JP2023029400A - Conductor substrate, wiring board, stretchable device, and method for manufacturing wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conductor substrate having high stretchability and a low dielectric loss tangent.

SOLUTION: The conductor substrate includes a stretchable resin layer and a conductor plating film provided on the stretchable resin layer. The stretchable resin layer contains a cured product of a resin composition containing (A) a rubber component, (B) a crosslinking component having an epoxy group, and (C) an ester-based curing agent. The content of the rubber component (A) in the resin composition is 60-95 mass% based on the total amount of the rubber component (A), the crosslinking component (B), and the ester-based curing agent (C).

SELECTED DRAWING: None

COPYRIGHT: (C)2023,JPO&INPIT

Description

One aspect of the present invention relates to a wiring board that can have high elasticity and a method for manufacturing the same. Another aspect of the present invention relates to a conductor substrate that can be used to form the above wiring substrate. Yet another aspect of the present invention relates to a stretchable device using the wiring substrate.

In recent years, in the fields of wearable devices and healthcare-related devices, there has been a demand for flexibility and stretchability so that they can be used, for example, along curved surfaces or joints of the body, and are less likely to cause poor connection when attached and detached. In order to configure such equipment, a wiring board or base material with high elasticity is required.

Patent Literature 1 describes a method of encapsulating a semiconductor element such as a memory chip using an elastic resin composition. In Patent Document 1, application of a stretchable resin composition to sealing applications is mainly studied.

WO2016/080346

As described in Patent Document 1, by imparting stretchability to the sealing material, it has become possible to realize a member having stretchability, which has been difficult with conventional sealing materials. On the other hand, since the base material does not have stretchability, it has been difficult to impart higher stretchability. Therefore, there is a demand for a wiring board having higher stretchability.

In addition, from the viewpoint of improving heat resistance, the use of a cross-linking component having a reactive functional group is being studied as a material for producing a base material of a wiring board. However, the use of a cross-linking component having a reactive functional group tends to increase the dielectric loss tangent of the resulting base material, which tends to increase the transmission loss of wiring provided on the base material.

Under such circumstances, an object of one aspect of the present invention is to provide a conductive substrate having high stretchability and low dielectric loss tangent, a wiring substrate using the same, a stretchable device, and a method for manufacturing a wiring substrate. and

In order to achieve the above object, one aspect of the present invention is a conductive substrate having a stretchable resin layer and a conductive foil provided on the stretchable resin layer, wherein the stretchable resin layer comprises: Provided is a conductor substrate including a cured product of a resin composition containing (A) a rubber component, (B) a cross-linking component having an epoxy group, and (C) an ester curing agent.

Another aspect of the present invention is a conductor substrate having a stretchable resin layer and a conductive plating film provided on the stretchable resin layer, wherein the stretchable resin layer comprises (A) a rubber component and (B) a cross-linking component having an epoxy group, and (C) an ester curing agent.

According to the above-mentioned conductor board, high stretchability can be obtained by using (A) the stretchable resin layer containing the rubber component as the base material. Conventionally, when a cross-linking component having a reactive functional group is used as a material for producing a stretchable resin layer, the dielectric loss tangent increases because the cross-linking component generates hydroxyl groups during the curing reaction. It is believed that there is. Since the hydroxyl group is a functional group with a small volume and high polarizability, the dielectric loss tangent of the material having the hydroxyl group increases as a whole. On the other hand, by using a combination of (B) a crosslinking component having an epoxy group as a crosslinking component and (C) an ester-based curing agent as a curing agent, the generation of hydroxyl groups during the curing reaction of the crosslinking component is greatly suppressed. The inventors have found that it is possible. This is because the curing reaction between the epoxy group of the cross-linking component and the ester-based curing agent does not accompany the formation of hydroxyl groups, and the formation of hydroxyl groups is difficult even after curing. Furthermore, their cured products do not adversely affect stretchability. Therefore, according to the conductive substrate having the above configuration, a low dielectric loss tangent can be realized while maintaining high stretchability and using a cross-linking component capable of improving heat resistance.

Another aspect of the present invention provides a wiring substrate including the conductor substrate of the present invention, wherein the conductor foil or conductor plating film forms a wiring pattern. The wiring board is obtained by forming a wiring pattern from the conductor foil or the conductor plating film of the conductor board of the present invention, and is provided with the elastic resin layer having the specific configuration, and thus has high elasticity. At the same time, the use of the cross-linking component can provide high heat resistance and low dielectric loss tangent, thereby sufficiently reducing the transmission loss of the wiring pattern.

Another aspect of the present invention provides a stretchable device including the wiring board of the present invention and an electronic element mounted on the wiring board. The stretchable device includes the wiring board of the present invention, and includes the stretchable resin layer having the specific configuration. It is possible to have a low dielectric loss tangent while maintaining the property, and the transmission loss of the wiring pattern is sufficiently reduced.

Another aspect of the present invention includes a conductor substrate having an elastic resin layer and a conductor foil or conductor plating film provided on the elastic resin layer, wherein the conductor foil or conductor plating film is a wiring pattern. The conductor substrate of the present invention, which is used to form a wiring substrate, is provided.

Another aspect of the present invention includes the steps of preparing a laminate having a stretchable resin layer and a conductor foil laminated on the stretchable resin layer, forming an etching resist on the conductor foil, exposing the etching resist and developing the etching resist after exposure to form a resist pattern covering a portion of the conductor foil; and removing a portion of the conductor foil not covered by the resist pattern. and a step of removing the resist pattern.

Another aspect of the present invention includes a step of forming a plating resist on a stretchable resin layer, exposing the plating resist, developing the exposed plating resist, and partially removing the stretchable resin layer. forming a covering resist pattern; forming a conductive plating film by electroless plating on the surface of the stretchable resin layer not covered by the resist pattern; removing the resist pattern; to provide a method for manufacturing the wiring board of the present invention.

Another aspect of the present invention includes the steps of forming a conductor plating film on an elastic resin layer by electroless plating, forming a plating resist on the conductor plating film, exposing the plating resist to light, and exposing the plating resist to light. developing the plating resist to form a resist pattern covering a portion of the elastic resin layer; and electroplating a portion of the conductive plating film not covered by the resist pattern with electroplating. forming a further film; removing the resist pattern; and removing a portion of the conductor plating film formed by electroless plating that is not covered by the conductor plating film formed by electrolytic plating. and a method for manufacturing the wiring board of the present invention.

Another aspect of the present invention includes a step of forming an etching resist on a conductive plating film formed on a stretchable resin layer, exposing the etching resist, developing the etching resist after exposure, and forming a resist pattern covering a part of the elastic resin layer; removing the conductive plating film in a portion not covered by the resist pattern; and removing the resist pattern. A method for manufacturing the wiring substrate of the present invention is provided.

