JP6022893B2 - Coverlay film, flexible printed wiring board using the same, and method for producing the same - Google Patents

Description

The present invention relates to a coverlay film. More specifically, the present invention relates to a coverlay film for a flexible printed wiring board.
The present invention also relates to a flexible printed wiring board using the coverlay film.
Moreover, this invention relates to the manufacturing method of this coverlay film and this flexible printed wiring board.

  2. Description of the Related Art In recent years, electronic devices with high performance, high functionality, and miniaturization are rapidly progressing, and there is an increasing demand for higher density, smaller size, and thinner electronic components used in electronic devices. As a result, further improvements in physical properties such as heat resistance, mechanical strength, and electrical characteristics have been required for electronic component materials. For example, printed circuit boards on which semiconductor elements are mounted are required to have higher density, higher functionality, and higher performance.

  Under such circumstances, there is an increasing demand for flexible printed wiring boards (hereinafter referred to as FPC) capable of three-dimensional wiring and mounting in a narrow space. In general, an FPC has a structure in which a circuit pattern is formed on a polyimide film having excellent heat resistance and flexibility, and a cover layer having an adhesive layer, that is, a so-called coverlay film is attached to the surface.

  The FPC cover lay film is required to have excellent adhesive strength with respect to FPC substrate materials such as metal foils and polyimide films that form the FPC wiring. For example, it is proposed in Patent Documents 1 to 3.

  In recent years, since the frequency of transmission signals in FPC has been remarkably increased, materials used for FPC are required to be able to reduce electrical signal loss in a high frequency region, specifically, in a frequency range of 1 to 10 GHz. The coverlay film is also required to exhibit excellent electrical characteristics (low dielectric constant (ε), low dielectric loss tangent (tan δ)) in a high frequency region.

  In the patent document 4, the applicant of the present application has excellent adhesive strength with respect to FPC substrate materials such as a metal foil forming an FPC wiring and a polyimide film, and has an electrical property in a high frequency range of 1 to 10 GHz. A coverlay film that exhibits characteristics, specifically, a low dielectric constant (ε) and a low dielectric loss tangent (tan δ) in a frequency range of 1 to 10 GHz is proposed. The cover lay film includes at least a vinyl compound having a specific structure (component (A)), a polystyrene-poly (ethylene / butylene) block copolymer, and a polystyrene-poly (ethylene-ethylene / propylene) block copolymer. One (component (B)), epoxy resin (component (C)), and curing catalyst (component (D)).

JP 2008-248141 A JP 2006-169446 A JP 2005-2448048 A JP 2011-68713 A

  At the time of manufacturing the FPC, the connecting portion of the FPC wiring is plated. However, by forming a fine hole in the coverlay film described in Patent Document 4, resistance of the FPC during the cleaning process after the plating process Specifically, it has become clear that there may be a problem in the resistance of the copper wiring of the FPC to the plating cleaning solution used in the cleaning step after the plating step.

The coverlay film is thermocompression-bonded after being placed at a predetermined position of the FPC, that is, a position covered with the coverlay film. The thermocompression bonding is performed by temporarily pressing the cover lay film onto the FPC and heat-curing the pressure while applying pressure. The thermo-compression causes the cover lay film to be heat-cured and bonded to the FPC.
The coverlay film described in Patent Document 4 has good circuit embeddability when bonded to an FPC, but due to the fluidity that causes the circuit embeddability, the coverlay film is subjected to a pressure-bonded surface during thermocompression of the coverlay film. If a fine convex part exists in the surface of (press surface), the fine concave part corresponding to this convex part will be formed in the coverlay film surface. The cause of the fine protrusions on the surface of the pressure-bonding surface (press surface) is mainly the fine protrusions present on the surface of the release film. This release film is sandwiched between the cushion material and the cover lay film at the time of thermocompression bonding of the cover lay film, and the fine convex portions are mainly applied to the surface of the release film. This is due to the release agent.

  The coverlay film is previously made small in size by the amount of the connecting portion formed at the end of the FPC wiring. At the time of thermocompression bonding of the coverlay film, the film is deformed and thinned at the end of the coverlay film. If fine convex portions exist at positions corresponding to the thinned portions of the cover lay film on the surface of the press surface, concave portions may be formed in the cover lay film and holes may be formed due to concentration of charges during the plating process. . If the plating cleaning solution enters through the holes during the cleaning step after the plating step, the copper wiring of the FPC is blackened (oxidized) or whitened (peeled), which leads to a decrease in circuit reliability.

  Moreover, the coverlay film described in Patent Document 4 may cause warpage called curl in the FPC due to shrinkage and strength of stress during thermosetting. When such curling occurs, the flexibility of the FPC that should be originally required is impaired, and for example, it becomes difficult to use as an FPC cable.

  In order to solve the above-described problems of the prior art, the present invention has excellent adhesive strength with respect to FPC substrate materials such as polyimide films, and electrical characteristics in a high frequency region of frequency 1 to 10 GHz, specifically Covers a low dielectric constant (ε) and a low dielectric loss tangent (tan δ) in the frequency range of 1 to 10 GHz, plating resistance, and curling during heat curing is suppressed. An object is to provide a ray film.

In order to achieve the above object, the present invention provides:
(A) a vinyl compound represented by the following general formula (1),
(In the formula, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ may be the same or different and each represents a hydrogen atom, a halogen atom, an alkyl group, a halogenated alkyl group or a phenyl group. -(O-X-O)-is represented by the following structural formula (2).

R ₈ , R ₉ , R ₁₀ , R ₁₄ , and R ₁₅ may be the same or different and are a halogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group. R ₁₁ , R ₁₂ and R ₁₃ may be the same or different and are a hydrogen atom, a halogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group. -(YO)-is a structure in which one type of structure defined by the following structural formula (3) or two or more types of structures defined by the following structural formula (3) are randomly arranged.

R ₁₆ and R ₁₇ may be the same or different and are a halogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group. R ₁₈ and R ₁₉ may be the same or different and are a hydrogen atom, a halogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group. Z is an organic group having 1 or more carbon atoms, and may contain an oxygen atom, a nitrogen atom, a sulfur atom, or a halogen atom. a and b each represents an integer of 0 to 300, at least one of which is not 0. c and d represent an integer of 0 or 1. )
(B) polystyrene-poly (ethylene / butylene) block copolymer,
(C) polystyrene-poly (ethylene-ethylene / propylene) block copolymer,
(D) epoxy resin,
(E) Bismaleimide is included, and the mass ratio of each component is (A + E) / (B + C) = 0.81 or more and 1.00 or less, and (B) / (C) = 1.00 or more and 4.00 or less. And the adhesive layer which contains the said component (D) 1-10 mass% with respect to the total mass of the said components (A)-(E),
One surface of an organic film having a melting point higher than the thermosetting temperature of the adhesive layer, having a dielectric constant (ε) of 4.0 or less and a dielectric loss tangent (tan δ) of 0.02 or less in a frequency range of 1 to 10 GHz. A cover lay film is provided.

In the coverlay film of the present invention,-(O-X-O)-of the component (A) is represented by the following structural formula (4), and-(YO)-of the component (A) is Structural formula (5), or a structure represented by the following structural formula (6), or a structure represented by the following structural formula (5) and a structure represented by the following structural formula (6) are randomly arranged. It is preferable.

  In the coverlay film of the present invention, it is preferable that — (YO) — of the component (A) has a structure represented by the structural formula (6).

  In the coverlay film of the present invention, it is preferable that the lowest melt viscosity of the adhesive layer in a temperature range of 150 to 200 ° C. is 2000 Pa · s or more and 10,000 Pa · s or less.

  The cover lay film of the present invention has a dielectric constant (ε) of 3.5 or less and a dielectric loss tangent (tan δ) of 0.02 or less in a frequency range of 1 to 10 GHz after the adhesive layer is thermally cured. It is preferable.

  The cover lay film of the present invention has a dielectric constant (ε) of 2.5 or less and a dielectric loss tangent (tan δ) of 0 or less in a frequency range of 1 to 10 GHz after the adhesive layer is thermally cured. It is preferable that it is 004 or less.

  In the coverlay film of the present invention, it is preferable that the organic film is produced using any one of liquid crystal polymer, polyimide, polyethylene naphthalate, and polytetrafluoroethylene.

  In addition, the present invention provides a cover of the present invention on the wiring pattern side of a resin substrate with wiring in which a wiring pattern is formed on the main surface of a resin substrate mainly composed of liquid crystal polymer, polyimide, or polyethylene naphthalate. Provided is a flexible printed wiring board in which a lay film is disposed so that adhesive layers face each other, and the resin substrate with wiring and the cover lay film are integrated by thermocompression bonding.

  In addition, the present invention provides a resin substrate with wiring in which a wiring pattern is formed on a main surface of a resin substrate mainly composed of the vinyl compound represented by the general formula (1) and rubber and / or thermoplastic elastomer. The cover lay film of the present invention is disposed on the wiring pattern side so that the adhesive layers face each other, and the resin substrate with wiring and the cover lay film are integrated by thermocompression bonding. A flexible printed wiring board is provided.

