JP7622704B2 - Stretchable Devices - Google Patents

Description

The present invention relates to a stretchable device.

Stretchable devices in which stretchable wiring is mounted on a stretchable substrate have been known for some time. These stretchable devices can be worn on the human body.

The stretchable device includes a stretchable substrate, a first stretchable wiring provided on the stretchable substrate, a second stretchable wiring arranged on the first stretchable wiring, an insulating layer arranged in the wiring overlapping portion between the first stretchable wiring and the second stretchable wiring, and an adhesive layer for mounting (see Patent Document 1).

JP 2021-64676 A

However, depending on the properties of the adhesive layer or bonding layer, there is a risk that the thickness of the insulating layer located at the overlapping portion between the two stretchable wirings may become thinner during stretching. Such a reduction in the thickness of the insulating layer leads to a decrease in the IR (insulation resistance) between the two wirings. As a result, there is a risk of a decrease in the device's functions such as sensing and signal communication, as well as the occurrence of short circuits due to ion migration and wiring contact.

The present invention aims to provide a stretchable device that can suppress a decrease in IR (insulation resistance) between wiring.

In order to achieve the above object, in one embodiment of the present invention,
A stretchable device is provided, comprising: a stretchable substrate; a first stretchable wiring and a second stretchable wiring provided on the stretchable substrate and partially overlapping each other in a thickness direction of the stretchable substrate; an insulating layer disposed in a wiring overlap portion between the first stretchable wiring and the second stretchable wiring; and a first adhesive layer overlapping at least a portion of the insulating layer in the thickness direction, wherein the first adhesive layer has a stretchability relatively smaller than that of the insulating layer.

The stretchable device according to one embodiment of the present invention can suppress a decrease in IR (insulation resistance) between wiring.

FIG. 1 is a plan view illustrating a stretchable device according to a first embodiment of the present invention. FIG. 2 is a partially enlarged schematic plan view of the stretchable device according to the first embodiment of the present invention. FIG. 3 is a partially enlarged schematic cross-sectional view of the stretchable device according to the first embodiment of the present invention taken along line XX in FIG. 2 before stretching. FIG. 4 is a partially enlarged schematic cross-sectional view of the stretchable device according to the first embodiment of the present invention taken along line XX in FIG. 2 during stretching. FIG. 5 is a partially enlarged schematic cross-sectional view of Modification 1 of the stretchable device according to the first embodiment of the present invention (corresponding to the cross-sectional view taken along line XX in FIG. 2). FIG. 6 is a partially enlarged schematic cross-sectional view of Modification 2 of the stretchable device according to the first embodiment of the present invention (corresponding to the cross-sectional view taken along line XX in FIG. 2). FIG. 7 is a partially enlarged schematic cross-sectional view of a stretchable device according to a second embodiment of the present invention (corresponding to the cross-sectional view taken along line XX in FIG. 2). FIG. 8 is a partially enlarged schematic cross-sectional view of Modification 1 of the stretchable device according to the second embodiment of the present invention (corresponding to the cross-sectional view taken along line XX in FIG. 2). FIG. 9 is a partially enlarged schematic cross-sectional view of Modification 2 of the stretchable device according to the second embodiment of the present invention (corresponding to the cross-sectional view taken along line XX in FIG. 2). FIG. 10 is a plan view illustrating a stretchable device according to a third embodiment of the present invention. FIG. 11 is a partially enlarged schematic cross-sectional view of the stretchable device according to the third embodiment of the present invention taken along line YY in FIG. FIG. 12 is a plan view illustrating a stretchable device according to a fourth embodiment of the present invention. FIG. 13 is a partially enlarged schematic cross-sectional view of the stretchable device according to the fourth embodiment of the present invention taken along line Z-Z in FIG. FIG. 14 is a plan view illustrating a stretchable device according to a fifth embodiment of the present invention. FIG. 15 is a partially enlarged schematic cross-sectional view of the stretchable device according to the fifth embodiment of the present invention taken along line segment WW in FIG. FIG. 16 is a partially enlarged schematic cross-sectional view of a conventional stretchable device before stretching. FIG. 17 is a partially enlarged schematic cross-sectional view of a conventional stretchable device during stretching.

