the lower clad layer 36, if necessary, heat treatment (post-bake) is performed, and then the base film 32 is peeled off to obtain the optical waveguide 37 ((m) in FIG. 2).
The conditions such as pre-baking, light irradiation, and post-baking are the same as those for forming the lower cladding layer.

In place of any one or two of the dry films 11, 21, and 31 in the method shown in FIG. 2, a liquid photosensitive resin composition having the same component composition as the photosensitive resin composition used in the dry film of the present invention. Things can also be used.
In this case, the lower layer composition, the core composition, or the upper layer composition is formed by spin coating, dipping, spraying, bar coating, roll coating, curtain coating, gravure printing, silk screen, inkjet. It is preferably applied by any method such as a method, dried or pre-baked to form a thin film, irradiated with light, and then post-baked as necessary.
When using a liquid photosensitive resin composition, as a light irradiation method, light having a wavelength of 200 to 450 nm and an illuminance of 1 to 500 mW / cm ² is irradiated so that an irradiation amount is 10 to 5,000 mJ / cm ^2. Thus, exposure is preferable. As the kind of light and the irradiation device, the same ones as exemplified in the formation process of the lower clad layer can be mentioned.
When a liquid photosensitive resin composition is used, the post-baking conditions in the upper and lower cladding layer forming steps vary depending on the component composition of the photosensitive resin composition, but are usually 30 to 200 ° C., preferably 50 to 50 ° C. The heating time may be 170 ° C., more preferably 80 to 150 ° C., for example, 5 minutes to 3 hours. Moreover, the conditions of the post-baking in the formation process of a core part are 30-200 degreeC, More preferably, it is 5-150 minutes at 50-150 degreeC. By post-baking, a cured product (lower cladding layer, core portion, upper cladding layer) having excellent hardness and heat resistance can be obtained.

An optical waveguide 37 shown in FIG. 2 (m) shows a partial cross section of a film-shaped optical waveguide (waveguide film), and includes a lower cladding layer 16 fixed on the substrate 10, and a lower cladding. A core portion 27 having a specific width and an upper clad layer 36 formed on the core portion 27 and the lower clad layer 16 are formed on the upper surface of the layer 16. The core portion 27 is embedded in the lower cladding layer 16 and the upper cladding layer 36 that form the outer shape of the optical waveguide 37.
The thicknesses of the lower cladding layer 16, the core portion 27, and the upper cladding layer 36 are not particularly limited. For example, the thickness of the lower cladding layer 16 is 1 to 200 μm, the thickness of the core portion 27 is 3 to 200 μm, and the upper portion. The thickness of the clad layer 36 (the distance between the upper surface of the upper clad layer 36 and the upper surface of the core portion 27) is determined to be 1 to 200 μm.
Although the width | variety of the core part 27 is not specifically limited, For example, it is 1-200 micrometers.
The refractive index of the core portion 27 needs to be larger than any of the refractive indexes of the lower cladding layer 16 and the upper cladding layer 36. For example, for light having a wavelength of 400 to 1,600 nm, the refractive index of the core portion 27 is 1.420 to 1.650, and the refractive indexes of the lower cladding layer 16 and the upper cladding layer 36 are 1.400 to 1.648. In addition, it is preferable that the refractive index of the core portion 27 is at least 0.1% larger than the refractive indexes of the two cladding layers 16 and 36.

Hereinafter, the present invention will be specifically described by way of examples.
[1. Preparation of materials]
The following materials were prepared as the components (A) to (D).
[(A) component]
Preparation Example 1
After replacing the flask equipped with a dry ice / methanol reflux with nitrogen, 3 g of 2,2′-azobisisobutyronitrile as a polymerization initiator and 115 g of propylene glycol monomethyl ether acetate as an organic solvent were dissolved, and the polymerization initiator was dissolved. Stir until Subsequently, 20 g of hydroxyethyl methacrylate, 30 g of dicyclopentanyl methacrylate, 25 g of styrene, and 25 g of n-butyl acrylate were charged, and then gently stirred. Thereafter, the temperature of the solution was raised to 80 ° C., and polymerization was carried out at this temperature for 6 hours. Thereafter, 0.13 g of di-n-butyltin dilaurate and 0.05 g of 2,6-di-t-butyl-p-cresol were charged into the obtained solution, and 23.7 g of 2-methacryloxyethyl isocyanate was stirred. Was added dropwise so that the temperature was kept at 60 ° C. or lower. After completion of the dropwise addition, the mixture was reacted at 60 ° C. for 5 hours to obtain a polymer solution having a methacryl group in the side chain. Thereafter, the reaction product was dropped into a large amount of hexane to solidify the reaction product. Further, it was redissolved in tetrahydrofuran having the same mass as the coagulated product and coagulated again with a large amount of hexane. After performing this re-dissolution-coagulation operation three times in total, the obtained coagulated product was vacuum-dried at 40 ° C. for 48 hours to obtain the desired copolymer A-1.

