JP2019160965A - Conductor substrate, wiring board, and method for manufacturing them - Google Patents

Abstract

To provide a conductor substrate which enables manufacturing of a wiring board simply with high productivity, the wiring board having excellent handleability and elasticity.SOLUTION: A conductor substrate comprises an elastic resin layer and a conductor foil or conductor plating film provided on one main surface of the elastic resin layer, in which a surface roughness Ra value of the other main surface of the elastic resin layer is 0.1 μm or more.SELECTED DRAWING: None

Description

  One aspect of the present invention relates to a wiring board that can have high stretchability and a method for manufacturing the same. Another aspect of the present invention relates to a conductor substrate that can be used to form such a wiring substrate and a method for manufacturing the same.

  In recent years, in the field of wearable devices and healthcare-related devices, for example, flexibility and stretchability have been demanded so that they can be used along curved surfaces or joints of the body, and connection failure hardly occurs even when they are 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 resin composition capable of forming a flexible resin layer having stretchability. In patent document 1, the application to the sealing use of the resin composition which can form the flexible resin layer which has a stretching property is mainly examined.

International Publication No. 2016/080346

  As a technique for imparting stretchability to a wiring board, a pre-stretching method has been proposed in which a metal thin film is deposited on a previously stretched board and the wrinkle-like metal wiring is formed by relaxing the stretching. However, this method requires a long vacuum process for forming a conductor by metal vapor deposition, and is not sufficient in terms of production efficiency.

  There has also been proposed a method for easily forming a stretchable wiring by printing using a stretchable conductive paste in which conductive particles and the like are dispersed in a stretchable elastomer. However, the wiring made of the conductive paste has a problem that the resistance value at the time of expansion increases in addition to the high resistance value as compared with the metal wiring.

  In addition, since a flexible resin layer (stretchable resin layer) having high stretchability tends to have relatively high adhesiveness, a wiring board having a stretchable resin layer and a conductor board that can form the wiring board are included. There is room for improvement in handling.

  Under such circumstances, an object of one aspect of the present invention is to provide a conductor substrate that enables easy production of a wiring board having excellent handleability and stretchability with high productivity. .

  As a result of intensive studies, the present inventors have found that the above problem can be solved by combining a stretchable resin layer and a conductive foil. That is, one aspect of the present invention has a stretchable resin layer and a conductive foil provided on one main surface of the stretchable resin layer, and the surface roughness of the other main surface of the stretchable resin layer. A conductor substrate having an Ra value of 0.1 μm or more is provided.

  Furthermore, the present inventors have found that the above problem can be solved by forming a conductor plating film as a conductor layer on the stretchable resin layer. That is, another aspect of the present invention includes a stretchable resin layer and a conductive plating film provided on one main surface of the stretchable resin layer, and the other main surface of the stretchable resin layer. Provided is a conductor substrate having a surface roughness Ra value of 0.1 μm or more.

  The conductor substrate according to one aspect of the present invention can easily manufacture a wiring substrate having excellent handleability and stretchability with high productivity. The conductor substrate according to some aspects of the present invention can have high heat resistance. In addition, the stretchable wiring board according to one aspect of the present invention can be easily manufactured from a conductor board with high productivity.

It is a stress-strain curve which shows the example of a measurement of a 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.

  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 main surface of the stretchable resin layer, and the surface roughness Ra of the other main surface of the stretchable resin layer. The value is 0.1 μm or more. The wiring board which concerns on one Embodiment has a stretchable resin layer and the conductor layer which is provided on the single side | surface or both surfaces of the stretchable resin layer, and forms the 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, there is a tendency that the conductor foil is not easily broken by the extension of the wiring board. From the same viewpoint, the elastic modulus of the conductor foil may be 50 GPa or more or 280 GPa or more, and may be 60 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 substrate.

  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 ELECTRIC CO., LTD.). Company-made, product name), GTS-18 (Furukawa Electric Co., Ltd., trade name), and F2-WS-12 (Furukawa Electric Co., Ltd., trade name). As rolled copper foil, for example, 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 process. 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 value 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 value of the roughened surface may be 0.3 to 1.5 μm.

The surface roughness Ra value 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 of coating a carrier film to form a resin layer, and laminating the formed resin layer 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 attaching 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 required 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.

  Furthermore, 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, for example, a mixed solution of concentrated sulfuric acid and hydrogen peroxide, a ferric chloride solution, or the like can be used as an etching solution used for etching.

  In order to improve the adhesive strength with the conductor 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 (manufactured by Nippon Electrolytic 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.

  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 of forming a resin layer (stretchable resin composition layer) 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.

  A surface treatment may be applied to the stretchable resin layer for the purpose of achieving high adhesion with the conductor 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 surface roughness Ra value of the principal surface where the conductive layer of the stretchable resin layer is not provided is 0.1 μm or more. When the Ra value is 0.1 μm or more, the adhesiveness of the surface of the stretchable resin layer is low, and the handleability is excellent. From the same viewpoint, the Ra value is preferably 0.2 μm or more, more preferably 0.3 μm or more, and particularly preferably 0.4 μm or more. The upper limit of the Ra value is not particularly limited, but may be 2.0 μm or less from the viewpoint of the substrate strength.

  The surface roughness Ra value can be measured using, for example, a step gauge (manufactured by Kosaka Laboratory Ltd., ET-200).

Tackiness can be evaluated by a tack value. When the tack value is high, the tackiness is high, and when the tack value is low, the tackiness is low. Tack values of the main surface provided with no conductive layer of stretchable resin layer is preferably from 0.7gf / mm ² or less (6.9 kPa or less), 0.5 gf / mm ² or less (4.9 kPa or less) More preferably, it is 0.4 gf / mm ² or less (3.9 kPa or less). The lower limit value of the tack value is not particularly limited, and may be 0 gf / mm ² (0 kPa). The tack value can be measured using, for example, a tacking tester (“TACII” manufactured by Reska Co., Ltd.).

  By imparting irregularities to the stretchable resin layer, the surface roughness Ra value of the stretchable resin layer can be within the above range. Although there is no particular limitation on the method for imparting irregularities to the stretchable resin layer, for example, an irregularity pattern can be formed using an irregularity transfer substrate on the stretchable resin layer in the B-stage state or the stretchable resin layer after the curing reaction. A method of peeling the concavo-convex transfer substrate after transfer is conceivable. Moreover, the method of giving imprint processes, such as an etching process and a thermal imprint process, to the elastic resin layer after hardening reaction is also considered. Furthermore, a method of pressing the roughened surface of the metal foil to the stretchable resin layer and etching the metal foil layer is also conceivable. However, the method for imparting irregularities to the stretchable resin layer is not limited to these examples.

  In this embodiment, use of an impression material is mentioned as one of the methods of providing an unevenness | corrugation to an elastic resin layer. An impression material is a material that can accurately transfer a high-definition three-dimensional structure. The structure can be transferred to the substrate by pressing the impression material to which the structure has been transferred onto the substrate and removing the impression material. Examples of the material for the impression material include agar, alginate, polysulfide rubber, polyether rubber, and silicone elastomer. From the viewpoint of releasability between the impression material and the substrate when the impression material is removed from the substrate after transferring the structure to the substrate, the material of the impression material is preferably a silicone elastomer.

  As a method for imparting unevenness to the stretchable resin layer using an impression material, for example, the impression material is applied to the roughened surface of a metal foil having a roughened surface, and the obtained coating film is dried with a dryer. After that, the step of peeling the coating film from the metal foil to form a concavo-convex transfer film, laminating the concavo-convex transfer film on the stretchable resin layer, and then peeling the concavo-convex transfer film to form the concavo-convex in the stretchable resin layer Process. The metal foil having a roughened surface is not particularly limited, but can be selected depending on the surface roughness Ra value formed on the surface of the stretchable resin layer. For example, electrolytic copper foil F1-WS-18 (Furukawa Electric Co., Ltd.) Co., Ltd., surface roughness Ra value of roughened surface: 0.3 μm), electrolytic copper foil F0-WS-18 (manufactured by Furukawa Electric Co., Ltd., surface roughness Ra value of roughened surface: 0.2 μm) Can be mentioned. For the lamination, for example, a vacuum pressure laminator can be used. Moreover, the surface roughness Ra value of the surface of the stretchable resin layer can be adjusted by selecting the conditions for the lamination (for example, pressure, temperature, pressurization time, etc.).

