Stretchable device

Abstract

Provided is a stretchable device comprising: a stretchable first substrate having a first main surface; a wiring provided on the first main surface of the first substrate; and a protective layer covering at least a part of the first main surface of the first substrate and at least a part of the wiring. A peeling strength between the wiring and the first substrate is larger than a peeling strength between the protective layer and the first substrate.

Description

stretchable devices

[0001] The present disclosure relates to stretchable devices.

[0002] Conventionally, a stretchable device has been used in which wiring is provided on a stretchable substrate and a protective layer is further provided to cover the wiring. For example, International Publication No. 2021 / 235282 (Patent Document 1) describes a stretchable device having a stretchable substrate having a first main surface, wiring provided on the first main surface of the stretchable substrate, and a protective layer covering the wiring provided on the first main surface of the stretchable substrate, as shown in FIG.

[0003] International Publication No. 2021 / 235282

[0004] In conventional stretchable devices, when an external force is applied to the stretchable device, the wiring stretches in close contact with the stretchable substrate. However, the stretching during use can cause stress to concentrate at the interface between the wiring and the substrate, which can lead to separation between the wiring and the substrate.

[0005] An object of the present disclosure is to provide a stretchable device that can suppress peeling between wiring and a substrate.

[0006] In order to solve the above problem, a stretchable device according to one aspect of the present disclosure comprises: a stretchable first substrate having a first main surface; wiring provided on the first main surface of the first substrate; and a protective layer covering at least a portion of the first main surface of the first substrate and at least a portion of the wiring, wherein the peel strength between the wiring and the first substrate is greater than the peel strength between the protective layer and the first substrate.

[0007] Because the peel strength between the wiring and the first substrate is greater than the peel strength between the protective layer and the first substrate, when an external force is applied to the stretchable device, the protective layer and the first substrate peel off before the wiring and the first substrate peel off. This peeled portion allows the first substrate to expand and contract significantly and absorb the external force. As a result, the load on the wiring against the external force is reduced, and it is possible to prevent the wiring from peeling off from the first substrate and breaking.

[0008] According to the present disclosure, it is possible to provide a stretchable device that can suppress peeling between wiring and a substrate.

[0009] FIG. 1 is a top view of a stretchable device of a first embodiment. FIG. 2 is an XZ sectional view of the stretchable device of the first embodiment. FIG. 3 is a schematic sectional view illustrating the stretchable device of the first embodiment. FIG. 4 is a schematic view illustrating a method for measuring peel strength. FIG. 5 is a schematic view illustrating a method for measuring peel strength. FIG. 6 is a schematic view illustrating a method for measuring peel strength. FIG. 7 is an XZ sectional view of a stretchable device of a second embodiment. FIG. 8 is an XZ sectional view of a stretchable device of a third embodiment. FIG. 9 is a top view of a stretchable device of a fourth embodiment. FIG. 10 is an XZ sectional view of a stretchable device of the fourth embodiment. FIG. 11 is an XZ sectional view of a stretchable device of a fifth embodiment. FIG. 12 is a top view of a stretchable device of a sixth embodiment. FIG. 13 is an XZ sectional view of a stretchable device of the sixth embodiment.

[0010] Below, a stretchable device according to one aspect of the present disclosure will be described in detail with reference to the illustrated embodiments. In each embodiment, differences from previous embodiments will be mainly described. In particular, similar effects resulting from similar configurations will not be mentioned in each embodiment. Furthermore, the size and size ratio of components shown in the drawings are not necessarily precise. In each drawing, substantially identical components are designated by the same reference numerals, and redundant explanations may be omitted or simplified.

[0011] [First embodiment] (Structure) The structure of a stretchable device 100 according to a first embodiment will be described with reference to Fig. 1 and Fig. 2. Fig. 1 is a top view of the stretchable device 100. Fig. 2 is a cross-sectional view of the stretchable device 100 taken along the line II-II in Fig. 1.

