JP2009086058A - Photoelectric composite substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photoelectric composite substrate which has high adhesion between a polyimide film with metal wiring formed thereon and an optical waveguide. <P>SOLUTION: This photoelectric composite substrate 1 contains a film-like optical waveguide 4 containing a core portion 8 and cladding layers 7, 9, and the polyimide film 5 with the metal wiring 6 formed on one side. The film-like optical waveguide 4 and the polyimide film 5 are laminated through an adhesive layer 3 so that the surface on which the metal wiring 6 of the polyimide film 5 is formed may face at least one outer surface of the film-like optical waveguide 4. The adhesive layer 3 includes (A) a polyimide silicone resin which has a specific structure, (B) a compound containing at least two oxiranyl groups, and (D) a cured radiation curable composition containing a cationic photopolymerization initiator. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an opto-electric hybrid board.

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.
An optical waveguide is an interface for converting an electrical / optical signal by joining a light emitting element such as a photodiode and a light receiving element such as a surface emitting laser to one surface of the optical waveguide, and transmitting an optical signal transmitted from the light emitting element to the light receiving element. Used as a medium.

Here, in recent years, an opto-electric hybrid board has been proposed. For example, an optical waveguide core is sandwiched between electrical wiring layers stacked on the substrate, and an upper optical waveguide cladding having a lower refractive index than the optical waveguide core. And an optical-light mixed wiring board formed by laminating an optical waveguide provided with a lower optical waveguide cladding, a groove having a side wall perpendicular to the light propagation direction in front of the end of the optical waveguide, and a bottom surface of the groove, And a first conductor formed in parallel with the optical waveguide, a solder layer formed on the first conductor and in parallel with the first conductor, the first conductor and the substrate. There has been proposed an electric / light mixed wiring board including a columnar conductor to be connected (Patent Document 1). Patent Document 1 describes that the electrical wiring layer is a copper-polyimide multilayer wiring, and the optical waveguide is a polymer optical waveguide.
JP 2001-083346 A

However, the technique of Patent Document 1 has a problem that the adhesiveness between the electric wiring layer (copper polyimide multilayer wiring) and the optical waveguide (polymer optical waveguide) is low.
Then, an object of this invention is to provide the opto-electric hybrid board | substrate with high adhesiveness with the polyimide film in which metal wiring was formed, and an optical waveguide.

  As a result of intensive studies to solve the above-mentioned problems, the present inventor, as a result, is an adhesive made of a cured product of a radiation curable composition having a specific component composition between a polyimide film on which metal wiring is formed and an optical waveguide. It has been found that the above object of the present invention can be achieved by providing an agent layer, and the present invention has been completed.

（式中、Ｘ^１及びＸ^２は、各々独立して、四価の有機基、Ｙは二価の有機基、Ｚはオルガノポリシロキサン構造を有する二価の有機基である。）、
［２］ 上記放射線硬化性組成物は、さらに、（Ｅ）分子内に、少なくとも1個の（メタ）アクリロイル基と、少なくとも1個のエポキシ基とを有する化合物を含む上記［１］に記載の光電気混載基板。
［３］ 上記放射線硬化性組成物は、さらに、（Ｆ）下記一般式（４）で表される構造を有する化合物を含む上記［１］又は［２］に記載の光電気混載基板。

（式中、Ｒ^１は重合性の炭素−炭素二重結合を有する有機基、Ｒ^２及びＲ^３は、各々独立して、炭素数１〜１０のアルキル基、炭素数１〜１０のハロゲン化アルキル基、炭素数７〜１１のアラルキル基、炭素数３〜２０の一価の脂環族基、又は炭素数６〜２０のアリール基を示す。）
［４］ 上記（Ｆ）成分が、下記（ａ）、（ｂ）及び（ｃ）からなる群から選ばれる１つ以上の成分からなる上記［１］〜［３］のいずれか１つに記載の光電気混載基板。
（ａ）分子内に重合性の炭素−炭素二重結合を少なくとも２個以上有し、かつ、上記一般式（４）で表される構造を有する化合物
（ｂ）分子内に重合性炭素−炭素二重結合を１個有し、かつ、下記一般式（５）又は（６）で表される化合物

（式中、Ｒ^４は重合性の炭素−炭素二重結合を有する有機基、Ｒ^５は炭素数１〜１０のアルキル基を示し、Ｒ^６及びＲ^７は、各々独立して、炭素数１〜１０のアルキル基、炭素数６〜２０の１価の脂環族基、又は炭素数６〜２０の１価のアリール基を示す。）

（式中、Ｒ^８は重合性の炭素−炭素二重結合を有する有機基、Ｒ^９は水素原子、炭素数１〜１０のアルキル基、炭素数３〜１０の脂環族基、炭素数６〜１０のアリール基又は炭素数７〜１１のアラルキル基を示し、Ｒ^１０及びＲ^１１は、各々独立して、炭素数１〜１０のアルキル基、炭素数１〜１０のハロゲン化アルキル基、炭素数３〜１０の脂環族基、炭素数６〜１０のアリール基又は炭素数７〜１１のアラルキル基を示すか、あるいは、Ｒ^９、Ｒ^１０及びＲ^１１のいずれか２つがお互いに結合して５〜７員環を形成していてもよい。）
（ｃ）上記化合物（ａ）に由来する構成単位及び／又は上記化合物（ｂ）に由来する構成単位を含む（共）重合体
［５］ 上記放射線硬化性組成物は、さらに、（Ｇ）ラジカル性光重合開始剤を含む上記［１］〜［４］のいずれか1つに記載の光電気混載基板。
［６］ 上記フィルム状光導波路は、上記金属配線が形成されたポリイミドフィルムを有する側と反対側の外表面に、金属配線を有さないポリイミドフィルムを有する上記［１］〜［５］のいずれか１つに記載の光電気混載基板。 That is, the present invention provides the following [1] to [6].
[1] An opto-electric hybrid board including a film-shaped optical waveguide including a core portion and a cladding layer, and a polyimide film on which metal wiring is formed, wherein the film-shaped optical waveguide and the polyimide film are the polyimide The film is laminated through an adhesive layer so that the surface on which the metal wiring is formed faces at least one outer surface of the film-shaped optical waveguide, and the adhesive layer is the following (A) to (D (2) An opto-electric hybrid board comprising a cured product of a radiation curable composition containing a component.
(A) Polyimide silicone resin containing a structural unit represented by the following general formula (1) and a structural unit represented by the following general formula (2) (B) Compound containing two or more oxiranyl groups (C) Oxetanyl Compound (D) Cationic Photopolymerization Initiator Containing Two or More Groups

(Wherein, X ¹ and X ² are each independently a tetravalent organic group, Y is a divalent organic group, and Z is a divalent organic group having an organopolysiloxane structure).
[2] The radiation curable composition further includes (E) a compound having at least one (meth) acryloyl group and at least one epoxy group in the molecule. Opto-electric hybrid board.
[3] The opto-electric hybrid board according to [1] or [2], wherein the radiation curable composition further includes (F) a compound having a structure represented by the following general formula (4).

(Wherein R ¹ is an organic group having a polymerizable carbon-carbon double bond, R ² and R ³ are each independently an alkyl group having 1 to 10 carbon atoms or a halogenated group having 1 to 10 carbon atoms. An alkyl group, an aralkyl group having 7 to 11 carbon atoms, a monovalent alicyclic group having 3 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms.)
[4] The component (F) described in any one of the items [1] to [3], which includes one or more components selected from the group consisting of the following (a), (b), and (c). The opto-electric hybrid board.
(A) Compound having at least two polymerizable carbon-carbon double bonds in the molecule and having a structure represented by the general formula (4) (b) Polymerizable carbon-carbon in the molecule A compound having one double bond and represented by the following general formula (5) or (6)

(In the formula, R ⁴ represents an organic group having a polymerizable carbon-carbon double bond, R ⁵ represents an alkyl group having 1 to 10 carbon atoms, and R ⁶ and R ⁷ each independently represents 1 carbon atom. An alkyl group having 10 to 10 carbon atoms, a monovalent alicyclic group having 6 to 20 carbon atoms, or a monovalent aryl group having 6 to 20 carbon atoms.)

(In the formula, R ⁸ is an organic group having a polymerizable carbon-carbon double bond, R ⁹ is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alicyclic group having 3 to 10 carbon atoms, or 6 carbon atoms. Represents an aryl group having 10 to 10 carbon atoms or an aralkyl group having 7 to 11 carbon atoms, and R ¹⁰ and R ¹¹ are each independently an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group having 1 to 10 carbon atoms, carbon Represents an alicyclic group having 3 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms or an aralkyl group having 7 to 11 carbon atoms, or any two of R ⁹ , R ¹⁰ and R ¹¹ are bonded to each other. And may form a 5- to 7-membered ring.)
(C) A (co) polymer [5] containing a structural unit derived from the compound (a) and / or a structural unit derived from the compound (b) [5] The radiation curable composition further comprises (G) radical The opto-electric hybrid board according to any one of the above [1] to [4], which contains a photopolymerization initiator.
[6] Any of the above [1] to [5], wherein the film-shaped optical waveguide has a polyimide film having no metal wiring on the outer surface opposite to the side having the polyimide film on which the metal wiring is formed. The opto-electric hybrid board according to claim 1.

