Stretchable device

Abstract

One embodiment of the present invention provides a stretchable device including: a stretchable base material; a plurality of flexible first conductive parts provided on the stretchable base material and separated from each other; and stretchable second conductive parts contacting a portion of the first conductive parts.

Description

stretchable devices

[0001] The present invention relates to a stretchable device.

[0002] Stretchable devices having stretchable wiring provided on a stretchable substrate have been known for some time, and these stretchable devices can be attached to a living body when used (see Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2018-164015

[0004] Here, there are cases where two stretchable wirings with different stretchability, i.e., stretchable conductive parts, are provided on a stretchable substrate. In this case, if a material containing silver or the like is used as the material for both of the two conductive parts, the resistivity of the conductive part as a whole may become high.

[0005] Therefore, an object of the present invention is to provide a stretchable device having a conductive part that can preferably ensure a predetermined stretchability and reduce resistance.

[0006] In order to achieve the above object, one embodiment of the present invention provides a stretchable device including: a stretchable substrate; a plurality of first conductive portions that are spaced apart from each other and are flexible and are provided on the stretchable substrate; and a second conductive portion that is in contact with a portion of the first conductive portion and is stretchable.

[0007] According to a stretchable device according to one embodiment of the present invention, the conductive parts of the components thereof can preferably ensure a predetermined stretchability and reduce resistance.

[0008] FIG. 1 is a plan view schematically showing a stretchable device according to a first embodiment of the present invention. FIG. 2A is a plan view schematically showing a first-layer stretchable device according to a second embodiment of the present invention. FIG. 2B is a plan view schematically showing a second-layer stretchable device according to the second embodiment of the present invention. FIG. 2C is a plan view schematically showing stacked stretchable devices according to the second embodiment of the present invention. FIG. 3 is a plan view schematically showing a stretchable device according to a third embodiment of the present invention. FIG. 4 is a plan view schematically showing a stretchable device according to a fourth embodiment of the present invention. FIG. 5 is a plan view schematically showing a stretchable device according to a fifth embodiment of the present invention. FIG. 6 is a plan view schematically showing a conventional stretchable device in which the entire first conductive part is covered with the second conductive part. FIG. 7 is a plan view schematically showing a stretchable device comparable to the stretchable device of the first embodiment. FIG. 8A is a plan view schematically showing a first-layer stretchable device comparable to the stretchable device of the second embodiment. FIG. 8B is a plan view schematically showing a second-layer stretchable device comparable to the stretchable device of the second embodiment. Fig. 8C is a plan view schematically showing a stacked stretchable device comparable to the stretchable device of the second embodiment. Fig. 9 is a plan view schematically showing a stretchable device comparable to the stretchable device of the third embodiment.

[0009] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In each embodiment, differences from those described previously will be mainly described. In particular, similar effects resulting from similar configurations will not be mentioned in each embodiment. Among the components in the following embodiments, components that are not recited in independent claims will be described as optional components. The size and size ratio of components shown in the drawings are not necessarily strict. Furthermore, in each figure, substantially identical components are assigned the same reference numerals, and duplicated descriptions may be omitted or simplified.

[0010] First Embodiment Hereinafter, the configuration of a stretchable device 100 according to a first embodiment will be described with reference to FIG.

[0011] FIG. 1 is a plan view schematically showing a stretchable device according to a first embodiment of the present invention.

[0012] The stretchable device 100 according to the first embodiment of the present invention includes a stretchable substrate 10 and different types of conductive portions (first conductive portion 20 and second conductive portion 30) provided on the stretchable substrate 10. The first conductive portion 20 is flexible and provided in plurality, spaced apart from one another. The second conductive portion 30 contacts a portion of the first conductive portion 20 and is flexible and stretchable. Note that in this embodiment, the first conductive portion 20 may have relatively smaller stretchability than the second conductive portion 30. In other words, the second conductive portion 30 may have relatively greater stretchability than the first conductive portion 20.