[0012] The stretchable device 100 includes a stretchable first substrate 1, two wires 2 provided on a first main surface 1a of the first substrate 1, and a protective layer 3 that covers the first main surface 1a of the first substrate 1 and the wires 2. The stretchable device 100 is used, for example, for circuit connection with a printed circuit board or a flexible substrate. Note that the shape of the stretchable device 100 is not particularly limited.

[0013] Furthermore, "above" in this specification does not have to coincide with the up and down when the stretchable device 100 is in use. More specifically, "above the main surface of the first substrate 1" does not refer to an absolute direction such as vertically upward as defined by the direction of gravity, but rather refers to a direction toward the outside of the outside and inside with the main surface of the first substrate 1 as a boundary, based on the main surface of the first substrate 1. Furthermore, "above" with respect to an element includes not only an above position separated from the element, i.e., an above position via another object on the element or an above position spaced apart, but also a position directly above the element (on).

[0014] As shown in the drawings, for the sake of convenience, the direction perpendicular to the extension direction of the wiring 2 will be referred to as the X direction. The extension direction of the wiring 2 will be referred to as the Y direction. The thickness direction of the wiring 2 will be referred to as the Z direction. The X direction, Y direction, and Z direction are mutually orthogonal directions, and when arranged in the order X, Y, Z, they form a right-handed system.

[0015] The first substrate 1 is a support material such as a film made of a stretchable resin material. The first substrate 1 is in the form of a sheet or film. The first substrate 1 has a first main surface 1a and a second main surface 1b located on opposite sides of each other.

[0016] The first substrate 1 is stretchable. The stretchability of the first substrate 1 does not inhibit the stretching of the wiring 2, and the risk of breakage due to stretching during use of the stretchable device 100 can be reduced. The thickness of the first substrate 1 is not particularly limited, but from the viewpoint of not inhibiting the stretching of the surface of a living body when attached to the living body, it is preferably 100 μm or less, and more preferably 1 μm or less. The first substrate 1 may be a laminate of multiple layers.

[0017] Examples of materials for the first substrate 1 include thermoplastic resins. Specifically, the first substrate 1 includes a stretchable resin material, such as at least one selected from the group consisting of acrylic resins, urethane resins, and styrene resins. Examples of urethane resins include thermoplastic polyurethanes. Examples of styrene resins include styrene-butadiene-styrene block copolymers (SBS).

[0018] The wiring 2 has a first surface 2a and a second surface 2b located on opposite sides. The second surface 2b of the wiring 2 is located on the first main surface 1a of the first substrate 1. The two wirings 2 are arranged parallel to each other along the X direction. The shape of the wiring 2 is not particularly limited. The wirings 2 may be arranged facing a direction different from the X direction. The number of wirings 2 is not particularly limited, and may be one, or three or more. The wirings 2 are not limited to the arrangement shown in FIG. 1 , and the extension direction is also not limited. Specifically, the longitudinal direction of the first substrate 1 and the extension direction of the wiring 2 do not have to coincide, and the wirings 2 do not have to extend in one direction.

[0019] The wiring 2 is preferably elastic. The wiring 2 is formed of an electrically conductive material. Examples of the electrically conductive material include metal foils such as silver, copper, and nickel, or a mixture of electrically conductive particles such as silver, copper, and nickel with a resin. Examples of the resin include epoxy resins, urethane resins, acrylic resins, and silicone resins, as well as elastomer resins, which are mixtures of these. The use of such resins ensures elasticity. The average particle size of the electrically conductive particles is not particularly limited, but is preferably 0.01 μm or more and 10 μm or less. The shape of the electrically conductive particles is preferably spherical, but is not limited to spherical shapes. They may also be flat or have protrusions to improve elasticity. The wiring 2 does not necessarily have to be elastic.

[0020] The thickness of the wiring 2 is preferably 100 μm or less, more preferably 50 μm or less. The thickness of the stretchable wiring is more preferably 1 μm or more, and may be 5 μm or more. The thickness, width, and length of the wiring 2 are not particularly limited.