Preparation Example 2
After substituting a flask equipped with a dry ice / methanol reflux with nitrogen, 3 g of 2,2′-azobisisobutyronitrile as a polymerization initiator and 150 g of ethyl lactate as an organic solvent were stirred until the polymerization initiator was dissolved. did. Subsequently, 20 g of methacrylic acid, 30 g of dicyclopentanyl methacrylate, 25 g of styrene, and 25 g of n-butyl acrylate were charged, and then gently stirred. Thereafter, the temperature of the solution was raised to 80 ° C., and polymerization was carried out at this temperature for 6 hours. Thereafter, 10.5 g of 3,4-epoxycyclohexylmethyl acrylate, 0.8 g of tetrabutylammonium bromide, and 0.1 g of p-methoxyphenol were added to the obtained solution, and the side chain was stirred at 80 ° C. for 7 hours. A polymer solution having an acrylic group was obtained. Thereafter, the reaction product was dropped into a large amount of hexane to solidify the reaction product. Further, it was redissolved in tetrahydrofuran having the same mass as the coagulated product and coagulated again with a large amount of hexane. After this re-dissolution / coagulation operation was performed three times in total, the obtained coagulated product was vacuum-dried at 40 ° C. for 48 hours to obtain the desired copolymer A-2.

Preparation Example 3
After substituting a flask equipped with a dry ice / methanol reflux with nitrogen, 1.5 g of 2,2′-azobis (2,4-dimethylvaleronitrile) as a polymerization initiator and 115 g of propylene glycol monomethyl ether acetate as an organic solvent were charged. The mixture was stirred until the polymerization initiator was dissolved. Subsequently, 20 g of hydroxyethyl methacrylate, 25 g of dicyclopentanyl methacrylate, 40 g of methyl methacrylate, and 15 g of n-butyl acrylate were charged, and then gently stirred. Thereafter, the temperature of the solution was raised to 70 ° C., and polymerization was performed at this temperature for 6 hours. Thereafter, 0.12 g of di-n-butyltin dilaurate and 0.05 g of 2,6-di-t-butyl-p-cresol were charged into the obtained solution, and 23.7 g of 2-methacryloxyethyl isocyanate was stirred. Was added dropwise so that the temperature was kept at 60 ° C. or lower. After completion of the dropwise addition, the mixture was reacted at 60 ° C. for 5 hours to obtain a polymer solution having a methacryl group in the side chain. Thereafter, the reaction product was dropped into a large amount of hexane to solidify the reaction product. Further, it was redissolved in tetrahydrofuran having the same mass as the coagulated product and coagulated again with a large amount of hexane. After this re-dissolution-coagulation operation was performed three times in total, the obtained coagulated product was vacuum-dried at 40 ° C. for 48 hours to obtain the desired copolymer A-3.