[0013] The term "above" used in this specification includes a state of being above an element at a distance, i.e., being above an element via another object, a state of being above an element with a gap, and a state of being directly above an element in contact with the element. In addition, in the drawings, at the partial contact point between the first conductive portion 20 and the second conductive portion 30, a part of the first conductive portion 20 that may be located in the underlying layer is indicated by a dotted line.

[0014] The stretchable substrate 10 is a sheet-like or film-like stretchable substrate, and is made of, for example, a stretchable resin material, such as thermoplastic polyurethane (TPU), polyethylene (PE), polystyrene (PS), or polyethylene terephthalate (PET).

[0015] The thickness of the stretchable substrate 10 is not particularly limited, but is preferably 100 μm or less, more preferably 50 μm or less, from the viewpoint of not inhibiting the expansion and contraction of the surface of the living body when attached to the living body. Furthermore, the thickness of the stretchable substrate 10 is preferably 20 μm or more from the viewpoint of ensuring a predetermined strength.

[0016] The first conductive part 20 may be a metal foil. For example, copper may be used as the metal foil. In this embodiment, the first conductive part 20 may have a block shape, such as a rectangular shape, in a plan view. The second conductive part 30 may include a resin and a particulate conductive material dispersed in the resin. For example, the second conductive part 30 may be a mixture of a metal powder such as Ag or a non-metal powder such as a carbon-based conductive material, as a conductive material, and an elastomer resin such as a silicone resin. The average particle size of the conductive material is not particularly limited, but is preferably 0.01 μm or more and 10 μm or less. Furthermore, the conductive material is preferably spherical in shape.

[0017] The thickness of the first conductive part 20 and the second conductive part 30 is not particularly limited, but is preferably 100 μm or less, and more preferably 50 μm or less. The thickness of these conductive parts is preferably 0.1 μm or more.

[0018] According to the above configuration, compared to when two conductive parts with different elasticity are provided on a stretchable substrate, one of the two conductive parts, second conductive part 30, has elasticity, while first conductive part 20 does not have elasticity. Therefore, compared to when both of the two conductive parts contain a silver material or the like as a component, the resistivity of the conductive part as a whole can be made lower, and low resistance can be achieved.

[0019] Furthermore, as shown in FIG. 6 , conventional stretchable devices may be configured such that a second conductive portion 30″ (corresponding to the second conductive portion 30 described above) continuously covers a substrate 10″ (corresponding to the stretchable substrate 10 described above) and a first conductive portion 20″ (corresponding to the first conductive portion 20 described above). In this case, the entire first conductive portion 20″ and the second conductive portion 30″ may overlap each other in plan view. In such a configuration, there is a risk that the stretchability of the second conductive portion 30″ may be impaired due to a difference in the degree (magnitude) of stretchability between the second conductive portion 30″ and the first conductive portion 20″.

[0020] In contrast, in the present embodiment, due to contact between a portion of the first conductive portion 20 and the second conductive portion 30, the first conductive portion 20, specifically a portion of the first conductive portion 20, may be exposed without the entire first conductive portion 20 and the second conductive portion 30 overlapping in a planar view. In this case, the second conductive portion 30 may not continuously cover the substrate 10 and the first conductive portion 20, but may mainly cover the substrate 10 located between the first conductive portions 20 that are spaced apart from each other. In other words, the second conductive portion 30 may have a form in which, in a planar view, the stretchable substrate 10 and the first conductive portion 20 are discontinuously covered. In this specification, "partial exposure of the first conductive portion 20" means exposure from the second conductive portion 30, and other components such as an insulating layer may be disposed on the first conductive portion 20.

[0021] In this configuration, the second conductive part 30 can be efficiently positioned at a location where stretchability is desired, and as a result, it is possible to prevent the stretchability of the second conductive part 30 from being hindered due to differences in the degree of stretchability between the second conductive part 30 and the first conductive part 20. This makes it possible to preferably ensure the predetermined stretchability of the second conductive part 30.