[0021] The protective layer 3 covers a portion of the first main surface 1a of the first substrate 1 and the entire wiring 2. That is, the first main surface 1a has exposed end portions S3. By providing the protective layer 3, the wiring 2 can be protected. The protective layer 3 may cover at least a portion of the first main surface 1a of the first substrate 1 and at least a portion of the wiring 2. The protective layer 3 may be a single layer, or may be a laminate of multiple layers. The material of the protective layer 3 may be the same as or different from the material of the first substrate 1.

[0022] The protective layer 3 is formed, for example, from a resin material or a mixture of a resin material and an inorganic material. Examples of resin materials include silicone-based resins, acrylic-based resins, olefin-based resins such as polyethylene and polypropylene, modified urethane-based resins, urethane-based resins, styrene-based resins, vinyl chloride-based resins, polyester-based resins, and polyamide-based resins. Other resin materials that may be used include fluorine-based, nitrile rubber-based, latex rubber-based, and other elastomer-based resins, epoxy, phenolic, imide-based, rosin, cellulose, polyethylene terephthalate-based, polyethylene naphthalate-based, and polycarbonate-based resins. The material of the protective layer 3 may be the same as the material of the first substrate. The protective layer 3 preferably has insulating properties. Having insulating properties in the protective layer 3 more reliably suppresses ion migration of the wiring 2.

[0023] The protective layer 3 can be provided by applying an insulating paste, for example. The protective layer 3 can also be provided using a sheet material. The insulating paste can be provided on a part of the first main surface 1 a of the first substrate 1 and on the wiring layer 3 by screen printing, gravure printing, inkjet printing, or the like.

[0024] The thickness of the protective layer 3 is preferably 1 μm or more and 100 μm or less, and may be 50 μm or less. By making the thickness of the protective layer 3 1 μm or more, the durability of the protective layer 3 can be ensured. Furthermore, by making the thickness of the protective layer 3 100 μm or less, the overall height can be reduced. Note that when the thickness of the protective layer 3 is not constant, the thickness of the protective layer 3 is the maximum thickness of the protective layer 3.

[0025] The peel strength between the wiring 2 and the first substrate 1 is greater than the peel strength between the protective layer 3 and the first substrate 1. When an external force F1 is applied to the stretchable device 100, the stretchable device 100 stretches and contracts uniformly unless peeling occurs between the protective layer 3 and the first substrate 1. With the above configuration, the protective layer 3 and the first substrate 1 peel off before peeling occurs between the wiring 2 and the first substrate 1, and if peeling occurs between the protective layer 3 and the first substrate 1, the external force F1 can be absorbed at the peeled location. The load on the wiring 2 against the external force F1 is reduced, and it is possible to prevent the wiring 2 from peeling off from the first substrate 1 and breaking.

[0026] Specifically, a case where the stretchable device 100 is stretched will be described with reference to FIGS. 2 and 3. As shown in FIG. 2, in the stretchable device 100, two wires 2 are located on the first main surface 1a of the first substrate 1, and a protective layer 3 is provided on the first main surface 1a so as to cover the two wires 2. As shown in FIG. 3, an external force F1 that stretches the stretchable device 100 left and right is applied to the stretchable device 100 in a cross section perpendicular to the extension direction of the wires 2. Application of the external force F1 may cause peeling at locations with weak peel strength. For example, peeling may occur between the first substrate 1 and the protective layer 3 between the two wires 2 rather than between the wires 2 and the first substrate 1, resulting in a void S. In a cross section perpendicular to the extension direction of the wiring 2, the first main surface 1a has, in the X-axis direction, an exposed end S3, a portion S4 in contact with the protective layer 3 and adjacent to the exposed end S3, a portion S2 in contact with the wiring 2 and adjacent to the portion S4, a portion S1 in contact with the void S and adjacent to the portion S2, a portion S2 in contact with the wiring 2 and adjacent to the portion S1, a portion S4 in contact with the protective layer 3 and adjacent to the portion S2, and an exposed end S3 adjacent to the portion S4, in that order. At the exposed end S3, the first main surface 1a of the first substrate 1 is less constrained by the protective layer 3, allowing for good elongation. Therefore, the portion S1 and the exposed end S3 can elongate significantly and absorb the external force F1. As a result, the load on the wiring 2 against the external force F1 is reduced, preventing the wiring 2 from peeling off from the first substrate 1 and breaking, and protecting the wiring 2. It is believed that the same effects as when the stretchable device 100 is stretched also occur when the stretchable device 100 is contracted. 3 illustrates a case where the entire area between the wires 2 is peeled off and a gap S is formed, but only a portion between the wires 2 may be peeled off. In other words, the portion with relatively low peel strength does not need to be the entire area where the protective layer 3 and the first substrate 1 contact each other, but may be a portion. Similarly, the location of the portion with low peel strength is not limited, and may be in an area other than between the wires 2.

