Stretchable wiring board

Abstract

A stretchable wiring substrate 1A comprises: a stretchable base material 10A that has a first main surface 10Aa and a second main surface 10Ab opposing each other in a thickness direction T; and a wiring member 20A which is provided at least on the first main surface 10Aa side of the stretchable base material 10A, and is composed of at least one stretchable wire extending in a plane direction which includes a length direction L orthogonal to the thickness direction T, and a width direction W orthogonal to the thickness direction T and to the length direction L. The wiring member 20A includes a first wiring portion 20Aa and a second wiring portion 20Ab that both extend in the length direction L. The first wiring portion 20Aa constitutes an electric path to the outside. In the wiring member 20A, the tensile strength of the second wiring portion 20Ab in the length direction L is lower than the tensile strength of portions other than the second wiring portion 20Ab that include the first wiring portion 20Aa in the length direction L.

Description

[Technical field]

[0001] The present invention relates to a stretchable wiring board. [Background technology]

[0002] Patent Document 1 discloses a cord-like thermal fuse having a linear fuse disposed within an insulating sheathed tube, characterized in that the linear fuse is bent into a shape that is elastic in the longitudinal direction. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 10-188756 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, the condition of the human body has been managed by acquiring and analyzing biological information (vital signs) using a stretchable wiring board. When a stretchable wiring board is used in a state where it is attached to the human body, for example, the wiring used in the stretchable wiring board is required to have stretchability that allows it to follow the movement of the human body. In other words, the wiring used in the stretchable wiring board is required to be a stretchable wiring having stretchability.

[0005] However, even if the wiring used in the elastic wiring board is elastic wiring, if the elastic wiring board is stretched more than expected, the resistance of the elastic wiring board is likely to increase with the stretching of the elastic wiring board. If the resistance of the elastic wiring increases in this way, the elastic wiring may heat up and become easily disconnected when an excessive current flows through the elastic wiring. Furthermore, if the elastic wiring board is used while the resistance of the elastic wiring is still high, there is a risk that errors will occur in the acquired biometric information, or that the elastic wiring may heat up when an excessive current flows through it, causing adverse effects such as burns to the human body.

[0006] In response to this, it is conceivable to incorporate an expandable fuse such as the cord-shaped thermal fuse described in Patent Document 1 into the expandable wiring board, so that when an overcurrent flows through the expandable wiring in a state where the expandable wiring board is stretched more than expected, the fuse will blow, electrically destroying the expandable wiring board. However, it is technically difficult to incorporate the cord-shaped thermal fuse having a hollow structure described in FIG. 1 of Patent Document 1 into the expandable wiring board. Even if it were possible to incorporate the cord-shaped thermal fuse described in Patent Document 1 into the expandable wiring board, the expandable wiring board would reach a high temperature when the cord-shaped thermal fuse blows, which could have an adverse effect on the human body.

[0007] For these reasons, when a stretchable wiring board is used in a state where it is attached to the human body, a mechanism is required that can safely detect an excessively stretched state of the stretchable wiring board.

[0008] The present invention has been made to solve the above problems, and has an object to provide a stretchable wiring board that can safely detect an excessively stretched state. [Means for solving the problem]

[0009] The stretchable wiring board of the present invention comprises a stretchable substrate having a first main surface and a second main surface opposing each other in a thickness direction, and a wiring member provided on at least the first main surface side of the stretchable substrate and composed of at least one stretchable wire extending in a surface direction including a length direction perpendicular to the thickness direction and a width direction perpendicular to the thickness direction and the length direction, the wiring member including a first wiring section and a second wiring section that extend together in the length direction, the first wiring section forming an electrical path to the outside, and the wiring member characterized in that the tensile strength in the length direction of the second wiring section is lower than the tensile strength in the length direction of a portion other than the second wiring section including the first wiring section. Effect of the Invention

[0010] According to the present invention, it is possible to provide a stretchable wiring board capable of safely detecting an excessively stretched state. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic perspective view showing an example of the stretchable wiring board according to the first embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic perspective view showing an example of a stretchable wiring board according to a modified example of the first embodiment of the present invention. [Diagram 3] FIG. 3 is a schematic perspective view showing an example of the stretchable wiring board according to the second embodiment of the present invention. [Figure 4] FIG. 4 is a schematic perspective view showing an example of a stretchable wiring board according to a modified example of the second embodiment of the present invention. [Diagram 5] FIG. 5 is a schematic perspective view showing an example of the stretchable wiring board according to the third embodiment of the present invention. [Figure 6] FIG. 6 is a schematic perspective view showing an example of a stretchable wiring board according to a modified example of the third embodiment of the present invention. [Figure 7] FIG. 7 is a flowchart showing an example of the operation of the stretchable wiring board according to the fourth embodiment of the present invention. [Figure 8] FIG. 8 is a flowchart showing an example of the operation of the stretchable wiring board according to the modified example of the fourth embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The stretchable wiring board of the present invention will be described below. Note that the present invention is not limited to the following configurations, and may be appropriately modified within the scope of the present invention. In addition, a combination of multiple individual preferred configurations described below also constitutes the present invention.

[0013] The following embodiments are merely examples, and it goes without saying that partial replacement or combination of the configurations shown in different embodiments is possible. In the second and subsequent embodiments, the description of the matters common to the first embodiment will be omitted, and the differences will be mainly described. In particular, the same effects and advantages due to the same configuration will not be mentioned one by one for each embodiment.

[0014] The drawings shown below are schematic diagrams, and the dimensions, aspect ratio, and scale may differ from those of the actual product.

[0015] The stretchable wiring board of the present invention comprises a stretchable substrate having a first main surface and a second main surface opposing each other in a thickness direction, and a wiring member provided on at least the first main surface side of the stretchable substrate and composed of at least one stretchable wire extending in a surface direction including a length direction perpendicular to the thickness direction and a width direction perpendicular to the thickness direction and the length direction, the wiring member including a first wiring section and a second wiring section that extend together in the length direction, the first wiring section forming an electrical path to the outside, and the wiring member characterized in that the tensile strength in the length direction of the second wiring section is lower than the tensile strength in the length direction of a portion other than the second wiring section including the first wiring section.

[0016] [Embodiment 1] In the stretchable wiring board of embodiment 1 of the present invention, the first wiring section and the second wiring section are provided on different stretchable wirings.

[0017] FIG. 1 is a schematic perspective view showing an example of the stretchable wiring board according to the first embodiment of the present invention.

[0018] The stretchable wiring board 1A shown in FIG. 1 has a stretchable base material 10A and a wiring member 20A.

[0019] In this specification, the length direction, thickness direction, and width direction are respectively defined as directions L, T, and W as shown in Fig. 1 etc. The length direction L, thickness direction T, and width direction W are mutually orthogonal. Moreover, a direction orthogonal to the thickness direction T and including the length direction L and width direction W is defined as a surface direction.

[0020] In this specification, various dimensions in the length direction, thickness direction, and width direction are shown for the stretchable wiring board in an unstretched state unless otherwise specified. Various dimensions in the length direction, thickness direction, and width direction are measured by viewing the stretchable wiring board in a plan view or cross section with an optical microscope.

[0021] The elastic substrate 10A has a first main surface 10Aa and a second main surface 10Ab that face each other in the thickness direction T.

[0022] The stretchable substrate 10A has a narrow portion 11A whose cross-sectional area when viewed in a cross section perpendicular to the length direction L is the smallest.

[0023] In the example shown in FIG. 1, the dimension of the stretchable substrate 10A in the thickness direction T is constant regardless of the position along the length direction L. That is, in the example shown in FIG. 1, the narrow portion 11A corresponds to the portion of the stretchable substrate 10A whose dimension in the width direction W is the smallest. Note that, when the dimension of the stretchable substrate 10A in the width direction W is constant regardless of the position along the length direction L, the narrow portion 11A corresponds to, for example, the portion of the stretchable substrate 10A whose dimension in the thickness direction T is the smallest. In this way, the narrow portion 11A may be any portion of the stretchable substrate 10A whose cross-sectional area is the smallest when viewed in a cross section perpendicular to the length direction L, and various dimensions thereof are not particularly limited.

