JP7318246B2 - wiring board - Google Patents

Description

An embodiment of the present disclosure relates to a wiring board including a stretchable base material and wiring.

In recent years, research has been conducted on electronic devices having deformability such as stretchability. For example, it is known to form elastic silver wiring on an elastic base material or to form horseshoe-shaped wiring on an elastic base material (for example, Patent Document 1). Further, Patent Document 2 discloses a method for manufacturing a wiring board having stretchability. The manufacturing method described in Patent Document 2 employs a step of forming a circuit on a pre-stretched base material, and relaxing the base material after forming the circuit.

JP 2013-187308 A Japanese Patent Application Laid-Open No. 2007-281406

Compared to wiring formed on a rigid base material (also called a rigid base material), which does not require elasticity, wiring formed on a base material with elasticity deforms as the base material expands and contracts. Depending on the frequency and degree of expansion and contraction of the wiring, deterioration of the wiring, such as disconnection or an increase in resistance, is likely to occur. Continuing to use the electronic device without noticing such wiring deterioration may impair the function of the electronic device or cause an accident.

An object of the embodiments of the present disclosure is to provide a wiring board that can effectively solve such problems.

As a result of various studies, the present inventor found that the above problem can be solved by providing a portion having a weak mechanical strength against deformation in the structure of the wiring formed on the elastic base material, and the present invention. It is completed.

That is, one embodiment of the present disclosure includes a first surface and a second surface located on the opposite side of the first surface, a base material having elasticity, and a base material located on the first surface side of the base material and a wiring, wherein the width of the wiring in the one wiring is partially different.

Further, one embodiment of the present disclosure includes a first surface and a second surface located on the opposite side of the first surface, a base material having elasticity, and a base material located on the first surface side of the base material and a plurality of wirings, the plurality of wirings including a first wiring and a second wiring, the first wiring being a first wiring having a partially narrow wiring width in the first wiring. The second wiring has a second wiring narrow portion in which the width of the wiring in the second wiring is partially narrow, and the width of the first wiring narrow portion is equal to the width of the second wiring. The wiring substrate is smaller than the width of the narrow portion.

Further, one embodiment of the present disclosure includes a first surface and a second surface located on the opposite side of the first surface, a base material having elasticity, and a base material located on the first surface side of the base material and a first wiring, wherein in the in-plane direction of the first surface of the base material, the one wiring has a first direction portion extending in a first direction and a curve bending from the first direction to a second direction. and a second direction portion extending in the second direction, wherein the width of the wire in the curved portion is smaller than the width of the wire in the first direction portion and the width of the wire in the second direction portion. , is a wiring board.

Further, one embodiment of the present disclosure includes a first surface and a second surface located on the opposite side of the first surface, a base material having elasticity, and a base material located on the first surface side of the base material and a plurality of wirings, wherein the plurality of wirings includes a first wiring and a second wiring, and the first wiring is arranged in the first direction in the in-plane direction of the first surface of the base material. a first direction portion extending in the first direction, a first wiring curved portion bending from the first direction to the second direction, and a second direction portion extending in the second direction, and the width of the wiring in the first direction portion and the width of the wiring in the first wiring curved portion is smaller than the width of the wiring in the second direction portion, and the second wiring includes a third direction portion extending in the third direction and a third direction portion extending from the third direction. It has a second wire curved portion that bends in four directions and a fourth direction portion that extends in the fourth direction, and the width of the wire in the third direction portion and the width of the wire in the fourth direction portion are greater than the width of the wire in the fourth direction portion. In the wiring board, the width of the wiring in the second wiring curved portion is small, and the width of the wiring in the first wiring curved portion is smaller than the width of the wiring in the second wiring curved portion.

Further, one embodiment of the present disclosure includes a first surface and a second surface located on the opposite side of the first surface, a base material having elasticity, and a base material located on the first surface side of the base material and a wiring, wherein the wiring is partially made of different materials.

Further, one embodiment of the present disclosure includes a first surface and a second surface located on the opposite side of the first surface, a base material having elasticity, and a base material located on the first surface side of the base material and a wiring, wherein the thickness of the wiring in the one wiring is partially different.

Further, one embodiment of the present disclosure includes a first surface and a second surface located on the opposite side of the first surface, a base material having elasticity, and a base material located on the first surface side of the base material and a plurality of wirings, the plurality of wirings including a first wiring and a second wiring, the first wiring being a first wiring having a partially thin wiring thickness in the first wiring. a wiring thin portion, wherein the second wiring has a second wiring thin portion in which the thickness of the wiring in the second wiring is partially small; and the thickness of the first wiring thin portion A wiring substrate having a thickness smaller than that of the second wiring thin portion.

Further, one embodiment of the present disclosure includes a first surface and a second surface located on the opposite side of the first surface, a base material having elasticity, and a base material located on the first surface side of the base material one wiring, and a strength adjustment layer overlapping the one wiring when viewed along the normal direction of the first surface of the base, wherein the thickness of the strength adjustment layer is partially It is a different wiring board.

In the wiring board according to an embodiment of the present disclosure, the strength adjustment layer may have an elastic modulus larger than that of the base material.

Further, one embodiment of the present disclosure includes a first surface and a second surface located on the opposite side of the first surface, a base material having elasticity, and a base material located on the first surface side of the base material and a plurality of wirings, wherein the plurality of wirings includes a first wiring and a second wiring, and when viewed along the normal direction of the first surface of the base material, the first wiring The wiring has a first strength adjustment layer that overlaps with the first wiring, the second wiring has a second strength adjustment layer that overlaps with the second wiring, and the first strength adjustment is performed. The layer has a first strength adjustment layer thin portion in which the thickness of the first strength adjustment layer is partially small, and the second strength adjustment layer has a thickness of the thickness of the second strength adjustment layer is partially reduced. The wiring board has a relatively small second strength adjustment layer thin portion, and the thickness of the first strength adjustment layer thin portion is smaller than the thickness of the second strength adjustment layer thin portion.

In the wiring board according to one embodiment of the present disclosure, the first strength adjustment layer and the second strength adjustment layer may have an elastic modulus larger than that of the base material.

Further, one embodiment of the present disclosure includes a first surface and a second surface located on the opposite side of the first surface, a base material having elasticity, and a base material located on the first surface side of the base material and a wiring substrate, wherein the thickness of the base material overlapping the one wiring is partially different when viewed along the normal direction of the first surface of the base material. .

Further, one embodiment of the present disclosure includes a first surface and a second surface located on the opposite side of the first surface, a base material having elasticity, and a base material located on the first surface side of the base material and a plurality of wirings, wherein the plurality of wirings includes a first wiring and a second wiring, and when viewed along the normal direction of the first surface of the base, the base is , a first base material thin portion in which the thickness of the base material is partially thin overlapping the first wiring, and a second base material in which the thickness of the base material is partially thin and overlaps the second wiring The wiring board has a thin portion, wherein the thickness of the thin portion of the first base material is smaller than the thickness of the thin portion of the second base material.

In the wiring board according to one embodiment of the present disclosure, the wiring has peaks and valleys in the normal direction of the first surface of the base material repeated along the in-plane direction of the first surface of the base material. It may have an appearing bellows shape.

In the wiring board according to one embodiment of the present disclosure, the amplitude of peaks and valleys appearing in a portion overlapping the bellows shape on the second surface of the base material opposite to the first surface is equal to that of the base material. The amplitude may be smaller than the amplitude of peaks and valleys appearing in a portion of the first surface of the material that overlaps with the bellows shape.

In the wiring board according to one embodiment of the present disclosure, the amplitude of peaks and valleys appearing in a portion overlapping the bellows shape on the second surface of the base material opposite to the first surface is equal to that of the base material. The amplitude may be 0.9 times or less of the amplitude of peaks and valleys appearing in the portion of the first surface of the material that overlaps with the bellows shape.

In the wiring board according to an embodiment of the present disclosure, the period of peaks and valleys appearing in a portion overlapping the bellows shape on the second surface of the base material opposite to the first surface is equal to the base material. The pitch may be greater than the period of peaks and valleys appearing in a portion of the first surface of the material that overlaps with the bellows shape.

In the wiring board according to an embodiment of the present disclosure, the period of peaks and valleys appearing in a portion overlapping the bellows shape on the second surface of the base material opposite to the first surface is equal to the base material. It may be 1.1 times or more the period of peaks and valleys appearing in a portion of the first surface of the material that overlaps with the bellows shape.

In the wiring board according to one embodiment of the present disclosure, the positions of peaks and valleys appearing in a portion overlapping the bellows shape on the second surface of the base material opposite to the first surface are aligned with the base material. The position of the troughs and ridges appearing in the portion of the first surface of the material that overlaps with the bellows shape may be displaced.

In the wiring board according to an embodiment of the present disclosure, when the period of peaks and valleys appearing in a portion overlapping the bellows shape on the first surface of the base material is set to F3, the first surface of the base material The positions of the peaks and valleys appearing in the portion overlapping the bellows shape on the second surface located on the opposite side are the valleys and valleys appearing in the portion overlapping the bellows shape on the first surface of the base material It may be shifted by 0.1×F3 or more from the peak position.

Further, one embodiment of the present disclosure includes a first surface and a second surface located on the opposite side of the first surface, a base material having elasticity, and a base material located on the first surface side of the base material one wiring, and an expansion/contraction adjusting portion that overlaps the one wiring when viewed along the normal direction of the first surface of the base material, wherein the one wiring is the base material. A portion of the one wiring that overlaps the expansion/contraction adjusting portion, and has a bellows shape in which peaks and valleys in the normal direction of the first surface repeatedly appear along the in-plane direction of the first surface of the base material. is different from the period of the bellows shape of the portion that does not overlap with the expansion/contraction adjusting portion.

In the wiring board according to an embodiment of the present disclosure, the expansion/contraction adjusting portion may have a larger elastic modulus than the elastic modulus of the base material.

Further, one embodiment of the present disclosure includes a first surface and a second surface located on the opposite side of the first surface, a base material having elasticity, and a base material located on the first surface side of the base material and a plurality of wirings, wherein the plurality of wirings includes a first wiring and a second wiring, and when viewed along the normal direction of the first surface of the base material, the first wiring The wiring has a first wiring expansion/contraction adjusting portion that overlaps with the first wiring, the second wiring has a second wiring expansion/contraction adjusting portion that overlaps with the second wiring, and the first wiring and the second wiring The wiring No. 2 has a bellows shape in which peaks and valleys in the normal direction of the first surface of the base material repeatedly appear along the in-plane direction of the first surface of the base material, and wherein the period of the bellows shape in the portion overlapping with the first wiring expansion/contraction adjusting portion is larger than the period of the bellows shape in the portion not overlapping with the first wiring expansion/contraction adjusting portion, and in the second wiring, The period of the bellows shape in the portion overlapping with the second wiring expansion/contraction adjusting portion is larger than the period of the bellows shape in the portion not overlapping with the second wiring expansion/contraction adjusting portion, and the portion overlapping with the first wiring expansion/contraction adjusting portion is longer. In the wiring board, the period of the bellows shape of the first wiring is larger than the period of the bellows shape of the second wiring in the portion overlapping with the second wiring expansion/contraction adjusting portion.

In the wiring board according to one embodiment of the present disclosure, the first wiring expansion/contraction adjusting portion and the second wiring expansion/contraction adjusting portion may have a larger elastic modulus than the elastic modulus of the base material.

The wiring board according to one embodiment of the present disclosure may further include a supporting base positioned between the wiring and the first surface of the base and supporting the wiring.

In the wiring board according to one embodiment of the present disclosure, the support base may have an elastic modulus larger than that of the base.

In the wiring board according to the embodiment of the present disclosure, the structure of the wiring formed on the stretchable base material is provided with a portion having a weak mechanical strength against deformation. Wiring deterioration occurs first in the weak portion.
Degradation of a specific wiring having such a weak portion causes disconnection or an increase in resistance value in a circuit related to this wiring, and the user can be notified of the deterioration of the wiring.
Therefore, it is possible to prevent the continuation of use of the electronic device without noticing the deterioration of the wiring, and it is possible to prevent the function of the electronic device from being impaired and accidents to occur.

