JPWO2008007673A1 - Flexible optical waveguide and laminate for opto-electric composite wiring board - Google Patents

Abstract

By combining an optical waveguide made of polyimide resin with a flexible copper-clad laminate, a highly reliable flexible opto-electric composite wiring board with excellent flexibility is obtained. This optical waveguide has a clad layer and a core layer, and the clad layer is formed using an optical waveguide material mainly composed of a siloxane-modified polyimide resin. The core layer is formed using an optical waveguide material having a refractive index different from that of the cladding layer. As the optical waveguide material for the core layer, a material mainly composed of a siloxane-modified polyimide resin is suitable. The optical waveguide material of the core layer can easily form a desired pattern by using a resin composition containing a photosensitive resin. Also, the opto-electric composite wiring board can be obtained by providing a clad layer and a core layer on a flexible printed wiring board so that the core layer is surrounded by the clad layer.

Description

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

  In recent years, the progress of optical communication technology capable of high-speed and large-capacity data communication has been remarkable, and the optical communication network is continuing to expand. Optical communication technology is currently used for long-distance communication and medium-distance communication within a region, but in the future, optical signal transmission within and between devices will be applied.

  In portable devices and small devices, various parts are densely arranged, so wiring must be performed so as to sew a narrow gap between the parts. Therefore, flexible printed wiring boards are widely used as electrical wiring. Similarly, an optical wiring board (optical circuit wiring board) made of a flexible optical waveguide is desired in order to transmit an optical signal at a short distance such as inside or between these devices.

  Therefore, development of a flexible optical-electric composite wiring board in which an optical wiring board made of these flexible optical waveguides and an electric wiring board made of a flexible printed wiring board are integrated is expected.

Several optical waveguide materials used for opto-electric composite wiring boards have been proposed.
JP 2006-22317 JP 2004-149724 A JP 2005-43497 A

  Patent Document 1 teaches an optical waveguide formed by curing a photocurable epoxy resin film and a thermosetting epoxy resin film. Since this optical waveguide material has a crosslinked structure formed by a curing reaction, the flexibility is insufficient, and it is particularly difficult to apply it to a portion requiring repeated bending resistance such as a hinge portion of a mobile phone or the like. . In addition, there is a concern that the properties under high temperature and high humidity conditions deteriorate due to the high water absorption characteristic of epoxy resins.

  Patent Document 2 proposes an optical waveguide using a polyimide resin. Since this optical waveguide material contains fluorine in the polyimide structure, there is a concern that when it is combined with a flexible printed wiring board, it has poor adhesion at the interface with the flexible board. Fluorine-based materials are generally expensive, and are disadvantageous in terms of cost when put to practical use. Patent Document 3 proposes an optical waveguide having two upper cladding layers, but is inferior in flexibility because it is an inorganic material.

  The present invention has been made in view of the above problems, and is made of a flexible (low elasticity) and low water-absorbing polyimide resin so that a flexible opto-electric composite wiring board can be put into practical use. An object of the present invention is to provide an optical waveguide and a laminate for an optical-electric composite wiring board that includes the optical waveguide and has excellent repeated flexibility and reliability.

  The present inventors have found that the above object can be achieved by using a polyimide resin having a specific structure, and have completed the present invention.

（但し、Ar₁及びAr₂は独立に式(3)で表される4価の芳香族基を示し、Ar₃は式(4)又は式(5)で表される2価の芳香族基を示し、R₁は独立に炭素数1〜6の1価の炭化水素基を示し、R₃は独立に炭素数2〜6の2価の炭化水素基を示し、R₄は独立に炭素数1〜6の1価の炭化水素基を示し、X及びYは独立に単結合又は炭素数1〜15の2価の炭化水素基、O、S、CO、SO₂若しくはCONHから選ばれる2価の基を示し、mは1〜50の数を示し、nは独立に0〜4の整数を示し、p及びqは各構成単位の存在モル比を示し、pは0.05〜0.99の範囲であり、qは0.01〜0.95の範囲である）That is, the present invention uses an optical waveguide material mainly composed of a polyimide resin having a structural unit represented by the following general formulas (1) and (2) in an optical waveguide having a cladding layer and a core layer. It is a flexible optical waveguide characterized by being formed.

(However, Ar ₁ and Ar ₂ independently represent a tetravalent aromatic group represented by the formula (3), Ar ₃ represents a divalent aromatic group represented by the formula (4) or the formula (5) R ₁ independently represents a monovalent hydrocarbon group having 1 to 6 carbon atoms, R ₃ independently represents a divalent hydrocarbon group having 2 to 6 carbon atoms, and R ₄ independently represents a carbon number. 1 to 6 represents a monovalent hydrocarbon group, X and Y are independently a single bond or a divalent hydrocarbon group having 1 to 15 carbon atoms, a divalent group selected from O, S, CO, SO ₂ or CONH. Wherein m is a number from 1 to 50, n is independently an integer from 0 to 4, p and q are the molar ratio of each constituent unit, and p is in the range of 0.05 to 0.99. Q is in the range of 0.01 to 0.95)

The optical waveguide of the present invention preferably satisfies any one or more of the following.
1) The core layer is formed using the optical waveguide material having a refractive index different from that of the cladding 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 has a core layer and a cladding layer covering the periphery of the core layer, and the refractive index of the cladding layer is lower than that of the core layer.

  The present invention also provides an optical-electric composite wiring board or an optical-electric composite flexible wiring board, wherein the optical waveguide is formed on a flexible copper-clad laminate or on a flexible wiring board. It is. Here, a flexible copper clad laminated board means the laminated body before circuit formation, and a flexible wiring board means the wiring board in which the circuit was formed. The circuit can be formed by etching the copper foil layer of the flexible copper clad laminate.