Below, the embodiments of the present invention will be described in detail with reference to the drawings. In each embodiment, differences from the previous embodiments will be mainly described. In particular, similar effects due to similar configurations will not be mentioned in each embodiment. Among the components in the following embodiments, components that are not described in an independent claim will be described as optional components. Furthermore, the size and size ratio of the components shown in the drawings are not necessarily strict. Furthermore, in each figure, substantially identical configurations are given the same reference numerals, and duplicated descriptions may be omitted or simplified.

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

Figure 1 is a plan view showing a schematic diagram of a stretchable device according to a first embodiment of the present invention. Figure 2 is a partially enlarged schematic plan view of a stretchable device according to a first embodiment of the present invention. Figure 3 is a partially enlarged schematic cross-sectional view of the stretchable device according to the first embodiment of the present invention taken along line segment X-X in Figure 2 before stretching. Figure 4 is a partially enlarged schematic cross-sectional view of the stretchable device according to the first embodiment of the present invention taken along line segment X-X in Figure 2 during stretching. In addition, in the cross-sectional views in this specification, the thickness direction of the stretchable substrate, which will be described later, is indicated by a double-headed arrow X. Also, Figures 3 and 4 are cross-sectional views taken along line segment X-X in Figure 2, i.e., in the extension direction of the first stretchable wiring.

The stretchable device 100 according to the first embodiment of the present invention comprises a stretchable substrate 10, a first stretchable wiring 20, a second stretchable wiring 40, an insulating layer 30 and a first adhesive layer 50 (see Figures 1 to 4).

The components of the stretchable device 100 will be described in detail below. After that, the characteristic parts of the first embodiment will be described.

(Stretchable substrate 10)
The stretchable substrate 10 is a sheet-like or film-like stretchable substrate, and is made of, for example, a resin material having stretchability. Examples of the resin material of the stretchable substrate 10 include thermoplastic polyurethane (TPU), polyethylene (PE), polystyrene (PS), and polyethylene terephthalate (PET).

The thickness of the stretchable substrate 10 is not particularly limited, but is preferably 100 μm or less, and more preferably 50 μm or less, from the viewpoint of not inhibiting the stretching of the surface of the living body when attached to the living body. In addition, the thickness of the stretchable substrate 1 is preferably 20 μm or more from the viewpoint of ensuring a certain strength.

(First elastic wiring 20/second elastic wiring 40)
The first elastic wiring 20 and the second elastic wiring 40 are provided on the elastic substrate 10, specifically on the main surface thereof, and are mutually separated in the thickness direction X of the elastic substrate 10. It overlaps with the target.

In this specification, "above" includes a state where it is located above an element and separated from it, i.e., above an element via another object, a state where it is located above an element with a gap, and a state where it is located directly above an element and in contact with it.

Therefore, in this specification, "the first elastic wiring 20 and the second elastic wiring 40 arranged on the elastic substrate 10" includes the first and second elastic wiring 20, 40 in contact with the main surface of the elastic substrate 10, and the first and second elastic wiring 20, 40 in a state where they are separated from the main surface via another member (for example, a resin layer described later) without directly contacting the main surface of the elastic substrate 10.

In one example, as shown in FIG. 1, the first elastic wiring 20 and the second elastic wiring 40 form a wiring intersection portion that intersects with each other. For example, the first elastic wiring 20 and the second elastic wiring 40 form a wiring intersection portion that intersects with each other perpendicularly. The first elastic wiring 20 and the second elastic wiring 40 are each electrically connected to the electronic component 200.

The first elastic wiring 20 and the second elastic wiring 40 each contain conductive particles and a resin. For example, each elastic wiring may be a mixture of metal powder such as Ag, Cu, or Ni as conductive particles and an elastomer resin such as a silicone resin. The average particle size of the conductive particles is not particularly limited, but is preferably 0.01 μm or more and 10 μm or less. In addition, the conductive particles are preferably spherical in shape.

The thickness of each elastic wire is not particularly limited, but is preferably 100 μm or less, and more preferably 50 μm or less. The thickness of each elastic wire is preferably 0.01 μm or more. The line width of each elastic wire is not particularly limited, but is preferably 0.1 μm or more, and more preferably 10 mm or less. The shape and number of each elastic wire are not particularly limited.