  A laminate having conductor foils formed on both sides of the stretchable resin layer may be prepared by laminating a conductor foil having a roughened surface on the main surface where the conductor foil of the stretchable resin layer is not provided. . By forming the conductor layer on both surfaces of the stretchable resin layer, it is possible to suppress warping of the laminated board during curing. By removing unnecessary portions of the conductive foil, the unevenness of the roughened surface of the conductive foil is transferred to the stretchable 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 stretchable resin layer can contain (A) a rubber component. Mainly, the rubber component easily imparts stretchability to the stretchable resin layer. 30-100 mass%, 50-100 mass%, or 70-100 mass% may be sufficient as content of a rubber component with respect to 100 mass% of elastic resin layers.

  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 chlorinated rubber. At least one rubber selected from the group consisting of butyl rubber can be included. 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 may include 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 commercial products of acrylic rubber include ZEON Corporation “Nipol AR Series” and Kuraray Co., Ltd. “Clarity Series”.

  As a commercial product of isoprene rubber, for example, Nippon Zeon Co., Ltd. “Nipol IR Series” can be mentioned.

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

  Examples of commercially available styrene butadiene rubber include JSR Corporation “Dynalon SEBS Series”, “Dynalon 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".

  As a commercial item of acrylonitrile butadiene rubber, for example, JSR Corporation “JSR NBR series” can be cited.

  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”.

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

  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.

  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 cross-linking group may be a reactive group capable of causing a reaction to cross-link the molecular chain of the rubber component. 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.

  The rubber component may include 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 styrenic 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 styrene-based 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”.

  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).

  The stretchable resin layer may be a cured product of a resin composition containing (A) a rubber component. In this case, a curable resin composition is used as the resin composition for forming the stretchable resin layer. This curable resin composition may further contain, for example, (B) a crosslinking component. That is, the stretchable resin layer may further contain (B) a crosslinked polymer of a crosslinking component. The cross-linking component is, for example, selected from the group consisting of (meth) acryloyl group, vinyl group, epoxy group, styryl group, amino group, isocyanurate group, ureido group, cyanate group, isocyanate group, mercapto group, hydroxyl group, and carboxyl group It may be a compound having at least one kind of reactive group, and a cured product containing a crosslinked polymer can be formed by the reaction of these reactive groups. From the viewpoint of improving the heat resistance of the stretchable resin layer, the crosslinking component may be a compound having a reactive group selected from an epoxy group, an amino group, a hydroxyl group, and a carboxyl group. These compounds can be used alone or in combination of two or more.

  Examples of the compound having a (meth) acryloyl group include (meth) acrylate compounds. The (meth) acrylate compound may be monofunctional, bifunctional or polyfunctional, and is not particularly limited, but may be a bifunctional or polyfunctional (meth) acrylate in order to obtain sufficient curability. .

  Examples of the monofunctional (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, butoxyethyl (meth) acrylate, Isoamyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, heptyl (meth) acrylate, octylheptyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, undecyl (meth) acrylate , Lauryl (meth) acrylate, tridecyl (meth) acrylate, tetradecyl (meth) acrylate, pentadecyl (meth) acrylate, hexadecyl (meth) acrylate, stearyl (Meth) acrylate, behenyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, Aliphatics such as methoxypolyethylene glycol (meth) acrylate, ethoxypolyethyleneglycol (meth) acrylate, methoxypolypropyleneglycol (meth) acrylate, ethoxypolypropyleneglycol (meth) acrylate, mono (2- (meth) acryloyloxyethyl) succinate ( (Meth) acrylate; cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, cyclopentyl (meth) acrylate, dicyclopentanyl (meth) ) Acrylate, dicyclopentenyl (meth) acrylate, isobornyl (meth) acrylate, mono (2- (meth) acryloyloxyethyl) tetrahydrophthalate, mono (2- (meth) acryloyloxyethyl) hexahydrophthalate Cyclic (meth) acrylate; benzyl (meth) acrylate, phenyl (meth) acrylate, o-biphenyl (meth) acrylate, 1-naphthyl (meth) acrylate, 2-naphthyl (meth) acrylate, phenoxyethyl (meth) acrylate, p-cumylphenoxyethyl (meth) acrylate, o-phenylphenoxyethyl (meth) acrylate, 1-naphthoxyethyl (meth) acrylate, 2-naphthoxyethyl (meth) acrylate, phenoxypolyethyleneglycol (Meth) acrylate, nonylphenoxypolyethylene glycol (meth) acrylate, phenoxypolypropylene glycol (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, 2-hydroxy-3- (o-phenylphenoxy) propyl Aromatic (meth) acrylates such as (meth) acrylate, 2-hydroxy-3- (1-naphthoxy) propyl (meth) acrylate, 2-hydroxy-3- (2-naphthoxy) propyl (meth) acrylate; 2-tetrahydro Heterocyclic (meth) acrylates such as furfuryl (meth) acrylate, N- (meth) acryloyloxyethyl hexahydrophthalimide, 2- (meth) acryloyloxyethyl-N-carbazole, and their caprolactone modifications Body, and the like. Among these, a monofunctional (meth) acrylate may be selected from the above aliphatic (meth) acrylate and the above aromatic (meth) acrylate from the viewpoint of compatibility with the styrene-based elastomer, transparency and heat resistance.

  Examples of the bifunctional (meth) acrylate include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, and polyethylene glycol di (meth) acrylate. , Propylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, tetrapropylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, ethoxylated polypropylene glycol di ( (Meth) acrylate, 1,3-butanediol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, neopentyl Recall di (meth) acrylate, 3-methyl-1,5-pentanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 2-butyl-2-ethyl-1,3-propanediol di ( (Meth) acrylate, 1,9-nonanediol di (meth) acrylate, 1,10-decanediol di (meth) acrylate, glycerin di (meth) acrylate, tricyclodecane dimethanol (meth) acrylate, ethoxylated 2-methyl Aliphatic (meth) acrylates such as 1,3-propanediol di (meth) acrylate; cyclohexanedimethanol (meth) acrylate, ethoxylated cyclohexanedimethanol (meth) acrylate, propoxylated cyclohexanedimethanol (meth) acrylate, etoxy Propoxylated cyclohexanedimethanol (meth) acrylate, tricyclodecane dimethanol (meth) acrylate, ethoxylated tricyclodecane dimethanol (meth) acrylate, propoxylated tricyclodecane dimethanol (meth) acrylate, ethoxylated propoxylated tri Cyclodecane dimethanol (meth) acrylate, ethoxylated hydrogenated bisphenol A di (meth) acrylate, propoxylated hydrogenated bisphenol A di (meth) acrylate, ethoxylated propoxylated hydrogenated bisphenol A di (meth) acrylate, ethoxylated water Alicyclic rings such as hydrogenated bisphenol F di (meth) acrylate, propoxylated hydrogenated bisphenol F di (meth) acrylate, and ethoxylated propoxylated hydrogenated bisphenol F di (meth) acrylate Formula (meth) acrylate; ethoxylated bisphenol A di (meth) acrylate, propoxylated bisphenol A di (meth) acrylate, ethoxylated propoxylated bisphenol A di (meth) acrylate, ethoxylated bisphenol F di (meth) acrylate, propoxylated Bisphenol F di (meth) acrylate, ethoxylated propoxylated bisphenol F di (meth) acrylate, ethoxylated bisphenol AF di (meth) acrylate, propoxylated bisphenol AF di (meth) acrylate, ethoxylated propoxylated bisphenol AF di (meth) Acrylate, ethoxylated fluorene di (meth) acrylate, propoxylated fluorene di (meth) acrylate, ethoxylated propoxy fluorene di (meth) acrylate Heterocyclic (meth) acrylates such as ethoxylated isocyanuric acid di (meth) acrylate, propoxylated isocyanuric acid di (meth) acrylate, ethoxylated propoxylated isocyanuric acid di (meth) acrylate, etc. Acrylates; these caprolactone modified products; aliphatic epoxy (meth) acrylates such as neopentyl glycol type epoxy (meth) acrylate; cyclohexanedimethanol type epoxy (meth) acrylate, hydrogenated bisphenol A type epoxy (meth) acrylate, hydrogenated Alicyclic epoxy (meth) acrylates such as bisphenol F type epoxy (meth) acrylate; resorcinol type epoxy (meth) acrylate, bisphenol A type epoxy (meth) acrylate, bisphenol Type epoxy (meth) acrylate, bisphenol AF type epoxy (meth) acrylates, and aromatic epoxy (meth) acrylates such as fluorene epoxy (meth) acrylate. Among these, bifunctional (meth) acrylates may be selected from the above aliphatic (meth) acrylates and the above aromatic (meth) acrylates from the viewpoints of compatibility with styrene-based elastomers, transparency, and heat resistance.