[0024] The stretchable substrate 10A preferably contains at least one resin selected from the group consisting of styrene-based resins, olefin-based resins, and silicone-based resins. Examples of styrene-based resins include styrene-butadiene-styrene copolymer resins (SBS).

[0025] The dimension of the stretchable substrate 10A in the thickness direction T is preferably 100 μm or less, and more preferably 50 μm or less. When the dimension of the stretchable substrate 10A in the thickness direction T is within the above range, the stretchable wiring board 1A can easily follow the movement of the human body when used in a state where the stretchable wiring board 1A is attached to the human body.

[0026] The dimension of the stretchable substrate 10A in the thickness direction T is preferably 10 μm or more.

[0027] The breaking elongation rate of the stretchable substrate 10A in the length direction L is preferably 50% or more. When the breaking elongation rate of the stretchable substrate 10A in the length direction L is within the above range, the stretchable wiring board 1A can easily follow the movement of the human body when used in a state where the stretchable wiring board 1A is attached to the human body.

[0028] From the viewpoint of making it easier for the stretchable wiring board 1A to follow the movements of the human body, the higher the breaking elongation rate in the length direction L of the stretchable base material 10A is, within a range of 50% or more, the more preferable it is.

[0029] The Young's modulus of the stretchable substrate 10A is preferably 100 MPa or less, and more preferably 30 MPa or less. When the Young's modulus of the stretchable substrate 10A is within the above range, when the stretchable wiring board 1A is used in a state where it is attached to the human body, the stretchable wiring board 1A is less likely to hinder the stretching of the surface of the human body, and therefore the stretchable wiring board 1A is less likely to cause discomfort.

[0030] The Young's modulus of the stretchable substrate 10A is preferably 3 MPa or more.

[0031] In the example shown in FIG. 1, the shape of the stretchable substrate 10A when viewed in the thickness direction T is such that the dimension in the width direction W is larger at one end than at the other portion.

[0032] The shape of the stretchable substrate 10A when viewed in the thickness direction T may be a shape in which the dimension in the width direction W is constant regardless of the position along the length direction L.

[0033] Furthermore, the shape of the stretchable substrate 10A when viewed from the thickness direction T may be a shape in which one end is looped, for example, a shape in which a straight portion and a loop portion are connected in the length direction L. In this case, the stretchable substrate 10A may have a narrow portion at the position where the straight portion and the loop portion are connected.

[0034] The wiring member 20A is provided on at least the first main surface 10Aa side of the stretchable substrate 10A.

[0035] In the example shown in FIG. 1, the wiring member 20A is provided on the first main surface 10Aa side of the stretchable substrate 10A.

[0036] The wiring member 20A may be provided on the second main surface 10Ab side of the stretchable substrate 10A, in addition to the first main surface 10Aa side of the stretchable substrate 10A.

[0037] In the example shown in Fig. 1, the wiring member 20A is provided on a first main surface 10Aa of the stretchable base material 10A. That is, in the example shown in Fig. 1, the stretchable base material 10A and the wiring member 20A are in contact with each other.

[0038] It should be noted that another member may be interposed between the stretchable base material 10A and the wiring member 20A.

[0039] The wiring member 20A is composed of at least one elastic wire extending in a planar direction including the length direction L and the width direction W.

[0040] In the example shown in FIG. 1, the wiring member 20A is composed of three elastic wires 21Aa, 21Ab, and 21Ac extending in the planar direction.

[0041] The wiring member 20A may be composed of only one elastic wire, may be composed of two elastic wires, or may be composed of four or more elastic wires.

[0042] The dimension of the elastic wiring in the thickness direction T, that is, the dimension of the elastic wiring 21Aa, the elastic wiring 21Ab, and the elastic wiring 21Ac in the thickness direction T in the example shown in Fig. 1 is preferably 100 µm or less, more preferably 50 µm or less. By having the dimension of the elastic wiring in the thickness direction T within the above range, when the elastic wiring board 1A is used in a state where it is attached to the human body, the elastic wiring board 1A can easily follow the movement of the human body.

[0043] The dimension of the elastic wire in the thickness direction T, that is, the dimension of the elastic wire 21Aa, the elastic wire 21Ab, and the elastic wire 21Ac in the example shown in Figure 1 in the thickness direction T is preferably 1 μm or more, more preferably 10 μm or more.

[0044] The elastic wires, the elastic wires 21Aa, 21Ab, and 21Ac in the example shown in FIG. 1, contain, for example, conductive particles and a resin.

[0045] Examples of materials constituting the conductive particles contained in the elastic wiring include metals such as silver, copper, nickel, etc. Among these, silver is preferred from the viewpoint of realizing low resistance of the elastic wiring.

[0046] The average particle size of the conductive particles contained in the elastic wiring is preferably 0.01 μm or more and 10 μm or less.

[0047] The average particle size of the conductive particles contained in the elastic wiring is determined as follows. First, the elastic wiring substrate is polished or the like so that a cross section in which the target elastic wiring is exposed appears. Next, an image of the cross section is taken with a scanning electron microscope (SEM) or the like. Then, the equivalent circle diameter of the conductive particles contained in the elastic wiring is measured by performing image analysis of the taken cross section image, and the obtained equivalent circle diameter is taken as the particle size of the conductive particles. Thereafter, a cumulative particle size distribution based on the number is calculated from the particle size of the conductive particles obtained, and the particle size (median diameter D) at which the cumulative probability in the cumulative particle size distribution based on the number is 50% is determined. 50 ) is defined as the average particle size of the conductive particles.

[0048] The conductive particles contained in the elastic wire are preferably spherical in shape. The conductive particles contained in the elastic wire may be flat, irregularly shaped with protrusions, or the like, in addition to the spherical shape, from the viewpoint of reducing the resistance change of the elastic wire due to stretching.

[0049] When the wiring member 20A is composed of multiple elastic wires, it is preferable that the conductive particles contained in each elastic wire are the same as each other at least in terms of the type of constituent material, but they may be different from each other or may differ in part.

[0050] The resin contained in the elastic wiring is preferably at least one elastomer resin selected from the group consisting of epoxy resins, urethane resins, acrylic resins, and silicone resins. In this case, the elasticity of the elastic wiring is easily ensured. The resin contained in the elastic wiring may be a resin other than the above as long as it can impart the elasticity function.

[0051] When the wiring member 20A is composed of multiple elastic wires, it is preferable that the resin contained in each elastic wire is the same as each other at least in terms of type, but the resins may be different from each other or may be partially different.

[0052] The stretchable wires, the stretchable wires 21Aa, 21Ab, and 21Ac in the example shown in FIG. 1, are formed, for example, as follows. First, a conductive paste containing conductive particles and a resin is applied to at least the first main surface 10Aa of the stretchable substrate 10A. Examples of the method for applying the conductive paste include a screen printing method, an inkjet method, and a dispense method. Then, the applied conductive paste is heat-treated to form the stretchable wires.

[0053] The wiring member 20A includes a first wiring portion 20Aa and a second wiring portion 20Ab, which both extend in the length direction L.

[0054] In this specification, the wiring part (elastic wiring) of the wiring member extends in the length direction means that the wiring part (elastic wiring) has a part that substantially extends in the length direction when the wiring member is viewed as a whole. Note that the wiring part (elastic wiring) of the wiring member may have a part that extends in a direction other than the length direction (for example, the width direction) as long as it has a part that substantially extends in the length direction.

[0055] The first wiring portion 20Aa and the second wiring portion 20Ab are provided on different elastic wires.

[0056] 1, the first wiring portion 20Aa is provided on the elastic wiring 21Aa and the elastic wiring 21Ab, and the second wiring portion 20Ab is provided on the elastic wiring 21Ac. More specifically, the first wiring portion 20Aa corresponds to the entire elastic wiring 21Aa and the elastic wiring 21Ab, and the second wiring portion 20Ab corresponds to the entire elastic wiring 21Ac.