[0027] Figures 4A, 4B, and 4C show a method for measuring the peel strength between the first substrate 1 and the wiring 2. A 180° peel test of adhesive tape was performed with reference to JIS Z 0237, "180° Peel Test for Adhesive Tape," and JIS Z 0238, "Test Method for Heat-Sealed Flexible Packaging Bags and Semi-Rigid Containers," as a method for quantitatively measuring interfacial peel strength. As shown in Figure 4A, a conductive material is applied to the first main surface 1a of the first substrate 1 to form the wiring 2. One side of the first main surface 1a of the first substrate 1 and the wiring 2 is separated by a release film 5, such as a fluorine-based resin, while the other side of the first main surface 1a of the first substrate 1 and the wiring 2 are adhered. Note that, since the wiring 2 is prone to breakage, the first surface 2a of the wiring 2 may be reinforced with Kapton tape, a coating agent, or the like. As shown in Figure 4B, the release film 5 is removed, and the first substrate 1 and the wiring 2 are cut into strips with a width W of 10 mm in the Y direction. As shown in Figure 4C, clamps 6 are attached to a portion of the separated region. A tensile force F2 is applied to the clamps 6 in directions away from each other, i.e., directions 180° apart, to peel them off. A force gauge is used to measure the peel strength. Note that to measure the peel strength between the first substrate 1 and the protective layer 3, the first substrate 1 and the protective layer 3 are used instead of the first substrate 1 and the wiring 2, and the same operation as above is performed. To measure the peel strength between the protective layer 3 and the wiring 2, the protective layer 3 and the wiring 2 are used instead of the first substrate 1 and the wiring 2, and the same operation as above is performed.

[0028] Preferably, the protective layer 3 is a sheet layer 31. For example, when the protective layer 3 is formed by applying a conductive material, if the conductive material contains a solvent, at least a portion of the wiring 2 may dissolve, resulting in electrical resistance. In contrast, when the sheet layer 31 is used as the protective layer 3, the wiring 2 does not dissolve, and electrical resistance is unlikely to occur. Furthermore, the peel strength between the wiring 2 and the first substrate 1 is not reduced. The sheet layer 31 is preferably formed in a vacuum state to prevent air bubbles from being trapped between the wiring 2 and the sheet layer 31. At this time, it is preferable to bond the wiring 2 and the sheet layer 31 while applying pressure and temperature. The thickness of the sheet layer 31 is preferably 1 μm or more and 100 μm or less, more preferably 10 μm or more and 50 μm or less.

[0029] Preferably, the protective layer 3 covers a portion of the first main surface 1a of the first substrate 1. For example, as shown in FIG. 1 , the first main surface 1a of the first substrate 1 has one exposed end portion S3 parallel to the direction in which the wiring 2 extends, a contact portion in contact with the exposed end portion S3 and the protective layer 3 and the wiring 2, and the other exposed end portion S3 in contact with the contact portion. The exposed end portion S3 is an end portion of the first main surface 1a parallel to the direction in which the wiring 2 extends. When an external force F1 is applied to the stretchable device, the first substrate 1 can stretch significantly even at the exposed end portion S3, which is the exposed portion of the first substrate 1, and can absorb the external force F1. This prevents stress from concentrating on the wiring 2.