Further, the present invention is a method for producing a coverlay film in which an adhesive layer is formed on one side of an organic film,
(A) a vinyl compound represented by the above general formula (1),
(B) polystyrene-poly (ethylene / butylene) block copolymer,
(C) polystyrene-poly (ethylene-ethylene / propylene) block copolymer,
(D) epoxy resin,
(E) Bismaleimide is included, and the mass ratio of each component is (A + E) / (B + C) = 0.81 or more and 1.00 or less, and (B) / (C) = 1.00 or more and 4.00 or less. And the varnish which consists of a resin composition which contains the said component (D) 1-10 mass% with respect to the total mass of the said components (A)-(E),
An organic film having a melting point higher than the thermosetting temperature of the resin composition, a dielectric constant (ε) of 4.0 or less, and a dielectric loss tangent (tan δ) of 0.02 or less in a frequency range of 1 to 10 GHz. Provided is a method for producing a coverlay film, wherein the adhesive layer is formed by applying to one side and drying.

Further, the present invention is a method for producing a coverlay film in which an adhesive layer is formed on one side of an organic film,
(A) a vinyl compound represented by the above general formula (1),
(B) polystyrene-poly (ethylene / butylene) block copolymer,
(C) polystyrene-poly (ethylene-ethylene / propylene) block copolymer,
(D) epoxy resin,
(E) Bismaleimide is included, and the mass ratio of each component is (A + E) / (B + C) = 0.81 or more and 1.00 or less, and (B) / (C) = 1.00 or more and 4.00 or less. And an adhesive film is produced from the resin composition containing 1 to 10% by mass of the component (D) with respect to the total mass of the components (A) to (E), and the adhesive film, An organic film having a melting point higher than the thermosetting temperature of the adhesive film, a dielectric constant (ε) of 4.0 or less, and a dielectric loss tangent (tan δ) of 0.02 or less in a frequency range of 1 to 10 GHz. Provided is a method for manufacturing a coverlay film, wherein the adhesive layer is formed by bonding.

In addition, the present invention provides a resin substrate with wiring by providing a wiring pattern on the main surface of a resin substrate mainly composed of any of liquid crystal polymer, polyimide, and polyethylene naphthalate,
The cover lay film of the present invention is arranged on the wiring pattern side of the resin substrate with wiring so that the adhesive layer is opposed to the resin substrate, and the resin substrate with wiring and the cover lay film are integrated by thermocompression bonding. A method of manufacturing a flexible printed wiring board is provided.

Further, the present invention provides a wiring pattern on the main surface of a resin substrate mainly composed of the vinyl compound (a) represented by the general formula (1) and rubber and / or thermoplastic elastomer (b). Make a resin board with wiring,
The cover lay film of the present invention is arranged on the wiring pattern side of the resin substrate with wiring so that the adhesive layer is opposed to the resin substrate, and the resin substrate with wiring and the cover lay film are integrated by thermocompression bonding. A method of manufacturing a flexible printed wiring board is provided.

The cover lay film of the present invention has excellent adhesive strength with respect to FPC substrate materials such as metal foil and polyimide film forming the wiring of FPC, and excellent electrical characteristics in the high frequency region, specifically Since it has a low dielectric constant (ε) and a low dielectric loss tangent (tan δ) in a frequency range of 1 to 10 GHz, it is suitable as a coverlay film for FPC.
In addition, the coverlay film of the present invention has an appropriate amount of bleeding when adhering to the substrate, so that the workability when adhering the coverlay film is excellent, and the embedding property of the circuit is impaired. There is no.
In addition, since the cover lay film of the present invention is provided with plating resistance, infiltration of the plating cleaning solution during the cleaning process after the plating process of the FPC wiring connect portion and the black wiring of the FPC copper wiring thereby. (Oxidation) and whitening (peeling) are prevented, and the reliability of the circuit is improved.
Further, the cover lay film of the present invention suppresses the occurrence of curling during thermosetting, and does not impair the flexibility of the FPC.

Hereinafter, the coverlay film of the present invention will be described in detail.
The coverlay film of the present invention is a coverlay film having a two-layer structure in which an adhesive layer is formed on one side of an organic film.

[Organic film]
The organic film in the coverlay film of the present invention has a function as a protective coating that imparts plating resistance to the coverlay film.
As described above, the coverlay film preferably has high fluidity during thermocompression bonding with the FPC in order to achieve good circuit embedding when bonded to the FPC.
However, at the time of thermocompression bonding with the FPC, if the fluidity of the coverlay film is high, thinning occurs at the edge of the coverlay film, and at the position corresponding to the thinned portion of the coverlay film on the surface of the press surface, When there are fine convex portions, concave portions are formed in the coverlay film, and holes may be formed due to concentration of electric charges during the plating process. If the plating cleaning solution enters through the holes during the cleaning step after the plating step, the copper wiring of the FPC is blackened (oxidized) or whitened (peeled), which leads to a decrease in circuit reliability.
The cover lay film of the present invention achieves the embedding property of a circuit when bonded to an FPC with an adhesive layer having high fluidity at the time of thermocompression bonding with the FPC, while the adhesive layer is formed on one side. To give plating resistance.
For this reason, the organic film in this invention is calculated | required not to form the recessed part which leads to a plating process defect in an contact bonding layer at the time of thermocompression bonding with FPC.
In order to achieve this, an organic film having a melting point higher than the thermosetting temperature of the adhesive layer is used as the organic film in the present invention. As the resin having no melting point, for example, a resin having a glass transition temperature higher than the curing temperature of the adhesive layer is used. If the organic film has a melting point higher than the thermosetting temperature of the adhesive layer, there will be no formation of recesses in the adhesive layer during thermocompression bonding with the FPC, preventing the formation of holes in the coverlay film. Is done. As a result, the plating resistance at the time of a plating process is provided.
In addition, although mentioned later in detail, the thermosetting temperature of a contact bonding layer is 180-210 degreeC.

The required characteristics for the coverlay film of the present invention include a low dielectric constant (ε) and a low dielectric loss tangent (tan δ) in a frequency range of 1 to 10 GHz. Specifically, after bonding with the FPC, that is, after the thermosetting of the adhesive layer, the dielectric constant (ε) is 3.5 or less and the dielectric loss tangent (tan δ) is 0.02 in the frequency region of 1 to 10 GHz. The following is required.
For this reason, the organic film is also required to have a low dielectric constant (ε) and a low dielectric loss tangent (tan δ) in a frequency range of 1 to 10 GHz. Specifically, in the frequency range of 1 to 10 GHz, the dielectric constant (ε) is required to be 4.0 or less, and the dielectric loss tangent (tan δ) is required to be 0.02 or less.
In addition, about the contact bonding layer, in the area | region of frequency 1-10GHz, the dielectric constant ((epsilon)) after thermosetting of this contact bonding layer is 2.5 or less, and a dielectric loss tangent (tan-delta) is 0.004 or less. Desired.

The organic film in the present invention is selected from the above-mentioned conditions regarding the melting point and the conditions regarding the dielectric constant and the dielectric loss tangent.
Specific examples of the organic film satisfying these include organic films prepared using liquid crystal polymer (LCP) or polytetrafluoroethylene (PTFE). Since LCP and PTFE are excellent in electrical characteristics in a high frequency range of frequency 1 to 10 GHz, an organic film produced using LCP and PTFE has a dielectric constant (ε) of 3 in a frequency range of 1 to 10 GHz. 0 or less and the dielectric loss tangent (tan δ) is 0.0030 or less.
Moreover, as another specific example of the organic film satisfying these, the dielectric constant (ε) in the region of the frequency of 1 to 10 GHz made using polyimide (PI) or polyethylene naphthalate (PEN) is 4.0 or less. And an organic film having a dielectric loss tangent (tan δ) of 0.02 or less.
For organic films produced using these PI and PEN, the dielectric constant (ε) in the frequency region of 1 to 10 GHz is 4.0 or less and the dielectric loss tangent (tan δ) is 0 by appropriately selecting the film grade. 0.02 or less. In addition, depending on the grade of PI or PEN and the thickness of the film, the dielectric constant in the frequency range of 1 to 10 GHz can be 3.0 or less and the dielectric loss tangent can be 0.006 or less.
Therefore, the thickness of the film is selected according to the material of the organic film to be used. Here, LCP and PTFE are excellent in electrical characteristics in the high frequency region as described above, and thus the thickness is not particularly limited. However, the thickness is preferably 1 to 100 μm from the viewpoint of reducing the thickness of the coverlay film. 1 to 50 μm is more preferable, and 1 to 30 μm is even more preferable.
In the case of an organic film prepared using PI or PEN, the thickness is preferably 0.5 to 100 μm, more preferably 0.5 to 50 μm, although depending on the grade. More preferably, it is ˜30 μm.