[0057] Each of the first wiring portion 20Aa, the elastic wiring 21Aa and the elastic wiring 21Ab in the example shown in Fig. 1, is electrically connected to the electronic component 30. That is, the first wiring portion 20Aa constitutes an electrical path to the outside, and in the example shown in Fig. 1, an electrical path to the external electronic component 30.

[0058] The electronic component 30 is mounted on each of the first wiring portion 20Aa, and the elastic wire 21Aa and the elastic wire 21Ab in the example shown in FIG. 1, via a bonding member such as solder.

[0059] Examples of the electronic components 30 include diodes, integrated circuits (ICs), capacitors, resistors, inductors, amplifiers (op-amps, transistors, etc.), and the like.

[0060] When, for example, a light-emitting diode, which is a type of diode, is used as the electronic component 30, the first wiring section 20Aa, the stretchable wiring 21Aa and the stretchable wiring 21Ab in the example shown in FIG. 1 function as a drive wiring through which a large current flows to drive the light-emitting diode. In this case, if the stretchable wiring board 1A is excessively stretched in the length direction L, the resistance of the first wiring section 20Aa becomes too high as the first wiring section 20Aa stretches, and it may become difficult for a large current to drive the light-emitting diode to flow to the light-emitting diode through the first wiring section 20Aa, or the first wiring section 20Aa may be easily broken when a large current flows, or the first wiring section 20Aa may be easily heated when a large current flows. In this way, if the stretchable wiring board 1A is excessively stretched in the length direction L, there is a risk that the light-emitting diode as the electronic component 30 will not be lit, or the first wiring section 20Aa may be excessively heated.

[0061] In contrast, in the stretchable wiring board 1A, the wiring member 20A is provided with the second wiring portion 20Ab in addition to the first wiring portion 20Aa, and in the wiring member 20A, the tensile strength in the length direction L of the second wiring portion 20Ab is lower than the tensile strength in the length direction L of the portion other than the second wiring portion 20Ab including the first wiring portion 20Aa. In other words, the tensile strength in the length direction L of the second wiring portion 20Ab is not only lower than the tensile strength in the length direction L of the first wiring portion 20Aa, but is also the lowest among the tensile strengths in the length direction L of the wiring member 20A. As a result, when the stretchable wiring board 1A is stretched in the length direction L, the second wiring portion 20Ab will not only break before the first wiring portion 20Aa, but will also break first in the wiring member 20A.

[0062] Therefore, in the stretchable wiring board 1A, by utilizing the fact that the second wiring portion 20Ab is the first to break when the stretchable wiring board 1A is stretched in the length direction L, it is possible to detect a break in the second wiring portion 20Ab, and thereby detect an excessively stretched state of the stretchable wiring board 1A, such as the stretchable wiring board 1A being excessively stretched in the length direction L, before a defect occurs such as the first wiring portion 20Aa breaking due to the first wiring portion 20Aa being excessively stretched in the length direction L.

[0063] Furthermore, when the stretchable wiring board 1A is used, the user can be prompted to stop using the stretchable wiring board 1A at the time when the break in the second wiring portion 20Ab is detected when the stretchable wiring board 1A is stretched in the length direction L, that is, before the first wiring portion 20Aa is excessively stretched in the length direction L. In other words, when the stretchable wiring board 1A is used, the user can be prompted to stop using the stretchable wiring board 1A before the first wiring portion 20Aa generates excessive heat due to the first wiring portion 20Aa being excessively stretched in the length direction L when the stretchable wiring board 1A is stretched in the length direction L. Therefore, when the stretchable wiring board 1A is used, not only the first wiring portion 20Aa is prevented from generating excessive heat, but also the excessive heat generated by the first wiring portion 20Aa is prevented from being exposed to the user's body, resulting in increased safety.

[0064] As described above, according to the stretchable wiring board 1A, it is possible to realize a stretchable wiring board capable of safely detecting an excessively stretched state.

[0065] As described above, the narrow portion 11A corresponds to the portion of the stretchable substrate 10A that has the smallest cross-sectional area when viewed in a cross section perpendicular to the longitudinal direction L. Therefore, when the stretchable wiring board 1A is stretched in the longitudinal direction L, stress tends to concentrate in the narrow portion 11A in the stretchable substrate 10A, and as a result, the narrow portion 11A stretches more easily than other portions.

[0066] In contrast, in the stretchable wiring board 1A, the second wiring portion 20Ab is provided at a position overlapping the narrow portion 11A when viewed from the thickness direction T. That is, in the stretchable wiring board 1A, the second wiring portion 20Ab, which will be first to break when the wiring member 20A is stretched in the length direction L, is provided in the narrow portion 11A, which will be stretched the most when the stretchable base material 10A is stretched in the length direction L. Therefore, according to the stretchable wiring board 1A in which the second wiring portion 20Ab is provided in the narrow portion 11A, the second wiring portion 20Ab is more likely to break earlier when stretched in the length direction L compared to a stretchable wiring board in which the second wiring portion 20Ab is not provided in the narrow portion 11A, so that in addition to making it easier to detect an excessively stretched state of the entire stretchable wiring board, the excessively stretched state of the stretchable wiring board can be detected earlier.

[0067] In the example shown in FIG. 1, the second wiring portion 20Ab is provided at a position overlapping the narrow portion 11A when viewed from the thickness direction T, and also at a position not overlapping the narrow portion 11A when viewed from the thickness direction T.

[0068] The second wiring portion 20Ab may be provided only at a position overlapping the narrow portion 11A when viewed from the thickness direction T.

[0069] 1, the stretchable substrate 10A has only one narrow portion 11A, but may have multiple narrow portions. When the stretchable substrate 10A has multiple narrow portions 11A, the second wiring portion 20Ab is preferably provided at a position overlapping each narrow portion 11A when viewed from the thickness direction T. In this case, it becomes easier to detect a break in the second wiring portion 20Ab overlapping each narrow portion 11A, so that an excessively stretched state of the entire stretchable wiring board 1A can be reliably detected.

[0070] When the stretchable substrate 10A has a plurality of narrow portions 11A, the second wiring portion 20Ab may be provided at a position overlapping some of the narrow portions 11A when viewed in the thickness direction T.

[0071] Note that, for example, when the narrow portion 11A is fixed to the human body with a reinforcing material such as resin, there is a possibility that it will not be the most stretchable portion when the stretchable substrate 10A is stretched in the length direction L. In this way, even when the narrow portion 11A is not the most stretchable portion of the stretchable substrate 10A, by providing the second wiring portion 20Ab at a position overlapping the portion of the entire stretchable substrate 10A that stretches mechanically most softly when viewed from the thickness direction T, it becomes easier to detect an excessively stretched state of the entire stretchable wiring board 1A, and in addition, it is possible to detect an excessively stretched state of the stretchable wiring board 1A more quickly.

[0072] In the example shown in FIG. 1, the second wiring portion 20Ab is provided so as to surround the first wiring portion 20Aa when viewed from the thickness direction T. That is, in the example shown in FIG. 1, the second wiring portion 20Ab is provided outside the first wiring portion 20Aa, more specifically, on the outer edge side of the stretchable substrate 10A than the first wiring portion 20Aa, when viewed from the thickness direction T. As shown in FIG. 1, when the second wiring portion 20Ab is provided on the outer edge of the stretchable substrate 10A, the second wiring portion 20Ab expands the area in which an excessively stretched state of the stretchable wiring board 1A can be detected, making it easier to detect an excessively stretched state of the stretchable wiring board 1A.

[0073] Note that the second wiring portion 20Ab does not have to be provided so as to surround the first wiring portion 20Aa when viewed from the thickness direction T. In other words, the second wiring portion 20Ab does not have to be provided outside the first wiring portion 20Aa, more specifically, on the outer edge side of the stretchable substrate 10A than the first wiring portion 20Aa, when viewed from the thickness direction T.