By the manufacturing method described above, it is possible to efficiently manufacture the wiring board of the present invention in which the conductor foil or conductor plating film forms the wiring pattern.

ADVANTAGE OF THE INVENTION According to one aspect of the present invention, it is possible to provide a conductive substrate having high stretchability and low dielectric loss tangent, a wiring substrate using the same, a stretchable device, and a method for manufacturing a wiring substrate.

It is a stress-strain curve showing an example of recovery rate measurement. It is a top view which shows one Embodiment of a wiring board. It is a graph which shows the temperature profile of a heat resistance test. 2 is a diagram showing infrared absorption spectra of a stretchable resin layer before and after curing in Comparative Example 1. FIG. 2 is a diagram showing infrared absorption spectra of stretchable resin layers after curing in Examples 1 and 3 and Comparative Example 1. FIG.

Several embodiments of the invention are described in detail below. However, the present invention is not limited to the following embodiments.

A conductor substrate according to one embodiment has a stretchable resin layer and conductor layers provided on one side or both sides of the stretchable resin layer, wherein the stretchable resin layer comprises (A) a rubber component, ( It includes a cured product of a resin composition containing B) a cross-linking component having an epoxy group and (C) an ester-based curing agent. A wiring board according to one embodiment includes a stretchable resin layer containing a cured product of the resin composition, and a conductor layer provided on one side or both sides of the stretchable resin layer and forming a wiring pattern. . The conductor layer can be a conductor foil or a conductor plating film.

<Conductor board>
[Conductor foil]
The elastic modulus of the conductor foil may be 40-300 GPa. Since the elastic modulus of the conductor foil is 40 to 300 GPa, the conductor foil tends to be less likely to break due to the elongation of the wiring board. From the same point of view, the elastic modulus of the conductor foil may be 50 GPa or more or 60 GPa or more, or may be 280 GPa or less or 250 GPa or less. The elastic modulus of the conductor foil here can be a value measured by a resonance method.

The conductor foil can be a metal foil. Metal foils include copper foil, titanium foil, stainless steel foil, nickel foil, permalloy foil, 42 alloy foil, kovar foil, nichrome foil, beryllium copper foil, phosphor bronze foil, brass foil, nickel silver foil, aluminum foil, tin foil, Lead foil, zinc foil, solder foil, iron foil, tantalum foil, niobium foil, molybdenum foil, zirconium foil, gold foil, silver foil, palladium foil, monel foil, inconel foil, hastelloy foil and the like. The conductor foil may be selected from copper foil, gold foil, nickel foil, and iron foil from the viewpoint of appropriate elastic modulus and the like. From the viewpoint of wiring formability, the conductor foil may be copper foil. A wiring pattern can be easily formed on the copper foil by photolithography without impairing the properties of the stretchable resin layer.

The copper foil is not particularly limited, and for example, electrolytic copper foil and rolled copper foil used for copper-clad laminates, flexible wiring boards and the like can be used. Commercially available electrolytic copper foils include, for example, F0-WS-18 (manufactured by Furukawa Electric Co., Ltd., trade name), NC-WS-20 (manufactured by Furukawa Electric Co., Ltd., trade name), YGP-12 (Nippon Denki Co., Ltd. (manufactured by Furukawa Electric Co., Ltd., trade name), GTS-18 (manufactured by Furukawa Electric Co., Ltd., trade name), and F2-WS-12 (manufactured by Furukawa Electric Co., Ltd., trade name). Examples of rolled copper foils include TPC foil (manufactured by JX Metals Co., Ltd., trade name), HA foil (manufactured by JX Metals Co., Ltd., trade name), HA-V2 foil (manufactured by JX Metals Co., Ltd., trade name), and C1100R. (manufactured by Mitsui Sumitomo Metal Mining Copper & Copper Co., Ltd., trade name). From the viewpoint of adhesion with the stretchable resin layer, a copper foil that has undergone a roughening treatment may be used. From the viewpoint of folding resistance, a rolled copper foil may be used.

The metal foil may have a roughened surface formed by roughening treatment. In this case, the metal foil is usually provided on the stretchable resin layer such that the roughened surface is in contact with the stretchable resin layer. From the viewpoint of adhesion between the elastic resin layer and the metal foil, the roughened surface may have a surface roughness Ra of 0.1 to 3 μm, or 0.2 to 2.0 μm. In order to easily form fine wiring, the roughened surface may have a surface roughness Ra of 0.3 to 1.5 μm.

The surface roughness Ra can be measured, for example, using a surface profiler Wyko NT9100 (manufactured by Veeco) under the following conditions.
Measurement conditions Internal lens: 1x External lens: 50x Measurement range: 0.120 x 0.095 mm
Measurement depth: 10 μm
Measurement method: vertical scanning interference method (VSI method)

The thickness of the conductor foil is not particularly limited, but may be 1 to 50 μm. A wiring pattern can be formed more easily as the thickness of the conductor foil is 1 μm or more. Etching and handling are particularly easy when the thickness of the conductor foil is 50 μm or less.

The conductor foil is provided on one side or both sides of the elastic resin layer. By providing conductor foils on both sides of the elastic resin layer, it is possible to suppress warping due to heating for curing or the like.

The method of providing the conductor foil is not particularly limited. There is a method of coating a carrier film to form a resin layer (stretchable resin layer before curing), and laminating the formed resin layer on a conductor foil.

[Conductor plating film]
The conductive plating film can be formed by a normal plating method used for additive or semi-additive methods. For example, after performing a plating catalyst application treatment for adhering palladium, the elastic resin layer is immersed in an electroless plating solution to form an electroless plating layer (conductor layer) having a thickness of 0.3 to 1.5 μm on the entire surface of the primer. precipitate out. If necessary, further electroplating (electroplating) can be performed to adjust the required thickness. Any electroless plating solution can be used as the electroless plating solution used for electroless plating, and there is no particular limitation. As for electrolytic plating, it is possible to adopt a normal method, and there is no particular limitation. The conductor plated film (electroless plated film, electrolytic plated film) may be a copper plated film from the viewpoint of cost and resistance.

Furthermore, unnecessary portions can be removed by etching to form a circuit layer. The etchant used for etching can be appropriately selected depending on the type of plating. For example, when the conductor is plated with copper, the etchant used for etching may be, for example, a mixed solution of concentrated sulfuric acid and hydrogen peroxide, or a ferric chloride solution.