[0022] As described above, according to the stretchable device 100 of the first embodiment, it is possible to preferably ensure a predetermined stretchability and reduce resistance by using the two conductive parts (first conductive part 20, second conductive part 30) of its components.

[0023] The configuration of the stretchable device 100 shown in Fig. 1 will be specifically described below. As shown in Fig. 1, the first conductive parts 20 are arranged at predetermined intervals in the vertical and horizontal directions, and the second conductive parts 30 or the stretchable substrate 10 are arranged so as to connect the adjacent first conductive parts 20 in a plan view.

[0024] In this case, the stretchable region 50 including at least one of the stretchable substrate 10 and the second conductive part 30 extends continuously in a direction intersecting the stretch direction of these stretchable members. In this specification, the "stretch direction" refers to the main stretch direction of the stretchable member.

[0025] The stretchable region 50 shown in FIG. 1 includes, for example, a second conductive section 30, a stretchable substrate 10, and a second conductive section 30 that are continuous with one another, and extends continuously in the longitudinal direction perpendicular to the stretching direction indicated by the arrow.

[0026] With this configuration, compared to when at least one of the stretchable substrate 10' and the second conductive portion 30' and the first conductive portion 20' are arranged in parallel (see FIG. 7 ), the stretchable region 50 includes a non-overlapping region where the first conductive portion 20 and the second conductive portion 30 do not overlap in a planar view, and preferably the majority of the stretchable region 50 can be the non-overlapping region. For example, the proportion of the non-overlapping region in the stretchable region 50 can be approximately 90% or more. This makes it less likely that the stretching and contracting motion of the stretchable member will be hindered. Note that the above description is based on a configuration in which the stretchable region can extend continuously in the X direction, but this is not limited thereto. The stretchable region can also be configured to extend continuously in the Y direction, and the stretching and contracting motion of the stretchable member will also be less likely to be hindered.

[0027] Furthermore, because the first conductive part 20 and the second conductive part 30 provided on the stretchable substrate 10 are in partial contact with each other, steps are unlikely to occur across these conductive parts as a whole, which can reduce discomfort when applied to the human body.

[0028] Furthermore, the stretchable device 100 of this embodiment can further include electronic components, for example, by forming component mounting lands on the first conductive part 20. The first conductive part 20 is made of metal foil and has a relatively lower resistance than the stretchable second conductive part 30, making it possible to suitably mount electronic components that may experience a large current density around the terminals. Examples of electronic components include sensors, coils, oscillators, etc.

[0029] The following mainly describes the characteristic configuration of each embodiment. In order to avoid duplication of content, descriptions of configurations that are the same or substantially the same as those of the embodiments already described before the description of each embodiment will be omitted or omitted.

[0030] [Second embodiment] The configuration of a stretchable device according to the second embodiment will be described below with reference to Figures 2A to 2C. The second embodiment differs from the first embodiment (see Figure 1) in that a plurality of stretchable devices are stacked, and in the stacking direction, the stretchable region in the Xth layer (X: natural number, the same applies below) overlaps with the stretchable region in the X+1th layer.

[0031] Fig. 2A is a plan view schematically showing a first layer stretchable device according to a second embodiment of the present invention, Fig. 2B is a plan view schematically showing a second layer stretchable device according to the second embodiment of the present invention, and Fig. 2C is a plan view schematically showing stacked stretchable devices according to the second embodiment of the present invention.

[0032] 2A to 2C, the stacked stretchable device of Fig. 2C (which may also be referred to as a multilayer stretchable device) is obtained by stacking the stretchable device shown in Fig. 2A and the stretchable device shown in Fig. 2B along the stacking direction. In Fig. 2A and Fig. 2B, the case of X = 1 described above is taken as an example, but is not limited to this.