The opto-electric hybrid board of the present invention includes an adhesive layer made of a cured product of a radiation curable composition containing a specific component between the film-like optical waveguide and the polyimide film on which the metal wiring is formed. The adhesion between the polyimide film on which the metal wiring is formed and the film-like optical waveguide is excellent.
That is, the adhesive layer is in contact with both the metal wiring and the polyimide film at the interface with the polyimide film on which the metal wiring is formed, and has excellent adhesion to both of them. Yes. The adhesive layer also has excellent adhesion to a film-like optical waveguide (for example, the lower cladding layer). Therefore, the polyimide film on which the metal wiring is formed and the film-like optical waveguide can be firmly bonded via the adhesive layer. Therefore, the polyimide film on which the metal wiring is formed and the film-like optical waveguide are not peeled off, and the performance of the opto-electric hybrid board can be stably maintained for a long time.
The opto-electric hybrid board according to the present invention includes a film-shaped optical waveguide and a polyimide film on which metal wiring is formed, at least one outer surface of the film-shaped optical waveguide, and metal wiring of the polyimide film. Since it can be produced by laminating via a radiation curable composition and curing the radiation curable composition by radiation, the production equipment and the production process are simple. Low cost.

The opto-electric hybrid board of the present invention includes a film-shaped optical waveguide including a core portion and a clad layer, a polyimide film on which metal wiring is formed, and the film-shaped optical waveguide and the polyimide film are Laminated via an adhesive layer made of a cured product of a radiation curable composition containing a specific component so that the surface on which the metal wiring of the polyimide film is formed faces at least one outer surface of the film-shaped optical waveguide. It has been made.
First, the radiation curable composition for adhesive layers will be described in detail.
The radiation-curable composition for the adhesive layer includes the components (A) to (D) and other optional components that are added as necessary.
Here, the total amount of the radiation curable composition for the adhesive layer is the total amount including the components (A) to (D) and other optional components added as necessary (however, an organic solvent) The total amount excluding the organic solvent).

[(A) component]
(A) component used for the radiation-curable composition for adhesive layers is a polyimide silicone resin containing a structural unit represented by the following general formula (1) and a structural unit represented by the following general formula (2) It is. By including the component (A), it is possible to increase the adhesiveness between the adhesive layer formed by curing the radiation curable composition, and each of the film-shaped optical waveguide, the metal wiring, and the polyimide film. The optical waveguide and the polyimide film on which the metal wiring is formed can be firmly bonded.

（式中、Ｘ^１及びＸ^２は、各々独立して、四価の有機基、Ｙは二価の有機基、Ｚはオルガノポリシロキサン構造を有する二価の有機基である。）、

(Wherein, X ¹ and X ² are each independently a tetravalent organic group, Y is a divalent organic group, and Z is a divalent organic group having an organopolysiloxane structure).

In the general formula (1), X ¹ and X ² are each independently a tetravalent organic group such as 4,4′-oxydiphthalic dianhydride (orthodiphenylphthalic dianhydride), 3 , 3 ′, 4,4′-diphenylsulfonetetracarboxylic dianhydride, 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride, 3,3 ′, 4,4′-dimethyldiphenylsilanetetra To acid dianhydrides such as carboxylic dianhydride, 3,3 ′, 4,4′-tetraphenyltetracarboxylic dianhydride, 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride The tetravalent organic group which originates is mentioned. Of these, tetravalent organic groups derived from 4,4′-oxydiphthalic dianhydride and 3,3 ′, 4,4′-diphenylsulfone tetracarboxylic dianhydride are preferred.
Y includes p-phenylenediamine, m-phenylenediamine, 3,3′-dimethyl-4,4′-diaminobiphenyl, 3,3′-dimethoxy-4,4′-diaminobiphenyl, 1,5-diaminonaphthalene 9,9-bis (4-aminophenyl) -10-hydroanthracene, 4,4 ′-(p-phenyleneisopropylidene) bisaniline, 4,4 ′-(m-phenyleneisopropylidene) bisaniline, 5-amino- 1- (4′-aminophenyl) -1,3,3-trimethylindane, 6-amino-1- (4′-aminophenyl) -1,3,3-trimethylindane, 2,7-diaminofluorene, 9 , 9-bis (4-aminophenyl) fluorene, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylethane, 4,4'-diamino Phenyl sulfide, 4,4′-diaminodiphenyl sulfone, 4,4′-diaminobenzanilide, 4,4′-diaminodiphenyl ether, 3,4′-diaminodiphenyl ether, 3,3′-diaminobenzophenone, 3,4′- Diaminobenzophenone, 4,4′-diaminobenzophenone, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] sulfone, 1,4 -Bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 4,4 '-(p-biphenylenedioxy) dianiline, etc. And divalent organic groups derived from the diamine. Of these, divalent organic groups derived from 2,2-bis [4- (4-aminophenoxy) phenyl] propane are preferred.
Z is a divalent organic group having an organopolysiloxane group, and examples thereof include a divalent group represented by the following general formula (3). The divalent group represented by the general formula (3) is a divalent residue excluding the amino group of diaminoorganopolysiloxane.

（式中、Ｒ^１及びＲ^２は、各々独立して、２価の炭化水素基又はフェニレン基であり、Ｒ^３〜Ｒ^６は、各々独立して、炭素数１〜５のアルキル基又はフェニル基であり、ｒは２〜３０の整数である。）

(In the formula, R ¹ and R ² are each independently a divalent hydrocarbon group or a phenylene group, and R ^{3 to} R ⁶ are each independently an alkyl group having 1 to 5 carbon atoms or phenyl. And r is an integer of 2 to 30.)

In General Formula (3), R ¹ and R ² are each independently a divalent hydrocarbon group or a phenylene group, preferably a C 1-5 divalent alkylene group.
In general formula (3), R < ³ > -R < ⁶ > is respectively independently a C1-C5 alkyl group or a phenyl group, Preferably it is a methyl group.
In general formula (3), r is an integer of 2-30, Preferably it is an integer of 3-20.

  The proportion of the structural unit represented by the general formula (1) and the structural unit represented by the general formula (2) is the ratio of the structural unit represented by the general formula (1) to 100 mol% in total. It is preferably 10 mol% to 90 mol%, more preferably 20 mol% to 80 mol%, and the structural unit represented by the general formula (2) is preferably 10 mol% to 90 mol%, more preferably 20 mol%. Mol% to 80 mol%.

The polyimide silicone resin containing the structural unit represented by the general formula (1) and the structural unit represented by the general formula (2) is, for example, 4,4′-oxydiphthalic dianhydride, 3,3 ′, 4. , 4′-diphenylsulfonetetracarboxylic dianhydride and the like, a diamine such as 2,2-bis [4- (4-aminophenoxy) phenyl] propane, and a diaminoorganopolysiloxane are reacted. Can be obtained.
The weight average molecular weight of the polyimide silicone resin is preferably 5,000 to 100,000, more preferably 10,000 to 70,000.

  Examples of the commercially available polyimide silicone resin used as the component (A) include SMP2006 (manufactured by Shin-Etsu Chemical Co., Ltd.).

  In the radiation curable composition for the adhesive layer, the blending ratio of the component (A) is preferably 40 to 80% by mass, more preferably 40 to 70% by mass, with the total amount of the radiation curable composition being 100% by mass. It is. When the blending ratio is less than 40% by mass, the adhesiveness between the adhesive layer formed by curing the radiation curable composition and the film-shaped optical waveguide, metal wiring, or polyimide film is lowered, and the film-shaped optical waveguide And the adhesion with the polyimide film on which the metal wiring is formed may be unfavorable. On the other hand, when the blending ratio exceeds 80% by mass, the blending ratio of the other components decreases accordingly, the curing rate of the composition decreases, and a cured product (adhesive layer) having sufficient mechanical strength is obtained. Since it may become difficult to form, it is not preferable.

[Component (B)]
The component (B) used in the radiation curable composition for the adhesive layer is a compound containing two or more oxiranyl groups in the molecule (particularly, a compound not containing a (meth) acryloyl group).
Examples of the component (B) include bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, bisphenol S diglycidyl ether, brominated bisphenol A diglycidyl ether, brominated bisphenol F diglycidyl ether, brominated bisphenol S diglycidyl ether. Bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, epoxy novolac resin, hydrogenated bisphenol A diglycidyl ether, hydrogenated bisphenol F diglycidyl ether, hydrogenated bisphenol S diglycidyl ether, 3, 4 —Epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate, ε-caprolactone modified 3,4-epoxycyclohexylmethyl— 3 ′, 4′-epoxycyclohexanecarboxylate, trimethylcaprolactone modified 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate, β-methyl-δ-valerolactone modified 3,4-epoxycyclohexylmethyl- 3 ′, 4′-epoxycyclohexanecarboxylate, 2- (3,4-epoxycyclohexyl-5,5-spiro-3,4-epoxy) cyclohexane-meta-dioxane, bis (3,4-epoxycyclohexylmethyl) adipate And neopentyl glycol diglycidyl ether.
Among these, bisphenol A type epoxy resin is preferable.

  Examples of the commercially available component (B) include JER828, JER834 (manufactured by Japan Epoxy Resin Co., Ltd.), KRM2110 (Asahi Denka Kogyo Co., Ltd.), SR-NPG (manufactured by Sakamoto Pharmaceutical Co., Ltd.), and the like.