Preparation Example 4
After substituting the flask equipped with a dry ice / methanol reflux with nitrogen, 1 g of 2,2′-azobis (2,4-dimethylvaleronitrile) as a polymerization initiator and 150 g of ethyl lactate as an organic solvent were added. Stir until dissolved. Subsequently, 20 g of methacrylic acid, 25 g of dicyclopentanyl methacrylate, 35 g of methyl methacrylate, and 20 g of n-butyl acrylate were charged, and then gently stirred. Thereafter, the temperature of the solution was raised to 70 ° C., and polymerization was carried out at this temperature for 6 hours. Thereafter, 31.4 g of 3,4-epoxycyclohexylmethyl acrylate, 2.2 g of tetrabutylammonium bromide, and 0.1 g of p-methoxyphenol were added to the obtained solution, and the side chain was stirred at 80 ° C. for 7 hours. A polymer solution having an acrylic group was obtained. Thereafter, the reaction product was dropped into a large amount of hexane to solidify the reaction product. Further, it was redissolved in tetrahydrofuran having the same mass as the coagulated product and coagulated again with a large amount of hexane. After this re-dissolution / coagulation operation was performed three times in total, the obtained coagulated product was vacuum-dried at 40 ° C. for 48 hours to obtain the desired copolymer A-4.

Table 1 shows the raw material names and blending amounts used in the production of the copolymers A-1 to A-4.

[Component (B)]
In a reaction vessel equipped with a stirrer, 13.6 parts by mass of isophorone diisocyanate, 81.7 parts by mass of polypropylene glycol having a number average molecular weight of 2,000, 0.01 parts by mass of 2,6-di-t-butyl-p-cresol Was cooled to 5 to 10 ° C. While stirring, 0.05 parts by mass of di-n-butyltin dilaurate was added and the mixture was stirred for 2 hours while adjusting the temperature to be kept at 30 ° C. or lower, and then the temperature was raised to 50 ° C. and further stirred for 2 hours. . Subsequently, 4.7 parts by mass of 2-hydroxyethyl acrylate (100 parts by mass in total) was added dropwise, and after the completion of the addition, the reaction was performed at 50 to 70 ° C. for 1 hour. The reaction was terminated when the residual isocyanate was 0.1% by mass or less, and Compound B-1 was obtained.

[Component (C)]
Trimethylolpropane triacrylate (boiling point at 0.1 MPa: 315 ° C., manufactured by Osaka Organic Chemical Industry Co., Ltd.)
Tribromophenol ethoxy acrylate (melting point: about 50 ° C., Daiichi Kogyo Seiyaku Co., Ltd., New Frontier BR-31)
Tetrafluoropropyl acrylate (boiling point: 106 ° C./21 kPa, manufactured by Osaka Organic Chemical Industry Co., Ltd., Biscoat 4F)
Dipentaerythritol hexaacrylate [component (D)]
Photoradical polymerization initiator (trade name “Irgacure 369”, manufactured by Ciba Specialty Chemicals)
[(E) component (organic solvent)]
Ethyl lactate Propylene glycol monomethyl ether acetate

[2. Production of dry film]
The above-mentioned (A) component (copolymers A-1 to A-4) and (B) to (E) components were mixed at a blending ratio shown in Table 2 to obtain a uniform solution. Next, the obtained solution was applied on a polyethylene terephthalate film (film thickness: 50 μm) as a base film by spin coating, then dried at 120 ° C. for 10 minutes, and further on the surface of the coating film after drying, a cover film As described above, a polyethylene terephthalate film (film thickness: 25 μm) was pressure-bonded at normal pressure to obtain dry films J-1 to J-4 for the core having a photosensitive resin composition layer thickness of 50 μm. Moreover, the dry film J-5-J-10 for lower layers and upper layers was produced by the same method so that the thickness of the photosensitive resin composition layer might be 20 micrometers and 70 micrometers, respectively.

[3. Formation of optical waveguide]
[Example 1]
(A) Formation of lower clad layer The polyethylene terephthalate film which is the cover film of the dry film J-5 for the lower layer (thickness of the photosensitive resin composition layer: 20 μm) is peeled off and dried on the surface of the silicon substrate using a laminator. Film J-5 was transferred by a normal temperature normal pressure hot roll pressure bonding method. Next, the film made of the dry film J-5 was irradiated with ultraviolet rays having a wavelength of 365 nm and an illuminance of 10 mW / cm ² for 100 seconds to be photocured. After curing, the polyethylene terephthalate film as the base film was peeled off, and this cured film was post-baked at 150 ° C. for 1 hour to obtain a lower cladding layer having a thickness of 20 μm.

