WO2019216425A1

WO2019216425A1 - Conductor substrate, wiring substrate, stretchable device, and method for manufacturing wiring substrate

Info

Publication number: WO2019216425A1
Application number: PCT/JP2019/018795
Authority: WO
Inventors: 禎宏小川; 剛史正木; 崇司川守; タンイーシム
Original assignee: 日立化成株式会社
Priority date: 2018-05-11
Filing date: 2019-05-10
Publication date: 2019-11-14
Also published as: JP2023029400A; TW201946777A; JP7338621B2; JP7468609B2; KR20210007956A; JPWO2019216425A1; JP7468611B2; JP7468610B2; JP2023029399A; JP2023029398A; CN112088089A

Abstract

Provided is a conductor substrate having a stretchable resin layer and a conductor foil provided on the stretchable resin layer, wherein 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.

Description

Conductor board, wiring board, stretchable device, and manufacturing method of wiring board

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 wiring substrate. Still another aspect of the present invention relates to a stretchable device using the wiring board.

In recent years, in the fields of wearable devices and healthcare-related devices, for example, there is a demand for flexibility and stretchability that can be used along the curved surface or joints of the body and hardly cause poor connection even when detached. In order to configure such a device, a wiring board or base material having high elasticity is required.

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

International Publication No. 2016/080346

As described in Patent Document 1, by providing the sealing material with elasticity, it became possible to realize a member having elasticity that was difficult with a conventional sealing material. On the other hand, since the base substrate does not have stretchability, it has been difficult to impart higher stretchability. Therefore, a wiring board having higher stretchability is required.

Also, from the viewpoint of improving heat resistance, it has been studied to use a crosslinking component having a reactive functional group as a material for producing a base substrate of a wiring board. However, when a cross-linking component having a reactive functional group is used, there is a problem that the dielectric loss tangent of the obtained base substrate tends to increase, and the transmission loss of the wiring provided on the base substrate tends to increase.

Under such circumstances, an 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 the wiring substrate. And

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

According to the conductor substrate, high elasticity can be obtained by using an elastic resin layer containing a rubber component (A) as the base substrate. In addition, 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 a hydroxyl group during the curing reaction. It is believed that there is. Since the hydroxyl group is a functional group having a small volume and a high polarizability, the material having the hydroxyl group has an increased dielectric loss tangent as a whole. In contrast, (B) a crosslinking component having an epoxy group as a crosslinking component and (C) an ester curing agent as a curing agent are used in combination to greatly suppress the formation of hydroxyl groups during the curing reaction of the crosslinking component. The inventors have found that this is possible. This is because the curing reaction between the epoxy group of the crosslinking component and the ester curing agent does not involve the generation of a hydroxyl group, and it is difficult to generate a hydroxyl group even after curing. Furthermore, these hardened | cured materials do not have a bad influence on stretchability. For this reason, according to the conductor substrate having the above configuration, it is possible to realize a low dielectric loss tangent while using a crosslinking component capable of improving heat resistance while maintaining high stretchability.

Another aspect of the present invention provides a wiring board including the conductor board of the present invention, wherein the conductor foil or the conductor plating film forms a wiring pattern. The wiring board has a high stretchability because the conductor foil or the conductor plating film in the conductor substrate of the present invention has a wiring pattern and is provided with a stretchable resin layer having the specific configuration. At the same time, by using a crosslinking component, it is possible to have a low dielectric loss tangent while having high heat resistance, and the transmission loss of the wiring pattern is sufficiently reduced.

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. Therefore, the stretchable device has high stretchability and high heat resistance by using a crosslinking component. Therefore, the transmission loss of the wiring pattern can be sufficiently reduced.

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

Another aspect of the present invention is a step of preparing a laminate having a stretchable resin layer and a conductive foil laminated on the stretchable resin layer, a step of forming an etching resist on the conductive foil, Exposing the etching resist, developing the exposed etching resist to form a resist pattern covering a part of the conductor foil, and removing the conductor foil in a portion not covered by the resist pattern There is provided a method for producing the wiring board of the present invention, comprising a step and a step of removing the resist pattern.

Another aspect of the present invention includes a step of forming a plating resist on the stretchable resin layer, exposing the plating resist, developing the exposed plating resist, and removing a part of the stretchable resin layer. A step of forming a resist pattern to cover, a step of forming a conductive plating film by electroless plating on a surface of a portion of the stretchable resin layer not covered by the resist pattern, a step of removing the resist pattern, A method for manufacturing the wiring board of the present invention is provided.

Another aspect of the present invention includes a step of forming a conductive plating film on the stretchable resin layer by electroless plating, a step of forming a plating resist on the conductive plating film, exposing the plating resist, and exposing The step of developing the plating resist later to form a resist pattern that covers a part of the stretchable resin layer, and conductor plating by electrolytic plating on the portion of the conductor plating film that is not covered by the resist pattern A step of further forming a film, a step of removing the resist pattern, and a step of removing a portion of the conductive plating film formed by electroless plating that is not covered by the conductive plating film formed by electrolytic plating And a method of manufacturing the wiring board of the present invention.

