Resin wiring board and stretchable device

Abstract

The present invention provides a resin wiring substrate and a stretchable device provided with the resin wiring substrate, the resin wiring substrate having a stretchable resin base material (11) and a wiring pattern (21), the wiring pattern (21) including a metal wiring (22) formed of a metal film having a particle diameter of 0.5 [mu] m to 2.0 [mu] m, at least a part of the metal wiring (22) is covered by a stretchable resin base material (11) and a resin covering layer (31) formed by a stretchable resin in a cross-sectional view, and the resin wiring substrate has the metal wiring which is not easily peeled off from the stretchable resin base material. The metal wiring (22) may have, in a cross-sectional view, an embedded portion (22a) formed along the inside of a recessed portion (11b) formed in the first surface (11a) of the stretchable resin substrate (11), and an exposed portion (22b) exposed from the first surface (11a).

Description

Technical Field

[0001] This invention relates to resin wiring boards and stretchable devices.

[0002] This application claims priority based on Japanese Patent Application No. 2023-054530 filed on March 30, 2023, and incorporates the contents of that application. Background Technology

[0003] Wearable devices are gaining attention in a wide range of fields, including sports science and healthcare. Ideally, wearable devices should offer a comfortable, unrestricted fit. Therefore, it is desirable for them to possess the characteristic of being freely stretchable (extensible) to fit the wearer. In this specification, devices possessing this characteristic are referred to as stretchable devices, and their applications are not limited to wearable devices.

[0004] Patent Document 1 discloses a flexible wiring substrate comprising a conductor substrate having a flexible resin substrate having a tensile modulus of elasticity of 10 to 50 MPa, and a conductor layer disposed on the flexible resin substrate, wherein the conductor layer forms a wiring pattern. Furthermore, Patent Document 1 also discloses that the flexible resin substrate comprises a cured product of a curable resin composition containing rubber components and fillers.

[0005] Patent Document 2 describes a wiring sheet formed by providing an electrical lead pattern including a terminal portion and a conductive line pattern on a stretchable substrate. Furthermore, Patent Document 2 also describes a wiring sheet formed by covering and fixing the portion where at least the end of the electrical lead pattern contacts the end of the line pattern with resin.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 2019-197867 (A)

[0009] Patent Document 2: Japanese Patent Application Publication No. 2022-19237(A) Summary of the Invention

[0010] (a) Technical problems to be solved

[0011] However, for conventional resin wiring substrates with metal wiring formed on a stretchable resin substrate, the problem arises that the metal wiring is prone to peeling off from the stretchable resin substrate.

[0012] The present invention was implemented in view of the above-mentioned technical problems, and its object is to provide a resin wiring substrate having metal wiring with a resin substrate that is not easily peeled off, and a stretchable device having the resin wiring substrate.

[0013] (II) Technical Solution

[0014] To address the aforementioned technical issues, the following methods are provided.

[0015] [1] A resin wiring substrate having a stretchable resin substrate and a wiring pattern.

[0016] The wiring pattern comprises metal wiring formed from metal films with a particle size of 0.5 μm to 2.0 μm.

[0017] At least a portion of the metal wiring is covered in a cross-sectional view by the stretchable resin substrate and a resin coating layer formed of the stretchable resin.

[0018] [2] According to the resin wiring substrate of [1], the metal wiring has an embedded portion formed along a recess formed in a first surface of the elastic resin substrate in a cross-sectional view, and an exposed portion exposed from the first surface.

[0019] [3] According to the resin wiring substrate of [2], the exposed portion is formed on the same plane as the first surface.

[0020] [4] According to the resin wiring substrate of [2] or [3], at least a portion of the exposed portion is covered by a resin covering layer formed of a stretchable resin.

[0021] [5] The resin wiring substrate according to any one of [2] to [4], wherein the wiring pattern has stretchable linear wiring disposed on the first surface.

[0022] Only a portion of the metal wiring is covered by the elastic resin substrate and the resin coating in the cross-sectional view.

[0023] One or both ends of the flexible wiring are formed in such a way that they are connected to the exposed portion of the metal wiring.

[0024] [6] The resin wiring substrate according to any one of [1] to [5], wherein the elongation at break of the elastic resin substrate is 50% or more.

[0025] [7] The resin wiring substrate according to any one of [1] to [6], wherein the heat resistance temperature of the metal wiring is 200°C or higher.

[0026] [8] According to the resin wiring substrate of [1], wherein the elongation at break of the resin covering layer is 50% or more.

[0027] [9] A scalable device comprising a resin wiring board as described in any one of [1] to [8].

[0028]

[10] A stretchable device comprising a resin wiring substrate as described in any one of [2] to [8], wherein only a portion of the metal wiring is covered in a cross-sectional view by the stretchable resin substrate and the resin covering layer.

[0029] The exposed portion of the metal wiring is arranged facing the terminals of the electronic device.

[0030] The exposed portion and the terminal are electrically connected by solder.

[0031] (III) Beneficial Effects

[0032] The resin wiring substrate of the present invention has a stretchable resin substrate and a wiring pattern. The wiring pattern includes metal wiring formed from a metal film with a particle size of 0.5 μm to 2.0 μm. At least a portion of the metal wiring is covered by the stretchable resin substrate and a resin capping layer formed from the stretchable resin in a cross-sectional view. Therefore, compared to, for example, a case without a resin capping layer, the metal wiring of the resin wiring substrate of the present invention is less likely to peel off from the stretchable resin substrate. Furthermore, for the resin wiring substrate of the present invention, since the resin capping layer is formed from a stretchable resin, the resin capping layer can follow the stretching and contraction of the stretchable resin substrate, and the resin capping layer has good adhesion to the stretchable resin substrate. In summary, even if the stretchable resin substrate stretches and contracts, the metal wiring of the resin wiring substrate of the present invention is less likely to peel off from the stretchable resin substrate.

[0033] Furthermore, since the flexible device of the present invention has the resin wiring substrate of the present invention, the metal wiring is not easily peeled off from the flexible resin substrate of the resin wiring substrate, resulting in excellent reliability. Attached Figure Description

[0034] Figure 1 This is a plan view illustrating an example of a scalable device of the present invention that includes a resin wiring board of the present invention.

[0035] Figure 2A To be Figure 1 The telescopic device shown along Figure 1 The cross-sectional view when the A-A' line is cut.

[0036] Figure 2B To be Figure 1 The telescopic device shown along Figure 1 The cross-sectional view when the B-B' line is cut.

[0037] Figure 2C To be Figure 1 The telescopic device shown along Figure 1 The cross-sectional view when the C-C' line is cut.

[0038] Figure 3A For illustrative purposes Figure 1 A process diagram illustrating an example of a method for manufacturing a scalable device.

[0039] Figure 3B For illustrative purposes Figure 1 A process diagram illustrating an example of a method for manufacturing a scalable device.

[0040] Figure 3C For illustrative purposes Figure 1 A process diagram illustrating an example of a method for manufacturing a scalable device.

[0041] Figure 3D For illustrative purposes Figure 1 A process diagram illustrating an example of a method for manufacturing a scalable device.

[0042] Figure 3E For illustrative purposes Figure 1 A process diagram illustrating an example of a method for manufacturing a scalable device.

[0043] Figure 3F For illustrative purposes Figure 1 A process diagram illustrating an example of a method for manufacturing a scalable device.

[0044] Figure 3G For illustrative purposes Figure 1 A process diagram illustrating an example of a method for manufacturing a scalable device.

[0045] Figure 3H For illustrative purposes Figure 1 A process diagram illustrating an example of a method for manufacturing a scalable device. Detailed Implementation

[0046] The resin wiring board and scalable device of this embodiment will now be described in detail with appropriate reference to the accompanying drawings. In the drawings used in the following description, characteristic features are sometimes shown enlarged to facilitate a better understanding of the features of the invention. Therefore, the dimensional ratios of the constituent elements are not always identical to the actual figures. The materials, dimensions, etc., illustrated in the following description are merely examples, and the invention is not limited thereto; appropriate modifications and implementations can be made without altering its essence.

[0047] [Flexible equipment]

[0048] Figure 1 This is a plan view illustrating an example of a scalable device of the present invention that includes a resin wiring board of the present invention. Figure 2A To be Figure 1 The telescopic device shown along Figure 1 The cross-sectional view when the A-A' line is cut. Figure 2B To be Figure 1 The telescopic device shown along Figure 1 The cross-sectional view when the B-B' line is cut. Figure 2C To be Figure 1 The telescopic device shown along Figure 1 The cross-sectional view when the C-C' line is cut.

[0049] Figure 1 , Figures 2A to 2C The scalable device of this embodiment shown includes a resin wiring substrate 1. The resin wiring substrate 1 has a scalable resin substrate 11 and a wiring pattern 21. The resin wiring substrate 1 and the scalable resin substrate 11 of this embodiment have a strip-like shape. Figure 1 and Figure 2C As shown, two electronic devices 41 are disposed on the first surface 11a of the elastic resin substrate 11 disposed approximately at the center of the long side of the resin wiring board 1.

[0050] (Stretchable resin substrate 11)

[0051] The stretchable resin substrate 11 is in sheet form, and its elongation at break is preferably 50% or more, more preferably 200% or more. When the stretchable resin substrate 11 is a stretchable resin substrate with good stretchability and an elongation at break of 50% or more, it becomes a resin wiring board 1 suitable for use in various stretchable devices such as wearable devices. The elongation at break of the stretchable resin substrate 11 can be varied by appropriately selecting the material of the stretchable resin substrate 11. Furthermore, the elongation at break of the stretchable resin substrate 11 is preferably 4000% or less. This is because it is easy to make a resin wiring board 1 with sufficient strength and durability.

[0052] In this specification, "elongation at break" is defined as {(length at break - length before stretching) / length before stretching} × 100 (%). Elongation at break can be measured in a specified direction.

[0053] In this specification, "the elongation at break of the elastic resin substrate 11 is 50% or more" refers to the elongation at break in the direction of maximum elongation at break. Furthermore, as long as there is no anisotropy in the elongation at break, the elongation at break is equal in any direction. Additionally, if the anisotropy of the elongation at break is small, the elongation at break will be a similar value in any direction.