  In the radiation curable composition for the adhesive layer, the blending ratio of the component (B) is preferably 1 to 40% by mass, more preferably 10 to 30% by mass, with the total amount of the radiation curable composition being 100% by mass. It is. When the blending ratio is less than 1% by mass, the adhesiveness between the adhesive layer formed by curing the radiation curable composition and the polyimide film on which the metal wiring is formed is lowered. This is not preferable because the adhesiveness between the waveguide and the polyimide film on which the metal wiring is formed may be lowered. On the other hand, if the blending ratio exceeds 40% by mass, the curing rate of the composition decreases, and it may be difficult to form a cured product (adhesive layer) having sufficient mechanical strength. .

[Component (C)]
The component (C) used in the radiation curable composition for the adhesive layer is a compound containing two or more oxetanyl groups in the molecule (particularly, a compound that does not contain a (meth) acryloyl group).
Examples of the component (C) include xylylene oxetane, bis (3-ethyl-3-oxetanylmethyl) ether, 1,4-bis {[(3-ethyl-3-oxetanyl) methoxy] methyl} benzene, 1, 3-bis {(1-ethyl-3-oxetanyl) methoxy} benzene and the like.
Among these, xylylene oxetane is preferable.

  (C) As a commercial item of a component, XDO (made by Toagosei Co., Ltd.) etc. are mentioned.

  In the radiation curable composition for the adhesive layer, the blending ratio of the component (C) is preferably 1 to 30% by mass, more preferably 1 to 20% by mass, with the total amount of the radiation curable composition being 100% by mass. It is. If the blending ratio is less than 1% by mass, the curing rate of the composition decreases, and it may be difficult to form a cured product (adhesive layer) having sufficient mechanical strength. On the other hand, when the blending ratio exceeds 30% by mass, the adhesiveness between the adhesive layer formed by curing the radiation curable composition and the film-shaped optical waveguide is lowered. As a result, the film-shaped optical waveguide and the metal wiring are reduced. Since the adhesiveness with the polyimide film formed with may be lowered, it is not preferable.

[(D) component]
(D) component used for the radiation-curable composition for adhesive bond layers is a cationic photoinitiator. The cationic photopolymerization initiator is a compound that can release a substance that initiates cationic polymerization of the component (B) and the component (C) by receiving energy rays such as light. Here, energy rays such as light mean visible light, ultraviolet light, infrared light, X-rays, α rays, β rays, γ rays and the like.
Preferable examples of the cationic photopolymerization initiator include onium salts having a structure represented by the following general formula (7).
_{^{[R 1 a R 2 b R}} 3 c R 4 d W] + m [MX n + m] -m (7)
(Wherein the cation is an onium ion, W is S, Se, Te, P, As, Sb, Bi, O, I, Br, Cl, or —N═N, and R ¹ , R ² , R ³ And R ⁴ are the same or different organic groups, a, b, c and d are each an integer of 0 to 3, and (a + b + c + dm) is equal to the valence of W. M is a halide complex [ MX _{n + m} ] is a metal or metalloid constituting the central atom of, for example, B, P, As, Sb, Fe, Sn, Bi, Al, Ca, In, Ti, Zn, Sc, V, Cr, Mn, Co, etc. X is a halogen atom such as F, Cl, Br, etc., m is the net charge of the halide complex ion, and n is the valence of M.)
The onium salt represented by the general formula (7) is a compound that releases a Lewis acid by receiving light. Specific examples of the anion [MX _{n + m} ] in the general formula (7) include tetrafluoroborate (BF ₄ ⁻ ), hexafluorophosphate (PF ₆ ⁻ ), hexafluoroantimonate (SbF ₆ ⁻ ), hexafluoroarsenate. (AsF ₆ ⁻ ), hexachloroantimonate (SbCl ₆ ⁻ ) and the like.
Moreover, the onium salt which has an anion represented with general formula [MXn (OH) _< ^- >] can be used. Furthermore, perchlorate ion (ClO ₄ ⁻ ), trifluoromethane sulfonate ion (CF ₃ SO ₃ ⁻ ), fluorosulfonate ion (FSO ₃ ⁻ ), toluene sulfonate ion, trinitrobenzene sulfonate anion, trinitrotoluene sulfonate Onium salts having other anions such as anions can also be used.

  Among such onium salts, aromatic onium salts are particularly effective as the component (D). Of these, aromatic halonium salts described in JP-A-50-151996, JP-A-50-158680, JP-A-50-151997, JP-A-52-30899, JP-A-56. Group VIA aromatic onium salts described in JP-A-55420, JP-A-55-125105, etc., Group VA aromatic onium salts described in JP-A-50-158698, etc., JP-A-56-8428 Oxosulfoxonium salts described in JP-A-56-149402 and JP-A-57-192429, aromatic diazonium salts described in JP-A-49-17040, US Pat. , 139,655 specification, and the like. Moreover, an iron / allene complex, an aluminum complex / photolytic silicon compound-based initiator, and the like can also be mentioned.

  Commercially available cationic photopolymerization initiators that can be suitably used as the component (D) include UVI-6950, UVI-6970, UVI-6974, UVI-6990 (manufactured by Union Carbide), Adekaoptomer SP- 150, SP-151, SP-170, SP-172 (above, manufactured by ADEKA), Irgacure 261 (above, manufactured by Ciba Specialty Chemicals), CI-2481, CI-2624, CI-2639, CI-2064 (above Manufactured by Nippon Soda Co., Ltd.), CD-1010, CD-1011, CD-1012 (above, manufactured by Sartomer), DTS-102, DTS-103, NAT-103, NDS-103, TPS-103, MDS-103, MPI-103, BBI-103 (above, manufactured by Midori Chemical Co., Ltd.), PCI-061T PCI-062T, PCI-020T, PCI-022T (manufactured by Nippon Kayaku Co.), CPI-100A, CPI-110A, K-1 (manufactured by SAN-APRO Ltd.), and the like. Among these, UVI-6970, UVI-6974, Adekaoptomer SP-170, SP-172, CD-1012, and MPI-103 can exhibit high photocuring sensitivity in the composition containing them. This is particularly preferable because it can be performed. Said cationic photoinitiator can comprise (D) component individually by 1 type or in combination of 2 or more types.

  In the radiation curable composition for the adhesive layer, the blending ratio of the component (D) is preferably 0.1 to 10% by mass, more preferably 1 to 8%, with the total amount of the radiation curable composition being 100% by mass. % By mass. If the blending ratio is less than 0.1% by mass, the photocurability of the composition is lowered, which is not preferable. On the other hand, if the blending ratio exceeds 10% by mass, it is not preferable because sufficient light transmission cannot be obtained when the composition is cured by radiation, and defective curing occurs.

[Component (E)]
The radiation-curable composition for the adhesive layer contains a compound ((E) component) having at least one (meth) acryloyl group and at least one epoxy group in the molecule, if necessary. be able to.
Examples of the compound that can be used as the component (E) include 3,4-epoxycyclohexylmethyl (meth) acrylate, glycidyl (meth) acrylate, and the like.
Examples of these commercially available products include Cycler M100 and Cycler A400 (manufactured by Daicel Chemical Industries, Ltd.).
In the radiation curable composition for the adhesive layer, the blending ratio of the component (E) is preferably 1 to 10% by mass with the total amount of the radiation curable composition being 100% by mass. By making the said mixture ratio 1 mass% or more, the adhesiveness of the adhesive bond layer formed by hardening | curing a radiation-curable composition and a film-form optical waveguide can further be improved. When the blending ratio exceeds 10% by mass, the curing rate of the composition is lowered, and a cured product (adhesive layer) having sufficient mechanical strength tends to be not obtained, which is not preferable.

[(F) component]
The radiation curable composition for an adhesive layer can contain a component ((F) component) that dissociates in the presence of an acid to generate a carboxyl group, if necessary.
Component (F) (component that dissociates in the presence of an acid to generate a carboxyl group) is a compound having a structure represented by the following general formula (4). The acid is usually supplied as an acid generated by (D) cationic photopolymerization initiator being decomposed by light irradiation.

（式中、Ｒ^１は重合性の炭素−炭素二重結合を有する有機基、Ｒ^２及びＲ^３は、各々独立して、炭素数１〜１０のアルキル基、炭素数１〜１０のハロゲン化アルキル基、炭素数７〜１１のアラルキル基、炭素数３〜２０の一価の脂環族基、又は炭素数６〜２０のアリール基を示す。）

(Wherein R ¹ is an organic group having a polymerizable carbon-carbon double bond, R ² and R ³ are each independently an alkyl group having 1 to 10 carbon atoms or a halogenated group having 1 to 10 carbon atoms. An alkyl group, an aralkyl group having 7 to 11 carbon atoms, a monovalent alicyclic group having 3 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms.)