[0033] Specifically, in Fig. 2A , in the Y direction, the stretchable region 50A is composed of a stretchable substrate 10A and a second conductive part 30A that are continuous with each other, and extends continuously in the longitudinal direction perpendicular to the stretch direction indicated by the arrow. In the X direction, the stretchable region 50A may be composed of a stretchable substrate 10A that extends in one direction. Meanwhile, in Fig. 2B , in the Y direction, the stretchable region 50A is composed of a stretchable substrate 10B that extends in one direction, and extends continuously in the longitudinal direction perpendicular to the stretch direction indicated by the arrow.

[0034] In this case, in this embodiment, as shown in Figure 2C, in a planar view, when the stretchable device 100A and the stretchable device 100B are stacked, the above-mentioned stretchable region 50A in the first layer and the above-mentioned stretchable region 50B in the second layer are arranged to overlap each other, and a stretchable stacked region 50C can be formed.

[0035] That is, the elastic laminated region 50C composed of the elastic region 50A and the elastic region 50B extends continuously as a whole in a laminated direction that intersects with the elastic direction of the elastic member (elastic substrate and / or second conductive part).

[0036] With this configuration, compared to when the stretchable region 50A' in the first layer and the stretchable region 50B' in the second layer are positioned offset in a planar view (see Figures 8A to 8C), the majority of the stretchable laminated region 50X is non-overlapping in that the first conductive part 20A and the second conductive part 30A do not overlap, so the stretching and contracting action of the stretchable member is less likely to be hindered.

[0037] 2A and 2B , in comparison with the case where a single stretchable region extends continuously in one direction, in this embodiment, a plurality of stretchable regions 50A, 50B are provided, and the plurality of stretchable regions 50A, 50B are arranged in parallel and spaced apart from each other in a plan view. In one example, the plurality of stretchable regions can be arranged in parallel with the first conductive parts 20A, 20B sandwiched between them.

[0038] 2A , in a plan view, the stretchable regions 50A and the first conductive parts 20A may be alternately arranged along the stretching direction indicated by the arrows. Furthermore, for example, the stretchable regions 50A extending in the X direction and the stretchable regions 50A extending in the Y direction may intersect with each other, and the multiple stretchable regions 50A may form a lattice pattern as a whole.

[0039] By adopting the above-described configuration, it is possible to increase the amount of stretch of the stretchable device in a specified direction (e.g., the X direction) compared to when a single stretchable region extends continuously in one direction, and it is also possible to increase the amount of stretch in a direction different from the specified direction (e.g., the Y direction).

[0040] [Third Embodiment] The configuration of a stretchable device according to a third embodiment will be described below with reference to Fig. 3. The third embodiment differs from the first embodiment (see Fig. 1) in that the second conductive portion has a meandering shape in plan view.

[0041] FIG. 3 is a plan view schematically showing a stretchable device according to a third embodiment of the present invention.

[0042] This embodiment is characterized in that the second conductive portion 30C has a meandering shape in plan view. Here, the resistance R of the second conductive portion is expressed by the following equation 1, where ρ is the resistivity, W is the width, t is the thickness, and l is the length.

[0043] [Formula 1] R=ρl / (W×t)

[0044] 9, the width w is not sufficiently large, which can increase the resistance R. Furthermore, when the second conductive portion 30C' is stretched in the direction of the arrow shown in FIG. 9, the resistance of the second conductive portion 30C' increases as it is stretched, which can increase the resistance of the entire conductive portion.

[0045] In contrast, in this embodiment, the second conductive portion 30C has a meandering shape in plan view, which allows the overall total width to be increased, thereby suppressing an increase in resistance compared to a configuration in which the second conductive portion 30C′ extends in one direction between the first conductive portions 20C′ (see FIG. 9 ).

[0046] Furthermore, when one of the adjacent first conductive portions 20C, 21C, moves to the left and the other, 22C, moves to the right in plan view, regions a, e, and f in the second conductive portion 30C located between them expand, while regions c and h may contract, resulting in both regions of increased width and regions of decreased width coexisting in the second conductive portion. This can suppress an increase in the resistance of the second conductive portion 30 as a whole.