[0054] (Method for determining the elongation at break of the elastic resin substrate 11)

[0055] Six strip-shaped test specimens, each 10 mm wide and 30 mm long, were cut from the elastic resin substrate 11. For each test specimen, the elongation at break was calculated using the method shown below, and the average value was taken as the elongation at break.

[0056] A metal substrate is clamped between the upper and lower clamping parts of the testing instrument, and the test specimen is fixed to the metal substrate with double-sided tape so that the measurement area is 10 mm wide and 10 mm long. Then, the test specimen is stretched at a tensile speed of 10 mm / min using a tensile testing machine (e.g., AUTOGRAPHAGS-5kNX, manufactured by Shimadzu Corporation). Next, the length of the test specimen at fracture is measured, and the length before stretching (10 mm) is subtracted from this length to calculate the elongation at fracture (length at fracture - length before stretching) of each test specimen. The average value of these values ​​is taken as the elongation at fracture, and the elongation at fracture is calculated according to the above definition.

[0057] As the stretchable resin substrate 11, a substrate containing a known stretchable resin can be used. Examples of stretchable resins include, for example, epoxy resins, urethane resins, urea resins, polyurethane urea resins, methacrylic resins, polyacrylic resins, silicone resins, diene resins, polyester resins, polyether resins, polyamide resins, and polystyrene resins. When the stretchable resin contained in the stretchable resin substrate 11 is a urethane resin, it has a high elongation at break, making it a stretchable resin substrate with excellent flexibility, and is therefore preferred.

[0058] The stretchable resin substrate 11 preferably does not contain a curing agent. This is because the presence of a curing agent will not promote the deterioration of the stretchable resin substrate 11 over time, resulting in a stretchable resin substrate 11 with good durability.

[0059] In this embodiment, the stretchable resin substrate 11 in the resin wiring board 1 is preferably a substrate formed by solidifying a resin composition containing resin component (P) and solvent.

[0060] The resin component (P) contained in the resin composition preferably has, for example, a urethane bond, and any one or more groups represented by the following general formula (11), (21) or (31) from a reversible addition-fragmentation chain transfer polymer (sometimes abbreviated as "RAFT agent" in this specification).

[0061] [Chemical Formula 1]

[0062]

[0063] (In equation (11), Z) 1 The alkyl group is an alkyl group, wherein one or more hydrogen atoms are optionally substituted with a cyano, carboxyl, or methoxycarbonyl group, and the two or more substituents are optionally the same or different from each other. In formula (21), Z 2 It is an alkyl group, Z 3 It is an aryl group. In formula (31), R 4 It is a hydrogen atom or a halogen atom. The * in formulas (11), (21), or (31) represents the bond between the group represented by formula (11), (21), or (31) and the bonding object.

[0064] The resin component (P) contained in the resin composition may have urethane bonds, siloxane bonds, and any one or more groups represented by the above general formulas (11), (21), or (31) from the RAFT agent. When the resin component (P) has siloxane bonds, the stretchable resin substrate formed by solidifying the resin composition containing the resin component (P) has moderate water repellency. As a result, the urethane bonds in the stretchable resin substrate are not easily hydrolyzed, resulting in a stretchable resin substrate with excellent durability, where degradation over time due to hydrolysis is suppressed.

[0065] When resin component (P) has siloxane bonds, there is no particular limitation on the ratio of the number of urethane bonds to the number of siloxane bonds in resin component (P), and it can be appropriately determined according to the application of the elastic resin substrate, the required durability, elongation at break, and other characteristics.

[0066] The resin component (P) can be prepared, for example, by the method shown below.

[0067] That is, it can be prepared by the following method: using a polymerization initiator and a RAFT agent as the source of groups represented by general formula (11), (21) or (31), a resin (a) having structural units from compounds having urethane bonds and polymerizable unsaturated bonds, a resin (b) having structural units from compounds having siloxane bonds and polymerizable unsaturated bonds as needed, and polymerizable components other than resin (a) and resin (b) as needed, under known conditions, a method of reversible addition-fragmentation chain transfer polymerization (RAFT polymerization).

[0068] In the above-described method for preparing resin component (P), since a RAFT agent is used to perform RAFT polymerization on resin (a), resin (b) as needed, and polymerizable components other than resin (a) and resin (b) as needed, gelation of the resin component during the polymerization process that forms a cross-linked structure can be prevented. Furthermore, in the above-described preparation method, since resin (a), resin (b) as needed, and polymerizable components other than resin (a) and resin (b) as needed are subjected to RAFT polymerization, resin component (P) with the target degree of polymerization and cross-linking state can be easily prepared.

[0069] The resin (a) used as the resin component (P) is an oligomer having structural units derived from compounds having urethane bonds and polymerizable unsaturated bonds. Examples of resins (a) include, for instance, resins having structural units derived from compounds having urethane bonds and (meth)acryloyl groups. Resin (a) preferably has structural units derived from urethane (meth)acrylates.

[0070] In this specification, "(meth)acrylate" is a concept that includes both "acrylate" and "methacrylate". Similarly, similar terms include, for example, "(meth)acryloyl" which includes both "acryloyl" and "methacryloyl".

[0071] The resin (b) used as the resin component (P) is an oligomer having structural units derived from compounds having siloxane bonds and polymerizable unsaturated bonds. Examples of compounds having siloxane bonds and polymerizable unsaturated bonds include, for example, various known organosilicon resins having (meth)acryloyl groups as polymerizable unsaturated groups. As resin (b), for example, resins having structural units derived from modified polydialkylsiloxanes having (meth)acryloyl groups bonded to one or both ends of polydialkylsiloxanes such as polydimethylsiloxane can be used.

[0072] In addition to resins (a) and (b), polymerizable components used as resin component (P) can be compounds with polymerizable unsaturated bonds, and alkyl (meth)acrylates are preferred. Specifically, examples of alkyl (meth)acrylates include methyl (meth)acrylate, ethyl (meth)acrylate, allyl (meth)acrylate, propyl (meth)acrylate, and isopropyl (meth)acrylate. Only one or more of these compounds with polymerizable unsaturated bonds may be used.

[0073] There are no particular restrictions on the proportions of resin (a), resin (b), and polymeric components other than resin (a) and resin (b) used as resin component (P), and these proportions can be appropriately determined based on the intended use of the elastic resin substrate, the required strength, elongation at break, and other characteristics.

[0074] Specifically, a higher content of resin (a) results in a resin component (P) with more urethane bonds, leading to a stretchable resin substrate with excellent flexibility. Furthermore, a sufficiently high content of resin (b) results in a resin component (P) with more siloxane bonds. The urethane bonds in resin component (P) are less prone to hydrolysis, resulting in a stretchable resin substrate with excellent durability. Moreover, by ensuring a sufficiently high content of polymeric components other than resin (a) and resin (b), it is easy to obtain a stretchable resin substrate with properties suitable for its intended use and required strength.

[0075] As a polymerization initiator used in the manufacture of resin component (P), one or more of the known polymerization initiators such as persulfate, hydrogen peroxide, azo compounds, and organic peroxides can be used, with azo compounds being preferred.

[0076] The solvent contained in the resin composition only needs to be able to disperse or dissolve the resin component (P). Specifically, N,N-dimethylacetamide (DMAc), methyl ethyl ketone (MEK), N,N-dimethylformamide (DMF), diethylene glycol monobutyl ether, diethylene glycol monobutyl ether acetate (BCA), diethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol butyl ether (BC), ethyl cyanoacrylate (ECA), α-terpineol, acetone, ethanol, methanol, ethyl lactate, butyl lactate, toluene, isopropanol, isobutanol, ethyl acetate, butyl acetate, etc., can be used as the solvent. Only one solvent selected from the above-mentioned solvents can be used, or two or more solvents can be used.

[0077] (Wiring pattern 21)

[0078] The wiring pattern 21 is composed of electrically connected metal wires 22, end wires 23, and flexible wires 24. The wiring pattern 21 is a linear pattern with a uniform width in a top view. The planar shape of the wiring pattern 21 is not particularly limited and can be appropriately determined according to the application of the resin wiring substrate 1. Preferably, the planar shape of the wiring pattern 21 is one that is not easily broken or peeled off even if the flexible resin substrate 11 deforms, for example, such as... Figure 1 As shown, the shape can be configured as a curve formed by continuous arcs with a specified radius of curvature. Furthermore, the number of wiring patterns 21 can be appropriately determined according to the intended use of the resin wiring substrate 1.

[0079] [Metallic wiring 22]

[0080] like Figure 1 and Figures 2A to 2C As shown, the metal wiring 22 is disposed at both ends and the center of the strip-shaped stretchable resin substrate 11 in a top view.

[0081] Two metal wires 22 are arranged at both ends, with their outer ends extending outward from the edge of the stretchable resin substrate 11 to form end wires 23. In addition, the inner ends of the metal wires 22 arranged at both ends are electrically connected to the outer ends 24a of the stretchable wires 24.

[0082] Furthermore, the outer ends of two arranged metal wires 22 are electrically connected to the inner ends of the retractable wire 24 at one end and the other end of the central portion, respectively. Additionally, the inner ends of the metal wires 22 arranged in the central portion are electrically connected to the electronic device 41 via solder 42.

[0083] The metal wiring 22 is made of metal and has a roughly rectangular cross-sectional shape. All metal wirings 22 are as follows... Figure 1 As shown in the top view, it is a line; a portion of the area in the top view is as follows. Figure 2B As shown in the cross-sectional view, the metal wiring 22 is covered by the stretchable resin substrate 11 and the resin coating layer 31. While not particularly limited, when the overall area of ​​the metal wiring 22 in the top view is set to 100%, the area of ​​the metal wiring 22 covered by the stretchable resin substrate 11 and the resin coating layer 31 can be less than 100%, less than 90%, or less than 80%. Furthermore, the area of ​​the metal wiring 22 covered by the stretchable resin substrate 11 and the resin coating layer 31 can be more than 1%, more than 10%, or more than 20%. Furthermore, it is preferable that all metal wiring 22 is as shown... Figures 2A to 2C The diagram shows a recessed portion 22a and an exposed portion 22b.