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

The wiring board of the present invention in which the conductive foil or the conductive plating film forms a wiring pattern can be efficiently manufactured by the above manufacturing method.

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

6 is a stress-strain curve showing an example of measurement of recovery rate. 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. It is a figure which shows the infrared absorption spectrum of the stretchable resin layer before and behind hardening of the comparative example 1. It is a figure which shows the infrared absorption spectrum of the stretchable resin layer after Example 1, 3 and the comparative example 1 after hardening.

Hereinafter, some embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments.

The conductive substrate according to one embodiment includes a stretchable resin layer and a conductor layer provided on one or both sides of the stretchable resin layer, and the stretchable resin layer comprises (A) a rubber component, ( B) The hardened | cured material of the resin composition containing the crosslinking component which has an epoxy group, and (C) ester type hardening | curing agent is included. A wiring board according to an embodiment has a stretchable resin layer containing a cured product of the resin composition, and a conductor layer provided on one 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 substrate>
[Conductor foil]
The elastic modulus of the conductor foil may be 40 to 300 GPa. When the elastic modulus of the conductor foil is 40 to 300 GPa, the conductor foil tends not to break due to the elongation of the wiring board. From the same viewpoint, the elastic modulus of the conductor foil may be 50 GPa or more, 60 GPa or more, or 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. As metal foil, 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, white 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 a copper foil, a gold foil, a nickel foil, and an iron foil from the viewpoint of an appropriate elastic modulus and the like. From the viewpoint of wiring formability, the conductor foil may be a copper foil. The copper foil can easily form a wiring pattern by photolithography without impairing the properties of the stretchable resin layer.

There is no restriction | limiting in particular as copper foil, For example, the electrolytic copper foil and rolled copper foil used for a copper clad laminated board, a flexible wiring board, etc. can be used. Examples of commercially available electrolytic copper foil include F0-WS-18 (Furukawa Electric Co., Ltd., trade name), NC-WS-20 (Furukawa Electric Co., Ltd., trade name), YGP-12 (Nippon Electrolytic Co., Ltd.) And FTS-WS-12 (trade name, manufactured by Furukawa Electric Co., Ltd.) and GTS-18 (trade name) manufactured by Furukawa Electric Co., Ltd. Examples of the rolled copper foil 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. (Mitsui Sumitomo Metal Mining Shindoh Co., Ltd., trade name). From the viewpoint of adhesion to the stretchable resin layer, a copper foil that has been subjected to 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 a roughening treatment. In this case, the metal foil is usually provided on the stretchable resin layer so that the roughened surface is in contact with the stretchable resin layer. From the viewpoint of adhesion between the stretchable resin layer and the metal foil, the surface roughness Ra of the roughened surface may be 0.1 to 3 μm, or 0.2 to 2.0 μm. In order to easily form fine wiring, the surface roughness Ra of the roughened surface may be 0.3 to 1.5 μm.

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

The thickness of the conductor foil is not particularly limited, but may be 1 to 50 μm. When the thickness of the conductor foil is 1 μm or more, the wiring pattern can be more easily formed. 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 stretchable resin layer. By providing the conductive foil on both surfaces of the stretchable resin layer, it is possible to suppress warping due to heating for curing or the like.

The method for providing the conductor foil is not particularly limited. For example, a method for directly applying a resin composition for forming a stretchable resin layer to a metal foil and a resin composition for forming a stretchable resin layer are provided. There is a method in which a resin layer (an elastic resin layer before curing) is formed by coating on a carrier film, and the formed resin layer is laminated on a conductor foil.

[Conductor plating film]
The conductor plating film can be formed by a normal plating method used for the additive method or the semi-additive method. For example, after applying a plating catalyst for depositing palladium, the stretchable resin layer is immersed in an electroless plating solution, and an electroless plating layer (conductor layer) having a thickness of 0.3 to 1.5 μm is formed on the entire surface of the primer. To precipitate. If necessary, electrolytic plating (electroplating) can be further performed to adjust to a necessary thickness. As an electroless plating solution used for electroless plating, any electroless plating solution can be used, and there is no particular limitation. An ordinary method can be employed for electrolytic plating, and there is no particular limitation. The conductor plating film (electroless plating film, electrolytic plating film) may be a copper plating film from the viewpoint of cost and resistance.

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

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

As a method for transferring the roughened surface of the copper foil, 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 (an elastic resin layer before curing) is molded on a copper foil after coating the resin composition on a carrier film. By forming a conductive plating film on both surfaces of the stretchable resin layer, warping due to heating for curing or the like can be suppressed.

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 used in a general wiring board manufacturing process.