1 is a diagram showing an example of a wiring board according to a first embodiment of the present disclosure, where (a) is a plan view and (b) is a cross-sectional view taken along the line AA of (a); FIG. 4 shows another example of the wiring board according to the first embodiment of the present disclosure; A diagram showing an example of a wiring board according to a second embodiment of the present disclosure A diagram showing an example of a wiring board according to a third embodiment of the present disclosure A diagram showing an example of a wiring board according to a fourth embodiment of the present disclosure FIG. 12A is a plan view showing an example of a wiring board according to a fifth embodiment of the present disclosure, and FIG. FIG. 12 is a diagram showing an example of a wiring board according to a sixth embodiment of the present disclosure, where (a) is a plan view and (b) is a cross-sectional view taken along the line CC of (a); FIG. 12 is a diagram showing an example of a wiring board according to a seventh embodiment of the present disclosure, (a) is a plan view, (b) is a cross-sectional view along line DD of (a), and (c) is a diagram of (a). EE line sectional view FIG. 12A is a diagram showing an example of a wiring board according to an eighth embodiment of the present disclosure, where (a) is a plan view and (b) is a cross-sectional view taken along line FF of (a); FIG. 13A is a plan view showing another example of the wiring board according to the eighth embodiment of the present disclosure, and FIG. FIG. 12 is a diagram showing an example of a wiring board according to a ninth embodiment of the present disclosure, (a) is a plan view, (b) is a cross-sectional view taken along the line HH of (a), and (c) is a diagram of (a). II line sectional view FIG. 20 is a diagram showing an example of a wiring board according to a tenth embodiment of the present disclosure, where (a) is a plan view and (b) is a cross-sectional view taken along line JJ of (a); 11A and 11B are diagrams showing an example of a wiring board according to an eleventh embodiment of the present disclosure, where (a) is a plan view, (b) is a cross-sectional view along line KK of (a), and (c) is a diagram of (a). LL line sectional view FIG. 12A is a plan view showing an example of a wiring board according to a twelfth embodiment of the present disclosure, and FIG. 14A and 14B are diagrams for explaining an example of a method for manufacturing the wiring board; FIG. 20 is a diagram showing an example of a wiring board according to a thirteenth embodiment of the present disclosure, where (a) is a plan view and (b) is a cross-sectional view taken along line NN of (a); 16A and 16B are diagrams for explaining an example of a method for manufacturing the wiring board; FIG. 13B is a diagram showing another example of the wiring board according to the thirteenth embodiment of the present disclosure;

Hereinafter, a configuration of a wiring board and a method for manufacturing the same according to embodiments of the present disclosure will be described in detail with reference to the drawings.

<First Embodiment>
First, a first embodiment of the present disclosure will be described with reference to FIGS. 1 and 2. FIG.
FIG. 1 is a diagram showing an example of a wiring board according to the first embodiment of the present disclosure, (a) is a plan view, and (b) is a cross-sectional view taken along line AA of (a). Moreover, FIG. 2 is a diagram showing another example of the wiring board according to the first embodiment of the present disclosure.

The wiring board 10 shown in FIG. 1 includes at least a base material 20 and wiring 30 . Each component of the wiring board 10 will be described below.

[Base material]
The base material 20 is a member configured to have elasticity. The base material 20 includes a first surface 21 located on the wiring 30 side and a second surface 22 located on the opposite side of the first surface 21 . In the following description, viewing the wiring board 10 or components of the wiring board 10 along the normal direction of the first surface 21 as shown in FIG. A tensile stress is applied to the base material 20, for example, in the X direction in the figure.

The thickness of the base material 20 is, for example, 10 μm or more and 10 mm or less, more preferably 20 μm or more and 3 mm or less. By setting the thickness of the base material 20 to 10 μm or more, the durability of the base material 20 can be ensured. Also, by setting the thickness of the base material 20 to 10 mm or less, the wearing comfort of the wiring board 10 can be ensured. Note that if the thickness of the base material 20 is too small, the stretchability of the base material 20 may be impaired.

The stretchability of the base material 20 refers to the ability of the base material 20 to expand and contract, that is, the ability to extend from the normal non-stretched state, and the ability to restore when released from the stretched state. It refers to the nature of being able to The non-stretched state is the state of substrate 20 when no tensile stress is applied. In this embodiment, the stretchable substrate can preferably be stretched by 1% or more from an unstretched state without breaking, more preferably by 20% or more, and even more preferably by 75%. It can be extended more than By using the base material 20 having such ability, the wiring board 10 can have elasticity as a whole. Furthermore, the wiring board 10 can be used in products and applications that require high expansion and contraction, such as attachment to a part of the body such as a human arm.

An example of a parameter representing the stretchability of the base material 20 is the elastic modulus of the base material 20 . The elastic modulus of the base material 20 is, for example, 10 MPa or less, more preferably 1 MPa or less. By using the base material 20 having such an elastic modulus, the wiring board 10 as a whole can be made stretchable.

As a method of calculating the elastic modulus of the base material 20, a method of performing a tensile test in accordance with JIS K6251 using a sample of the base material 20 can be adopted. A method of measuring the elastic modulus of a sample of the base material 20 by a nanoindentation method in compliance with ISO14577 can also be adopted. A nanoindenter can be used as a measuring instrument used in the nanoindentation method. As a method of preparing a sample of the base material 20, a method of taking out a part of the base material 20 from the wiring board 10 as a sample and a method of taking out a part of the base material 20 before forming the wiring board 10 as a sample are considered. be done. In addition, as a method of calculating the elastic modulus of the base material 20, adopting a method of analyzing the materials constituting the base material 20 and calculating the elastic modulus of the base material 20 based on an existing material database. can also In addition, the elastic modulus in this application is an elastic modulus in a 25 degreeC environment.

Another example of the parameter representing the stretchability of the base material 20 is the bending rigidity of the base material 20 . The flexural rigidity is the product of the geometrical moment of inertia of the target member and the elastic modulus of the material constituting the target member, and the unit is N·m ² or Pa·m ⁴ . The geometrical moment of inertia of the base material 20 is calculated based on a cross section obtained by cutting a portion of the base material 20 that overlaps the wiring 30 with a plane perpendicular to the expansion/contraction direction of the wiring board 10 .

Examples of materials that constitute the base material 20 include elastomers. Also, as the material of the base material 20, for example, cloth such as woven fabric, knitted fabric, and non-woven fabric can be used. As the elastomer, general thermoplastic elastomers and thermosetting elastomers can be used. Specifically, polyurethane-based elastomers, styrene-based elastomers, nitrile-based elastomers, olefin-based elastomers, vinyl chloride-based elastomers, ester-based elastomers, Amide elastomers, 1,2-BR elastomers, fluorine elastomers, silicone rubbers, urethane rubbers, fluorine rubbers, polybutadiene, polyisobutylene, polystyrene butadiene, polychloroprene and the like can be used. Considering mechanical strength and abrasion resistance, it is preferable to use a urethane-based elastomer. Base material 20 may also contain silicone such as polydimethylsiloxane. Silicone is excellent in heat resistance, chemical resistance, and flame resistance, and is preferable as a material for the base material 20 .

Further, when the wiring 30 described later has a bellows shape, a plurality of ridges and valleys arranged along the direction in which the wiring 30 extends also appears on the first surface 21 of the base material 20 . A plurality of ridges and troughs arranged along the direction in which the wiring 30 extends may also appear on the second surface 22 of .
Here, with respect to the peaks and valleys appearing on the first surface 21 of the substrate 20, the portions that are convex from the second surface 22 side of the substrate 20 toward the first surface 21 side are referred to as peaks. , the recessed portion is referred to as a valley portion.
In addition, the peaks and valleys appearing on the second surface 22 of the base material 20 are referred to as peaks when protruding from the first surface 21 side of the base material 20 toward the second surface 22 side, and are referred to as concave portions. A part which becomes is called a valley part.

(Contents of claim 15)
The amplitude of peaks and troughs appearing in the portion overlapping the accordion shape on the second surface 22 located on the opposite side of the first surface 21 of the base material 20 is It may be smaller than the amplitude of peaks and valleys appearing in the overlapping portion of the bellows shape.

In addition, the amplitude of peaks and troughs appearing in the portion overlapping the bellows shape on the second surface 22 located on the opposite side of the first surface 21 of the base material 20 is It may be less than or equal to 0.9 times the amplitude of peaks and troughs appearing in the overlapping portion of the bellows shape.

In addition, the period of peaks and troughs appearing in the portion of the second surface 22 opposite to the first surface 21 of the substrate 20 that overlaps the bellows shape is It may be larger than the period of peaks and valleys appearing in the overlapping portion of the bellows shape.

In addition, the period of peaks and troughs appearing in the portion of the second surface 22 opposite to the first surface 21 of the substrate 20 that overlaps the bellows shape is It may be 1.1 times or more the period of the peaks and valleys appearing in the portion overlapping the bellows shape.

In addition, the positions of the peaks and valleys appearing in the portion overlapping the bellows shape on the second surface 22 located on the opposite side of the first surface 21 of the base material 20 are the The positions of the peaks and valleys appearing in the portion overlapping the bellows shape may be displaced.

Further, when the period of peaks and troughs appearing in the portion of the first surface 21 of the substrate 20 that overlaps the bellows shape is set to F3, the second surface located on the opposite side of the first surface 21 of the substrate 20 is F3. The positions of peaks and troughs appearing in the portion overlapping the accordion shape in 22 are 0.1× from the positions of peaks and valleys appearing in the portion overlapping the accordion shape in first surface 21 of base material 20. The deviation may be F3 or more.

[wiring]
The wiring 30 is a member having conductivity and having an elongated shape in plan view. In the wiring board 10 shown in FIG. 1, one wiring 30 extends in the direction in which the base material 20 extends (the X direction in the figure), and the width of the wiring in the wiring 30 is partially different. More specifically, the wiring 30 has a narrow portion 31, and the width (W2) of the narrow portion 31 is smaller than the width (W1) of the other portion of the wiring 30. As shown in FIG. That is, the narrow portion 31 (more specifically, the boundary portion where the wiring width changes from W1 to W2) is a portion having weaker mechanical strength against expansion and contraction of the base material 20 than other portions of the wiring 30. Become.

Therefore, in the wiring board 10, as the base material 20 expands and contracts, the wiring deterioration first occurs in the narrow portion 31 of the wiring 30 (more specifically, the boundary portion where the width of the wiring changes from W1 to W2). become. Deterioration of the wiring 30 causes disconnection or an increase in resistance value in a circuit related to the wiring 30, and the deterioration of the wiring can be notified to the user. For example, by the action of a circuit related to the wiring 30, a specific function of the electronic device provided with the wiring board 10 is stopped, or conversely, a specific function is activated, thereby notifying the user of the deterioration of the wiring of the electronic device. be able to.

An example of stopping a specific function of an electronic device as described above is turning off a lamp indicating safety. Examples of activation of a specific function include a warning lamp, a warning sound, transmission of e-mail, and the like.

In the example shown in FIG. 1, the narrow portion 31 has a rectangular shape with a width W2 in plan view, but the shape of the narrow portion 31 is not limited to this in the present embodiment. In the present embodiment, the width of the narrow portion 31 is partially smaller than that of the other portions, so that the narrow portion 31 has a mechanical strength against expansion and contraction of the base material 20 compared to other portions of the wiring 30. is a weak point.

For example, as shown in FIG. 2A, a curved concave portion is formed in the width direction (the Y direction in the drawing) of the wiring 30, and the minimum width (W2) of the narrow portion 31 is the same as that of the other portion of the wiring 30. may be smaller than the width (W1) of .
Further, as shown in FIG. 2B, a triangular recess (notch) is formed in the width direction (the Y direction in the drawing) of the wiring 30, and the minimum width (W2) of the narrow portion 31 is the width of the wiring. It may be in a form that is smaller than the width (W1) of the other portion of 30 .

In this embodiment, the wiring 30 is positioned on the first surface 21 side of the base material 20 . As shown in FIG. 1, the wiring 52 may be in contact with the first surface 21 of the substrate 20 . Although not shown, another member may be interposed between the second surface 22 of the base material 20 and the wiring 30 .

A material that can follow the expansion and contraction of the base material 20 is used as the material of the wiring 30 . The material of the wiring 30 itself may or may not have elasticity.

For example, the wiring 30 may be a horseshoe-shaped wiring (see Patent Document 1) in which a curved pattern in plan view repeatedly appears along the in-plane direction of the first surface 21 of the base 20 , or By forming a bellows-shaped wiring (see Patent Document 2) in which peaks and valleys in the normal direction of the first surface 21 appear repeatedly along the in-plane direction of the first surface 21 of the base material 20, the material of the wiring 30 may itself be inelastic.

In other words, for example, the form of the wiring 30 having the horseshoe shape is configured to be stretchable in one direction along the in-plane direction of the first surface 21 of the base material 20. It has a curvilinear expansion/contraction pattern, and the expansion/contraction pattern includes a first curved pattern portion that changes direction from one side to the other side in a direction that intersects with the expansion/contraction direction, and a first curved pattern portion that continues from the first curved pattern portion. It is possible to adopt a continuous pattern in which the second curved pattern portion in the opposite direction that changes the direction from the other to the one direction is alternately and repeatedly provided at predetermined intervals in the stretching direction.