  Examples of the trifunctional or higher polyfunctional (meth) acrylate include trimethylolpropane tri (meth) acrylate, ethoxylated trimethylolpropane tri (meth) acrylate, propoxylated trimethylolpropane tri (meth) acrylate, and ethoxylated propoxylated tri Methylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, ethoxylated pentaerythritol tri (meth) acrylate, propoxylated pentaerythritol tri (meth) acrylate, ethoxylated propoxylated pentaerythritol tri (meth) acrylate, pentaerythritol Tetra (meth) acrylate, ethoxylated pentaerythritol tetra (meth) acrylate, propoxylated pentaerythritol tetra (me ) Aliphatic (meth) acrylates such as acrylate, ethoxylated propoxylated pentaerythritol tetra (meth) acrylate, ditrimethylolpropane tetraacrylate, dipentaerythritol hexa (meth) acrylate; ethoxylated isocyanuric acid tri (meth) acrylate, propoxylated Heterocyclic (meth) acrylates such as isocyanuric acid tri (meth) acrylate and ethoxylated propoxylated isocyanuric acid tri (meth) acrylate; these caprolactone modified products; phenol novolac type epoxy (meth) acrylate, cresol novolac type epoxy (meta) ) Aromatic epoxy (meth) acrylates such as acrylate. Among these, polyfunctional (meth) acrylates may be selected from the above aliphatic (meth) acrylates and the above aromatic (meth) acrylates from the viewpoints of compatibility with styrene-based elastomers, transparency, and heat resistance.

  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, And the especially outstanding effect is acquired at the point of the low tack property of the resin layer after hardening. 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 cured resin layer has low tackiness, the conductor substrate or the wiring substrate can be handled with good workability.

  The compound containing an epoxy group is not particularly limited as long as it has an epoxy group in the 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 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 tack, and heat resistance, a phenol novolac type, a cresol novolac type, a naphthalene type, and a dicyclopentadiene type may be selected. These epoxy resins can be used alone or in combination of two or more.

  The content of the crosslinked polymer formed from the crosslinking component may be 10 to 50% by mass based on the mass of the stretchable resin layer. If the content of the cross-linked polymer formed from the cross-linking component is in the above range, the adhesion with the conductor foil or the conductor plating film tends to be improved while maintaining the properties of the stretchable resin layer. From the above viewpoint, the content of the crosslinked polymer formed from the crosslinking component may be 15 to 40% by mass. The content of the crosslinking component in the resin composition for forming the stretchable resin layer may be within these ranges.

  The stretchable resin layer or the resin composition used to form it can further contain an additive as the component (C). (C) The additive may be at least one of a curing agent or a curing accelerator. The curing agent is a compound that itself participates in the curing reaction, and the curing accelerator is a compound that functions as a catalyst for the curing reaction. A compound having both functions of a curing agent and a curing accelerator can also be used. The curing agent may be a polymerization initiator. These can be appropriately selected according to other components contained in the resin composition. For example, if it is a resin composition containing a (meth) acrylate compound, a polymerization initiator may be added. The polymerization initiator is not particularly limited as long as it initiates polymerization by heating or irradiation with ultraviolet rays or the like. For example, a thermal radical polymerization initiator or a photo radical polymerization initiator can be used. The thermal radical polymerization initiator tends to allow the reaction of the resin composition to proceed uniformly. Since the radical photopolymerization initiator can be cured at room temperature, it is advantageous in that it prevents deterioration of the device due to heat and can suppress warping of the stretchable resin layer.

  Examples of the thermal radical polymerization initiator include ketone peroxides such as methyl ethyl ketone peroxide, cyclohexanone peroxide, and methylcyclohexanone peroxide; 1,1-bis (t-butylperoxy) cyclohexane, 1,1-bis (t- Butylperoxy) -2-methylcyclohexane, 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (t-hexylperoxy) cyclohexane, 1,1- Peroxyketals such as bis (t-hexylperoxy) -3,3,5-trimethylcyclohexane; hydroperoxides such as p-menthane hydroperoxide; α, α′-bis (t-butylperoxy) diisopropylbenzene , Dicumyl peroxide, t-butyl cumylper Dialkyl peroxides such as oxide and di-t-butyl peroxide; diacyl peroxides such as octanoyl peroxide, lauroyl peroxide, stearyl peroxide and benzoyl peroxide; bis (4-t-butylcyclohexyl) peroxydicarbonate Peroxycarbonates such as di-2-ethoxyethyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, di-3-methoxybutyl peroxycarbonate; t-butyl peroxypivalate, t-hexyl peroxy Pivalate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, 2,5-dimethyl-2,5-bis (2-ethylhexanoylperoxy) hexane, t-hexylper Oxy-2-e Ruhexanoate, t-butylperoxy-2-ethylhexanoate, t-butylperoxyisobutyrate, t-hexylperoxyisopropyl monocarbonate, t-butylperoxy-3,5,5-trimethylhexanoate, t-butyl peroxylaurate, t-butyl peroxyisopropyl monocarbonate, t-butyl peroxy-2-ethylhexyl monocarbonate, t-butyl peroxybenzoate, t-hexyl peroxybenzoate, 2,5-dimethyl-2 Peroxyesters such as 2,5-bis (benzoylperoxy) hexane and t-butylperoxyacetate; 2,2′-azobisisobutyronitrile, 2,2′-azobis (2,4-dimethylvaleronitrile) 2,2′-azobis (4-me Carboxymethyl-2'-dimethylvaleronitrile), and the azo compounds such as. Among these, from the viewpoint of curability, transparency, and heat resistance, a thermal radical polymerization initiator may be selected from the diacyl peroxide, the peroxyester, and the azo compound.