In General Formula (4), R ² and R ³ are each independently an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group having 1 to 10 carbon atoms, an aralkyl group having 7 to 11 carbon atoms, or a carbon number. A 3-20 monovalent alicyclic group or a C6-C20 aryl group is shown. The alkyl group having 1 to 10 carbon atoms may be linear or branched. For example, a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, i-butyl group, sec-butyl group, t-butyl group, n-pentyl group, neopentyl group, n-hexyl group, n-heptyl group, n-octyl group, 2-ethylhexyl group, n-nonyl group, n- A decyl group etc. are mentioned. As the halogenated alkyl group having 1 to 10 carbon atoms of R ² and R ^3, for example, mention may be made of trifluoroethyl group, hexafluoro propyl group, a heptadecafluorooctyl deci group. As the aralkyl group of R ² and carbon atoms of R ³ 7 to 11, and examples thereof include a benzyl group, alpha-methylbenzyl group, a phenethyl group, a naphthylmethyl group. In the general formula (4), examples of the monovalent alicyclic group having 3 to 20 carbon atoms of R ² and R ³ include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, Cyclooctyl group, 2-methylcyclohexyl group, 3-methylcyclohexyl group, 4-methylcyclohexyl group, 4-chlorocyclohexyl group, 4-t-butylcyclohexyl group, norbornyl group, isobornyl group, adamantyl group, 2-methyladamantyl group And a tricyclodecanyl group. Examples of the aryl group having 6 to 20 carbon atoms include phenyl group, o-tolyl group, m-tolyl group, p-tolyl group, 4-chlorophenyl group, 4-t-butylphenyl group, and 1-naphthyl group. And benzyl group.

Specific examples of the compound (compound having a structure represented by the general formula (4)) include, for example, the following compound (a), compound (b), (co) polymer (c) and the like. it can.
The compound (a), the compound (b), and the (co) polymer (c) may constitute the component (F) alone or in combination of two or more.
(Compound (a))
The compound (a) is a compound having at least two polymerizable carbon-carbon double bonds in the molecule and having a structure represented by the general formula (4).
Specific examples of the compound (a) include 2,5-dimethylhexane-2,5-di (meth) acrylate, 1,3-di (2-hydroxypropyl) benzene-di (meth) acrylate and the like.
Compound (a) is synthesized, for example, by esterifying a polyhydric alcohol having at least one tertiary hydroxyl group and a monovalent carboxylic acid having one polymerizable carbon-carbon double bond. Can do. Examples of the esterification reaction include (1) an acid chloride method in which an acid chloride of the carboxylic acid compound is reacted with the polyhydric alcohol, and (2) a condensing agent such as dicyclohexylcarbodiimide. A method of reacting an acid compound, (3) a method of reacting the polyhydric alcohol with the carboxylic acid compound using a strong acid anhydride such as trifluoroacetic anhydride as a dehydrating agent, and (4) the polyhydric alcohol The transesterification with an ester of the carboxylic acid compound can be carried out.

(Compound (b))
The compound (b) is a compound having one polymerizable carbon-carbon double bond and represented by the following structural formula (5) or (6).

（式中、Ｒ^４は重合性の炭素−炭素二重結合を有する有機基、Ｒ^５は炭素数１〜１０のアルキル基を示し、Ｒ^６及びＲ^７は、各々独立して、炭素数１〜１０のアルキル基、炭素数６〜２０の１価の脂環族基、又は炭素数６〜２０の１価のアリール基を示す。）

(In the formula, R ⁴ represents an organic group having a polymerizable carbon-carbon double bond, R ⁵ represents an alkyl group having 1 to 10 carbon atoms, and R ⁶ and R ⁷ each independently represents 1 carbon atom. An alkyl group having 10 to 10 carbon atoms, a monovalent alicyclic group having 6 to 20 carbon atoms, or a monovalent aryl group having 6 to 20 carbon atoms.)

（式中、Ｒ^８は重合性の炭素−炭素二重結合を有する有機基、Ｒ^９は水素原子、炭素数１〜１０のアルキル基、炭素数３〜１０の脂環族基、炭素数６〜１０のアリール基、又は炭素数７〜１１のアラルキル基を示し、Ｒ^１０及びＲ^１１は、各々独立して、炭素数１〜１０のアルキル基、炭素数１〜１０のハロゲン化アルキル基、炭素数３〜１０の脂環族基、炭素数６〜１０のアリール基、又は炭素数７〜１１のアラルキル基を示すか、あるいは、Ｒ^９、Ｒ^１０及びＲ^１１のいずれか２つがお互いに結合して５〜７員環を形成していてもよい。）

(In the formula, R ⁸ is an organic group having a polymerizable carbon-carbon double bond, R ⁹ is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alicyclic group having 3 to 10 carbon atoms, or 6 carbon atoms. Represents an aryl group having 10 to 10 carbon atoms or an aralkyl group having 7 to 11 carbon atoms, and R ¹⁰ and R ¹¹ are each independently an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group having 1 to 10 carbon atoms, An alicyclic group having 3 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, or an aralkyl group having 7 to 11 carbon atoms, or any two of R ⁹ , R ¹⁰ and R ¹¹ are mutually And may form a 5- to 7-membered ring.)

In general formula (5), examples of the alkyl group having 1 to 10 carbon atoms of R ⁵ , R ⁶ , and R ⁷ include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, and an n-butyl group. I-butyl group, t-butyl group, sec-butyl group, n-pentyl group, neopentyl group, n-hexyl group, n-heptyl group, n-octyl group, 2-ethylhexyl group, n-nonyl group, n -A decyl group etc. can be mentioned. In the general formula (5), examples of the monovalent alicyclic group having 6 to 20 carbon atoms of R ⁶ and R ⁷ include a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a 2-methylcyclohexyl group, List 3-methylcyclohexyl group, 4-methylcyclohexyl group, 4-chlorocyclohexyl group, 4-t-butylcyclohexyl group, norbornyl group, isobornyl group, adamantyl group, 2-methyladamantyl group, tricyclodecanyl group, etc. Can do. In the general formula (5), examples of the monovalent aryl group having 6 to 20 carbon atoms of R ⁶ and R ⁷ include a phenyl group, an o-tolyl group, an m-tolyl group, a p-tolyl group, 4 -Chlorophenyl group, 4-t-butylphenyl group, 1-naphthyl group, benzyl group and the like can be mentioned.

In General Formula (6), R ⁹ is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alicyclic group having 3 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, or 7 to 11 carbon atoms. Aralkyl group. The alkyl group having 1 to 10 carbon atoms of R ⁹ may be linear or branched, for example, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl. Group, i-butyl group, sec-butyl group, t-butyl group, n-pentyl group, neopentyl group, n-hexyl group, n-heptyl group, n-octyl group, 2-ethylhexyl group, n-nonyl group, An n-decyl group etc. can be mentioned. Examples of the monovalent alicyclic group having 3 to 10 carbon atoms of R ⁹ include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a norbornyl group, and an isobornyl group. Can be mentioned. Examples of the monovalent aryl group having 6 to 10 carbon atoms of R ⁹ include a phenyl group, an o-tolyl group, an m-tolyl group, a p-tolyl group, a xylyl group, a cumenyl group, and a 1-naphthyl group. be able to. In addition, examples of the aralkyl group having 7 to 11 carbon atoms of R ⁹ include a benzyl group, an α-methylbenzyl group, a phenethyl group, and a naphthylmethyl group.
In General Formula (6), R ¹⁰ and R ¹¹ are each independently an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group having 1 to 10 carbon atoms, an alicyclic group having 3 to 10 carbon atoms, An aryl group having 6 to 10 carbon atoms or an aralkyl group having 7 to 11 carbon atoms. Of these, specific examples of the group other than the halogenated alkyl group include the same groups as those described above for R ⁹ . Examples of the halogenated alkyl group include a trifluoroethyl group, a hexafluoropropyl group, a heptadecafluorodecyl group, and the like.
Moreover, in General formula (6), any two of R < ⁹ >, R < ¹⁰ > and R < ¹¹ > may combine with each other to form a 5- to 7-membered ring. Examples of the 5- to 7-membered ring when R ⁹ and R ¹¹ are bonded include a cyclopentyl group, a cyclohexyl group, and a cycloheptyl group. Examples of the 5- to 7-membered ring in the case where R ⁹ and R ¹⁰ or R ¹⁰ and R ¹¹ are bonded include a tetrahydrofuranyl group and a tetrahydropyranyl group.

  Specific examples of the monovalent carboxylic acid having one polymerizable carbon-carbon double bond constituting the compound (b) having the structure represented by the general formula (5) or (6) include the above structural formula The same thing as (4) can be mentioned.

  Specific examples of the compound (b) include, for example, t-butyl (meth) acrylate, tetrahydropyranyl (meth) acrylate, 2-t-butoxycarbonylmethyl (meth) acrylate, and 2-benzyloxycarbonylethyl (meth) acrylate. 2-methyladamantyl (meth) acrylate, 1,1-dimethyl-3-oxobutyl (meth) acrylate, 2-benzylpropyl (meth) acrylate, and the like.

((Co) polymer (c))
The (co) polymer (c) is a (co) polymer containing a structural unit derived from the compound (a) and / or a structural unit derived from the compound (b). Moreover, the (co) polymer (c) can contain the structural unit derived from other copolymerization monomers other than a compound (a) and (b) as needed.
In the (co) polymer (c), the content of the structural unit derived from the compound (b) is not particularly limited as long as the effect of the present invention is not impaired, but is usually 10 to 100 mol%. , Preferably 20 to 100 mol%, more preferably 30 to 100 mol%. If the said content rate is less than 10 mol%, the impact resistance of the adhesive bond layer formed by hardening | curing a radiation-curable composition will fall.
In addition, the compound (a) reduces the mobility of the polymer molecular chain by introducing an appropriate branched structure into the (co) polymer (c), thereby improving the initial mechanical and thermal characteristics of the cured product. It has the function of improving and lowering the molecular weight by the action of acid. In the (co) polymer (c), the content of the structural unit derived from the compound (a) is usually 0 to 40 mol%, preferably 0 to 30 mol%, more preferably 0 to 25 mol%. When the content is 40 mol% or more, the solubility of the (co) polymer (c) in the radiation curable composition is lowered, and a uniform composition cannot be obtained.