[0084] In cross-sectional view, the embedded portion 22a is formed along the interior of the recess 11b formed on the first surface 11a of the elastic resin substrate 11. Therefore, the exterior of the embedded portion 22a is arranged in contact with the elastic resin substrate 11. Furthermore, by embedding the embedded portion 22a within the recess 22b of the elastic resin substrate 11, the embedded metal wiring 22 is retained.

[0085] The first surface 11a of the self-stretching resin substrate 11 is exposed at the exposed portion 22b. In this embodiment, as... Figures 2A to 2CAs shown, the exposed portion 22b is formed on a plane that is substantially the same as the first surface 11a of the stretchable resin substrate 11. Therefore, compared to the case where the exposed portion 22b protrudes from the first surface 11a of the stretchable resin substrate 11, the proportion of the outer area of ​​the embedded portion 22a is relatively larger. As a result, the contact area between the metal wiring 22 and the stretchable resin substrate 11 is large, and the adhesion of the metal wiring 22 to the stretchable resin substrate 11 becomes better. Furthermore, since the exposed portion 22b is formed on a plane that is substantially the same as the first surface 11a of the stretchable resin substrate 11, the metal wiring 22 is completely filled into the recess 22b in the cross-sectional view, and the metal wiring 22 can be more effectively held by the recess 22b. Therefore, the metal wiring 22 is less likely to peel off from the stretchable resin substrate 11 even if the stretchable resin substrate 11 expands or contracts.

[0086] Furthermore, when the metal wiring 22 is electrically connected to the flexible wiring 24 or the electronic device 41 using known methods, the exposed portion 22b can function as a solder pad. In this embodiment, since the exposed portion 22b is formed on a plane substantially the same as the first surface 11a of the flexible resin substrate 11, compared to cases where the exposed portion 22b protrudes from the first surface 11a of the flexible resin substrate 11, or where the exposed portion 22b is formed closer to the bottom surface of the recess 11b than the first surface 11a of the flexible resin substrate 11, the metal wiring 22 can be easily electrically connected to the flexible wiring 24, or the metal wiring 22 to the terminal 41a of the electronic device 41. Therefore, when the exposed portion 22b is formed on a plane substantially the same as the first surface 11a of the flexible resin substrate 11, it can more preferably be used as a solder pad.

[0087] Furthermore, since the exposed portion 22b is formed on a plane that is substantially the same as the first surface 11a of the stretchable resin substrate 11, the metal wiring 22 having the embedded portion 22a and the exposed portion 22b can be easily manufactured using the manufacturing method described later. This results in better productivity compared to cases where, for example, the exposed portion 22b protrudes from the first surface 11a of the stretchable resin substrate 11, or the exposed portion 22b is formed at a position closer to the bottom surface of the recess 11b than the first surface 11a of the stretchable resin substrate 11.

[0088] [End Wiring 23]

[0089] The end wirings 23 are formed by extending from the metal wirings 22 disposed at both ends of the elastic resin substrate 11. Therefore, the end wirings 23 are made of the same metal as the metal wirings 22 and have the same generally rectangular cross-sectional shape as the metal wirings 22. Furthermore, as... Figure 1 and Figure 2CAs shown, the end wiring 23 is positioned in a top view where it does not overlap with the stretchable resin substrate 11. Therefore, the end wiring 23 is exposed and not connected to the stretchable resin substrate 11. The length of the end wiring 23 is not particularly limited; for example, it is preferably set to a length suitable for electrically connecting the end wiring 23 to wiring in other devices.

[0090] The end wiring 23 is exposed and not in contact with the stretchable resin substrate 11. Therefore, the end wiring 23 can be easily electrically connected to other devices using known methods. Furthermore, since the end wiring 23 is positioned in a top view where it does not overlap with the stretchable resin substrate 11, even if the wiring electrically connected to other devices and the end wiring 23 are heated and joined, the effects of heating on the stretchable resin substrate 11 can be suppressed. The resin wiring board 1 of this embodiment can also be a resin wiring board on which the wiring electrically connected to other devices is joined.

[0091] In this embodiment, the metal wiring 22 and the end wiring 23 are formed from a metal film with a particle size of 0.5 μm to 2.0 μm. Therefore, the metal wiring 22 and the end wiring 23 can be easily manufactured using the electroplating method described later. Furthermore, since the metal wiring 22 and the end wiring 23 are formed from a metal film with a particle size of 0.5 μm to 2.0 μm, the metal wiring 22 and the end wiring 23 can be formed with sufficient thickness using the electroplating method described later.

[0092] The particle size of the metal film forming the metal wiring 22 and the end wiring 23 can be determined, for example, by the method shown below. It can be determined by observing the surface of the metal film using a scanning electron microscope (SEM) (e.g., 10,000x magnification), measuring the particle size of 100 particles in the field of view, and calculating the average value.

[0093] Furthermore, the metal wiring 22 and the end wiring 23 are preferably formed of a metal film with a grain size of 0.3 μm to 1.8 μm, and more preferably of a metal film with a grain size of 0.7 μm to 1.5 μm. This is because the metal wiring 22 and the end wiring 23 can be easily formed using the electroplating method described later.

[0094] The grain size of the metal film forming the metal wiring 22 and the end wiring 23 can be determined, for example, by the method shown below. It can be determined by observing the surface of the metal film using a transmission electron microscope (TEM) (e.g., 10,000x magnification), measuring the grain size of 100 particles in the field of view, and calculating the average value.

[0095] In this embodiment, "formed of metal" for metal wiring 22 and end wiring 23 means that metal wiring 22 and end wiring 23 contain 90% by mass or more of a metal component. For example, when the metal is copper, metal wiring 22 and end wiring 23 are wiring formed of copper with a purity of 90% by mass or more, or wiring formed of copper with a purity of 96% by mass or more, or wiring formed of copper with a purity of 97% by mass or more.

[0096] The metal wiring 22 and the end wiring 23 are preferably formed of a metal with a heat resistance temperature of 220°C or higher, and more preferably of a metal with a heat resistance temperature of 500°C or higher. Examples of metal materials with a heat resistance temperature of 220°C or higher include: copper (heat resistance temperature 1085°C), silver (heat resistance temperature 962°C), gold (heat resistance temperature 1064°C), palladium (heat resistance temperature 1555°C), tin (heat resistance temperature 232°C), nickel (heat resistance temperature 1453°C), etc. Without particular limitation, the metal wiring 22 and the end wiring 23 may be formed of a metal with a heat resistance temperature of 2300°C or lower.

[0097] Since it can be easily manufactured using the electroplating method described later, has high heat resistance, and excellent conductivity, the metal wiring 22 and the end wiring 23 are preferably made of copper.

[0098] In this specification, "heat resistance temperature" refers to the temperature at which the discoloration or deformation of a metallic material is observed due to heating.

[0099] If the heat resistance temperature of the metal wiring 22 is above 220°C, there are more options for the method of forming an electrical connection between the exposed portion 22b of the metal wiring 22 and the flexible wiring 24 or the electronic device 41.

[0100] Specifically, when the heat resistance temperature of the metal wiring 22 is 220°C or higher, methods for forming an electrical connection between the flexible wiring 24 or the electronic device 41 and the exposed portion 22b of the metal wiring 22 can include spot welding or other methods using molten low-melting-point metals; and bonding methods using adhesives such as conductive adhesives or anisotropic adhesives. Spot welding is preferred because it allows for easy and secure electrical connection between the exposed portion 22b of the metal wiring 22 and the flexible wiring 24 or the electronic device 41.

[0101] Furthermore, if the heat resistance temperature of the end wiring 23 is 220°C or higher, then when the resin wiring board 1 is electrically connected to other devices, there are more options for forming an electrical connection between the wiring that is electrically connected to other devices and the end wiring 23.

[0102] Specifically, when the heat resistance temperature of the end wiring 23 is 220°C or higher, the following methods can be used to form an electrical connection between the wiring that is electrically connected to other devices and the end wiring 23: heating the wiring that is electrically connected to other devices and the end wiring 23 to bond them together; or using adhesives such as conductive adhesives or anisotropic adhesives to bond them together. Among these, the method of heating the wiring that is electrically connected to other devices and the end wiring 23 to bond them together allows for easy and secure electrical connection of the resin wiring board 1 to other devices, and is therefore preferred.

[0103] [Flexible wiring 24]

[0104] like Figure 1 and Figure 2C As shown, the stretchable wiring 24 is a stretchable linear wiring disposed on the first surface 11a of the stretchable resin substrate 11. The stretchable wiring 24 has a generally rectangular cross-sectional shape. Figure 1 and Figure 2C As shown, the two ends 24a of the flexible wiring 24 are formed to connect with the exposed portion 22b of the metal wiring 22. Thus, the flexible wiring 24 is electrically connected to the metal wiring 22.

[0105] As a flexible wiring 24, a wiring containing metal powder and a known flexible resin can be used.

[0106] The metal powder contained in the flexible wiring 24 is not particularly limited, and known metal powders can be used. Preferably, the metal powder contains flake-shaped (thin-flake) powder. This is because when the metal powder contains flake-shaped powder, by making the flake-shaped powder have upper and lower surfaces that expand in the surface direction, the proportion of surface contact between the metal powders becomes higher, and high conductivity (low resistivity) can be obtained.

[0107] In this specification, "flake-shaped powder" refers to powder (metal powder) with a thickness of 1 / 10 or less relative to its maximum particle size. The maximum particle size of flake-shaped powder is defined as follows: Although the length of each flake-shaped powder varies from end to end in its top view depending on the direction, the longest of these lengths is taken as the maximum particle size. The maximum particle size can be determined by methods such as optical microscopy observation, scanning electron microscopy (SEM) observation (e.g., 5000x magnification).

[0108] Examples of metal powders used in the flexible wiring 24 include silver (Ag) powder, carbon (C), copper (Cu) powder, palladium (Pd) powder, gold (Au) powder, and platinum (Pt) powder. Since the flexible wiring 24 will have low resistance and excellent conductivity, silver powder or an alloy powder with silver as the main component is preferred as the metal powder.