  The optical waveguide of the present invention has a core layer and a cladding layer. The clad layer is formed using an optical waveguide material whose main component is a polyimide resin having a structural unit represented by the general formulas (1) and (2) (hereinafter also referred to as a siloxane-modified polyimide resin).

  The siloxane-modified polyimide resin used in the present invention has structural units represented by the above general formulas (1) and (2).

In the general formulas (1) and (2), Ar ₁ and Ar ₂ independently represent a tetravalent aromatic group represented by the formula (3), and Ar ₃ is represented by the formula (4) or the formula (5). R ₃ independently represents a divalent hydrocarbon group having 2 to 6 carbon atoms, and R ₄ independently represents a monovalent hydrocarbon group having 1 to 6 carbon atoms. , M represents a number from 1 to 50. Here, when a plurality of R _{3 s} , R _{4 s,} etc. are present in one structural unit, they may be independently changed within the above ranges. Further, when a plurality of structural units are present in one molecule, Ar ₁ , Ar ₂ , Ar ₃ , and R _{3 to} R ₄ may each independently change within the above range. Further, when the siloxane-modified polyimide resin is composed of a plurality of molecules, it may be independently changed within the above range for each molecule. The same applies to Y and X, R ₁ and n described below.

In the formulas (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. And R ₁ independently represents a monovalent hydrocarbon group having 1 to 6 carbon atoms, and n represents an integer of 0 to 4. As described above, Ar ₃ may be a divalent aromatic group represented by the formula (4) or a divalent aromatic group represented by the formula (5). Or you may have both in a some molecule | numerator.

Ar ₁ and Ar ₂ are tetravalent groups represented by the formula (3), but polyimide resins are usually synthesized by reacting aromatic tetracarboxylic acids such as aromatic tetracarboxylic dianhydrides with diamines. Therefore, it can be called the residue of Ar ₁ and Ar ₂ aromatic tetracarboxylic acids. Thus, Ar _{1 to} Ar ₂ are understood by describing the aromatic tetracarboxylic acids used in the synthesis. However, the siloxane-modified polyimide resin used in the present invention is not limited to the polyimide resin obtained by such a synthesis method. 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 represents a single bond, a divalent hydrocarbon group having 1 to 15 carbon atoms, a divalent group selected from O, S, CO, SO ₂ or CONH. Preferably, it represents a single bond or a divalent group selected from O, CO and SO ₂ . Preferred examples of the divalent hydrocarbon group include an alkylene group having 1 to 6 carbon atoms (which means an alkylidene group) and a phenylene group.

Aromatic tetracarboxylic acids that give preferable Ar ₁ and Ar ₂ will be described as representatives of acid dianhydrides.

  Specifically, 2,2 ′, 3,3′-, 2,3,3 ′, 4′- or 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride, 3,3 ′, 4,4'-biphenyltetracarboxylic dianhydride, 2,3 ', 3,4'-biphenyltetracarboxylic dianhydride, 2,2', 3,3'-biphenyltetracarboxylic dianhydride, 3 , 3 ', 4,4'-diphenylsulfone tetracarboxylic anhydride, 3,3', 4,4'-diphenyl ether tetracarboxylic dianhydride, 2,3 ', 3,4'-diphenyl ether tetracarboxylic anhydride Preferred examples include anhydrides and bis (2,3-dicarboxyphenyl) ether dianhydrides. Also 3,3``, 4,4 ''-, 2,3,3``, 4 ''-or 2,2 '', 3,3 ''-p-terphenyltetracarboxylic dianhydride 2,2-bis (2,3- or 3,4-dicarboxyphenyl) -propane dianhydride, bis (2,3- or 3.4-dicarboxyphenyl) methane dianhydride, bis (2,3- Alternatively, 3,4-dicarboxyphenyl) sulfone dianhydride and 1,1-bis (2,3- or 3,4-dicarboxyphenyl) ethane dianhydride are also included.

Other tetracarboxylic acids can be used along with the aromatic tetracarboxylic acids that provide Ar ₁ and Ar ₂ . When other tetracarboxylic acids are used, the amount used is 50 mol% or less, preferably 20 mol% or less, based on the total aromatic tetracarboxylic acids.

  Such other tetracarboxylic acids are exemplified as acid dianhydrides. Pyromellitic dianhydride, 2,3,5,6-cyclohexane dianhydride, 2,3,6,7-naphthalene tetracarboxylic dianhydride, 1,2,5,6-naphthalene tetracarboxylic dianhydride 1,4,5,8-naphthalenetetracarboxylic dianhydride, 4,8-dimethyl-1,2,3,5,6,7-hexahydronaphthalene-1,2,5,6-tetracarboxylic Acid 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-perylene-tetracarboxylic dianhydride, cyclopentane-1,2,3,4-tetracarboxylic dianhydride, pyrazine-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-tetracarboxylic dianhydride, 2,3,6,7-anthracene A tetracarboxylic dianhydride etc. can also be mentioned.

In the general formula (1), the divalent aromatic group represented by Ar ₃ can be said to be a diamine residue. Therefore, Ar ₃ or X, R ₁ and n in formula (4) and formula (5) are understood by describing the diamine used in the synthesis. Further, the structural unit represented by the general formula (1) may be composed of a plurality of types of structural units having different divalent aromatic groups.

X can be the same as Y above, but may be different. Examples of X include those described in Y above. Preferably, it is a single bond or a divalent group selected from O, S, CO, SO _2, CONH, CH ₂ , C (CH ₃ ) ₂ and a 9,9′-fluorenyl group. Further, the 9,9′-fluorenyl group is represented by the following formula.

In the divalent aromatic group containing X, R ₁ independently represents a monovalent hydrocarbon group having 1 to 6 carbon atoms, preferably an alkyl group having 1 to 6 carbon atoms, an alkenyl group, a cycloalkyl group, or It is a phenyl group. More preferably, they are a C1-C3 alkyl group, a vinyl group, or a phenyl group. n represents an integer of 0 to 4, preferably 0 to 2, and more preferably 0.