  Examples of the other copolymerizable monomers include aromatic vinyl compounds such as styrene, α-methylstyrene, p-methylstyrene, p-chlorostyrene, and p-methoxystyrene; N-vinylpyrrolidone, N-vinylcaprolactam, and the like. Heteroatom-containing alicyclic vinyl compounds; cyano group-containing vinyl compounds such as (meth) acrylonitrile and vinylidene cyanide; (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-dimethylol (meth) acrylamide (Meth) acrylamide (derivatives) such as methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, i-propyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2- Hydroxypropyl (meth) acrelane , Nonpolar (meth) acrylates such as phenyl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, isobornyl (meth) acrylate, tricyclodecanyl (meth) acrylate; (meth) acrylic acid, croton Carboxyl group-containing (meth) acrylates such as acid, cinnamic acid, maleic acid, fumaric acid, itaconic acid, 2- (meth) acryloyloxyethylcarboxylic acid, 4- (meth) acryloyloxycyclohexylcarboxylic acid; o Examples include phenolic hydroxyl group-containing aromatic vinyl compounds such as -hydroxystyrene, m-hydroxystyrene, p-hydroxystyrene, o-isopropenylphenol, m-isopropenylphenol, and p-isopropenylphenol. These monomers can be used individually or in mixture of 2 or more types.

The (co) polymer (c) is prepared by a known method using a polymerization initiator, a molecular weight modifier, etc., with the compound (a) and / or the compound (b) and, if necessary, other copolymerizable monomers. Can be obtained by (co) polymerizing Moreover, a compound (a), a compound (b), and another copolymerizable monomer can each be used individually by 1 type or in combination of 2 or more types.
Examples of the polymerization initiator include benzoyl peroxide, lauroyl peroxide, 2,2′-azobisisobutyronitrile, 4,4′-azobis (4-cyanovaleric acid), 2,2′-azobis ( 4-methoxy-2,4-dimethylvaleronitrile) and the like. These polymerization initiators can be used alone or in admixture of two or more.
Examples of the molecular weight modifier include halogenated hydrocarbons such as carbon tetrachloride, chloroform, carbon tetrabromide; n-hexyl mercaptan, n-octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, thioglycolic acid And mercaptans such as thiopropionic acid; xanthogens such as dimethylxanthogen disulfide and diisopropylxanthogen disulfide; terpinolene and α-methylstyrene dimer. These molecular weight modifiers can be used alone or in admixture of two or more.

  The polystyrene equivalent weight average molecular weight (hereinafter referred to as "Mw") of the (co) polymer (c) by gel permeation chromatography (GPC) is usually 1,000 to 500,000, preferably 5,000 to 200. 1,000, more preferably 10,000 to 150,000. When the Mw of the (co) polymer (c) is less than 1,000, the mechanical and thermal properties of the adhesive layer formed by curing the radiation curable composition tend to be lowered. On the other hand, when the Mw of the (co) polymer (c) exceeds 500,000, the solubility of the (co) polymer (c) in the radiation curable composition is lowered, and a uniform composition cannot be obtained. Tend.

Specific examples of the (co) polymer (c) include a copolymer of p-isopropenylphenol and t-butyl acrylate, a copolymer of styrene and 2-benzylpropyl (meth) acrylate, and the like.
In addition, (co) polymer (c) can be used individually or in mixture of 2 or more types.

In the radiation curable composition for the adhesive layer, the blending ratio of the component (F) is preferably 1 to 25% by mass, more preferably 5 to 25% by mass, with the total amount of the radiation curable composition being 100% by mass. It is. When the said mixture ratio is 1 mass% or more, the adhesiveness of the adhesive bond layer and metal wiring which harden a radiation-curable composition can be improved. When the blending ratio exceeds 25% by mass, the mechanical strength of the cured product (adhesive layer) is reduced or the curing shrinkage is increased. Tend to happen.
In the component (F), the compound (a), the compound (b), and the (co) polymer (c) can be used alone or in admixture of two or more.

[(G) component]
The radiation-curable composition for the adhesive layer can contain a radical photopolymerization initiator ((G) component) as necessary. The radical photopolymerization initiator is a photopolymerization initiator that can generate an active species (radical) by light. 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 radical photopolymerization 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, die Ruthioxanthone, 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. Among these, 1-hydroxycyclohexyl phenyl ketone and the like are preferably used from the viewpoints of polymerization rate and solution stability.
Examples of commercially available products of component (G) include Irgacure 184, 369, 379, 651, 500, 819, 907, 784, 2959, CGI-1700, -1750, -1850, CG24-61, Darocur 1116, 1173 (above Ciba Specialty Chemicals); Lucirin TPO, LR8883, LR8970 (above, manufactured by BASF); Ubekrill P36 (UCB), and the like.
A radical photoinitiator is used individually by 1 type or in combination of 2 or more types.

  Moreover, a photosensitizer can be used with a radical photoinitiator. Examples of the photosensitizer include triethylamine, diethylamine, N-methyldiethanolamine, ethanolamine, 4-dimethylaminobenzoic acid, methyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate, and 4-dimethylaminobenzoic acid. Isoamyl etc. are mentioned. Examples of commercially available photosensitizers include Ubekryl P102, 103, 104, and 105 (above, manufactured by UCB).

  In the radiation curable composition for the adhesive layer, the blending ratio of the component (G) is preferably 0.1 to 10% by mass, more preferably 0.2%, with the total amount of the radiation curable composition being 100% by mass. -7% by mass, more preferably 0.5-5% by mass. By making the said mixture ratio 0.1 mass% or more, the radiation curability of a composition can be improved more and the mechanical strength of hardened | cured material (adhesive layer) can further be raised. When the said mixture ratio exceeds 10 mass%, an excess amount of radical photoinitiator may have a bad influence on the long-term characteristic of an adhesive bond layer.

Moreover, the radiation curable composition for adhesive layers can contain an organic solvent as needed. By blending an organic solvent, an appropriate viscosity can be imparted and an adhesive layer having a uniform thickness can be formed.
The type of the organic solvent can be appropriately selected within a range that does not impair the object and effect of the present invention, but has a boiling point within the range of 50 to 200 ° C. under atmospheric pressure, and each constituent component Those that dissolve uniformly are preferred.
Preferable examples of the organic solvent include alcohols, ethers, esters, and ketones. The preferred compound name of the organic solvent is at least one selected from the group consisting of propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, ethyl lactate, diethylene glycol dimethyl ether, methyl isobutyl ketone, methyl amyl ketone, toluene, xylene, and methanol. A solvent is mentioned.
The blending amount of the organic solvent is preferably 5 to 500 parts by mass, more preferably 10 to 300 parts by mass, and particularly preferably 20 to 200 parts by mass with respect to 100 parts by mass of the total amount of the components (A) to (G). Part. If the said compounding quantity is less than 5 mass parts, adjustment of the viscosity of a radiation-curable composition may become difficult. On the other hand, when the blending amount exceeds 500 parts by mass, it may be difficult to form an adhesive layer having a sufficient thickness.

The radiation curable composition for the adhesive layer may be, for example, a compound having a polymerizable reactive group other than components (A) to (C) or a polymer resin (for example, component (B), if necessary. 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, fluorine polymer, silicone polymer) and the like.
Furthermore, the radiation-curable composition for the adhesive layer can contain various additives as necessary. Various additives include, for example, antioxidants, ultraviolet absorbers, light stabilizers, silane coupling agents, coating surface improvers, thermal polymerization inhibitors, leveling agents, surfactants, colorants, storage stabilizers, plasticizers. Agents, lubricants, fillers, inorganic particles, anti-aging agents, wettability improvers, antistatic agents and the like.
The radiation curable composition is prepared by mixing and stirring the above components according to a conventional method.

（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）アクリロイルオキシ基であり、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。）
一般式（８）及び（９）中の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、好ましくは、水素原子又は炭素数１〜５のアルキル基であり、より好ましくは、水素原子又はメチル基である。 Next, materials for forming each part (core part, lower clad layer, upper clad layer) of the film-like optical waveguide of the opto-electric hybrid board of the present invention will be described.
Examples of the material for forming the film-like optical waveguide include a radiation curable composition, for example, one or more compounds selected from urethane (meth) acrylate oligomers and ethylenically unsaturated group-containing polymers, and reactive dilution. Examples thereof include a radiation curable composition containing a monomer and a photopolymerization initiator.
Specifically, as a suitable example of a radiation curable composition for forming an optical waveguide, at least one compound selected from (a) component and (b) component, (c) component, and (d) And a radiation curable composition containing a component.
[(I) component]
The component (a) used in the radiation curable composition for an optical waveguide is a polymer (for example, a random copolymer) containing repeating units represented by the following general formulas (8) and (9).