In the case of a film produced using LCP, an LCP film such as “BEXTER (registered trademark)” manufactured by Kuraray Co., Ltd., “BIAC” manufactured by Nippon Gore Co., Ltd., or the like can be used. In addition, “Vectra (registered trademark)” manufactured by Polyplastics Co., Ltd., “Syberas (registered trademark)” manufactured by Toray Industries, Inc., “Sumika Super (Sumika Super) LCP” manufactured by Sumitomo Chemical Co., Ltd., etc. The LCP material may be formed into a film having a desired thickness.
In the case of films made using PI, “Kapton (registered trademark)” manufactured by Toray DuPont, “Zenomax (registered trademark)” manufactured by Toyobo Co., Ltd., “UPILEX (registered trademark) manufactured by Ube Industries, Ltd. (Trademark) S "and" Apical (registered trademark) "manufactured by Kaneka Corporation can be used. Alternatively, a PI material such as “Aurum (registered trademark)” manufactured by Mitsui Chemicals, Inc. may be used in a desired thickness.
In the case of a film produced using PEN, “Teonex (registered trademark)” manufactured by Teijin DuPont Films may be used.
In the case of a film produced using PTFE, “Nitoflon (registered trademark)” manufactured by Nitto Denko Corporation, “Naflon (registered trademark)” manufactured by Nichias Corporation, “Vulflon (registered trademark)” manufactured by Nippon Valqua Industries, Ltd. ) "Can be used.

[Adhesive layer]
As described above, the cover lay film of the present invention is required to have high fluidity of the adhesive layer at the time of thermocompression bonding with the FPC in order to improve the circuit embedding property when adhering to the FPC. As will be described later, the temperature of the coverlay film of the present invention during temporary pressure bonding is 100 to 150 ° C., and the temperature during heat curing is 150 to 210 ° C. In the coverlay film of the present invention, it is preferable that the lowest melt viscosity of the adhesive layer in the temperature range of 150 to 210 ° C. is 2000 Pa · s or more and 10,000 Pa · s or less. Here, the minimum melt viscosity is a minimum value of the viscosity when the adhesive layer is melted when the adhesive layer is heated.

The required characteristics for the coverlay film of the present invention include a low dielectric constant (ε) and a low dielectric loss tangent (tan δ) in a frequency range of 1 to 10 GHz. Specifically, after adhesion with FPC, that is, after heat-curing of the adhesive layer, the dielectric constant (ε) is 3.5 or less and the dielectric loss tangent (tan δ) is 0.02 in the frequency region of 1 to 10 GHz. The following is required.
For this reason, the adhesive layer in the present invention has a cured product having a dielectric constant (ε) of 2.5 or less and a dielectric loss tangent (tan δ) of 0.004 or less in a frequency range of 1 to 10 GHz. Desired.

  In order to satisfy the above-mentioned conditions regarding the minimum melt viscosity and the conditions regarding the dielectric constant and the dielectric loss tangent, the adhesive layer in the present invention includes the following components (A) to (E) as essential components.

(A) a vinyl compound represented by the following general formula (1),

In the general formula (1), R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ and R ₇ may be the same or different, and are a hydrogen atom, a halogen atom, an alkyl group, a halogenated alkyl group or It is a phenyl group. Among _{these, R 1, R 2, R} 3, R 4, R 5, is preferably R _6, R ₇ is a hydrogen atom.
In the formula, — (O—X—O) — is represented by the following structural formula (2).

In the structural formula (2), R ₈ , R ₉ , R ₁₀ , R ₁₄ , and R ₁₅ may be the same or different, and are a halogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group. Among these, R ₈ , R ₉ , R ₁₀ , R ₁₄ , and R ₁₅ are preferably alkyl groups having 6 or less carbon atoms. Among these, R ₁₁ , R ₁₂ and R ₁₃ are preferably a hydrogen atom, a halogen atom or an alkyl group having 6 or less carbon atoms.
In the general formula (1),-(YO)-is a random arrangement of one type of structure defined by the following structural formula (3) or two or more types of structures defined by the following structural formula (3). It is a thing.

In the structural formula (3), R ₁₆ and R ₁₇ may be the same or different, and are a halogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group. Among these, R ₁₆ and R ₁₇ are preferably alkyl groups having 6 or less carbon atoms.
R ₁₈ and R ₁₉ may be the same or different and are a hydrogen atom, a halogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group. Among these, R ₁₈ and R ₁₉ are preferably a hydrogen atom or an alkyl group having 3 or less carbon atoms.
In general formula (1), Z is an organic group having 1 or more carbon atoms and may contain an oxygen atom, a nitrogen atom, a sulfur atom, or a halogen atom. Among these, it is preferable that Z is a methylene group.
a and b each represents an integer of 0 to 300, at least one of which is not 0.
c and d represent an integer of 0 or 1. Among these, c and d are preferably 1.
Among these, R ₈ , R ₉ , R ₁₀ , R ₁₄ and R ₁₅ are preferably an alkyl group having 3 or less carbon atoms, R ₁₁ , R ₁₂ and R ₁₃ are a hydrogen atom or an alkyl group having 3 or less carbon atoms, R ₁₆ and R ₁₇ are alkyl groups having 3 or less carbon atoms, and R ₁₈ and R ₁₉ are hydrogen atoms.

In addition, — (O—X—O) — in the general formula (1) is preferably represented by the following structural formula (4).

In addition, in the general formula (1),-(YO)-is a structure represented by the following structural formula (5) or the following structural formula (6), or a structure represented by the following structural formula (5) and It is preferable to have a structure in which the structure represented by the following structural formula (6) is randomly arranged. Among these,-(YO)-preferably has a structure in which structures defined by the following structural formula (6) are arranged.

In the cover lay film of the present invention, the component (A) is thermosetting, heat resistant, and excellent electrical properties at high frequencies, that is, a low dielectric constant (ε) in a frequency range of 1 to 10 GHz, It also contributes to the low dielectric loss tangent (tan δ).
Moreover, a component (A) acts as a compatibilizer of the component (B), the component (C), the component (D), and the component (E) described later.

The method for producing the vinyl compound represented by the general formula (1) is not particularly limited, and may be produced by any method. For example, with respect to the compound represented by the following general formula (7), chloromethylstyrene in the presence of an alkali catalyst such as sodium hydroxide, potassium carbonate, sodium ethoxide and the like, benzyltri n-butylammonium bromide, 18- It can obtain by making it react using phase transfer catalysts, such as crown-6-ether.

-(OXO) and-(YO)-in the general formula (7) are as described above for the general formula (1).

Component (B) Polystyrene-poly (ethylene / butylene) block copolymer Component (C): Polystyrene-poly (ethylene-ethylene / propylene) block copolymer In the coverlay film of the present invention, the components (B), (C ) Contributes to excellent electrical properties of the adhesive layer at high frequencies (low dielectric constant (ε) and low dielectric loss tangent (tan δ) in a frequency range of 1 to 10 GHz) and heat resistance.
Among these, the component (B) has high heat resistance because of high crystallinity of the poly (ethylene / butylene) portion, and imparts heat resistance to the adhesive layer. On the other hand, the component (C) has a lower crystallinity of the poly (ethylene-ethylene / propylene) portion than the corresponding portion (poly (ethylene / butylene) portion) of the component (B), so Adhesive strength to the substrate is high.
For this reason, in this invention, a component (B) and (C) are used in the contact bonding layer with the specific mixture ratio described below.

In the present invention, the mass ratio of the components (B) and (C) in the adhesive layer is (B) / (C) = 1.00 or more and 4.00 or less.
When (B) / (C) is less than 1.00, desired adhesive strength can be obtained, but the adhesive layer becomes highly elastic, and the stress at the time of curing is strong, so that curling is likely to occur.
On the other hand, if (B) / (C) = 4.00, the adhesive layer can be made of low elasticity and curling can be suppressed, but the desired adhesive strength cannot be obtained.
The mass ratio of the components (B) and (C) is more preferably (B) / (C) = 1.5 or more and 3.5 or less.

Component (D): Epoxy resin In the coverlay film of the present invention, the component (D) contributes to the thermosetting property and adhesiveness of the adhesive layer of the coverlay film.
The adhesive layer of the coverlay film of this invention contains 1-10 mass% of components (D) with respect to the total mass of components (A)-(E).
When the said component (D) is less than 1 mass%, there exists a problem that the adhesiveness of a coverlay film becomes inadequate.
When the component (D) exceeds 10% by mass, the compatibility is deteriorated and a desired dielectric loss tangent (tan δ) value cannot be obtained. In addition, the amount of oozing out when the coverlay film is bonded becomes excessively large. Furthermore, since the ratio of the component (D) which occupies in all the components increases, the characteristic of the component (D) which is inferior in heat resistance affects the whole adhesive layer of a coverlay film. Therefore, there exists a possibility that the heat resistance and sclerosis | hardenability of the adhesive layer of a coverlay film may fall.
The coverlay film of the present invention more preferably contains 1 to 5% by mass of the component (D) with respect to the total mass of the components (A) to (E).

The epoxy resin used as the component (D) is not particularly limited, and various epoxy resins such as a novolac type epoxy resin, a bisphenol A type epoxy resin, a bisphenol F type epoxy resin and a biphenyl type epoxy resin can be used.
As a specific example of the novolac type epoxy resin, JER 152 (manufactured by Japan Epoxy Resin Co., Ltd.) may be mentioned.
Specific examples of the bisphenol A type epoxy resin include JER 828 (manufactured by Japan Epoxy Resin Co., Ltd.).
Specific examples of the bisphenol F type epoxy resin include JER 806 (manufactured by Japan Epoxy Resin Co., Ltd.).
Specific examples of the biphenyl type epoxy resin include JER FX4000 (manufactured by Japan Epoxy Resin Co., Ltd.) and NC3000H (manufactured by Nippon Kayaku Co., Ltd.).
In addition, among said epoxy resins, any 1 type may be used and 2 or more types may be used together.
Among the above epoxy resins, bisphenol A type epoxy resins and biphenyl type epoxy resins are preferable, and biphenyl type epoxy resins are more preferable from the viewpoint of excellent adhesive strength.