[0074] In the example shown in Fig. 1, the second wiring part 20Ab is not electrically connected to an electronic component. That is, in the example shown in Fig. 1, the second wiring part 20Ab does not form an electrical path to an external electronic component. In this case, a terminal of a resistance meter (not an electronic component), which is a measuring device, is connected to the second wiring part 20Ab to measure the resistance of the second wiring part 20Ab at any time, thereby detecting a break in the second wiring part 20Ab.

[0075] The second wiring portion 20Ab may be electrically connected to an electronic component. That is, the second wiring portion 20Ab may form an electrical path to an external electronic component. In this case, by using, for example, a light-emitting diode as the electronic component electrically connected to the second wiring portion 20Ab, it becomes possible to constantly check whether the second wiring portion 20Ab is disconnected based on whether the light-emitting diode is lit.

[0076] Below, we will describe an example of a configuration in which the tensile strength of the second wiring portion 20Ab in the longitudinal direction L of the wiring member 20A is lower than the tensile strength of the portion other than the second wiring portion 20Ab including the first wiring portion 20Aa in the longitudinal direction L, that is, lower than the tensile strength of the first wiring portion 20Aa in the longitudinal direction L.

[0077] When viewed in a cross section perpendicular to the length direction L of the wiring member 20A, the cross-sectional area of ​​the second wiring portion 20Ab is preferably smaller than the cross-sectional area of ​​the first wiring portion 20Aa.

[0078] When the cross-sectional area of ​​the second wiring portion 20Ab is smaller than the cross-sectional area of ​​the first wiring portion 20Aa, the cross-sectional area of ​​the second wiring portion 20Ab is preferably 10% or more and 90% or less of the cross-sectional area of ​​the first wiring portion 20Aa.

[0079] When viewed in a cross section perpendicular to the longitudinal direction L of the wiring member 20A, it is preferable that the cross-sectional area of ​​the second wiring portion 20Ab in the wiring member 20A is smaller than the cross-sectional area of ​​the portion other than the second wiring portion 20Ab, including the first wiring portion 20Aa.

[0080] In the stretchable wiring board 1A, by determining in advance the relationship between the cross-sectional area of ​​the wiring portion and the breaking elongation rate in the longitudinal direction L of the wiring portion and then setting the cross-sectional area of ​​the second wiring portion 20Ab as described above, it is possible to adjust the timing at which the second wiring portion 20Ab breaks when the stretchable wiring board 1A is stretched in the longitudinal direction L, i.e., the timing at which an excessively elongated state of the stretchable wiring board 1A is detected.

[0081] The cross-sectional areas of the first wiring portion 20Aa and the second wiring portion 20Ab may be the same.

[0082] The dimension of the second wiring portion 20Ab in the width direction W is preferably smaller than the dimension of the first wiring portion 20Aa in the width direction W. In this case, for example, even if the dimensions of the first wiring portion 20Aa and the second wiring portion 20Ab in the thickness direction T are the same, the cross-sectional area of ​​the second wiring portion 20Ab can be smaller than the cross-sectional area of ​​the first wiring portion 20Aa.

[0083] If the dimension of the second wiring portion 20Ab in the width direction W is smaller than the dimension of the first wiring portion 20Aa in the width direction W, it is preferable that the dimension of the second wiring portion 20Ab in the width direction W is 10% or more and 90% or less of the dimension of the first wiring portion 20Aa in the width direction W.

[0084] In the wiring member 20A, the dimension in the width direction W of the second wiring portion 20Ab is preferably smaller than the dimension in the width direction W of the portion other than the second wiring portion 20Ab, including the first wiring portion 20Aa.

[0085] In the stretchable wiring board 1A, by determining in advance the relationship between the dimension of the wiring portion in the width direction W and the breaking elongation rate in the length direction L of the wiring portion, and then setting the dimension of the second wiring portion 20Ab in the width direction W as described above, it is possible to adjust the timing at which the second wiring portion 20Ab breaks when the stretchable wiring board 1A is stretched in the length direction L, i.e., the timing at which an excessively elongated state of the stretchable wiring board 1A is detected.

[0086] The first wiring portion 20Aa and the second wiring portion 20Ab may have the same dimensions in the width direction W. In this case, the first wiring portion 20Aa and the second wiring portion 20Ab can be easily formed under the same conditions, which makes it easier to improve the manufacturing efficiency of the stretchable wiring board 1A.

[0087] The dimension of the second wiring portion 20Ab in the thickness direction T is preferably smaller than the dimension of the first wiring portion 20Aa in the thickness direction T. In this case, for example, even if the dimensions of the first wiring portion 20Aa and the second wiring portion 20Ab in the width direction W are the same, the cross-sectional area of ​​the second wiring portion 20Ab can be smaller than the cross-sectional area of ​​the first wiring portion 20Aa.

[0088] If the dimension of the second wiring portion 20Ab in the thickness direction T is smaller than the dimension of the first wiring portion 20Aa in the thickness direction T, it is preferable that the dimension of the second wiring portion 20Ab in the thickness direction T is 30% or more and 90% or less of the dimension of the first wiring portion 20Aa in the thickness direction T.

[0089] In the wiring member 20A, the dimension in the thickness direction T of the second wiring portion 20Ab is preferably smaller than the dimension in the thickness direction T of the portion other than the second wiring portion 20Ab, including the first wiring portion 20Aa.

[0090] In the stretchable wiring board 1A, by determining in advance the relationship between the dimension of the wiring portion in the thickness direction T and the breaking elongation rate in the length direction L of the wiring portion, and then setting the dimension of the second wiring portion 20Ab in the thickness direction T as described above, it is possible to adjust the timing at which the second wiring portion 20Ab breaks when the stretchable wiring board 1A is stretched in the length direction L, i.e., the timing at which an excessively elongated state of the stretchable wiring board 1A is detected.

[0091] The first wiring portion 20Aa and the second wiring portion 20Ab may have the same dimensions in the thickness direction T. In this case, the first wiring portion 20Aa and the second wiring portion 20Ab can be easily formed under the same conditions, for example, by using the same screen printing plate, and therefore the manufacturing efficiency of the stretchable wiring board 1A can be easily improved.

[0092] When the stretchable wiring 21Aa, the stretchable wiring 21Ab, and the stretchable wiring 21Ac are formed by applying a conductive paste using a screen printing method or the like, the dimensions of the first wiring portion 20Aa and the second wiring portion 20Ab in the thickness direction T can be adjusted by means such as applying the conductive paste multiple times.

[0093] The material of the second wiring portion 20Ab may be different from the material of the first wiring portion 20Aa. In this case, the extensibility of the material of the second wiring portion 20Ab is preferably lower than that of the material of the first wiring portion 20Aa. In addition, the elongation rate of the material of the second wiring portion 20Ab when the same load is applied is preferably lower than that of the material of the first wiring portion 20Aa. In these cases, for example, even if the cross-sectional areas of the first wiring portion 20Aa and the second wiring portion 20Ab are the same, it is possible to make the tensile strength in the length direction L of the second wiring portion 20Ab lower than the tensile strength in the length direction L of the first wiring portion 20Aa. For example, by forming the second wiring portion 20Ab using a thermosetting paste that generally has a low breaking elongation rate, the breaking elongation rate in the length direction L of the second wiring portion 20Ab can be adjusted to be low, so that the tensile strength in the length direction L of the second wiring portion 20Ab can be made lower than the tensile strength in the length direction L of the first wiring portion 20Aa. In this way, by using the second wiring portion 20Ab whose breaking elongation rate in the length direction L is adjusted to be low, even a small elongated state of the stretchable wiring board 1A can be detected.

[0094] In the wiring member 20A, the extensibility of the constituent material of the second wiring portion 20Ab is preferably lower than the extensibility of the constituent material of the portion other than the second wiring portion 20Ab including the first wiring portion 20Aa. Moreover, in the wiring member 20A, when the same load is applied, the extensibility of the constituent material of the second wiring portion 20Ab is preferably lower than the extensibility of the constituent material of the portion other than the second wiring portion 20Ab including the first wiring portion 20Aa.

[0095] The breaking elongation rate in the length direction L of the second wiring portion 20Ab is preferably lower than the breaking elongation rate in the length direction L of the first wiring portion 20Aa.

