TWI415877B - Flexible optical waveguides and laminates for optical - electrical composite wiring boards - Google Patents

Abstract

A flexible optical/electrical composite wiring board excelling in repeated flexure and ensuring high reliability is obtained through combining of a light guide of polyimide resin with a flexible copper-clad laminate. The light guide has a cladding layer and a core layer. The cladding layer is formed from a light guide material composed mainly of a siloxane-modified polyimide resin. The core layer is formed from a light guide material exhibiting a refractive index different from that of the cladding layer. A material composed mainly of a siloxane-modified polyimide resin is suitable as the light guide material for the core layer. Use of a resin composition containing a photosensitive resin as the light guide material for the core layer would enable easily forming of desired pattern. The optical/electrical composite wiring board can be obtained by superimposing a cladding layer and a core layer on a flexible printed wiring board so that the core layer is surrounded by the cladding layer.

Description

Flexible optical waveguide and laminate for optical-electric composite wiring board

The present invention relates to a flexible optical waveguide formed of a material of a polyimide resin-based material and a laminate for an optical-electric composite wiring board forming the optical waveguide.

In recent years, optical communication technologies capable of high-speed and large-capacity data communication have made remarkable progress, and their optical communication networks have continued to expand. Optical communication technology is now used for long-distance communication and medium-range communication in the region, but in the future it will be applied to optical signal transmission inside and between machines.

In portable devices, small machines, and the like, since various members are densely arranged, it is necessary to pass through a narrow gap between the members for wiring. Therefore, a flexible printed wiring board is widely used as an electrical wiring. Similarly, an optical wiring board (optical circuit wiring board) composed of a flexible optical waveguide is desired for transmitting optical signals within a short distance between the inside of the machine and the machine.

Therefore, it is expected to develop a flexible optical-electric composite wiring board in which an optical wiring board composed of such a flexible optical waveguide and an electrical wiring board formed of a flexible printed wiring board are integrated.

Several optical waveguide materials have been proposed for use in optical-electric composite wiring boards.

[Patent Document 1] Japanese Laid-Open Patent Publication No. 2004-149724 (Patent Document 3) JP-A-2005-43497

Patent Document 1 is an optical waveguide formed by curing a photocurable and thermosetting epoxy resin film. Since the optical waveguide material forms a crosslinked structure via a hardening reaction, flexibility is insufficient, and it is particularly difficult to apply to a portion of the hinge portion of a mobile phone or the like which must have repeatability. Moreover, since the epoxy resin has a high water absorption rate, it is feared that the characteristics in the high temperature-high humidity state deteriorate.

Patent Document 2 is an optical waveguide in which a polyimide resin is proposed. Since the optical waveguide material contains fluorine in the polyimine structure, when it is composited with the flexible printed wiring board, it is likely to be inferior in adhesion to the flexible substrate interface. Further, the fluorine-based material is generally expensive, and is disadvantageous to the cost when it is put into practical use. Patent Document 3 proposes an optical waveguide in which the upper cladding layer is a two-layer optical layer, and is inferior in flexibility because it is an inorganic material.

In view of the above problems, the present invention has been made in order to provide a flexible (electrically flexible) wiring board which is flexible (low elasticity) and low in water absorption. A waveguide and a laminate for an optical-electric composite wiring board having such an optical waveguide and having excellent repeatability and reliability are desired.

The inventors have found that the above object can be attained by using a polyimine resin having a specific configuration, and the completion of the present invention is achieved.

That is, in the optical waveguide having the cover layer and the core layer, the cover layer is an optical waveguide using a polyimine resin having a constituent unit represented by the following general formulas (1) and (2) as a main component. The material is formed into a flexible optical waveguide characterized by it.

(However, Ar ₁ and Ar ₂ is independently represented by the formula (3), the tetravalent aromatic group, Ar ₃ is represented by the formula (4) or (5) of the divalent aromatic group, R ₁ is independently The carbon number is 1 to 6 one-valent hydrocarbon groups, R ₃ is a divalent hydrocarbon group independently representing 2 to 6 carbon atoms, and R ₄ is independently a hydrocarbon group having 1 to 6 carbon atoms, and X and Y are independent representations. A single bond or a divalent group selected from 1 to 15 carbon atoms, O, S, CO, SO ₂ or CONH, m is a number from 1 to 50, and n is an integer representing 0 to 4 independently. , p and q are the molar ratios of the constituent units, p is in the range of 0.05 to 0.99, and q is in the range of 0.01 to 0.95.

The optical waveguide of the present invention is preferably one or more of the following.

1) The core layer is formed using the above-described optical waveguide material having a refractive index different from that of the cover layer.

2) The elastic modulus of the polyimide resin is in the range of 0.2 to 3.0 GPa.

3) The refractive index difference Δ of the optical waveguide material forming the core layer and the cladding layer is 0.01 or more.

4) The optical waveguide is a cover layer having a core layer and covering the periphery of the core layer, and the cover layer has a lower refractive index than the core layer.

Moreover, the present invention is a laminate for an optical-electric composite wiring board or an optical-electric composite flexible member in which the optical waveguide described above is formed on a flexible copper-clad laminate or a flexible wiring board. Wiring board. Here, the flexible copper clad laminate means a laminate before forming a circuit, and the flexible wiring board means a wiring board forming a circuit. The circuit can be formed by etching a copper foil layer of a flexible copper clad laminate.

The optical waveguide of the present invention has a core layer and a cover layer. The cover layer is an optical waveguide material using a polyimine resin having a structural unit represented by the above general formulas (1) and (2) (hereinafter, also referred to as a decane-modified polyimine resin) as a main component. Formed.

The alkane-modified polyimine resin used in the present invention has the structural unit represented by the above general formulas (1) and (2).

In the general formulae (1) and (2), Ar ₁ and Ar ₂ are independently a tetravalent aromatic group represented by the formula (3), and Ar ₃ is represented by the formula (4) or the formula (5). The valent aromatic group, R ₃ is a divalent hydrocarbon group independently represented by 2 to 6 carbon atoms, R ₄ is independently a hydrocarbon group having 1 to 6 carbon atoms, and m is a number of 1 to 50. Here, the case where plural R ₃ , R _{4 ,} and the like are present in one constituent unit may be independently changed in the above range. Further, when there are a plurality of constituent units in one molecule, Ar ₁ , Ar ₂ , Ar ₃ , and R ₃ to R ₄ may be independently changed in the above range. Further, when the siloxane-modified polyimine resin is composed of a plurality of molecules, each molecule may be independently changed in the above range. Further, the same applies to Y and X, R ₁ and n described below.