When Ar ₃ is a divalent aromatic group represented by the formula (5), a diamine that gives preferable Ar ₃ will be described.

  Specifically, 2,2-bis- [4- (4-aminophenoxy) phenyl] propane, 2,2-bis- [4- (3-aminophenoxy) phenyl] propane, bis [4- (4- Aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] sulfone, 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)] benzophenone, bis [4- (3-aminophenoxy) )] Benzophenone , Bis [4,4 '-(4-aminophenoxy)] benzanilide, bis [4,4'-(3-aminophenoxy)] benzanilide, 9,9-bis [4- (4-aminophenoxy) phenyl] fluorene 9,9-bis [4- (3-aminophenoxy) phenyl] fluorene and the like.

When Ar ₃ is a divalent aromatic group represented by the formula (4), preferred diamines that give Ar ₃ will be described.

  Specifically, 4,4'-methylenedi-o-toluidine, 4,4'-methylenedi-2,6-xylidine, 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'-diamino Diphenyl sulfide, 3,3'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 3, 4 ' -Diaminodiphenyl ether, benzidine, 3,3'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethoxybenzidine, 4,4 ''-diamino-p-terphenyl, 3,3``-Diamino-p- Butylphenyl, 9,9-bis (4-aminophenyl) -9H- fluorene, and the like.

  Among these, 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-fluorene, 1,3-bis (4-aminophenoxy) benzene (TPE-R) and the like are preferably used. Other aromatic diamines other than those described above can be used in combination in small amounts (50 mol% or less, preferably 20 mol% or less). Further, a diamine substituted with an unsaturated group such as a vinyl group such as 2,2′-divinyl-4,4′-diamino-biphenyl is also preferably used.

  Examples of such other aromatic diamines include m-phenylenediamine, p-phenylenediamine, 2,6-diaminopyridine, 1,4-bis (4-aminophenoxy) benzene, and 1,3-bis (4-amino). Phenoxy) benzene, 4,4 '-[1,4-phenylenebis (1-methylethylidene)] bisaniline, 4,4'-[1,3-phenylenebis (1-methylethylidene)] bisaniline, bis (p- Aminocyclohexyl) methane, bis (p-β-amino-t-butylphenyl) ether, bis (p-β-methyl-δ-aminopentyl) benzene, p-bis (2-methyl-4-aminopentyl) benzene, p-bis (1,1-dimethyl-5-aminopentyl) 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, Examples thereof include p-xylylenediamine, 2,6-diaminopyridine, 2,5-diaminopyridine, 2,5-diamino-1,3,4-oxadiazole, piperazine and the like.

In the general formula (2), the divalent group containing a siloxane structure whose terminal is R ₃ can be referred to as a diamine residue. Therefore, a divalent group containing a siloxane structure or R ₃ , R ₄ and m in the general formula (2) can be understood by explaining a diamine containing a siloxane structure used in the synthesis as described above. Further, the structural unit represented by the general formula (2) may be composed of a plurality of types of structural units having different divalent groups containing the siloxane structure.

In the divalent group containing the siloxane structure of the general formula (2), m represents a number of 1 to 50, preferably 5 to 30. If this value is less than 1, the reduction in elastic modulus (flexural properties) 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 properties are lowered. To do. R ₃ represents a divalent hydrocarbon group having 2 to 6 carbon atoms, preferably an alkylene group having 2 to 6 carbon atoms. R ₄ represents an alkyl group having 1 to 6 carbon atoms or a phenyl group, preferably a methyl group or a phenyl group.

  Examples of the diamine having a preferable siloxane structure include ω, ω′-bis (2-aminoethyl) polydimethylsiloxane, ω, ω′-bis (3-aminopropyl) polydimethylsiloxane, ω, ω′-bis ( 4-aminophenyl) polydimethylsiloxane, ω, ω′-bis (3-aminopropyl) polydiphenylsiloxane, ω, ω′-bis (3-aminopropyl) polymethylphenylsiloxane, and the like.

  The siloxane-modified polyimide resin used in the present invention has structural units represented by general formulas (1) and (2), but the molar ratio q of the structural units represented by general formula (1) is 0.01 to 0.95. The range is preferably 0.5 to 0.8. The existence molar ratio p of the structural unit represented by the general formula (2) is 0.05 to 0.99, preferably 0.1 to 0.8. This existence molar ratio is within the above range even if the siloxane-modified polyimide resin is composed of only the structural units represented by the general formulas (1) and (2) or has other structural units. Preferably there is. In the case of having other structural units, p + q is 0.5 or more, preferably 0.8 or more. Further, p / (p + q) is preferably in the range of 0.1 to 0.8. The siloxane-modified polyimide resin used in the present invention has an elastic modulus of 0.2 to 3.0 Gpa, preferably 0.3 to 3.0 Gpa. The glass transition point (Tg) is 120 ° C. or higher, preferably 140 to 300 ° C.

  In the present invention, the core layer of the optical waveguide can be formed from siloxane-modified polyimide. However, it is advantageous to use a photosensitive material that can be patterned into an arbitrary shape by a photolithography method for the core layer. As such a photosensitive material, a photosensitive material mainly composed of a polyamic acid resin having structural units represented by the following general formulas (6) and (7), a monomer having an unsaturated bond, and a photopolymerization initiator is used. Resin obtained by curing the functional resin composition. The core layer of the optical waveguide of the present invention is also preferably a resin obtained by curing this photosensitive resin composition. Hereinafter, the resin obtained by curing is also referred to as a siloxane-modified cross-linked polyimide resin.