[0096] The breaking elongation rate in the length direction L of the second wiring portion 20Ab is preferably 10% or more and 90% or less of the breaking elongation rate in the length direction L of the first wiring portion 20Aa.

[0097] In the wiring member 20A, the breaking elongation rate in the length direction L of the second wiring portion 20Ab is preferably lower than the breaking elongation rate in the length direction L of the portion other than the second wiring portion 20Ab, including the first wiring portion 20Aa.

[0098] The stretchable wiring board 1A may further have an electrode connected to at least one of the first wiring portion 20Aa, the stretchable wiring 21Aa and the stretchable wiring 21Ab in the example shown in FIG. 1. The stretchable wiring board 1A can function as a sensor by being attached to the human body via such an electrode. In this case, the stretchable wiring board 1A can detect, for example, that the first wiring portion 20Aa is in an excessively stretched state before it is broken due to excessive stretching in the length direction L, that is, before an abnormality occurs in the sensor. This makes it possible to prompt the user to stop using the stretchable wiring board 1A before an abnormality occurs in the sensor, thereby preventing problems such as obtaining erroneous biometric information or being diagnosed based on erroneous biometric information.

[0099] The electrode is preferably a gel electrode. The use of a gel electrode makes it easier to attach the elastic wiring board 1A to the human body. The gel electrode is made of a conductive gel material that contains, for example, water, alcohol, a moisturizer, an electrolyte, and the like. Examples of such gel materials include hydrogels.

[0100] [Modification of the first embodiment] The stretchable wiring board of the modified example of the first embodiment of the present invention further comprises a protective member that covers at least one of the first main surface and the second main surface of the stretchable base material. Apart from this, the stretchable wiring board of the modified example of the first embodiment of the present invention is similar to the stretchable wiring board of the first embodiment of the present invention.

[0101] FIG. 2 is a schematic perspective view showing an example of a stretchable wiring board according to a modified example of the first embodiment of the present invention.

[0102] The stretchable wiring board 1A' shown in FIG. 2 further comprises a protective member 40A in addition to the stretchable base material 10A and the wiring member 20A.

[0103] The protective member 40A covers at least one of the first main surface 10Aa and the second main surface 10Ab of the stretchable substrate 10A.

[0104] In the example shown in FIG. 2, the protective member 40A covers both the first main surface 10Aa and the second main surface 10Ab of the stretchable substrate 10A.

[0105] The protective member 40A may cover only the first main surface 10Aa of the stretchable substrate 10A, or may cover only the second main surface 10Ab of the stretchable substrate 10A.

[0106] In the example shown in Fig. 2, the protective member 40A is composed of a first protective part 40Aa and a second protective part 40Ab. In the example shown in Fig. 2, the first protective part 40Aa covers the first main surface 10Aa of the stretchable substrate 10A, and the second protective part 40Ab covers the second main surface 10Ab of the stretchable substrate 10A.

[0107] 2, the protective member 40A, more specifically, the first protective portion 40Aa, covers the first main surface 10Aa of the stretchable base material 10A and also covers the wiring member 20A and the electronic component 30. Covering the wiring member 20A and the electronic component 30 with the protective member 40A provides the following effects. The wiring member 20A and the electronic component 30 are protected from the outside. The moisture resistance of the wiring member 20A and the electronic component 30 is improved. Chemical substances used in the wiring member 20A and the electronic components 30 are prevented from coming into contact with the human body. Electric leakage from the wiring member 20A and the electronic component 30 to the human body is prevented.

[0108] The tensile strength in the length direction L of the protective member 40A, and the tensile strength in the length direction L of each of the first protective portion 40Aa and the second protective portion 40Ab in the example shown in FIG. 2, are preferably higher than the tensile strength in the length direction L of the second wiring portion 20Ab. In this case, when the stretchable wiring board 1A' is stretched in the length direction L, the protective member 40A does not break before the second wiring portion 20Ab. In other words, when the stretchable wiring board 1A' is stretched in the length direction L, the protective member 40A does not break at the time when the breakage of the second wiring portion 20Ab is detected. Therefore, when the stretchable wiring board 1A' is used, the user can be prompted to stop using the stretchable wiring board 1A' at the time when the breakage of the second wiring portion 20Ab is detected, that is, before a malfunction occurs such as the chemical substance used in the wiring member 20A and the electronic component 30 coming into contact with the human body or the wiring member 20A and the electronic component 30 leaking electricity to the human body due to the breakage of the protective member 40A. As a result, safety is increased when using the stretchable wiring board 1A' having the protective member 40A.

[0109] The tensile strength in the length direction L of the protective member 40A, and the tensile strength in the length direction L of each of the first protective portion 40Aa and the second protective portion 40Ab in the example shown in Figure 2, is preferably higher than the tensile strength in the length direction L of the first wiring portion 20Aa, and more preferably higher than the tensile strength in the length direction L of all portions of the wiring member 20A.

[0110] The breaking elongation rate in the length direction L of the protective member 40A, and the breaking elongation rate in the length direction L of each of the first protective portion 40Aa and the second protective portion 40Ab in the example shown in FIG. 2, is preferably 200% or more.

[0111] The breaking elongation rate in the length direction L of the protective member 40A, and the breaking elongation rate in the length direction L of each of the first protective portion 40Aa and the second protective portion 40Ab in the example shown in FIG. 2, is preferably 800% or less.

[0112] Examples of materials for the protective member 40A, and for the first protective portion 40Aa and the second protective portion 40Ab in the example shown in FIG. 2, include elastomer resins such as polyvinyl chloride, polyethylene, polystyrene, polycarbonate, polyvinylidene fluoride, polyimide, liquid crystal polymer, polytetrafluoroethylene, phenolic resin, epoxy resin, urethane resin, acrylic resin, silicone resin, and styrene-butadiene resin.

[0113] The protective member 40A is formed, for example, by pressing a film containing the above-mentioned material onto at least one of the first main surface 10Aa and the second main surface 10Ab of the stretchable substrate 10A. Alternatively, the protective member 40A is formed, for example, by applying a slurry containing the above-mentioned material onto at least one of the first main surface 10Aa and the second main surface 10Ab of the stretchable substrate 10A, and then subjecting the applied slurry to a heat treatment or UV treatment. Examples of the method for applying the slurry include a screen printing method, an inkjet method, and a dispense method.

[0114] [Embodiment 2] In the stretchable wiring board of the second embodiment of the present invention, the second wiring portion is provided only at a position that overlaps with the narrow portion when viewed from the thickness direction. The stretchable wiring board of the second embodiment of the present invention is similar to the stretchable wiring board of the first embodiment of the present invention except for this point.

[0115] FIG. 3 is a schematic perspective view showing an example of the stretchable wiring board according to the second embodiment of the present invention.

[0116] The stretchable wiring board 1B shown in FIG. 3 has a stretchable base material 10B and a wiring member 20B.

[0117] The elastic base material 10B has a first main surface 10Ba and a second main surface 10Bb that face each other in the thickness direction T.

[0118] The stretchable substrate 10B has a narrow portion 11B whose cross-sectional area when viewed in a cross section perpendicular to the length direction L is the smallest.

[0119] In the example shown in FIG. 3, the wiring member 20B is provided on the first main surface 10Ba side of the stretchable base material 10B.

[0120] In the example shown in FIG. 3, the wiring member 20B is composed of three elastic wires 21Ba, 21Bb, and 21Bc extending in the planar direction.

[0121] The wiring member 20B includes a first wiring portion 20Ba and a second wiring portion 20Bb, which both extend in the length direction L.

[0122] The first wiring portion 20Ba and the second wiring portion 20Bb are provided on different elastic wires.

[0123] 3, the first wiring portion 20Ba is provided on the elastic wiring 21Ba and the elastic wiring 21Bb, and the second wiring portion 20Bb is provided on the elastic wiring 21Bc. More specifically, the first wiring portion 20Ba corresponds to the entire elastic wiring 21Ba and the elastic wiring 21Bb, and the second wiring portion 20Bb corresponds to a part of the elastic wiring 21Bc.