  The epoxy resin used as the component (D) preferably has a number average molecular weight (Mn) of 150 to 2500 for reasons of thermosetting, adhesiveness, and mechanical properties after curing.

Component (E): Bismaleimide In the coverlay film of the present invention, the bismaleimide of the component (E) acts with the vinyl compound of the component (A) to cause heat curing of the adhesive layer of the coverlay film at a lower temperature (for example, In general, those cured at 200 ° C. can be cured at 150 ° C.).
In the present invention, bismaleimide is used because it is preferable from the viewpoints of maintaining dielectric properties, imparting adhesive strength, and increasing Tg (glass transition point).

  The blending amount of the component (E) bismaleimide is preferably determined by the equivalent ratio of the vinyl compound of the component (A) to the vinyl group. Specifically, the bismaleimide of the component (E) is 0.1 to 3 equivalents and 0.5 to 1.5 equivalents with respect to 1 equivalent of the vinyl group of the vinyl compound of the component (A). Preferably, it is 0.8-1.3 equivalent.

In the coverlay film of the present invention, components (A) and (E) are thermosetting resin materials, and components (B) and (C) are thermoplastic resin materials.
In the coverlay film of the present invention, the blending ratio of these thermosetting resin material and thermoplastic resin material affects the physical properties of the adhesive layer of the coverlay film. Therefore, (components (A), (E)) and (components (B), (C)) are used in the specific blending ratio described below.
In addition, although the epoxy resin of a component (D) is also a thermosetting resin material, as above-mentioned, content of a component (D) is 1 with respect to the total mass of a component (A)-(E). Since it is as low as -10% by mass, the component (D) can be obtained by using (components (A), (E)) and (components (B), (C)) and the specific blending ratio described below. The influence on the physical properties of the adhesive layer of the coverlay film is negligible.

In the coverlay film of the present invention, the mass ratio between the total amount of components (A) and (E) and the total amount of components (B) and (C) is (A + E) / (B + C) = 0.81. More than 1.00.
If the mass ratio of each component is less than (A + E) / (B + C) = 0.81, desired adhesive strength cannot be obtained.
On the other hand, when it exceeds (A + E) / (B + C) = 1.00, it becomes highly elastic, and it becomes easy to generate curl because the stress at the time of curing is strong.

The adhesive layer of the coverlay film of the present invention may contain a curing catalyst as the component (F) in addition to the components (A) to (E). This curing catalyst acts as a curing catalyst for the epoxy resin of component (D).
As a component (F), when a curing catalyst is contained, it is preferable to contain 0.001-5 mass% with respect to the total mass of a component (A)-(F).
When the content of the component (F) is less than 0.001% by mass, the adhesive layer of the cover lay film cannot be cured in a short time, so that there are problems such as insufficient adhesion.
On the other hand, when the content of the component (F) exceeds 5% by mass, there is a problem that the curing catalyst is precipitated after the formation of the adhesive layer.
As a component (F), when a curing catalyst is contained, it is more preferable to contain 0.01-3 mass% with respect to the total mass of a component (A)-(F).

  If the curing catalyst used as a component (F) is a curing catalyst of an epoxy resin, it will not specifically limit, A well-known thing can be used. For example, an imidazole-based curing catalyst, an amine-based curing catalyst, a phosphorus-based curing catalyst, and the like can be given.

Examples of imidazole-based curing catalysts include 2-methylimidazole, 2-undecylimidazole, 1-cyanoethyl-2-undecylimidazole, 2-heptadecylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-ethyl. Examples include imidazole compounds such as -4-imidazole, 2-phenylimidazole, and 2-phenyl-4-methylimidazole. Of these, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-undecylimidazole, and 1-cyanoethyl-2-ethyl-4-imidazole are preferable.
Examples of amine-based curing catalysts include triazine compounds such as 2,4-diamino-6- [2′-methylimidazolyl- (1 ′)] ethyl-s-triazine, 1,8-diazabicyclo [5,4,0] undecene. And tertiary amine compounds such as -7 (DBU), triethylenediamine, benzyldimethylamine, and triethanolamine. Among these, 2,4-diamino-6- [2′-methylimidazolyl- (1 ′)] ethyl-s-triazine is preferable.
Examples of the phosphorus curing catalyst include triphenylphosphine, tributylphosphine, tri (p-methylphenyl) phosphine, and tri (nonylphenyl) phosphine.

  Among these, an imidazole-based curing catalyst is particularly preferable because it promotes low-temperature curing only with an organic component.

The adhesive layer of the cover lay film of the present invention may further contain other components as necessary. Specific examples of such components include flame retardants, modifiers, and fillers.
Moreover, in order to improve the adhesiveness to a board | substrate, it is a silicone alkoxy oligomer, You may contain the silane coupling agent which has a hydroxyl group, an epoxy, vinyl, methyl, amino, isocyanate etc. as a functional group.

(Flame retardants)
As the flame retardant, a known flame retardant such as phosphate ester, for example, trimethyl phosphate, triphenyl phosphate, tricresyl phosphate can be used.
When a flame retardant is contained, it is preferable to contain 1 to 200 parts by mass of the flame retardant with respect to the total mass of the components (A) to (F) and the flame retardant, and 5 to 100% by mass. More preferably, it is more preferable to make it contain 10-50 mass%.

Next, the preparation procedure of the coverlay film of the present invention, that is, the procedure for forming an adhesive layer on one side of the organic film is shown.
For example, in the presence or absence of a solvent, the components (A) to (E) of the above-mentioned adhesive layer (in the case of containing the component (F) and in the case of containing other optional components, these optional items) Components) are mixed by a heating vacuum mixing kneader to obtain a resin composition containing these components.
Specifically, such a component (A) to component (E) have a desired content ratio (when the above component (F) and other optional components are contained, these optional components are further desired). Dissolved in a predetermined solvent concentration, put them into a reaction kettle heated to 10 to 80 ° C., and mixed at atmospheric pressure while rotating at a rotational speed of 100 to 1000 rpm. Do time.
A cover lay film in which an adhesive layer is formed on one side of the organic film can be produced by applying the varnish containing the resin composition thus obtained to one side of the organic film and drying it.

  Examples of the solvent that can be used as the varnish include ketones such as methyl ethyl ketone and methyl isobutyl ketone; aromatic solvents such as toluene and xylene; high-boiling solvents such as dioctyl phthalate and dibutyl phthalate. Although the usage-amount of a solvent is not specifically limited, Although it can be set as the quantity conventionally used, Preferably, it is 20-90 mass% with respect to solid content.

  The method for applying the varnish is not particularly limited, and examples thereof include a slot die method, a micro gravure method, a doctor coater method, and the like, which are appropriately selected according to a desired adhesive layer thickness, etc. The die method is preferable because the thickness of the adhesive layer can be designed thin. Application | coating is performed so that the thickness of the contact bonding layer formed after drying may become desired thickness. Such a thickness can be derived from the solvent content by those skilled in the art.

  The drying conditions are appropriately designed according to the type and amount of the solvent used in the varnish, the amount of varnish used, the thickness of the coating, etc., and are not particularly limited, for example, 60 to 120 ° C., It can be performed under atmospheric pressure.

  The thickness of the adhesive layer formed after drying is generally 1 to 100 μm, and when thinning is required, it is preferably 1 to 30 μm. Actually, the thickness of the adhesive layer is selected according to the wiring height on the FPC to which the coverlay film is attached.

  Moreover, after apply | coating the varnish obtained by said procedure to the at least single side | surface of a support body and making it dry, the adhesive film and organic film which peeled from the support body were temporarily pressure-bonded at 100-150 degreeC. A cover lay film in which an adhesive layer is formed on one side of an organic film can also be produced by bonding them together.

  The support is not particularly limited, and examples thereof include metal foils such as copper and aluminum, and carrier films of resins such as polyester and polyethylene. The support is preferably subjected to a release treatment with a silicone compound or the like.

  The coverlay film of the present invention has characteristics suitable as a coverlay film for FPC as shown below.

The cover lay film of the present invention is excellent in high frequency electrical characteristics after heat curing. Specifically, the coverlay film after heat curing preferably has a dielectric constant (ε) in the region of frequency 1 to 10 GHz of 3.5 or less, and more preferably 3.0 or less.
The dielectric loss tangent (tan δ) in the frequency region of 1 to 10 GHz is preferably 0.02 or less, more preferably 0.01 or less, and further preferably 0.0075 or less.
When the dielectric constant (ε) and the dielectric loss tangent (tan δ) in the frequency range of 1 to 10 GHz are in the above ranges, the electric signal loss in the frequency range of 1 to 10 GHz can be reduced.
In order to achieve these, the adhesive layer of the cover lay film of the present invention is such that the cured product has a dielectric constant (ε) of 2.5 or less and a dielectric loss tangent (tan δ) of 0 in a frequency range of 1 to 10 GHz. .004 or less is required.
In addition, the dielectric constant (ε) and the dielectric loss tangent (tan δ) of the adhesive film shown in the examples described later correspond to the dielectric constant (ε) and the dielectric loss tangent (tan δ) of the cured product of the adhesive layer.