  Examples of the radical photopolymerization initiator include benzoin ketals such as 2,2-dimethoxy-1,2-diphenylethane-1-one; 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropane- Α-hydroxy ketones such as 1-one, 1- [4- (2-hydroxyethoxy) phenyl] -2-hydroxy-2-methyl-1-propan-1-one; 2-benzyl-2-dimethylamino-1 Α-amino ketones such as-(4-morpholinophenyl) -butan-1-one, 1,2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one; Oxime esters such as (4-phenylthio) phenyl] -1,2-octadion-2- (benzoyl) oxime; bis (2,4,6 Phosphine oxides such as -trimethylbenzoyl) phenylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide; Chlorophenyl) -4,5-diphenylimidazole dimer, 2- (o-chlorophenyl) -4,5-di (methoxyphenyl) imidazole dimer, 2- (o-fluorophenyl) -4,5-diphenylimidazole 2,4,5-tria such as dimer, 2- (o-methoxyphenyl) -4,5-diphenylimidazole dimer, 2- (p-methoxyphenyl) -4,5-diphenylimidazole dimer Reel imidazole dimer; benzophenone, N, N′-tetramethyl-4, Benzophenone compounds such as' -diaminobenzophenone, N, N'-tetraethyl-4,4'-diaminobenzophenone, 4-methoxy-4'-dimethylaminobenzophenone; 2-ethylanthraquinone, phenanthrenequinone, 2-tert-butylanthraquinone, Octamethylanthraquinone, 1,2-benzanthraquinone, 2,3-benzanthraquinone, 2-phenylanthraquinone, 2,3-diphenylanthraquinone, 1-chloroanthraquinone, 2-methylanthraquinone, 1,4-naphthoquinone, 9,10- Quinone compounds such as phenanthraquinone, 2-methyl-1,4-naphthoquinone, 2,3-dimethylanthraquinone; benzoin methyl ether, benzoin ethyl ether, benzoin phenyl ether Benzoin ethers; benzoin compounds such as benzoin, methylbenzoin and ethylbenzoin; benzyl compounds such as benzyldimethyl ketal; acridine compounds such as 9-phenylacridine and 1,7-bis (9,9′-acridinylheptane): N-phenylglycine, coumarin and the like can be mentioned.

  In the 2,4,5-triarylimidazole dimer, the substituents of the aryl groups at the two triarylimidazole sites may give the same and symmetric compounds or differently give asymmetric compounds . A thioxanthone compound and a tertiary amine may be combined, such as a combination of diethylthioxanthone and dimethylaminobenzoic acid.

  Among these, from the viewpoint of curability, transparency, and heat resistance, a radical photopolymerization initiator may be selected from the α-hydroxyketone and the phosphine oxide. These thermal and photo radical polymerization initiators can be used alone or in combination of two or more. Further, it can be combined with an appropriate sensitizer.

  When the curable resin composition for forming the stretchable resin layer contains (A) a rubber component, (B) a crosslinking component, and a curing agent as the (C) component, it contains a curing agent (or a polymerization initiator). 0.1-10 mass parts may be sufficient with respect to 100 mass parts of total amounts of a rubber component and a crosslinking component. When the content of the curing agent (or polymerization initiator) is 0.1 parts by mass or more, sufficient curing tends to be easily obtained. When the content of the curing agent (or polymerization initiator) is 10 parts by mass or less, sufficient light transmittance tends to be easily obtained. From the above viewpoint, the content of the curing agent (or polymerization initiator) may be 0.3 to 7 parts by mass, or 0.5 to 5 parts by mass.

  The curing agent may contain at least one selected from the group consisting of aliphatic polyamines, polyaminoamides, polymercaptans, aromatic polyamines, acid anhydrides, carboxylic acids, phenol novolac resins, ester resins, and dicyandiamide. These curing agents can be combined with, for example, a compound having an epoxy group (epoxy resin).

  You may add the hardening accelerator chosen from a tertiary amine, an imidazole, an acid anhydride, and a phosphine as (C) component to the resin composition containing an epoxy resin. From the viewpoint of storage stability and curability of the varnish, imidazole may be used. When the rubber component includes a rubber partially modified with maleic anhydride, an imidazole compatible with the rubber may be selected.

  When the resin composition for forming the stretchable resin layer contains (A) a rubber component and (B) a crosslinking component, the content of imidazole is 100 parts by mass with respect to the total amount of the rubber component and the crosslinking component. 0.1-10 mass parts may be sufficient. When the content of imidazole is 0.1 parts by mass or more, sufficient curing tends to be easily obtained. When the content of imidazole is 10 parts by mass or less, sufficient heat resistance tends to be obtained. From the above viewpoint, the content of imidazole may be 0.3 to 7 parts by mass, or 0.5 to 5 parts by mass.

  When the resin composition for forming the stretchable resin layer contains (A) a rubber component, (B) a crosslinking component, and (C) an additive, the content of the rubber component is (A) the rubber component, (B ) 30 to 98% by mass, 50 to 97% by mass, or 60 to 95% by mass based on the total amount of the crosslinking component and (C) component. When the content of the rubber component is 30% by mass or more, sufficient stretchability is easily obtained. When the content of the rubber component is 98% by mass or less, the stretchable resin layer tends to have particularly excellent characteristics in terms of adhesion, insulation reliability, and heat resistance.

  In addition to the above components, the stretchable resin layer or the resin composition for forming the resin layer may contain an antioxidant, a yellowing inhibitor, an ultraviolet absorber, a visible light absorber, a colorant, a plasticizer, if necessary. An agent, a stabilizer, a filler, a flame retardant, a leveling agent, and the like may be further included within a range that does not significantly impair the effects of the present invention.

  In particular, the stretchable resin layer or the resin composition for forming the stretched resin layer contains at least one degradation inhibitor selected from the group consisting of an antioxidant, a heat stabilizer, a light stabilizer, and a hydrolysis inhibitor. You may contain. 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 substituent having a large steric hindrance such as a t-butyl group (tertiarybutyl 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-tert-butylphenol), 4,4′-thiobis- (3-methyl-6-tert-butylphenol), 4,4′-butylidenebis (3-methyl-6-tert-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) 1 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 more compounds. The phenolic antioxidants are 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene and tetrakis- [methylene-3- (3 ′ , 5′-di-t-butyl-4′-hydroxyphenyl) propionate] may be a high-molecular phenolic antioxidant represented by methane.

  Examples of the phosphite antioxidant include triphenyl phosphite, diphenylisodecyl phosphite, phenyl diisodecyl phosphite, 4,4′-butylidene-bis (3-methyl-6-tert-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, diisodecylpentaerythritol diphosphite and tris One or more compounds selected from the group consisting of bis (2,4-di-t-butylphenyl) phosphite, and tris (2,4-di-t-butylphenyl) phosphite, Also good.

  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.

  0.1-20 mass% may be sufficient as content of antioxidant based on the mass of a stretchable resin layer or the resin composition for forming this. 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 zinc and barium salts of higher fatty acids, organic tin compounds such as organic tin maleates and organic tin mercapts, 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 preventing agents 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 rubber component and other components as necessary in an organic solvent to obtain a resin varnish, and forming the resin varnish on a conductor foil or a carrier film by a method described later. Can be manufactured by a method including.

  The organic solvent used here is not particularly limited, but 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, and 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. 20-80 mass% may be sufficient as solid content (components other than an organic solvent) density | concentration in a resin varnish.

  The carrier film is not particularly limited. For example, polyethylene terephthalate (PET), polybutylene terephthalate, polyethylene naphthalate, polycarbonate and other polyesters; polyethylene, polypropylene and other polyolefins; polyamide, polyimide, polyamideimide, polyetherimide, poly Examples 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 base film to a release treatment with a silicone compound, a fluorine-containing compound, or the like may be used as necessary.

  As needed, it is good also as a laminated film of the 3 layer structure which affixes a protective film on a stretchable resin layer, and consists of conductor foil or a carrier film, a stretchable resin layer, and a protective film.

  The protective film is not particularly limited, and examples thereof include polyesters such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; and polyolefins such as polyethylene and polypropylene. 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 conductor substrate]
The conductor substrate according to this embodiment includes a step of preparing a laminate having a stretchable resin layer and a conductor foil or a conductor plating film provided on one main surface of the stretchable resin layer, and a stretchable resin layer. And a step of forming irregularities on the other main surface so that the surface roughness Ra value is 0.1 μm or more.