In the general formula (6) or the general formula (7), Ar ₁ , Ar ₂ , Ar ₃ , R ₃ and R ₄ have the same meanings as the general formulas (1) and (2). and Ar ₃ (formula (4) or a divalent aromatic group represented by the formula (5)) alkenyl part of R ₄ in R ₁ or the formula in (7) in (6), light It is desirable to impart polymerizability. The alkenyl _{group, CH 2 = CH-R 6} - has the group represented by, R ₆ is a direct bond, although an alkylene group or a phenylene group having 1 to 6 carbon atoms, reactive be straight bond This is preferable.

  As the monomer having an unsaturated bond, a monomer having photopolymerizability can be used, and acrylates such as polyfunctional acrylates are preferably exemplified in terms of transparency and refractive index. The amount used is 1 to 50 parts by weight, preferably 5 to 40 parts by weight per 100 parts by weight of the polyamic acid resin.

  The siloxane-modified polyimide resin can be synthesized by a known method. For example, it can be obtained by reacting one or more aromatic tetracarboxylic dianhydrides with two or more diamines in an approximately equimolar ratio in an organic solvent.

  An example of a method for producing a siloxane-containing polyimide resin will be described. First, an aromatic dianhydride is added to a solvent and dissolved. While stirring this, two or more diamines including siloxane diamine are gradually added under a nitrogen atmosphere and ice cooling. Then, a siloxane-containing polyamic acid resin solution can be obtained by stirring and reacting for 2 to 8 hours. The solvent needs to be inert to both the aromatic polyamic acid component and the siloxane component. Typical examples of this type of solvent include ether solvents such as diethylene glycol dimethyl ether (diglyme), diethylene glycol diethyl ether, and tetrahydrofuran, N, N-dimethylformamide, N, N-dimethylacetamide, and N-methyl-2-pyrrolidone. Amide solvents such as N-cyclohexyl-2-pyrrolidone and the like. One or more of these solvents can be used, but a solvent containing 10% by weight or more, preferably 30% by weight or more of diglyme solvent is suitable. It is.

  The obtained siloxane-containing polyamic acid resin is dehydrated and closed by heat treatment or treatment with a dehydrating agent to obtain a siloxane-containing polyimide resin. The heat treatment is performed, for example, by heating at 70 to 350 ° C. for 2 to 5 hours in a nitrogen atmosphere. More preferably, it is heated stepwise in a nitrogen atmosphere at 150 ° C. for 30 minutes, 250 ° C. for 30 minutes, and 320 ° C. for 1 hour. Further, by selecting a combination of a diamine and a tetracarboxylic acid anhydride, a polyimide resin soluble in a solvent can be obtained, and after dehydrating and ring-closing in advance, it may be dissolved in a solvent to form a solution. The solution viscosity (dimethylacetamide solution: concentration 25 wt%) of the siloxane-containing polyamic acid resin is preferably in the range of 2000 to 50000 cPa · s.

  At this time, a block-type or random-type siloxane-modified polyimide resin can be obtained by adjusting the order of addition of the reaction raw materials. Further, the refractive index of the siloxane-modified polyimide resin can be controlled by changing the amount of diamine containing a siloxane structure. That is, it has been found that when the amount of the diamine containing a siloxane structure is increased to increase the structural unit represented by the general formula (2) or the general formula (7), the refractive index decreases.

  The optical waveguide of the present invention has a core layer and a cladding layer. Usually, the cladding layer covers the periphery of the core layer, and the optical refractive index of the cladding layer is lower than that of the core layer. The optical waveguide of the present invention is formed from an optical waveguide material in which at least the cladding layer contains the siloxane-modified polyimide resin as a main component. The core layer may be formed from an optical waveguide material that does not contain the siloxane-modified polyimide resin, but is formed from this siloxane-modified polyimide resin, preferably a photosensitive polyamic acid resin that is a precursor thereof, in order to give flexibility. It may be formed from an optical waveguide material containing a siloxane-modified cross-linked polyimide resin as a main component of the resin. The siloxane-modified cross-linked polyimide resin refers to a polyimide resin produced by a reaction of the unsaturated group with a monomer or resin having another unsaturated group. In this case, a clad layer is formed from an optical waveguide material containing a siloxane-modified polyimide resin having a large molar ratio of the structural unit represented by the general formula (2), and a small amount of siloxane-modified polyimide resin or siloxane-modified cross-linked polyimide resin ( The calculation of the abundance ratio and the polyimide resin content is performed based on a photosensitive polyamic acid resin as a precursor) to form a core layer from an optical waveguide material. Hereinafter, the optical waveguide material forming the cladding layer is also referred to as a cladding material, and the optical waveguide material forming the core layer is also referred to as a core material. The refractive index of the optical waveguide material containing the siloxane-modified polyimide resin is preferably in the range of 1.45 to 1.65, and the refractive index difference Δ between the clad material and the core material is 0.01 or more, preferably 0.02 or more.

  The optical waveguide material containing the siloxane-modified polyimide resin of the present invention preferably contains 50 wt% or more, preferably 60 wt% or more of the siloxane-modified polyimide resin. Other compounding materials other than the siloxane-modified polyimide resin include transparent resins such as polyacrylates and epoxy resins, and fillers such as fine powdered silica.

  The photosensitive resin composition preferably used for forming the core layer is mainly composed of a polyamic acid resin having a structural unit represented by the general formula (6) and the general formula (7) and a photopolymerization initiator. A monomer such as acrylate (may be a polymerizable resin component), a sensitizer, a solvent, and the like. And the method of using this photosensitive resin composition (preferably its solution), photocuring and imidating this, and forming an optical waveguide is preferable. In this case, after photopolymerization, at least a part of the vinyl group of the siloxane-containing polyamic acid resin reacts with an unsaturated group of another monomer or resin, but the cured resin is referred to as a siloxane-modified crosslinked polyimide resin.