It should be noted that the wiring 30 may be made of a material that itself has elasticity, and the wiring 30 may be a horseshoe-shaped wiring or a bellows-shaped wiring as described above.

Examples of materials that can be used for the wiring 30 and that do not have elasticity per se include metals such as gold, silver, copper, aluminum, platinum, and chromium, and alloys containing these metals. If the material of the wiring 52 itself does not have stretchability, a metal film can be used as the wiring 30 .

When the material itself used for the wiring 30 has elasticity, the elasticity of the material is the same as that of the base material 20, for example. Examples of materials that can be used for the wiring 30 and that have elasticity in themselves include a conductive composition containing conductive particles and an elastomer.
The conductive particles may be those that can be used for wiring, and examples thereof include particles of gold, silver, copper, nickel, palladium, platinum, carbon, and the like. Among them, silver particles are preferably used.

Preferably, the wiring 30 comprises a structure that is resistant to deformation. For example, line 30 has a base material and a plurality of conductive particles dispersed within the base material. In this case, by using a deformable material such as resin as the base material, the wiring 30 can also be deformed according to the expansion and contraction of the base material 20 . In addition, the conductivity of the wiring 30 can be maintained by setting the distribution and shape of the conductive particles so that the contact between the plurality of conductive particles is maintained even when deformation occurs. .

Common thermoplastic elastomers and thermosetting elastomers can be used as the material constituting the base material of the wiring 30. Examples include styrene elastomers, acrylic elastomers, olefin elastomers, urethane elastomers, silicone rubbers, Urethane rubber, fluororubber, nitrile rubber, polybutadiene, polychloroprene, and the like can be used. Among them, resins and rubbers containing urethane-based or silicone-based structures are preferably used in terms of stretchability and durability. Also, as a material forming the conductive particles of the wiring 30, particles such as silver, copper, gold, nickel, palladium, platinum, and carbon can be used. Among them, silver particles are preferably used.

The thickness of the wiring 30 may be any thickness that can withstand expansion and contraction of the base material 20, and is appropriately selected according to the material of the wiring 30 and the like.
For example, when the material of the wiring 30 does not have stretchability, the thickness of the wiring 30 can be in the range of 25 nm or more and 100 μm or less, preferably 50 nm or more and 50 μm or less, and 100 nm or more and 5 μm. It is more preferable to be within the following range.
Further, when the material of the wiring 30 has elasticity, the thickness of the wiring 30 can be in the range of 5 μm or more and 60 μm or less, preferably in the range of 10 μm or more and 50 μm or less, and 20 μm or more and 40 μm or less. It is more preferable to be within the range.

The width (W1) of the wiring 30 and the width (W2) of the narrow portion 31 are appropriately selected according to the resistance value required for the wiring 30 . Furthermore, the width (W2) of the narrow portion 31 is appropriately selected to serve as an indicator for measuring the degree of deterioration of the wiring 30 due to expansion and contraction. The circuit related to the wiring 30 is for notifying the user that the wiring 30 has been disconnected or the resistance value has increased. That is, the circuit associated with the wiring 30 can be made independent of the circuits associated with the other wirings of the wiring board 10 .

In this embodiment, the width (W1) of the wiring 30 is, for example, 1 μm or more, preferably 50 μm or more. Also, the width (W1) of the wiring 30 is, for example, 10 mm or less, preferably 1 mm or less. The width (W2) of the narrow portion 31 is, for example, 10% or more of the width (W1) of the wiring 30 and 90% or less of the width (W1) of the wiring 30 . Preferably, the width (W2) of the narrow portion 31 is 20% or more and 80% or less of the width (W1) of the wiring 30 .

A method for forming the wiring 30 is appropriately selected according to the material and the like. For example, a method of forming a metal film on the base material 20 or a support base material 410 to be described later by a vapor deposition method, a sputtering method, or the like and then patterning the metal film by a photolithography method can be used. In addition, when the material of the wiring 30 itself has stretchability, for example, the conductive composition containing the above-described conductive particles and elastomer is patterned on the base material 20 or the support base material 410 by a general printing method. a method of printing to Among these methods, the printing method, which has high material efficiency and can be manufactured at low cost, can be preferably used.

<Second embodiment>
Next, a second embodiment of the present disclosure will be described.
A wiring board according to a second embodiment of the present disclosure includes a first surface and a second surface located opposite to the first surface, a stretchable base material, and the first surface of the base material. and a plurality of wirings positioned on the same side, the plurality of wirings including a first wiring and a second wiring, the first wiring having a width of the wiring in the first wiring that is partially equal to the width of the wiring in the first wiring. The second wiring has a second wiring narrow portion in which the width of the wiring in the second wiring is partially narrow, and the width of the first wiring narrow portion is The wiring substrate has a width smaller than that of the second wiring narrow portion.

FIG. 3 is a plan view showing an example of a wiring board according to a second embodiment of the present disclosure; FIG. The second embodiment of the present disclosure differs from the above-described first embodiment of the present disclosure (see FIG. 1) in the number of wirings and the planar shape of the narrow portion of each wiring. Elements can be the same.

For example, a wiring board 40 shown in FIG. 3 includes a base material 20 having elasticity and a plurality of wirings (first wirings 50 and second wirings 60) located on the first surface 21 side of the base material 20. ing.
The first wiring 50 has a first wiring narrow portion 51 in which the width of the wiring in the first wiring 50 is partially small. That is, in the wiring substrate 40 shown in FIG. 3 , the width (W4) of the first wiring narrow portion 51 is smaller than the width (W3) of the other portions of the first wiring 50 .
Further, the second wiring 60 has a second wiring narrow portion 61 in which the width of the wiring in the second wiring 60 is partially small. That is, in the wiring board 40 shown in FIG. 3 , the width (W5) of the second wiring narrow portion 61 is smaller than the width (W3) of the other portion of the second wiring 60 .
The width (W4) of the first wiring narrow portion 51 is smaller than the width (W5) of the second wiring narrow portion 61 .

3 can be the same material as the wiring 30 in the above-described first embodiment of the present disclosure (see FIG. 1). can also be formed in the same manner as the wiring 30 .

Also in the present embodiment, as in the first embodiment of the present disclosure described above, the wirings 50 and 60 may be horseshoe-shaped wirings or bellows-shaped wirings.

Since the wiring substrate 40 has the above-described structure, as the base material 20 expands and contracts, wiring deterioration first occurs in the first narrow wiring portion 51 of the first wiring 50, and then the second narrow wiring portion 51 deteriorates. Wiring deterioration occurs in the second wiring narrow portion of the wiring 60 . That is, it is possible to cause wiring deterioration in stages. Therefore, the user can know step by step the wiring deterioration of the electronic device including the wiring substrate 40 .
For example, in an electronic device including the wiring board 40, it is possible to issue a first warning due to wiring deterioration of the first wiring 50 and to issue a second warning due to wiring deterioration of the second wiring 60. can.

Although FIG. 3 illustrates the wiring substrate 40 having two wires, the first wire 50 and the second wire 60, the second embodiment of the present disclosure is not limited to this.
For example, the wiring board may have three or more wires each having a narrow portion whose width is partially small, and the narrow portion of each wire may have a different width for each wire.
With such a configuration, the wiring deteriorates in order from the wiring having the narrow portion with the smaller width, so that the user can know the deterioration of the wiring of the electronic device provided with this wiring substrate more finely and step by step. .

<Third Embodiment>
Next, a third embodiment of the present disclosure will be described.
A wiring board according to a third embodiment of the present disclosure includes a first surface and a second surface located opposite to the first surface, a stretchable base material, and the first surface of the base material. and one wiring located on the side of the substrate, and in the in-plane direction of the first surface of the base, the one wiring includes a first direction portion extending in the first direction and a second direction portion extending from the first direction to the second direction. and a second direction portion extending in the second direction, wherein the width of the wire in the first direction portion and the width of the wire in the second direction portion are larger The width of the wiring board is small.

FIG. 4 is a plan view showing an example of a wiring board according to a third embodiment of the present disclosure; FIG. The third embodiment of the present disclosure differs from the above-described first embodiment of the present disclosure (see FIG. 1) in terms of the planar form of wiring, and other components may be the same.
Therefore, in FIG. 4, only the shape of the characteristic portion of the wiring in plan view is shown, and the illustration of other components is omitted.

For example, in the example shown in FIG. 4, the wiring 70 has a first direction portion 71 extending in a first direction (the X direction shown in the drawing) and bending from the first direction to the second direction (the Y direction shown in the drawing). It has a curved portion 72 and a second direction portion 73 extending in two directions. The width (W7) of the wiring in the curved portion 72 is smaller than the width (W6) of the wiring in the first direction portion 71 and the width (W6) of the wiring in the second direction portion 73 .

The material of the wiring 70 shown in FIG. 4 can also be the same material as the wiring 30 in the above-described first embodiment of the present disclosure (see FIG. 1). It can be formed in a similar way.

Because of the above configuration, in the wiring board having the wiring 70 , the wiring is formed first at the curved portion 72 of the wiring 70 (more specifically, at the portion where the wiring has the smallest width) as the base material expands and contracts. deterioration will occur. Degradation of the wiring 70 causes disconnection or an increase in resistance value in a circuit related to the wiring 70, and the deterioration of the wiring can be notified to the user.

In the example shown in FIG. 4, the wiring 70 extends from the first direction (the X direction shown in the drawing) to the second direction (the Y direction shown in the drawing) at an angle of 90 degrees through the curved portion 72 . Although redirected, the third embodiment of the present disclosure is not so limited.
In this embodiment, it is sufficient that the width of the wiring in the curved portion 72 is smaller than the width of the wiring in the first direction portion 71 and the width of the wiring in the second direction portion 73. The angle formed by the two directions may be less than 90 degrees (acute angle) or 90 degrees or more (obtuse angle).

Further, in the example shown in FIG. 4, the outer shape of the curved portion 72 is straight, but in the present embodiment, the outer shape of the curved portion 72 may include curved lines.

Also in the present embodiment, as in the first embodiment of the present disclosure described above, the wiring 70 may be a horseshoe-shaped wiring or a bellows-shaped wiring.

<Fourth Embodiment>
Next, a fourth embodiment of the present disclosure will be described.
A wiring board according to a fourth embodiment of the present disclosure includes a first surface and a second surface located on the opposite side of the first surface, a stretchable base material, and the first surface of the base material. and a plurality of wirings positioned on the side of the substrate, the plurality of wirings including a first wiring and a second wiring, and in the in-plane direction of the first surface of the base material, the first wiring is , a first direction portion extending in a first direction, a first wiring bending portion bending from the first direction to a second direction, and a second direction portion extending in the second direction, wherein the first direction portion The width of the wiring at the first wiring curved portion is smaller than the width of the wiring at the first wiring bending portion and the width of the wiring at the second direction portion, and the second wiring includes a third direction portion extending in the third direction, and the width of the wiring at the second direction portion. It has a second wire bending portion that bends from three directions to a fourth direction, and a fourth direction portion that extends in the fourth direction, wherein the width of the wire in the third direction portion and the width of the wire in the fourth direction portion In the wiring board, the width of the wiring in the second wiring curved portion is smaller than that in the second wiring curved portion, and the width of the wiring in the first wiring curved portion is smaller than the width of the wiring in the second wiring curved portion.

FIG. 5 is a plan view showing an example of a wiring board according to a fourth embodiment of the present disclosure; FIG. 5(a) shows a planar configuration of the first wiring 80, and FIG. 5(b) shows a planar configuration of the second wiring 90. As shown in FIG. The first wiring 80 and the second wiring 90 are two wirings among a plurality of wirings that one wiring substrate has, and are located on the first surface side of one base material.

Note that the fourth embodiment of the present disclosure differs from the above-described third embodiment of the present disclosure (see FIG. 4) in the number of wirings and the planar shape of the curved portion of each wiring. Elements can be the same.

Also in the present embodiment, as in the above-described first embodiment of the present disclosure, the first wiring 80 and the second wiring 90 may be horseshoe-shaped wiring or bellows-shaped wiring.

For example, in the example shown in FIG. 5, the first wiring 80 has a first direction portion 81 extending in the first direction (the X direction in the drawing) and a first direction portion 81 extending from the first direction to the second direction (the Y direction in the drawing). It has a curved first wire bending portion 82 and a second direction portion 83 extending in the second direction. The width (W9) of the wire in the first wire curved portion 82 is smaller than the width (W8) of the wire in the first direction portion 81 and the width (W8) of the wire in the second direction portion 83 .
The second wiring 90 has a third direction portion 91 extending in the third direction (X direction in the drawing) and a second wiring curved portion 92 bending from the third direction to the fourth direction (Y direction in the drawing). and a fourth direction portion 93 extending in the fourth direction. The width (W10) of the wire in the second wire curved portion 92 is smaller than the width (W8) of the wire in the third direction portion 91 and the width (W8) of the wire in the fourth direction portion 93 .
The width (W9) of the wiring in the first wiring curved portion 82 is smaller than the width (W10) of the wiring in the second wiring curved portion 92 .