(B) Formation of core portion Next, a dry film for core J-1 (thickness of photosensitive resin composition layer: 50 μm) obtained by peeling off a polyethylene terephthalate film as a cover film in advance, on the lower clad layer, Using a laminator, the film is transferred by a room temperature, normal pressure, and hot roll pressure bonding method, and then the film having a wavelength of 365 nm and an illuminance of 10 mW / cm ² is passed through a photomask having a line-shaped pattern with a width of 50 μm on the dry film J-1. The film was cured by irradiation with ultraviolet rays for 100 seconds. Next, after peeling off the polyethylene terephthalate film, which is the base film, the substrate having a film obtained by partially curing the photosensitive resin composition layer is immersed in a developer composed of acetone, and the unexposed portion of the film Was dissolved. Thereafter, post-baking was performed at 150 ° C. for 1 hour to form a core portion having a line pattern having a width of 50 μm.

(C) Formation of Upper Cladding Layer Next, an upper dry film J-5 (thickness of the photosensitive resin composition layer: a polyethylene terephthalate film as a cover film) previously peeled off from the upper surface of the lower cladding layer having the core portion. 70 μm) was transferred by a normal pressure hot roll pressing method (temperature: 80 ° C.). Thereafter, the film made of the dry film J-5 was irradiated with ultraviolet rays having a wavelength of 365 nm and an illuminance of 10 mW / cm ² for 100 seconds, and the polyethylene terephthalate film as the base film was peeled off, whereby a thickness of 70 μm (the upper surface of the lower cladding layer) The upper cladding layer was formed with a distance between the upper cladding layer and the upper surface of the upper cladding layer.

[Examples 2-6, Comparative Examples 1-2]
An optical waveguide was formed in the same manner as in Example 1 except that the dry film was changed as shown in Table 3.

[4. Evaluation of optical waveguide]
The optical waveguides (Examples 1 to 6, Comparative Examples 1 and 2) were evaluated as follows.
(1) Accuracy of shape of optical waveguide When the height and width of the core part actually formed have dimensions of 50 ± 5 μm with respect to the designed core shape (height 50 μm × line width 50 μm) “○”, and “x” in other cases.
(2) Waveguide loss With respect to the optical waveguide, light having a wavelength of 850 nm was incident from one end. Then, by measuring the amount of light emitted from the other end, the waveguide loss per unit length was determined by the cutback method. A case where the waveguide loss was 0.5 dB / cm or less was rated as “◯”, and a case where the waveguide loss exceeded 0.5 dB / cm was rated as “x”.
(3) Bending resistance An optical waveguide manufactured such that the height of the lower cladding layer is 20 μm, the height of the core portion is 50 μm, and the height from the upper surface of the core portion to the upper surface of the upper cladding layer is 20 μm. A waveguide film having a width of 1 cm, a length of 10 cm, and a thickness of 90 μm was peeled from the substrate. When this waveguide film was wound around a metal rod having a radius of 2 mm under the conditions of a temperature of 23 ° C. and a humidity of 50%, the case where no crack or breakage occurred was indicated as “◯”, and the case where it occurred was indicated as “X”.

The results are shown in Table 3.

  From Table 3, the optical waveguide (Examples 1-6) formed using the dry film which has the layer which consists of a specific photosensitive resin composition of this invention has the high precision of the shape of a core part, and its optical characteristic is favorable. It can be seen that the waveguide loss is small and the bending resistance is excellent. On the other hand, an optical waveguide (Comparative Examples 1 and 2) formed by using a dry film having a layer made of a photosensitive resin composition not belonging to the present invention as a material of the entire optical waveguide or a clad layer is cracked or broken by bending. It turns out that it is inferior to bending resistance.