In the formulae (3), (4) and (5), X and Y are independently a single bond, or a divalent hydrocarbon group having 1 to 15 carbon atoms, O, S, CO, SO ₂ or CONH. The selected divalent group, R ₁ is an independently represented hydrocarbon having 1 to 6 carbon atoms, and n is an integer representing 0 to 4. As described above, Ar ₃ is a divalent aromatic group represented by the formula (4), and may be a divalent aromatic group represented by the formula (5), and may have two in one molecule or several molecules. By.

Ar ₁ and Ar ₂ are a tetravalent group represented by the formula (3), and the polyimine resin is usually synthesized by reacting an aromatic tetracarboxylic acid such as an aromatic tetracarboxylic dianhydride with a diamine, so Ar ₁ and Ar are synthesized. ₂ may be referred to as a residue of an aromatic tetracarboxylic acid. Therefore, Ar ₁ to Ar ₂ are understood to be the aromatic tetracarboxylic acids used for the description of the synthesis. However, the alkane-modified polyimine resin used in the present invention is not limited to the polyimide resin obtained by such a synthesis method. Further, Ar ₁ and Ar ₂ may be the same or different, and Ar ₁ or Ar ₂ may be composed of a plurality of tetravalent groups.

In the formula (3), Y is a divalent group selected from a single bond, a divalent hydrocarbon group having 1 to 15 carbon atoms, O, S, CO, SO ₂ or CONH. It preferably represents a single bond or a divalent group selected from O, CO and SO ₂ . The divalent hydrocarbon group is preferably an alkylene group having 1 to 6 carbon atoms (including the meaning of an alkylene group) and a phenyl group.

The aromatic tetracarboxylic acid which preferably provides Ar ₁ and Ar ₂ is represented by acid dianhydride.

Specifically, 2,2',3,3'-, 2,3,3',4'- or 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 3 is preferable. , 3',4,4'-biphenyltetracarboxylic dianhydride, 2,3',3,4'-biphenyltetracarboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic acid Dianhydride, 3,3',4,4'-diphenyltetracarboxylic anhydride, 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride, 2,3',3,4'-di Phenyl ether tetracarboxylic dianhydride, bis(2,3-dicarboxyphenyl) ether dianhydride, and the like. Further, 3, 3", 4, 4"-, 2, 3, 3", 4"- or 2, 2", 3, 3"-p-terphenyltetracarboxylic dianhydride, 2, 2 may also be mentioned. - bis(2,3- or 3,4-dicarboxyphenyl)-propane dianhydride, bis(2,3- or 3,4-dicarboxyphenyl)methane dianhydride, bis (2,3- or 3) , 4-dicarboxyphenyl) phthalic anhydride, 1,1-bis(2,3- or 3,4-dicarboxyphenyl)ethane dianhydride.

Ar ₁ may also be provided and Ar ₂ of the aromatic tetracarboxylic acid, the four other commonly used acids. When the other tetracarboxylic acid is used, it is used in an amount of 50 mol% or less, preferably 20 mol% or less, based on the total aromatic tetracarboxylic acid.

Such other tetracarboxylic acids are exemplified by the acid dianhydride form. Also included are pyromellitic dianhydride, 2,3,5,6-cyclohexane dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic acid Acid dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 4,8-dimethyl-1,2,3,5,6,7-hexahydronaphthalene-1,2,5,6 -tetracarboxylic dianhydride, 2,6- or 2,7-dichloronaphthalene-1,4,5,8-tetracarboxylic dianhydride, 2,3,6,7- (or 1,4,5 , 8-) tetrachloronaphthalene-1,4,5,8-(or 2,3,6,7-)tetracarboxylic dianhydride, 2,3,8,9-,3,4,9,10 -, 4,5,10,11- or 5,6,11,12-indole-tetracarboxylic dianhydride, cyclopentane-1,2,3,4-tetracarboxylic dianhydride, pyridyl -2,3,5,6-tetracarboxylic dianhydride, pyrrolidine-2,3,4,5-tetracarboxylic dianhydride, thiophene-2,3,4,5-tetracarboxylic dianhydride, 4, 4-bis(2,3-dicarboxyphenoxy)diphenylmethane dianhydride, 1,2,7,8-, 1,2,6,7- or 1,2,9,10-phenanthrene-tetra Carboxylic dianhydride, 2,3,6,7-nonanetetracarboxylic dianhydride, and the like.

In the general formula (1), the divalent aromatic group represented by Ar ₃ may be referred to as a residue of a diamine. Therefore, X, R ₁ and n in Ar ₃ or formula (4) and formula (5) can be understood by explaining the diamine used in the synthesis. Further, the constituent unit represented by the general formula (1) may be formed by a plurality of constituent units different from the divalent aromatic group.

X can be the same as Y above, but can also be different. X can be exemplified by the above Y. Preferred are a single bond or a divalent group selected from O, S, CO, SO ₂ , CONH, CH ₂ , C(CH ₃ ) ₂ and 9,9'-fluorenyl. Further, the 9,9'-fluorenyl group is represented by the following formula.

In the divalent aromatic group containing X, R ₁ is independently an alkyl group having 1 to 6 carbon atoms, preferably an alkyl group having 1 to 6 carbon atoms, an alkenyl group, a cycloalkyl group or a phenyl group. More preferably, it is an alkyl group, a vinyl group or a phenyl group having 1 to 3 carbon atoms. n is an integer representing 0 to 4, preferably 0 to 2, more preferably 0.

When Ar ₃ is a divalent aromatic group represented by the formula (5), a preferred diamine of Ar ₃ is provided.