The same material as the wiring 30 in the above-described first embodiment of the present disclosure (see FIG. 1) can be used for the wirings 80 and 90 shown in FIG. can also be formed in the same manner as the wiring 30 .

Due to the above configuration, in the wiring board having the wiring 80 and the wiring 90, wiring deterioration first occurs in the first wiring curved portion 82 of the first wiring 80 as the base material 20 expands and contracts. Next, wiring deterioration occurs in the second wiring curved portion 92 of the second wiring 90 . That is, it is possible to cause wiring deterioration in stages. Therefore, the user can know the wiring deterioration of the electronic device provided with the wiring board having the wiring 80 and the wiring 90 in stages.
For example, wiring deterioration of the first wiring 80 may cause a first warning, and wiring deterioration of the second wiring 90 may cause a second warning.

Note that although FIG. 5 illustrates a configuration having two wirings, the first wiring 80 and the second wiring 90, the fourth embodiment of the present disclosure is not limited to this.
For example, the wiring board may have three or more wirings having a curved portion with a partially narrow width, and the width of the curved portion of each wiring may be different for each wiring.
With such a configuration, the wiring deteriorates in order from the wiring having the curved portion with the smaller width, so that the user can know the deterioration of the wiring of the electronic device provided with this wiring board in a more detailed and stepwise manner. .

<Fifth Embodiment>
Next, a fifth embodiment of the present disclosure will be described.
A wiring board according to a fifth embodiment of the present disclosure includes a first surface and a second surface located opposite to the first surface, a stretchable base material, and the first surface of the base material. and one wiring located on the side of the substrate, wherein the one wiring is partially different in material constituting the wiring.

FIG. 6 is a diagram showing an example of a wiring board according to a fifth embodiment of the present disclosure, where (a) is a plan view and (b) is a cross-sectional view taken along line BB of (a).
The fifth embodiment of the present disclosure differs from the above-described first embodiment of the present disclosure (see FIG. 1) in wiring configuration, and other components may be the same.

For example, a wiring board 110 shown in FIG. 6 includes a base material 20 having elasticity and one wiring 120 positioned on the first surface 21 side of the base material 20 .
The wiring 120 is mostly a first material portion 121 made of a first material and partially has a second material portion 122 made of a second material.

Since the wiring substrate 110 has the above-described configuration, the second material portion 122 (more specifically, the first material portion 121 and the second material portion 121 of the wiring 120 expand and contract) as the base material 20 expands and contracts. 122), wiring deterioration occurs first. Deterioration of the wiring 120 causes disconnection or an increase in resistance value in a circuit related to the wiring 120, and the deterioration of the wiring can be notified to the user.

The same material as the wiring 30 in the above-described first embodiment of the present disclosure (see FIG. 1) can be used for the first material forming the first material portion 121 in the wiring 120, and the first material The portion 121 can also be formed in the same manner as the wiring 30 .

The second material forming the second material portion 122 in the wiring 120 can be used as long as it has conductivity and is different from the first material forming the first material portion 121 .

For example, non-stretchable materials include metals such as gold, silver, copper, aluminum, platinum, and chromium, and alloys containing these metals.
Further, examples of stretchable materials include conductive compositions containing conductive particles and an elastomer.
The conductive particles may be those that can be used for wiring, and examples thereof include particles of gold, silver, copper, nickel, palladium, platinum, carbon, and the like. Among them, silver particles are preferably used.
As the elastomer, general thermoplastic elastomers and thermosetting elastomers can be used. , polybutadiene, polychloroprene, and the like can be used. Among them, resins and rubbers containing urethane-based or silicone-based structures are preferably used in terms of stretchability and durability.

A method for forming the second material portion 122 in the wiring 120 is appropriately selected according to the material and the like. For example, there is a method of forming a metal film by a vapor deposition method, a sputtering method, or the like, and then patterning the metal film by a photolithography method. Moreover, when the second material has stretchability, for example, a method of printing a conductive composition containing the above conductive particles and an elastomer in a pattern by a general printing method can be used. Among these methods, the printing method, which has high material efficiency and can be manufactured at low cost, can be preferably used.
Generally, the second material portion 122 of the wiring 120 is formed using the same method as the method of forming the first material portion 121 of the wiring 120 .

The elastic modulus value of the second material portion 122 made of the second material is preferably greater than the elastic modulus value of the first material portion 121 made of the first material.
When the elastic modulus of the second material portion 122 is larger than the elastic modulus of the first material portion 121 , the second material portion 122 is more susceptible to expansion and contraction of the base material 20 than the first material portion 121 . , it tends to be difficult to follow and deform, and wiring deterioration tends to occur in the second material portion 122 (more specifically, the boundary portion between the first material portion 121 and the second material portion 122). is.

As a method for making the elastic modulus of the second material part 122 larger than that of the first material part 121, for example, the first material and the second material are mixed with a conductive material containing conductive particles and an elastomer. There is a method of forming a conductive composition so that the content ratio of the elastomer to the conductive particles is higher in the first material than in the second material.

Note that the wiring substrate 110 may include a plurality of wirings having portions made of different materials for the wirings. For example, the wiring board 110 may have two or more wirings having portions (heterogeneous material portions) made of different materials constituting the wirings, and each wiring may have a different modulus of elasticity of the dissimilar material portion. .
With such a configuration, the wiring deteriorates in order from the wiring having the dissimilar material portion with the larger elastic modulus, so that the user can know the deterioration of the wiring of the electronic device provided with this wiring substrate more finely and step by step. can be done.

Also in the present embodiment, as in the above-described first embodiment of the present disclosure, the form of the wiring may be a horseshoe-shaped wiring or a bellows-shaped wiring.

<Sixth Embodiment>
Next, a sixth embodiment of the present disclosure will be described.
A wiring board according to a sixth embodiment of the present disclosure includes a first surface and a second surface located on the opposite side of the first surface, a stretchable base material, and the first surface of the base material. and one wiring located on the side, wherein the thickness of the wiring in the one wiring is partially different.

7A and 7B are diagrams showing an example of a wiring board according to a sixth embodiment of the present disclosure, where (a) is a plan view and (b) is a sectional view taken along line CC of (a).
It should be noted that the sixth embodiment of the present disclosure differs from the first embodiment of the present disclosure (see FIG. 1) in the wiring configuration, and the other components may be the same.

For example, a wiring board 130 shown in FIG. 7 includes a base material 20 having elasticity and one wiring 140 positioned on the first surface 21 side of the base material 20 . The wiring 140 has a form in which the thickness of the wiring is partially different. More specifically, the wiring 140 has a wiring thin portion 141 , and the thickness (T2) of the wiring thin portion 141 is smaller than the thickness (T1) of the other portion of the wiring 140 . That is, the wiring thin portion 141 (more specifically, the boundary portion where the wiring thickness changes from T1 to T2) has weaker mechanical strength against expansion and contraction of the base material 20 than other portions of the wiring 140. become part.

Due to the above configuration, in the wiring board 130, the wiring thin portion 141 of the wiring 140 (more specifically, the boundary portion where the wiring thickness changes from T1 to T2) accompanies expansion and contraction of the base material 20. In this case, wiring deterioration occurs first. Degradation of the wiring 140 causes disconnection or an increase in resistance value in a circuit related to the wiring 140, and the deterioration of the wiring can be notified to the user.

The material of the wiring 140 can be the same material as that of the wiring 30 in the above-described first embodiment of the present disclosure (see FIG. 1). can be formed.
For example, in the method of forming the wiring 140 by pattern-printing a conductive composition containing conductive particles and an elastomer, the thickness of the wiring thin portion 141 is T2, and the thickness of the other portion of the wiring 140 is can be T1.

Also in the present embodiment, as in the above-described first embodiment of the present disclosure, the form of the wiring may be a horseshoe-shaped wiring or a bellows-shaped wiring.

<Seventh Embodiment>
Next, a seventh embodiment of the present disclosure will be described.
A wiring board according to a seventh embodiment of the present disclosure includes a first surface and a second surface located on the opposite side of the first surface, a stretchable base material, and the first surface of the base material. and a plurality of wirings positioned at the same side, the plurality of wirings including a first wiring and a second wiring, the first wiring having a thickness of a portion of the wiring in the first wiring. and the second wiring has a second wiring thin portion in which the thickness of the wiring in the second wiring is partially small, and the thickness of the first wiring thin portion is The width of the wiring board is smaller than the thickness of the second wiring thin portion.

FIG. 8 is a diagram showing an example of a wiring board according to the seventh embodiment of the present disclosure, (a) is a plan view, (b) is a cross-sectional view along line DD of (a), and (c) is a It is a cross-sectional view taken along line EE of (a). The seventh embodiment of the present disclosure differs from the above-described sixth embodiment of the present disclosure (see FIG. 7) in the number of wirings and the cross-sectional shape of the wiring thin portion of each wiring. The components may be the same.

For example, a wiring board 150 shown in FIG. 8 includes a base material 20 having elasticity and a plurality of wirings (first wirings 160 and second wirings 170) located on the first surface 21 side of the base material 20. ing.
The first wiring 160 has a first wiring thin portion 161 in which the thickness of the wiring in the first wiring 160 is partially reduced. That is, as shown in FIG. 8B, the thickness (T4) of the first wiring thin portion 161 is smaller than the thickness (T3) of the other portion of the first wiring 160. As shown in FIG.
In addition, the second wiring 170 has a second wiring thin portion 171 in which the thickness of the wiring in the second wiring 170 is partially thin. That is, as shown in FIG. 8C, the thickness (T5) of the second wiring thin portion 171 is smaller than the thickness (T3) of the other portion of the second wiring 170. As shown in FIG.
The thickness (T4) of the first wiring thin portion 161 is smaller than the thickness (T5) of the second wiring thin portion 171. As shown in FIG.

8 can be the same material as the wiring 30 in the above-described first embodiment of the present disclosure (see FIG. 1). can also be formed in the same manner as the wiring 30 .
For example, in the method of forming the wirings 160 and 170 by pattern-printing a conductive composition containing conductive particles and an elastomer, the thickness of the first wiring thin portion 161 is set to T4, and the thickness of the wiring 160 is set to T4. can be T3. Similarly, the thickness of the second wiring thin portion 171 can be set to T5, and the thickness of the other portion of the wiring 170 can be set to T3.

Since the wiring substrate 150 has the above-described structure, as the base material 20 expands and contracts, wiring deterioration first occurs in the first wiring thin portion 161 of the first wiring 160, and then the second wiring thin portion 161 deteriorates. Wiring deterioration occurs in the second wiring thin portion 171 of the wiring 170 . That is, it is possible to cause wiring deterioration in stages. Therefore, the user can know the deterioration of the wiring of the electronic device including the wiring board 150 in stages.
For example, in an electronic device including the wiring board 150, it is possible to issue a first warning due to wiring deterioration of the first wiring 160 and to issue a second warning due to wiring deterioration of the second wiring 170. can.

Although FIG. 8 illustrates the wiring substrate 150 having two wirings, the first wiring 160 and the second wiring 170, the seventh embodiment of the present disclosure is not limited to this.
For example, the wiring board may have three or more wires each having a thin portion whose thickness is partially small, and the thickness of the thin portion of each wire may be different for each wire. .
With such a configuration, the wiring deterioration occurs in order from the wiring having the thinner portion with the smaller thickness, so that the user can know the wiring deterioration of the electronic device provided with this wiring substrate in more detail and step by step. I can.

Also in the present embodiment, as in the above-described first embodiment of the present disclosure, the form of the wiring may be a horseshoe-shaped wiring or a bellows-shaped wiring.

<Eighth Embodiment>
Next, an eighth embodiment of the present disclosure will be described with reference to FIGS. 9 and 10. FIG.
A wiring board according to an eighth embodiment of the present disclosure includes a first surface and a second surface located on the opposite side of the first surface, a stretchable base material, and the first surface of the base material. and a strength adjustment layer overlapping the one wiring when viewed along the normal direction of the first surface of the base material, the thickness of the strength adjustment layer are partially different wiring boards.