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

[Elastic resin layer]
The stretchable resin layer can have stretchability such that the recovery rate after tensile deformation to 20% strain is 80% or more. This recovery rate is calculated | required in the tension test using the measurement sample of an elastic resin layer. The strain (displacement amount) applied in the first tensile test is X, and then the difference between X and the position at which the load starts when the tensile test is performed again after returning to the initial position is defined as Y: %) = R calculated by (Y / X) × 100 is defined as the recovery rate. The recovery rate can be measured with X as 20%. FIG. 1 is a stress-strain curve showing an example of measuring the recovery rate. From the viewpoint of resistance to repeated use, the recovery rate may be 80% or more, 85% or more, or 90% or more. The upper limit on the definition of the recovery rate is 100%.

The elastic modulus (tensile elastic modulus) of the stretchable 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 as a substrate tend to be particularly excellent. From this viewpoint, the elastic modulus may be 0.3 MPa to 100 MPa, or 0.5 MPa to 50 MPa.

The elongation at break of the stretchable resin layer may be 100% or more. When the elongation at break is 100% or more, sufficient stretchability tends to be obtained. From this viewpoint, the elongation at break may be 150% or more, 200% or more, 300% or more, or 500% or more. The upper limit of the elongation at break is not particularly limited, but is usually about 1000% or less.

The dielectric loss tangent (Df) of the stretchable 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 stretchable resin layer can be sufficiently reduced. From this viewpoint, the dielectric loss tangent may be 0.0035 or less, 0.003 or less, or 0.0025 or less. The lower limit of the dielectric loss tangent is not particularly limited, but is usually about 0.0005 or more.

The relative dielectric constant (Dk) of the stretchable resin layer may be 4.0 or less. When the relative 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 viewpoint, the relative 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 the hydroxyl group in its infrared absorption spectrum. Thereby, the dielectric loss tangent of the stretchable resin layer is sufficiently reduced, and the transmission loss of the wiring pattern provided on the stretchable resin layer tends to be sufficiently reduced.

The stretchable resin layer comprises a cured product of a resin composition (curable resin composition) containing (A) a rubber component, (B) a crosslinking component having an epoxy group, and (C) an ester-based curing agent. Including. That is, the stretchable 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 (A) rubber component.

(A) Rubber components include, 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, fluorine rubber, sulfurized rubber, epichlorohydrin rubber, And at least one rubber selected from the group consisting of chlorinated butyl rubbers. From the viewpoint of protecting damage to the wiring due to moisture absorption or the like, a rubber component having low gas permeability may be used. From such a viewpoint, 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 stretchable resin layer to various chemicals used in the plating process is improved, and a wiring board can be manufactured with high yield.

Examples of commercially available acrylic rubber include ZEON Corporation “Nipol AR Series” and Kuraray Co., Ltd. “Clarity Series”.

Examples of commercially available products of isoprene rubber include ZEON Corporation “Nipol IR Series”.

Examples of commercially available butyl rubber include JSR Corporation “BUTYL Series”.

Examples of commercially available styrene butadiene rubber include JSR Corporation “Dynalon SEBS Series”, “Dynaron HSBR Series”, Kraton Polymer Japan Co., Ltd. “Clayton D Polymer Series”, and Aron Kasei Corporation “AR Series”.

Examples of commercially available butadiene rubber include ZEON CORPORATION "Nipol BR series".

Examples of commercially available acrylonitrile butadiene rubber include JSR Corporation “JSR NBR Series”.

Examples of commercially available silicone rubber include Shin-Etsu Silicone Co., Ltd. “KMP Series”.

Examples of commercially available ethylene propylene rubber include JSR Corporation “JSR EP Series”.

Examples of commercially available fluororubber include Daikin Corporation “DAIEL Series”.

Examples of commercially available epichlorohydrin rubber include “Hydrin series” of ZEON CORPORATION.

(A) The rubber component can also be produced by synthesis. 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 rubber having a crosslinking group. By using the rubber having a crosslinking group, the heat resistance of the stretchable resin layer tends to be improved. The crosslinking group may be any reactive group that can cause the reaction of crosslinking the molecular chain of the rubber component (A). Examples thereof include a reactive group, an acid anhydride group, an amino group, a hydroxyl group, an epoxy group, and a carboxyl group that the (B) crosslinking component described later has.

(A) The rubber component may contain a rubber having at least one crosslinking group out of an acid anhydride group or a carboxyl group. Examples of rubbers having acid anhydride groups include rubbers that are partially modified with maleic anhydride. Rubber partially modified with maleic anhydride is a polymer containing structural units derived from maleic anhydride. As a commercial product of rubber partially modified with maleic anhydride, for example, there is a styrene elastomer “Tuffprene 912” manufactured by Asahi Kasei Corporation.

The rubber partially modified with maleic anhydride may be a hydrogenated styrene elastomer partially modified with maleic anhydride. The hydrogenated styrene-based elastomer can be expected to have an effect of improving weather resistance. A hydrogenated styrene-based elastomer is an elastomer obtained by adding hydrogen to an unsaturated double bond of a styrene-based elastomer having a soft segment including an unsaturated double bond. Examples of commercially available hydrogenated styrenic elastomers partially modified with maleic anhydride include “FG1901” and “FG1924” from Kraton Polymer Japan Co., Ltd., “Tuftec M1911” and “Tuftec M1913” from 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. The weight average molecular weight (Mw) here means a standard polystyrene conversion value determined by gel permeation chromatography (GPC).