Specific examples thereof include 2,2-bis-[4-(4-aminophenoxy)phenyl]propane and 2,2-bis-[4-(3-aminophenoxy)phenyl]propane. Bis[4-(4-aminophenoxy)phenyl]anthracene, bis[4-(3-aminophenoxy)phenyl]anthracene, bis[4-(4-aminophenoxy)]biphenyl, Bis[4-(3-aminophenoxy)biphenyl, bis[1-(4-aminophenoxy)]biphenyl, bis[1-(3-aminophenoxy)]biphenyl, bis[4 -(4-Aminophenoxy)phenyl]methane, bis[4-(3-aminophenoxy)phenyl]methane, bis[4-(4-aminophenoxy)phenyl]ether, bis[ 4-(3-Aminophenoxy)phenyl]ether, bis[4-(4-aminophenoxy)phenyl]benzophenone, bis-[4-(3-aminophenoxy)benzophenone , bis[4-(4-aminophenoxy)]benzophenone, bis[4-(3-aminophenoxy)]benzophenone, bis[4,4'-(4-aminophenoxy) Benzene aniline, bis[4,4'-(3-aminophenoxy)]phenylaniline, 9,9-bis-[4-(4-aminophenoxy)phenyl]anthracene, 9,9 - bis-[4-(3-aminophenoxy)phenyl]anthracene.

When Ar ₃ is a divalent aromatic group represented by the formula (4), a diamine which is preferably Ar ₃ is provided.

Specific examples thereof include 4,4'-methylenebis-o-toluidine, 4,4'-methylenebis-2,6-dimethylaniline, and 4,4'-methylene-2. 6-Diethylaniline, 4,4'-diaminodiphenylpropane, 3,3'-diaminodiphenylpropane, 4,4'-diaminodiphenylethane, 3,3 '-Diaminodiphenylethane, 4,4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, 4,4'-diaminodithiobenzene, 3 , 3'-diaminodithiobenzene, 4,4'-diaminodiphenyl hydrazine, 3,3'-diaminodiphenyl hydrazine, 4,4'-diaminodiphenyl ether, 3,3 '-Diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, benzidine, 3,3'-diaminobiphenyl, 3,3'-dimethyl-4,4'-di Aminobiphenyl, 3,3'-dimethoxybenzidine, 4,4"-diamino-p-terphenyl, 3,3"-diamino-p-terphenyl, 9,9-double (4-Aminophenyl)-9H-indole.

Among them, 4,4'-diaminodiphenyl ether (DAPE), 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[4-(3 -Aminophenoxy)phenyl]propane, 9,9-bis(4-aminophenyl)-9H-indole, 1,3-bis(4-aminophenoxy)benzene (TPE-R), and the like. When the amount of the other aromatic diamine other than the above is small (50 mol% or less, preferably 20 mol% or less), it may be used in combination. Further, an unsaturated group such as a 2,2'-divinyl-4,4'-diamino-biphenyl-like vinyl group is preferably a substituted diamine.

Examples of such other aromatic diamines include, for example, m-phenylenediamine, p-phenylenediamine, 2,6-diaminopyridine, 1,4-bis(4-aminophenoxy)benzene, 1, 3-bis(4-aminophenoxy)benzene, 4,4'-[1,4-phenylenebis(1-methylethylidene)]diphenylamine, 4,4'-[1,3- Phenyl bis(1-methylethylidene)]diphenylamine, bis(p-aminocyclohexyl)methane, bis(p-β-amino-t-butylphenyl)ether, double (p- --methyl-δ-aminopentyl)benzene, p-bis(2-methyl-4-aminepentyl)benzene, p-bis(1,1-dimethyl-5-aminepentyl)benzene, 1,5-Diaminonaphthalene, 2,6-diaminonaphthalene, 2,4-bis(β-amino-t-butyl)toluene, 2,4-diaminotoluene, m-xylene- 2,5-diamine, p-xylene-2,5-diamine, m-xylylenediamine, p-xylenediamine, 2,6-diaminopyridine, 2,5-diaminopyridine , 2,5-diamino-1,3,4- Diazole, piperazine Wait.

In the general formula (2), the terminal is a divalent group having a rhodium structure of R ₃ and may be referred to as a residue of a diamine. Therefore, it is understood that the divalent group having a siloxane structure or R ₃ , R ₄ and m of the general formula (2) is a diamine having a siloxane structure used for the same synthesis as described above. Further, the constituent unit represented by the general formula (2) may be formed of a plurality of constituent units different from the divalent group having the structure of the decane.

In the divalent group of the general formula (2) containing a siloxane structure, m is a number of from 1 to 50, preferably from 5 to 30. When the value is less than 1, the low modulus of elasticity (bending property) is small, and if it exceeds 50, the reactivity with tetracarboxylic dianhydride is lowered, and the molecular weight of the polymer is lowered, so that the bending property is lowered. R ₃ is a divalent hydrocarbon group having 2 to 6 carbon atoms, preferably an alkylene group having 2 to 6 carbon atoms. R ₄ is an alkyl group or a phenyl group having 1 to 6 carbon atoms, preferably a methyl group or a phenyl group.

Examples of the diamine having a preferred oxane structure include, for example, ω,ω'-bis(2-aminoethyl)polydimethyloxane, ω,ω'-bis(3-aminopropyl) polydiene. Methyl decane, ω, ω'-bis(4-aminophenyl)polydimethyl decane, ω, ω'-bis(3-aminopropyl) polydiphenyl fluorene, ω, Ω'-bis(3-aminopropyl)polydimethylphenyl sulfoxane and the like.

The oxime-modified polyimine resin used in the present invention has a constituent unit represented by the general formulae (1) and (2), and the existence unit of the general formula (1) has a molar ratio q of 0.01. ~0.95, preferably in the range of 0.5 to 0.8. The molar ratio p of the constituent unit represented by the general formula (2) is in the range of 0.05 to 0.99, preferably 0.1 to 0.8. There is a molar ratio in which the above-mentioned range is preferred when the azide-modified polyimine resin is composed of only the constituent units represented by the general formulas (1) and (2), or has other constituent units. . Further, when there are other constituent units, p + q is 0.5 or more, preferably 0.8 or more. Further, it is preferred that p/(p+q) is in the range of 0.1 to 0.8. The alkane-modified polyimine resin used in the present invention preferably has a modulus of elasticity of 0.2 to 3.0 GPa, preferably 0.3 to 3.0 GPa. Further, the glass transition temperature (Tg) is preferably in the range of 120 ° C or higher, preferably 140 to 300 ° C.