[0047] Furthermore, when one of the adjacent first conductive portions 20C, 21C, moves upward and the other, 22C, moves downward, regions b and d in the second conductive portion 30C may expand while regions i and g may contract, so that regions in the second conductive portion 30C may have both increased widths and decreased widths. This can suppress an increase in the resistance of the second conductive portion 30 as a whole.

[0048] [Fourth embodiment] The configuration of a stretchable device according to a fourth embodiment will be described below with reference to Fig. 4. The fourth embodiment differs from the first embodiment (see Fig. 1) in that it further includes meandering wiring that connects a plurality of first conductive parts together in a planar view.

[0049] FIG. 4 is a plan view schematically showing a stretchable device according to a fourth embodiment of the present invention.

[0050] The fourth embodiment differs from the first embodiment (see FIG. 1 ) in that it further includes meandering wiring that connects a plurality of first conductive parts together in a plan view. This configuration not only achieves the effects of the first embodiment, but also improves the connectivity between adjacent first conductive parts 20D.

[0051] [Fifth Embodiment] The configuration of a stretchable device according to a fifth embodiment will be described below with reference to Fig. 5. The fifth embodiment differs from the first embodiment (see Fig. 1) in that a plurality of stretchable devices are arranged in the stacking direction, and the first conductive part has a coil shape in plan view.

[0052] FIG. 5 is a plan view schematically showing a stretchable device according to a fifth embodiment of the present invention.

[0053] This embodiment is characterized in that a plurality of stretchable devices are arranged in the stacking direction, and the first conductive part 20E has a coil shape in plan view. In this case, as shown in Fig. 5 , one first conductive part 21E and the other first conductive part 22E that are adjacent and spaced apart from each other are connected via a stretchable second conductive part 30E.

[0054] In this embodiment, specifically, in the stacking direction, for example, the stretchable region 50E in the first layer and the stretchable region 50E in the second layer can be arranged to overlap each other, thereby forming a stretchable laminated region.

[0055] That is, the stretchable laminate region as a whole extends continuously through the connection vias in a lamination direction that intersects with the stretchable direction of the stretchable member (stretchable substrate and / or second conductive portion). With this configuration, the first conductive portion 20E is not present within the stretchable laminate region in a plan view, and therefore the stretchable action of the stretchable member is less likely to be hindered.

[0056] It should be noted that each embodiment and modification is merely an example, and the present invention is not limited to each embodiment and modification. Also, each drawing is an example of components, and does not limit the shape. Furthermore, partial substitution or combination of the configurations shown in different embodiments and modifications is possible.