(In the formula, 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) acryloyloxy group, and X is a single bond or a divalent organic group. Y is an organic group having no polymerizability.)
R ¹ and R ² in the general formulas (8) and (9) 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. Group, more preferably a hydrogen atom or a methyl group.

（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）アクリロイルオキシ基であり、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。）
ここで、一般式（１０）中のＷ（２価の有機基）の例としては、下記一般式（１１）で表される構造や、フェニレン基等が挙げられる。

（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（１０）中のＺ（２価の有機基）の例としては、メチレンまたは炭素数２〜８のアルキレン基等が挙げられる。 Preferable examples of the repeating unit represented by the general formula (8) include a repeating unit represented by the following general formula (10).

(Wherein R ¹ is a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, R ³ is a (meth) acryloyloxy group, and W and Z are each independently a single bond or a divalent organic group. is there.)
Here, examples of W (divalent organic group) in the general formula (10) include a structure represented by the following general formula (11), 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 (10) include methylene or an alkylene group having 2 to 8 carbon atoms.

（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 (9) include a structure represented by the following general formula (11), 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 5,000 to 100,000, more preferably 8,000 to 70,000, and particularly preferably 10,000 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 composition layer having a certain thickness when forming an optical waveguide. When the value exceeds 100,000, the viscosity of the composition increases, and there are disadvantages such as poor applicability of the radiation curable composition when forming an optical waveguide.
As the method for producing the component (a), for example, the radical polymerizable compound having a hydroxyl group and the component (b) (radical polymerizable compound corresponding to the general formula (8)) are used for radical polymerization in a solvent. And (c) an isocyanate having a (meth) acryloyloxy group is added to the hydroxyl group of the side chain of the copolymer after radical polymerization in the presence of the catalyst.

  The glass transition temperature of the component (A) obtained by the above method is preferably 20 ° C. or higher and 150 ° C. or lower. 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 is difficult to form a layer made of a radiation curable composition or a radiation curable composition layer when forming an optical waveguide. There are inconveniences such as stickiness and poor workability. On the other hand, if the glass transition temperature of the component (a) exceeds 150 ° C., the cured product layer of the radiation curable composition may become hard or brittle, resulting in poor adhesion.

[(B) component]
The component (b) is a compound having a straight chain structure having a urethane bond repeatedly generated by reacting a polyol compound and a polyisocyanate compound, and having 2 to 6 (meth) acryloyl groups.
The component (b) is obtained, for example, by reacting a polyol compound, a polyisocyanate compound, and a hydroxyl group-containing (meth) acrylate.
(B) As a manufacturing method of a component, the following manufacturing methods 1-4 are mentioned, for example.
Production method 1: A method in which a polyol compound, a polyisocyanate compound and a hydroxyl group-containing (meth) acrylate are charged and reacted together.
Production method 2: A method in which a polyol compound 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 a polyol compound is reacted.
Production Method 4: A method in which a polyisocyanate compound and a hydroxyl group-containing (meth) acrylate are reacted, then a polyol compound 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) Polyol compound The polyol compound which is one of the raw materials of the component (b) of the present invention is a compound having two or more hydroxyl groups in the molecule. Examples of such compounds include aromatic polyether polyols, aliphatic polyether polyols, alicyclic polyether polyols, polyester polyols, polycarbonate polyols, polycaprolactone polyols, and the like.
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.

  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 radiation curable composition is applied to form the composition layer 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 radiation curable composition layer. In addition, when the number average molecular weight exceeds 100,000, the viscosity of the radiation curable composition becomes too high, and the coating property when forming the composition layer by applying the radiation curable composition is deteriorated. There is.
In the radiation curable composition for optical waveguides, the amount of component (b) is preferably 10 to 100 parts by weight, more preferably 20 to 80 parts by weight, particularly preferably 100 parts by weight of component (b). Is 35 to 70 parts by mass. When the blending amount is less than 10 parts by mass, sufficient bending resistance may not be obtained for a cured product (for example, a cladding layer) of the radiation curable composition layer. On the other hand, when the blending amount exceeds 100 parts by mass, the compatibility with the component (a) is deteriorated, and the surface of the cured product of the radiation curable composition layer (for example, the clad layer) is roughened or sufficiently Transparency may not be obtained.

[(C) component]
The 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.
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 Examples include (meth) acrylate.
Component (c) may be used alone or in combination of two or more.
In the radiation curable composition for optical waveguides, the amount of component (c) is preferably 5 to 100 parts by weight, more preferably 10 to 70 parts by weight, particularly preferably 100 parts by weight of component (b). Is 20-50 parts by mass. When the said compounding quantity is less than 5 mass parts, when forming an optical waveguide, the precision of the shape of the target waveguide may be inferior. On the other hand, if the blending amount exceeds 100 parts by mass, the compatibility with the component (a) may deteriorate, and film roughness may occur on the surface of the cured product (eg, clad layer) of the radiation curable composition.

[(D) ingredient]
The component (d) is a radical photopolymerization 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 radical photopolymerization 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, diethyl Oxanthone, 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 products of photo radical polymerization 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 photoinitiator is used individually by 1 type or in combination of 2 or more types.

In the radiation curable composition for optical waveguides, the blending ratio of component (d) is preferably 0.1 to 10% by mass, more preferably 0.2 to 100% by mass, based on the total amount of the radiation curable composition. 5% by mass. When the blending ratio 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, when the said mixture ratio exceeds 10 mass%, a photoinitiator may have a bad influence on a long-term transmission characteristic.
In the radiation curable composition for optical waveguides, a photosensitizer can be blended together with the above-described photopolymerization initiator. 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.

The radiation curable composition for optical waveguides can contain other arbitrary components as needed in addition to the components (a) to (d). Other optional components include, for example, a compound having one polymerizable reactive group in the molecule, a polymer resin (for example, epoxy resin, acrylic resin, polyamide resin, polyamideimide resin, polyurethane resin, polybutadiene resin, polybutadiene resin). Chloroprene 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 included.
In order to prepare a radiation curable composition for an optical waveguide, the above-mentioned components may be mixed and stirred according to a conventional method.

Next, the opto-electric hybrid board 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 opto-electric hybrid board of the present invention.
In FIG. 1, the opto-electric hybrid board 1 includes a polyimide film 2 on which a metal wiring 6 is formed, an adhesive layer 3, and a film-like optical waveguide 4. The polyimide film 2 on which the metal wiring is formed includes a polyimide film 5 and a metal wiring 6 having a specific width formed on the upper surface of the polyimide film 5. The film-shaped optical waveguide 4 is formed by laminating the lower clad layer 7, the core portion 8 having a specific width formed on the upper surface of the lower clad layer 7, and the upper surfaces of the lower clad layer 7 and the core portion 8. The core portion 8 is embedded in the lower clad layer 7 and the upper clad layer 9 that form the outer shape of the film-like optical waveguide 4. The film-shaped optical waveguide 4 and the polyimide film 2 on which the metal wiring is formed are such that the surface 10 (the upper surface of the polyimide film 2 in FIG. 1) on which the metal wiring 6 of the polyimide film 2 is formed is They are laminated via an adhesive layer 3 so as to face the outer surface (the lower cladding layer 7 in FIG. 1).
Although the thickness of a polyimide film is not specifically limited, For example, it is 12-38 micrometers. Moreover, although the thickness of the metal wiring formed on a polyimide film is not specifically limited, For example, it is 5-15 micrometers. Although the width | variety of metal wiring is not specifically limited, For example, it is 1-200 micrometers.
The thickness of the adhesive layer is 5 to 30 μm, preferably 10 to 20 μm.
The thicknesses of the lower cladding layer, the core portion, and the upper cladding layer are not particularly limited. For example, the thickness of the lower cladding layer is 1 to 200 μm, the thickness of the core portion is 3 to 200 μm, and the thickness of the upper cladding layer. Is determined to be 1 to 200 μm. Although the width | variety of a core part is not specifically limited, For example, it is 1-200 micrometers.
The refractive index of the core portion needs to be higher than any of the refractive indexes of the lower cladding layer and the upper cladding layer. For example, for light having a wavelength of 400 to 1,600 nm, the refractive index of the core portion is 1.420 to 1.650, the refractive indexes of the lower cladding layer and the upper cladding layer are 1.400 to 1.648, and The refractive index of the core portion is preferably at least 0.1% greater than the refractive index of any of the two cladding layers.

Next, a method for manufacturing an opto-electric hybrid board according to the present invention will be described with reference to the drawings. FIG. 2 is a flowchart showing an example of a method for manufacturing an opto-electric hybrid board according to the present invention.
The method for manufacturing an opto-electric hybrid board 1 of the present invention includes a step of preparing a polyimide film 2 on which metal wiring is formed, a step of forming an adhesive layer 3, and a step of forming a film-like optical waveguide 4. .
The step of forming the adhesive layer 3 is a step of forming a cured product by irradiating the radiation curable composition for the adhesive layer described above with radiation.
The step of forming the film-like optical waveguide 4 includes the step of forming the lower clad layer 7, the step of forming the core portion 8, and the step of forming the upper clad layer 9.
In addition, the radiation curable composition for forming the adhesive bond layer 3 is called the composition for adhesive bond layers for convenience. Moreover, the radiation curable composition for forming each part of the lower clad layer 7, the core part 8 and the upper clad layer 9 constituting the film-shaped optical waveguide 4 is respectively a lower layer composition and a core composition for convenience. And an upper layer composition.