  As a method for obtaining a laminate (a laminate for forming a wiring board) having a stretchable resin layer and a conductive foil, any method may be used, but a resin composition for forming a stretchable resin layer may be used. There are a method of coating a varnish on a conductor foil, a method of laminating a conductor foil on a stretchable resin layer formed on a carrier film by a vacuum press, a laminator, and the like. When the resin composition for forming the stretchable resin layer does not contain a crosslinking component, the stretchable resin layer can be formed by drying the coating film of the resin composition. When the resin composition for forming the stretchable resin layer contains a crosslinking component, after the coating film of the resin composition is dried, the crosslinking reaction (curing reaction) of the crosslinking component proceeds by heating or light irradiation. A stretchable resin layer can be formed.

  As a method of laminating the stretchable resin layer on the carrier film on the conductor foil, any method may be used, 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.

  Although the thickness after drying of an elastic resin layer is not specifically limited, Usually, it is 5-1000 micrometers. When the amount is in the above range, sufficient strength as a stretchable base material can be easily obtained and drying can be sufficiently performed, so that the amount of residual solvent in the resin layer can be reduced.

  You may produce the laminated board by which conductor foil was formed on both surfaces of the elastic resin layer by further laminating | stacking conductor foil on the surface on the opposite side to the conductor foil of an elastic resin layer. 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 obtaining a laminated board (laminated board for wiring board formation) having a stretchable resin layer and a conductor plating film, it was formed on a carrier film by, for example, a normal plating method used in an additive method or a semi-additive method. There is a method of forming a conductor plating film on the stretchable resin layer.

  The details of the method for forming irregularities in the stretchable resin layer are as described above.

<Wiring board>
The wiring board according to this embodiment is manufactured by a method including a step of forming a wiring pattern on the conductor foil or the conductor plating film of the conductor board according to this embodiment. As a technique for forming a wiring pattern on the conductor foil or the conductor plating film, a technique using etching, plating, or the like is generally used.

  When forming a wiring pattern by etching, for example, the wiring substrate according to the present embodiment exposes the etching resist with a step of forming an etching resist on the conductive foil or the conductive plating film of the conductive substrate according to the present embodiment, The step of developing the exposed etching resist to form a resist pattern that covers a portion of the conductor foil or conductor plating film, and the portion of the conductor foil or conductor plating film not covered by the resist pattern is removed with an etching solution It can be manufactured by a method including a step and a step of removing a resist pattern.

  Etching resists used for etching include, for example, Photec H-7525 (trade name, manufactured by Hitachi Chemical Co., Ltd.), Photech H-7030 (trade name, manufactured by Hitachi Chemical Co., Ltd.), Photech RY-5325 (manufactured by Hitachi Chemical Co., Ltd., Product name) and X-87 (trade name, manufactured by Taiyo Holdings Co., Ltd.). The etching resist is usually removed after the wiring pattern is formed.

  The etching solution can be selected as appropriate. For example, when copper foil is used as the conductor foil or when the conductor plating film is copper plating, for example, a mixed solution of concentrated sulfuric acid and hydrogen peroxide solution, ferric chloride solution, etc. Can be used.

  When forming a wiring pattern by plating, the wiring board according to the present embodiment, for example, a step of forming a plating resist on the conductor foil or conductor plating film of the conductive substrate according to the present embodiment, and exposing the plating resist, Developing the exposed plating resist to form a resist pattern covering a portion of the conductor foil or conductor plating film, and electroless plating on the portion of the conductor foil or conductor plating film not covered by the resist pattern Alternatively, a step of further forming a conductive plating film by electrolytic plating, a step of removing the resist pattern, and a portion of the conductive foil or conductive plating film that is not covered with the conductive plating film formed by the electrolytic plating is removed. It can manufacture by the method including a process.

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

Study 1
1-1. Preparation of varnish for resin layer formation [Resin varnish A]
As a component, 30 g of hydrogenated styrene butadiene rubber (manufactured by Asahi Kasei Corporation, Tuftec P1500, trade name) and 70 g of toluene as a solvent were mixed with stirring to obtain a resin varnish A.

[Resin varnish B]
Hydrogenated styrene butadiene rubber (manufactured by JSR Corporation, Dynalon 2324P, trade name) 20 g as component (A), butanediol acrylate (manufactured by Hitachi Chemical Co., Ltd., funkrill FA-124AS, trade name) 5 g as component (B) And 0.4 g of bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide (manufactured by BASF Corporation, Irgacure 819, trade name) as a component (C) and 15 g of toluene as a solvent are mixed with stirring. Resin varnish B was obtained.

[Resin varnish C]
As component (A), 20 g of acrylic polymer (manufactured by Kuraray Co., Ltd., Clarity LA2140, trade name), as component (B), 5 g of an aliphatic chain-modified epoxy resin (manufactured by DIC Corporation, EXA4816, trade name), and as component (C) Resin varnish C was obtained by mixing 0.5 g of 2-phenylimidazole (manufactured by Shikoku Kasei Kogyo Co., Ltd., 2PZ, trade name) and 15 g of methyl ethyl ketone as a solvent while stirring.

[Resin varnish D]
25.0 g of methyl ethyl ketone was mixed with 50 g of a biphenyl aralkyl type epoxy resin (Nippon Kayaku Co., Ltd., NC-3000H, trade name). Thereto was added 20 g of a phenol novolac type phenolic resin (manufactured by DIC Corporation, TD2131, trade name), and further 0.15 g of 2-phenylimidazole (manufactured by Shikoku Kasei Kogyo Co., Ltd., 2PZ, trade name) was added as a curing accelerator. . Then, the resin varnish D was obtained by diluting with methyl ethyl ketone.

1-2. Preparation of uneven transfer film A knife coater (“SNC-350, manufactured by Yasui Seiki Co., Ltd.) was used on the roughened surface (surface roughness Ra value: 0.3 μm) of electrolytic copper foil (F1-WS-18, manufactured by Furukawa Electric Co., Ltd.). ]) Was used to apply a silicone impression material (manufactured by Shin-Etsu Silicone Co., Ltd., SIM-260). The coating film was heat-treated at 150 ° C. for 30 minutes in a dryer (“MSO-80TPS” manufactured by Futaba Kagaku Co., Ltd.), and then the coating film was peeled off from the electrolytic copper foil. The thickness was 100 μm, and the surface roughness Ra value was 0.00. An uneven transfer film A having a thickness of 3 μm was formed.

1-3. Production Example 1-1 of Conductive Substrate 1-1
[Laminated film having stretchable resin layer]
A release-treated polyethylene terephthalate (PET) film (“Purex A31” manufactured by Teijin Film Solutions Ltd., thickness 25 μm) was prepared as a carrier film. Resin varnish A was applied onto the release-treated surface of this PET film using a knife coater (“SNC-350” manufactured by Yasui Seiki Co., Ltd.). The coating film was dried at 100 ° C. for 20 minutes in a dryer (“MSO-80TPS” manufactured by Futaba Kagaku Co., Ltd.) to form a resin layer having a thickness of 100 μm. On the formed resin layer, the same release-treated PET film as the carrier film was attached as a protective film with the release-treated surface facing the resin layer side to obtain a laminated film A. The resin layer was a stretchable resin layer having stretchability showing a recovery rate of 80% or more.

[Conductor substrate]
The protective film of the laminated film A was peeled off, and the stretchable resin layer of the laminated film A was superimposed on the roughened surface side of the copper foil (manufactured by Nippon Electrolytic Co., Ltd., YGP-12, trade name). A conductor having a stretchable resin layer and a copper foil, using a vacuum pressure laminator (“V130” manufactured by Nichigo-Morton Co., Ltd.) under pressure of 0.5 MPa, temperature of 90 ° C. and pressurization time of 60 seconds. The substrate was formed on a carrier film.