DESCRIPTION OF SYMBOLS 1 Dry film 2 Base film 3 Photosensitive resin composition layer 4 Cover film 10 Substrate 11 Dry film for lower layer 12 Base film 13 Photosensitive resin composition layer 14 Cover film 15 Light (ultraviolet)
16 Lower clad layer 21 Core dry film 22 Base film 23 Photosensitive resin composition layer 24 Cover film 25 Light (ultraviolet)
26 Photomask 27 Core portion 31 Upper layer dry film 32 Base film 33 Photosensitive resin composition layer 34 Cover film 35 Light (ultraviolet)
36 Upper cladding layer 37 Optical waveguide

Claims (11)

A dry film for forming an optical waveguide in which a base film and an uncured photosensitive resin composition layer are laminated,
The photosensitive resin composition layer has the following components (A) to (D):
(A) a polymer containing repeating units represented by the following general formulas (1) and (2),

Wherein R ¹ and R ² are each independently a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, R ³ is a (meth) acryloyl group, and X is a single bond or a divalent organic group. And Y is an organic group having no polymerizability.)
(B) a compound comprising a linear structure having a urethane bond repeatedly, which is generated by a reaction between an aliphatic polyether polyol and a polyisocyanate compound, and having 2 to 6 (meth) acryloyl groups,
(C) a compound having one or more ethylenically unsaturated groups in the molecule, and
(D) a photoradical polymerization initiator,
A dry film for forming an optical waveguide, which is a photosensitive resin composition containing The dry film for forming an optical waveguide according to claim 1 , wherein the general formula (1) has a structure represented by the following general formula (3).

Wherein R ¹ is a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, R ³ is a (meth) acryloyl group, and W and Z are each independently a single bond or a divalent organic group. .) The dry film for forming an optical waveguide according to claim 1 or 2 , wherein the number average molecular weight of the component (B) in terms of polystyrene measured by gel permeation chromatography is 1,000 to 100,000. The dry film for forming an optical waveguide according to any one of claims 1 to 3 , wherein the component (B) is a reaction product of an aliphatic polyether polyol , a polyisocyanate compound, and a hydroxyl group-containing (meth) acrylate. The dry film for forming an optical waveguide according to any one of claims 1 to 4 , wherein the photosensitive resin composition layer has a thickness of 1 to 200 µm. The dry film for forming an optical waveguide according to any one of claims 1 to 5 , wherein a cover film is laminated on a surface of the photosensitive resin composition layer opposite to the base film. 7. An optical waveguide including a lower cladding layer, a core portion, and an upper cladding layer, wherein at least the lower cladding layer and the upper cladding layer are dry for forming an optical waveguide according to claim 1. An optical waveguide comprising a cured product of a photosensitive resin composition layer of a film. 7. An optical waveguide including a lower cladding layer, a core portion, and an upper cladding layer, wherein at least one of the lower cladding layer, the core portion, and the upper cladding layer is any one of claims 1 to 6. (A) component which consists of a hardened | cured material of the photosensitive resin composition layer of the dry film for optical waveguide formation as described in this invention, and other than the part which consists of this hardened | cured material ~ An optical waveguide comprising a cured product of a liquid photosensitive resin composition containing a component (D). The said lower clad layer, core part, and upper clad layer consist of the hardened | cured material of the photosensitive resin composition layer of the dry film for optical waveguide formation of any one of Claims 1-6 , and the said core part The optical waveguide is characterized by having a refractive index of 0.1% or more greater than the refractive index of any of the lower cladding layer and the upper cladding layer. A method of manufacturing an optical waveguide including a lower clad layer, a core portion, and an upper clad layer, comprising: forming a lower clad layer; forming a core portion; and forming an upper clad layer The photosensitive resin composition of the dry film for forming an optical waveguide according to any one of claims 1 to 6 , wherein at least the step of forming the lower cladding layer and the step of forming the upper cladding layer include The manufacturing method of the optical waveguide characterized by including the process of light-irradiating and hardening | curing a layer. A method of manufacturing an optical waveguide including a lower cladding layer, a core portion, and an upper cladding layer,
Including a step of forming a lower clad layer, a step of forming a core portion, and a step of forming an upper clad layer,
At least one of the step of forming the lower clad layer, the step of forming the core portion, and the step of forming the upper clad layer is a dry for forming an optical waveguide according to any one of claims 1 to 6. Including a step of irradiating and curing the photosensitive resin composition layer of the film,
The step of forming a part other than the part to be cured by light irradiation of the photosensitive resin composition layer is a liquid photosensitive resin containing the same components (A) to (D) as the photosensitive resin composition layer. The manufacturing method of the optical waveguide characterized by including the process of irradiating and hardening a resin composition.

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