(1) Preparation of radiation-curable composition As the composition for an adhesive layer, the above-mentioned radiation-curable composition for an adhesive layer is prepared.
As the lower layer composition, core composition and upper layer composition, a radiation curable composition, preferably the above-described radiation curable composition for an optical waveguide, is prepared. The component composition of each of the lower layer composition, the core composition, and the upper layer composition is such that the relationship between the refractive indices of the lower cladding layer 7, the core portion 8 and the upper cladding layer 9 is required for the optical waveguide. To be satisfied. Specifically, two or three types of radiation curable compositions are prepared so that the difference in refractive index has an appropriate magnitude. Among these, the radiation curable composition that gives the cured film having the highest refractive index is used as the core. Other radiation-curable compositions are used as the lower layer composition and the upper layer composition.
The lower layer composition and the upper layer composition are preferably the same radiation-curable composition in terms of economy and production management.
The viscosity of the radiation curable composition (adhesive layer composition, lower layer composition, core composition and upper layer composition) is preferably 1 to 10,000 cps (25 ° C.), more preferably 5 to 8. 1,000 cps (25 ° C.), particularly preferably 10 to 5,000 cps (25 ° C.). When the viscosity is outside this range, it may be difficult to handle the radiation curable composition or form a uniform coating film. In addition, a viscosity can be suitably adjusted by changing compounding quantities, such as an organic solvent.

(2) Preparation of polyimide film on which metal wiring is formed As shown in (a) in FIG. 2, a polyimide film 2 on which metal wiring 6 is formed on one side is prepared.
Examples of the polyimide film on which the metal wiring is formed include those in which a patterned metal wiring having a specific width is formed on at least one surface of the polyimide film. In FIG. 2, the polyimide film 2 on which the metal wiring 6 is formed includes a polyimide film 5 and a metal wiring 6 formed on the upper surface of the polyimide film 5.
A copper wiring is a suitable example of the metal wiring.
In addition, the polyimide film 2 in which the metal wiring was formed can be manufactured by the following methods, for example.
First, a polyimide film 15 with a copper foil comprising a polyimide film 5 and a copper foil 14 formed on the upper surface of the polyimide film 5 is prepared ((a) in FIG. 3), and a resist layer 16 is formed on the upper surface of the copper foil 14. ((B) in FIG. 3). Next, the resist layer 16 is irradiated with light through the photomask 17 ((c) in FIG. 3). As a result, only the portion of the resist layer 16 irradiated with light is cured, so that the uncured portion other than that is developed and removed, whereby the patterned curing made of resist is formed on the upper surface of the copper foil 14. A film 18 can be formed ((d) in FIG. 3). Next, using the cured film 18 made of resist as a mask, the copper foil 14 is etched ((e) in FIG. 3), and when the cured film 18 made of resist is removed, patterned copper is formed on the upper surface of the polyimide film 5. A metal wiring (copper wiring) 6 made of foil can be formed.
As said polyimide film with copper foil, PI-25D-CCS-08D0 (made by Toray Film Processing Co., Ltd.) etc. are mentioned, for example.
Examples of the material for forming the resist layer include THB-110N (manufactured by JSR).

(3) Formation process of an adhesive bond layer The adhesive bond layer 3 is formed in the upper surface of the polyimide film 2 in which the metal wiring 6 was formed. Specifically, the adhesive layer composition is applied to the surface 10 of the polyimide film 2 on which the metal wiring 6 is formed (the upper surface of the polyimide film 2 in FIG. 2), and dried or prebaked as necessary. To form a thin film for the adhesive layer. Next, the adhesive layer thin film is irradiated with light and cured to form an adhesive layer 3 that is a cured body ((b) in FIG. 2). In addition, in the formation process of the adhesive bond layer 3, it is preferable to irradiate the whole surface of a thin film and to harden the whole.
Here, as a coating method of the composition for the adhesive layer, any of spin coating method, dipping method, spray method, bar coating method, roll coating method, curtain coating method, gravure printing method, silk screen method, ink jet method, etc. Any method can be used. Among these, since the thin film for adhesive layers of uniform thickness is obtained, it is preferable to employ | adopt a spin coat method.
In order to make the rheological properties of the adhesive layer composition appropriate for the coating method, the adhesive layer composition includes various leveling agents, thixotropic agents, fillers, organic solvents, surfactants. Etc. are preferably blended as necessary.
The temperature at the time of the prebaking is, for example, 50 to 150 ° C. The organic solvent can be removed by pre-baking.
The application method in the adhesive layer forming step, the improvement of rheological characteristics, and the like are the same in the lower clad layer forming step, the core portion forming step, and the upper clad layer forming step, which will be described later.

The irradiation amount of light when forming the adhesive layer is not particularly limited, but light having a wavelength of 200 to 390 nm and an illuminance of 1 to 500 mW / cm ² is irradiated with an irradiation amount of 10 to 5,000 mJ / cm ^2. It is preferable that the exposure is performed by irradiation.
Visible light, ultraviolet rays, infrared rays, X-rays, α rays, β rays, γ rays and the like can be used as the type of light to be irradiated, and ultraviolet rays are particularly preferable. As the light irradiation device, for example, a high pressure mercury lamp, a low pressure mercury lamp, a metal halide lamp, an excimer lamp or the like is preferably used.
Moreover, it is preferable to perform a heat treatment (post-bake) after the exposure. This heating condition varies depending on the component composition of the radiation curable composition, but is usually 30 to 200 ° C., preferably 50 to 150 ° C., for example, a heating time of 5 minutes to 3 hours. By performing the heat treatment (post-bake), the entire surface of the coating film can be sufficiently cured.
Note that the pre-bake conditions, light irradiation amount, type, and light (ultraviolet) irradiation device in the adhesive layer forming step are as follows: lower clad layer forming step, core portion forming step, upper clad layer The same applies to the forming step. The post-baking conditions in the adhesive layer forming step are the same in the lower clad layer forming step and the upper clad layer forming step, which will be described later.

(4) Step of forming lower clad layer The lower clad layer 7 is formed on the upper surface of the adhesive layer 3. Specifically, the lower layer composition is applied to the upper surface of the adhesive layer 3 and, if necessary, dried or prebaked to form a lower layer thin film. The lower layer thin film is irradiated with light and cured to form a lower clad layer 7 as a cured body ((c) in FIG. 2). In the step of forming the lower clad layer 7, it is preferable to irradiate the entire surface of the thin film with light and harden the whole.
The lower clad layer 7 can also be formed using a dry film including a base film and a layer made of a composition for a lower layer formed by being laminated on the base film. In this case, the dry film is laminated on the upper surface of the adhesive layer 3 so that the layer made of the lower layer composition faces the adhesive layer 3. Next, light is irradiated from the upper surface of the base film to cure the layer made of the lower layer composition, thereby forming the lower cladding layer 7 which is a cured body.

(5) Core Part Formation Step The core part 8 is formed on the upper surface of the lower cladding layer 7. Specifically, as shown in (d) of FIG. 2, the core composition is applied and dried or prebaked as necessary to form the core thin film 11. Thereafter, as shown in FIG. 2 (e), irradiation (exposure) of light 13 is performed on the upper surface of the core thin film 11 according to a predetermined pattern, for example, through a photomask 12 having a predetermined line pattern. Do. As a result, only the portion irradiated with light in the core thin film 11 is cured, so that other uncured portions are developed and removed, as shown in FIG. On the lower clad layer 7, the core portion 8 made of a patterned cured film can be formed.
The core portion 8 is preferably post-baked. By post-baking the core portion 8, further hardening can be achieved. The post-bake may be heated by a heating device such as a hot plate or an oven, for example, at a temperature of 30 to 150 ° C. for 5 to 180 minutes.

In FIG. 2 (e), the method of performing light irradiation 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. 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. Therefore, after pattern exposure, while removing an uncured part and leaving a cured part, the core part 8 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.
In addition, the core part 8 can also be formed using the dry film containing the layer which consists of a base film and the composition for cores formed by laminating | stacking on this base film. In this case, the dry film is laminated on the upper surface of the lower cladding layer 7 so that the layer made of the core composition faces the lower cladding layer 7. Next, the core composition 8 is cured by irradiating light in accordance with a predetermined pattern from the upper surface of the base film, and the uncured portion is developed and removed to form the core portion 8.

(6) Step of forming upper clad layer The upper clad layer 9 is formed on the upper surfaces of the core portion 8 and the lower clad layer 7. Specifically, the upper layer composition is applied to the upper surfaces of the core portion 8 and the lower clad layer 7, and dried or prebaked as necessary to form an upper layer thin film. When the upper thin film is cured by irradiation with light, an upper clad layer 9 is formed ((g) in FIG. 2). The upper clad layer 9 can be heat-treated (post-baked) as necessary. By performing the heat treatment (post-bake), the entire surface of the coating film can be sufficiently cured.
The upper clad layer 9 can also be formed using a dry film including a base film and a layer made of an upper layer composition formed by being laminated on the base film. In this case, the dry film is laminated on the upper surfaces of the lower cladding layer 7 and the core portion 8 so that the layer made of the upper layer composition faces the lower cladding layer 7 and the core portion 8. Next, light is irradiated from the upper surface of the base film to cure the layer made of the upper layer composition, thereby forming the upper clad layer 9 that is a cured body.
In addition, after the formation of the upper clad layer, a polyimide film having no metal wiring can be laminated on the upper surface of the upper clad layer (not shown). By providing a polyimide film having no metal wiring, the surface of the film-shaped optical waveguide can be protected, and mechanical durability and heat resistance can be improved.
Examples of the polyimide film include Kapton (manufactured by Toray DuPont) and Upilex (manufactured by Ube Industries).
Examples of the laminating method include thermal bonding with a thermosetting epoxy resin.