FIG. 9 is a diagram showing an example of a wiring board according to an eighth embodiment of the present disclosure, (a) is a plan view, and (b) is a cross-sectional view taken along line FF of (a). 10A and 10B are diagrams showing another example of the wiring board according to the eighth embodiment of the present disclosure, where (a) is a plan view and (b) is a cross-sectional view taken along line GG of (a). be.

For example, a wiring board 180 shown in FIG. 9 includes a base material 20 having elasticity and wiring 190 located on the first surface 21 side of the base material 20 .
Furthermore, the wiring board 180 includes a strength adjustment layer 200 that overlaps the wiring 190 when viewed along the normal direction of the first surface 21 of the base material 20, and the thickness of the strength adjustment layer 200 is partially reduced. are different.
More specifically, as shown in FIG. 9B, the wiring board 180 has the wiring 190 on the first surface 21 side of the base material 20, and the wiring 190 on the upper side of the wiring 190 (the Z direction side in the drawing). , has an intensity adjustment layer 200 . The strength adjustment layer 200 has a strength adjustment layer thin portion 201, and the thickness (T11) of the strength adjustment layer thin portion 201 is smaller than the thickness (T10) of the other portions of the strength adjustment layer 200. It's becoming
That is, the strength adjustment layer thin portion 201 (more specifically, the boundary portion where the thickness of the strength adjustment layer 200 changes from T10 to T11) responds to expansion and contraction of the base material 20 more than other portions of the strength adjustment layer 200. On the other hand, it becomes a portion with weak mechanical strength.
Therefore, even in the wiring 190, when viewed along the normal direction of the first surface 21 of the base material 20, the portion of the wiring 190 that overlaps with the strength adjustment layer thin portion 201 having the thickness T11 is not the wiring 190. (that is, the portion of the wiring 190 that overlaps with the strength adjustment layer 200 having a thickness of T10), the mechanical strength is weak against the expansion and contraction of the base material 20 .

Since the wiring board 180 has the above-described configuration, when the wiring board 180 is viewed along the normal direction of the first surface 21 of the base material 20 as the base material 20 expands and contracts, the strength adjustment layer thin portion 201 Wiring deterioration occurs first in the portion of the wiring 190 that overlaps with the . Degradation of the wiring 190 causes disconnection or an increase in resistance value in a circuit related to the wiring 190, and the deterioration of the wiring can be notified to the user.

The material of the wiring 190 can be the same material as that of the wiring 30 in the above-described first embodiment of the present disclosure (see FIG. 1). can be formed.

Also in the present embodiment, as in the above-described first embodiment of the present disclosure, the form of the wiring may be a horseshoe-shaped wiring or a bellows-shaped wiring.

[Strength adjustment layer]
The strength adjustment layer 200 is provided to reinforce the mechanical strength of the wiring 190 for the purpose of preventing disconnection or the like from occurring in the wiring 190 that deforms as the base material 20 expands and contracts.
The strength adjustment layer 200 is positioned so as to overlap at least the wiring 190 in plan view.
In the wiring substrate 180 shown in FIG. 9, the strength adjustment layer 200 is laminated on the first surface 21 side of the base material 20 above the wiring 190 (the Z direction side in the drawing). The strength adjustment layer 200 may be in contact with the wiring 190 , and another layer such as an insulating layer may be interposed between the wiring 190 and the strength adjustment layer 200 . Note that “overlapping” means that two components overlap when viewed along the normal direction of the first surface 21 of the base material 20 .
The width of the strength adjustment layer 200 (the length in the Y direction shown in FIG. 9A) may be the same as the width of the wiring 190 or may be larger than the width of the wiring 190 .

The strength adjustment layer 200 may be formed below the wiring 190 . For example, the wiring board 181 shown in FIG. there is

The strength adjustment layer 200 may have an elastic modulus greater than that of the base material 20 . The elastic modulus of the strength adjustment layer 200 is, for example, 10 GPa or more and 500 GPa or less, more preferably 1 GPa or more and 300 GPa or less.
If the elastic modulus of the strength adjustment layer 200 is too low, it may not be possible to prevent disconnection or the like from occurring in the wiring 190 that deforms as the base material 20 expands and contracts. Further, if the modulus of elasticity of the strength adjustment layer 200 is too high, the strength adjustment layer 200 may suffer structural destruction such as cracks and cracks when the base material 20 expands and contracts. The elastic modulus of the strength adjustment layer 200 may be 1.1 times or more and 5000 times or less, more preferably 10 times or more and 3000 times or less, that of the base material 20 .

A method for calculating the elastic modulus of the strength adjustment layer 200 is appropriately determined according to the form of the strength adjustment layer 200 . For example, the method for calculating the elastic modulus of the strength adjustment layer 200 may be the same as or different from the method for calculating the elastic modulus of the base material 20 in the above-described first embodiment of the present disclosure. For example, as a method of calculating the elastic modulus of the strength adjustment layer 200, a method of performing a tensile test in accordance with ASTM D882 using a sample of the strength adjustment layer 200 can be adopted.

When the elastic modulus of the strength adjusting layer 200 is larger than that of the base material 20, a metallic material can be used as the material forming the strength adjusting layer 200. FIG. Examples of metal materials include copper, aluminum, stainless steel, and the like. In addition, as materials constituting the strength adjustment layer 200, general thermoplastic elastomers, acrylic, urethane, epoxy, polyester, epoxy, vinyl ether, polyene/thiol or silicone oligomers and polymers can be used. etc. may be used. When the material constituting the strength adjustment layer 200 is these resins, the strength adjustment layer 200 may have transparency. In addition, the intensity adjustment layer 200 may have a light shielding property, for example, a property of shielding ultraviolet rays. For example, intensity adjustment layer 200 may be black. Also, the color of the intensity adjustment layer 200 and the color of the substrate 20 may be the same. The thickness of the strength adjustment layer 200 is, for example, 1 μm or more and 3 mm or less, more preferably 10 μm or more and 500 μm or less.

The properties of the strength adjustment layer 200 may be represented by flexural rigidity instead of the elastic modulus. The geometrical moment of inertia of the strength adjustment layer 200 is calculated based on a cross section obtained by cutting the strength adjustment layer 200 along a plane perpendicular to the direction in which the wiring 190 extends. The bending rigidity of the strength adjustment layer 200 may be 1.1 times or more, more preferably 2 times or more, and still more preferably 10 times or more that of the base material 20 .

A method for forming the strength adjustment layer 200 is appropriately selected according to the material and the like. For example, a method of forming the wiring 190 on the base material 20 or on a supporting base material 410 to be described later and then printing the material constituting the strength adjustment layer 200 on the wiring 190 by a printing method can be used.
Further, when the strength adjustment layer 200 is formed by the printing method, the thickness of the strength adjustment layer thin portion 201 can be set to T11, and the thickness of the other portion of the strength adjustment layer 200 can be set to T10.

<Ninth Embodiment>
Next, a ninth embodiment of the present disclosure will be described.
A wiring board according to a ninth embodiment of the present disclosure includes a first surface and a second surface located on the opposite side of the first surface, a stretchable base material, and the first surface of the base material. and a plurality of wirings located on the side, the plurality of wirings including a first wiring and a second wiring, and when viewed along the normal direction of the first surface of the base material, The first wiring has a first strength adjustment layer that overlaps with the first wiring, the second wiring has a second strength adjustment layer that overlaps with the second wiring, and the second wiring has a second strength adjustment layer that overlaps with the second wiring. One strength adjustment layer has a first strength adjustment layer thin portion in which the thickness of the first strength adjustment layer is partially smaller, and the second strength adjustment layer has a thin portion in the second strength adjustment layer. The wiring board has a second strength adjustment layer thin portion having a partially small thickness, wherein the thickness of the first strength adjustment layer thin portion is smaller than the thickness of the second strength adjustment layer thin portion.

FIG. 11 is a diagram showing an example of a wiring board according to the ninth embodiment of the present disclosure, (a) is a plan view, (b) is a cross-sectional view taken along the line HH of (a), and (c) is a It is a cross-sectional view taken along the line II of (a). In the ninth embodiment of the present disclosure, the number of wirings and strength adjustment layers and the cross-sectional shape of the strength adjustment layer thin portion of each strength adjustment layer in the eighth embodiment of the present disclosure (see FIG. 9) described above are are different and other components may be the same.

For example, a wiring board 210 shown in FIG. 11 includes a base material 20 having elasticity and a plurality of wirings (first wirings 220 and second wirings 240) located on the first surface 21 side of the base material 20. ing.
When viewed along the normal direction of the first surface 21 of the base material 20, the first wiring 220 has a first strength adjustment layer 230 overlapping the first wiring 220, and the second The wiring 240 has a second strength adjustment layer 250 overlapping the second wiring 240 .
The first strength adjustment layer 230 has first strength adjustment layer thin portions 231 where the thickness of the first strength adjustment layer 230 is partially reduced. That is, as shown in FIG. 11B, the thickness (T13) of the first strength adjustment layer thin portion 231 is smaller than the thickness (T12) of the other portion of the first strength adjustment layer 230. As shown in FIG.
The second strength adjustment layer 250 also has a second strength adjustment layer thin portion 251 where the thickness of the second strength adjustment layer 250 is partially reduced. That is, as shown in FIG. 11C, the thickness (T14) of the second strength adjustment layer thin portion 251 is smaller than the thickness (T12) of the other portion of the second strength adjustment layer 250. As shown in FIG.
The thickness (T13) of the first strength adjustment layer thin portion 231 is smaller than the thickness (T14) of the second strength adjustment layer thin portion 251. As shown in FIG.

Since the wiring board 210 has the above-described structure, as the base material 20 expands and contracts, wiring deterioration first occurs in the portion of the first wiring 220 that overlaps the thin portion 231 of the first strength adjustment layer, and then deterioration occurs. In addition, wiring deterioration occurs in the portion of the second wiring 240 that overlaps with the thin portion 251 of the second strength adjustment layer. That is, it is possible to cause wiring deterioration in stages. Therefore, the user can know the deterioration of the wiring of the electronic device including the wiring board 210 in stages.
For example, in an electronic device including the wiring board 210, it is possible to issue a first warning due to wiring deterioration of the first wiring 220 and to issue a second warning due to wiring deterioration of the second wiring 240. can.

Although FIG. 11 illustrates the wiring board 210 having two wirings, the first wiring 220 and the second wiring 240, the ninth embodiment of the present disclosure is not limited to this.
For example, the wiring board may have three or more wires, and the strength adjustment layer thin portion of the strength adjustment layer overlapping each wire may have a different thickness for each wire.
With such a configuration, the wiring deteriorates in order from the wiring having the thin portion of the strength adjustment layer with the smaller thickness. can know

Note that FIG. 11 shows an example in which a strength adjustment layer that overlaps with a plurality of wirings is formed above each wiring (the Z direction side in the drawing), but the ninth embodiment of the present disclosure includes: It is not limited to this. As in the embodiment illustrated in FIG. 10, the strength adjustment layer overlapping the plurality of wirings may be formed below each wiring.
For example, the first strength adjustment layer 230 may be formed between the first surface 21 of the base material 20 and the first wiring 220, and similarly, the second strength adjustment layer 250 may be formed between the base material 20 may be formed between the first surface 21 of and the second wiring 240 .

Also in the present embodiment, as in the above-described first embodiment of the present disclosure, the form of the wiring may be a horseshoe-shaped wiring or a bellows-shaped wiring.

<Tenth Embodiment>
Next, a tenth embodiment of the present disclosure will be described.
A wiring board according to a tenth embodiment of the present disclosure includes a first surface and a second surface located opposite to the first surface, a stretchable base material, and the first surface of the base material. and one wiring located on the side, and the thickness of the base material overlapping the one wiring is partially different when viewed along the normal direction of the first surface of the base material. A wiring board.

12A and 12B are diagrams showing an example of a wiring board according to the tenth embodiment of the present disclosure, where (a) is a plan view and (b) is a cross-sectional view taken along line JJ of (a).

For example, a wiring board 260 shown in FIG. 12 includes an elastic base material 270 and one wiring 280 located on the first surface 271 side of the base material 270 . When viewed along the normal direction of the first surface 271 of the base material 270, the thickness of the base material 270 overlapping the wiring 280 is partially different.
More specifically, as shown in FIG. 12B, the base material 270 has a thin base material part 273 at a position overlapping the wiring 280, and the thickness (T22) of the thin base material part 273 is , is smaller than the thickness (T21) of other portions of the base material 270. As shown in FIG.
That is, the base material thin portion 273 (more specifically, the boundary portion where the thickness of the base material 270 changes from T21 to T22) is mechanically resistant to expansion and contraction of the base material 270 compared to the other portions of the base material 270. It becomes a part with weak physical strength.
Therefore, even in the wiring 280, the portion of the wiring 280 that overlaps with the base material thin portion 273 having a thickness of T22 is larger than the other portion of the wiring 280 (that is, the portion of the wiring 280 that overlaps with the base material 270 having a thickness of T21). Therefore, the base material 270 has a weak mechanical strength against expansion and contraction.