Asperities may be formed in advance on the stretchable resin layer in order to improve the adhesive strength with the conductive plating film. As a method of forming unevenness, for example, a method of transferring a roughened surface of a copper foil can be used. As the copper foil, for example, YGP-12 (manufactured by Nippon Denki Co., Ltd., trade name), GTS-18 (manufactured by Furukawa Electric Co., Ltd., trade name) or F2-WS-12 (manufactured by Furukawa Electric Co., Ltd., trade name ) can be used.

Techniques for transferring the roughened surface of the copper foil include, for example, a method of directly applying a resin composition for forming a stretchable resin layer on the roughened surface of the copper foil, and a method of forming a stretchable resin layer. There is a method in which a resin layer (stretchable resin layer before curing) is formed on a copper foil after coating the resin composition of (1) on a carrier film. By forming conductive plating films on both surfaces of the stretchable resin layer, it is possible to suppress warping caused by heating for curing or the like.

A surface treatment may be applied to the stretchable resin layer for the purpose of achieving high adhesion with the conductive plating film. Examples of the surface treatment include roughening treatment (desmear treatment), UV treatment, and plasma treatment, which are used in general wiring board manufacturing processes.

As the desmear treatment, a method used in a general wiring board manufacturing process may be used, and for example, an aqueous solution of sodium permanganate may be used.

[Elastic resin layer]
The stretchable resin layer can have stretchability such that the recovery rate after being tensile-deformed to a strain of 20% is 80% or more. This recovery rate is obtained in a tensile test using a measurement sample of the stretchable resin layer. Let X be the strain (displacement amount) applied in the first tensile test, and Y be the difference between the position when the load starts to be applied when the tensile test is performed again after returning to the initial position and X, and the formula: R ( %) = (Y/X) x 100 is defined as the recovery rate. Recovery can be measured with X as 20%. FIG. 1 is a stress-strain curve showing an example of recovery rate measurement. From the viewpoint of resistance to repeated use, the recovery rate may be 80% or more, 85% or more, or 90% or more. The definitional upper limit of the recovery rate is 100%.

The elastic modulus (tensile elastic modulus) of the elastic resin layer may be 0.1 MPa or more and 1000 MPa or less. When the elastic modulus is 0.1 MPa or more and 1000 MPa or less, the handleability and flexibility of the substrate tend to be particularly excellent. From this point of view, the elastic modulus may be 0.3 MPa or more and 100 MPa or less, or 0.5 MPa or more and 50 MPa or less.

The elastic resin layer may have an elongation at break of 100% or more. When the elongation at break is 100% or more, sufficient stretchability tends to be obtained. From this point of view, the elongation at break may be 150% or more, 200% or more, 300% or more, or 500% or more. Although the upper limit of the elongation at break is not particularly limited, it is usually about 1000% or less.

The dielectric loss tangent (Df) of the elastic resin layer may be 0.004 or less. When the dielectric loss tangent is 0.004 or less, there is a tendency that the transmission loss of the wiring pattern provided on the elastic resin layer can be sufficiently reduced. From this point of view, the dielectric loss tangent may be 0.0035 or less, 0.003 or less, or 0.0025 or less. Although the lower limit of the dielectric loss tangent is not particularly limited, it is usually about 0.0005 or more.

The elastic resin layer may have a dielectric constant (Dk) of 4.0 or less. When the dielectric constant is 4.0 or less, there is a tendency that the transmission loss of the wiring pattern provided on the stretchable resin layer can be sufficiently reduced. From this point of view, the dielectric constant may be 3.5 or less, 3.0 or less, or 2.5 or less.

The stretchable resin layer may have no absorption peak attributed to the stretching vibration of hydroxyl groups in its infrared absorption spectrum. As a result, the dielectric loss tangent of the elastic resin layer is sufficiently reduced, and there is a tendency that the transmission loss of the wiring pattern provided on the elastic resin layer can be sufficiently reduced.

The stretchable resin layer is a cured product of a resin composition (curable resin composition) containing (A) a rubber component, (B) a cross-linking component having an epoxy group, and (C) an ester curing agent. include. That is, the elastic resin layer contains (B) a crosslinked polymer of a crosslinking component having an epoxy group. Stretchability is easily imparted to the stretchable resin layer mainly by the rubber component (A).

(A) The rubber component includes, for example, acrylic rubber, isoprene rubber, butyl rubber, styrene-butadiene rubber, butadiene rubber, acrylonitrile-butadiene rubber, silicone rubber, urethane rubber, chloroprene rubber, ethylene-propylene rubber, fluororubber, vulcanized rubber, epichlorohydrin rubber, and at least one rubber selected from the group consisting of chlorinated butyl rubber. A rubber component having low gas permeability may be used from the viewpoint of protecting the wiring from damage due to moisture absorption or the like. From this point of view, the rubber component (A) may contain at least one selected from styrene-butadiene rubber, butadiene rubber, and butyl rubber. By using styrene-butadiene rubber, the resistance of the elastic resin layer to various chemical solutions used in the plating process is improved, and the wiring board can be manufactured with high yield.

Commercially available acrylic rubbers include, for example, Nippon Zeon Co., Ltd. "Nipol AR Series" and Kuraray Co., Ltd. "Clarity Series."

Examples of commercial products of isoprene rubber include Nippon Zeon Co., Ltd. “Nipol IR Series”.

Examples of commercial products of butyl rubber include JSR Corporation "BUTYL Series".

Commercially available styrene-butadiene rubbers include, for example, JSR Corporation "DYNARON SEBS Series" and "DYNARON HSBR Series", Kraton Polymer Japan Co., Ltd. "Kraton D Polymer Series", and Aron Kasei Co., Ltd. "AR Series".

Examples of commercial products of butadiene rubber include Nippon Zeon Co., Ltd. "Nipol BR Series".

Examples of commercial products of acrylonitrile-butadiene rubber include JSR Corporation "JSR NBR Series".

Examples of commercial products of silicone rubber include Shin-Etsu Silicone Co., Ltd. "KMP Series".

Commercially available ethylene propylene rubbers include, for example, JSR Co., Ltd. "JSR EP Series".

Commercial products of fluororubber include, for example, Daikin Co., Ltd. "DAI-EL Series".

As a commercial product of epichlorohydrin rubber, Nippon Zeon Co., Ltd. "Hydrin series" is mentioned, for example.

(A) The rubber component can also be produced synthetically. For example, acrylic rubber can be obtained by reacting (meth)acrylic acid, (meth)acrylic acid ester, aromatic vinyl compound, vinyl cyanide compound, and the like.

(A) The rubber component may contain a rubber having a cross-linking group. The use of rubber having a cross-linking group tends to improve the heat resistance of the stretchable resin layer. The cross-linking group may be any reactive group capable of promoting the reaction of cross-linking the molecular chains of the (A) rubber component. Examples thereof include reactive groups, acid anhydride groups, amino groups, hydroxyl groups, epoxy groups and carboxyl groups possessed by the (B) cross-linking component described later.