[Roughness formation on the surface of the resin layer]
The carrier film was peeled from the conductor substrate, and the uneven transfer film A was superimposed on the exposed resin layer. Using a vacuum pressure laminator (“V130” manufactured by Nichigo Morton Co., Ltd.), after pressure bonding under the conditions of a pressure of 0.5 MPa, a temperature of 90 ° C., and a pressurization time of 60 seconds, Unevenness was formed on the surface of the resin layer of the conductor substrate.

Example 1-2
Except that the resin varnish A was changed to resin varnish B and the copper foil was changed to “BHY-82F-HA-V2” (thickness 12 μm, product name, manufactured by JX Metals Co., Ltd.), the same as in Example 1-1, A conductor substrate having a copper foil and an uncured resin layer was obtained. Then, the ultraviolet light (wavelength 365nm) was irradiated with 2000mJ / cm < ² > with the ultraviolet exposure machine (Mikasa Co., Ltd. product "ML-320FSAT"), and the conductor board | substrate which has the resin layer after hardening and copper foil was obtained. Unevenness was formed on the surface of the resin layer of the obtained conductor substrate in the same manner as in Example 1-1. The cured resin layer was a stretchable resin layer having stretchability showing a recovery rate of 80% or more.

Example 1-3
A conductor substrate having a copper foil and an uncured resin layer was obtained in the same manner as in Example 1-1 except that the resin varnish A was changed to the resin varnish C. Then, the resin layer was hardened on 180 degreeC 1 hour conditions using dryer ("MSO-80TPS" by Futaba Kagaku Co., Ltd.). About the obtained conductor board | substrate, the unevenness | corrugation was formed in the resin layer surface of the conductor board | substrate similarly to Example 1-1, and the conductor board | substrate with which the unevenness | corrugation was formed in the resin layer surface was obtained. The cured resin layer was a stretchable resin layer having stretchability showing a recovery rate of 80% or more.

Comparative Example 1-1
A conductor substrate having a copper foil and an uncured resin layer was obtained in the same manner as in Example 1-1 except that the resin varnish A was changed to the resin varnish D. Thereafter, the resin layer was cured under conditions of 180 ° C. for 1 hour using a dryer (“MSO-80TPS” manufactured by Futaba Kagaku Co., Ltd.) to obtain a conductor substrate having a cured resin layer and copper foil. Unevenness was formed on the surface of the resin layer of the obtained conductor substrate in the same manner as in Example 1-1. The cured resin layer was non-stretchable with a recovery rate clearly less than 80%.

[Production and evaluation of wiring board]
As shown in FIG. 2, a test wiring board 1 having a resin layer 3 and a conductor foil having a corrugated pattern formed on the resin layer 3 as a conductor layer 5 was produced. First, an etching resist (manufactured by Hitachi Chemical Co., Ltd., Photec RY-5325, trade name) is attached with a roll laminator on the conductive layer of the conductive substrate having a concavo-convex surface formed on the resin layer surface, and a corrugated pattern is formed there. The photo tool made was stuck. 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 to obtain a wiring substrate 1 having a conductive foil 5 on the resin layer 3 on which a wiring width of 50 μm and a wavy wiring pattern meandering along a predetermined direction X are formed. It was.

  The obtained wiring board was pulled and deformed in the X direction to a strain of 10%, and the resin layer and the corrugated wiring pattern were observed when the wiring board was restored. The case where the resin layer and the wiring pattern were not broken at the time of extension was designated as “A”, and the case where the breakage occurred was designated as “C”.

[Surface roughness]
A conductor substrate having irregularities formed on the resin layer surface was prepared. The surface roughness Ra value of the exposed resin layer was measured according to JIS-B-0601 (2010 edition). The surface of the exposed resin layer of the conductive substrate was measured using a step meter (manufactured by Kosaka Laboratory Ltd., ET-200). The measurement was performed at 10 points each in the longitudinal direction and the width direction at intervals of 5 mm with a stylus tip radius of 0.5 μm, a needle pressure of 5 mg, a measurement length of 1 mm, and a cut-off of 0.08 mm. A roughness curve at each measurement location was obtained from each measurement result. The roughness curve was folded from the center line, and the surface roughness was calculated from the value obtained by dividing the area obtained by the roughness curve and the center line by the length. The average value of 20 measurement points was defined as the surface roughness Ra value of the resin layer exposed on the conductor substrate.

[Tackiness]
A conductor substrate having irregularities formed on the resin layer surface was prepared. The tack value of the surface of the exposed resin layer was measured using a tacking tester (“TACII” manufactured by Reska Co., Ltd.). The measurement conditions were set to a constant load mode, an immersion speed of 120 mm / min, a test speed of 600 mm / min, a load of 100 gf, a load holding time of 1 s, and a temperature of 30 ° C.

  Table 1 shows the evaluation results of Examples 1-1 to 1-3 and Comparative Example 1-1. In the wiring board having the corrugated wiring pattern formed by the conductor substrates of Examples 1-1 to 1-3, the stretchable resin layer does not break even when stretched by 10%, and the appearance of the corrugated wiring pattern is also good. I found that there was no problem. On the other hand, in Comparative Example 1-1, since the resin layer did not have stretchability, it was found that the resin layer was broken before stretching by 10%, and the wiring was also broken at the same time. The tack value of the resin layer of each Example was low, and the handling property of the conductor substrate was also excellent.

Study 2
Example 2-1
[Resin varnish]
(A) Maleic anhydride-modified styrene ethylene butadiene rubber (manufactured by KRATON Co., Ltd., FG1924GT, trade name) 10 g, (B) component as dicyclopentadiene type epoxy resin (DIC Corporation, EPICLON HP7200H, trade name) 2 .5 g, and 1-benzyl-2-methylimidazole (manufactured by Shikoku Kasei Kogyo Co., Ltd., 1B2MZ, trade name) 0.38 g as component (C) (curing accelerator) and 50 g of toluene as a solvent are mixed with stirring. Thus, a resin varnish was obtained.

[Laminated film]
A release-treated polyethylene terephthalate (PET) film (“Purex A31” manufactured by Teijin Film Solutions Ltd., 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 (“SNC-350” manufactured by Yasui Seiki Co., Ltd.). The coating film was dried by heating at 100 ° C. for 20 minutes in a dryer (“MSO-80TPS” manufactured by Futaba Kagaku Co., Ltd.) to form a resin layer having a thickness of 100 μm. 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 an electrolytic copper foil having a roughened surface with a surface roughness Ra value of 1.5 μm (F2-WS-12, trade name, manufactured by Furukawa Electric Co., Ltd.). Were stacked in such a direction that the roughened surface was on the resin layer side. In this state, an electrolytic copper foil was laminated 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 pressurization type laminator (“V130” manufactured by Nikko Materials Co., Ltd.). . Then, the conductor board | substrate which has the hardened | cured material of the resin layer and the electrolytic copper foil was obtained on the carrier film by heating for 60 minutes at 180 degreeC in dryer (Futaba Kagaku Co., Ltd. "MSO-80TPS"). The cured resin layer was a stretchable resin layer having stretchability showing a recovery rate of 80% or more.

[Roughness formation on the surface of the resin layer]
The carrier film was peeled from a conductive substrate having a stretchable resin layer, which is a cured product of the resin layer, and an electrolytic copper foil, and the uneven transfer film A was superimposed on the exposed resin layer. Using a vacuum pressure laminator (“V130” manufactured by Nichigo-Morton Co., Ltd.), press bonding is performed under the conditions of a pressure of 0.5 MPa, a temperature of 90 ° C., and a pressurization time of 60 seconds to form irregularities on the resin layer surface of the conductive substrate. did.