  The resulting opto-electric hybrid board has excellent adhesion between the polyimide film on which the metal wiring is formed and the adhesive layer, and excellent adhesion between the film-like optical waveguide and the adhesive layer, so that the metal wiring is formed. The formed polyimide film and the film-like optical waveguide are firmly bonded via an adhesive layer.

Hereinafter, the present invention will be specifically described by way of examples.
[Examples 1 to 3, Comparative Examples 1 to 4]
(Curable composition for adhesive layer)
A curable composition for the adhesive layer was prepared by blending each component at a blending ratio shown in Table 1 and mixing them uniformly.
Subsequently, adhesiveness was evaluated by the following method using the obtained curable composition for adhesive layers. The results are shown in Table 1.
(Curable composition for clad layer)
The following components (a) to (e) are prepared as materials for the curable composition for the clad layer. (A) component: 100 parts by mass, (b) component: 43 parts by mass, (c) component: 43 parts by mass (D) component: 3 parts by mass, (e) component: mixed at a blending ratio of 95 parts by mass to obtain a curable composition for a cladding layer.
[(I) component]
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 carried out 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 carried out three times in total, the obtained coagulated product was vacuum-dried at 40 ° C. for 48 hours to obtain the desired copolymer as component (a).

[(B) component]
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. When the residual isocyanate was 0.1% by mass or less, the reaction was terminated, and the component (b) was obtained.
[(C) component]
Trimethylolpropane triacrylate (boiling point at 0.1 MPa: 315 ° C., manufactured by Osaka Organic Chemical Industry Co., Ltd.)
[(D) ingredient]
Photoradical polymerization initiator (trade name “Irgacure 369”, manufactured by Ciba Specialty Chemicals)
[(E) Component (organic solvent)]
Propylene glycol monomethyl ether acetate

(Adhesiveness with clad layer)
From the curable composition, apply the curable composition for the adhesive layer obtained above on a polyimide film (Kapton manufactured by Toray DuPont; thickness: 25 μm) and dry at 120 ° C. for 5 minutes. A coating film was formed. Next, using the aligner manufactured by SUSS, the entire surface of the coating film was cured by irradiation with light under the conditions of an illuminance of 20 mW / cm ² and an irradiation light amount of 1.5 J / cm ^2. Agent layer) was formed. Thereafter, the clad layer curable composition obtained above was applied to the upper surface of this cured product layer, dried at 120 ° C. for 5 minutes, and then cured by irradiation with light under the same conditions as above. A cured product layer (cladding layer) having a thickness of 70 μm was formed to obtain a laminate in which a polyimide film, an adhesive layer, and a cladding layer were laminated in this order.
In the obtained laminate, the adhesive layer and the clad layer were peeled off by hand, and the case where peeling was not carried out was “◯”, and the case where peeling was made was “x”.

(Adhesiveness with polyimide film)
A laminate was obtained in the same manner as the adhesiveness to the clad layer. In the laminate, the adhesive strength between the adhesive layer and the polyimide film was measured by performing a 180 ° peel test under a condition of 50 mm / min using an Instron tensile tester. The case where the adhesive strength was 200 N / m or more was “◯”, and the case where it was less than 200 N / m was “x”.

(Adhesiveness with copper)
Using a polyimide film having a copper foil on one side (PI-25D-CCS-08D0 manufactured by Toray Film Processing Co., Ltd.), the curable composition for the adhesive layer is applied to the upper surface of the copper foil and dried at 120 ° C. for 5 minutes. And a coating film made of the curable composition was formed. Next, using the aligner manufactured by SUSS, the entire surface of the coating film was cured by irradiation with light under the conditions of an illuminance of 20 mW / cm ² and an irradiation light amount of 1.5 J / cm ^2. By forming the (agent layer), the laminated body formed by laminating the polyimide film, the copper foil, and the adhesive layer in this order was obtained.
In the obtained laminate, the adhesive strength between the copper foil and the adhesive layer was measured by performing a 180 ° peel test under a condition of 50 mm / min using an Instron tensile tester. The case where the adhesive strength was 200 N / m or more was “◯”, and the case where it was less than 200 N / m was “x”.

  From Table 1, according to the radiation curable composition for adhesive layers of the present invention (Examples 1 to 3), at the interface between each of the copper foil (metal wiring), the polyimide film, and the cladding layer and the adhesive layer, It can be seen that high adhesion can be obtained. On the other hand, in Comparative Examples 1-4 using the composition which does not belong to this invention as a composition for adhesive layers, adhesion in the interface of each of copper foil (metal wiring), a polyimide film, and a cladding layer and an adhesive layer is carried out. It turns out that either of them is inferior.

It is sectional drawing which shows an example of the opto-electric hybrid board | substrate of this invention. It is a flowchart which shows an example of the manufacturing method of the opto-electric hybrid board of this invention. It is a flowchart which shows an example of the manufacturing method of the polyimide film in which the metal wiring was formed.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Opto-electric hybrid board 2 Polyimide film in which metal wiring is formed 3 Adhesive layer 4 Film-shaped optical waveguide 5 Polyimide film 6 Metal wiring 7 Lower cladding layer 8 Core portion 9 Upper cladding layer 10 Polyimide film in which metal wiring is formed Surface on which metal wiring is formed 11 Core thin film 12 Photomask 13 Light 14 Copper foil 15 Polyimide film with copper foil 16 Resist layer 17 Photomask 18 Cured film made of resist

Claims (6)

An opto-electric hybrid board including a film-shaped optical waveguide including a core portion and a cladding layer and a polyimide film on which metal wiring is formed, wherein the film-shaped optical waveguide and the polyimide film are metal of the polyimide film. It is laminated through an adhesive layer so that the surface on which the wiring is formed faces at least one outer surface of the film-shaped optical waveguide, and the adhesive layer contains the following components (A) to (D): An opto-electric hybrid board comprising a cured product of a radiation curable composition.
(A) Polyimide silicone resin containing a structural unit represented by the following general formula (1) and a structural unit represented by the following general formula (2) (B) Compound containing two or more oxiranyl groups (C) Oxetanyl Compound (D) Cationic Photopolymerization Initiator Containing Two or More Groups

(Wherein, X ¹ and X ² are each independently a tetravalent organic group, Y is a divalent organic group, and Z is a divalent organic group having an organopolysiloxane structure).   The photoelectric hybrid substrate according to claim 1, wherein the radiation curable composition further comprises (E) a compound having at least one (meth) acryloyl group and at least one epoxy group in the molecule. . The opto-electric hybrid board according to claim 1 or 2, wherein the radiation curable composition further comprises (F) a compound having a structure represented by the following general formula (4).

(Wherein R ¹ is an organic group having a polymerizable carbon-carbon double bond, R ² and R ³ are each independently an alkyl group having 1 to 10 carbon atoms or a halogenated group having 1 to 10 carbon atoms. An alkyl group, an aralkyl group having 7 to 11 carbon atoms, a monovalent alicyclic group having 3 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms.) The opto-electric hybrid board according to any one of claims 1 to 3, wherein the component (F) comprises one or more components selected from the group consisting of the following (a), (b), and (c).
(A) Compound having at least two polymerizable carbon-carbon double bonds in the molecule and having a structure represented by the general formula (4) (b) Polymerizable carbon-carbon in the molecule A compound having one double bond and represented by the following general formula (5) or (6)

(In the formula, R ⁴ represents an organic group having a polymerizable carbon-carbon double bond, R ⁵ represents an alkyl group having 1 to 10 carbon atoms, and R ⁶ and R ⁷ each independently represents 1 carbon atom. An alkyl group having 10 to 10 carbon atoms, a monovalent alicyclic group having 6 to 20 carbon atoms, or a monovalent aryl group having 6 to 20 carbon atoms.)

(In the formula, R ⁸ is an organic group having a polymerizable carbon-carbon double bond, R ⁹ is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alicyclic group having 3 to 10 carbon atoms, or 6 carbon atoms. Represents an aryl group having 10 to 10 carbon atoms or an aralkyl group having 7 to 11 carbon atoms, and R ¹⁰ and R ¹¹ are each independently an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group having 1 to 10 carbon atoms, carbon Represents an alicyclic group having 3 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms or an aralkyl group having 7 to 11 carbon atoms, or any two of R ⁹ , R ¹⁰ and R ¹¹ are bonded to each other. And may form a 5- to 7-membered ring.)
(C) a (co) polymer comprising a structural unit derived from the compound (a) and / or a structural unit derived from the compound (b)   The opto-electric hybrid board according to any one of claims 1 to 4, wherein the radiation curable composition further comprises (G) a radical photopolymerization initiator.   The said film-form optical waveguide has a polyimide film which does not have a metal wiring in the outer surface on the opposite side to the side which has a polyimide film in which the metal wiring was formed, The light of any one of Claims 1-5. Electric mixed board.

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