(A) The rubber component may contain a rubber having at least one cross-linking group of an acid anhydride group or a carboxyl group. Examples of rubbers with anhydride groups include rubbers partially modified with maleic anhydride. Rubbers partially modified with maleic anhydride are polymers containing constitutional units derived from maleic anhydride. Commercially available rubbers partially modified with maleic anhydride include, for example, Asahi Kasei Corporation's styrenic elastomer "TUFPRENE 912".

The rubber partially modified with maleic anhydride may be a hydrogenated styrenic elastomer partially modified with maleic anhydride. Hydrogenated styrene-based elastomers are also expected to have effects such as improved weather resistance. A hydrogenated styrenic elastomer is an elastomer obtained by adding hydrogen to the unsaturated double bond of a styrenic elastomer having a soft segment containing an unsaturated double bond. Examples of commercially available hydrogenated styrene elastomers partially modified with maleic anhydride include "FG1901" and "FG1924" manufactured by Kraton Polymer Japan Co., Ltd., and "Tuftec M1911" and "Tuftec M1913" manufactured by Asahi Kasei Corporation. , and Tuftec M1943.

(A) The weight average molecular weight of the rubber component may be 20,000 to 200,000, 30,000 to 150,000, or 50,000 to 125,000 from the viewpoint of coating properties. A weight average molecular weight (Mw) here means a standard polystyrene conversion value calculated|required by a gel permeation chromatography (GPC).

In the resin composition, the content of (A) the rubber component is preferably 60 to 95% by mass based on the total amount of (A) the rubber component, (B) the cross-linking component and (C) the ester curing agent. , more preferably 65 to 90% by mass, even more preferably 70 to 85% by mass. (A) When the content of the rubber component is 60% by mass or more, more sufficient stretchability is likely to be obtained, and the rubber component and the cross-linking component tend to mix well. (A) When the content of the rubber component is 95% by mass or less, the elastic resin layer tends to have particularly excellent properties in terms of adhesion, insulation reliability, and heat resistance. The content of the (A) rubber component in the stretchable resin layer may be within the above range based on the mass of the stretchable resin layer.

(B) The cross-linking component having an epoxy group is a component that cross-links during the curing reaction to form a cross-linked polymer. (B) The cross-linking component having an epoxy group is not particularly limited as long as it has an epoxy group in its molecule, and can be, for example, a general epoxy resin. The epoxy resin may be monofunctional, bifunctional, or polyfunctional, and is not particularly limited, but bifunctional or polyfunctional epoxy resins may be used to obtain sufficient curability.

Examples of epoxy resins include bisphenol A type, bisphenol F type, phenol novolak type, naphthalene type, dicyclopentadiene type, cresol novolak type, and the like. Epoxy resins modified with fatty chains can impart flexibility. Commercially available fatty chain-modified epoxy resins include, for example, EXA-4816 manufactured by DIC Corporation. A phenol novolak type, cresol novolak type, naphthalene type, or dicyclopentadiene type epoxy resin may be selected from the viewpoint of curability, low tackiness, and heat resistance. These epoxy resins can be used alone or in combination of two or more.

The combination of a rubber having a maleic anhydride group or a carboxyl group and a compound having an epoxy group (epoxy resin) improves the heat resistance and low moisture permeability of the stretchable resin layer, the adhesion between the stretchable resin layer and the conductive layer, In addition, particularly excellent effects can be obtained in terms of low tackiness of the stretchable resin layer. When the heat resistance of the stretchable resin layer is improved, deterioration of the stretchable resin layer in a heating process such as nitrogen reflow can be suppressed. When the stretchable resin layer has low tack, it is possible to handle the conductive substrate or wiring substrate with good workability.

The resin composition may contain a cross-linking component other than (B) the cross-linking component having an epoxy group, as long as the effects of the present invention are not significantly impaired. From the viewpoint of sufficiently reducing the dielectric loss tangent of the elastic resin layer, the content of the other cross-linking component is preferably less than 10 parts by mass with respect to 100 parts by mass of the (B) cross-linking component having an epoxy group.

(C) The ester-based curing agent is a compound that itself participates in the curing reaction, and can reduce the dielectric loss tangent while improving the heat resistance of the stretchable resin layer.

The ester-based curing agent is not particularly limited, but from the viewpoint of sufficiently obtaining the effect of improving heat resistance and reducing the dielectric loss tangent, phenol esters, thiophenol esters, N-hydroxyamine esters, heterocyclic hydroxy compounds. A compound having one or two or more highly reactive ester groups in one molecule, such as esters of (1), is preferably used. More specific examples of the ester curing agent include "EPICLON HPC8000-65T", "EPICLON HPC8000-L-65MT", and "EPICLON HPC8150-60T" (all trade names manufactured by DIC Corporation). . These can be used individually by 1 type or in combination of 2 or more types.

It is believed that the ester-based curing agent reacts with the cross-linking component (B) as shown in formula (I) below during the curing reaction. In the reaction between (C) the ester-based curing agent and (B) the cross-linking component, hydroxyl groups are not generated, and even if a side reaction occurs, hydroxyl groups are unlikely to be generated. As a result, a low dielectric loss tangent is achieved. It is considered possible.

式中、Ｒ^１、Ｒ^２及びＲ^３はそれぞれ独立に、１価の有機基を示すが、本発明の効果がより十分に得られることから、芳香環を有する１価の有機基であってもよい。

In the formula, R ¹ , R ² and R ³ each independently represent a monovalent organic group. good too.

The resin composition may contain a curing agent other than (C) the ester-based curing agent as long as the effects of the present invention are not significantly impaired. From the viewpoint of sufficiently reducing the dielectric loss tangent of the elastic resin layer, the content of the other curing agent is preferably less than 10 parts by mass with respect to 100 parts by mass of the (C) ester-based curing agent.

In the resin composition, the total content of (B) the cross-linking component and (C) the ester-based curing agent is based on the total amount of (A) the rubber component, (B) the cross-linking component and (C) the ester-based curing agent, It is preferably 5 to 40% by mass, more preferably 10 to 35% by mass, even more preferably 15 to 30% by mass. When the total content of (B) the cross-linking component and (C) the ester-based curing agent is 5% by mass or more, more sufficient curing can be easily obtained, and the stretchable resin layer exhibits adhesion, insulation reliability, and It tends to have particularly excellent properties in terms of heat resistance. When the total content of (B) the cross-linking component and (C) the ester-based curing agent is 40% by mass or less, it is easy to obtain sufficient stretchability, and the rubber component and the cross-linking component tend to mix well. .