[0030] Preferably, the peel strength between the protective layer 3 and the wiring 2 is greater than the peel strength between the protective layer 3 and the first substrate 1. With the above configuration, when an external force F1 is applied to the first substrate 1, the protective layer 3 peels off from the first substrate 1 before the protective layer 3 peels off from the wiring 2. Because the wiring 2 and the protective layer 3 are in close contact with each other, no gap is created between the wiring 2 and the protective layer 3, and stress concentration on the wiring 2 can be reduced.

[0031] The peel strength between the wiring 2 and the first substrate 1 may be greater than the peel strength between the wiring 2 and the protective layer 3. In this case, peeling of the wiring 2 from the first substrate 1 due to the tension acting between the portions S1 can be suppressed.

[0032] The peel strength between the wiring 2 and the protective layer 3 may be greater than the peel strength between the wiring 2 and the first substrate 1. In this case, when an external force is applied in a direction perpendicular to the direction in which the external force F1 is applied, i.e., in the vertical direction in FIG. 3 , the applied external force can assist the extension of the wiring 2. As a result, the wiring 2 expands and contracts uniformly, and peeling of the wiring 2 from the first substrate 1 can be suppressed.

[0033] (Manufacturing Method) A method for manufacturing a stretchable device will be described. For example, SBS is prepared as the first substrate 1. A conductive material containing a mixture of silver and resin is applied to the first main surface 1a of the first substrate 1. Examples of the application method include screen printing, gravure printing, and inkjet printing. The conductive material is thermally cured to obtain a predetermined resistance value, thereby forming the wiring 2. The wiring 2 is cured by heating at a temperature of 80°C or higher for 30 minutes or more, for example. After the wiring 2 is provided, a protective layer 3 is provided so as to cover the first main surface 1a of the first substrate 1 and the wiring 2.

[0034] Second Embodiment The structure of a stretchable device 100A according to a second embodiment will be described with reference to Fig. 5. Fig. 5 is an XY cross-sectional view of the stretchable device 100A. The second embodiment differs from the first embodiment in the shape of the protective layer.

[0035] As shown in FIG. 5 , in a cross section perpendicular to the direction in which the wiring 2 extends, the protective layer 3A has a lower portion 3b on the first substrate 1 side, an upper portion 3a on the opposite side from the first substrate 1, and convex curved surfaces 3c on both sides in the width direction connecting the lower portion 3b and the upper portion 3a, where the width of the lower portion 3b is greater than the width of the upper portion 3a. By making the width of the lower portion 3b greater than the width of the upper portion 3a, the volume of the protective layer 3 is reduced, reducing costs and enabling the stretchable device 100A to be made more compact. Furthermore, by having the convex curved portion 3c, there are no corners on the upper portion 3a side of the protective layer 3A. This prevents damage to the protective layer 3A. The lower portion 3b and the upper portion 3a may be connected by a flat portion instead of the convex curved portion 3c. The width of the lower portion 3b in this specification is the sum of the width of the portion of the protective layer 3 that contacts the first substrate 1 and the width of the portion of the wiring 2 that contacts the first substrate 1, as shown in FIG. 5 .

[0036] Preferably, the protective layer 3A is formed by applying a conductive material. The thickness of the protective layer 3A is preferably 1 μm to 10,000 μm greater than the thickness of the wiring 2. The thickness of the protective layer 3A is preferably 1 μm to 100 μm, more preferably 10 μm to 50 μm.

[0037] [Third Embodiment] The structure of a stretchable device 100B according to a third embodiment will be described with reference to Fig. 6. Fig. 6 is a cross-sectional view of the stretchable device 100B. The third embodiment differs from the first embodiment in the configuration of the protective layer.

[0038] As shown in FIG. 6 , the protective layer 3B includes a sheet layer 31 and an adhesive layer 32. The adhesive layer 32 is located between the sheet layer 31 and the wiring 2, and between the sheet layer 31 and the first main surface 1a of the first substrate 1. This configuration improves adhesion between the protective layer 3 and the first substrate 1 and between the protective layer 3 and the wiring 2. Furthermore, when a conductive material is used to form the protective layer 3B, if the conductive material contains a solvent, at least a portion of the wiring 2 may dissolve, resulting in electrical resistance. In contrast, the sheet layer 31 and the adhesive layer 32 prevent the wiring 2 from dissolving, resulting in no electrical resistance. Because the wiring 2 is not dissolved, the peel strength between the wiring 2 and the protective layer 3 is not reduced. Examples of the adhesive layer 32 include an acrylic adhesive, a silicone adhesive, and a urethane adhesive. Specifically, an acrylic adhesive may be used.