  The coverlay film of the present invention preferably has a tensile elastic modulus of 250 to 400 MPa after heat-curing of the adhesive layer from the viewpoint of stress relaxation due to low elasticity.

  The cover lay film of the present invention preferably has a glass transition temperature of 190 to 250 ° C. from the viewpoint of heat resistance and long-term reliability.

  In the cover lay film of the present invention, it is preferable that the curl of the adhesive layer measured by the procedure described in Examples described later is D <15 mm or less.

Next, the procedure for using the coverlay film of the present invention will be shown.
The cover lay film of the present invention is placed at a predetermined position on the resin substrate with wiring on which the wiring pattern is formed on the main surface, that is, on the side where the wiring pattern is formed, with the cover lay film. After being arranged so that the adhesive layers face each other, they may be thermocompression bonded at a predetermined temperature and for a predetermined time.
The temperature at the time of temporary pressure bonding among thermocompression bonding is preferably 100 to 150 ° C. The pre-bonding time is preferably 0.5 to 10 minutes.
The temperature of heat curing is preferably 150 to 210 ° C. The heat curing time is preferably 30 to 120 minutes.

The flexible printed wiring board (FPC) of the present invention has the coverlay film of the present invention disposed on the wiring pattern side of the resin substrate with wiring having a wiring pattern formed on the main surface so that the adhesive layer faces, By crimping, the resin substrate with wiring and the coverlay film are integrated.
The resin substrate used for the FPC of the present invention also has excellent electrical characteristics in a high frequency region, that is, a low dielectric constant (ε) and a low dielectric loss tangent (tan δ) in a frequency region of 1 to 10 GHz. It is preferable. As a specific example of such a resin substrate, a resin substrate whose main component is one of liquid crystal polymer (LCP), polytetrafluoroethylene (PTFE), polyimide (PI), and polyethylene naphthalate (PEN). Is mentioned.

As another specific example of the resin substrate suitable for the FPC of the present invention,
(A) a vinyl compound represented by the following general formula (1), and
(B) rubber and / or thermoplastic elastomer,
And a resin substrate containing as a main component.
About the vinyl compound represented by the said Formula (1) of a component (a), it is as having mentioned above about the adhesive layer of the coverlay film of this invention.
(A) The vinyl compound represented by the general formula (1) and (b) a resin substrate mainly composed of rubber and / or thermoplastic elastomer have the same configuration as the coverlay film of the present invention. It has a low dielectric constant and low dielectric loss tangent. For this reason, it can be set as FPC excellent in the high frequency characteristic by combining with the coverlay film of this invention.

Component (b): rubber and / or thermoplastic elastomer,
The specific example of the resin substrate suitable for the FPC of the present invention described above contains at least one of rubber and thermoplastic elastomer as the component (b). The resin substrate may contain both rubber and a thermoplastic elastomer.

Examples of the component (b) rubber include rubbers such as styrene-butadiene rubber, butyl rubber, butadiene rubber, and acrylic rubber. These rubbers may be used alone or in combination of two or more.
On the other hand, examples of the thermoplastic elastomer include a styrene thermoplastic elastomer, an olefin thermoplastic elastomer, and a polyester thermoplastic elastomer. A thermoplastic elastomer may be used individually by 1 type, and may use 2 or more types together.

As the component (b), a thermoplastic elastomer is preferable (for reasons such as the resin substrate being excellent in flexibility, and a styrene-based thermoplastic elastomer is particularly preferable.
Specific examples of the styrene-based thermoplastic elastomer include a styrene-butadiene block copolymer, a styrene-isoprene-styrene block copolymer, or a copolymer obtained by hydrogenating a part of their double bonds. More specifically, styrene-butadiene-styrene block copolymer (SBS), styrene-isoprene-styrene block copolymer (SIS), styrene-ethylene-butylene-styrene block copolymer (SEBS), styrene-ethylene. -Propylene-styrene block copolymer (SEEPS) etc. are mentioned. Among these, SBS and SEBS are preferable.

When using a styrene-type thermoplastic elastomer as a component (b), it is preferable that a mass mean molecular weight is 20,000-250,000. Moreover, since compatibility with a component (a) is favorable and a resin substrate is excellent in transparency, it is preferable that styrene content in a styrene-type thermoplastic elastomer is 25-60 mass%, More preferably, 30- 50% by mass. The mass average molecular weight is a value determined by GPC using a standard polystyrene calibration curve.
Specific examples of the styrene thermoplastic elastomer include a styrene-butadiene block copolymer “JSR TR” series and a styrene-isoprene block copolymer “JSR SIS” series manufactured by JSR Corporation.

Specific examples of the resin substrate suitable for the FPC of the present invention described above include two or more isocyanate groups or blocked in one molecule as the component (c) in addition to the components (a) and (b) described above. It is preferable to contain a urethane prepolymer having an isocyanate group. Such a urethane prepolymer includes a polyol and a compound having two or more isocyanate groups or blocked isocyanate groups in at least one molecule.
The urethane prepolymer of component (c) contributes to the adhesiveness of the resin substrate, and improves the adhesiveness of the resin substrate in the temperature range when the wiring pattern is transferred to the resin substrate.

Specific examples of the polyol used as a raw material for the urethane prepolymer of component (c) are a polyolefin-based polyol obtained by hydrogenating polybutadiene polyol, polyisoprene polyol, polyisoprene polyol, etc., and dimer acid using dimer acid as a carboxylic acid component. A polyester polyol etc. are mentioned.
Moreover, as another specific example of the polyol used as a raw material of the urethane prepolymer of component (c), bifunctional alcohols such as 1,4-butanediol, 1,6-hexanediol, and ethylene glycol, trimethylolpropane, etc. A trifunctional alcohol is mentioned.
Two or more of these polyols may be used in combination.

  The compound having an isocyanate group used as a raw material for the urethane prepolymer of component (c) is not particularly limited as long as it has two or more isocyanate groups or blocked isocyanate groups in total in one molecule. Specific examples of the compound having two or more isocyanate groups in one molecule include tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, and the like. However, tolylene diisocyanate and isophorone diisocyanate are particularly suitable. Moreover, as a compound which has the blocked isocyanate group, the compound which blocked the compound which has the isocyanate group illustrated here with blocking agents, such as alcohol, phenols, and oximes, is mentioned.

  Preferred urethane prepolymer as component (c) is a urethane prepolymer containing 50 parts by mass or more of a urethane prepolymer obtained from polybutadiene polyol and 1,4-butanediol and tolylene diisocyanate, isophorone diisocyanate or hexamethylene diisocyanate. It is.

  The specific example of the resin substrate suitable for the FPC of the present invention described above preferably contains a silane coupling agent as the component (d) in addition to the components (a) to (c). The component (d) silane coupling agent contributes to adhesion between the resin substrate and the wiring pattern when the wiring pattern is transferred to the resin substrate.

  Specific examples of the silane coupling agent used as component (d) include vinyl silane silane coupling agents, (meth) acryloxy silane silane coupling agents, isocyanate silane silane coupling agents, and epoxy silane silane coupling agents. , Aminosilane-based silane coupling agents, mercaptosilane-based silane coupling agents, chloropropylsilane-based silane coupling agents, and oligomers of these silane coupling agents. Among these, (meth) acryloxysilane-based silane coupling agents and aminosilane-based silane coupling agents are preferable.

Examples of the vinylsilane-based silane coupling agent include vinyltriethoxysilane, vinyltrimethoxylane, vinyltris (2-methoxyethoxy) silane, allyltrichlorosilane, allyltriethoxysilane, allyltrimethoxysilane, diethoxymethylvinylsilane, trichlorovinylsilane, etc. Is mentioned.
Examples of the (meth) acryloxysilane-based silane coupling agent include γ-acryloxypropyltrimethoxysilane, 3- (trimethoxysilyl) propyl acrylate, γ-methacryloxypropyltrimethoxysilane, and the like.
Examples of isocyanate silane coupling agents include 3- (triethoxysilyl) propyl isocyanate.
Examples of the epoxysilane-based silane coupling agent include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, and 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane.
Examples of aminosilane-based silane coupling agents include N- (2-aminoethyl) 3-aminopropylmethyldimethoxysilane, N- (2-aminoethyl) 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3 -Aminopropyltrimethoxysilane, 3-aminopropyldiethoxymethylsilane, etc. are mentioned.
Examples of the chloropropylsilane-based silane coupling agent include 3-chloropropyltrichlorosilane.
Examples of the mercaptosilane-based silane coupling agent include (3-mercaptopropyl) triethoxysilane, (3-mercaptopropyl) trimethoxysilane, and the like.
Moreover, the oligomer of these silane coupling agents can also be used as a component (d).

  Among these, (meth) acryloxysilane-based silane coupling agents such as γ-acryloxypropyltrimethoxysilane, 3- (trimethoxysilyl) propyl acrylate, γ-methacryloxypropyltrimethoxysilane, and the like are preferable. N- (2-aminoethyl) 3-aminopropylmethyldimethoxysilane, N- (2-aminoethyl) 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, etc. An aminosilane-based silane coupling agent.

  In the specific example of the resin substrate suitable for the FPC of the present invention described above, the mass ratio of the component (a) and the component (b) is preferably 3: 7 to 7: 3, and preferably 4: 6 to 6: 4 is more preferable.