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

(B) The crosslinking component having an epoxy group is a component that is crosslinked during the curing reaction to form a crosslinked polymer. (B) If the crosslinking component which has an epoxy group has an epoxy group in a molecule | numerator, it will not restrict | limit, For example, it can be a general epoxy resin. The epoxy resin may be monofunctional, bifunctional or polyfunctional, and is not particularly limited, but a bifunctional or polyfunctional epoxy resin may be used in order to obtain sufficient curability.

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

By combining a rubber having a maleic anhydride group or a carboxyl group and a compound having an epoxy group (epoxy resin), heat resistance and low moisture permeability of the stretchable resin layer, adhesion between the stretchable resin layer and the conductive layer, In addition, a particularly excellent effect is obtained in terms of low tack 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 a low tack, the conductor substrate or the wiring substrate can be handled with good workability.

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

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

Although it does not restrict | limit especially as ester type hardening | curing agent, From a viewpoint of obtaining more fully the heat resistant improvement effect and the dielectric loss tangent reduction effect, phenol ester, thiophenol ester, N-hydroxyamine ester, heterocyclic hydroxy compound A compound having one or two or more ester groups having a high reaction activity in one molecule, such as these esters, is preferably used. More specifically, examples of the ester-based curing agent include “EPICLON HPC8000-65T”, “EPICLON HPC8000-L-65MT”, “EPICLON HPC8150-60T” (all trade names made by DIC Corporation), and the like. . These can be used individually by 1 type or in combination of 2 or more types.

The ester-based curing agent is considered to react with the crosslinking component (B) as shown in the following formula (I) during the curing reaction. In such a reaction between the ester curing agent (C) and the crosslinking component (B), a hydroxyl group is not generated, and even if a side reaction occurs, it is difficult to generate a hydroxyl group, resulting in a low dielectric loss tangent. It is considered possible.

In the formula, R ¹ , R ² and R ³ each independently represent a monovalent organic group, but since the effects of the present invention can be obtained more sufficiently, the monovalent organic group having an aromatic ring is Also good.

The resin composition may contain (C) a curing agent other than the ester curing agent as long as the effects of the present invention are not significantly impaired. 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, from the viewpoint of sufficiently reducing the dielectric loss tangent of the stretchable resin layer.

In the resin composition, the total content of (B) crosslinking component and (C) ester curing agent is based on the total amount of (A) rubber component, (B) crosslinking component and (C) ester curing agent. It is preferably 5 to 40% by mass, more preferably 10 to 35% by mass, and further preferably 15 to 30% by mass. When the total content of the (B) crosslinking component and the (C) ester-based curing agent is 5% by mass or more, more sufficient curing is easily obtained, and the stretchable resin layer has adhesiveness, insulation reliability, and There is a tendency to have particularly excellent characteristics in terms of heat resistance. When the total content of the (B) crosslinking component and the (C) ester-based curing agent is 40% by mass or less, more sufficient stretchability is easily obtained, and the rubber component and the crosslinking component tend to mix well. .

In the resin composition, the content ratio of (B) crosslinking component to (C) ester curing agent is equivalent ratio of epoxy group in (B) epoxy resin and ester bond in (C) ester curing agent. And preferably in the range of 4: 5 to 5: 4. When the content ratio is in the above range, more sufficient curing is easily obtained, and the stretchable resin layer tends to have particularly excellent characteristics in terms of adhesion, insulation reliability, and heat resistance.

The resin composition may further contain (D) a curing accelerator. (D) The 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 a rubber partially modified with maleic anhydride, an imidazole compatible with the rubber may be selected.

In the resin composition, the content of the (D) curing accelerator is 0.1 to 10 with respect to 100 parts by mass of the total amount of (A) the rubber component, (B) the crosslinking component, and (C) the ester curing agent. A mass part may be sufficient. (D) When content of a hardening accelerator is 0.1 mass part or more, there exists a tendency for more sufficient hardening to be easy to be obtained. (D) When content of a hardening accelerator is 10 mass parts or less, there exists a tendency for more sufficient heat resistance to be acquired easily. From the above viewpoint, the content of the (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 contain antioxidants, yellowing inhibitors, UV absorbers, visible light absorbers, colorants, plasticizers, stabilizers, fillers, flame retardants, and leveling as necessary. You may further contain an agent etc. in the range which does not impair the effect of this invention remarkably.

In particular, the resin composition may contain at least one degradation inhibitor selected from the group consisting of an antioxidant, a heat stabilizer, a light stabilizer, and a hydrolysis inhibitor. Antioxidants suppress deterioration due to oxidation. Further, 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 rays, light blockers that block light, and quenchers that have a quenching function that receives light energy absorbed by organic materials and stabilizes organic materials. Can be mentioned. The hydrolysis inhibitor suppresses deterioration due to moisture. The deterioration inhibitor may be at least one selected from the group consisting of an antioxidant, a heat stabilizer, and an ultraviolet absorber. As a deterioration preventing agent, only 1 type may be used from the component illustrated above, and 2 or more types may be used together. In order to obtain a more excellent effect, two or more kinds of deterioration inhibitors may be used in combination.