Example 2-2
(A) Maleic anhydride-modified styrene ethylene butadiene rubber (manufactured by KRATON Co., Ltd., FG1924GT, trade name) 10 g, (B) component as dicyclopentadiene type epoxy resin (DIC Corporation, EPICLON HP7200H, trade name) 2 0.5 g, 1-benzyl-2-methylimidazole (manufactured by Shikoku Kasei Kogyo Co., Ltd., 1B2MZ, trade name) 0.38 g as component (C) (curing accelerator), phenolic antioxidant (manufactured by ADEKA Co., Ltd., AO) -60, trade name) 0.1 g, and phosphite antioxidant (manufactured by ADEKA, 2112, trade name) 0.1 g and toluene 50 g as a solvent were mixed with stirring to obtain a resin varnish. . Using the obtained resin varnish, a laminated film having a resin layer and a conductor substrate were produced in the same manner as in Example 2-1, and irregularities were formed on the resin layer surface of the conductor substrate. The resin layer was a stretchable resin layer having stretchability showing a recovery rate of 80% or more.

Evaluation [heat resistance test]
The laminated film was heated at 180 ° C. for 60 minutes to cure the resin layer, thereby forming a stretchable resin layer. After removing the protective film, the stretchable resin layer and the uneven transfer film A were stacked. Using a vacuum pressure laminator ("V130" manufactured by Nichigo-Morton Co., Ltd.), pressure is 0.5 MPa, temperature is 90 ° C, and pressure is 60 seconds. Unevenness was formed on the surface of the layer. After removing the carrier film, the stretchable resin layer is heated using a nitrogen reflow system (TNV-EN, manufactured by Tamura Seisakusho Co., Ltd.) with the temperature profile of FIG. 3 in accordance with IPC / JEDEC J-STD-020. A heat resistance test was performed. The elongation and tensile modulus of the stretchable resin layer before and after the heat resistance test were measured. The conductor substrate with the unevenness formed on the resin layer was also subjected to the same heat resistance test, and the 90-degree peel strength before and after the heat resistance test was measured.

[Tensile modulus and elongation at break]
A test piece of a strip-shaped stretchable resin layer having a length of 40 mm and a width of 10 mm was prepared. A tensile test of this test piece was performed using an autograph (Shimadzu Corporation “EZ-S”) 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 modulus was obtained from the slope of the stress-strain curve in the range of stress 0.5 to 1.0N. The strain at the time when the test piece broke was recorded as the elongation at break.

[Adhesion (90 degree peel strength)]
The 90 degree peel strength between the copper foil and the stretchable resin layer was measured by a peel test in which the copper foil was peeled from the conductor substrate at a peel angle of 90 degrees.

[Surface roughness and tackiness of stretchable resin layer]
The surface roughness and the tack value of the surface were measured in the same manner as in Study 1 for the stretchable resin layer in which irregularities were formed on the conductor substrate.

  As shown in Table 2, the stretchable resin layers of Example 2-1 and Example 2-2 maintained excellent stretchability and high adhesion to copper foil even after the heat resistance test. Moreover, the tack value of the resin layer was low, and the handleability of the conductor substrate was excellent.

[High temperature long-time standing test]
The laminated film was heated at 180 ° C. for 60 minutes to cure the resin layer and form a stretchable resin layer. After removing the protective film, the stretchable resin layer and the uneven transfer film A were stacked. Using a vacuum pressure laminator ("V130" manufactured by Nichigo-Morton Co., Ltd.), pressure is 0.5 MPa, temperature is 90 ° C, and pressure is 60 seconds. Unevenness was formed on the surface of the layer. After removing the carrier film, the stretchable resin layer is left in a safety oven (SPH (H) -102, manufactured by ESPEC Corporation) in the atmosphere at 160 ° C. for 168 hours for a long period of time. Went. The elongation at break and elastic modulus before and after the high temperature long time standing test were measured under the same conditions as described above. Moreover, the external appearance of the stretchable resin layer after the high-temperature and long-time standing test was visually observed to confirm the presence or absence of discoloration. For Example 2-2, the adhesion was also evaluated.

  As shown in Table 3, the stretchable resin layer of Example 2-2 containing an antioxidant has little change in characteristics even after a high-temperature and long-time standing test at 160 ° C. for 168 hours. Also, no discoloration was observed. Although the stretchable resin layer of Example 2-1 maintained the initial characteristics in the heat resistance test, a change in the characteristics was observed after the more severe high-temperature and long-time standing test. In particular, it can be said that application of an antioxidant is effective in applications requiring high heat resistance.

Study 3
Example 3-1
[Preparation of conductor substrate]
The protective film was removed from the laminated film A of Study 1, and the stretchable resin layer was swollen with a swelling dip securigant P (1000 mL / L, manufactured by Atotech Co., Ltd.) and NaOH (3 g / L) 70 It was immersed in a mixed solution at 0 ° C. for 5 minutes. Next, the stretchable resin layer was immersed in a 70 ° C. mixed solution of concentrate compact CP (640 mL / L, manufactured by Atotech, trade name) and NaOH (40 g / L) as a roughening solution for 10 minutes. Subsequently, the stretchable resin layer was immersed for 5 minutes in a 40 ° C. mixed solution of reduction solution securigant P500 (200 mL / L, manufactured by Atotech, product name) and H ₂ SO ₄ (100 mL / L) as a neutralizing solution. .

  Next, as a pretreatment for electroless plating, the stretchable resin layer was immersed in a cleaner securigant 902 (40 mL / L, manufactured by Atotech Co., Ltd.) as a conditioner solution at 60 ° C. for 5 minutes, and then washed with water. Next, as a pre-dip step, the stretchable resin layer was immersed in a mixed solution of Pre-dip Neo Gantt B (20 mL / L, manufactured by Atotech Co., Ltd.) and sulfuric acid (1 mL / L) at 25 ° C. for 1 minute. Next, as a catalyst application step, an elastic resin layer is applied to a mixed solution of activator Neogant 834 conch (40 mL / L, manufactured by Atotech Co., Ltd.), sodium hydroxide (4 g / L), and boric acid (5 g / L). It was immersed for 5 minutes at 35 ° C. Next, as a reduction process, a stretchable resin layer is applied to a mixed solution of reducer Neogant WA (5 mL / L, manufactured by Atotech, product name) and reducer accelerator 810 mod (100 mL / L, manufactured by Atotech, product name) at 25 ° C. Soaked for 1 minute. Then, as an electroless copper plating process, Basic Solution Print Gantt MSK (80 mL / L, Atotech, product name), Copper Solution Print Gantt MSK (40 mL / L, Atotech, product name), Reducer Cu (14 mL / L) , Atotech Co., Ltd., product name), Stabilizer Print Gantt MSK (3 mL / L, Atotech Co., Ltd., product name) mixed solution is immersed in a stretchable resin layer at 28 ° C. for 15 minutes, and is approximately 0.5 μm thick. A film was formed on the stretchable resin layer. Thereafter, using a dryer (“MSO-80TPS” manufactured by Futaba Kagaku Co., Ltd.) for 15 minutes at 80 ° C., copper plating was further formed by copper sulfate electrolytic plating. Thereafter, annealing treatment was performed at 150 ° C. for 30 minutes to obtain a conductor substrate having a stretchable resin layer and a copper plating film having a thickness of 5 μm formed on the surface thereof. Thereafter, the carrier film was removed from the conductor substrate, and the uneven transfer film A was superimposed on the exposed surface of the resin layer. Using a vacuum pressure laminator (Nichigo-Morton “V130”), the pressure-sensitive adhesive film was exposed under pressure of 0.5 MPa, a temperature of 90 ° C. and a pressurization time of 60 seconds. Unevenness was formed on the surface of the resin layer.