  When the specific example of the resin substrate suitable for the FPC of the present invention described above contains a urethane prepolymer as the component (c), the mass ratio of the component (c) to the total amount of the components (a) and (b) is 99. : 1 to 40:60 is preferable, 97.5: 2.5 to 50:50 is more preferable, and 95: 5 to 60:40 is more preferable.

  When the specific example of the resin substrate suitable for the FPC of the present invention described above contains a silane coupling agent as the component (d), the mass ratio of the component (d) to the total amount of the components (a) to (c) is It is preferably 99.99: 0.01 to 90:10, more preferably 99.9: 0.1 to 95: 5, and 99.7: 0.3 to 98: 2. Further preferred.

Specific examples of the resin substrate suitable for the FPC of the present invention described above may include any component other than the components (a) to (d) described above. Specific examples of such optional components include fillers used for the purpose of improving the mechanical strength of the resin substrate. Specific examples of such a filler include metals such as silver powder, gold powder and copper powder, metal compounds such as silica, alumina, titania, boron nitride and iron oxide, and organic fillers such as carbon.
When a filler is included as an optional component, the mass ratio of the filler to the total amount of components (a) to (d) is preferably 9: 1 to 1: 9, more preferably 8: 2 to 2. : 8, more preferably 7: 3 to 3: 7.
In addition, the resin substrate suitable for the FPC of the present invention described above is an inorganic fiber such as glass fiber or carbon fiber, or an organic fiber such as aramid fiber, instead of the filler described above or instead of the filler described above. May be included for the purpose of improving the mechanical strength of the resin substrate.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these.

(Examples 1-12, Comparative Examples 1-9)
Sample preparation and measurement method (adhesive film only)
Instead of the adhesive layer of the cover lay film of the present invention, an adhesive film having the same composition as that of the adhesive layer was produced, and its physical properties were evaluated.
After metering and blending each component so as to have the blending ratio (mass%) shown in the following table, they are put into a reaction kettle warmed to 70 ° C. and mixed at normal pressure while rotating at a rotation speed of 300 rpm. I went for 3 hours. When adding a curing agent, the curing agent was added after cooling.
An adhesive film with a support was obtained by applying the varnish containing the resin composition thus obtained to one side of a support (PET film subjected to a release treatment) and drying at 100 ° C. .
In addition, the symbol in a table | surface represents the following, respectively.
Ingredient (A)
OPE2200: Oligophenylene ether (vinyl compound represented by the above general formula (1)) (Mn = 2200), manufactured by Mitsubishi Gas Chemical Co., Ltd.
Ingredient (B)
Tuftec H1052: Polystyrene-poly (ethylene / butylene) block copolymer (styrene amount 20%), Asahi Kasei Corporation Tuftec H1031: Polystyrene-poly (ethylene / butylene) block copolymer (styrene amount 30%), Asahi Kasei Corporation Made by company
Ingredient (C)
Septon 4044: Polystyrene-poly (ethylene-ethylene / propylene) block copolymer (styrene content 32%), manufactured by Kuraray Co., Ltd.
Ingredient (B ')
TR2003: Polystyrene-polybutadiene block copolymer (styrene / butadiene = 43/57), manufactured by JSR Corporation
Ingredient (D)
NC3000H: biphenyl type epoxy resin, manufactured by Nippon Kayaku Co., Ltd.
Ingredient (E)
BMI-70: Bismaleimide, manufactured by Kay Kasei Co., Ltd.
Ingredient (F)
C11ZCN: 1-cyanoethyl-2-undecylimidazole, Shikoku Kasei Kogyo Co., Ltd. 2E4MZ: 2-ethyl-4-methylimidazole, Shikoku Kasei Kogyo Co., Ltd. TPP-MK: tetraphenylphosphonium tetra-p-tolylborate, Hokuko Made by Chemical Industry Co., Ltd.

Compatibility: diluted to an appropriate concentration with a solvent (toluene), applied to a peelable substrate, dried at 100 ° C. for 10 minutes, and then formed into a film having a thickness of 20 μm. Two conditions were observed: the state of the varnish diluted in the solvent and the state of the surface of the product obtained by forming the varnish into a film. Whether or not the varnish was cloudy was visually determined, and the surface of the film was observed with a CCD camera (× 100 times).
When the surface of the varnish is cloudy and the surface of the varnish film is 100 μm or more, or when it cannot be formed into a film, X is marked, and the varnish is cloudy, but the surface of the varnish film The case where there was no speckled pattern of 100 μm or more on the surface of the film was rated as ◯, and the case where the varnish had no turbidity and the surface of the varnish made into a film had no pattern of 100 μm or over was rated as ◎.
Dielectric constant (ε), dielectric loss tangent (tan δ): After the adhesive film was cured by heating at 200 ° C. and peeled from the support, a test piece (40 ± 0.5 mm × 100 ± 2 mm) was cut out from the adhesive film The thickness was measured. The test piece was rolled into a cylindrical shape having a length of 100 mm and a diameter of 2 mm or less, and a dielectric constant (ε) and a dielectric loss tangent (tan δ) were measured by a cavity resonator perturbation method (10 GHz).
Glass transition point Tg: measured by dynamic viscoelasticity measurement (DMA). After the adhesive film was heat-cured at 200 ° C. and peeled from the support, a test piece (10 ± 0.5 mm × 40 ± 1 mm) was cut out from the adhesive film, and the width and thickness of the test piece were measured. Then, it measured by DMS6100 (3 degreeC / min 25-300 degreeC). The peak temperature of tanD was read and used as Tg.
Cross-cut adhesiveness: A copper foil glossy surface was bonded to one side of an adhesive film and thermocompression bonded with a press (200 ° C. 60 min, 10 kgf). After the support is peeled off, the tape is pasted on 100 squares formed when the adhesive film surface is cut into a grid at intervals of 1 mm, and the tape is instantaneously peeled off at an angle of 90 ° to the film surface. It was. At that time, it was determined whether or not the film peeled off the copper foil glossy surface. The results were determined according to the following criteria.
○: 100 squares with no peeling.
X: In 100 squares, even one square has peeling.
Tensile modulus: after heat-curing the adhesive film at 200 ° C. and peeling from the support, 5 test pieces (25 ± 0.5 mm × 220 ± 2 mm) were cut out in the MD direction from the adhesive film, and the thickness was increased. It was measured. The test piece was gripped on an autograph, set at a jig width of 170 mm, and measured up to a stroke of 5 mm at a tensile speed of 1 mm / min. The average value of N = 5 was taken as the measured value.
Curl evaluation: A 50 μm thick LCP film (Bexter (registered trademark) CT-Z (manufactured by Kuraray Co., Ltd.)) was cut into 50 ± 0.5 mm squares, and an adhesive film cut into the same size was placed on one side of the LCP film. Thermocompression bonding was performed with a press machine (200 ° C. 60 min, 10 kgf). The support was peeled off and placed on a horizontal surface of a flat desk with the surface to which the adhesive film was attached facing up, and the degree of curling was observed. The maximum value of the test piece floating height from the horizontal plane of the desk was defined as D, and the determination was made according to the following criteria.
◯: The test piece is not cylindrical and D ≦ 15 mm.
Δ: The test piece is not cylindrical and 15 mm <D.
X: The test piece has become cylindrical.

Examples 1 to 11 were excellent in compatibility, curl, cross-cut adhesiveness, electrical characteristics in the high frequency region (dielectric constant (ε), dielectric loss tangent (tan δ)), and tensile elastic modulus. In particular, Examples 1, 3-8, and 10 were particularly excellent in compatibility. Further, in Example 5 in which B / C was increased as compared with Example 1, the tensile elastic modulus could be lowered. In Example 6 in which B / C was further increased as compared with Example 5, the tensile elastic modulus could be further reduced.
Further, in Example 8 in which the content of the epoxy resin as the component (D) was reduced as compared with Example 1, the dielectric loss tangent (tan δ) could be further reduced.
In Comparative Example 1 in which a polystyrene / polybutadiene block copolymer was used as the thermoplastic elastomer in place of the components (B) and (C), the tensile elastic modulus increased and the curl deteriorated.
In Comparative Example 2 not containing the component (B), the tensile elastic modulus was increased and the curl was deteriorated.
In Comparative Example 3 in which the mass ratio of each component was less than (A + E) / (B + C) = 0.81, the cross-cut adhesiveness was inferior.
In Comparative Example 4 in which the mass ratio of each component exceeded (A + E) / (B + C) = 1.00, the compatibility was lowered, the tensile modulus was increased, and the curl was deteriorated.
In Comparative Examples 5 and 6 in which the mass ratio (B) / (C) of the components (B) and (C) was less than 1.00, the tensile elastic modulus increased and the curl deteriorated.
Comparative Example 7 in which the mass ratio of the components (B) and (C) (B) / (C) = 4.00 was inferior in compatibility and cross-cut adhesion.
In Comparative Example 8 containing no component (C), the compatibility was lowered and a flat film could not be obtained. Therefore, evaluation of curl etc. was not implemented.
In Comparative Example 9 in which the content of the epoxy resin of component (D) was more than 6 parts by mass with respect to component (A), the compatibility was lowered. Further, the dielectric loss tangent (tan δ) of the heat-cured product of the adhesive film was more than 0.004.