The antioxidant may be, for example, one or more selected from the group consisting of a phenol-based antioxidant, an amine-based antioxidant, a sulfur-based antioxidant, and a phosphite-based antioxidant. In order to obtain a more excellent effect, two or more kinds of antioxidants may be used in combination. You may use together a phenolic antioxidant and sulfur type antioxidant.

The phenolic antioxidant may be a compound having a sterically hindered substituent such as a t-butyl group (tertiary butyl group) and a trimethylsilyl group at the ortho position of the phenolic hydroxyl group. The phenolic antioxidant is also referred to as a hindered phenolic antioxidant.

Examples of the phenolic antioxidant include 2-t-butyl-4-methoxyphenol, 3-t-butyl-4-methoxyphenol, 2,6-di-t-butyl-4-ethylphenol, and 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-tert-butylphenyl) butane, 1,3,5-trimethyl-2,4,6-tris (3,5-di-t) Selected from the group consisting of -butyl-4-hydroxybenzyl) benzene and tetrakis- [methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate] methane It may be a species or more compounds. Phenol 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] may be a polymer type phenolic antioxidant represented by methane.

Phosphite antioxidants include, for example, triphenyl phosphite, diphenylisodecyl phosphite, phenyl diisodecyl phosphite, 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- Butylpheny ) -2-ethylhexyl phosphite, diisodecylpentaerythritol diphosphite and tris (2,4-di-t-butylphenyl) phosphite may be used. , 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 of the resin composition (total solid content). When the content of the antioxidant is 0.1% by mass or more, sufficient heat resistance of the stretchable resin layer is easily obtained. When the content of the antioxidant is 20% by mass or less, bleeding and bloom can be suppressed.

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 kinds of antioxidants are contained, the average of their molecular weights may be in the above range.

Thermal stabilizers (heat degradation inhibitors) include metal soaps or inorganic acid salts such as combinations of higher fatty acid zinc and barium salts, organotin compounds such as organotin maleates and organotin mercaptides, and fullerenes (eg, Fullerene hydroxide).

Examples of the ultraviolet absorber include benzophenone ultraviolet absorbers represented by 2,4-dihydroxybenzophenone, and benzotriazole ultraviolet absorbers represented by 2- (2′-hydroxy-5′-methylphenyl) benzotriazole. And cyanoacrylate-based ultraviolet absorbers typified by 2-ethylhexyl-2-cyano-3,3′-diphenylacrylate.

Examples of the hydrolysis inhibitor include carbodiimide derivatives, epoxy compounds, isocyanate compounds, acid anhydrides, oxazoline compounds, and melamine compounds.

Examples of other deterioration inhibitors include hindered amine light stabilizers, ascorbic acid, propyl gallate, catechin, oxalic acid, malonic acid, and phosphite.

The stretchable resin layer is obtained, for example, by dissolving or dispersing (A) a rubber component, (B) a crosslinking component, (C) an ester-based curing agent, and, if necessary, other components in an organic solvent to obtain a resin varnish. And a method of forming a resin varnish on a conductive foil or a carrier film by a method described later.

The organic solvent used here is not particularly limited, and examples thereof 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, γ-butyrolactone; ethylene carbonate, propylene carbonate, etc. Carbonic acid esters; 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 concentration of solids (components other than organic solvent) in the resin varnish may be 20 to 80% by mass.

Although it does not restrict | limit especially as a carrier film, For example, Polyesters, such as polyethylene terephthalate (PET), polybutylene terephthalate, and polyethylene naphthalate; Polyolefins, such as polyethylene and a polypropylene; Polycarbonate, polyamide, a polyimide, polyamideimide, polyetherimide, poly Examples of the film include ether sulfide, polyether sulfone, polyether ketone, polyphenylene ether, polyphenylene sulfide, polyarylate, polysulfone, and liquid crystal polymer. Among these, from the viewpoint of flexibility and toughness, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polypropylene, polycarbonate, polyamide, polyimide, polyamideimide, polyphenylene ether, polyphenylene sulfide, polyarylate, or polysulfone film are used. 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, the film strength is sufficient, and when the thickness of the carrier film is 250 μm or less, sufficient flexibility is obtained. From the above viewpoint, the thickness may be 5 to 200 μm, or 7 to 150 μm. From the viewpoint of improving the peelability from the stretchable resin layer, a film obtained by subjecting the carrier film to a release treatment with a silicone compound, a fluorine-containing compound or the like may be used as necessary.

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

There is no restriction | limiting in particular as a protective film, For example, films, such as polyester, such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; Polyolefin, such as polyethylene and a polypropylene, are mentioned. Among these, from the viewpoint of flexibility and toughness, a film of polyester such as polyethylene terephthalate, or a polyolefin film such as polyethylene or polypropylene may be used as a protective film. From the viewpoint of improving the peelability from the stretchable resin layer, the protective film may be subjected to a release treatment with a silicone compound, a fluorine-containing compound, or the like.