In addition, from the viewpoint of more reliably preventing short circuits during use of the stretchable device 100, it is preferable that the extension direction of the first stretchable wiring 20 is the longitudinal direction (i.e., the stretching direction) of the stretchable device 100.

(Insulating layer 30)
The insulating layer 30 is a layer disposed to prevent short circuits caused by contact between the elastic wirings. Specifically, the insulating layer 30 is disposed in a wiring overlapping portion 70 between the first elastic wiring 20 and the second elastic wiring 40. From the viewpoint of suitably avoiding contact between the wirings, the width of the insulating layer 30 in a cross-sectional view is equal to or greater than the width of the second elastic wiring 40, and is preferably greater than the width of the second elastic wiring 40.

The insulating layer 30 may be formed of at least one resin material selected from the group consisting of polyimide-based, epoxy-based, urethane-based, and acrylic-based resins. The insulating layer 30 may also be formed of an inorganic material such as alumina or silicon dioxide.

(First adhesive layer 50)
The first adhesive layer 50 is disposed so as to overlap at least a portion of the insulating layer 30 in the thickness direction X of the stretchable substrate 10. That is, the first adhesive layer 50 is disposed so as to overlap the wiring overlapping portions 70 (e.g. wiring intersection portions) of both the stretchable wires 20, 40 in the thickness direction X of the stretchable substrate.

The first adhesive layer 50 has adhesiveness that allows the stretchable device 100 to be attached to an adherend 300, such as a living body. In one example, the first adhesive layer 50 can be positioned between the stretchable substrate 10 and the adherend 300, such as a living body.

The first adhesive layer 50 has a first main surface 51 on the side of the adherend 300, such as a living body, and a second main surface 52 on the opposite side. It is preferable that the first adhesive layer 50 has adhesiveness on both main surfaces. The first main surface 51 of the first adhesive layer 50 can be attached to a living body or the like. Note that it is also possible for the first main surface 51 of the first adhesive layer 50 itself to be attached to another layer, and then the other layer to be attached to the living body or the like.

The second main surface 52 of the first adhesive layer 50 can be attached to the stretchable substrate 10. A protective layer, which will be described later, may be further disposed between the second main surface 52 of the first adhesive layer 50 and the stretchable substrate 10 from the standpoint of improving waterproofing, etc.

The first adhesive layer 50 can be made of any adhesive that is mild to the skin, has sufficient pressure-sensitive adhesive properties, and can be easily peeled off from the skin after use.

Although not particularly limited, the first adhesive layer 50 may be composed of a pressure-sensitive adhesive or the like. There is no particular limit to the pressure-sensitive adhesive, so long as it is one that can be laminated on the stretchable substrate 10 and generally used. For example, rubber-based, acrylic-based, and silicone-based pressure-sensitive adhesives can be used. When a pressure-sensitive adhesive is used, it can be bonded to the opposing member (stretchable substrate, protective layer described later) at a relatively low temperature, so that deterioration and distortion of the stretchable substrate 10 can be prevented by using excessive heat or UV energy.

Note that, although FIGS. 1 to 4 show an embodiment in which the insulating layer 30 and the first adhesive layer 50 have substantially the same width dimension, this is not limiting, and the width dimension of the first adhesive layer 50 may be greater than the width dimension of the insulating layer 30. In this case, it may be possible to alleviate stress generated in the stretchable device 100 due to the difference in the width dimensions of the two layers, compared to when the width dimensions of the two layers are substantially the same.

(Characteristic parts of the first embodiment)
The following describes the characteristics of the first embodiment, taking into account the main components of the stretchable device 100. The first embodiment is characterized in that the first adhesive layer 50 has a relatively smaller stretch performance (or stretchability or stretch rate) than the insulating layer 30, on the premise that the first adhesive layer 50 overlaps at least a portion of the insulating layer 30 in the thickness direction X of the stretchable substrate.

In this specification, "stretchability (or stretchability or stretch rate)" refers, in a broad sense, to the properties and ability of stretching of the adhesive layer (first adhesive layer/second adhesive layer described below) and insulating layer, which are components of a stretchable device, and in a narrow sense, to something that can be evaluated based on the difference in Young's modulus and/or thickness of each of these adhesive layer and insulating layer.