[0124] In the elastic wiring 21Bc, the second wiring portion 20Bb may be electrically connected to the wiring portion adjacent to the second wiring portion 20Bb. In the elastic wiring 21Bc, the second wiring portion 20Bb may be integrated with the wiring portion adjacent to the second wiring portion 20Bb so that no interface is present, or may not be integrated with the wiring portion adjacent to the second wiring portion 20Bb so that an interface is present.

[0125] Each of the first wiring portion 20Ba, the elastic wiring 21Ba and the elastic wiring 21Bb in the example shown in Fig. 3 is electrically connected to the electronic component 30. That is, the first wiring portion 20Ba constitutes an electrical path to the outside, and in the example shown in Fig. 3, an electrical path to the external electronic component 30.

[0126] In the wiring member 20B, the tensile strength in the length direction L of the second wiring portion 20Bb is lower than the tensile strength in the length direction L of the portion other than the second wiring portion 20Bb, including the first wiring portion 20Ba. In other words, the tensile strength in the length direction L of the second wiring portion 20Bb is not only lower than the tensile strength in the length direction L of the first wiring portion 20Ba, but is also the lowest among the tensile strengths in the length direction L of the wiring member 20B. As a result, when the elastic wiring board 1B is stretched in the length direction L, the second wiring portion 20Bb will not only break before the first wiring portion 20Ba, but will also be the first to break in the wiring member 20B.

[0127] Therefore, according to the stretchable wiring board 1B, by utilizing the fact that the second wiring portion 20Bb is the first to break when stretched in the length direction L, it is possible to realize a stretchable wiring board that can safely detect an excessively stretched state, similar to the stretchable wiring board 1A.

[0128] As described above, the narrow portion 11B corresponds to a portion of the stretchable substrate 10B that has the smallest cross-sectional area when viewed in a cross section perpendicular to the longitudinal direction L. Therefore, when the stretchable wiring board 1B is stretched in the longitudinal direction L, stress tends to concentrate in the narrow portion 11B in the stretchable substrate 10B, and as a result, the narrow portion 11B stretches more easily than other portions.

[0129] In contrast, in the stretchable wiring board 1B, the second wiring portion 20Bb is provided only at a position that overlaps the narrow portion 11B when viewed from the thickness direction T. Therefore, according to the stretchable wiring board 1B, similar to the stretchable wiring board 1A, the second wiring portion 20Bb is more likely to break more quickly when stretched in the length direction L, and therefore an excessively stretched state can be detected more quickly.

[0130] When viewing a cross section perpendicular to the length direction L of the wiring member 20B, in the elastic wiring 21Bc, the cross-sectional area of ​​the second wiring portion 20Bb is preferably smaller than the cross-sectional area of ​​the portion other than the second wiring portion 20Bb.

[0131] In the elastic wiring 21Bc, when the cross-sectional area of ​​the second wiring portion 20Bb is smaller than the cross-sectional area of ​​the portion other than the second wiring portion 20Bb, it is preferable that the cross-sectional area of ​​the second wiring portion 20Bb is 10% or more and 90% or less of the cross-sectional area of ​​the portion other than the second wiring portion 20Bb.

[0132] In the elastic wiring 21Bc, the dimension in the width direction W of the second wiring portion 20Bb is preferably smaller than the dimension in the width direction W of the portion other than the second wiring portion 20Bb.

[0133] In the elastic wiring 21Bc, when the dimension in the width direction W of the second wiring portion 20Bb is smaller than the dimension in the width direction W of the portion other than the second wiring portion 20Bb, it is preferable that the dimension in the width direction W of the second wiring portion 20Bb is 10% or more and 90% or less of the dimension in the width direction W of the portion other than the second wiring portion 20Bb.

[0134] In the elastic wiring 21Bc, the dimension in the thickness direction T of the second wiring portion 20Bb is preferably smaller than the dimension in the thickness direction T of the portion other than the second wiring portion 20Bb.

[0135] In the elastic wiring 21Bc, when the dimension of the second wiring portion 20Bb in the thickness direction T is smaller than the dimension of the portion other than the second wiring portion 20Bb in the thickness direction T, it is preferable that the dimension of the second wiring portion 20Bb in the thickness direction T is 30% or more and 90% or less of the dimension of the portion other than the second wiring portion 20Bb in the thickness direction T.

[0136] In the example shown in FIG. 3, the second wiring portion 20Bb is provided in two locations overlapping the narrow portion 11B when viewed from the thickness direction T, but it may be provided in only one location, or in three or more locations.

[0137] In the example shown in FIG. 3, the dimensions in the length direction L of the second wiring portions 20Bb provided at two locations may be the same as each other or may be different from each other.

[0138] [Modification of the second embodiment] The stretchable wiring board of the modified example of the second embodiment of the present invention further includes a protective member that covers at least one of the first and second main surfaces of the stretchable base material. Apart from this, the stretchable wiring board of the modified example of the second embodiment of the present invention is similar to the stretchable wiring board of the second embodiment of the present invention.

[0139] FIG. 4 is a schematic perspective view showing an example of a stretchable wiring board according to a modified example of the second embodiment of the present invention.

[0140] The stretchable wiring board 1B' shown in FIG. 4 further comprises a protective member 40B in addition to the stretchable base material 10B and the wiring member 20B.

[0141] In the example shown in FIG. 4, the protective member 40B covers both the first main surface 10Ba and the second main surface 10Bb of the stretchable substrate 10B.

[0142] In the example shown in Fig. 4, the protective member 40B is composed of a first protective part 40Ba and a second protective part 40Bb. In the example shown in Fig. 4, the first protective part 40Ba covers the first main surface 10Ba of the stretchable substrate 10B, and the second protective part 40Bb covers the second main surface 10Bb of the stretchable substrate 10B.

[0143] [Embodiment 3] In the stretchable wiring board of the third embodiment of the present invention, the first wiring section and the second wiring section are provided on the same stretchable wiring. The stretchable wiring board of the third embodiment of the present invention is otherwise similar to the stretchable wiring board of the first embodiment of the present invention.

[0144] FIG. 5 is a schematic perspective view showing an example of the stretchable wiring board according to the third embodiment of the present invention.

[0145] The stretchable wiring board 1C shown in FIG. 5 has a stretchable base material 10C and a wiring member 20C.

[0146] The elastic substrate 10C has a first main surface 10Ca and a second main surface 10Cb that face each other in the thickness direction T.

[0147] In the example shown in FIG. 5, the wiring member 20C is provided on the first main surface 10Ca side of the stretchable substrate 10C.

[0148] In the example shown in FIG. 5, the wiring member 20C is composed of two elastic wires, an elastic wire 21Ca and an elastic wire 21Cb, which extend in the planar direction.

[0149] The wiring member 20C includes a first wiring portion 20Ca and a second wiring portion 20Cb, which both extend in the length direction L.

[0150] The first wiring portion 20Ca and the second wiring portion 20Cb are provided on the same elastic wire.

[0151] 5, the first wiring portion 20Ca and the second wiring portion 20Cb are provided in the elastic wiring 21Ca and are also provided in the elastic wiring 21Cb. More specifically, the first wiring portion 20Ca corresponds to a part of each of the elastic wiring 21Ca and the elastic wiring 21Cb, and the second wiring portion 20Cb corresponds to the remaining part of each of the elastic wiring 21Ca and the elastic wiring 21Cb.

[0152] In each of the elastic wiring 21Ca and the elastic wiring 21Cb, the second wiring portion 20Cb may be electrically connected to the first wiring portion 20Ca. In each of the elastic wiring 21Ca and the elastic wiring 21Cb, the second wiring portion 20Cb may be integrated with the first wiring portion 20Ca so that no interface is present, or may not be integrated with the first wiring portion 20Ca so that an interface is present.

[0153] The first wiring portion 20Ca is electrically connected to the electronic component 30. That is, the first wiring portion 20Ca constitutes an electrical path to the outside, that is, an electrical path to the external electronic component 30 in the example shown in FIG.