In the present invention, the core layer of the optical waveguide may also be formed of a phthalocyanine-modified polyimine, but it is advantageous to use a photosensitive material which can form an arbitrary shape pattern by photolithography in the core layer. Examples of such a photosensitive material include a polyamic acid resin having a constituent unit represented by the following general formula (6) and general formula (7), a monomer having an unsaturated bond, and a photopolymerization initiator as a main component. A resin obtained by curing a photosensitive resin composition. The core layer of the optical waveguide of the present invention is preferably a resin obtained by curing the photosensitive resin composition. Hereinafter, the resin obtained by the hardening may also be referred to as a decane-modified cross-linked polyimine resin.

In the above general formula (6) or general formula (7), Ar ₁ , Ar ₂ , R ₃ and R ₄ have the same meanings as in the above general formulas (1) and (2), and it is desirable to use the general formula (6). R _{1 in} the Ar ₃ (divalent aromatic group represented by the formula (4) or the formula (5)) or a part of R ₄ in the general formula (7) is an alkenyl group, and imparts photopolymerizability. The alkenyl group is a group represented by CH ₂ =CH-R ₆ -, and R ₆ represents a direct bond, an alkyl group having 1 to 6 carbon atoms or a phenyl group, but is preferably bonded directly in terms of reactivity. .

As the monomer having an unsaturated bond, a photopolymerizable monomer can be used, and in terms of transparency, refractive index, and the like, an acrylate such as a polyfunctional acrylate is preferable. The amount thereof is in the range of 1 to 50 parts by weight, preferably 5 to 40 parts by weight, based on 100 parts by weight of the polyamic acid resin.

The decane-modified polyimine resin can be synthesized by a known method. For example, in an organic solvent, one or more aromatic tetracarboxylic dianhydrides can be obtained by reacting two or more kinds of diamines in a ratio of about equimolar.

An example of a method for producing a polyfluorene-containing resin containing a siloxane. First, an aromatic acid dianhydride is added to a solvent and dissolved. While stirring, two or more kinds of diamines containing a nonanediamine diamine were slowly added under a nitrogen atmosphere and under ice cooling. Thereafter, the reaction mixture is stirred for 2 to 8 hours to obtain a polyamine resin solution containing a halogenated alkane. The above solvent must be inert to both the aromatic polyamic acid component and the decane component. Representative of such solvents are diethylene glycol dimethyl ether (diglyme), diethylene glycol diethyl ether, tetrahydrofuran and the like ether solvent, and N, N-dimethylformamide, N, N-dimethyl a guanamine-based solvent such as acetalamine, N-methyl-2-pyrrolidone or N-cyclohexyl-2-pyrrolidone, and more than one of these solvents may be used, and a diethylene glycol dimethyl ether solvent may be used. A solvent containing 10% by weight or more, preferably 30% by weight or more is suitable.

When the obtained phthalic acid-containing polyphthalic acid resin is treated with a heat treatment or a dehydrating agent, it can be dehydrated and closed to form a polyfluorene-containing polyamine resin. The heat treatment is carried out, for example, in a nitrogen atmosphere, and heating at 70 to 350 ° C for 2 to 5 hours. It is preferred to carry out stepwise heating in a nitrogen atmosphere at 150 ° C for 30 minutes, at 250 ° C for 30 minutes, and at 320 ° C for 1 hour. Further, by selecting a combination of a diamine and a tetracarboxylic anhydride, a polyimine resin which is soluble in a solvent can be obtained, and the mixture can be dehydrated and closed in advance, and then dissolved in a solvent to form a solution. The solution viscosity (dimethylammonium solution: concentration 25wt%) of the polyamine resin containing siloxane is 2000~50000cPa. The range of s is good.

At this time, by adjusting the order of addition of the reaction raw materials, a segmented or random type of decane-modified polyimine resin can be obtained. Further, by changing the amount of the diamine containing the oxime structure, the refractive index of the siloxane-modified polyimine resin can be controlled. In other words, when the amount of the diamine containing the siloxane structure is increased and the structural unit represented by the general formula (2) and the general formula (7) is increased, the phenomenon that the refractive index is lowered is found.

The optical waveguide of the present invention has a core layer and a cover layer. Typically, the cover layer covers the periphery of the core and the cover layer has a lower refractive index than the core layer. The optical waveguide of the present invention is formed by at least a coating layer comprising an optical waveguide material containing the above-described decane-modified polyimine resin as a main component. The core layer may also be formed of an optical waveguide material which does not contain the above-mentioned decane-modified polyimine resin, but in order to impart flexibility, the phthalocyanine-modified polyimine resin is preferably contained, preferably its precursor The oxime-modified cross-linked polyimine resin produced by the photosensitive polyamine resin is preferably formed as an optical waveguide material which is a main component of the resin. Further, the alkoxysilane-modified crosslinked polyimine resin means a polyimine resin which is formed by reacting an unsaturated group with a monomer or a resin having another unsaturated group. At this time, an optical waveguide material containing a mole-containing polyoxyimide resin having a molar ratio of a molar composition represented by the general formula (2) forms a coating layer, and is modified by at least a pyrene oxide. An imine resin or a decane-modified cross-linked polyimine resin (an optical waveguide material having a molar ratio of a molar ratio of a molar ratio of a precursor and a polyimide) Form the core layer. Hereinafter, the optical waveguide material forming the cover layer is referred to as a cover material, and the optical waveguide material forming the core layer is referred to as a core material. The refractive index of the optical waveguide material containing the decane-modified polyimine resin is preferably in the range of 1.45 to 1.65, and the refractive index difference Δ between the covering material and the core material is preferably 0.01 or more, preferably 0.02 or more.

The optical waveguide material containing the decane-modified polyimine resin of the present invention may contain 50% by weight or more, preferably 60% by weight or more of the decane-modified polyimine resin. Other compounding materials other than the decane-modified polyimine resin are a transparent resin such as a polyacrylate or an epoxy resin, and a filler such as a fine powder of cerium oxide.

The photosensitive resin composition which is preferably used for forming the core layer is a polyamine resin having a constituent unit represented by the above general formula (6) and the general formula (7), and a photopolymerization initiator as a main component, and if necessary, A monomer containing acrylate or the like (may also be a polymerizable resin component), a sensitizer, a solvent, and the like. It is preferred to use such a photosensitive resin composition (preferably a solution thereof) to form a light guide by photohardening and hydrazine imidization. Further, at this time, after the polymerization, at least a part of the vinyl group of the polyoxophthalic acid resin containing a siloxane is reacted with an unsaturated group of another monomer or resin, and the cured resin is referred to as a hydrazine-modified cross-linking. Polyimine resin.