In addition, in this specification, "low elasticity" refers to a state in which it is difficult to stretch, and refers to a state in which the Young's modulus is large and/or the thickness is large. In other words, the larger the Young's modulus, the more difficult it is to stretch, and the larger the thickness, the more difficult it is to stretch, and this state is defined as having low elasticity. On the other hand, in this specification, a state in which it is easy to stretch, i.e., a state in which the Young's modulus is small and/or a state in which the thickness is small, can be defined as having high elasticity.

As an example, the Young's modulus of the first adhesive layer 50 is greater than the Young's modulus of the insulating layer 30. In the first embodiment, the width dimension of the first adhesive layer 50 and the width dimension of the insulating layer 30 are the same or substantially the same. In addition, the thickness direction dimension of the stretchable substrate 10 of the first adhesive layer 50 and the thickness direction dimension of the stretchable substrate 10 of the insulating layer 30 are also the same or substantially the same. That is, the cross-sectional area of the first adhesive layer 50 and the cross-sectional area of the insulating layer 30 can be the same or substantially the same.

According to the above characteristics, since the first adhesive layer 50 has a relatively smaller stretchability than the insulating layer 30, the first adhesive layer 50 can have a relatively harder property than the insulating layer 30. Therefore, when the stretchable device 100 stretches, the first adhesive layer 50 located at the wiring overlap portion 70 of both stretchable wirings 20, 40 is difficult to stretch. Accordingly, the localized portions of both stretchable wirings 20, 40 located at the mutual overlapping portions with the first adhesive layer 50, which is difficult to stretch, also become difficult to stretch.

This also makes it difficult for the insulating layer 30 located in the wiring overlap portion 70 between the first elastic wiring 20 and the second elastic wiring 40 to stretch. As a result, compared to the conventional embodiment (see Figures 16 and 17) in which the thickness of the insulating layer 30' may become thinner when the stretchable device 100' is stretched compared to before the stretching, it is possible to suppress a reduction in the thickness of the insulating layer 30 before and after the stretching of the stretchable device 100 (see Figures 3 and 4).

As a result, by suppressing the reduction in the thickness of the insulating layer 30, it is possible to suppress the decrease in IR (insulation resistance) between the two elastic wirings 20, 40. In other words, it is possible to suppress the occurrence of leakage voltage (or leakage current) between the two elastic wirings 20, 40.

This makes it possible to effectively suppress the occurrence of a voltage drop (e.g., 5V to 4V) in one of the two elastic wirings 20, 40 when the device expands or contracts, and an accompanying voltage increase (e.g., 0V to 1V) in the other of the two elastic wirings 20, 40. This makes it possible to stabilize the voltage of the two elastic wirings 20, 40 when the device expands or contracts, and thus makes it possible to stabilize the voltage supply to the functional components.

Therefore, according to the first embodiment, it is possible to maintain the functions of the device, such as sensing and signal communication. Furthermore, when the device is operated under high humidity and high temperature, it is possible to avoid the occurrence of short circuits due to ion migration and wiring contact at the wiring overlap portion 70 (e.g., wiring intersection portion) of both stretchable wirings, where the voltage difference between the two stretchable wirings becomes large when the wirings stretch.

In addition, from the viewpoint of suppressing the occurrence of ion migration, it is preferable that the first elastic wiring 20 and the second elastic wiring 40 have different electric potentials. Furthermore, according to the first embodiment, since the insulating layer 30 is merely located in the overlapping portion 70 between the first elastic wiring 20 and the second elastic wiring 40, a gap can be provided between the adherend 300, such as a living body, and the elastic substrate 10. This can also improve the breathability of the elastic device 100.

Above, the state of the stretchable device before and during stretching was explained using Figures 3 and 4. Hereafter, we will explain the modified example of the first embodiment and the second to fifth embodiments using drawings showing the state of the stretchable device during stretching.

In addition, two or more first adhesive layers 50 with different stretchability may be provided, provided that the stretchability is relatively smaller than that of the insulating layer 30. In this case, a relatively harder (super hard) first adhesive layer and a relatively harder (hard) first adhesive layer may be provided compared to the insulating layer 30. For example, the structure may be such that two first adhesive layers are stacked, or the structure may be such that two first adhesive layers are arranged side by side in the width direction.