Sample preparation and measurement method (a cover layer film having a two-layer structure in which an adhesive layer is formed on one side of an organic film having a melting point higher than the thermosetting temperature of the adhesive layer.)
By applying a varnish containing a resin composition (Example 5) obtained by the same procedure as described above to one side of an organic film having a melting point higher than the thermosetting temperature of the resin composition, and drying at 100 ° C., A cover layer film having a two-layer structure in which an adhesive layer was formed on one side of the organic film was obtained.
As another method, an adhesive film with a support obtained in the same procedure as described above (Example 5) is placed on one side of an organic film having a melting point higher than the thermosetting temperature of the adhesive film at 120 ° C. The cover lay film having a two-layer structure in which an adhesive layer was formed on one side of the organic film was obtained by temporary pressure bonding.
In addition, as an organic film, Bexter (trademark) CT-Z (made by Kuraray Co., Ltd.) and thickness 25 micrometers were used as an LCP film. The melting point of the LCP film was 335 ° C. The thickness of the adhesive layer was 15 μm and 25 μm.
The following evaluation was carried out on the produced two-layer coverlay film.
Dielectric constant (ε), dielectric loss tangent (tan δ): A cover layer film having a two-layer structure is heated and cured at 200 ° C., and a test piece (40 ± 0.5 mm × 100 ± 2 mm) is formed from the cover layer film having the two-layer structure. Cut out and measured for thickness. The test piece was rolled into a cylindrical shape having a length of 100 mm and a diameter of 2 mm or less, and a dielectric constant (ε) and a dielectric loss tangent (tan δ) were measured by a cavity resonator perturbation method (10 GHz).
Peel strength: A copper foil glossy surface was bonded to the adhesive layer of a two-layer coverlay film and thermocompression bonded with a press machine (200 ° C. 60 min, 10 kgf). This test piece was cut into a width of 10 mm, the copper foil was peeled off by an autograph, and the peel strength was measured. For the measurement results, the average value of each N = 5 was calculated.
Cross-cut adhesion: A copper foil glossy surface was bonded to the adhesive layer of a two-layer coverlay film, and thermocompression bonded with a press (200 ° C., 60 min, 10 kgf). A tape is applied on 100 squares formed when the coverlay film is cut into a grid at 1 mm intervals on the organic film (LCP film) surface, and the tape is attached at an angle of 90 ° to the organic film (LCP film) surface. I peeled it off momentarily. At that time, it was determined whether or not the organic film (LCP film) peeled off from the glossy surface of the copper foil.

The cover lay film having an adhesive layer thickness of 15 μm had a dielectric constant (ε) of 2.9 and a dielectric loss tangent (tan δ) of 0.0024. The peel strength was 6.58 N / cm. No peeling occurred in the cross-cut adhesion evaluation.
The cover lay film having an adhesive layer thickness of 25 μm had a dielectric constant (ε) of 2.8 and a dielectric loss tangent (tan δ) of 0.0026. The peel strength was 6.77 N / cm. No peeling occurred in the cross-cut adhesion evaluation.
From these results, all the two-layer coverlay films produced by changing the thickness of the adhesive layer have high frequency region electrical characteristics (dielectric constant ε, dielectric loss tangent tan δ), peel strength, and cross-cut adhesiveness. It was confirmed to be excellent.
The dielectric constant (ε) of the LCP film alone was 3.2, and the dielectric loss tangent (tan δ) was 0.0022. The dielectric constant (ε) of the adhesive layer (adhesive film) alone (thickness: 25 μm) was 2.3, and the dielectric loss tangent (tan δ) was 0.0030.

Further, in the same procedure as described above, a cover layer film having a two-layer structure was produced using a PI film as an organic film, and dielectric constant (ε) and dielectric loss tangent (tan δ) were evaluated.
The following was used as the PI film.
Xenomax (registered trademark), manufactured by Toyobo Co., Ltd., thickness: 12.5 μm
Kapton (registered trademark) 100EN, manufactured by Toray DuPont Co., Ltd., thickness 25 μm
Kapton (registered trademark) 300H, manufactured by Toray DuPont Co., Ltd., thickness 77 μm,
The results are as follows.
Xenomax (R) alone Dielectric constant ([epsilon]): 3.6
Dissipation factor (tan δ): 0.0114
Two-layer coverlay film Dielectric constant (ε): 2.8
Dissipation factor (tan δ): 0.0059
Kapton (R) 100EN alone Dielectric constant ([epsilon]): 3.3
Dissipation factor (tan δ): 0.0086
Two-layer coverlay film Dielectric constant (ε): 2.8
Dissipation factor (tan δ): 0.0059
Kapton (R) 300H alone Dielectric constant ([epsilon]): 3.3
Dissipation factor (tan δ): 0.0144
Cover layer film having a two-layer structure Dielectric constant (ε): 3.0
Dissipation factor (tan δ): 0.0108
From these results, even in the case of a two-layer coverlay film produced using different types of PI film as the organic film and changing the thickness of the adhesive layer, the electrical characteristics (dielectric constant ε, dielectric loss tangent) in the high frequency region It was confirmed that tan δ) was excellent.

Method for Producing Printed Wiring Plate Based on FPC Containing Components (a) and (b) as Main Components A resin composition containing the following components was used for producing a resin substrate for FPC.
Component (a): OPE2st: Oligophenylene ether (vinyl compound represented by the above general formula (1)) (Mn = 1200), 54.3 parts manufactured by Mitsubishi Gas Chemical Co., Ltd.
Component (b): Polystyrene-polybutadiene block copolymer (manufactured by JSR Corporation: “TR2003”: mass average molecular weight of about 100,000, styrene content of 43% by mass) 36.2 parts
Component (c): Urethane prepolymer In a 2000 ml four-necked flask equipped with a reflux condenser, a stirring blade, and a thermometer, 600 g of toluene, polyol (“Epol PIP-H”, manufactured by Idemitsu Petrochemical; sp = 8.20) 633.3 g, 1,4-butanediol 33.3 g, and isophorone diisocyanate 233.3 g were charged and uniformly dissolved, and then 0.06 g of triethylenediamine was added as a catalyst. The flask was heated so that the temperature inside the flask became 70 ° C. to 80 ° C., and the urethanization reaction was carried out for 7 hours. Then, it cooled and the toluene solution of the urethane prepolymer whose free isocyanate amount per solid content is 3.5 mass% was obtained. 9 copies
Component (d): Silane coupling agent γ-acryloxypropyltrimethoxysilane (“KBM-5103”, manufactured by Shin-Etsu Chemical Co., Ltd.) 0.5 part

  Each of the above components was dry-mixed at a peripheral speed of 400 rpm using a three-one motor (manufactured by Shinto Kagaku Co., Ltd., BLW1200) to prepare a resin composition. The resin composition was added to the solvent methyl ethyl ketone and heated and stirred to prepare a varnish (solid content concentration of about 30% by mass). The varnish was applied to a PET film (thickness 50 μm) as a support with a gravure coater, dried at 100 ° C. for 10 minutes, allowed to cool, and peeled from the PET film to obtain a resin substrate for FPC. The thickness of the resin substrate was 30 μm.

  Copper foil was bonded to both surfaces of the resin substrate obtained by the above procedure with the roughened surface inside, and thermocompression bonded with a press machine (200 ° C. 60 min, 10 kgf). One side or both sides of the thermocompressed copper foil was etched to draw a wiring pattern, and a resin substrate with wiring was prepared. The two-layered cover lay film obtained in the above procedure is placed on the wiring pattern side of the resin substrate with wiring so that the adhesive layers face each other and thermocompression-bonded with a press (200 ° C. 60 min, 10 kgf). A printed wiring board was produced.

Claims (13)

(A) a vinyl compound represented by the following general formula (1),
(In the formula, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ may be the same or different and each represents a hydrogen atom, a halogen atom, an alkyl group, a halogenated alkyl group or a phenyl group. -(O-X-O)-is represented by the following structural formula (2).

R ₈ , R ₉ , R ₁₀ , R ₁₄ , and R ₁₅ may be the same or different and are a halogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group. R ₁₁ , R ₁₂ and R ₁₃ may be the same or different and are a hydrogen atom, a halogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group. -(YO)-is a structure in which one type of structure defined by the following structural formula (3) or two or more types of structures defined by the following structural formula (3) are randomly arranged.

R ₁₆ and R ₁₇ may be the same or different and are a halogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group. R ₁₈ and R ₁₉ may be the same or different and are a hydrogen atom, a halogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group. Z is an organic group having 1 or more carbon atoms, and may contain an oxygen atom, a nitrogen atom, a sulfur atom, or a halogen atom. a and b each represents an integer of 0 to 300, at least one of which is not 0. c and d represent an integer of 0 or 1. )
(B) polystyrene-poly (ethylene / butylene) block copolymer,
(C) polystyrene-poly (ethylene-ethylene / propylene) block copolymer,
(D) epoxy resin,
(E) Bismaleimide is included, and the mass ratio of each component is (A + E) / (B + C) = 0.81 or more and 1.00 or less, and (B) / (C) = 1.00 or more and 4.00 or less. And the adhesive layer which contains the said component (D) 1-10 mass% with respect to the total mass of the said components (A)-(E),
An organic film having a melting point higher than the thermosetting temperature of the adhesive layer, a dielectric constant (ε) of 4.0 or less, and a dielectric loss tangent (tan δ) of 0.02 or less in a frequency range of 1 to 10 GHz. A cover lay film formed on one side. -(OXO)-of the component (A) is represented by the following structural formula (4), and-(YO)-of the component (A) is represented by the following structural formula (5), or The cover according to claim 1, having a structure represented by the following structural formula (6), or a structure in which the structure represented by the following structural formula (5) and the structure represented by the following structural formula (6) are randomly arranged. Ray film.