[0109] In this specification, "alloy powder with silver as the main component" means that the alloy powder contains more than 50% by mass of silver. Preferably, the alloy powder with silver as the main component contains more than 70% by mass of silver, more preferably more than 80% by mass of silver, and even more preferably more than 90% by mass of silver.

[0110] In addition, silver powder can also be used to coat silver with copper powder, which is silver on the surface and made of metals other than silver inside.

[0111] As a metal powder, properly manufactured metal powder or commercially available products can be used.

[0112] Methods for manufacturing granular silver powder include, for example, adding an aqueous solution containing a reducing agent to an aqueous reaction system containing silver ions, thereby reducing and precipitating silver particles.

[0113] Furthermore, flake-shaped metal powder can be manufactured, for example, by forming a thin film of the desired metal and then micronizing the film. Because the flake-shaped powder is obtained by micronizing the film, the individual metal flakes formed are also flat. The thickness of the flake-shaped powder relative to its maximum particle size (i.e., the degree of flatness) can be adjusted by modifying the thickness of the film used as the material and the degree of micronization.

[0114] The stretchable resin included in the stretchable wiring 24 can be the same as the stretchable resin that can be used in the stretchable resin substrate 11. The stretchable resin included in the stretchable wiring 24 can be the same as or different from the stretchable resin that can be used in the stretchable resin substrate 11, but the same is preferred. This is because it is easy to create a stretchable wiring 24 that has good adhesion to the stretchable resin substrate 11.

[0115] The content of the stretchable wiring 24 containing the stretchable resin is preferably in the range of 8% to 20% by mass, more preferably in the range of 10% to 18% by mass. If the content of the stretchable wiring 24 containing the stretchable resin is 8% by mass or more, it becomes a stretchable wiring 24 with good stretchability and excellent adhesion to the stretchable resin substrate 11. If the content of the stretchable wiring 24 containing the stretchable resin is 20% by mass or less, it becomes easier to ensure the content of metal powder in the stretchable wiring 24, thus it is easier to obtain a stretchable wiring 24 with high conductivity, which is preferred.

[0116] In this embodiment, the elongation at break of the stretchable wiring 24 in the resin wiring substrate 1 is preferably 50% or more, more preferably 100% or more. When the elongation at break of the stretchable wiring 24 is 50% or more, it becomes a resin wiring substrate 1 that is more suitable for use in various stretchable devices such as wearable devices. Furthermore, the elongation at break of the stretchable wiring 24 is preferably 500% or less. This is because it is easy to create a resin wiring substrate 1 with stretchable wiring 24 that has sufficient strength and conductivity.

[0117] The resistivity of the flexible wiring 24 before expansion is preferably 2×10⁻⁶. -2 [Ωmm] or less, preferably 7×10 -3 [Ωmm] or less, further preferably 6×10 -3 [Ωmm] or less, 4×10 is particularly preferred. -3 [Ωmm] or less.

[0118] Increasing the proportion of metal powder in the stretchable wiring 24 reduces the resistivity of the stretchable wiring 24 before stretching. However, increasing the proportion of metal powder in the stretchable wiring 24 lowers the proportion of stretchable resin, resulting in a decrease in the elongation at break of the stretchable wiring 24. Therefore, the resistivity of the stretchable wiring 24 before stretching can be appropriately adjusted by changing the proportion of metal powder according to the required elongation at break and resistivity of the resin wiring substrate 1 using the stretchable wiring 24.

[0119] The flexible wiring 24 is preferably a wiring with high conductivity and flexibility, and minimal change in conductivity during stretching. This is because it results in a resin wiring substrate 1 with superior durability and reliability.

[0120] As an example of such a flexible wiring 24, one can cite the following: it contains a flexible resin and metal powder, has an elongation at break of 130% or more, and a resistivity (ρ0) of 2 × 10⁻⁶ before stretching. -2 The wiring includes metal powder with a scale-shaped powder content of [Ωmm] or less, and the proportion of elastic resin is 8% or more and 20% or less by mass.

[0121] Furthermore, other examples of the flexible wiring 24 include: a component containing a flexible resin and metal powder, with an elongation at break of 130% or more, and a resistivity (ρ) of 50% or less. 50 The ratio of the resistivity (ρ0) to the resistivity before stretching (ρ) 50 Wiring with a resistivity (ρ0) of 7 or less, containing flake-shaped metal powder, and having a resin with elasticity of 8% to 20% by mass. In this case, wiring with a resistivity (ρ0) of 100% can also be used. 100Relative resistivity (ρ) to a stretching ratio of 50% 50 The ratio (ρ) 100 / ρ 50 ( ) is for wiring below 8.

[0122] Other examples of flexible wiring 24 include: a component containing a flexible resin and metal powder, with an elongation at break of 130% or more, and a resistivity (ρ) of 100% elongation at break. 100 Relative resistivity (ρ) to a stretching ratio of 50% 50 The ratio (ρ) 100 / ρ 50 Relative resistivity (ρ) to a stretching ratio of 50% 50 The ratio of the resistivity (ρ0) to the resistivity before stretching (ρ) 50 The wiring has a change rate of less than 140% for / ρ0), the metal powder includes flake-shaped powder, and the proportion of elastic resin is more than 8% by mass and less than 20% by mass.

[0123] The "elongation at break of the flexible wiring 24" in this specification is a value calculated by the method shown below.

[0124] (Method for determining the elongation at break of elastic wiring 24)

[0125] First, on a substrate formed of PET (polyethylene terephthalate) film or the like, a sufficiently large, stretchable conductive layer containing the same stretchable resin and metal powder is manufactured to the same thickness as the stretchable wiring 24 of the resin wiring substrate 1 to be measured. Next, the stretchable conductive layer is peeled off from the substrate, and six strip-shaped test samples, each 10 mm wide and 30 mm long, are cut out. For each test sample, the elongation at break is calculated using the same method as for measuring the elongation at break of the stretchable resin substrate 11. The average value of these values ​​is taken as the elongation at break of the stretchable wiring 24, and the elongation at break of the stretchable conductive layer forming the stretchable wiring 24 (elongation at break of the stretchable wiring 24) is calculated according to the above definition.

[0126] The elongation at break of the flexible wiring 24 is defined as the elongation at break in the direction of maximum elongation at break. As long as the elongation at break of the flexible wiring 24 calculated using the above method is not anisotropic, the elongation at break will be equal in any direction. Furthermore, as long as the anisotropy of the elongation at break of the flexible wiring 24 calculated using the above method is small, the elongation at break will be a similar value in any direction.

[0127] The resistivity (ρ0) of the flexible wiring 24 before expansion and the resistivity (ρ) when the expansion rate is 50% are specified in this manual. 50), resistivity (ρ) when the scaling factor is 100% 100 ")" refers to the value calculated using the method shown below.

[0128] First, a stretchable conductive layer was fabricated using the same method as for determining elongation at break, and six strip-shaped test samples, each 10 mm wide and 30 mm long, were cut out. Next, each test sample was fixed to a metal substrate using double-sided tape, with the 10 mm wide and 10 mm long area at the center of the long side of each sample designated as the measurement area. Then, the metal substrate with each test sample was clamped at the top and bottom of the resistance meter, and the resistance values ​​of the measurement areas for each of the six test samples were measured. The average value was taken as the resistance value before stretching (R0).

[0129] Then, the measurement area of ​​each test specimen fixed to the metal substrate is extended, and the resistance value of the measurement area when the expansion rate of the measurement area is 50% in the long side direction of the test specimen is measured in the same manner as before the expansion. The average value is set as the resistance value (R) when the expansion rate is 50%. 50 ).

[0130] Furthermore, the measurement area of ​​each test specimen fixed to the metal substrate is extended, and the resistance value of the measurement area when the expansion rate is 100% on the long side of the test specimen is measured in the same manner as before the expansion. The average value is set as the resistance value (R0) when the expansion rate is 100%. 100 ).

[0131] Furthermore, a stretchable conductive layer is prepared in the same manner as the method for determining elongation at break, using a sheet-like circular sample. Next, a rectangular PET (polyethylene terephthalate) film with a side length longer than the diameter of the circular sample is placed on the circular sample. Then, the thickness of the regions in the rectangular PET film not laminated onto the circular sample is measured using, for example, a DIGIMICRO ZC-101 (manufactured by Nikon Corporation), and the average value is taken as the thickness of the PET film.

[0132] Next, for the thickness of the portion formed by stacking the circular sample and the PET film, the thickness was measured at five locations: four equally spaced locations at the edge of the circular sample and the center, and a total of five locations at the center of the circular sample. These measurements were performed using, for example, a DIGIMICRO ZC-101 (manufactured by Nikon Corporation). The average value obtained by subtracting the thickness of the PET film from the average value was taken as the thickness (t) of the stretchable wiring 24 before stretching.

[0133] Using the resistance value (R0) of the stretchable wiring 24 before stretching and the thickness (t) before stretching, as well as the width (D) and length (L) of the resistivity measurement area in the measurement sample before stretching, the resistivity (ρ0) before stretching is calculated by the following formula.

[0134] Resistivity before stretching (ρ0) = R0 × (D × t) / L

[0135] Furthermore, for the resistivity (ρ) at a stretch rate of 50%. 50 Using the resistance value (R) when the elongation is 50%. 50 The resistance value (R0) before expansion is used in the calculation. Furthermore, the resistivity (ρ) at 100% expansion is used instead. 100 Using the resistance value (R) when the expansion rate is 100%. 100 The original resistance value (R0) is used instead of the original resistance value for expansion and contraction in the calculation.

[0136] (Resin coating layer 31)

[0137] like Figure 1 , Figure 2B and Figure 2C As shown, the resin wiring substrate 1 of this embodiment has a resin covering layer 31 covering the portion of the flexible wiring 24 disposed on the first surface 11a of the flexible resin substrate 11 and the portion near the exposed portion 22b of the metal wiring 22 that contacts the flexible wiring 24. Furthermore, in this specification, the portion near the exposed portion 22b of the metal wiring 22 that contacts the flexible wiring 24 can be a portion that is 50% or less from the end 24a of the flexible wiring 24 when the length of the long side of the flexible wiring 24 is set to 100%, a portion that is 40% or less from the end 24a of the flexible wiring 24, or a portion that is 30% or less from the end 24a of the flexible wiring 24.