[Modification 1 of the First Embodiment]
Hereinafter, the configuration of the modified example 1 of the stretchable device according to the first embodiment will be described with reference to Fig. 5. The modified example 1 of the first embodiment is different from the first embodiment (see Figs. 3 and 4) in the form of the first adhesive layer 50A.

Figure 5 is a partially enlarged schematic cross-sectional view of modified example 1 of the stretchable device according to the first embodiment of the present invention (corresponding to the cross-sectional view taken along line X-X in Figure 2).

As shown in FIG. 5, the thickness of the first adhesive layer 50A is greater than the thickness of the insulating layer 30. In this case, the Young's modulus of the first adhesive layer 50A is smaller than the Young's modulus of the insulating layer 30. That is, a first adhesive layer 50A that is relatively softer and thicker than the first adhesive layer 50 shown in FIG. 3 and FIG. 4 can be used. In addition, it is preferable that the width of the first adhesive layer 50A is greater than the width of the insulating layer 30.

By adopting such a configuration, the first adhesive layer 50A can provide a relatively smaller stretchability than the insulating layer 30. This makes it difficult for the insulating layer 30 located in the overlapping portion between the first elastic wiring 20 and the second elastic wiring 40 to stretch. As a result, the reduction in the thickness of the insulating layer 30 before and after the stretching of the stretchable device 100A is suppressed, and thereby the decrease in the IR (insulation resistance) between the two elastic wirings 20, 40 can be suppressed.

It goes without saying that if the first adhesive layer 50A has a relatively smaller elasticity than the insulating layer 30, the Young's modulus of the first adhesive layer 50A may be greater than the Young's modulus of the insulating layer 30.

[Modification 2 of the First Embodiment]
Hereinafter, the configuration of the second modified example of the stretchable device according to the first embodiment will be described with reference to Fig. 6. The second modified example of the first embodiment is different from the first embodiment (see Figs. 3 and 4) in the location of the first adhesive layer 50B.

Figure 6 is a partially enlarged schematic cross-sectional view of variant 2 of the stretchable device according to the first embodiment of the present invention (corresponding to the cross-sectional view taken along line X-X in Figure 2).

As shown in FIG. 6 , in the second variant, the stretchable device 100B may further include a protective layer 60.
The second elastic wire 40 has a first side 41 facing the insulating layer and a second side 42 opposite to the first side 41. In this case, from the viewpoint of ensuring biocompatibility and insulation and waterproofing, it is preferable that the protective layer 60 contacts the second side 42 of the second elastic wire 40. Also, as shown in FIG. 6, in one example, the protective layer 60 can be disposed so as to contact the first elastic wire 20. However, without being limited thereto, a gap may be provided between the protective layer 60 and the first elastic wire 20 in a cross-sectional view.

In light of the above, the protective layer 60 may be formed from a resin material having elasticity. For example, the protective layer 60 may be formed from a polyester-based resin, a styrene-based resin, an olefin-based resin, an epoxy-based resin, a urethane-based resin, an acrylic-based resin, or a silicone-based resin.

In this configuration, the first adhesive layer 50B can be positioned between the protective layer 60 and the adherend 300, such as a living body. That is, compared to the first adhesive layer 50 shown in Figures 3 and 4, the first adhesive layer 50B in Modification 2 can be positioned between the protective layer 60 and the adherend 300, such as a living body, rather than the stretchable substrate 10. Note that, like the first adhesive layer 50 shown in Figures 3 and 4, the first adhesive layer 50B in Modification 2 is also assumed to provide a relatively smaller stretch performance than the insulating layer 30.

As a result, even in the second modified example, the insulating layer 30 located in the overlapping portion between the first elastic wiring 20 and the second elastic wiring 40 is less likely to stretch. As a result, the reduction in the thickness of the insulating layer 30 before and after the stretching of the stretchable device 100B is suppressed, and thereby the decrease in the IR (insulation resistance) between the two elastic wirings 20, 40 can be suppressed.