  The coverlay film according to claim 2, wherein — (YO) — of the component (A) has a structure represented by the structural formula (6).   The coverlay film according to any one of claims 1 to 3, wherein a minimum melt viscosity of the adhesive layer in a temperature range of 150 to 200 ° C is 2000 Pa · s to 10,000 Pa · s.   5. The dielectric constant (ε) is 3.5 or less and the dielectric loss tangent (tan δ) is 0.02 or less in a region of a frequency of 1 to 10 GHz after the thermosetting of the adhesive layer. The coverlay film according to crab.   The dielectric constant (ε) of the adhesive layer is 2.5 or less and the dielectric loss tangent (tan δ) is 0.004 or less in the region of frequency 1 to 10 GHz after the thermosetting of the adhesive layer. The coverlay film in any one of -5.   The coverlay film according to any one of claims 1 to 6, wherein the organic film is produced using any one of a liquid crystal polymer, polyimide, polyethylene naphthalate, and polytetrafluoroethylene.   Either of the liquid crystal polymer, polyimide, and polyethylene naphthalate, on the wiring pattern side of the resin substrate with wiring, wherein the wiring pattern is formed on the main surface of the resin substrate. The flexible printed wiring board, wherein the cover lay film according to 1 is disposed so that the adhesive layers face each other, and the resin substrate with wiring and the cover lay film are integrated by thermocompression bonding. A resin substrate with wiring in which a wiring pattern is formed on the main surface of a resin substrate mainly composed of a vinyl compound (a) represented by the following general formula (1) and rubber and / or thermoplastic elastomer (b) The cover lay film according to any one of claims 1 to 7 is arranged on the wiring pattern side so that the adhesive layer faces each other, and the resin substrate with wiring and the cover lay film are integrated by thermocompression bonding. A flexible printed wiring board characterized by the above.
(In the formula, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ may be the same or different and each represents a hydrogen atom, a halogen atom, an alkyl group, a halogenated alkyl group or a phenyl group. -(O-X-O)-is represented by the following structural formula (2).

R ₈ , R ₉ , R ₁₀ , R ₁₄ , and R ₁₅ may be the same or different and are a halogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group. R ₁₁ , R ₁₂ and R ₁₃ may be the same or different and are a hydrogen atom, a halogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group. -(YO)-is a structure in which one type of structure defined by the following structural formula (3) or two or more types of structures defined by the following structural formula (3) are randomly arranged.

R ₁₆ and R ₁₇ may be the same or different and are a halogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group. R ₁₈ and R ₁₉ may be the same or different and are a hydrogen atom, a halogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group. Z is an organic group having 1 or more carbon atoms, and may contain an oxygen atom, a nitrogen atom, a sulfur atom, or a halogen atom. a and b each represents an integer of 0 to 300, at least one of which is not 0. c and d represent an integer of 0 or 1. ) A method for producing a coverlay film in which an adhesive layer is formed on one side of an organic film,
The adhesive layer is
(A) a vinyl compound represented by the following general formula (1),
(In the formula, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ may be the same or different and each represents a hydrogen atom, a halogen atom, an alkyl group, a halogenated alkyl group or a phenyl group. -(O-X-O)-is represented by the following structural formula (2).

R ₈ , R ₉ , R ₁₀ , R ₁₄ , and R ₁₅ may be the same or different and are a halogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group. R ₁₁ , R ₁₂ and R ₁₃ may be the same or different and are a hydrogen atom, a halogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group. -(YO)-is a structure in which one type of structure defined by the following structural formula (3) or two or more types of structures defined by the following structural formula (3) are randomly arranged.

R ₁₆ and R ₁₇ may be the same or different and are a halogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group. R ₁₈ and R ₁₉ may be the same or different and are a hydrogen atom, a halogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group. Z is an organic group having 1 or more carbon atoms, and may contain an oxygen atom, a nitrogen atom, a sulfur atom, or a halogen atom. a and b each represents an integer of 0 to 300, at least one of which is not 0. c and d represent an integer of 0 or 1. )
(B) polystyrene-poly (ethylene / butylene) block copolymer,
(C) polystyrene-poly (ethylene-ethylene / propylene) block copolymer,
(D) epoxy resin,
(E) Bismaleimide is included, and the mass ratio of each component is (A + E) / (B + C) = 0.81 or more and 1.00 or less, and (B) / (C) = 1.00 or more and 4.00 or less. And the varnish which consists of a resin composition which contains the said component (D) 1-10 mass% with respect to the total mass of the said components (A)-(E),
An organic film having a melting point higher than the thermosetting temperature of the resin composition, a dielectric constant (ε) of 4.0 or less, and a dielectric loss tangent (tan δ) of 0.02 or less in a frequency range of 1 to 10 GHz. A method for producing a coverlay film, wherein the coverlay film is formed by applying to one side and drying. A method for producing a coverlay film in which an adhesive layer is formed on one side of an organic film,
(A) a vinyl compound represented by the following general formula (1),
(In the formula, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ may be the same or different and each represents a hydrogen atom, a halogen atom, an alkyl group, a halogenated alkyl group or a phenyl group. -(O-X-O)-is represented by the following structural formula (2).

R ₈ , R ₉ , R ₁₀ , R ₁₄ , and R ₁₅ may be the same or different and are a halogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group. R ₁₁ , R ₁₂ and R ₁₃ may be the same or different and are a hydrogen atom, a halogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group. -(YO)-is a structure in which one type of structure defined by the following structural formula (3) or two or more types of structures defined by the following structural formula (3) are randomly arranged.

R ₁₆ and R ₁₇ may be the same or different and are a halogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group. R ₁₈ and R ₁₉ may be the same or different and are a hydrogen atom, a halogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group. Z is an organic group having 1 or more carbon atoms, and may contain an oxygen atom, a nitrogen atom, a sulfur atom, or a halogen atom. a and b each represents an integer of 0 to 300, at least one of which is not 0. c and d represent an integer of 0 or 1. )
(B) polystyrene-poly (ethylene / butylene) block copolymer,
(C) polystyrene-poly (ethylene-ethylene / propylene) block copolymer,
(D) epoxy resin,
(E) Bismaleimide is included, and the mass ratio of each component is (A + E) / (B + C) = 0.81 or more and 1.00 or less, and (B) / (C) = 1.00 or more and 4.00 or less. And an adhesive film is produced from the resin composition containing 1 to 10% by mass of the component (D) with respect to the total mass of the components (A) to (E), and the adhesive film, An organic film having a melting point higher than the thermosetting temperature of the adhesive film, a dielectric constant (ε) of 4.0 or less, and a dielectric loss tangent (tan δ) of 0.02 or less in a frequency range of 1 to 10 GHz. A method for producing a coverlay film, wherein the adhesive layer is formed by bonding. Providing a wiring pattern on the main surface of a resin substrate mainly composed of liquid crystal polymer, polyimide, and polyethylene naphthalate to produce a resin substrate with wiring,
The cover lay film according to any one of claims 1 to 7 is disposed on the wiring pattern side of the resin substrate with wiring so that the adhesive layer is opposed to the resin substrate, and the resin substrate with wiring is formed by thermocompression bonding. A method for producing a flexible printed wiring board, wherein the coverlay film and the coverlay film are integrated. A wiring substrate is provided on the main surface of the resin substrate mainly composed of the vinyl compound represented by the following general formula (1), and rubber and / or thermoplastic elastomer, to produce a resin substrate with wiring,
The cover lay film according to any one of claims 1 to 7 is disposed on the wiring pattern side of the resin substrate with wiring so that the adhesive layer is opposed to the resin substrate, and the resin substrate with wiring is formed by thermocompression bonding. A method for producing a flexible printed wiring board, wherein the coverlay film and the coverlay film are integrated.
(In the formula, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ may be the same or different and each represents a hydrogen atom, a halogen atom, an alkyl group, a halogenated alkyl group or a phenyl group. -(O-X-O)-is represented by the following structural formula (2).

R ₈ , R ₉ , R ₁₀ , R ₁₄ , and R ₁₅ may be the same or different and are a halogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group. R ₁₁ , R ₁₂ and R ₁₃ may be the same or different and are a hydrogen atom, a halogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group. -(YO)-is a structure in which one type of structure defined by the following structural formula (3) or two or more types of structures defined by the following structural formula (3) are randomly arranged.

R ₁₆ and R ₁₇ may be the same or different and are a halogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group. R ₁₈ and R ₁₉ may be the same or different and are a hydrogen atom, a halogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group. Z is an organic group having 1 or more carbon atoms, and may contain an oxygen atom, a nitrogen atom, a sulfur atom, or a halogen atom. a and b each represents an integer of 0 to 300, at least one of which is not 0. c and d represent an integer of 0 or 1. )