Here, as the acrylate which can be used, for example, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxyethyl acrylate, 2-methoxyethoxyethyl acrylate can be used. Ester, 2-ethoxyethoxyethyl acrylate, tetrahydrofurfuryl acrylate, phenoxyethyl acrylate, isodecyl acrylate, stearyl acrylate, lauryl acrylate, glycidyl acrylate, allyl acrylate, acrylic acid B Oxy ester, methoxy acrylate, N,N'-dimethylamine ethyl acrylate, benzyl acrylate, 2-hydroxyethyl phthalate, dicyclopentadienyl acrylate, dicyclopentadienyl acrylate Monoacrylate, and dicyclopentadienyl acrylate, dicyclopentadienyl oxyethyl acrylate, 1,3-butylene glycol diacrylate, 1,4-butanediol diacrylate, 1,6 - Butanediol diacrylate, diethylene glycol diacrylate, neopentyl glycol diacrylate, polyethylene glycol 200 diacrylate, polyethylene glycol 400 diacrylate, polyethylene glycol 600 diacrylate , diethylene glycol diacrylate, neopentyl glycol diacrylate, hydroxytrimethyl Acetate neopentyl glycol diacrylate, triethylene glycol diacrylate, bis(propylene oxyethoxy) bisphenol A, bis(propylene oxyethoxy) tetrabromobisphenol A, tripropylene glycol II Polyfunctional acrylic acid such as acrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, bis(2-hydroxyethyl)isocyanate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, dipentaerythritol monohydroxypentaacrylate ester.

In the photosensitive resin composition, the acrylate is in an amount of from 1 to 50 parts by weight, preferably from 5 to 40 parts by weight, based on 100 parts by weight of the polyoxyphthalic acid resin containing a siloxane.

As the photopolymerization initiator, for example, acetophenone, 2,2-dimethoxyethyl benzene, p-dimethylamino acetophenone, candidone, benzyl, benzoin, benzoin methyl ether, Benzophene ether, benzoin isopropyl ether, benzoin n-propyl ether, benzoin isopropyl ether, benzoin n-butyl ether, benzyl dimethyl ketal, thioxanthone, 2-chlorothiophene Tons of ketone, 2-methylthioxanthone, 2-hydroxy-2-methyl-1-phenyl-1-one, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropane Various photopolymerization initiators such as 1-ketone, methylbenzate, and 1-hydroxycyclohexyl phenyl ketone. The photopolymerization initiator is preferably used in an amount of from 1 to 20 parts by weight, preferably from 1 to 10 parts by weight, based on 100 parts by weight of the polyphthalic acid resin containing a halogenated alkane.

Further, it is also advantageous to use a sensitizer. In this case, various amines such as benzophenone can be used as the sensitizer. The sensitizer is 0.01 to 2 parts by weight, preferably 0.05 to 0.5 parts by weight, based on 100 parts by weight of the polyphthalic acid resin containing a siloxane.

When the decane-modified polyimine resin or the resin composition containing the same as a main component is used in a solution form, it can be used in the same manner as the photosensitive resin composition in a solution form of a non-photosensitive polyamine resin composition. It is better. Moreover, such a photosensitive or non-photosensitive resin composition can adjust viscosity, etc. via various organic solvents etc.. Preferred examples of the organic solvent used in the case of use include triethylene glycol dimethyl ether, diglyme, dimethylacetamide, N-methylpyrrolidone, and propylene glycol. Methyl ether acetate (pegmia), ethyl lactate or a mixed solvent thereof. The amount of the solvent to be used is preferably 100 parts by weight based on 100 parts by weight of the solid content of the resin composition. Further, a resin composition which exhibits a liquid state at normal temperature containing 10% by weight or more of a solvent is called a varnish-like resin composition. Moreover, when the organic solvent which is a reaction solvent is used for the production of the polyamic acid resin, it is calculated by the solvent type.

Further, in the range where the characteristics of the optical waveguide are not deteriorated, other resins as described below may be used in combination. In other words, the epoxy resin is not particularly limited as long as it has a plurality of epoxy groups in one molecule, and commercially available liquid epoxy resins and solid epoxy resins can be suitably used. Specific examples of the epoxy resin include an alicyclic epoxy resin, a bisphenol A epoxy resin, a bisphenol F epoxy resin, a bisphenol S epoxy resin, and a biphenyl epoxy resin having a biphenyl skeleton. , epoxy resin containing naphthalene ring, dicyclopentadiene type epoxy resin having dicyclopentadiene skeleton, phenol novolak type epoxy resin, cresol novolak type epoxy resin, triphenylmethane type ring Oxygen resin, bromine-containing epoxy resin, aliphatic epoxy resin, triglycidyl isocyanurate or the like, and one or more of them may be used. The amount thereof is less than 40 parts by weight, preferably 30 parts by weight or less, based on 100 parts by weight of the polyimine resin or the polyaminic acid resin.

Further, in the resin, the resin composition or the resin solution containing the precursor resin of the optical waveguide material of the present invention, a thixotropic material or an inorganic filler may be added as needed within a range not impairing the characteristics of the optical waveguide. , defoamer, etc. The material for an optical waveguide of the present invention formed of the above resin composition is a fluorene-modified polyimine resin produced by imidating the oxime-modified polyimine precursor. An oxane-modified cross-linked polyimine resin is used as a main component. Here, the term "main component" means 50% by weight or more, preferably 60% by weight or more. More preferably, it is 15 to 35 parts by weight of an epoxy resin or an acrylate with respect to 100 parts by weight of the main component.

The optical waveguide of the present invention can form a core layer of a specified width and thickness on the lower cladding layer, and a film-shaped optical waveguide can be obtained by a method of providing an upper cladding layer or the like as a cover layer. The laminate for the optical-electric composite wiring board of the present invention is provided with a lower cover layer on the flexible copper-clad laminate, and a core layer of a specified thickness and width is formed on the lower cover layer, and the upper cover is covered by the cover. The method of layer etc. can be obtained. Moreover, the optical-electric composite wiring board can be obtained by circuit-processing the copper foil of the laminated body of the photovoltaic-electric-complex wiring board of this invention.