In the first embodiment and its modified examples 1 and 2, it is preferable that the thickness of the first adhesive layer 50 is constant from the viewpoint of favorable adhesion to both the stretchable substrate 10 and the adherend 300 such as a living body. As described above, the first adhesive layer 50 can be provided with the characteristic of being relatively harder than the insulating layer 30 by adjusting the properties (Young's modulus) of the first adhesive layer 50 itself and the thickness of the first adhesive layer 50 itself. In other words, the first adhesive layer 50 is technically different from the previous embodiment in that it can be provided with the characteristic of being relatively harder than the insulating layer 30 even if it does not have a separate reinforcing member inside.

[Second embodiment]
Hereinafter, the configuration of a stretchable device according to the second embodiment will be described with reference to Fig. 7. Compared to the first embodiment (see Figs. 3 and 4), the second embodiment differs in that at least two types of adhesive layers are used.

Figure 7 is a partially enlarged schematic cross-sectional view of a stretchable device according to a second embodiment of the present invention (corresponding to the cross-sectional view taken along line X-X in Figure 2).

In the second embodiment, a second adhesive layer 52C is further used in addition to the first adhesive layer 51C. Specifically, as shown in FIG. 7, the second adhesive layer 52C faces at least one side of the first adhesive layer 51C in a cross-sectional view, and may have a Young's modulus different from that of the first adhesive layer 51C.

In addition, compared to the properties of the insulating layer 30, the second adhesive layer 52C may have a relatively smaller elasticity than the insulating layer 30. For example, the second adhesive layer 52C may have a relatively smaller Young's modulus than the insulating layer 30.

In this configuration, compared to the first embodiment, the first adhesive layer 51C and the second adhesive layer 52C can be arranged in parallel adjacent to each other. This makes it possible to increase the proportion of the adhesive layer in the area between the stretchable substrate 10 and the adherend 300 such as a living body. In addition, it is possible to make the thickness of the area between the stretchable substrate 10 and the adherend 300 such as a living body uniform overall when the stretchable device 100 stretches.

As a result, compared to the case where only the first adhesive layer is disposed in the first embodiment, in a cross-sectional view, it is possible to suppress unintentional local curvature or bending of the stretchable device 100C (specifically, the stretchable substrate 10, the stretchable wiring 20, 40) toward the adherend 300 during stretching on at least one side of the first adhesive layer 51C. As a result, it is possible to improve the overall strength of the stretchable device 100C.

From the viewpoint of further improving the uniformity of the thickness of the region between the stretchable substrate 10 and the adherend 300 such as a living body during stretching, it is preferable that the second adhesive layer 52C contacts the first adhesive layer 51C as shown in FIG. 7. Without being limited thereto, in another example, the first adhesive layer and the second adhesive layer 52 can be arranged to be spaced apart from each other and to face each other as shown in the modified example described later.

[Modification 1 of the second embodiment]
Hereinafter, the configuration of the modified example 1 of the stretchable device according to the second embodiment will be described with reference to Fig. 8. The modified example 1 of the second embodiment is different from the second embodiment (see Fig. 7) in the width dimension of the first adhesive layer.

Figure 8 is a partially enlarged schematic cross-sectional view of modified example 1 of the stretchable device according to the second embodiment of the present invention (corresponding to the cross-sectional view taken along line X-X in Figure 2).

In the first modified example of the second embodiment, as shown in FIG. 8, the width of the first adhesive layer 51D is smaller than the width of the insulating layer 30 in a cross-sectional view. In other words, the first adhesive layer 51D and the second adhesive layer 52D can overlap with the insulating layer 30 in the thickness direction X of the stretchable substrate 10.

With this configuration, the width of the first adhesive layer 51D is smaller than the width of the insulating layer 30, so that stress concentration on the first adhesive layer 51D, which has relatively rigid properties, can be suppressed when the stretchable device 100D stretches.

In other words, when the stretchable device 100D shown in FIG. 7 stretches, the stress applied to the first adhesive layer 51D, which has a relatively hard property, can be alleviated compared to when the width of the first adhesive layer 51C and the width of the insulating layer 30 are the same or substantially the same, as shown in FIG. 7.

When the width of the first adhesive layer and the width of the insulating layer are the same or substantially the same, the points of stress concentration in the stretchable device may be the interface between the first adhesive layer and a component member in contact with it in the width direction, and the interface between the insulating layer and a component member in contact with it in the width direction.