In the resin composition, the content ratio of (B) the cross-linking component and (C) the ester-based curing agent is the equivalent ratio of the epoxy groups in the (B) epoxy resin and the ester bonds in the (C) ester-based curing agent. and preferably in the range of 4:5 to 5:4. When the content ratio is within the above range, more sufficient curing is likely to be obtained, and the stretchable resin layer tends to have particularly excellent properties in terms of adhesion, insulation reliability, and heat resistance.

The resin composition may further contain (D) a curing accelerator. (D) A curing accelerator is a compound that functions as a catalyst for the curing reaction. (D) The curing accelerator may be selected from tertiary amines, imidazoles, organic acid metal salts, phosphorus compounds, Lewis acids, amine complex salts and phosphines. Among these, imidazole may be used from the viewpoint of storage stability and curability of the varnish of the resin composition. (A) When the rubber component contains rubber partially modified with maleic anhydride, an imidazole compatible with this may be selected.

In the resin composition, the content of the (D) curing accelerator is 0.1 to 10 parts per 100 parts by mass of the total amount of (A) the rubber component, (B) the cross-linking component and (C) the ester curing agent. It may be parts by mass. (D) When the content of the curing accelerator is 0.1 parts by mass or more, there is a tendency that more sufficient curing is likely to be obtained. (D) When the content of the curing accelerator is 10 parts by mass or less, there is a tendency that more sufficient heat resistance can be easily obtained. From the above point of view, the content of (D) curing accelerator may be 0.3 to 7 parts by mass, or 0.5 to 5 parts by mass.

In addition to the above components, the resin composition may optionally contain an antioxidant, an anti-yellowing agent, an ultraviolet absorber, a visible light absorber, a colorant, a plasticizer, a stabilizer, a filler, a flame retardant, and a leveling agent. Agents and the like may be further included within a range that does not significantly impair the effects of the present invention.

In particular, the resin composition may contain at least one deterioration inhibitor selected from the group consisting of antioxidants, heat stabilizers, light stabilizers, and hydrolysis inhibitors. Antioxidants suppress deterioration due to oxidation. Also, the antioxidant imparts sufficient heat resistance at high temperatures to the stretchable resin layer. The heat stabilizer imparts stability at high temperatures to the stretchable resin layer. Examples of light stabilizers include ultraviolet absorbers that prevent deterioration due to ultraviolet light, light blocking agents that block light, and quenching agents that receive light energy absorbed by organic materials and stabilize the organic materials. mentioned. The anti-hydrolysis agent suppresses deterioration due to moisture. The deterioration inhibitor may be at least one selected from the group consisting of antioxidants, heat stabilizers, and ultraviolet absorbers. As the anti-deterioration agent, one of the components exemplified above may be used alone, or two or more thereof may be used in combination. Two or more anti-deterioration agents may be used in combination to obtain better effects.

The antioxidant may be, for example, one or more selected from the group consisting of phenol antioxidants, amine antioxidants, sulfur antioxidants, and phosphite antioxidants. Two or more antioxidants may be used in combination in order to obtain better effects. A phenol-based antioxidant and a sulfur-based antioxidant may be used in combination.

The phenolic antioxidant may be a compound having a substituent having a large steric hindrance such as a t-butyl group (tertiary butyl group) and a trimethylsilyl group at the ortho position of the phenolic hydroxyl group. Phenolic antioxidants are also called hindered phenolic antioxidants.

Phenolic antioxidants include, for example, 2-t-butyl-4-methoxyphenol, 3-t-butyl-4-methoxyphenol, 2,6-di-t-butyl-4-ethylphenol, 2,2'- methylene-bis(4-methyl-6-t-butylphenol), 4,4'-thiobis-(3-methyl-6-t-butylphenol), 4,4'-butylidenebis(3-methyl-6-t-butylphenol ), 1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)butane, 1,3,5-trimethyl-2,4,6-tris(3,5-di-t -butyl-4-hydroxybenzyl)benzene and tetrakis-[methylene-3-(3′,5′-di-t-butyl-4′-hydroxyphenyl)propionate]methane. may be Phenolic antioxidants include 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene and tetrakis-[methylene-3-(3' , 5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane, a polymeric phenol antioxidant.

Phosphite-based antioxidants include, for example, triphenylphosphite, diphenylisodecylphosphite, phenyldiisodecylphosphite, 4,4′-butylidene-bis(3-methyl-6-t-butylphenylditridecyl)phosphite , cyclic neopentanetetrayl bis(nonylphenyl) phosphite, cyclic neopentanetetrayl bis(dinonylphenyl) phosphite, cyclic neopentanetetrayl tris(nonylphenyl)phosphite, cyclic neopentanetetrayl Tris(dinonylphenyl)phosphite, 10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide, 2,2-methylenebis(4,6-di-t- butylphenyl)-2-ethylhexylphosphite, diisodecylpentaerythritol diphosphite, and tris(2,4-di-t-butylphenyl)phosphite. It may be (2,4-di-t-butylphenyl)phosphite.

Examples of other antioxidants include hydroxylamine-based antioxidants typified by N-methyl-2-dimethylaminoacetohydroxamic acid, and sulfur-based antioxidants typified by dilauryl 3,3'-thiodipropionate. is mentioned.

The content of the antioxidant may be 0.1 to 20% by mass based on the mass (total solid content) of the resin composition. When the content of the antioxidant is 0.1% by mass or more, it is easy to obtain sufficient heat resistance of the stretchable resin layer. Bleeding and blooming can be suppressed when the content of the antioxidant is 20% by mass or less.

The molecular weight of the antioxidant may be 400 or more, 600 or more, or 750 or more from the viewpoint of preventing sublimation during heating. When two or more antioxidants are included, the average molecular weight thereof may be within the above range.

Thermal stabilizers (thermal deterioration inhibitors) include metal soaps or inorganic acid salts such as combinations of zinc salts and barium salts of higher fatty acids, organic tin compounds such as organic tin maleate and organic tin mercaptide, and fullerenes (e.g., fullerene hydroxide).

UV absorbers include, for example, benzophenone-based UV absorbers typified by 2,4-dihydroxybenzophenone, and benzotriazole-based UV absorbers typified by 2-(2′-hydroxy-5′-methylphenyl)benzotriazole. and cyanoacrylate-based UV absorbers typified by 2-ethylhexyl-2-cyano-3,3'-diphenylacrylate.

Hydrolysis inhibitors include, for example, carbodiimide derivatives, epoxy compounds, isocyanate compounds, acid anhydrides, oxazoline compounds, and melamine compounds.

Examples of other antidegradants include hindered amine light stabilizers, ascorbic acid, propyl gallate, catechins, oxalic acid, malonic acid, and phosphites.