Next, a method of forming an optical waveguide will be described with reference to the flowcharts shown in Figs.

For example, a composition solution (referred to as a coating material for a covering material) as a covering material is applied onto a substrate 1 such as glass, and is pre-dried at a temperature of 50 to 120 ° C, and the obtained film is peeled off from the substrate. Further, the peeled film is temporarily adhered to the substrate by a heat-resistant tape or the like, and then heat-treated at a temperature of 120 to 200 ° C for 20 to 120 minutes to be cured to obtain a film-like lower cover layer 2 ( FIG. 1 ).

Next, as shown in FIG. 2, the composition of the core material (referred to as a solution for core material) is formed into a specified core layer shape by screen printing or the like as shown in FIG. 2, and is at a temperature of 120 to 200 ° C. Heat treatment for 20 to 120 minutes to harden the core layer 3. The core material forming the core layer has a higher refractive index than the cover material forming the lower cover layer 2.

Alternatively, as shown in FIG. 3, the core material solution 3' is applied to the lower cover layer 2, and is pre-dried at a temperature of 50 to 120 ° C, and thereafter, a mask 4 forming a specified mask pattern is used. The core layer 3 can also be formed by selectively exposing the unexposed portion to an aqueous alkali solution and heat-treating at a temperature of 120 to 200 ° C for 20 to 120 minutes to harden it.

Further, a film obtained by pre-drying a core material composition comprising a photosensitive base-containing polyimide resin is laminated on the upper cover layer 2, and is selectively formed by exposure, development, and hardening. Core layer.

Next, as shown in FIG. 4, on the core layer, the same covering material for forming the lower cladding layer 2 is coated with a solution, and heat-treated at a temperature of 120 to 200 ° C for 20 to 120 minutes to form a hardened layer. The upper cover layer 5 is then peeled off from the substrate 1 to obtain the film-shaped optical waveguide 6 of the present invention. The lower cover layer 2 and the upper cover layer 5 are made of the same material, and the two are connected by a portion having no core layer, so that they are integrated, and the boundary cannot be determined in the drawing.

Further, the pre-dried film obtained by forming the lower cladding layer is laminated on the core layer, and heat-treated at a predetermined temperature to form an upper cladding layer.

Since most of the coating layers constituting the optical waveguide thus obtained are made of a flexible material, the amount of light transmission loss of the light transmission index after the tens of thousands of times of bending treatment is repeated, and it is expected to be extremely low to underfill. A value of around 0.02 dB.

Next, a method for producing a laminate for a flexible optical-electric composite wiring according to the present invention will be described with reference to FIGS. 5 and 6. The flexible wiring laminate 7 has a copper foil layer 8 and a polyimide layer 9. On the polyimide layer 9, the lower cover layer 2 is provided in the same manner as above, and the core layer 3 is formed next, and the upper cover layer 5 is provided in such a manner as to cover the laminate 10 for the photo-electric composite wiring. The example of FIG. 5 is a method of forming the core layer 3 by exposure, development, thermosetting, or the like to form a predetermined core layer shape, and FIG. 6 is a method of forming the core layer 3 into a designated core layer shape by screen printing or the like.

Further, the film-shaped optical waveguide 6 obtained by the optical waveguide forming method is passed through an adhesive layer as needed, and is adhered to the surface of the polyimide layer 9 of the flexible wiring laminate 7 to obtain light. The laminate 10 for electric composite wiring.

[Examples]

The invention will now be described in further detail by way of examples. In addition, the abbreviation used in this Example is the following compound.

BTDA: 3,3',4,4'-benzophenonetetracarboxylic dianhydride ODPA: 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride DSDA: 3,3',4,4 '-Diphenylfluorene tetracarboxylic dianhydride BPDA: 3,3',4,4'-biphenyltetracarboxylic dianhydride BAPP: 2,2-bis[4-(4-aminophenoxy)phenyl] Propane DAPE: diaminodiphenyl ether DVDABP: 2,2'-divinyl-4,4'-diaminobiphenyl PSX-1: polydimethyl methoxyalkylene diamine having a number average molecular weight of about 750 In the diamine residue portion of the general formula (2), R ₄ is -CH ₃ , R ₃ is -(CH ₂ ) ₃ -, m is 7-8) PSX-2: vinyl group having a number average molecular weight of about 850 Polydimethyl methoxy hydride diamine (in the diamine residue portion of the general formula (2), R ₄ is -CH ₃ or -CH=CH ₂ , and R ₃ is -(CH ₂ ) ₃ -, m It is 7~8, with an average of 1 vinyl in one molecule. BAFL: 9,9-bis(4-aminophenyl)-9H-芴DMAC: dimethylacetamide EOCN: cresol novolac type ring Oxygen resin (epoxy equivalent: 191 g/eq) BrenS: brominated novolac type epoxy resin (epoxy equivalent: 275 g/eq) SR-350: trimethylolpropane trimethacrylate (manufactured by Nippon Kasei Co., Ltd.) Irg369: Photopolymerization initiator (manufactured by Ciba Geigy)

Manufacturing example 1

35.8 grams of DSDA (0.1 mole) was dissolved in DMA grams of DMAC in a reactor equipped with a nitrogen injection tube, and the reactor was ice-cooled. 60 g (0.08 mol) of PSX-1 was dropped therein over 1 hour under a nitrogen atmosphere. Furthermore, 8.2 g (0.02 mol) of BAPP was added, and after the completion of the dropwise addition, the temperature in the reactor was returned to room temperature, and the mixture was stirred under a nitrogen atmosphere for 5 hours to obtain a polyamine resin solution containing a siloxane. . The viscosity of the dimethylacetamide solution (resin concentration: 25.1% by weight) of the polyoxyphthalic acid resin containing the decyl alkoxide at 25 ° C was 2500 cPa when measured by an E-type viscometer. s. Furthermore, the solution of the resin composition was obtained by mixing 20 parts by weight of EOCN with a polyphthalic acid resin solution containing a decyl alkoxide (100 parts by weight based on a polyphthalic acid resin containing a decyl alkane).