[0138] The resin cover layer 31 is formed of a stretchable resin. Similar to the stretchable resin substrate 11, the elongation at break of the resin cover layer 31 is preferably 50% or more, more preferably 200% or more. When the elongation at break of the resin cover layer 31 is 50% or more, the resin cover layer 31 becomes more likely to follow the stretching and contracting of the stretchable resin substrate 11, resulting in better adhesion to the stretchable resin substrate 11. As a result, the resin cover layer 31 is less likely to peel off from the stretchable resin substrate 11, and the metal wiring 22 and stretchable wiring 24 covered by the resin cover layer 31 are less likely to peel off from the stretchable resin substrate 11. Furthermore, similar to the stretchable resin substrate 11, the elongation at break of the resin cover layer 31 is preferably 4000% or less. This is because it is easy to form a resin wiring substrate 1 with sufficient strength and durability.

[0139] The “elongation at break of resin coating 31” in this specification refers to a value calculated by the method shown below.

[0140] (Method for determining the elongation at break of the resin coating layer 31)

[0141] First, a sufficiently large stretchable resin layer of the same type of stretchable resin is formed on the substrate, having the same thickness as the resin cover layer 31 of the resin wiring board 1 to be measured. Next, the stretchable resin layer is peeled off the substrate, and six strip-shaped test specimens, each 10 mm wide and 30 mm long, are cut out. For each test specimen, the elongation at break is calculated using the same method as for measuring the elongation at break of the stretchable resin substrate 11. The average value of these values ​​is taken as the elongation at break of the resin cover layer 31, and the elongation at break of the stretchable resin layer forming the resin cover layer 31 is calculated according to the above definition (elongation at break of the resin cover layer 31).

[0142] The elongation at break of the resin coating layer 31 is defined as the elongation at break in the direction of maximum elongation at break. As long as the elongation at break of the resin coating layer 31 calculated by the above method does not exhibit anisotropy, the elongation at break will be equal in any direction. Furthermore, as long as the anisotropy of the elongation at break of the resin coating layer 31 calculated by the above method is small, the elongation at break will be a similar value in any direction.

[0143] As the stretchable resin forming the resin coating layer 31, the same stretchable resin that can be used for the stretchable resin substrate 11 can be used. The stretchable resin contained in the resin coating layer 31 can be the same as or different from the stretchable resin that can be used for the stretchable resin substrate 11.

[0144] When the elastic resin contained in the resin coating layer 31 is the same as the elastic resin that can be used in the elastic resin substrate 11, it is easy to become a resin coating layer 31 with good adhesion to the elastic resin substrate 11, and therefore is preferred.

[0145] When the elastic resin contained in the resin cover layer 31 is different from the elastic resin that can be used in the elastic resin substrate 11, it is preferable to use a resin with good heat resistance such as polyimide resin, polyamide resin, epoxy resin, polycarbonate, silicone resin, polyacrylic resin, or fluororesin as the elastic resin contained in the resin cover layer 31. This is because, as a method for forming electrical connections of wiring and end wiring 23 that are electrically connected to other devices, and / or a method for electrically connecting the exposed portion 22b of the metal wiring 22 to the electronic device 41, the influence on the elastic resin substrate 11 can be suppressed by using a heat-based method.

[0146] (Electronic Components 41)

[0147] In the resin wiring board 1 of this embodiment, two electronic devices 41 are disposed on the first surface 11a of the stretchable resin substrate 11. For example... Figure 1 , Figure 2A and Figure 2C As shown, these electronic devices 41 are electrically connected to the metal wiring 22 disposed in the central part. The number and type of electronic devices 41 are not particularly limited and can be appropriately determined according to the application of the retractable device. Furthermore, the number of metal wiring 22 electrically connected to the electronic devices 41 is also not particularly limited and can be appropriately determined according to the application of the retractable device.

[0148] As electronic device 41, known electronic devices can be used. Examples of electronic devices 41 include, for example, various sensors, capacitors, inductors, high-frequency filters, transformers, resistors, rheostats, diodes, various ICs, various actuators, batteries, etc.

[0149] When the electronic device 41 is a battery, examples include: solar cells, lithium-ion batteries, and electric double-layer capacitors. From the perspective of electrode configuration, solar cells can be categorized as bifacial electrode type solar cells and back electrode type solar cells. Furthermore, from the perspective of materials, examples include inorganic material-based solar cells such as silicon-based solar cells and compound semiconductor-based solar cells, as well as organic-based solar cells.

[0150] For the resin wiring substrate 1 of this embodiment, it is preferable to use the exposed portion 22b of the metal wiring 22 as a solder pad to mount the electronic device 41. Specifically, it is preferable to use... Figure 2A and Figure 2C As shown, the exposed portion 22b of the metal wiring 22 is arranged facing the terminal 41a of the electronic device 41, and the exposed portion 22b and the terminal 41a are electrically connected by solder 42. As a preferred electronic device 41 mounted in the above manner, examples include, for instance, a semiconductor package (ball grid array; BGA) with ball solder arranged in a grid pattern on a surface facing the resin wiring substrate 1.

[0151] [Manufacturing method for flexible devices]

[0152] Next, regarding Figure 1 , Figures 2A to 2C An example of a method for manufacturing a scalable device is shown, which will be described in detail with reference to the accompanying drawings.

[0153] (The formation of wiring 25, which becomes metal wiring 22 and end wiring 23)

[0154] In this embodiment, firstly, a stretchable resin substrate 11 having metal wiring 22 and end wiring 23 is manufactured. Figures 3A to 3H For illustrative purposes Figure 1 A process diagram illustrating an example of a method for manufacturing a scalable device. Figures 3A to 3H To be with Figure 1 A magnified cross-sectional view of a portion of the area corresponding to a cross-section in a direction orthogonal to the long side of the elastic resin substrate 11 shown.

[0155] First, such as Figure 3A As shown, a sheet-shaped manufacturing substrate 5 is prepared. Known substrates such as resin substrates formed from resins like polytetrafluoroethylene (PTFE) can be used as the manufacturing substrate 5.

[0156] Next, as Figure 3B As shown, an electroplating seed layer 6 formed of a copper thin film or the like is formed on a manufacturing substrate 5 using sputtering, CVD or other methods.

[0157] Next, as Figure 3C As shown, a photoresist layer 7 is formed on the electroplating seed layer 6 using a known method. Then, the photoresist layer 7 is patterned into a shape corresponding to the planar shape of the metal wiring 22 and the length of the end wiring 23 using photolithography, so that a portion of the electroplating seed layer 6 is exposed.

[0158] Next, as Figure 3D As shown, metal wiring 22 and end wiring 23 are formed on the exposed electroplated seed layer 6 by electroplating (see reference). Figure 1 , Figures 2A to 2C 25. Wiring made of copper or the like.

[0159] Next, as Figure 3E As shown, the photoresist layer 7 is peeled off using a known method, exposing the electroplating seed crystal layer 6.

[0160] Then, as Figure 3F As shown, the exposed electroplated seed crystal layer 6 is removed by known methods such as etching.

[0161] (Formation of the stretchable resin substrate 11)

[0162] Next, in this embodiment, a stretchable resin substrate 11 is formed on a manufacturing substrate 5 having a wiring 25 that becomes a metal wiring 22 and an end wiring 23 using a resin composition comprising the above-mentioned resin component (P) and a solvent.

[0163] First, such as Figure 3GAs shown, a resin composition is coated onto a manufacturing substrate 5 having wiring 25 in a predetermined planar shape and thickness to form a resin composition layer 12 having a strip shape corresponding to the planar shape of the elastic resin substrate 11 (coating process). That is, in the coating process, the resin composition is not coated on the area where the wiring 25 formed on the manufacturing substrate 5 becomes the end wiring 23.

[0164] In the coating process, known methods can be used as the method for coating the resin composition. Specifically, as coating methods, for example, methods using various coating machines or Mayer rods, and various printing methods, such as inkjet printing, can be used.

[0165] Next, the resin composition layer 12 is dried and solidified (drying and solidification process). As a result, a sheet-like stretchable resin substrate 11 is obtained.

[0166] In the drying and solidification process, the drying temperature for drying the resin composition layer 12 is preferably 25°C or higher and 150°C or lower, more preferably 25°C or higher and 120°C or lower. If the drying temperature is 25°C or higher, the resin composition layer 12 can be dried more effectively, and a sheet-like stretchable resin substrate 11 can be effectively manufactured. If the drying temperature is 150°C or lower, the deterioration of the sheet-like stretchable resin substrate 11 due to excessively high drying temperature can be prevented.

[0167] In the drying and solidification process, the drying time for drying the resin composition layer 12 is preferably 10 minutes or more and 120 minutes or less, more preferably 30 minutes or more and 90 minutes or less. If the drying time is within the above range, a sheet-like, stretchable resin substrate 11 with good properties can be effectively manufactured. The drying time can be appropriately set according to the drying temperature when drying the resin composition layer 12.

[0168] In the drying and solidification process, the solidification (a sheet-like extensible resin substrate) has been completed by drying the resin composition layer 12. This can be confirmed, for example, by no longer observing a clear change in the mass of the resin composition layer 12 supplied for drying (the total mass of the manufacturing substrate 5, wiring 25, and resin composition layer 12).

[0169] In the above manufacturing method, a stretchable resin substrate 11 can be manufactured by coating a resin composition onto a manufacturing substrate 5 to form a resin composition layer 12 and then drying it to solidify it. Therefore, unlike a stretchable resin substrate formed by forming a resin composition layer containing a curing agent and then subjecting it to a photocuring or thermocuring reaction for curing, no adverse effects caused by the curing reaction occur.

[0170] Next, in this implementation plan, as follows: Figure 3H As shown, the sheet-like stretchable resin substrate 11 and the wiring 25 are peeled off from the manufacturing substrate 5 as a whole.