The stretchable resin layer is obtained by dissolving or dispersing, for example, (A) a rubber component, (B) a cross-linking component, (C) an ester curing agent, and optionally other components in an organic solvent to obtain a resin varnish. and forming a resin varnish on a conductor foil or carrier film by a method described below.

The organic solvent used here is not particularly limited, but examples include aromatic hydrocarbons such as toluene, xylene, mesitylene, cumene and p-cymene; cyclic ethers such as tetrahydrofuran and 1,4-dioxane; acetone, methyl ethyl ketone; ketones such as methyl isobutyl ketone, cyclohexanone, 4-hydroxy-4-methyl-2-pentanone; esters such as methyl acetate, ethyl acetate, butyl acetate, methyl lactate, ethyl lactate, and γ-butyrolactone; ethylene carbonate, propylene carbonate, etc. carbonic acid ester; and amides such as N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, and the like. From the viewpoint of solubility and boiling point, toluene or N,N-dimethylacetamide may be used. These organic solvents can be used alone or in combination of two or more. The solid content (components other than the organic solvent) concentration in the resin varnish may be 20 to 80% by mass.

Examples of the carrier film include, but are not limited to, polyesters such as polyethylene terephthalate (PET), polybutylene terephthalate, and polyethylene naphthalate; polyolefins such as polyethylene and polypropylene; polycarbonates, polyamides, polyimides, polyamideimides, polyetherimides, poly Examples include films of ether sulfide, polyether sulfone, polyether ketone, polyphenylene ether, polyphenylene sulfide, polyarylate, polysulfone, and liquid crystal polymer. Among these, films of polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polypropylene, polycarbonate, polyamide, polyimide, polyamideimide, polyphenylene ether, polyphenylene sulfide, polyarylate, or polysulfone are used from the viewpoint of flexibility and toughness. It may be used as a carrier film.

The thickness of the carrier film is not particularly limited, but may be 3 to 250 μm. When the thickness of the carrier film is 3 μm or more, sufficient film strength is obtained, and when the thickness of the carrier film is 250 μm or less, sufficient flexibility can be obtained. From the above viewpoints, the thickness may be 5 to 200 μm, or 7 to 150 μm. From the viewpoint of improving releasability from the stretchable resin layer, a film obtained by subjecting the carrier film to release treatment with a silicone-based compound, a fluorine-containing compound, or the like may be used as necessary.

If necessary, a protective film may be attached onto the stretchable resin layer to form a laminated film having a three-layer structure consisting of a conductor foil or carrier film, a stretchable resin layer and a protective film.

The protective film is not particularly limited, and examples thereof include films of polyesters such as polyethylene terephthalate, polybutylene terephthalate and polyethylene naphthalate; and polyolefins such as polyethylene and polypropylene. Among them, polyester such as polyethylene terephthalate and polyolefin film such as polyethylene and polypropylene may be used as the protective film from the viewpoint of flexibility and toughness. From the viewpoint of improving releasability from the stretchable resin layer, the protective film may be subjected to release treatment with a silicone-based compound, a fluorine-containing compound, or the like.

The thickness of the protective film may be appropriately changed depending on the desired flexibility, and may be 10 to 250 μm. When the thickness is 10 μm or more, the film strength tends to be sufficient, and when the thickness is 250 μm or less, sufficient flexibility tends to be obtained. From the above viewpoints, the thickness may be 15 to 200 μm, or 20 to 150 μm.

[Method for manufacturing wiring board]
A wiring board having a conductor foil according to one embodiment includes, for example, a step of preparing a laminated plate (conductor substrate) having a stretchable resin layer and a conductor foil laminated on the stretchable resin layer; forming an etching resist; exposing the etching resist; developing the etching resist after exposure to form a resist pattern covering a portion of the conductor foil; It can be manufactured by a method including a step of removing the foil and a step of removing the resist pattern.

As a method for obtaining a laminate (conductor substrate) having a stretchable resin layer and a conductor foil, any method may be used. There is a method of coating, and a method of laminating a conductive foil on a stretchable resin layer formed on a carrier film by a vacuum press, a laminator, or the like. The stretchable resin layer can be formed by heating the resin composition to advance the cross-linking reaction (curing reaction) of the cross-linking component.

Any technique may be used for laminating the stretchable resin layer on the carrier film to the conductor foil, but a roll laminator, vacuum laminator, vacuum press, or the like may be used. From the viewpoint of production efficiency, a roll laminator or a vacuum laminator may be used for molding.

Although the thickness of the stretchable resin layer after drying is not particularly limited, it is usually 5 to 1000 μm. Within the above range, sufficient strength of the stretchable resin layer can be easily obtained, and sufficient drying can be performed, so that the amount of residual solvent in the stretchable resin layer can be reduced.

A laminate having conductor foils formed on both sides of the stretchable resin layer may be produced by further laminating conductor foil on the surface of the stretchable resin layer opposite to the conductor foil. By providing conductor layers on both sides of the stretchable resin layer, it is possible to suppress warping of the laminate during curing.

As a technique for forming a wiring pattern on a conductor foil of a laminated board (laminated board for forming a wiring board), a technique using etching or the like is generally used. For example, when a copper foil is used as the conductor foil, a mixed solution of concentrated sulfuric acid and hydrogen peroxide, a ferric chloride solution, or the like can be used as the etchant.

Examples of etching resists used for etching include Photech H-7025 (manufactured by Hitachi Chemical Co., Ltd., trade name), Photech H-7030 (manufactured by Hitachi Chemical Co., Ltd., trade name), X-87 (manufactured by Taiyo Holdings Co., Ltd., product name). The etching resist is usually removed after forming the wiring pattern.

One embodiment of a method for manufacturing a wiring board having a conductor plating film comprises the steps of: forming a conductor plating film on an elastic resin layer by electroless plating; forming a plating resist on the conductor plating film; A process of exposing the resist and developing the plating resist after exposure to form a resist pattern covering a part of the elastic resin layer, and electroplating on the conductor plating film of the part not covered by the resist pattern. Further forming a conductive plated film, removing the resist pattern, and removing a portion of the conductive plated film formed by electroless plating that is not covered by the conductive plated film formed by electrolytic plating. and including.

Yet another embodiment of the method for manufacturing a wiring board includes the steps of forming an etching resist on a conductive plating film formed on a stretchable resin layer, exposing the etching resist, and developing the etching resist after exposure. forming a resist pattern that partially covers the stretchable resin layer; removing the conductive plating film from the portion not covered by the resist pattern; and removing the resist pattern.