In contrast, in this embodiment, the first adhesive layer 51D and the second adhesive layer 52D overlap with the insulating layer 30 in the thickness direction X of the stretchable substrate 10, and the relatively soft insulating layer 30 causes the influence of the first adhesive layer 51D, which has the harder properties, to be strong in the overlapping region between the first adhesive layer 51D and the insulating layer 30 in the thickness direction X of the stretchable substrate 10. The influence of the second adhesive layer 52D, which has the harder properties, is strong in the overlapping region between the second adhesive layer 52D and the insulating layer 30. In the thickness direction X of the stretchable substrate 10, in the region where the second adhesive layer 52D and the insulating layer 30 do not overlap, the influence of the second adhesive layer 52D acts.

From the above, by increasing the Young's modulus of the second adhesive layer 52D, the insulating layer 30, and the first adhesive layer 51D in that order, the ease of stretching can be gradually changed, thereby further reducing stress in the stretchable device.

[Modification 2 of the second embodiment]
Hereinafter, the configuration of the modified example 2 of the stretchable device according to the second embodiment will be described with reference to Fig. 9. The modified example 2 of the second embodiment is different from the second embodiment and its modified example 1 (see Figs. 7 and 8) in terms of the arrangement of the first adhesive layer 51E and the second adhesive layer 52E.

Figure 9 is a partially enlarged schematic cross-sectional view of variant 2 of the stretchable device according to the second embodiment of the present invention (corresponding to the cross-sectional view taken along line X-X in Figure 2).

Specifically, in a cross-sectional view, the second adhesive layer 52E can be separated from the first adhesive layer 51E. With this configuration, the parallel arrangement of the first adhesive layer 51E and the second adhesive layer 52E can improve the uniformity of the thickness of the area between the stretchable substrate 10 and the adherend 300 such as a living body when the stretchable device 100E is stretched. In addition, the separation of the second adhesive layer 52E and the first adhesive layer 51E can provide a gap (corresponding to a physical space), which can improve the breathability between the adherend 300 such as a living body and the stretchable substrate 10.

[Third embodiment]
Hereinafter, a configuration of a stretchable device according to the third embodiment will be described with reference to Fig. 10 and Fig. 11. The third embodiment is different from the first embodiment (see Figs. 3 and 4) in that there are a plurality of wiring overlapping portions 70F.

Figure 10 is a plan view showing a stretchable device according to a third embodiment of the present invention. Figure 11 is a partially enlarged schematic cross-sectional view of the stretchable device according to the third embodiment of the present invention taken along line segment Y-Y in Figure 10.

As shown in FIG. 10, the third embodiment is based on the premise that there are multiple wiring overlapping portions 70F. In this specification, each of the multiple elastic wirings that overlap with the first elastic wiring 20 corresponds to the second elastic wirings 41 to 43 described above.

In this case, as shown in FIG. 11, the first adhesive layer 50F may overlap the insulating layer 30F at the multiple wiring overlapping portions 70F in the thickness direction X of the stretchable substrate. In one example, as shown in FIG. 11, the insulating layer 30F and the first adhesive layer 50F overlapping the insulating layer 30F may be positioned at each of the multiple wiring overlapping portions 70F.

As in the first embodiment, in the third embodiment, each first adhesive layer 50F overlaps with the insulating layer 30 in the thickness direction X of the stretchable substrate 10, and has a relatively smaller stretchability than each insulating layer 30F. With this configuration, the insulating layer 30 located in each wiring overlap portion 70F is also less likely to stretch, so that the reduction in thickness of each insulating layer 30F before and after stretching of the stretchable device 100F can be suppressed compared to the previous embodiment (see Figures 16 and 17) (see Figures 10 and 11).

From the above, even when there are multiple wiring overlapping portions 70F, the reduction in the thickness of each insulating layer 30F can be suppressed to suppress the decrease in IR (insulation resistance) between the elastic wirings 20, 40 in each wiring overlapping portion 70F. In other words, the occurrence of leakage current between the elastic wirings 20, 40 in each wiring overlapping portion 70F can be suppressed.