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

[Method of manufacturing a wiring board]
A wiring board having a conductive foil according to an embodiment includes, for example, a step of preparing a laminated board (conductive board) having a stretchable resin layer and a conductive foil laminated on the stretchable resin layer; Forming an etching resist; exposing the etching resist; developing the exposed etching resist to form a resist pattern covering a portion of the conductor foil; and a portion of the conductor not covered by the resist pattern 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 (conductive substrate) having a stretchable resin layer and a conductor foil, any method may be used, but a varnish of a resin composition for forming a stretchable resin layer is used as a conductor foil. There are a method of coating, 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 crosslinking reaction (curing reaction) of the crosslinking component.

Any method may be used for laminating the stretchable resin layer on the carrier film on the conductor foil, but a roll laminator, a vacuum laminator, a vacuum press, or the like is used. You may shape | mold using a roll laminator or a vacuum laminator from a viewpoint of production efficiency.

The thickness of the stretchable resin layer after drying is not particularly limited, but is usually 5 to 1000 μm. Within the above range, sufficient strength of the stretchable resin layer can be easily obtained and drying can be performed sufficiently, 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 a conductor foil on the surface of the stretchable resin layer opposite to the conductor foil. By providing a conductor layer on both surfaces of the stretchable resin layer, it is possible to suppress warping of the laminated board during curing.

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

Etching resists used for etching include, for example, Photec H-7005 (trade name, manufactured by Hitachi Chemical Co., Ltd.), Fotec H-7030 (trade name, manufactured by Hitachi Chemical Co., Ltd.), X-87 (manufactured by Taiyo Holdings Co., Ltd., Product name). The etching resist is usually removed after the wiring pattern is formed.

One embodiment of a method of manufacturing a wiring board having a conductor plating film includes a step of forming a conductor plating film on the stretchable resin layer by electroless plating, a step of forming a plating resist on the conductor plating film, and plating. Exposing the resist, developing the exposed plating resist, forming a resist pattern that covers a part of the stretchable resin layer, and electrolytic plating on a portion of the conductor plating film not covered with the resist pattern A step of further forming a conductive plating film, a step of removing the resist pattern, and a step of removing a portion of the conductive plating film formed by electroless plating that is not covered by the conductive plating film formed by electrolytic plating And including.

Yet another embodiment of a method for manufacturing a wiring board includes a step of forming an etching resist on a conductive plating film formed on a stretchable resin layer, exposing the etching resist, and developing the exposed etching resist And the process of forming the resist pattern which covers a part of elastic resin layer, the process of removing the conductor plating film of the part which is not covered with the resist pattern, and the process of removing a resist pattern are included.

Examples of plating resists used as plating masks include FOTEC RY3325 (trade name, manufactured by Hitachi Chemical Co., Ltd.), FOTEC RY-5319 (trade name, manufactured by Hitachi Chemical Co., Ltd.), MA-830 (manufactured by Taiyo Holdings Co., Ltd., Product name). In addition, the 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 board.

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 (trade name “FG1924GT” manufactured by KRATON Co., Ltd.) diluted with toluene and adjusted to have a nonvolatile content of 25% by mass as component (B) ) Dicyclopentadiene type epoxy resin diluted with toluene as a component and adjusted to a nonvolatile content of 25% by mass (manufactured by DIC Corporation, trade name “EPICLON HP7200H”) 11.1 parts by mass (mixed amount of nonvolatile component), (C) 8.9 parts by mass (non-volatile content) of an ester-based curing agent (manufactured by DIC Corporation, trade name “HPC8000-65T”, dicyclopentadiene type diphenol compound) diluted with toluene as a component and adjusted to a non-volatile content of 25% by mass 1) -Benzyl-2-methylimidazole (Shikoku Kasei Co., Ltd.) as component (D) Product, product name “1B2MZ”) 3 parts by mass 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, trade name “Purex A31”, thickness 25 μm) was prepared as a carrier film. The resin varnish was applied onto the release-treated surface of this PET film using a knife coater (trade name “SNC-350” manufactured by Yasui Seiki Co., Ltd.). The coating film is dried by heating at 100 ° C. for 20 minutes in a dryer (trade name “MSO-80TPS” manufactured by Futaba Kagaku Co., Ltd.) to form a resin layer (stretchable resin layer before curing) having a thickness of 100 μm. I let you. On the formed resin layer, the same release treatment PET film as the carrier film was attached as a protective film with the release treatment surface facing the resin layer side to obtain a laminated film.