Manufacturing example 2~3

Using a resin material shown in Table 1 in the same manner as in Production Example 1, a polyoxyphthalic acid resin solution containing a halogenated alkane was obtained. Further, 30 parts by weight of BrenS, 5 parts by weight of aerosol, 5 parts by weight of cerium oxide sol, and 10 parts by weight of antifoaming agent are blended with respect to 100 parts by weight of the resin in the polyoxerine resin solution containing a siloxane. A solution of the resin composition was obtained.

Manufacturing example 4~6

Using a resin material shown in Table 1 in the same manner as in Production Example 1, a polyoxyphthalic acid resin solution containing a halogenated alkane was obtained. Further, a solution of the photosensitive resin composition was obtained by adding the additive shown in Table 1 to 100 parts by weight of the resin of the obtained polyoxyphthalic acid resin solution containing a siloxane.

Manufacturing example 7~8

The resin raw material and the additive shown in Table 1 were used in the same manner as in Production Example 1 except that the oxirane diamine was not used, and the reaction and the mixture were carried out to obtain a solution of the resin composition.

Manufacturing Example 9

Using a resin material shown in Table 1 in the same manner as in Production Example 1, a polyoxyphthalic acid resin solution containing a halogenated alkane was obtained. Further, a solution of the photosensitive resin composition was obtained by adding the additive shown in Table 1 to 100 parts by weight of the resin of the obtained polyoxyphthalic acid resin solution containing a siloxane.

A solution of each of the resin compositions obtained as described above was thinned under the conditions specified below.

Manufacturing Example 10

On the glass substrate, the resin composition solutions obtained in Production Examples 1 to 3 and 7 to 8 were applied by a bar coater, and predried at 120 ° C for 20 minutes to peel off the obtained film from the glass substrate. Further, the peeled film was attached to a glass substrate using a heat-resistant tape (manufactured by Capton), and then cured at 180 ° C for 30 minutes to form a film having a thickness of 20 μm.

Manufacturing Example 11

The photosensitive resin composition solution obtained in Production Examples 4 to 6 and 9 was applied on a glass substrate by a bar coater, and predried at 120 ° C for 20 minutes to peel off the obtained film from the glass substrate. Further, the peeled film was attached to a glass substrate using a heat-resistant tape (manufactured by Capton), and then the film was irradiated with UV light using an exposure machine (Hitech, high-pressure mercury lamp), and cured at 180 ° C for 30 minutes to form a film having a thickness of 20 μm.

The characteristics of the film obtained by the above method were evaluated as follows.

1) Refractive index: Each film (20 μm thick) was measured for refractive index at 630 nm. Further, the refractive index after bending treatment of 100,000 times under the conditions of a bending angle of 170° and a number of revolutions of 60 rpm was measured using a bending tester.

2) Light transmittance: Each film (20 μm thick) was measured for light transmittance at 850 nm. Further, the light transmittance after bending treatment in the same manner as in the measurement of the refractive index of 1) was measured.

3) Tg: Dynamic viscoelasticity measurement of each film was carried out, and the peak temperature of tan δ was regarded as Tg.

4) Elasticity: The tensile modulus of each film was measured by a tensile tester Autograph AG-500A (manufactured by Shimadzu Corporation).

5) Water absorption rate: The water absorption rate of each film was measured in accordance with JIS specifications.

The type and amount of the resin raw material, the solution viscosity of the polyaminic acid resin, the type and amount of the additive in the polyamic acid resin solution (relative to 100 parts by weight of the resin in the polyaminic resin solution) and The film properties are shown in Table 1.

As shown in Table 1, the optical waveguide material composed of a decane-modified polyimine resin can control the refractive index difference over a wide range via the content of the decane component, has high light transmittance, and is repeatedly bent. The change in refractive index and light transmittance before and after treatment is small. On the other hand, an optical waveguide material composed of a polyimine resin which does not contain a decane component has a small refractive index difference and a low light transmittance, and thus is not suitable as an optical waveguide.

Example 1

A solution of the resin composition obtained in Production Example 1 was applied as a coating layer on a glass substrate, coated with a screen printing machine, pre-dried at 120 ° C for 20 minutes, and the obtained film was peeled off from the glass substrate. Further, the peeled film was attached to a glass substrate using a heat-resistant tape (manufactured by Capton), and then cured at 180 ° C for 30 minutes to form a 20 μm thick lower cover layer.

Next, the film-like cover layer was attached to a screen printing machine, and the resin composition solution obtained in Production Example 2 was used as a core layer to form a printing plate having a specified printing pattern (a pattern of a core layer). The coating layer was coated at the designated layer, and then hardened at 180 ° C for 30 minutes to form a core layer (size: film thickness 20 μm, width 100 μm) on the cover layer.

Next, on the core layer, a solution of the same resin composition used for forming the lower cover layer was applied by a screen printing machine, and hardened at 180 ° C for 30 minutes to form a 20 μm thick upper cover layer. Thereafter, the heat-resistant adhesive tape temporarily adhered was peeled off to obtain a film-shaped optical waveguide.

Example 2

A film-shaped optical waveguide was obtained in the same manner as in Example 1 except that the resin composition solution obtained in Production Example 3 was used as the core layer.

Example 3

The resin composition solution obtained in Production Example 1 was applied onto a glass substrate by a screen printing machine, pre-dried at 120 ° C for 20 minutes, and the obtained film was peeled off from the glass substrate. Further, the peeled film was attached to a glass substrate using a heat-resistant tape (manufactured by Capton), and then cured at 180 ° C for 30 minutes to form a 20 μm thick lower cover layer.

Next, the photosensitive resin composition solution obtained in Production Example 4 was applied onto a film by a screen printing machine, pre-dried at 120 ° C for 10 minutes, and thereafter, a mask which formed the specified mask pattern was used. Exposure was performed using an exposure machine (Hitech, high pressure mercury lamp). Thereafter, development was carried out at 30 ° C for 150 seconds using a 1% aqueous sodium carbonate solution, and heat-treated at a temperature of 180 ° C for 30 minutes to harden it to form a core layer.

Next, on the core layer, the resin composition solution obtained in Production Example 1 was applied, and cured at 180 ° C for 30 minutes to form a 20 μm thick upper cover layer. Thereafter, the heat-resistant adhesive tape temporarily adhered was peeled off to obtain a film-shaped optical waveguide.