[0171] Therefore, as Figure 3H As shown, a linear metal wiring 22 and an end wiring 23 are formed. The linear metal wiring 22 has an embedded portion 22a formed in a cross-sectional view along the recess 11b formed in the first surface 11a of the elastic resin substrate 11 in a filled manner, and an exposed portion 22b that is exposed from the first surface 11a of the elastic resin substrate 11 and disposed on a plane substantially the same as the first surface 11a. The end wiring 23 is provided in such a way that it extends from the metal wiring 22 disposed at both ends of the elastic resin substrate 11, and is disposed in a position that does not overlap with the elastic resin substrate 11 in a top view.

[0172] (Form of flexible wiring 24)

[0173] Next, in this embodiment, a stretchable wiring 24 is formed on a stretchable resin substrate 11 having metal wiring 22 using a specified amount of a resin composition containing the above-mentioned resin component (P) and solvent, and metal powder such as silver powder.

[0174] First, the flexible electrical wiring paste is applied to the flexible resin substrate 11 having the metal wiring 22 in a shape corresponding to the planar shape of the flexible wiring 24, forming a wiring paste layer of a specified thickness (coating process).

[0175] In the coating process, known methods can be used as the method for applying the stretchable electrical wiring paste. Specifically, as coating methods, for example, methods using various coating machines or Mayer rods, or various printing methods such as inkjet printing can be used.

[0176] In this implementation plan, such as Figure 3H As shown, the exposed portion 22b of the metal wiring 22 is formed on a plane that is substantially the same as the first surface 11a of the stretchable resin substrate 11. Therefore, by applying stretchable electrical wiring paste in a predetermined shape to the stretchable resin substrate 11 having the metal wiring 22, it is possible to easily apply stretchable electrical wiring paste to the area in the exposed portion 22b of the metal wiring 22 that is electrically connected to the stretchable wiring 24.

[0177] Next, the wiring paste layer is dried to solidify (drying and solidification process). This yields flexible wiring 24.

[0178] In the drying and solidification process, the drying temperature used to dry the wiring paste layer is preferably 25°C or higher and 150°C or lower, more preferably 25°C or higher and 120°C or lower. If the drying temperature is 25°C or higher, the wiring paste layer can be dried more effectively, and the stretchable wiring 24 can be manufactured more effectively. If the drying temperature is 150°C or lower, the deterioration of the stretchable resin substrate 11 and the stretchable wiring 24 due to excessively high drying temperature can be prevented.

[0179] In the drying and solidification process, the drying time for drying the wiring paste layer is preferably 10 minutes or more and 120 minutes or less, more preferably 30 minutes or more and 90 minutes or less. If the drying time is within the above range, it is possible to effectively manufacture flexible wiring 24 with good properties. The drying time can be appropriately set according to the drying temperature when drying the wiring paste layer.

[0180] In the drying and solidification process, the solidification (obtaining the stretchable wiring 24) has been completed by drying the wiring paste layer. This can be confirmed, for example, by no longer observing a clear change in the mass of the wiring paste layer supplied for drying (the total mass of the stretchable resin substrate 11, the metal wiring 22, the end wiring 23, and the wiring paste layer).

[0181] Through the above process, by being disposed on the first surface 11a of the stretchable resin substrate 11 and having two ends 24a connected to the exposed portion 22b of the metal wiring 22, a stretchable linear wiring 24 electrically connected to the metal wiring 22 can be formed.

[0182] In the above manufacturing method, the flexible wiring 24 can be manufactured by applying a flexible electrical wiring paste to a flexible resin substrate 11 having metal wiring 22 using, for example, an inkjet printer or a dispensing machine, to form a wiring paste layer, and then drying it to solidify. Therefore, unlike flexible wiring formed by forming a wiring paste layer containing a curing agent and then subjecting it to a photocuring or thermocuring reaction for curing, no adverse effects caused by the curing reaction occur.

[0183] (Formation of resin coating layer 31)

[0184] Next, in this embodiment, a resin composition containing resin component (P) and solvent, which is used in forming the stretchable resin substrate 11, is used to form a stretchable resin cover layer 31 on the first surface 11a of the stretchable resin substrate 11 having metal wiring 22 and stretchable wiring 24.

[0185] First, the resin composition used in forming the stretchable resin substrate 11 is applied to the first surface 11a of the stretchable resin substrate 11 having metal wiring 22 and stretchable wiring 24 in a shape corresponding to the planar shape of the resin cover layer 31, forming a resin composition layer of a predetermined thickness (coating process).

[0186] In the coating process, the same method that can be used as the method for coating the resin composition can be used when forming the elastic resin substrate 11.

[0187] Next, the resin composition layer is dried in the same manner as when forming the stretchable resin substrate 11 to solidify (drying and solidification process). As a result, a resin cover layer 31 is formed, which covers the portion near the exposed portion 22b of the stretchable wiring 24 and the metal wiring 22 disposed on the first surface 11a of the stretchable resin substrate 11, and the portion that contacts the stretchable wiring 24.

[0188] In the drying and solidification process, similar to the process of forming the stretchable resin substrate 11, the drying temperature for drying the resin composition layer is preferably 25°C or higher and 150°C or lower, more preferably 25°C or higher and 120°C or lower. If the drying temperature is above 25°C, the resin composition layer can be dried more effectively, and the resin coating layer 31 can be manufactured more efficiently. If the drying temperature is below 150°C, the deterioration of the stretchable resin substrate 11 with the stretchable wiring 24 and the resin coating layer 31 due to excessively high drying temperature can be prevented.

[0189] In the drying and solidification process, similar to the process of forming the elastic resin substrate 11, the drying time for drying the resin composition layer is preferably 10 minutes or more and 120 minutes or less, more preferably 30 minutes or more and 90 minutes or less. If the drying time is within the above range, a resin coating layer 31 with good properties can be effectively manufactured. The drying time can be appropriately set according to the drying temperature when drying the resin composition layer.

[0190] In the drying and solidification process, the solidification has been completed by drying the resin composition layer (resin cover layer 31 has been obtained), which can be confirmed, for example, by no longer observing a clear change in the mass of the resin composition layer supplied for drying (the total mass of the stretchable resin substrate 11, metal wiring 22, end wiring 23, stretchable wiring 24, and the resin composition layer).

[0191] In the above manufacturing method, a resin composition layer 31 with elasticity is manufactured by coating a resin composition onto the first surface 11a of a stretchable resin substrate 11 having metal wiring 22 and stretchable wiring 24 to form a resin composition layer, and then drying it to solidify it. Therefore, unlike a resin coating layer formed by forming a resin composition layer containing a curing agent and then subjecting it to a photocuring reaction or a thermocuring reaction for curing, the adverse effects of the curing reaction described below will not occur.

[0192] For example, in the case of a stretchable resin layer formed by coating a resin composition containing resin component (P), solvent, and curing agent, and then curing it using a photocuring or thermocuring reaction, significant deviations in crosslinking density can easily occur due to uneven curing of the resin component (P) within the resin composition layer. Areas with low crosslinking density in the stretchable resin layer tend to have insufficient strength. Furthermore, these areas are prone to deterioration and breakage due to repeated stretching and contraction. Additionally, stretchable resin layers cured using photocuring or thermocuring reactions, due to the presence of a curing agent, are susceptible to deterioration over time due to heat and / or light.

[0193] In particular, when a resin composition layer is formed on a substrate containing wiring, electronic components, or other components and then cured by irradiation with ultraviolet light, the cross-linking density is low in the surrounding areas of the stretchable resin layer around the wiring, electronic components, or other components, leading to areas of insufficient curing. Furthermore, when a resin composition layer is formed on a substrate containing wiring, electronic components, or other components and then cured by a thermosetting reaction, areas with low cross-linking density are easily created in the stretchable resin layer due to heat distribution during curing. Moreover, in the case of thermosetting curing, differential shrinkage of the resin composition layer is easily generated due to heat distribution during curing, making it prone to peeling of the wiring, electronic components, or other components.

[0194] (Installation of electronic component 41)

[0195] Next, in this embodiment, using known methods such as surface mount technology (SMT) machines, the electronic device 41 is positioned at a predetermined location on the first surface 11a of a stretchable resin substrate 11 having a resin cover layer 31, metal wiring 22, and stretchable wiring 24. Then, using known methods such as molten solder, conductive adhesive, or anisotropic adhesive, the terminals 41a of the electronic device 41 are connected to the exposed portion 22b of the metal wiring 22 as follows: Figure 2A and Figure 2C Make the electrical connection as shown.

[0196] Specifically, when the heat resistance temperature of the metal wiring 22 is 220°C or higher and the electronic device 41 is a ball grid array (BGA), the following method can be used. First, molten solder is printed at a predetermined position on the exposed portion 22b of the metal wiring 22. Next, the solder balls (terminals) of the ball grid array (BGA) are aligned with a predetermined position on the first surface 11a of the stretchable resin substrate 11. Then, the exposed portion 22b is heated in a reflow oven to solder the solder balls (terminals) of the ball grid array. By means of this method, the electronic device 41 is electrically connected to the metal wiring 22.

[0197] After mounting the electronic device 41 on the first surface 11a of the elastic resin substrate 11 in the above manner, the wiring and end wiring 23 that are electrically connected to other devices can be electrically connected by known methods as needed, thereby electrically connecting the resin wiring board 1 to other devices.

[0198] By implementing the above procedures, the scalable equipment of this implementation plan can be obtained.

[0199] The resin wiring substrate 1 of the present invention has a stretchable resin substrate 22 and a wiring pattern 21. The wiring pattern 21 includes metal wiring 22 formed of a metal film with a particle size of 0.5 μm to 2.0 μm. A portion of the metal wiring 22 in a top view is covered by the stretchable resin substrate 11 and a resin capping layer 31 formed of stretchable resin in a cross-sectional view. Therefore, compared to a case without, for example, the resin capping layer 31, the metal wiring 22 of the resin wiring substrate 1 of this embodiment is less likely to peel off from the stretchable resin substrate 11. Furthermore, for the resin wiring substrate 1 of this embodiment, since the resin capping layer 31 is formed of stretchable resin, the resin capping layer 31 can follow the stretching and contraction of the stretchable resin substrate 11, and the resin capping layer 31 has good adhesion to the stretchable resin substrate 11. In summary, even if the stretchable resin substrate 11 stretches or contracts, the metal wiring 22 of the resin wiring substrate 1 of this embodiment is less likely to peel off from the stretchable resin substrate 11. Therefore, the resin wiring board 1 of this embodiment has excellent durability and reliability.