<Preparation of conductor substrate>
The protective film of the laminated film is peeled off and the exposed resin layer has a roughened surface with a surface roughness Ra of 1.5 μm (Furukawa Electric Co., Ltd., trade name “F2-WS-12”) Were stacked in such a direction that the roughened surface was on the resin layer side. In that state, 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 using a vacuum pressure laminator (trade name “V130” manufactured by Nikko Materials Co., Ltd.). Laminated. After that, by heating for 60 minutes at 180 ° C. in a dryer (trade name “MSO-80TPS” manufactured by Futaba Kagaku Co., Ltd.), an elastic resin layer, which is a cured product of the resin layer, and an electrolytic copper foil as a conductor layer A conductive 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 epoxy resin (manufactured by DIC Corporation, trade name “EPICLON HP5000”), and “HPC8000-L-65MT” is an ester-based curing agent (manufactured by DIC Corporation, Trade names “EPICLON HPC8000-L-65MT” and HPC8000-65T are low molecular weight grades. Compound). Moreover, the compounding quantity of each component in Table 1 is a compounding quantity of a non-volatile content, and a unit is a "mass part".

[Measurement of tensile modulus and elongation at break]
The laminated films obtained in Examples and Comparative Examples were heated at 180 ° C. for 60 minutes to cure the resin layer, thereby forming a stretchable resin layer. The carrier film and the protective film were removed, and 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 the test piece was performed using an autograph (trade name “EZ-S” manufactured by Shimadzu Corporation) to obtain a stress-strain curve. From the obtained stress-strain curve, the tensile modulus and elongation at break were determined. The tensile test was performed under the conditions of a distance between chucks of 20 mm and a tensile speed of 50 mm / min. The tensile elastic modulus was obtained from the slope of the stress-strain curve in the range of 0.5 to 1.0 N stress. The strain at the time when the test piece broke was recorded as the elongation at break. The results are shown in Table 1.

[Measurement of recovery rate]
In the same manner as the measurement of the tensile modulus and elongation at break, a strip-shaped test piece of a stretchable resin layer having a length of 40 mm and a width of 10 mm was produced. Using this autograph (manufactured by Shimadzu Corporation, trade name “EZ-S”), the specimen was stretched to a strain of 20% at a tensile speed of 100 mm / min, and then the stress was released and returned to the initial position. Then, the tensile test was performed again. The recovery rate R was obtained by the following equation, 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 when the tensile test is performed again and X. . In this test, X is 20%. The results are shown in Table 1.
R (%) = Y / X × 100

[Measurement of relative dielectric constant (Dk) and dielectric loss tangent (Df)]
A test piece of a stretchable resin layer having a size of 80 mm × 80 mm was produced 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. Measurement was performed using a vector network analyzer E8364B (manufactured by Keysight Technology), CP531 (manufactured by Kanto Electronics Application Development Co., Ltd.), and CPMA-V2 (program), respectively, at an ambient temperature of 25 ° C. and a frequency of 10 kHz. Went. The results are shown in Table 1.

[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, thereby forming a stretchable resin layer. After removing the carrier film and protective film, the stretchable resin layer is compliant with IPC / JEDEC J-STD-020 using a nitrogen reflow system (trade name “TNV-EN” manufactured by Tamura Seisakusho Co., Ltd.). A heat resistance test was performed by repeating the heat treatment process with the temperature profile of 3 ten times. After the heat resistance test, the tensile elastic modulus, elongation at break and recovery rate of the stretchable resin layer were measured by the same method as described 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)]
Resin layer (stretchable resin layer before curing) of the laminated film of Comparative Example 1, the stretchable resin layer after curing it by heating at 180 ° C. for 60 minutes, and the laminated film resins of Examples 1 and 3 For the stretchable resin layer after the layer was cured by heating at 180 ° C. for 60 minutes, the carrier film and the protective film were removed, and then a Fourier transform infrared spectrophotometer (trade name “FTS3000MX” manufactured by Bio-Rad) was used. Was used to measure an infrared absorption spectrum by a transmission method. FIG. 4 shows the infrared absorption spectrum of the stretchable resin layer before and after curing in Comparative Example 1, and FIG. 5 shows the infrared absorption spectrum of the stretchable resin layer after curing in 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 near 3400 cm ⁻¹ attributed to the stretching vibration of the hydroxyl group that did not exist before curing appeared. It was confirmed that a hydroxyl group was formed. Further, as shown in FIG. 5, it was confirmed that the stretchable resin layers of Examples 1 and 3 had almost no absorption peak attributed to the stretching vibration of the hydroxyl group, and the generation of the hydroxyl group was suppressed.

[Production and evaluation of wiring board]
As shown in FIG. 2, a test wiring board 1 having a conductive foil (electrolytic copper foil) having a corrugated pattern formed on the stretchable resin layer 3 and the stretchable resin layer 3 as the conductor layer 5 was produced. . First, an etching resist (made by Hitachi Chemical Co., Ltd., trade name “Photech RY-5325”) is applied to the roll laminator on the conductor layers of the conductor substrates obtained in the examples in which the surface of the stretchable resin layer has irregularities and comparative examples. A photo tool having a corrugated pattern was adhered thereto. The etching resist was exposed with an energy amount of 50 mJ / cm ² using an EXM-1201 type exposure machine manufactured by Oak Manufacturing Co., Ltd. Next, spray development was performed for 240 seconds with a 1% by mass aqueous sodium carbonate solution at 30 ° C. to dissolve the unexposed portions of the etching resist, thereby forming a resist pattern having corrugated openings. Subsequently, the copper foil of the part which is not covered with the resist pattern was removed with the etching liquid. Thereafter, the etching resist is removed with a stripping solution, and the wiring substrate 1 having a conductor layer 5 on the stretchable resin layer 3 having a wiring width of 50 μm and forming a wavy wiring pattern meandering along a predetermined direction X. Got.