  Here, examples of the acrylate that can be used include 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxyethylacryloyl phosphate, 2-methoxyethoxyethyl acrylate, 2-ethoxyethoxyethyl acrylate, Tetrahydrofurfryl acrylate, phenoxyethyl acrylate, isodecyl acrylate, stearyl acrylate, lauryl acrylate, glycidyl acrylate, allyl acrylate, ethoxy acrylate, methoxy acrylate, N, N'-dimethylaminoethyl acrylate, benzyl acrylate, 2-hydroxyethyl acryloyl Phosphate, dicyclopentadienyl acrylate, dicyclopentadiene ethoxy acrylate, etc. Monoacrylate, dicyclopentenyl acrylate, dicyclopentenyloxyethyl acrylate, 1,3-butanediol 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, hydroxypivalate ester neopentyl glycol diacrylate, triethylene glycol diacrylate, bis ( Acryloxyethoxy) bisphenol A, bis (acryloxyethoxy) tetrabromobisph Enol A, tripropylene glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, tris (2-hydroxyethyl) isocyanate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, dipentaerythritol monohydroxypentaacrylate, etc. Functional acrylates can be used.

  In the photosensitive resin composition, the acrylate may be 1 to 50 parts by weight, preferably 5 to 40 parts by weight, based on 100 parts by weight of the siloxane-containing polyamic acid resin.

  Examples of the photopolymerization initiator include acetophenone, 2,2-dimethoxyacetophenone, p-dimethylaminoacetophenone, Michler's ketone, benzyl, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin n-propyl ether, benzoin isopropyl Ether, benzoin n-butyl ether, benzyl dimethyl ketal, thioxazone, 2-chlorothioxazone, 2-methylthioxazone, 2-hydroxy-2-methyl-1-phenyl-1-one, 1- (4-isopropylphenyl) Various photopolymerization initiators such as 2-hydroxy-2-methylpropan-1-one, methylbenzoylformate, 1-hydroxycyclohexyl phenyl ketone can be used. A preferable use amount of the photopolymerization initiator is 1 to 20 parts by weight, preferably 1 to 10 parts by weight with respect to 100 parts by weight of the siloxane-containing polyamic acid resin.

  It is also advantageous to add 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 siloxane-containing polyamic acid resin.

  When the siloxane-modified polyimide resin or the resin composition containing this as a main component is used as a solution, it is preferably used as a solution of a non-photosensitive polyamic acid resin composition in the same manner as the photosensitive resin composition. Moreover, these photosensitive or non-photosensitive resin compositions can adjust a viscosity etc. with various organic solvents. Examples of preferred organic solvents for use include triethylene glycol dimethyl ether (triglyme), diethylene glycol dimethyl ether (diglyme), dimethylacetamide, N-methylpyrrolidone, propylene glycol monomethyl ether acetate (pegmia), ethyl lactate, or a mixed solvent thereof. . The amount of the solvent used is preferably in the range of 10 to 100 parts by weight with respect to 100 parts by weight of the solid content of the resin composition. A resin composition that contains 10% by weight or more of a solvent and is liquid at room temperature is referred to as a varnish-like resin composition. Moreover, when the organic solvent used as a reaction solvent at the time of polyamic acid resin manufacture remains, it calculates as a solvent.

  In addition to the above, other resins as described below can be used in combination as long as the characteristics of the optical waveguide are not deteriorated. That is, the epoxy resin is not particularly limited as long as it has a plurality of epoxy groups in one molecule, and a commercially available liquid epoxy resin or solid epoxy resin can be used as appropriate. Specific examples of the epoxy resin include alicyclic epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, biphenyl type epoxy resin having biphenyl skeleton, naphthalene ring-containing epoxy resin, dicyclopentadiene Dicyclopentadiene type epoxy resin having a skeleton, phenol novolac type epoxy resin, cresol novolak type epoxy resin, triphenylmethane type epoxy resin, bromine-containing epoxy resin, aliphatic epoxy resin, triglycidyl isocyanurate, etc. One or more of these can be used. The addition amount is less than 40 parts by weight, preferably 30 parts by weight or less, with respect to 100 parts by weight of the polyimide resin or polyamic acid resin.

  In addition, if necessary, a resin solution containing the resin, resin composition or precursor resin for forming the optical waveguide material of the present invention can be provided with thixotropic material, inorganic filler, antifoaming agent, etc. It can also be added as long as it is not impaired. The optical waveguide material of the present invention formed from the resin composition is mainly composed of a siloxane-modified polyimide resin or a siloxane-modified cross-linked polyimide resin produced by imidization of the siloxane-modified polyimide precursor. Here, the main component means containing 50 wt% or more, preferably 60 wt% or more. More preferably, it is preferable to contain 15 to 35 parts by weight of epoxy resin or acrylate with respect to 100 parts by weight of the main component.

  In the optical waveguide of the present invention, a film-like optical waveguide can be obtained by a method of forming a core layer having a predetermined width and thickness on the lower cladding layer and providing an upper cladding layer so as to cover the core layer. The laminate for an optical-electric composite wiring board according to the present invention has a lower clad layer provided on a flexible copper clad laminate, a core layer having a predetermined width and thickness is formed on the lower clad layer, and an upper clad is formed so as to cover the core layer. It is obtained by a method such as providing a layer. Moreover, an opto-electric composite wiring board can be obtained by circuit processing the copper foil of the laminate for the opto-electric composite wiring board of the present invention.

The manufacturing flow sheet of an optical waveguide is shown. The manufacturing flow sheet of an optical waveguide is shown. The manufacturing flow sheet of an optical waveguide is shown. The manufacturing flow sheet of an optical waveguide is shown. The manufacturing flow sheet of the laminated board for optical-electrical composite wiring boards is shown. The manufacturing flow sheet of the laminated board for optical-electrical composite wiring boards is shown.