Example 3-2
A laminated film having an uncured resin layer was obtained in the same manner as in Example 1-1 except that the resin varnish A was changed to the resin varnish B of Study 1. After the protective film of the laminated film is peeled off, ultraviolet rays (wavelength 365 nm) are irradiated with an energy amount of 2000 mJ / cm ² by an ultraviolet exposure machine (“ML-320FSAT” manufactured by Mikasa Co., Ltd.) to cure the resin layer of the laminated film. Thus, an elastic resin layer was formed. A copper plating film was formed on the formed stretchable resin layer by the same method as in Example 3-1, and a conductor substrate was obtained on the carrier film. Thereafter, the carrier film was removed from the conductor substrate in the same manner as in Example 3-1, and irregularities were formed on the exposed resin layer surface.

Example 3-3
A laminated film having an uncured resin layer was obtained in the same manner as in Example 1-1 except that the resin varnish A was changed to the resin varnish C of Study 1. Then, the protective film of the laminated film was peeled off, and the resin layer was cured under conditions of 180 ° C. for 1 hour using a dryer (“MSO-80TPS” manufactured by Futaba Kagaku Co., Ltd.) to form a stretchable resin layer. A copper plating film was formed on the formed stretchable resin layer by the same method as in Example 3-1, and a conductor substrate was obtained on the carrier film. Thereafter, the carrier film was removed from the conductor substrate in the same manner as in Example 3-1, and irregularities were formed on the exposed resin layer surface.

Comparative Example 3-1
A laminated film having an uncured resin layer was obtained in the same manner as in Example 1-1 except that the resin varnish A was changed to the resin varnish D of Study 1. Then, the protective film of the laminated film was peeled off, and the resin layer was cured at 180 ° C. for 1 hour using a dryer (“MSO-80TPS” manufactured by Futaba Kagaku Co., Ltd.). A copper plating film was formed on the cured resin layer in the same manner as in Example 3-1, and a conductor substrate was obtained on the carrier film. Thereafter, the carrier film was removed from the conductor substrate in the same manner as in Example 3-1, and irregularities were formed on the exposed resin layer surface.

[Surface roughness and tackiness of resin layer]
The surface roughness and the tack value of the surface were measured in the same manner as in Study 1 for the resin layer on which the unevenness was formed on the conductor substrate.

[Production and evaluation of wiring board]
As shown in FIG. 2, a test wiring board 1 having a resin layer 3 and a conductor plating film having a corrugated pattern formed on the resin layer 3 as a conductor layer 5 was produced. First, an etching resist (manufactured by Hitachi Chemical Co., Ltd., Photec RY-5325, product name) is attached to the conductive layer of each conductive substrate having irregularities formed on the resin layer surface with a roll laminator, and a corrugated pattern is formed there. The formed photo tool was brought into close contact. 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 the conductor plating film 5 on the resin layer 3 in which the wiring width is 50 μm and the wavy wiring pattern meandering along the predetermined direction X is formed. Obtained.

  The obtained wiring board was pulled and deformed in the X direction to a strain of 10%, and the resin layer and the corrugated wiring pattern were observed when the wiring board was restored. The case where the resin layer and the wiring pattern were not broken at the time of extension was designated as “A”, and the case where the breakage occurred was designated as “C”.

  Table 4 shows the evaluation results of Examples 3-1 to 3-3 and Comparative Example 3-1. In the wiring board having the corrugated wiring pattern formed by the conductor substrates of Examples 3-1 to 3-3, the stretchable resin layer does not break even when stretched by 10%, and the appearance of the corrugated wiring pattern is also good. I found that there was no problem. On the other hand, in Comparative Example 3-1, since the resin layer did not have elasticity, it was found that the resin layer was broken before stretching by 10%, and the wiring was also broken at the same time.

Study 4
[Example 4-1]
Similar to the uneven transfer film A, except that the electrolytic copper foil used to prepare the uneven transfer film was “F0-WS-18” (Furukawa Electric Co., Ltd., surface roughness Ra value of the roughened surface: 0.2 μm). Thus, an uneven transfer film B (surface roughness Ra value: 0.2 μm) was produced. Except having changed the uneven | corrugated transfer film A into the uneven | corrugated transfer film B, it carried out similarly to Example 2-1, and obtained the conductor substrate by which the unevenness | corrugation was formed in the resin layer surface.

[Example 4-2]
A conductor substrate having unevenness formed on the surface of the resin layer was obtained in the same manner as in Example 2-1, except that the temperature of the vacuum pressurizing laminator when transferring the unevenness after overlapping the unevenness transfer film was set to 70 ° C.

[Comparative Example 4-1]
A conductor substrate was obtained in the same manner as in Example 2-1, except that the uneven transfer process to the resin layer surface was not performed.

[Comparative Example 4-2]
A conductor substrate having unevenness formed on the surface of the resin layer was obtained in the same manner as in Example 2-1, except that the temperature of the vacuum pressurizing laminator when transferring the unevenness after overlapping the unevenness transfer film was set to 60 ° C.

[Surface roughness and tackiness of resin layer]
For the resin layer exposed on the conductor substrate, the surface roughness and the surface tack value were measured in the same manner as in Study 1.

  Table 5 shows the evaluation results of Examples 4-1 to 4-2 and Comparative Examples 4-1 to 4-2. In the surface roughness and tack value of the resin layer of the conductor substrate of Examples 4-1 to 4-2, it was found that the surface roughness was large and the tack value was low due to the effect of the formed uneven pattern. On the other hand, in Comparative Example 4-1, since the resin layer did not have an uneven | corrugated pattern, it turned out that the surface is flat and a tack value becomes high. In Comparative Example 4-2, it was found that the surface roughness was small and the tack value was high.

  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 ... Resin layer, 5 ... Conductor layer (conductor foil or conductor plating film).

Claims (20)

An elastic resin layer;
A conductive foil provided on one main surface of the stretchable resin layer,
The conductor board whose surface roughness Ra value of the other main surface of the said elastic resin layer is 0.1 micrometer or more.   The conductor board | substrate of Claim 1 whose elastic modulus of the said conductor foil is 40-300GPa. An elastic resin layer;
A conductive plating film provided on one main surface of the stretchable resin layer,
The conductor board whose surface roughness Ra value of the other main surface of the said elastic resin layer is 0.1 micrometer or more.   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 stretchable resin layer contains (A) a rubber component,
The rubber component 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 chlorinated butyl rubber. The conductive substrate according to any one of claims 1 to 4, comprising at least one rubber selected from the group consisting of:   The conductive substrate according to any one of claims 1 to 5, wherein the stretchable resin layer includes a cured product of a resin composition containing (A) a rubber component.   The conductive substrate according to claim 6, wherein the rubber component includes a rubber having a crosslinking group.   The conductor substrate according to claim 7, wherein the crosslinking group is at least one of an acid anhydride group or a carboxyl group.   The conductor substrate according to any one of claims 6 to 8, wherein the resin composition further contains (B) a crosslinking component.   (B) The crosslinking component is at least one selected from the group consisting of (meth) acryloyl groups, vinyl groups, epoxy groups, styryl groups, amino groups, isocyanurate groups, ureido groups, cyanate groups, isocyanate groups, and mercapto groups. The conductor board | substrate of Claim 9 containing the compound which has the reactive group of.   The conductor substrate according to any one of claims 6 to 10, wherein the resin composition further contains at least one of (C) a curing agent or a curing accelerator.   (A) The conductor substrate as described in any one of Claims 5-11 whose content of a rubber component is 30-100 mass% with respect to 100 mass% of the said stretchable resin layers.   The conductive substrate according to any one of claims 1 to 12, wherein the stretchable resin layer further contains an antioxidant.   A wiring board comprising the conductive board according to claim 1, 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 14 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 conductor foil or a conductor plating film provided on one main surface of the stretchable resin layer;
Forming a concavity and convexity on the other principal surface of the stretchable resin layer so that the surface roughness Ra value is 0.1 μm or more. 14. The conductor according to claim 1, A method for manufacturing a substrate.   The manufacturing method of a wiring board including the process of forming a wiring pattern in the said conductor foil or the said conductor plating film of the conductor board as described in any one of Claims 1-13.