[0200] Furthermore, compared to, for example, a stretchable wiring 24 containing metal powder and a stretchable resin, the metal wiring 22 exhibits superior conductivity and heat resistance. Therefore, the resin wiring substrate 1 of this embodiment possesses the stretchability provided by the stretchable resin substrate 11, and also possesses the excellent conductivity and heat resistance provided by the metal wiring 22.

[0201] Furthermore, in the resin wiring substrate 1 of this embodiment, the metal wiring 22 has an embedded portion 22a formed along the recess 11b formed in the first surface 11a of the stretchable resin substrate 11 in cross-sectional view, and an exposed portion 22b exposed from the first surface 11a. Therefore, compared to, for example, where the metal wiring 22 is only in contact with the first surface 11a of the stretchable resin substrate 11, the resin wiring substrate 1 of this embodiment has a large contact area between the metal wiring 22 and the stretchable resin substrate 11, resulting in good adhesion to the stretchable resin substrate 11. Moreover, in the resin wiring substrate 1 of this embodiment, the embedded portion 22a of the metal wiring 22 is held by the recess 22b. In summary, the metal wiring 22 of the resin wiring substrate 1 of this embodiment is less likely to peel off from the stretchable resin substrate 11.

[0202] Furthermore, in the resin wiring substrate 1 of this embodiment, only a portion of the metal wiring 22 in the top view is covered by the stretchable resin substrate 11 and the resin capping layer 31 in the cross-sectional view. The wiring pattern 21 has a stretchable linear wiring 24 disposed on the first surface 11a, and the two ends 24a of the stretchable wiring 24 are formed to connect with the exposed portion 22b of the metal wiring 22. Because the stretchable wiring 24 is stretchable, it follows the deformation of the stretchable resin substrate 11 when the stretchable resin substrate 11 expands or contracts. Therefore, the stretchable wiring 24 is not easily peeled off from the stretchable resin substrate 11. Therefore, compared to the case where the wiring pattern 21 is only composed of metal wiring 22, the wiring pattern 21 of the resin wiring substrate 1 of this embodiment is not easily peeled off from the stretchable resin substrate 11, and has excellent durability and reliability.

[0203] Furthermore, in the resin wiring substrate 1 of this embodiment, the portion near the exposed portion 22b of the metal wiring 22 that contacts the stretchable wiring 24 is covered by a stretchable resin covering layer 31. Therefore, even if the stretchable resin substrate 11 expands or contracts, the metal wiring 22 of the resin wiring substrate 1 is less likely to peel off from the stretchable resin substrate 11, which is preferable.

[0204] Furthermore, in the resin wiring substrate 1 of this embodiment, the stretchable wiring 24 disposed on the first surface 11a of the stretchable resin substrate 11 is covered by a resin capping layer 31. The stretchable wiring 24 covered by the resin capping layer 31 can more easily follow the deformation of the stretchable resin substrate 11. Therefore, the stretchable wiring 24 covered by the resin capping layer 31 is less likely to peel off from the stretchable resin substrate 11.

[0205] Furthermore, since the scalable device of this embodiment has the resin wiring substrate 1 of this embodiment, even if the scalable resin substrate 11 expands or contracts, the metal wiring 22 is not easily peeled off from the scalable resin substrate 11, and has excellent durability and reliability.

[0206] In particular, in the scalable device of this embodiment, only a portion of the metal wiring 22 in the top view is covered by the scalable resin substrate 11 and the resin cover layer 31 in the cross-sectional view. The exposed portion 22b of the metal wiring 22 is arranged facing the terminal 41a of the electronic device 41, and the exposed portion 22b and the terminal 41a are electrically connected by solder. Therefore, the effect of improving durability and reliability brought about by having the resin wiring substrate 1 of this embodiment is significant.

[0207] More specifically, for example, when using a resin wiring substrate in which the metal wiring is only connected to the first surface 11a of the stretchable resin substrate 11, and the side of the metal wiring opposite to the stretchable resin substrate 11 is arranged facing the terminal 41a of the electronic device 41 and joined by solder, instead of the resin wiring substrate 1 of this embodiment, if the stretchable resin substrate 11 deforms, the metal wiring soldered to the terminal 41a of the electronic device 41 can easily peel off from the stretchable resin substrate 11.

[0208] However, when using the resin wiring substrate 1 of this embodiment, if the stretchable resin substrate 11 deforms, the stretchable resin substrate 11, which is arranged between the metal wirings 22 soldered to the terminals 41a of the electronic device 41 with sufficient contact area, absorbs the stress generated by the deformation while maintaining the metal wirings 22. Therefore, even if the stretchable resin substrate 11 deforms, the metal wirings 22 soldered to the terminals 41a of the electronic device 41 are not easily peeled off from the stretchable resin substrate 11.

[0209] [Other Examples]

[0210] The embodiments of the present invention have been described in detail above. However, the various components and combinations in each embodiment are only examples, and additions, omissions, substitutions and other changes can be made to the components without departing from the spirit of the present invention.

[0211] For example, in the above embodiment, the example described is that only a portion of the metal wiring 22 in the top view is covered by the stretchable resin substrate 11 and the resin coating layer 31 in the cross-sectional view. However, it is sufficient for at least a portion of the metal wiring 22 to be covered by the stretchable resin substrate 11 and the resin coating layer 31 in the cross-sectional view; alternatively, the entire metal wiring 22 can be covered by the stretchable resin substrate 11 and the resin coating layer 31 in the cross-sectional view. In this case, the metal wiring 22 is less likely to peel off from the stretchable resin substrate 11.

[0212] Furthermore, in the above embodiment, the example described is that the exposed portion 22b of the metal wiring 22 is formed on a plane substantially the same as the first surface 11a of the stretchable resin substrate 11. However, the exposed portion 22b and the first surface 11a of the stretchable resin substrate 11 may not be formed on substantially the same plane. That is, the exposed portion 22b may be formed in a form that protrudes from the first surface 11a of the stretchable resin substrate 11, or it may be formed inside the recess 11b formed on the first surface 11a of the stretchable resin substrate 11.

[0213] Furthermore, in the above embodiment, the wiring pattern 21 of the stretchable resin substrate 11 is described as an example consisting of metal wiring 22, end wiring 33 and stretchable wiring 24. However, the wiring pattern of the resin wiring substrate in the present invention may have metal wiring 22 with embedded portion 22a and exposed portion 22b, or it may not have end wiring 33 and stretchable wiring 24.

[0214] Furthermore, in the above embodiment, an example was described with a resin covering layer 31 covering the stretchable wiring 24 disposed on the first surface 11a of the stretchable resin substrate 11 and the portion near the exposed portion 22b of the metal wiring 22 that contacts the stretchable wiring 24. However, the resin covering layer in the resin wiring substrate of the present invention may only cover a portion of the exposed portion 22b of the metal wiring 22, or it may only cover the stretchable wiring 24. Furthermore, the resin wiring substrate of the present invention may not have a resin covering layer.

[0215] Furthermore, in the above embodiment, the example described is a metal wiring 22 with a uniform width in a top view. However, the metal wiring 22 can also be configured as having a wide area in a top view, specifically the portion of the exposed portion 22b that contacts the retractable wiring 24 and / or the portion that connects to the terminal 41a of the electronic device 41. In this case, when the metal wiring 22 is electrically connected to the retractable wiring 24 or the electronic device 41, the exposed portion 22b can more appropriately function as a solder pad.

[0216] Furthermore, the above implementation scheme is illustrated using the case where the stretchable resin substrate 11 is a single sheet, but the stretchable resin substrate can also be composed of multiple sheet-like stretchable resin substrates.

[0217] Example

[0218] <Evaluation of Flexible Wiring>

[0219] [Experimental Example 1]

[0220] Weigh 100 parts by weight of urethane acrylate oligomer (product name: UN-5500, manufactured by Negami Chemical Industrial Co., Ltd.) as resin (a), 0.8 parts by weight of 2,2'-azobis(2-methylpropionic acid) dimethyl ester (product name: V601, manufactured by FUJIFILM Wako Pure Chemical Corporation) as azo polymerization initiator, and 0.245 parts by weight of the compound represented by the following formula (1)-1 (manufactured by FUJIFILM Wako Pure Chemical Corporation) as RAFT agent in a flask, and mix them at room temperature using a stirrer.

[0221] [Chemical Formula 2]

[0222]

[0223] Furthermore, diethylene glycol monobutyl ether acetate (BCA) was added to the flask as a solvent to achieve a resin (a) content of 15% by mass. The mixture was then subjected to reversible addition-fragmentation chain transfer polymerization (RAFT polymerization) at 90°C for 20 minutes under a nitrogen atmosphere and stirring in an oil bath. This yielded a resin composition containing resin component (P) with urethane bonds and solvent in the proportions shown in Table 1.

[0224] Next, the resin composition containing resin component (P) and solvent, and silver powder as metal powder (proportion of flake-shaped powder: 12.5 [mass%], average maximum particle size of flake-shaped powder: 3 μm) are weighed and mixed at room temperature using a mixer to obtain a stretchable electrical wiring paste. The obtained stretchable electrical wiring paste is then coated onto a substrate made of PET (polyethylene terephthalate) film (coating process) to form a wiring paste layer.

[0225] Next, the wiring paste layer is dried at 80°C for 10 minutes to solidify (drying and solidification process). This yields a 7 μm thick stretchable conductive layer (stretchable wiring) containing resin component (P) in the proportions shown in Table 1.