Explanation of symbols

1: substrate, 2: lower clad layer, 3: core layer, 4: (photo) mask, 5: upper clad layer, 6: optical waveguide, 7: laminate for flexible wiring, 8: copper foil layer, 9: polyimide Layer 10: Laminate for optical-electric composite wiring board

  Next, a method for forming an optical waveguide will be described with reference to FIGS.

  For example, a solution of a composition to be a clad material (called a clad material solution) is applied to a substrate 1 such as glass, and is appropriately pre-dried at a temperature of 50 to 120 ° C., and the resulting film is peeled from the substrate, The peeled film is temporarily fixed to the substrate again with a heat-resistant tape or the like, and then cured by a heat treatment at a temperature of 120 to 200 ° C. for 20 to 120 minutes to obtain a film-like lower cladding layer 2 (FIG. 1).

  Next, as shown in FIG. 2, a solution of a composition to be a core material (referred to as a core material solution) is formed into a predetermined core layer shape on the lower clad layer 2 by screen printing or the like, and a temperature of 120 to 200 ° C. The core layer 3 is obtained by curing by heat treatment for 20 to 120 minutes. The core material that forms the core layer has a higher refractive index than the clad material that forms the lower cladding layer 2.

Alternatively, as shown in FIG. 3, the core material solution 3 ′ is applied to the lower clad layer 2, preliminarily dried at a temperature of 50 to 120 ° C., and then a photomask 4 having a predetermined mask pattern is formed. The core layer 3 can also be formed by selectively exposing and developing the unexposed portion with an alkaline aqueous solution and curing it at a temperature of 120 to 200 ° C. for 20 to 120 minutes.
Also, a core layer is formed by laminating a film obtained by pre-drying a composition for a core material comprising a polyimide resin containing a photosensitive group on the lower clad layer 2, and selectively exposing, developing, and curing the film. You can also.

Next, as shown in FIG. 4, the same clad material solution as that used for forming the lower clad layer 2 is applied onto the core layer and cured by heat treatment at a temperature of 120 to 200 ° C. for 20 to 120 minutes. Then, the upper clad layer 5 is formed, and then peeled off from the substrate 1, whereby the film-like optical waveguide 6 of the present invention can be obtained. Since the lower clad layer 2 and the upper clad layer 5 are made of the same material and are in contact with each other at a portion where there is no core layer, they are integrated and the boundary is not obvious in the drawing.
The upper clad layer can also be formed by laminating a pre-dried film obtained when forming the lower clad layer on the core layer and heat-treating it at a predetermined temperature.

  Since the clad layer constituting the majority of the optical waveguide obtained in this way is a flexible material, light propagation loss is an index of light propagation after being repeatedly bent over tens of thousands of times. Is expected to be very low, less than 0.02dB.

Next, a method for manufacturing a flexible laminate for opto-electric composite wiring according to the present invention will be described with reference to FIGS. The flexible wiring laminate 7 has a copper foil layer 8 and a polyimide layer 9. On the polyimide layer 9, the lower clad layer 2 is provided in the same manner as described above, then the core layer 3 is formed, and the upper clad layer 5 is provided so as to cover the core layer 3. Get. The example of FIG. 5 is a method of forming the core layer 3 into a predetermined core layer shape by exposure, development, thermosetting, etc., and the example of FIG. 6 is a method of forming the core layer 3 into a predetermined core layer shape by screen printing or the like. It is a method of forming.
Also, the film-like optical waveguide 6 obtained by the method for forming an optical waveguide is adhered to the surface of the polyimide layer 9 of the flexible wiring laminate 7 through an adhesive layer, if necessary, so that the opto-electric composite The wiring laminate 10 can also be obtained.

The following examples illustrate the present invention in more detail. The abbreviations used in this example indicate the following compounds:
BTDA: 3,3 ', 4,4'-benzophenone tetracarboxylic dianhydride
ODPA: 3,3 ', 4,4'-diphenyl ether tetracarboxylic dianhydride
DSDA: 3,3 ', 4,4'-diphenylsulfonetetracarboxylic 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'-diamino-biphenyl
PSX-1: Polydimethylsiloxane 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 —, and m is 7 to 8)
PSX-2: Vinyl group-containing polydimethylsiloxane diamine having a number average molecular weight of about 850 (in the diamine residue portion of the general formula (2), R ₄ is —CH ₃ or —CH═CH ₂ , R ₃ is — (CH ₂ ) _3- , m is 7-8, average 1 vinyl group per molecule)
BAFL: 9,9-bis (4-aminophenyl) -9H-fluorene
DMAC: Dimethylacetamide
EOCN: Cresol novolac type epoxy resin (epoxy equivalent 191g / eq)
BrenS: Brominated novolac epoxy resin (epoxy equivalent 275 g / eq)
SR-350: Trimethylolpropane trimethacrylate (Nippon Kayaku)
Irg369: Photopolymerization initiator (Ciba Geigy)

Production Example 1
In a reactor equipped with a nitrogen injection tube, 35.8 g (0.1 mol) of DSDA was dissolved in 290 g of DMAC, and the reactor was ice-cooled. To this, 60 g (0.08 mol) of PSX-1 was added dropwise over 1 hour under a nitrogen atmosphere. Further, 8.2 g (0.02 mol) of BAPP was added, and after completion of the dropwise addition, the temperature in the reactor was returned to room temperature and stirred for 5 hours in a nitrogen atmosphere to obtain a siloxane-containing polyamic acid resin solution. The viscosity at 25 ° C. of a dimethylacetamide solution (resin concentration: 25.1 wt%) of this siloxane-containing polyamic acid resin was measured with an E-type viscometer and found to be 2500 cPa · s. Furthermore, 20 parts by weight of EOCN was blended with the siloxane-containing polyamic acid resin solution (100 parts by weight as the siloxane-containing polyamic acid resin) to obtain a resin composition solution.