[0039] [Fourth Embodiment] The structure of a stretchable device 100C according to a fourth embodiment will be described with reference to Fig. 7 and Fig. 8. Fig. 7 is a top view of the stretchable device 100C. Fig. 8 is a cross-sectional view of the stretchable device 100C taken along line VIII-VIII in Fig. 7. The fourth embodiment differs from the first embodiment in the overlapping relationship between the protective layer and the first base material.

[0040] 7 and 8 , the protective layer 3C covers the entire first main surface 1 a of the first base material 1. That is, the first main surface 1 a has no exposed edge portions. By having the above-described configuration, it is possible to suppress localized stress concentration in the first base material 1.

[0041] Fifth Embodiment The structure of a stretchable device 100D according to a fifth embodiment will be described with reference to Fig. 9. Fig. 9 is a cross-sectional view of the stretchable device 100D. The fifth embodiment differs from the fourth embodiment in the configuration of the protective layer.

[0042] As shown in Fig. 9, the material of the protective layer 3D is the same as the material of the first substrate 1. Specifically, wiring 2 is provided on one first substrate 1, and then the other first substrate 1 is provided so as to cover the wiring 2, and the other first substrate 1 is provided so as to entirely cover the one first substrate 1 and the wiring 2. With the above configuration, the stretchability of the stretchable device 100D can be improved. Furthermore, the types of materials used can be reduced, resulting in cost reduction.

[0043] Sixth Embodiment The structure of a stretchable device 100E according to a sixth embodiment will be described with reference to Fig. 10 and Fig. 11. Fig. 10 is a top view of the stretchable device 100E. Fig. 11 is a cross-sectional view of the stretchable device 100E taken along line XI-XI in Fig. 10. The sixth embodiment differs from the first embodiment in the number of protective layers, and an exposed surface of the first main surface exists between two wirings.

[0044] As shown in Figures 10 and 11, the protective layer 3E covers the entire wiring 2. Specifically, two wirings 2 and two protective layers 3E are located on the first main surface 1a of the first substrate 1, with one protective layer 3E covering one wiring 2 and the other protective layer 3E covering the other wiring 2. One protective layer 3E is spaced apart from the other protective layer 3E. The first main surface 1a has, in the X-axis direction, an exposed end S13, a portion S12 in contact with one protective layer 3E and adjacent to the exposed end S13, an exposed portion S11 adjacent to the portion S12, a portion S12 in contact with the other protective layer 3E and adjacent to the exposed portion S11, and an exposed end S13 adjacent to the portion S12, in this order. In this embodiment, the protective layer 3E is not disposed on the portion S12, thereby ensuring an area that is not constrained by the protective layer 3E, and more effectively mitigating the effects of external forces.

[0045] Furthermore, in this embodiment, the peel strength of portions S15 and S16 of portion S12, where the first substrate 1 and the protective layer 3E are in direct contact, is relatively lower than the peel strength of portion S14, where the first substrate 1 and the wiring 2 are in direct contact. Therefore, in portion S12, portions S15 and S16 are more likely to peel from the first substrate 1 than portion S14. Furthermore, because portion S15 is located between the wiring 2, portion S15 is more likely to peel from the first substrate 1 than portion S16. For this reason, when the stretchable device 100E stretches and contracts, portion S15 may peel from the first substrate 1. That is, in this embodiment, the peel strength can be controlled by having portion S15.

[0046] In this configuration, the gap caused by expansion and contraction (the gap caused by peeling of the portion S15 from the first substrate 1) may or may not be integrated with the exposed portion S11. Specifically, the exposed portion S11 and the portion S15 are integrated when the entire portion S15 is peeled off, or when the region of the portion S15 on the exposed portion S11 side is peeled off. The exposed portion S11 and the portion S11 are not integrated when a region of the portion S15 other than the exposed portion S11 side is peeled off. For example, this may be the case when the region of the portion S15 on the portion S14 side is peeled off.