Due to the structure described above, in the wiring board 260, as the base material 270 expands and contracts, the wiring deterioration occurs first in the portion of the wiring 280 that overlaps the base thin part 273 having the thickness T22. Deterioration of the wiring 280 causes disconnection or an increase in resistance value in a circuit related to the wiring 280, and the deterioration of the wiring can be notified to the user.

The material of the wiring 280 can be the same material as the wiring 30 in the above-described first embodiment of the present disclosure (see FIG. 1). can be formed.

Also in the present embodiment, as in the above-described first embodiment of the present disclosure, the form of the wiring may be a horseshoe-shaped wiring or a bellows-shaped wiring.

In addition, the material of the base material 270 can be the same material as that of the base material 20 in the above-described first embodiment of the present disclosure (see FIG. 1).

Examples of materials that constitute the base material 270 include elastomers. As the material of the base material 270, for example, cloth such as woven fabric, knitted fabric, and non-woven fabric can also be used. As the elastomer, general thermoplastic elastomers and thermosetting elastomers can be used. Specifically, polyurethane-based elastomers, styrene-based elastomers, nitrile-based elastomers, olefin-based elastomers, vinyl chloride-based elastomers, ester-based elastomers, Amide elastomers, 1,2-BR elastomers, fluorine elastomers, silicone rubbers, urethane rubbers, fluorine rubbers, polybutadiene, polyisobutylene, polystyrene butadiene, polychloroprene and the like can be used. Considering mechanical strength and abrasion resistance, it is preferable to use a urethane-based elastomer. Base material 20 may also contain silicone such as polydimethylsiloxane. Silicone is excellent in heat resistance, chemical resistance, and flame resistance, and is preferable as a material for the base material 270 .

For the wiring substrate 260 having the above-described configuration, for example, after the wiring 280 is formed on the first surface side of the elastic base material, the second surface of the base material is attached to the desired portion overlapping the wiring 280 . It can be obtained by applying grinding or the like from the side.
Further, for example, when an elastomer is used as a material for forming the base material 270, the base material 270 is shaped with a mold or the like, and the base material 270 having a partially different thickness at a desired position is manufactured in advance. The wiring board 260 can also be obtained by forming the wiring 280 in alignment with the material 270 .

<Eleventh Embodiment>
Next, an eleventh embodiment of the present disclosure will be described.
A wiring board according to an eleventh embodiment of the present disclosure includes a first surface and a second surface located opposite to the first surface, a stretchable base material, and the first surface of the base material. and a plurality of wirings located on the side, the plurality of wirings including a first wiring and a second wiring, and when viewed along the normal direction of the first surface of the base material, The base material includes a first thin base material portion having a small thickness partially overlapping the first wiring, and a thin base material partially having a small thickness overlapping the second wiring. The wiring board has a second base thin portion, wherein the thickness of the first base thin portion is smaller than the thickness of the second base thin portion.

FIG. 13 is a diagram showing an example of a wiring board according to the eleventh embodiment of the present disclosure, (a) is a plan view, (b) is a cross-sectional view along line KK of (a), and (c) is a It is a cross-sectional view taken along line LL in (a).
The eleventh embodiment of the present disclosure differs from the above-described tenth embodiment of the present disclosure (see FIG. 12) in the number of wirings and thin base material parts and the cross-sectional shape of thin base material parts that overlap each wiring. and the other components may be the same.

For example, a wiring board 290 shown in FIG. 13 includes a base material 300 having elasticity and a plurality of wirings (first wirings 310 and second wirings 320) located on the first surface 301 side of the base material 300. ing. When viewed along the normal direction of the first surface 301 of the base material 300 , the base material 300 has a first thin base material portion 303 overlapping the first wiring 310 and a second wiring 320 . It has a second base material thin portion 304 that overlaps with the base material.
Here, as shown in FIG. 13B, the thickness (T24) of the first base material thin portion 303 is smaller than the thickness (T23) of the other portion of the base material 300. As shown in FIG. In addition, as shown in FIG. 13C, the thickness (T25) of the second base material thin portion 304 is smaller than the thickness (T23) of the other portion of the base material 300. As shown in FIG. The thickness (T24) of the first base thin portion 303 is smaller than the thickness (T25) of the second base thin portion 304. As shown in FIG.

Since the wiring board 290 has the above-described configuration, as the base material 300 expands and contracts, wiring deterioration first occurs in the portion of the first wiring 310 that overlaps the first base thin part 303, and then deterioration occurs. , wiring deterioration occurs in the portion of the second wiring 240 that overlaps with the second substrate thin portion 304 . That is, it is possible to cause wiring deterioration in stages. Therefore, the user can know the deterioration of the wiring of the electronic device including the wiring board 290 in stages.
For example, in an electronic device including the wiring board 290, it is possible to issue a first warning due to wiring deterioration of the first wiring 310 and to issue a second warning due to wiring deterioration of the second wiring 320. can.

Note that the example shown in FIG. 13 illustrates the wiring substrate 290 having two wirings, but the eleventh embodiment of the present disclosure is not limited to this.
For example, the wiring board may have three or more wirings, and the thickness of the base material thin portion overlapping each wiring may be different for each wiring.
With such a configuration, the wiring deteriorates in order from the wiring having the thinner portion of the base material with the smaller thickness, so that the user can know the deterioration of the wiring of the electronic device provided with this wiring substrate more finely and step by step. can do

Also in the present embodiment, as in the above-described first embodiment of the present disclosure, the form of the wiring may be a horseshoe-shaped wiring or a bellows-shaped wiring.

<Twelfth Embodiment>
Next, a twelfth embodiment of the present disclosure will be described.
A wiring board according to a twelfth embodiment of the present disclosure includes a first surface and a second surface located on the opposite side of the first surface, a stretchable base material, and the first surface of the base material. and an expansion/contraction adjustment portion that overlaps with the one wiring when viewed along the normal direction of the first surface of the base material, wherein the one wiring is the The one wiring has a bellows shape in which peaks and valleys in the normal direction of the first surface of the base material repeatedly appear along the in-plane direction of the first surface of the base material, and the expansion and contraction adjustment is performed in the one wiring. In the wiring board, the period of the bellows shape in the portion overlapping with the portion is different from the period of the bellows shape in the portion not overlapping with the expansion/contraction adjusting portion.

14A and 14B are diagrams showing an example of a wiring board according to the twelfth embodiment of the present disclosure, where (a) is a plan view and (b) is a cross-sectional view taken along line MM of (a).
A wiring board 330 shown in FIG. 14 includes at least a base material 340 , wiring 350 and an expansion/contraction adjusting portion 360 . Each component of the wiring board 330 will be described below.

[Base material]
The base material 340 is a member configured to have elasticity, and includes a first surface 341 located on the wiring 350 side and a second surface 342 located on the opposite side of the first surface 341 . As the base material 340, the same material as the base material 20 in the above-described first embodiment of the present disclosure (see FIG. 1) can be used.

[wiring]
The wiring 350 is a member having conductivity and having an elongated shape in plan view. The wiring 350 is located on the first surface 341 side of the base material 340 , and the peaks 351 and the valleys 352 in the normal direction of the first surface 341 of the base material 340 are the surfaces of the first surface 341 of the base material 340 . It has a bellows shape that repeatedly appears along the inward direction.
As will be described later, the wiring 350 is provided on the base material 340 in a state of being stretched by tensile stress. In this case, when the tensile stress is removed from the base material 340 and the base material 340 contracts, the wiring 350 deforms into a bellows shape as shown in FIG.

As the material of the wiring 350, the same material as that of the wiring 30 in the above-described first embodiment of the present disclosure (see FIG. 1) can be used.

For example, non-stretchable materials include metals such as gold, silver, copper, aluminum, platinum, and chromium, and alloys containing these metals.
Further, examples of stretchable materials include conductive compositions containing conductive particles and an elastomer.
The conductive particles may be those that can be used for wiring, and examples thereof include particles of gold, silver, copper, nickel, palladium, platinum, carbon, and the like. Among them, silver particles are preferably used.
As the elastomer, general thermoplastic elastomers and thermosetting elastomers can be used. , polybutadiene, polychloroprene, and the like can be used. Among them, resins and rubbers containing urethane-based or silicone-based structures are preferably used in terms of stretchability and durability.

The thickness of the wiring 350 may be any thickness that can withstand expansion and contraction of the base material 340, and is appropriately selected according to the material of the wiring 350 and the like.
For example, when the material of the wiring 350 does not have stretchability, the thickness of the wiring 350 can be in the range of 25 nm or more and 100 μm or less, preferably 50 nm or more and 50 μm or less, and 100 nm or more and 5 μm. It is more preferable to be within the following range.
In addition, when the material of the wiring 350 has elasticity, the thickness of the wiring 350 can be in the range of 5 μm or more and 60 μm or less, preferably in the range of 10 μm or more and 50 μm or less, and 20 μm or more and 40 μm or less. It is more preferable to be within the range.

The width of the wiring 350 is appropriately selected according to the resistance value required for the wiring 350 . The wiring 350 is, for example, 1 μm or more, preferably 50 μm or more. Also, the wiring 350 is, for example, 10 mm or less, preferably 1 mm or less.

A method for forming the wiring 350 is appropriately selected according to the material and the like. For example, a method of forming a metal film on the base material 340 or a support base material 410 to be described later by a vapor deposition method, a sputtering method, or the like and then patterning the metal film by a photolithography method can be used. Further, when the material of the wiring 350 itself has stretchability, for example, the conductive composition containing the above-described conductive particles and elastomer is patterned on the base material 340 or the supporting base material 410 by a general printing method. a method of printing to Among these methods, the printing method, which has high material efficiency and can be manufactured at low cost, can be preferably used.

Advantages of the wiring 350 being formed in a bellows shape will be described. As mentioned above, the base material 340 has an elastic modulus of 10 MPa or less. Therefore, when a tensile stress is applied to the wiring board 330, the base material 340 can be elongated by elastic deformation. Here, if the wiring 350 is similarly elongated by elastic deformation, the total length of the wiring 350 increases and the cross-sectional area of the wiring 350 decreases, so that the resistance value of the wiring 350 increases. Moreover, it is conceivable that damage such as cracks may occur in the wiring 350 due to elastic deformation of the wiring 350 .

In contrast, in the present embodiment, wiring 350 has a bellows shape. Therefore, when the base material 340 is stretched, the wiring 350 can follow the expansion of the base material 340 by deforming to reduce the undulations of the accordion shape, that is, by eliminating the accordion shape. Therefore, it is possible to suppress an increase in the total length of the wiring 350 and a decrease in the cross-sectional area of the wiring 350 due to the extension of the base material 340 . As a result, it is possible to suppress an increase in the resistance value of the wiring 350 due to the extension of the wiring board 330 . Moreover, it is possible to suppress the occurrence of damage such as cracks in the wiring 350 .

As described above, the wiring having the bellows shape prevents deterioration of the wiring by deforming so as to reduce the undulations of the bellows shape with respect to the elongation of the substrate on which the wiring is provided. Therefore, the more the undulations of the bellows shape, that is, the smaller the period of the bellows shape, the more the wiring deterioration can be prevented. Conversely, the smaller the undulations of the bellows shape, that is, the greater the period of the bellows shape, the more likely wiring deterioration occurs.
In the present embodiment, the period of the bellows shape refers to the interval between peaks that appear repeatedly (or the interval between troughs that appear repeatedly) in the bellows shape.

As shown in FIG. 14 , in the wiring board 330 , the wiring 350 has an expansion/contraction adjusting portion 360 that overlaps the wiring 350 when viewed along the normal direction of the first surface 341 of the base material 340 . In the portion of the wiring 350 that overlaps with the adjusting portion 360, the period of the bellows shape is partially different.

More specifically, as shown in FIG. 14B, the wiring board 330 has the wiring 350 on the first surface 341 side of the base material 340, and the wiring 350 on the upper side of the wiring 350 (the Z direction side in the drawing). , and an expansion adjustment unit 360 . The period (F2) of the wiring 350 in the portion overlapping with the expansion/contraction adjusting section 360 is larger than the period (F1) of the wiring 350 in the other portion (that is, the portion not overlapping with the expansion/contraction adjusting section 360).
Therefore, the portion of the wiring 350 that overlaps with the expansion/contraction adjusting portion 360 is weaker in mechanical strength against the expansion/contraction of the base material 340 than the other portions.