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

As is apparent from the results shown in Table 1, the conductor substrates of Examples 1 to 6 have excellent stretchability and a low dielectric loss tangent as compared with the conductor substrates of Comparative Examples 1 and 2. confirmed. Further, as is apparent from the results shown in Tables 2 and 3, it was confirmed that the conductor substrates of Examples 1 to 6 can 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 as a substrate for wearable devices, for example.

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

Claims

An elastic resin layer;
A conductive substrate having a conductive foil provided on the stretchable resin layer,
A conductive substrate, wherein the stretchable resin layer includes a cured product of a resin composition containing (A) a rubber component, (B) a crosslinking component having an epoxy group, and (C) an ester curing agent.
The conductor substrate according to claim 1, wherein the elastic modulus of the conductor foil is 40 to 300 GPa.
An elastic resin layer;
A conductor plating film provided on the stretchable resin layer, and a conductor substrate,
A conductive substrate, wherein the stretchable resin layer includes a cured product of a resin composition containing (A) a rubber component, (B) a crosslinking component having an epoxy group, and (C) an ester curing agent.
The conductor substrate according to any one of claims 1 to 3, wherein a recovery rate after the elastic resin layer is tensilely deformed to a strain of 20% is 80% or more.
The rubber component (A) is acrylic rubber, isoprene rubber, butyl rubber, styrene butadiene rubber, butadiene rubber, acrylonitrile butadiene rubber, silicone rubber, urethane rubber, chloroprene rubber, ethylene propylene rubber, fluorine rubber, sulfurized rubber, epichlorohydrin rubber, and The conductor substrate according to any one of claims 1 to 4, comprising at least one rubber selected from the group consisting of chlorinated butyl rubbers.
The conductive substrate according to any one of claims 1 to 5, wherein the rubber component (A) includes a rubber having a crosslinking group.
The conductor substrate according to claim 6, wherein the cross-linking group is at least one of an acid anhydride group or a carboxyl group.
The conductive substrate according to any one of claims 1 to 7, wherein the resin composition further contains (D) a curing accelerator.
The content of the (A) rubber component is 60 to 95% by mass based on the total amount of the (A) rubber component, the (B) crosslinking component and the (C) ester curing agent. The conductor substrate according to any one of 1 to 8.
The conductor substrate according to any one of claims 1 to 9, wherein the resin composition further contains an antioxidant.
A wiring board comprising the conductive board according to claim 1 or 2, wherein the conductive foil forms a wiring pattern.
A wiring board comprising the conductive board according to claim 3, wherein the conductive plating film forms a wiring pattern.
A stretchable device comprising the wiring board according to claim 11 or 12 and an electronic element mounted on the wiring board.
A conductive board having a stretchable resin layer and a conductive foil provided on the stretchable resin layer, wherein the conductive foil forms a wiring pattern, and is used to form a wiring board. Item 3. The conductive substrate according to Item 1 or 2.
A conductive substrate having a stretchable resin layer and a conductive plating film provided on the stretchable resin layer is used to form a wiring substrate in which the conductive plating film forms a wiring pattern. The conductor substrate according to claim 3.
Preparing a laminate having a stretchable resin layer and a conductive foil laminated on the stretchable resin layer;
Forming an etching resist on the conductor foil;
Exposing the etching resist, developing the exposed etching resist to form a resist pattern covering a part of the conductor foil;
Removing the portion of the conductor foil not covered by the resist pattern;
The method for manufacturing a wiring board according to claim 11, comprising a step of removing the resist pattern.
Forming a plating resist on the stretchable resin layer;
Exposing the plating resist, developing the exposed plating resist, and forming a resist pattern covering a part of the stretchable resin layer;
Forming a conductive plating film by electroless plating on the surface of the portion of the stretchable resin layer not covered by the resist pattern;
The method of manufacturing the wiring board of Claim 12 including the process of removing the said resist pattern.
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, developing the exposed plating resist, and forming a resist pattern covering a part of the stretchable resin layer;
A step of further forming a conductor plating film by electrolytic plating on the conductor plating film in a portion not covered by the resist pattern;
Removing the resist pattern;
The method of manufacturing the wiring board of Claim 12 including the process of removing the part which is not covered with the conductor plating film formed of electrolytic plating among the said conductor plating films formed of electroless plating. .
Forming an etching resist on the conductor plating film formed on the stretchable resin layer;
Exposing the etching resist, developing the exposed etching resist, and forming a resist pattern covering a part of the stretchable resin layer;
Removing the portion of the conductor plating film not covered with the resist pattern;
Removing the resist pattern;
The method of manufacturing the wiring board of Claim 12 containing this.