[0047] The present disclosure is not limited to the above-described embodiments, and design modifications are possible within the scope of the present disclosure. For example, the features of the first to sixth embodiments may be combined in various ways.

[0048] The present disclosure includes the following aspects. <1> A stretchable device comprising: a stretchable first substrate having a first main surface; wiring provided on the first main surface of the first substrate; and a protective layer covering at least a portion of the first main surface of the first substrate and at least a portion of the wiring, wherein the peel strength between the wiring and the first substrate is greater than the peel strength between the protective layer and the first substrate. <2> The stretchable device according to <1>, wherein the protective layer has, in a cross section perpendicular to the extension direction of the wiring, a lower portion on the first substrate side, an upper portion on an opposite side to the first substrate, and convex curved surfaces on both sides in the width direction connecting the lower portion and the upper portion, and the width of the lower portion is greater than the width of the upper portion. <3> The stretchable device according to <1>, wherein the protective layer has a sheet layer and an adhesive layer, and the adhesive layer is located between the wiring and the sheet layer and between the first main surface of the first substrate and the sheet layer. <4> The stretchable device according to <1>, wherein the protective layer is a sheet layer and is in contact with the first main surface of the first base material on which the wiring is provided. <5> The stretchable device according to any one of <1> to <4>, wherein the protective layer covers the entire first main surface of the first base material. <6> The stretchable device according to any one of <1> to <4>, wherein the protective layer covers a part of the first main surface of the first base material. <7> The stretchable device according to any one of <1> to <6>, wherein the material of the protective layer is the same as the material of the first base material. <8> The stretchable device according to any one of <1> to <7>, wherein the protective layer covers the entire wiring. <9> The stretchable device according to any one of <1> to <8>, wherein a peel strength between the protective layer and the wiring is greater than a peel strength between the protective layer and the first base material.

[0049] This application claims priority based on Japanese Patent Application No. 2023-092419, filed on June 5, 2023, the entire contents of which are incorporated herein by reference.

[0050] 100, 100A, 100B, 100C, 100D, 100E Stretchable base 1 1st base material 1a 1st main surface 2 Wiring 3, 3A, 3B, 3C, 3D, 3E Protective layer 3a Upper part 3b Lower part 3c Convex part 31 Shield layer 32 Adhesive layer

Claims

1. a stretchable first substrate having a first major surface; wiring provided on the first main surface of the first base material; a protective layer covering at least a portion of the first main surface of the first base material and at least a portion of the wiring; Equipped with a peel strength between the wiring and the first base material is greater than a peel strength between the protective layer and the first base material; Stretchable devices.

2. the protective layer has, in a cross section perpendicular to the extending direction of the wiring, a lower portion on the first substrate side, an upper portion on the opposite side to the first substrate, and convex curved surfaces on both sides in a width direction connecting the lower portion and the upper portion; The width of the lower portion is greater than the width of the upper portion.

10. The stretchable device of claim 1.

3. the protective layer has a sheet layer and an adhesive layer, the adhesive layer is located between the wiring and the sheet layer, and between the first main surface of the first base material and the sheet layer; 10. The stretchable device of claim 1.

4. the protective layer is a sheet layer and is in contact with the first main surface of the first base material on which the wiring is provided.

10. The stretchable device of claim 1.

5. The stretchable device according to claim 1 , wherein the protective layer covers the entire first main surface of the first substrate.

6. The stretchable device according to claim 1 , wherein the protective layer covers a portion of the first main surface of the first substrate.

7. The material of the protective layer is the same as the material of the first substrate.

5. The stretchable device of claim 1 .

8. The stretchable device according to claim 1 , wherein the protective layer covers the entire wiring.

9. The stretchable device according to claim 1 , wherein a peel strength between the protective layer and the wiring is greater than a peel strength between the protective layer and the first substrate.