Due to the above configuration, in the wiring board 330 , as the base material 340 expands and contracts, the portion of the wiring 350 that overlaps with the expansion/contraction adjusting portion 360 is first deteriorated. Deterioration of the wiring 350 causes disconnection or an increase in resistance value in a circuit related to the wiring 350, and the deterioration of the wiring can be notified to the user.

The periods F1 and F2 of the wiring 350 are, for example, the distance between adjacent peaks (or the distance between adjacent valleys) over a certain range (for example, 10 mm) in the length direction of the wiring 350. distance between the points) and find their average. As a measuring device for measuring the distance between adjacent peaks, a non-contact measuring device using a laser microscope or the like may be used, or a contact measuring device may be used. Alternatively, the distance between adjacent peaks may be measured based on an image such as a cross-sectional photograph.

[Expansion adjustment part]
As described above, the wiring 350 deforms the bellows-shaped undulations to follow the expansion and contraction of the base material 340 . The expansion/contraction adjusting portion 360 is provided for the purpose of partially adjusting the deformation of the wiring 350 . In other words, the expansion/contraction adjuster 360 is provided so that the period of the bellows shape of the wiring 350 is partially different.

The expansion/contraction adjusting portion 360 is positioned so as to overlap at least the wiring 350 in plan view.
In the wiring substrate 330 shown in FIG. 14 , the expansion/contraction adjusting portion 360 is laminated on the first surface 341 side of the base material 340 above the wiring 350 (the Z direction side in the drawing). The expansion/contraction adjusting portion 360 may be in contact with the wiring 350 , or another layer such as an insulating layer may be interposed between the wiring 350 and the expansion/contraction adjusting portion 360 .
Note that “overlapping” means that two components overlap when viewed along the normal direction of the first surface 341 of the base material 340 .
The width of the expansion/contraction adjusting portion 360 (the length in the Y direction shown in FIG. 14A) may be the same as the width of the wiring 350 or may be larger than the width of the wiring 350 .

Note that the expansion/contraction adjusting portion 360 may be formed below the wiring 350 . Although not shown, for example, an expansion adjustment portion 360 may be formed between the first surface 341 of the base material 340 and the wiring 350 . Alternatively, it may be formed inside the base material 340 or on the second surface 342 side of the base material 340 .

The expansion/contraction adjusting portion 360 preferably has an elastic modulus greater than that of the base material 340 . The elastic modulus of the expansion/contraction adjusting portion 360 is, for example, 10 GPa or more and 500 GPa or less, more preferably 1 GPa or more and 300 GPa or less.
If the elastic modulus of the expansion/contraction adjusting portion 360 is too low, there will be no difference in the period of the bellows shape between the portion overlapping the expansion/contraction adjusting portion 360 and the other portion of the wiring 350 . In some cases, it may not be possible to achieve the effect that the portion overlapping with the base material 340 becomes a portion having weaker mechanical strength against the expansion and contraction of the base material 340 than the other portions.
In addition, if the elastic modulus of the expansion/contraction adjusting portion 360 is too high, when the base material 340 expands and contracts, in the wiring 350 , at the boundary between the portion overlapping the expansion/contraction adjusting portion 360 and the other portion, the wiring and the base material may be stretched. Destruction may become excessively likely to occur.
The elastic modulus of the expansion/contraction adjustment part 360 may be 1.1 times or more and 5000 times or less, more preferably 10 times or more and 3000 times or less, that of the base material 340 .

A method for calculating the elastic modulus of the expansion/contraction adjusting section 360 is appropriately determined according to the form of the expansion/contraction adjusting section 360 . For example, the method for calculating the elastic modulus of the expansion/contraction adjusting section 360 may be the same as or different from the method for calculating the elastic modulus of the base material 20 in the above-described first embodiment of the present disclosure. For example, as a method of calculating the elastic modulus of the expansion/contraction adjusting portion 360, a method of performing a tensile test in accordance with ASTM D882 using a sample of the expansion/contraction adjusting portion 360 can be adopted.

When the elastic modulus of the expansion/contraction adjusting portion 360 is larger than the elastic modulus of the base material 340 , a metallic material can be used as the material forming the expansion/contraction adjusting portion 360 . Examples of metal materials include copper, aluminum, stainless steel, and the like. In addition, as a material constituting the expansion/contraction adjusting portion 360, a general thermoplastic elastomer, an acrylic, urethane, epoxy, polyester, epoxy, vinyl ether, polyene/thiol, or silicone oligomer or polymer may be used. etc. may be used. When the materials forming the expansion/contraction adjusting portion 360 are these resins, the expansion/contraction adjusting portion 360 may have transparency. Further, the expansion/contraction adjusting portion 360 may have a light shielding property, for example, a property of shielding ultraviolet rays. For example, the stretch adjustment portion 360 may be black. Moreover, the color of the expansion/contraction adjusting portion 360 and the color of the base material 340 may be the same. The thickness of the expansion/contraction adjusting portion 360 is, for example, 1 μm or more and 3 mm or less, and more preferably 10 μm or more and 500 μm or less.

The characteristics of the expansion/contraction adjusting portion 360 may be represented by bending stiffness instead of the elastic modulus. The geometrical moment of inertia of the expansion/contraction adjusting portion 360 is calculated based on the cross section of the expansion/contraction adjusting portion 360 cut along a plane orthogonal to the direction in which the wiring 350 extends. The flexural rigidity of the expansion/contraction adjustment portion 360 may be 1.1 times or more, more preferably 2 times or more, and still more preferably 10 times or more that of the base material 340 .

A method for forming the expansion/contraction adjusting portion 360 is appropriately selected according to the material and the like. For example, there is a method of forming the wiring 350 on the base material 340 or on a supporting base material 410 described later, and then printing the material forming the expansion/contraction adjusting section 360 on the wiring 350 by a printing method.

In FIG. 14, one wiring 350 included in the wiring board 330 shows a mode in which the period of the bellows shape is partially different, but the present embodiment is not limited to this. A plurality of wirings having partially different shape periods may be provided.
For example, the wiring board 330 includes first wiring and second wiring located on the first surface 341 side of the base material 340, and when viewed along the normal direction of the first surface 341 of the base material 340, , the first wiring has a first wiring expansion/contraction adjusting portion that overlaps with the first wiring, the second wiring has a second wiring expansion/contraction adjusting portion that overlaps with the second wiring, and the first wiring and the second wiring The wiring has a bellows shape in which peaks and valleys in the normal direction of the first surface 341 of the base material 340 repeatedly appear along the in-plane direction of the first surface 341 of the base material 340, and the first wiring In the second wiring, the period of the bellows shape in the portion overlapping with the first wiring expansion/contraction adjusting portion is larger than the period of the bellows shape in the portion not overlapping with the first wiring expansion/contraction adjusting portion, and The period of the bellows shape of the overlapping portion is larger than the period of the bellows shape of the portion that does not overlap with the second wiring expansion/contraction adjusting portion, and the period of the bellows shape of the first wiring in the portion overlapping with the first wiring expansion/contraction adjusting portion is greater than the second wiring expansion/contraction adjusting portion. It is also possible to adopt a mode that is larger than the period of the bellows shape of the second wiring in the portion that overlaps with the two-wiring expansion/contraction adjusting portion.

With such a configuration, wiring deterioration occurs in order from the bellows-shaped wiring having a larger period, so that the user can know the wiring deterioration of the electronic device provided with this wiring substrate in more detail and step by step. .

In order to make the period of the bellows shape of the first wiring in the portion overlapping with the first wiring expansion/contraction adjusting portion larger than the period of the bellows shape of the second wiring in the portion overlapping with the second wiring expansion/contraction adjusting portion, for example, , the elastic modulus of the first wiring expansion/contraction adjusting portion is made larger than the elastic modulus of the second wiring expansion/contraction adjusting portion. In addition, there is a method in which the first wiring expansion/contraction adjusting portion and the second wiring expansion/contraction adjusting portion are made of the same material, and the thickness of the first wiring expansion/contraction adjusting portion is made thicker than the thickness of the second wiring expansion/contraction adjusting portion.

(Method for manufacturing wiring board)
A method of manufacturing the wiring board 330 will be described below with reference to FIGS.

First, as shown in FIG. 15( a ), a substrate preparation step is performed to prepare a stretchable substrate 340 . Subsequently, as shown in FIG. 15(b), a substrate elongation step of applying a tensile stress T to the substrate 340 to elongate the substrate 340 is performed. Subsequently, as shown in FIG. 15(c), a wiring forming step of providing wiring 350 on the first surface 341 of the base material 340 stretched by the tensile stress T is performed. In addition, an expansion/contraction adjusting portion forming step of providing an expansion/contraction adjusting portion 360 on the first surface 341 side of the base material 340 in a state of being elongated by the tensile stress T is performed.

After that, a substrate contraction step is performed to remove the tensile stress T from the substrate 340 . As a result, as indicated by arrow C in FIG. 15D, the base material 340 contracts, and the wiring 350 provided on the base material 340 also deforms into a bellows shape.

Here, in the wiring 350, the deformation of the wiring 350 is different between the portion that overlaps the expansion/contraction adjustment portion 360 and the other portion (the portion that does not overlap the expansion/contraction adjustment portion 360).

For example, as shown in FIG. 15(c), the wiring 350 provided on the base material 340 stretched to the length L1 by the tensile stress T, in this state (state where the base material 340 is stretched), has a length of L2, but as shown in FIG. 15(d), the wiring 350 of the base material 340 in a state where the tensile stress T is removed and the length L4 is shrunk is in this state (state where the base material 340 is shrunk). Then the length becomes L5.

On the other hand, as shown in FIG. 15(c), the expansion/contraction adjusting portion 360 provided on the base material 340 in a state of being stretched to the length L1 by the tensile stress T is Although the length is L3, as shown in FIG. 15(d), the expansion/contraction adjusting portion 360 of the base material 340 in a state where the tensile stress T is removed and the length is L4 is reduced to this state (the base material 340 In the contracted state), it has a length L6.

Here, since the expansion/contraction adjusting portion 360 is present, when the base material 340 contracts, the wiring 350 is expanded between the portion overlapping the expansion/contraction adjusting portion 360 and the other portion (the portion not overlapping the expansion/contraction adjusting portion 360) in the wiring 350. There is also a difference in the contraction of

For example, when the expansion/contraction adjusting portion 360 has a larger elastic modulus than the base material 340, the degree of contraction (L6/L3) of the portion overlapping the expansion/contraction adjusting portion 360 does not overlap with the expansion/contraction adjusting portion 360. The degree of contraction of the part is smaller than ((L5-L6)/(L2-L3)).
That is, in the wiring board 330 in the state shown in FIG. 15(d), the period (F2) of the wiring 350 in the portion overlapping with the expansion/contraction adjusting portion 360 is different from that in the other portion (that is, the portion not overlapping with the expansion/contraction adjusting portion 360). It becomes larger than the period (F1) of the wiring 350 .
Therefore, the portion of the wiring 350 that overlaps with the expansion/contraction adjusting portion 360 is weaker in mechanical strength against the expansion/contraction of the base material 340 than the other portions.

<Thirteenth Embodiment>
Next, a thirteenth embodiment of the present disclosure will be described.
In the twelfth embodiment of the present disclosure described above, an example in which the wiring 350 is provided on the first surface 341 of the base material 340 is shown, but in this embodiment, the wiring 350 is supported by the supporting base material 410 example.

16A and 16B are diagrams showing an example of a wiring board according to the thirteenth embodiment of the present disclosure, where (a) is a plan view and (b) is a cross-sectional view taken along line NN of (a).
A wiring board 400 shown in FIG. 16 includes at least a base material 340 , a support base material 410 , wiring 350 and an expansion/contraction adjusting portion 360 . Each component of the wiring board 400 will be described below.
In addition, since the same materials as those of the twelfth embodiment of the present disclosure described above can be used for the base material 340, the wiring 350, and the expansion/contraction adjusting portion 360, the description thereof will be omitted here.

[Support base material]
The support base material 410 is a plate-like member configured to have lower stretchability than the base material 340 . The supporting substrate 410 includes a second surface 412 located on the side of the substrate 340 and a first surface 411 located on the opposite side of the second surface 412 . In the example shown in FIG. 16, the support base material 410 supports the wiring 350 on the first surface 411 side. Further, the support base material 410 is joined to the first surface 341 side of the base material 340 on the second surface 412 side thereof.
For example, an adhesive layer 420 containing an adhesive may be provided between the substrate 340 and the supporting substrate 410 . As a material forming the adhesive layer 420, for example, an acrylic adhesive, a silicone adhesive, or the like can be used. The thickness of the adhesive layer 420 is, for example, 5 μm or more and 200 μm or less. Also, although not shown, the second surface 412 of the support substrate 410 may be joined to the first surface 341 of the substrate 340 by a method of molecularly modifying the non-adhesive surface for molecular adhesive bonding. In this case, an adhesive layer may not be provided between the base material 340 and the supporting base material 410 .