Example 4

A film-shaped optical waveguide was obtained in the same manner as in Example 3 except that the resin composition solution obtained in Production Example 5 was used as the core layer.

Example 5

A film-shaped optical waveguide was obtained in the same manner as in Example 3 except that the resin composition solution obtained in Production Example 6 was used as the core layer.

Example 6

A laminate of a flexible printed wiring board (a flexible copper-clad laminate made of Nippon Steel Chemical Co., Ltd.; ESPANEX single-sided type: polyimide film thickness: 25 μm, copper foil 18 μm) The resin composition solution obtained in Production Example 1 was applied by a screen printing machine, pre-dried at 120 ° C, and further cured at 180 ° C for 30 minutes to form a 20 μm thick lower cover layer.

Next, the resin composition solution obtained in Production Example 2 was applied to a designated portion on the cover layer by forming a printing plate of a designated printing pattern, and cured at 180 ° C for 30 minutes to form a core layer on the cover layer. : film thickness 20 μm, width 100 μm).

Next, on the core layer, the resin composition solution obtained in Production Example 1 was applied, and cured at 180 ° C for 30 minutes to form a 20 μm thick upper cladding layer, and the optical waveguide was formed on the flexible substrate. A laminate for a light-electric composite wiring board.

Example 7

The resin composition solution obtained in Production Example 1 was applied onto a polyimide surface of the laminate for the flexible printed wiring board, and was applied by a screen printing machine, pre-dried at 120 ° C, and hardened at 180 ° C. A 20 μm thick lower cover layer was formed for 30 minutes.

Next, the photosensitive resin composition solution obtained in Production Example 4 was applied onto the lower cover layer, and pre-dried at 120 ° C for 10 minutes. Thereafter, a mask having a specified mask pattern was used and an exposure machine was used ( Hitech, high pressure mercury lamp) is exposed. The unexposed portion was developed using a 1% sodium carbonate aqueous solution at 150 ° C for 150 to 200 seconds, and heat-treated at a temperature of 180 ° C for 30 minutes to form a core layer (size: film thickness: 20 μm, width: 100 μm).

Next, on the core layer, the resin composition solution obtained in Production Example 1 was applied, and cured at 180 ° C for 30 minutes to form a 20 μm thick upper cladding layer, and the optical waveguide was formed on the flexible substrate. A laminate for a light-electric composite wiring board.

Example 8

In the same manner as in the seventh embodiment, except that the photosensitive resin composition solution of Production Example 9 was used instead of the photosensitive resin composition of Production Example 4, the flexible optical-electricity in which the optical waveguide was formed on the flexible substrate was obtained in the same manner. A laminate for a composite wiring board.

[Industrial Applicability]

When the optical waveguide formed of the polyimide resin and the flexible copper-clad laminate are combined, the flexible optical-electric composite wiring board having high reliability and excellent reliability can be put to practical use.

1. . . Substrate

2. . . Lower cover

3. . . Core layer

4. . . (light) cover

5. . . Upper cover

6. . . Optical waveguide

7. . . Flexible wiring laminate

8. . . Copper foil layer

9. . . Polyimine layer

10. . . Laminate for light-electric composite wiring board

Fig. 1 is a flow chart showing the manufacture of an optical waveguide.

Fig. 2 is a flow chart showing the manufacture of an optical waveguide.

Fig. 3 is a flow chart showing the manufacture of an optical waveguide.

Fig. 4 is a flow chart showing the manufacture of an optical waveguide.

Fig. 5 is a flow chart showing the manufacture of a laminate for an optical-electric composite wiring board.

Fig. 6 is a flow chart showing the manufacture of a laminate for an optical-electric composite wiring board.

2. . . Lower cover

3. . . Core layer

4. . . (light) cover

5. . . Upper cover

7. . . Flexible wiring laminate

8. . . Copper foil layer

9. . . Polyimine layer

10. . . Laminate for light-electric composite wiring board

Claims (7)

A flexible optical waveguide having a cover layer and a core layer, wherein the cover layer is a polyimine having a constituent unit represented by the following general formulas (1) and (2). The resin is formed of an optical waveguide material as a main component, and the core layer is a polyamic acid resin having a constituent unit represented by the following general formula (6) and general formula (7) and a monomer having an unsaturated bond and a photopolymerization initiator is formed of an optical waveguide material containing, as a main component, a resin obtained by curing a photosensitive resin composition as a main component. However, Ar ₁ and Ar ₂ are independently a tetravalent aromatic group represented by the formula (3), and Ar ₃ is a divalent aromatic group represented by the formula (4) or the formula (5), and R ₁ is independently represented. The carbon number is 1 to 8 one-valent hydrocarbon groups, R ₃ is a divalent hydrocarbon group independently representing 2 to 6 carbon atoms, R ₄ is an independently represented carbon number of 1 to 6 one-valent hydrocarbon groups, and X and Y are independent representations. a bond or a divalent group selected from 1 to 15 carbon atoms, O, S, CO, SO ₂ or CONH, m is a number from 1 to 50, and n is an integer representing 0 to 4 independently. p and q are the molar ratios of the respective constituent units, p is in the range of 0.05 to 0.99, and q is in the range of 0.01 to 0.95; However, Ar ₁ and Ar ₂ , Ar ₃ , R ₃ and R ₄ have the same meanings as in the above general formulas (1) and (2), but R _{1 in} Ar ₃ or R ₄ in the general formula (7) At least a portion of it is an alkenyl or alkenylphenyl group. The optical waveguide of claim 1, wherein the core layer and the cover layer are formed using optical waveguide materials as described in claim 1 in which the refractive indices are different from each other. The optical waveguide of claim 1, wherein the refractive index difference Δ of the optical waveguide material forming the core layer and the cladding layer is 0.01 or more. The optical waveguide of claim 1, wherein the optical waveguide has a core layer and a cover layer surrounding the core layer, and the cover layer has a lower refractive index than the core layer. The optical waveguide of claim 1, wherein the polyamidene resin has an elastic modulus in the range of 0.2 to 3.0 GPa. A laminate for an optical-electric composite wiring board, characterized in that the optical waveguide according to any one of the first to fifth aspects of the invention is formed on a flexible copper-clad laminate. An optical-electric composite flexible wiring board characterized in that the optical waveguide according to any one of the first to fifth aspects of the invention is formed on a flexible wiring board.