Examples of plating resists used as plating masks include Photech RY3325 (manufactured by Hitachi Chemical Co., Ltd., trade name), Photech RY-5319 (manufactured by Hitachi Chemical Co., Ltd., trade name), MA-830 (manufactured by Taiyo Holdings Co., Ltd., product name). Other details of electroless plating and electrolytic plating are as described above.

A stretchable device can be obtained by mounting various electronic elements on a wiring substrate.

The present invention will be described more specifically with reference to the following examples. However, the present invention is not limited to these examples.

(Example 1)
<Preparation of resin varnish for forming elastic resin layer>
(A) 80 parts by mass of maleic anhydride-modified styrene-ethylene-butadiene rubber (manufactured by KRATON Co., Ltd., trade name "FG1924GT") diluted with toluene and adjusted to a nonvolatile content of 25% by mass (amount of nonvolatile content); ) 11.1 parts by mass of a dicyclopentadiene type epoxy resin (manufactured by DIC Corporation, trade name “EPICLON HP7200H”) diluted with toluene and adjusted to a nonvolatile content of 25% by mass as a component (amount of nonvolatile content), (C) Ester-based curing agent (manufactured by DIC Corporation, trade name “HPC8000-65T”, dicyclopentadiene type diphenol compound) diluted with toluene and adjusted to 25% by mass of nonvolatile content as a component) 8.9 parts by mass (nonvolatile content compounding amount), and 3 parts by mass of 1-benzyl-2-methylimidazole (manufactured by Shikoku Kasei Co., Ltd., trade name “1B2MZ”) as component (D) were mixed with stirring to obtain a resin varnish.

<Production of laminated film>
A release-treated polyethylene terephthalate (PET) film (manufactured by Teijin DuPont Films Limited, trade name “Purex A31”, thickness 25 μm) was prepared as a carrier film. The resin varnish was applied onto the release-treated surface of the PET film using a knife coater (manufactured by Yasui Seiki Co., Ltd., product name: "SNC-350"). The coating film is dried by heating at 100° C. for 20 minutes in a dryer (manufactured by Futaba Kagaku Co., Ltd., trade name “MSO-80TPS”) to form a 100 μm-thick resin layer (elastic resin layer before curing). let me A release-treated PET film, which was the same as the carrier film, was attached as a protective film to the formed resin layer so that the release-treated surface faced the resin layer, thereby obtaining a laminated film.

<Production of conductor substrate>
An electrolytic copper foil having a roughened surface with a surface roughness Ra of 1.5 μm on the exposed resin layer after peeling the protective film of the laminated film (manufactured by Furukawa Electric Co., Ltd., trade name “F2-WS-12”) were stacked with the roughened surface facing the resin layer. In that state, using a vacuum pressurized laminator (manufactured by Nikko Materials Co., Ltd., trade name "V130"), the electrolytic copper foil was applied to the resin layer under the conditions of a pressure of 0.5 MPa, a temperature of 90 ° C., and a pressurization time of 60 seconds. laminated to. After that, by heating at 180 ° C. for 60 minutes in a dryer (manufactured by Futaba Kagaku Co., Ltd., product name "MSO-80TPS"), an elastic resin layer, which is a cured product of the resin layer, and an electrolytic copper foil as a conductor layer. A conductor substrate having

(Examples 2-6 and Comparative Examples 1-2)
A resin varnish, a laminated film and a conductor substrate were produced in the same manner as in Example 1 except that the composition of the resin varnish was changed to the composition shown in Table 1. In Table 1, "HP5000" is a novolac type epoxy resin (manufactured by DIC Corporation, trade name "EPICLON HP5000"), and "HPC8000-L-65MT" is an ester curing agent (manufactured by DIC Corporation, Product name "EPICLON HPC8000-L-65MT", low molecular weight grade of HPC8000-65T), "HPC8150-60T" is an ester curing agent (manufactured by DIC Corporation, product name "EPICLON HPC8150-60T", naphthalene skeleton is a compound having In addition, the blending amount of each component in Table 1 is the blending amount of the non-volatile matter, and the unit is "parts by mass".

[Measurement of tensile modulus and elongation at break]
The resin layers were cured by heating the laminated films obtained in Examples and Comparative Examples at 180° C. for 60 minutes to form elastic resin layers. After removing the carrier film and the protective film, the stretchable resin layer was cut into strips having a length of 40 mm and a width of 10 mm to obtain test pieces. A tensile test of this test piece was performed using an autograph (manufactured by Shimadzu Corporation, trade name "EZ-S") to obtain a stress-strain curve. The obtained stress-strain curve was used to determine the tensile modulus and elongation at break. The tensile test was performed under the conditions of a chuck-to-chuck distance of 20 mm and a tensile speed of 50 mm/min. The tensile modulus was obtained from the slope of the stress-strain curve in the stress range of 0.5 to 1.0N. The strain at which the specimen broke was recorded as the breaking elongation. Table 1 shows the results.

[Measurement of recovery rate]
A strip-shaped elastic resin layer test piece having a length of 40 mm and a width of 10 mm was prepared in the same manner as in the measurement of the tensile modulus and elongation at break. This test piece is elongated to a strain of 20% at a tensile speed of 100 mm / min using an autograph (manufactured by Shimadzu Corporation, trade name "EZ-S"), then the stress is released and returned to the initial position. Then, the tensile test was performed again. The recovery rate R is obtained by the following formula, where X is the strain (displacement amount) applied in the first tensile test, and Y is the difference between the position where the load starts to be applied when the tensile test is performed again and X. . In this test, X is 20%. Table 1 shows the results.
R (%) = Y/X x 100

[Measurement of dielectric constant (Dk) and dielectric loss tangent (Df)]
A test piece of the stretchable resin layer having a size of 80 mm×80 mm was prepared in the same manner as the measurement of the tensile modulus and elongation at break. Using this test piece, Dk and Df were calculated by the cavity resonator method. Vector type network analyzer E8364B (manufactured by Keysight Technologies), CP531 (manufactured by Kanto Denshi Applied Development Co., Ltd.) and CPMA-V2 (program) are used as measuring instruments, and measurements are performed under the conditions of an ambient temperature of 25°C and a frequency of 10 kHz. did Table 1 shows the results.

[Evaluation of heat resistance]
The laminated films obtained in Examples 1 to 6 and Comparative Examples 1 and 2 were heated at 180° C. for 60 minutes to cure the resin layer and form a stretchable resin layer. After removing the carrier film and protective film, the elastic resin layer is removed using a nitrogen reflow system (manufactured by Tamura Seisakusho Co., Ltd., trade name “TNV-EN”), a diagram conforming to IPC / JEDEC J-STD-020 A heat resistance test was conducted in which the process of heat treatment with the temperature profile of No. 3 was repeated 10 times. After the heat resistance test, the tensile modulus, elongation at break and recovery rate of the stretchable resin layer were measured in the same manner as above. The results are shown in Tables 2 and 3 together with the measurement results before the heat resistance test.