In this embodiment, as shown in FIG. 16, the support base 410 and the wiring 350 are formed in a bellows shape. The properties and dimensions of the support base 410 are set to facilitate formation of such a bellows shape. For example, support substrate 410 has an elastic modulus greater than that of substrate 340 .

The elastic modulus of the support base material 410 is, for example, 100 MPa or more, and more preferably 1 GPa or more. The elastic modulus of the supporting base material 410 may be 100 times or more and 50000 times or less, preferably 1000 times or more and 10000 times or less, that of the base material 340 . By setting the elastic modulus of the supporting base material 410 in this manner, it is possible to prevent the period of the bellows shape from becoming too small. Moreover, it is possible to suppress the occurrence of local bending in the bellows shape.
If the modulus of elasticity of the support base material 410 is too low, the support base material 410 is likely to deform during the process of forming the expansion/contraction adjusting portion 360 , making it difficult to align the expansion/contraction adjusting portion 360 with respect to the wiring 350 , for example. Further, if the elastic modulus of the supporting base material 410 is too high, it becomes difficult to restore the base material 340 when relaxed, and the base material 340 is likely to crack or break.

Further, the thickness of the support base material 410 is, for example, 500 nm or more and 10 μm or less, more preferably 1 μm or more and 5 μm or less. If the thickness of the supporting base material 410 is too small, it becomes difficult to handle the supporting base material 410 in the process of manufacturing the supporting base material 410 and the process of forming members on the supporting base material 410 . If the thickness of the supporting base material 410 is too large, it becomes difficult to restore the base material 340 when relaxed, and the target expansion and contraction of the base material 340 cannot be obtained.

As a material for forming the supporting base material 410, for example, polyethylene naphthalate, polyimide, polyethylene terephthalate, polycarbonate, acrylic resin, or the like can be used. Among them, polyethylene naphthalate or polyimide having good durability and heat resistance can be preferably used.

The modulus of elasticity of the support substrate 410 may be 100 times or less than the modulus of elasticity of the substrate 340 . The method of calculating the elastic modulus of the support base material 410 is the same as in the case of the base material 20 in the above-described first embodiment of the present disclosure (see FIG. 1).

(Method for manufacturing wiring board)
A method of manufacturing the wiring board 400 will be described below with reference to FIGS.

First, as shown in FIG. 17A, a supporting base 410 is prepared, and wiring 350 is provided on the first surface 411 side of the supporting base 410 . Further, an expansion adjustment part 360 is provided on the first surface 411 side of the support base material 410 .

Subsequently, as shown in FIG. 17B, a first step is performed in which a tensile stress T is applied to a separately prepared base material 340 to elongate the base material 340 . The elongation rate of the base material 340 is, for example, 10% or more and 200% or less. The first step may be performed while the substrate 340 is heated, or may be performed at room temperature. When heating the base material 340, the temperature of the base material 340 is, for example, 50° C. or higher and 100° C. or lower.

Subsequently, a second step of providing the wiring 350 on the first surface 341 side of the base material 340 stretched by the tensile stress T is performed. In the second step of the present embodiment, as shown in FIG. The material 410 is joined from the second surface 412 side. At this time, an adhesive layer 420 may be provided between the substrate 340 and the supporting substrate 410 .

After that, the third step of removing the tensile stress T from the base material 340 is performed. As a result, the base material 340 shrinks as indicated by arrow C in FIG. The modulus of elasticity of support substrate 410 is greater than that of substrate 340 . Therefore, the deformation of the supporting substrate 410 and the wiring 350 can be caused as the generation of a bellows shape.

In the wiring board 400 of the present embodiment, as in the wiring board 330 of the twelfth embodiment of the present disclosure, in the wiring 350, the portion overlapping the expansion/contraction adjustment portion 360 and the other portion (the expansion/contraction adjustment portion 360), the deformation of the wiring 350 is different.

For example, as shown in FIG. 17(c), the wiring 350 provided on the support base material 410 joined to the base material 340 in a state of being stretched to the length L11 by the tensile stress T is in this state (the base material 340 17(d), the wiring 350 on the base material 340 contracted to a length L14 after the tensile stress T is removed has a length L12 in this state ( When the base material 340 is shrunk, the length becomes L15.

On the other hand, as shown in FIG. 17(c), the expansion/contraction adjusting portion 360 provided on the support base material 410 joined to the base material 340 in a state of being stretched to the length L11 by the tensile stress T is in this state (base state). The length L13 in the state where the material 340 is stretched), but as shown in FIG. , in this state (the state in which the base material 340 is contracted), the length is L16.

Here, since the expansion/contraction adjusting portion 360 is present, when the base material 340 contracts, the wiring 350 is expanded between the portion overlapping the expansion/contraction adjusting portion 360 and the other portion (the portion not overlapping the expansion/contraction adjusting portion 360) in the wiring 350. There is also a difference in the contraction of

For example, when the expansion/contraction adjusting portion 360 has a larger elastic modulus than the base material 340, the degree of contraction (L16/L13) of the portion overlapping the expansion/contraction adjusting portion 360 does not overlap with the expansion/contraction adjusting portion 360. The degree of contraction of the portion is smaller than ((L15-L16)/(L12-L13)).
That is, in the wiring board 400 in the state shown in FIG. 17D, the period (F2) of the wiring 350 in the portion overlapping with the expansion/contraction adjusting portion 360 is the same as that in the other portion (that is, the portion not overlapping with the expansion/contraction adjusting portion 360). It becomes larger than the period (F1) of the wiring 350 .
Therefore, the portion of the wiring 350 that overlaps with the expansion/contraction adjusting portion 360 is weaker in mechanical strength against the expansion/contraction of the base material 340 than the other portions.

In the wiring board 400 illustrated in FIG. 16, an example is shown in which the expansion/contraction adjusting portion 360 is positioned above the wiring 350 (the Z direction side in the drawing), but the present embodiment is not limited to this. do not have.
For example, as shown in FIG. 18( a ), the expansion/contraction adjuster 360 may be positioned between the wiring 350 and the supporting base material 410 . Moreover, although not shown, the expansion/contraction adjusting portion 360 may be positioned between the support base material 410 and the adhesive layer 420 .
Moreover, as shown in FIG. 18(b), the expansion/contraction adjusting portion 360 may be positioned between the adhesive layer 420 and the base material 340. As shown in FIG. Moreover, although not shown, the expansion/contraction adjusting portion 360 may be positioned on the second surface 342 side of the base material 340 .
Moreover, as shown in FIG. 18C, the expansion/contraction adjusting portion 360 may be embedded inside the base material 340 .

10 Wiring board 20 Base material 21 First surface 22 Second surface 30 Wiring 31 Narrow portion 40 Wiring substrate 50 First wiring 51 First narrow wiring portion 60 Second wiring 61 Second narrow wiring portion 70 Wiring 71 First direction Portion 72 Curved portion 73 Second direction portion 80 First wire 81 First direction portion 82 First wire curved portion 83 Second direction portion 90 Second wire 91 Third direction portion 92 Second wire curved portion 93 Fourth direction Part 110 Wiring board 120 Wiring 121 First material part 122 Second material part 130 Wiring board 140 Wiring 141 Thin wiring part 150 Wiring board 160 First wiring 161 First thin wiring part 170 Second wiring 171 Second wiring Thin portions 180, 181 Wiring board 190 Wiring 200 Strength adjustment layer 201 Strength adjustment layer thin portion 210 Wiring substrate 220 First wiring 230 First strength adjustment layer 231 First strength adjustment layer thin portion 240 Second wiring 250 Second strength adjustment layer 251 second strength adjustment layer thin portion 260 wiring substrate 270 base material 271 first surface 272 second surface 273 base thin portion 280 wiring 290 wiring substrate 300 base material 301 first surface 302 second surface 303 first surface Base material thin part 304 Second base material thin part 310 First wiring 320 Second wiring 330 Wiring board 340 Base material 341 First surface 342 Second surface 350 Wiring 351 Peak 352 Valley 360 Expansion adjustment parts 400 and 401 , 402, 403 Wiring substrate 410 Support base material 411 First surface 412 Second surface 420 Adhesive layer 500 Wiring substrate 411 First surface 412 Second surface

Claims (9)

a stretchable base material including a first surface and a second surface located on the opposite side of the first surface;
a plurality of wirings located on the first surface side of the base material;
with
The plurality of wirings includes a first wiring and a second wiring,
Since the width of the wiring in the first wiring is partially small, the first wiring has a weaker mechanical strength than other portions of the first wiring against expansion and contraction of the base material. It has a wiring narrow part,
Since the width of the wiring in the second wiring is partially small, the second wiring has a weaker mechanical strength than other portions of the second wiring against expansion and contraction of the base material. It has a wiring narrow part,
Since the width of the first wiring narrow portion is smaller than the width of the second wiring narrow portion, the mechanical strength of the first wiring narrow portion against expansion and contraction of the base material is lower than that of the second wiring narrow portion. A wiring board that is weaker than the mechanical strength of a stretchable base material including a first surface and a second surface located on the opposite side of the first surface;
a plurality of wirings located on the first surface side of the base material;
with
The plurality of wirings includes a first wiring and a second wiring,
In the in-plane direction of the first surface of the base material,
The first wiring is
having a first direction portion extending in a first direction, a first wiring bending portion bending from the first direction to a second direction, and a second direction portion extending in the second direction;
Since the width of the wiring in the first wiring bending portion is smaller than the width of the wiring in the first direction portion and the width of the wiring in the second direction portion, the bending of the first wiring with respect to the expansion and contraction of the base material. the mechanical strength of the portion is weaker than the mechanical strength of the first direction portion and the second direction portion ;
The second wiring is
a third direction portion extending in a third direction, a second wiring bending portion bending from the third direction to a fourth direction, and a fourth direction portion extending in the fourth direction;
Since the width of the wiring in the second wiring curved portion is smaller than the width of the wiring in the third direction portion and the width of the wiring in the fourth direction portion, the bending of the second wiring with respect to the expansion and contraction of the base material the mechanical strength of the portion is weaker than the mechanical strength of the third direction portion and the fourth direction portion ;
Since the width of the wiring in the first wiring curved portion is smaller than the width of the wiring in the second wiring curved portion, the mechanical strength of the first wiring curved portion against expansion and contraction of the base material is lower than that of the first wiring curved portion. 2 A wiring board that is weaker than the mechanical strength of the wiring curved portion . 3. The wiring has a bellows shape in which peaks and valleys in the normal direction of the first surface of the base material repeatedly appear along the in-plane direction of the first surface of the base material. Item 3. The wiring board according to item 2 . The amplitude of peaks and troughs appearing in a portion of the second surface of the substrate opposite to the first surface, which overlaps with the bellows shape, is equal to the bellows shape of the first surface of the base material. 4. The wiring board according to claim 3 , wherein the amplitude is smaller than the amplitude of the ridges and troughs appearing in the portion overlapping with . The amplitude of peaks and troughs appearing in a portion of the second surface of the substrate opposite to the first surface, which overlaps with the bellows shape, is equal to the bellows shape of the first surface of the base material. 5. The wiring board according to claim 4 , wherein the amplitude is 0.9 times or less than the amplitude of the ridges and valleys appearing in the portion overlapping with . The period of peaks and troughs appearing in a portion overlapping the bellows shape on the second surface of the base material opposite to the first surface is the bellows shape on the first surface of the base material. 6. The wiring board according to claim 3 , wherein the period of the peaks and valleys appearing in the portion overlapping with . The period of peaks and troughs appearing in a portion overlapping the bellows shape on the second surface of the base material opposite to the first surface is the bellows shape on the first surface of the base material. 7. The wiring board according to claim 6 , which is 1.1 times or more the period of the ridges and troughs appearing in the portion overlapping with . The positions of peaks and valleys appearing in a portion of the second surface opposite to the first surface of the base material, which overlaps with the bellows shape, correspond to the bellows shape of the first surface of the base material. 8. The wiring board according to claim 3 , wherein the positions of the troughs and peaks appearing in the portions overlapping with the . When the period of peaks and troughs appearing in the bellows-shaped portion of the first surface of the base material is F3, the second surface of the base material located on the opposite side of the first surface is The positions of peaks and troughs appearing in the portion overlapping the bellows shape are 0.1×F3 or more from the positions of the troughs and peaks appearing in the portion overlapping the bellows shape of the first surface of the base material. 9. The wiring board of claim 8 , which is offset.

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