[0154] The second wiring portion 20Cb is connected to the first wiring portion 20Ca.

[0155] In the wiring member 20C, the tensile strength in the length direction L of the second wiring portion 20Cb is lower than the tensile strength in the length direction L of the portion other than the second wiring portion 20Cb including the first wiring portion 20Ca. In other words, the tensile strength in the length direction L of the second wiring portion 20Cb is not only lower than the tensile strength in the length direction L of the first wiring portion 20Ca, but is also the lowest among the tensile strengths in the length direction L of the wiring member 20C. As a result, when the stretchable wiring board 1C is stretched in the length direction L, the second wiring portion 20Cb will not only break before the first wiring portion 20Ca, but will also be the first to break in the wiring member 20C.

[0156] Therefore, according to the stretchable wiring board 1C, by utilizing the fact that the second wiring portion 20Cb is the first to break when stretched in the length direction L, it is possible to realize a stretchable wiring board that can safely detect an excessively stretched state, similar to the stretchable wiring board 1A.

[0157] The dimension of the second wiring portion 20Cb in the length direction L is preferably 1% or more and 50% or less of the dimension of the first wiring portion 20Ca in the length direction L. When the dimension of the second wiring portion 20Cb in the length direction L is within the above range relative to the dimension of the first wiring portion 20Ca in the length direction L, it becomes easy to detect an excessively stretched state of the stretchable wiring board 1C, and it becomes easy to design the resistance of the stretchable wiring.

[0158] 5, the stretchable base material 10C has a narrow portion 11C whose cross-sectional area is the smallest when viewed in a cross section perpendicular to the length direction L, and the second wiring portion 20Cb is provided at a position overlapping the narrow portion 11C when viewed in the thickness direction T. Therefore, according to the stretchable wiring board 1C, similar to the stretchable wiring board 1A, when stretched in the length direction L, the second wiring portion 20Cb is more likely to break at an earlier stage, and therefore an excessively stretched state can be detected at an earlier stage.

[0159] In the example shown in FIG. 5, the second wiring portion 20Cb is provided in two locations that overlap the narrow portion 11C when viewed from the thickness direction T, but it may be provided in only one location, or in three or more locations.

[0160] In the example shown in FIG. 5, the dimensions in the length direction L of the second wiring portions 20Cb provided at two locations may be the same as each other or may be different from each other.

[0161] [Modification of the third embodiment] The stretchable wiring board of the modified example of the third embodiment of the present invention further includes a protective member that covers at least one of the first and second main surfaces of the stretchable base material. Apart from this, the stretchable wiring board of the modified example of the third embodiment of the present invention is similar to the stretchable wiring board of the third embodiment of the present invention.

[0162] FIG. 6 is a schematic perspective view showing an example of a stretchable wiring board according to a modified example of the third embodiment of the present invention.

[0163] The stretchable wiring board 1C' shown in FIG. 6 further comprises a protective member 40C in addition to the stretchable base material 10C and the wiring member 20C.

[0164] In the example shown in FIG. 6, the protective member 40C covers both the first main surface 10Ca and the second main surface 10Cb of the stretchable substrate 10C.

[0165] In the example shown in Fig. 6, the protective member 40C is composed of a first protective part 40Ca and a second protective part 40Cb. In the example shown in Fig. 6, the first protective part 40Ca covers the first main surface 10Ca of the stretchable substrate 10C, and the second protective part 40Cb covers the second main surface 10Cb of the stretchable substrate 10C.

[0166] [Embodiment 4] The stretchable wiring board of embodiment 4 of the present invention further includes a detection unit that checks the energized state of the second wiring section during use of the stretchable wiring board, a determination unit that checks whether or not the second wiring section has been disconnected based on information about the energized state of the second wiring section confirmed by the detection unit, and a transmission unit that transmits information that a disconnection of the second wiring section has been detected.

[0167] FIG. 7 is a flowchart showing an example of the operation of the stretchable wiring board according to the fourth embodiment of the present invention.

[0168] First, a user starts to use the stretchable wiring board attached to his or her body. At this time, the stretchable wiring board is stretched in the length direction.

[0169] Next, in step S11 shown in FIG. 7, the detection unit checks the energization state of the second wiring portion while the stretchable wiring board is in use.

[0170] At this time, for example, a resistance meter may be used as the detection unit to measure the resistance of the second wiring portion at any time, thereby checking the energized state of the second wiring portion.

[0171] Also, for example, a detection circuit having a light emitting diode connected to the second wiring portion as the detection portion may be provided, and the energization state of the second wiring portion may be confirmed by constantly checking the lighting state of the light emitting diode.

[0172] Next, in step S12 shown in FIG. 7, the determination unit determines whether or not the second wiring portion is disconnected based on the information on the energized state of the second wiring portion confirmed by the detection unit.

[0173] In this case, for example, if a resistance meter is used as the detection unit to measure the resistance of the second wiring portion from time to time, the judgment unit may determine that the second wiring portion is broken when the resistance of the second wiring portion becomes equal to or greater than a threshold value.

[0174] In addition, for example, in the case where a detection circuit in which a light-emitting diode is connected to the second wiring section is provided as a detection section and the lighting state of the light-emitting diode is checked at any time, the judgment section may judge that the second wiring section has been broken when the light-emitting diode changes from a lighting state to an off state.

[0175] The determination unit may be, for example, a resistance meter serving as the detection unit, a determination circuit connected to a detection circuit, etc.

[0176] If it is not determined that the second wiring portion is disconnected, the determination process by the determination portion in step S12 described above is performed again.

[0177] Next, when the determination unit determines that the second wiring unit is disconnected, in step S13 shown in FIG. 7, the transmission unit transmits information that the second wiring unit is disconnected.

[0178] In this case, for example, when a detection circuit in which a light emitting diode is connected to the second wiring portion is provided as a detection portion, the light emitting diode may be changed from a lit state to an unlit state to notify the user, thereby transmitting information that a break in the second wiring portion has been detected. In this case, the light emitting diode connected to the second wiring portion functions as a transmission portion.

[0179] Also, for example, the transmitting unit may be provided with an alert circuit that transmits an alert when the second wiring unit is disconnected, and the alert transmitted by the alert circuit may be displayed to the user to transmit information that a disconnection in the second wiring unit has been detected. Examples of the manner of transmitting the alert include displaying an alert message on a monitor or the like, generating an alert sound, turning on an alert lamp, and the like.

[0180] The user can stop using the stretchable wiring board by checking the information that the disconnection of the second wiring part has been detected, which is transmitted by the transmitting unit in step S13. This allows the user to stop using the stretchable wiring board at the time when the disconnection of the second wiring part is detected, that is, before the first wiring part is excessively stretched in the length direction.

[0181] [Modification of the fourth embodiment] The stretchable wiring board of the modified embodiment of the fourth embodiment of the present invention further includes a control unit that stops the current supply to the first wiring unit in conjunction with the transmission of information that a break in the second wiring unit has been detected by the transmission unit. Apart from this, the stretchable wiring board of the modified embodiment of the fourth embodiment of the present invention is similar to the stretchable wiring board of the fourth embodiment of the present invention.

[0182] FIG. 8 is a flowchart showing an example of the operation of the stretchable wiring board according to the modified example of the fourth embodiment of the present invention.

[0183] Steps S11, S12, and S13 shown in FIG. 8 are similar to those in FIG.

[0184] Next, in step S14 shown in FIG. 8, in response to the transmission unit transmitting the information that a break in the second wiring unit has been detected, the control unit stops the supply of current to the first wiring unit.

[0185] The control unit may be, for example, a control circuit that can stop the current supply to the first wiring unit in conjunction with the transmission of information that the disconnection of the second wiring unit has been detected by the transmission unit. The control circuit may or may not be directly connected to the first wiring unit.

[0186] The timing at which the control unit stops supplying current to the first wiring section may be the same timing at which the transmitting unit transmits the information that a break in the second wiring section has been detected, or may be the timing after the transmitting unit transmits the information that a break in the second wiring section has been detected.