[0057] Note that aspects of a stretchable device according to an embodiment of the present invention are as follows. <1> A stretchable device comprising: a stretchable substrate; a plurality of first conductive parts that are spaced apart from each other and are flexible, and a second conductive part that is in contact with a part of the first conductive parts and has stretchability, provided on the stretchable substrate. <2> The stretchable device according to <1>, in which a part of the first conductive part is exposed in a planar view. <3> The stretchable device according to <1> or <2>, in which the second conductive part is in a discontinuous form. <4> The stretchable device according to any of <1> to <3>, in which a stretchable region comprising at least one of the stretchable substrate and the second conductive part extends so as to be continuous in an intersecting direction intersecting with a stretching direction. <5> The stretchable device according to <4>, in which, in a planar view, the stretchable region includes a non-overlapping region where the first conductive part and the second conductive part do not overlap. <6> The stretchable device according to <4> or <5>, in which the intersecting direction is a direction perpendicular to the stretching direction. <7> The stretchable device according to any one of <4> to <6>, wherein the intersecting direction is a longitudinal extension direction of the stretchable region in a planar view. <8> The stretchable device according to any one of <4> to <7>, wherein there is a plurality of the stretchable regions, and the plurality of stretchable regions are arranged in parallel and spaced apart. <9> The stretchable device according to any one of <4> to <8>, wherein the stretchable regions and the first conductive parts are arranged alternately along the stretching direction in a planar view. <10> The stretchable device according to any one of <4> to <9>, wherein there is a plurality of the stretchable regions, and the plurality of stretchable regions intersect with each other. <11> The stretchable device according to any one of <4> to <10>, wherein there is a plurality of the stretchable regions, and the plurality of stretchable regions form a lattice pattern. <12> The stretchable device according to any one of <4> to <11>, wherein a plurality of the stretchable regions are arranged in a stacking direction, and the intersecting direction is the stacking direction. <13> The stretchable device according to <12>, wherein the stretchable region in the Xth layer (X: natural number, the same applies hereinafter) and the stretchable region in the X+1th layer overlap in the stacking direction. <14> The stretchable device according to any one of <1> to <13>, wherein the second conductive part has a meandering shape in plan view.<15> The stretchable device according to any one of <1> to <14>, further comprising meandering wiring connecting the plurality of first conductive parts to each other. <16> The stretchable device according to any one of <1> to <5>, wherein a plurality of the first conductive parts are arranged in the stacking direction, and the first conductive parts are in the form of a coil in plan view. <17> The stretchable device according to any one of <1> to <16>, wherein the first conductive part has relatively smaller stretchability than the second conductive part. <18> The stretchable device according to any one of <1> to <17>, wherein the first conductive part is a metal foil. <19> The stretchable device according to <18>, wherein a constituent material of the first conductive part is copper. <20> The stretchable device according to any one of <1> to <19>, wherein a constituent material of the second conductive part includes a resin and a conductive member, and the conductive member is at least one selected from silver and carbon-based materials.

[0058] 100, 100A to 100E, 100', 100A', 100B', 100C', 100"... Stretchable device 100X, 100X'... Stretchable device in laminated form (corresponding to a multilayer stretchable device) 10, 10A to 10D, 10', 10A', 10B', 10C', 10"... Stretchable substrate 20, 20A to 20E, 21C, 22C, 21E, 22E, 20', 20A', 20B', 20C', 20"... First conductive part 30, 30A to 30E, 30', 30A', 30B', 30C', 30"... Second conductive part 40", 50"... Electronic component 50, 50A, 50B, 50A', 50B'... Stretchable region 50X...stretchable laminated area

Claims

1. A stretchable substrate, a plurality of first conductive parts provided on the stretchable substrate, spaced apart from each other and having flexibility, and a second conductive part in contact with a part of the first conductive part and having stretchability The stretchable device includes a first region where the second conductive part does not overlap with the plurality of first conductive parts when viewed from the thickness direction of the stretchable substrate, and at least a part of the first region forms a meandering shape, and the second conductive part forming the meandering shape is continuous.

2. A stretchable substrate, a plurality of first conductive parts provided on the stretchable substrate, spaced apart from each other and having flexibility, and a second conductive part in contact with a part of the first conductive part and having stretchability The stretchable device includes a plurality of layers arranged in the stacking direction, and the first conductive part forms a coil shape in plan view.

3. The stretchable device according to claim 1 or 2, wherein a stretchable region including at least one of the stretchable substrate and the second conductive part extends continuously in a crossing direction that intersects the stretching direction.

4. The stretchable device according to claim 3, wherein a plurality of layers are arranged in the stacking direction, and the crossing direction is the stacking direction.

5. The stretchable device according to claim 3, wherein in the stacking direction, the stretchable region in the Xth layer (X: natural number, the same hereinafter) overlaps with the stretchable region in the (X + 1)th layer.

6. The stretchable device according to claim 1 or 2, wherein the first conductive part has relatively less stretchability than the second conductive part.

7. The stretchable device according to claim 1 or 2, wherein the first conductive part is a metal foil.

8. The stretchable device according to claim 7, wherein the constituent material of the first conductive part is copper.

9. The stretchable device according to claim 1 or 2, wherein the constituent material of the second conductive part includes a resin and a conductive member, and the conductive member is at least one selected from silver and carbon-based materials.