Production Examples 2-3
Using the same method as in Production Example 1, a siloxane-containing polyamic acid resin solution was obtained using the resin raw materials shown in Table 1. Furthermore, with respect to 100 parts by weight of the resin in the siloxane-containing polyamic acid resin solution, 30 parts by weight of BrenS, 5 parts by weight of Aerosil, 5 parts by weight of silica sol, and 10 parts by weight of an antifoaming agent are blended to obtain a resin composition solution. It was.

Production Examples 4-6
Using the same method as in Production Example 1, a siloxane-containing polyamic acid resin solution was obtained using the resin raw materials shown in Table 1. Furthermore, the additive shown in Table 1 was mix | blended with respect to 100 weight part of resin of the obtained siloxane containing polyamic acid resin solution, and the solution of the photosensitive resin composition was obtained.

Production Examples 7-8
A solution of the resin composition was obtained by performing the reaction and blending using the resin raw materials and additives shown in Table 1 using the same method as in Production Example 1 except that siloxane diamine was not used.

Production Example 9
Using the same method as in Production Example 1, a siloxane-containing polyamic acid resin solution was obtained using the resin raw materials shown in Table 1. Furthermore, the additive shown in Table 1 was mix | blended with respect to 100 weight part of resin of the obtained siloxane containing polyamic acid resin solution, and the solution of the photosensitive resin composition was obtained.

  The solution of each resin composition obtained as described above was formed into a film under the following predetermined conditions.

Production Example 10
The solution of the resin composition obtained in Production Examples 1 to 3 and 7 to 8 was applied on a glass substrate with a bar coater, preliminarily dried at 120 ° C. for 20 minutes, and the obtained film was peeled off from the glass substrate. It was. Further, the peeled film was attached on a glass substrate using a heat-resistant tape (manufactured by Kapton), and then cured at 180 ° C. for 30 minutes to form a 20 μm thick film.

Production Example 11
The solution of the photosensitive resin composition obtained in Production Examples 4 to 6 and 9 was applied on a glass substrate with a bar coater, preliminarily dried at 120 ° C. for 20 minutes, and the obtained film was peeled off from the glass substrate. . Furthermore, after the peeled film was attached on a glass substrate using a heat-resistant tape (manufactured by Kapton), the film was irradiated with UV light using an exposure machine (Hitech, high-pressure mercury lamp) at 180 ° C. for 30 minutes. Cured to form a 20 μm thick film.

The characteristics of the film obtained by the above method were evaluated as follows.
1) Refractive index: Refractive index at 630 nm of each film (thickness 20 μm) was measured. Furthermore, using a bending tester, the refractive index after performing 100,000 bending processes under the conditions of a bending angle of 170 ° and a rotational speed of 60 rpm was measured.
2) Light transmittance: The light transmittance at 850 nm of each film (thickness 20 μm) was measured. Further, the light transmittance after bending treatment performed by the same method as the refractive index measurement of 1) was measured.
3) Tg: The dynamic viscoelasticity of each film was measured, and the peak temperature of tan δ was defined as Tg.
4) Elastic modulus: The tensile elastic modulus of each film was measured with a tensile tester Autogragh AG-500A (manufactured by Shimadzu Corporation).
5) Water absorption: The water absorption of each film was measured according to JIS standards.

  Table 1 shows the types and amounts of the resin raw materials, the solution viscosity of the polyamic acid resin, the types and amounts of additives blended in the polyamic acid resin solution (parts by weight relative to 100 parts by weight of the resin in the polyamic acid resin solution), and film characteristics. .

  As shown in Table 1, the optical waveguide material comprising a siloxane-modified polyimide resin has a refractive index difference that can be controlled over a wide range and has a high light transmittance depending on the content of the siloxane component, and the refractive index and the refractive index before and after repeated bending treatments. The change in light transmittance is small. On the other hand, an optical waveguide material made of a polyimide resin not containing a siloxane component is not suitable as an optical waveguide because the difference in refractive index is small and the light transmittance is low.

Example 1
The solution of the resin composition obtained in Production Example 1 was applied on a glass substrate with a screen printer for forming a clad layer, 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 on a glass substrate using a heat-resistant tape (manufactured by Kapton), and then cured at 180 ° C. for 30 minutes to form a lower cladding layer having a thickness of 20 μm.
Next, this film-like clad layer was set in a screen printer, and a predetermined printing pattern (core layer pattern) was formed using the resin composition solution obtained in Production Example 2 as a core layer forming agent. A core layer (size: film thickness: 20 μm, width: 100 μm) was formed on the clad by applying to a predetermined location on the clad through a printing plate and then curing at 180 ° C. for 30 minutes.
Next, on this core layer, a solution of the same resin composition used for forming the lower clad layer was applied with a screen printer and cured at 180 ° C. for 30 minutes to form an upper clad having a thickness of 20 μm. . Thereafter, the heat-resistant tape temporarily fixed was peeled off to obtain a film-like optical waveguide.

Example 2
A film-like 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 for forming the core layer.

Example 3
The solution of the resin composition obtained in Production Example 1 was applied onto a glass substrate with a screen printer, preliminarily dried at 120 ° C. for 20 minutes, and the obtained film was peeled from the glass substrate. Further, the peeled film was attached on a glass substrate using a heat-resistant tape (manufactured by Kapton), and then cured at 180 ° C. for 30 minutes to form a lower cladding layer having a thickness of 20 μm.
Next, a solution of the photosensitive resin composition obtained in Production Example 4 was applied onto this film with a screen printer, preliminarily dried at 120 ° C. for 10 minutes, and then a photomask having a predetermined mask pattern formed thereon. It was exposed using an exposure machine (Hitech, high pressure mercury lamp). Thereafter, development was performed using a 1% aqueous sodium carbonate solution at 30 ° C. for 150 seconds, followed by curing at 180 ° C. for 30 minutes to form a core layer.
Next, a solution of the resin composition obtained in Production Example 1 was applied on the core layer and cured at 180 ° C. for 30 minutes to form an upper cladding layer having a thickness of 20 μm. Thereafter, the heat-resistant tape temporarily fixed was peeled off to obtain a film-like optical waveguide.