[0187] In step S14, the control unit stops the supply of current to the first wiring unit, thereby forcibly stopping the use of the stretchable wiring board. This makes it possible to reliably stop the use of the stretchable wiring board at the time when a break in the second wiring unit is detected, that is, before the first wiring unit is excessively stretched in the length direction.

[0188] In each of the above embodiments, the stretchable wiring board is stretched in the length direction when the stretchable wiring board is used. However, the stretchable wiring board may be stretched in a surface direction other than the length direction (e.g., the width direction) in addition to the length direction.

[0189] The present specification discloses the following:

[0190] <1> An elastic substrate having a first main surface and a second main surface opposed to each other in a thickness direction; A wiring member provided on at least the first main surface side of the elastic base material and extending in a surface direction including a length direction perpendicular to the thickness direction and a width direction perpendicular to the thickness direction and the length direction, the wiring member being composed of at least one elastic wiring; the wiring member includes a first wiring portion and a second wiring portion that extend together in the longitudinal direction, the first wiring portion constitutes an electrical path to the outside, The stretchable wiring board, characterized in that in the wiring member, the tensile strength of the second wiring portion in the longitudinal direction is lower than the tensile strength of a portion other than the second wiring portion, including the first wiring portion, in the longitudinal direction.

[0191] <2> The first wiring portion and the second wiring portion are provided on different elastic wirings, <1> The stretchable wiring board according to claim 1.

[0192] <3> The first wiring portion and the second wiring portion are provided on the same elastic wiring. <1> The stretchable wiring board according to claim 1.

[0193] <4> the dimension of the second wiring portion in the length direction is 1% or more and 50% or less of the dimension of the first wiring portion in the length direction; <3> The stretchable wiring board according to claim 1.

[0194] <5> When viewed in a cross section perpendicular to the longitudinal direction of the wiring member, a cross-sectional area of ​​the second wiring portion is smaller than a cross-sectional area of ​​the first wiring portion. <1> ~ <4> The stretchable wiring board according to any one of the preceding claims.

[0195] <6> The dimension of the second wiring portion in the width direction is smaller than the dimension of the first wiring portion in the width direction. <5> The stretchable wiring board according to claim 1.

[0196] <7> a dimension of the second wiring portion in the thickness direction is smaller than a dimension of the first wiring portion in the thickness direction; <5> or <6> The stretchable wiring board according to claim 1.

[0197] <8> The second wiring portion is made of a material different from that of the first wiring portion. <1> ~ <7> The stretchable wiring board according to any one of the preceding claims.

[0198] <9> The stretchable substrate has a narrow portion having a minimum cross-sectional area when viewed in a cross section perpendicular to the longitudinal direction, the second wiring portion is provided at a position overlapping the narrow portion when viewed in the thickness direction; <1> ~ <8> The stretchable wiring board according to any one of the preceding claims.

[0199] <10> Further comprising a protective member covering at least one of the first main surface and the second main surface of the elastic substrate. <1> ~ <9> The stretchable wiring board according to any one of the preceding claims.

[0200] <11> A detection unit that checks the energization state of the second wiring portion during use of the stretchable wiring board; a determination unit that determines whether or not the second wiring portion is disconnected based on information on the current-carrying state of the second wiring portion confirmed by the detection unit; and and a transmitting unit that transmits information that a break in the second wiring portion has been detected. <1> ~ <10> The stretchable wiring board according to any one of the preceding claims.

[0201] <12> The power supply device further includes a control unit that stops a current supply to the first wiring unit in response to the transmission unit transmitting information that a break in the second wiring unit has been detected. <11> The stretchable wiring board according to claim 1. [Explanation of symbols]

[0202] 1A, 1A', 1B, 1B', 1C, 1C' Stretchable wiring board 10A, 10B, 10C Stretchable base material 10Aa, 10Ba, 10Ca First main surface 10Ab, 10Bb, 10Cb 2nd principal surface 11A, 11B, 11C Narrow section 20A, 20B, 20C Wiring materials 20Aa, 20Ba, 20Ca 1st wiring section 20Ab, 20Bb, 20Cb 2nd wiring section 21Aa, 21Ab, 21Ac, 21Ba, 21Bb, 21Bc, 21Ca, 21Cb Stretchable wiring 30 Electronic Components 40A, 40B, 40C Protective materials 40Aa, 40Ba, 40Ca 1st protection part 40Ab, 40Bb, 40Cb 2nd protection section L Length direction S11, S12, S13, S14 steps T thickness direction W Width direction

Claims

1. An elastic substrate having a first main surface and a second main surface opposed to each other in a thickness direction; A wiring member provided on at least the first main surface side of the elastic base material and extending in a surface direction including a length direction perpendicular to the thickness direction and a width direction perpendicular to the thickness direction and the length direction, the wiring member being composed of at least one elastic wiring; the wiring member includes a first wiring portion and a second wiring portion that extend together in the longitudinal direction, the first wiring portion forms an electrical path to an external device; In the wiring member, a tensile strength in the length direction of the second wiring portion is lower than a tensile strength in the length direction of a portion other than the second wiring portion, the portion including the first wiring portion; A stretchable wiring board, characterized in that a constituent material of the second wiring portion is different from a constituent material of the first wiring portion.

2. An elastic substrate having a first principal surface and a second principal surface opposed to each other in a thickness direction; A wiring member provided on at least the first main surface side of the elastic base material and extending in a surface direction including a length direction perpendicular to the thickness direction and a width direction perpendicular to the thickness direction and the length direction, the wiring member being composed of at least one elastic wiring; the wiring member includes a first wiring portion and a second wiring portion that extend together in the longitudinal direction, the first wiring portion forms an electrical path to an external device; In the wiring member, a tensile strength in the length direction of the second wiring portion is lower than a tensile strength in the length direction of a portion other than the second wiring portion, the portion including the first wiring portion; The stretchable substrate has a narrow portion having a minimum cross-sectional area when viewed in a cross section perpendicular to the longitudinal direction, The stretchable wiring board, characterized in that the second wiring portion is provided at a position overlapping the narrow portion when viewed from the thickness direction.

3. The stretchable wiring board according to claim 1 or 2, wherein the first wiring portion and the second wiring portion are provided on different stretchable wirings.

4. The stretchable wiring board according to claim 1 or 2, wherein the first wiring portion and the second wiring portion are provided on the same stretchable wiring.

5. The stretchable wiring board according to claim 4 , wherein the dimension of the second wiring portion in the length direction is 1% or more and 50% or less of the dimension of the first wiring portion in the length direction.

6. The stretchable wiring board according to claim 1 or 2, wherein when viewed in a cross section perpendicular to the longitudinal direction of the wiring member, a cross-sectional area of ​​the second wiring portion is smaller than a cross-sectional area of ​​the first wiring portion.

7. The stretchable wiring board according to claim 6 , wherein a dimension of the second wiring portion in the width direction is smaller than a dimension of the first wiring portion in the width direction.

8. The stretchable wiring board according to claim 6 , wherein a dimension of the second wiring portion in the thickness direction is smaller than a dimension of the first wiring portion in the thickness direction.

9. The stretchable substrate has a narrow portion having a minimum cross-sectional area when viewed in a cross section perpendicular to the longitudinal direction, The stretchable wiring board according to claim 1 , wherein the second wiring portion is provided at a position overlapping the narrow portion when viewed in the thickness direction.

10. The stretchable wiring board according to claim 1 or 2, further comprising a protective member covering at least one of the first main surface and the second main surface of the stretchable base material.

11. A detection unit that checks the energization state of the second wiring portion during use of the stretchable wiring board; a determination unit that determines whether or not the second wiring portion is disconnected based on information on the current-carrying state of the second wiring portion confirmed by the detection unit; and The stretchable wiring board according to claim 1 or 2, further comprising a transmitter that transmits information that a break in the second wiring portion has been detected.

12. The stretchable wiring board according to claim 11, further comprising a control unit that stops the supply of current to the first wiring unit in response to the transmission of information from the transmission unit that a break in the second wiring unit has been detected.

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