[0226] From the stretchable conductive layer obtained in the above manner, samples (strip test samples and circular samples) of the stretchable wiring 24 were taken, and the elongation at break and the resistivity (ρ0) before stretching were determined by the above method. The results are shown in Table 1. Furthermore, the resistivity (ρ0) at a stretching rate of 50% was determined by the above method. 50 ), resistivity (ρ) when the scaling factor is 100% 100 )), calculate ρ 50 / ρ0、ρ100 / ρ 50 、(ρ 100 / ρ 50 ) relative to (ρ 50 The rate of change of / ρ0). The results are shown in Table 1.

[0227] [Table 1]

[0228]

[0229] (Experiments 2-5, 21, 22)

[0230] Except for obtaining a stretchable conductive layer containing resin component (P) with the proportions shown in Table 1 by changing the content of the urethane bond-containing resin component (P) in the stretchable electrical wiring paste, the stretchable conductive layer was manufactured in the same manner as in Experimental Example 1, and the above-mentioned characteristics were measured in the same manner as in Experimental Example 1. The results are shown in Table 1.

[0231] (Experiments 6-9, Experiments 23-25)

[0232] Except for obtaining a resin composition containing a resin component (P) with urethane bonds and a solvent in the proportions shown in Table 1 by changing the solution polymerization conditions in RAFT polymerization, a stretchable conductive layer was manufactured in the same manner as in Experimental Example 1, and the above-mentioned properties were measured in the same manner as in Experimental Example 1. The results are shown in Table 1.

[0233] (Experimental Example 26)

[0234] Except that silver powder without flake-shaped powder was used as the silver powder, a stretchable conductive layer was manufactured in the same manner as in Experimental Example 9, and the above-mentioned properties were measured in the same manner as in Experimental Example 1. The results are shown in Table 1.

[0235] (Experimental Example 27)

[0236] Except for adding a curing agent to the flexible electrical wiring paste and using heating instead of a drying and solidification process to cure the flexible electrical wiring paste, the flexible conductive layer was manufactured in the same manner as in Experimental Example 9, and the above-mentioned properties were measured in the same manner as in Experimental Example 1. The results are shown in Table 1.

[0237] (Experimental Examples 10-14)

[0238] Except for changing the proportion of flake-shaped powder in the silver powder, a stretchable conductive layer was manufactured in the same manner as in Experimental Example 3, and the above-mentioned properties were measured in the same manner as in Experimental Example 1. The results are shown in Table 1.

[0239] The missing values ​​in Table 1 are due to the inability to measure or the failure to perform the measurement.

[0240] As shown in Table 1, for Experimental Examples 1 to 5, where the proportion of resin component (P) in the wiring is 8% by mass (mass of resin component (P): mass of metal powder = 8:92) or higher, the elongation at break is 130% or higher, and the elongation at break is even higher for the experimental examples with a higher proportion of resin component (P).

[0241] On the other hand, as shown in Table 1, for Experimental Example 5 and Experimental Example 22, where the proportion of resin component (P) in the wiring is 20% by mass or more, the resistivity (ρ0) before expansion and contraction is 1×10⁻⁶. -2 [Ωcm] and above.

[0242] To achieve a balance between higher elongation at break (over 150%) and lower resistivity before stretching (ρ0) (5×10) -3 From the perspective of [Ωcm] or less, the proportion of resin component (P) in the wiring is preferably 10% by mass or more and 18% by mass or less.

[0243] Furthermore, in Experiment 5, where the resin composition (P) of the resin in the wiring was 20% by mass or more, the resistivity before stretching was slightly higher, at 1.53 × 10⁻⁶. -2 [Ωcm]. However, Experimental Example 5 reflects a high elongation at break, (ρ 50 / ρ0) is relatively low, at 1.7, (ρ 100 / ρ 50 The value is also sufficiently low, at 4.0. Therefore, it balances high elongation at break (over 150%) with low (ρ) 50 / ρ0) and (ρ 100 / ρ 50 From the perspective of ), the proportion of resin component (P) in the wiring is preferably 10% by mass or more and 20% by mass or less.

[0244] Furthermore, it simultaneously satisfies high elongation at break (over 150%), low resistivity before expansion (ρ0), and low (ρ... 50 / ρ0), low (ρ) 100 / ρ 50 ) and low (ρ) 100 / ρ 50 ) relative to (ρ 50 From the perspective of the rate of change of / ρ0), the proportion of resin component (P) in the wiring is preferably 10% by mass or more and 15% by mass or less.

[0245] As shown in Table 1, for resin components (P) containing 15% by mass or less of urethane bonds, as experimental examples 23-25, the elongation at break was 40% or less. On the other hand, for resin component (P) containing 25% by mass of urethane bonds, as experimental example 8, the elongation at break was 245.5%. Furthermore, for experimental example 9, which contained 30% by mass of urethane bonds, the elongation at break was 130.4%.

[0246] In summary, from the perspective of high elongation at break (150% or more), the proportion of urethane bonds in the resin component (P) containing urethane bonds is preferably 17.5% by mass or more and 25% by mass or less. Furthermore, to balance higher elongation at break (150% or more) with lower resistivity before stretching (ρ0) (7 × 10⁻⁶), [further details are needed]. -3 From the perspective of [Ωcm] or less, the proportion of urethane bonds in resin component (P) is preferably 20% by mass or more and 25% by mass or less.

[0247] To balance high elongation at break (over 150%) and low (ρ) 50 / ρ0) and (ρ 100 / ρ 50 From the perspective of ), the proportion of urethane bonds in resin component (P) is preferably 17.5% by mass or more and 25% by mass or less.

[0248] To simultaneously achieve high elongation at break (over 150%), low resistivity before stretching (ρ0), and low (ρ... 50 / ρ0), low (ρ) 100 / ρ 50 ), and low (ρ) 100 / ρ 50 ) relative to (ρ 50 From the perspective of the rate of change of / ρ0), the proportion of urethane bonds in resin component (P) is preferably 17.5% by mass or more and 22% by mass or less.

[0249] Furthermore, as shown in Table 1, for Experiment 26, which used silver powder without flake-shaped powder as silver powder, the resistivity (ρ0) before stretching was very high.

[0250] Furthermore, in Experiment 27, which involved adding a curing agent to the same stretchable electrical wiring paste as Experiment 9 and then performing a curing reaction, the elongation at break was less than 10%.

[0251] Furthermore, as shown in Table 1, for experimental examples 3, 10–14 where the proportion of flake-shaped powder in the silver powder is 2.5% by mass or more and 50% by mass or less, it is possible to achieve both higher elongation at break (over 150%) and lower resistivity before stretching (ρ0) (7 × 10⁻⁶). -3 [Ωcm] or less). However, if more than 40% by mass of flake-shaped powder is used as silver powder, the elongation at break gradually decreases. Furthermore, in Experimental Example 13, which contains 40% by mass of flake-shaped powder as silver powder, (ρ... 100 / ρ 50 ) relative to (ρ 50 The rate of change of / ρ0) is over 130%. Furthermore, in Experiment 14, which contained 50% by mass of flake-shaped powder as silver powder, (ρ) 50 The ratio of / ρ0) is 51, which is a very high result.

[0252] To balance high elongation at break (over 150%) and low (ρ) 50 / ρ0) and (ρ 100 / ρ 50 From the perspective of ), the proportion of scale-shaped powder in silver powder is preferably 2.5% by mass or more and 40% by mass or less.

[0253] Furthermore, it simultaneously satisfies high elongation at break (over 150%), low resistivity before expansion (ρ0), and low (ρ... 50 / ρ0) and (ρ 100 / ρ 50 ), low (ρ) 100 / ρ 50 ) relative to (ρ 50 From the perspective of the rate of change of / ρ0), the proportion of scale-shaped powder in silver powder is preferably 2.5% by mass or more and 12.5% ​​by mass or less.

[0254] Industrial applicability

[0255] According to the present invention, a resin wiring substrate having metal wiring that is not easily peeled off from a self-stretching resin substrate and a stretchable device having the resin wiring substrate are made possible.

[0256] Explanation of reference numerals in the attached figures

[0257] 1: Resin wiring substrate; 11: Stretchable resin substrate; 11a: First surface; 11b: Recess; 12: Resin composition layer; 21: Wiring pattern; 22: Metal wiring; 22a: Embedded portion; 22b: Exposed portion; 23: End wiring; 24: Stretchable wiring; 25: Wiring; 31: Resin covering layer.

Claims

1. A resin wiring board having a stretchable resin substrate and a wiring pattern, The wiring pattern comprises metal wiring formed from metal films with a particle size of 0.5 μm to 2.0 μm. At least a portion of the metal wiring is covered in a cross-sectional view by the stretchable resin substrate and a resin coating layer formed of the stretchable resin.

2. The resin wiring substrate according to claim 1, wherein, The metal wiring has an embedded portion formed along a recess in a first surface of the elastic resin substrate in a cross-sectional view, and an exposed portion exposed from the first surface.

3. The resin wiring board according to claim 2, wherein, The exposed portion is formed on the same plane as the first surface.

4. The resin wiring substrate according to claim 2, wherein, At least a portion of the exposed portion is covered by a resin coating layer formed of a stretchable resin.

5. The resin wiring board according to claim 2, wherein, The wiring pattern has elastic linear wiring disposed on the first surface. Only a portion of the metal wiring is covered by the elastic resin substrate and the resin coating in the cross-sectional view. One or both ends of the flexible wiring are formed in such a way that they are connected to the exposed portion of the metal wiring.

6. The resin wiring board according to claim 1, wherein, The elongation at break of the elastic resin substrate is 50% or more.

7. The resin wiring board according to claim 1, wherein, The heat resistance temperature of the metal wiring is above 200℃.

8. The resin wiring board according to claim 1, wherein, The elongation at break of the resin coating is 50% or more.

9. A scalable device comprising a resin wiring board according to any one of claims 1 to 8.

10. A scalable device comprising a resin wiring board according to any one of claims 2 to 8, Only a portion of the metal wiring is covered by the elastic resin substrate and the resin coating in the cross-sectional view. The exposed portion of the metal wiring is arranged facing the terminals of the electronic device. The exposed portion and the terminal are electrically connected by solder.

Images