Example 4
A film-like 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 for forming the core layer.

Example 5
A film-like 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 for forming the core layer.

Example 6
A solution of the resin composition obtained in Production Example 1 on the polyimide surface of a laminate for flexible printed wiring board (flexible copper-clad laminate manufactured by Nippon Steel Chemical; ESPANEX single-sided type: polyimide film thickness 25 μm, copper foil 18 μm) Was applied using a screen printer, pre-dried at 120 ° C., and further cured at 180 ° C. for 30 minutes to form a lower cladding layer having a thickness of 20 μm.
Next, the solution of the resin composition obtained in Production Example 2 is applied to a predetermined location on the clad through a printing plate on which a predetermined printing pattern is formed, and is cured at 180 ° C. for 30 minutes. Then, a core layer was formed on the clad (size: film thickness 20 μm, width 100 μm).
Next, a solution of the resin composition obtained in Production Example 1 is applied onto this core layer, and cured at 180 ° C. for 30 minutes to form an upper cladding layer having a thickness of 20 μm. A laminate for a flexible optical-electric composite wiring board having a waveguide formed thereon was obtained.

Example 7
The solution of the resin composition obtained in Production Example 1 is applied to the polyimide surface of the laminate for the flexible printed wiring board using a screen printer, pre-dried at 120 ° C, and further cured at 180 ° C for 30 minutes. As a result, a lower cladding layer having a thickness of 20 μm was formed.
Next, the photosensitive resin composition solution obtained in Production Example 4 was applied to the lower clad surface, pre-dried at 120 ° C. for 10 minutes, and then used with a photomask on which a predetermined mask pattern was formed. It exposed using the exposure machine (Hitec, a high pressure mercury lamp). The unexposed area was developed using a 1% sodium carbonate aqueous solution at 30 ° C. for 150 to 200 seconds and cured by heat treatment at 180 ° C. for 30 minutes to form a core layer (size: film thickness 20 μm) , Width 100 μm).
Next, a solution of the resin composition obtained in Production Example 1 is applied on the core layer and cured at 180 ° C. for 30 minutes to form an upper cladding layer having a thickness of 20 μm. A laminate for a flexible optical-electric composite wiring board having a waveguide formed thereon was obtained.

Example 8
In Example 7, the same procedure was followed except that the solution of the photosensitive resin composition of Production Example 9 was used instead of the photosensitive resin composition of Production Example 4, and a flexible light having an optical waveguide formed on a flexible substrate- A laminate for an electrical composite wiring board was obtained.

Industrial applicability

  By combining an optical waveguide formed from a polyimide resin and a flexible copper-clad laminate, a highly reliable flexible opto-electric composite wiring board having excellent repeatability can be put into practical use.

Claims (8)

In an optical waveguide having a cladding layer and a core layer, the cladding layer is formed using an optical waveguide material mainly composed of a polyimide resin having a structural unit represented by the following general formulas (1) and (2). An optical waveguide having the characteristic flexibility.

However, Ar ₁ and Ar ₂ represents a tetravalent aromatic group represented by the formula (3) independently, a divalent aromatic group Ar ₃ is represented by the formula (4) or (5) R ₁ independently represents a monovalent hydrocarbon group having 1 to 8 carbon atoms, R ₃ independently represents a divalent hydrocarbon group having 2 to 6 carbon atoms, and R ₄ independently represents a carbon number 1 Represents a monovalent hydrocarbon group of ˜6, X and Y are independently a single bond or a divalent hydrocarbon group of 1 to 15 carbon atoms, a divalent hydrocarbon group selected from O, S, CO, SO ₂ or CONH. M represents a number of 1 to 50, n independently represents an integer of 0 to 4, p and q represent the molar ratio of each constituent unit, p is in the range of 0.05 to 0.99, q is in the range of 0.01 to 0.95.   The optical waveguide according to claim 1, wherein the core layer and the clad layer are formed using the optical waveguide material according to claim 1 having a refractive index different from each other.   The optical waveguide according to claim 2, wherein the refractive index difference Δ of the optical waveguide material forming the core layer and the clad layer is 0.01 or more.   The optical waveguide according to claim 1, wherein the optical waveguide has a core layer and a clad layer covering the periphery of the core layer, and the refractive index of the clad layer is lower than that of the core layer.   2. The optical waveguide according to claim 1, wherein the elastic modulus of the polyimide resin is in a range of 0.2 to 3.0 Gpa. A photosensitive resin composition having a core layer composed mainly of a polyamic acid resin having structural units represented by the following general formula (6) and general formula (7), a monomer having an unsaturated bond, and a photopolymerization initiator The optical waveguide according to claim 1, wherein the optical waveguide is formed using an optical waveguide material mainly composed of a resin obtained by curing.

(However, Ar ₁ , Ar ₂ , Ar ₃ , R ₃ and R ₄ have the same meaning as in the above general formulas (1) and (2), but R _{1 in} Ar ₃ or in general formula (7) (At least a part of R ₄ is an alkenyl group or an alkenylphenyl group)   A laminate for an optical-electric composite wiring board, wherein the optical waveguide according to claim 1 is formed on a flexible copper-clad laminate.   An optical-electric composite flexible wiring board, wherein the optical waveguide according to any one of claims 1 to 6 is formed on a flexible wiring board.

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