[Measurement of infrared absorption spectrum (IR)]
The resin layer (elastic resin layer before curing) of the laminated film of Comparative Example 1, the elastic resin layer after curing by heating it at 180 ° C. for 60 minutes, and the resins of the laminated films of Examples 1 and 3 After removing the carrier film and the protective film, the stretchable resin layer after curing by heating the layer at 180 ° C. for 60 minutes was measured with a Fourier transform infrared spectrophotometer (manufactured by Bio-Rad, trade name "FTS3000MX"). was used to measure the infrared absorption spectrum by the transmission method. FIG. 4 shows infrared absorption spectra of the elastic resin layer before and after curing of Comparative Example 1, and FIG. 5 shows infrared absorption spectra of the elastic resin layers after curing of Examples 1 and 3 and Comparative Example 1, respectively. .

As shown in FIG. 4, in the stretchable resin layer of Comparative Example 1, after curing, an absorption peak around 3400 ^cm attributed to the stretching vibration of hydroxyl groups, which was not present before curing, appeared. It was confirmed that hydroxyl groups were generated. Further, as shown in FIG. 5, in the elastic resin layers of Examples 1 and 3, there was almost no absorption peak attributed to the stretching vibration of hydroxyl groups, confirming that the generation of hydroxyl groups was suppressed.

[Production of Wiring Board and its Evaluation]
As shown in FIG. 2 , a test wiring board 1 having a conductive layer 5 made of an elastic resin layer 3 and a conductor foil (electrolytic copper foil) having a corrugated pattern formed on the elastic resin layer 3 was produced. . First, an etching resist (manufactured by Hitachi Chemical Co., Ltd., product name “Photech RY-5325”) was applied on the conductor layer of the conductor substrate obtained in Examples and Comparative Examples in which unevenness was formed on the surface of the elastic resin layer using a roll laminator. , and a phototool having a wavy pattern was brought into close contact therewith. The etching resist was exposed with an energy dose of 50 mJ/cm ² using an EXM-1201 type exposing machine manufactured by Oak Manufacturing Co., Ltd. Next, spray development was carried out with a 1% by mass sodium carbonate aqueous solution at 30° C. for 240 seconds to dissolve the unexposed portions of the etching resist, thereby forming a resist pattern having wavy openings. Then, an etchant was used to remove portions of the copper foil that were not covered with the resist pattern. After that, the etching resist is removed with a stripping solution, and the wiring substrate 1 having the conductor layer 5 on the stretchable resin layer 3 has a wavy wiring pattern with a wiring width of 50 μm and meandering along a predetermined direction X. got

The elastic resin layer and the wavy wiring pattern were observed when the obtained wiring board was tensile-deformed to a strain of 10% in the X direction and returned to its original state. As a result, neither the wiring board of the example nor the comparative example caused breakage of the elastic resin layer and the wiring pattern when stretched.

As is clear from the results shown in Table 1, the conductor substrates of Examples 1 to 6 have excellent stretchability and low dielectric loss tangent compared to the conductor substrates of Comparative Examples 1 and 2. confirmed. Moreover, as is clear from the results shown in Tables 2 and 3, it was confirmed that the conductive substrates of Examples 1 to 6 could maintain good stretchability and elastic modulus even after the heat resistance test.

The conductor substrate of the present invention and the wiring substrate obtained therefrom are expected to be applied, for example, as substrates for wearable devices.

DESCRIPTION OF SYMBOLS 1... Wiring board, 3... Stretchable resin layer, 5... Conductor layer (conductor foil or conductor plating film).

Claims (12)

an elastic resin layer;
A conductive substrate having a conductive plating film provided on the elastic resin layer,
The elastic resin layer comprises a cured product of a resin composition containing (A) a rubber component, (B) a cross-linking component having an epoxy group, and (C) an ester curing agent,
The content of the (A) rubber component in the resin composition is 60 to 95% by mass based on the total amount of the (A) rubber component, the (B) cross-linking component and the (C) ester curing agent. There is a conductive substrate. The rubber component (A) includes acrylic rubber, isoprene rubber, butyl rubber, styrene-butadiene rubber, butadiene rubber, acrylonitrile-butadiene rubber, silicone rubber, urethane rubber, chloroprene rubber, ethylene propylene rubber, fluororubber, vulcanized rubber, epichlorohydrin rubber, and 2. The conductor substrate according to claim 1, comprising at least one rubber selected from the group consisting of chlorinated butyl rubber. 3. The conductive substrate according to claim 1, wherein the (A) rubber component contains rubber having a cross-linking group. 4. The conductor substrate according to claim 3, wherein the cross-linking group is at least one of an acid anhydride group and a carboxyl group. The conductor substrate according to any one of claims 1 to 4, wherein the resin composition further contains (D) a curing accelerator. The conductor substrate according to any one of claims 1 to 5, wherein the resin composition further contains an antioxidant. A wiring substrate comprising the conductor substrate according to any one of claims 1 to 6, wherein the conductor plating film forms a wiring pattern. A stretchable device comprising the wiring board according to claim 7 and an electronic element mounted on the wiring board. Used for forming a wiring board including a conductive substrate having an elastic resin layer and a conductive plating film provided on the elastic resin layer, wherein the conductive plating film forms a wiring pattern , the conductive substrate according to any one of claims 1 to 6. A step of forming a plating resist on the elastic resin layer;
exposing the plating resist and developing the exposed plating resist to form a resist pattern covering a portion of the stretchable resin layer;
forming a conductive plating film by electroless plating on the surface of the stretchable resin layer not covered by the resist pattern;
and removing the resist pattern. a step of forming a conductive plating film on the stretchable resin layer by electroless plating;
forming a plating resist on the conductor plating film;
exposing the plating resist and developing the exposed plating resist to form a resist pattern covering a portion of the stretchable resin layer;
a step of further forming a conductor plating film by electroplating on the conductor plating film in a portion not covered with the resist pattern;
removing the resist pattern;
8. The method of manufacturing a wiring board according to claim 7, further comprising the step of removing a portion of the conductive plated film formed by electroless plating that is not covered by the conductive plated film formed by electrolytic plating. . forming an etching resist on the conductive plating film formed on the stretchable resin layer;
exposing the etching resist and developing the etching resist after exposure to form a resist pattern covering a portion of the stretchable resin layer;
a step of removing the conductor plating film in a portion not covered with the resist pattern;
removing the resist pattern;
8. The method of manufacturing a wiring board according to claim 7, comprising:

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