In addition, in the third embodiment, multiple first adhesive layers 50F can be spaced apart at a predetermined interval, so that multiple gaps can be formed at predetermined intervals between the adherend 300, such as a living body, and the stretchable substrate 10. This can improve the breathability between the adherend 300, such as a living body, and the stretchable substrate 10.

[Fourth embodiment]
Hereinafter, the configuration of a stretchable device according to the fourth embodiment will be described with reference to Fig. 12 and Fig. 13. Compared with the third embodiment (see Fig. 10 and Fig. 11), the fourth embodiment is different in that one insulating layer and one first adhesive layer are positioned so as to straddle a plurality of wiring overlapping portions.

Figure 12 is a plan view showing a stretchable device according to a fourth embodiment of the present invention. Figure 13 is a partially enlarged schematic cross-sectional view of the stretchable device according to the fourth embodiment of the present invention taken along line Z-Z in Figure 12.

As shown in Figures 12 and 13, in the fourth embodiment, one insulating layer 30G spanning multiple wiring overlapping portions 70G and a first adhesive layer 50G overlapping the one insulating layer 30G can be positioned.

Compared to the third embodiment, this configuration allows the material of the first adhesive layer to be continuously supplied to the main surface of the stretchable substrate 10 all at once when manufacturing a stretchable device 100G including multiple wiring overlapping portions 70G. Furthermore, the material of the insulating layer can be continuously supplied to the main surface of the first stretchable wiring 20 all at once.

As a result, the manufacturing process of the stretchable device 100G including multiple wiring overlapping portions 70G can be simplified, thereby improving the manufacturing efficiency of the stretchable device 100G according to the fourth embodiment.

In addition, in the fourth embodiment, one insulating layer 30G is arranged to straddle multiple wiring overlapping portions 70G, so that contact between the first elastic wiring 20 and each of the second elastic wirings 41 to 43 can be more suitably suppressed. This makes it possible to more suitably suppress the occurrence of ion migration and the occurrence of short circuits.

Furthermore, in the fourth embodiment, one first adhesive layer 50G is positioned so as to straddle a plurality of wiring overlapping portions 70G, so that the area of the first adhesive layer 50G between the adherend 300, such as a living body, and the stretchable substrate 10 can be made wider. This increases the connection strength with the stretchable substrate 10,
It is possible to improve the strength of the stretchable device 100G. In addition, since the adhesive region to the adherend 300 such as a living body is widened, it becomes easier to hold the stretchable device 100G to the adherend 300 such as a living body.

[Fifth embodiment]
Hereinafter, the configuration of a stretchable device according to the fifth embodiment will be described with reference to Fig. 14 and Fig. 15. The fifth embodiment is different from the first embodiment (see Figs. 1 to 4) in that electronic components are mounted on the stretchable device.

Figure 14 is a plan view showing a stretchable device according to a fifth embodiment of the present invention. Figure 15 is a partially enlarged schematic cross-sectional view of the stretchable device according to the fifth embodiment of the present invention taken along line segment W-W in Figure 14.

As shown in Figures 14 and 15, in the fifth embodiment, an electronic component 200 is mounted, and the electronic component 200 overlaps the first adhesive layer 50H in the thickness direction X of the stretchable substrate 10. The electronic component 200 is connected to the first stretchable wiring 20 via the land 210.

By adopting such a configuration, in the fifth embodiment, the first adhesive layer 50H overlaps the electronic component 200 in addition to the insulating layer 30 in the thickness direction X of the stretchable substrate 10, and has a relatively smaller stretchability than the insulating layer 30F. Therefore, both the insulating layer 30F and the land 210 overlapping with the first adhesive layer 50H are less likely to stretch. This makes it possible to suppress the decrease in IR between the stretchable wirings 20 and 40 in the wiring overlapping portion 70 by suppressing the reduction in the thickness of the insulating layer 30F before and after the stretchable device 100H is stretched. In addition, it is possible to suppress the breakage of the electronic component 200 connected to the stretchable device 100H via the land 210 before and after the stretchable device 100H is stretched (see Figures 14 and 15).

When an electronic component is mounted on a stretchable device, a process of adding a resin material to cover the electronic component 200 and the land 210 (potting process) may usually be required to prevent the land 210 from expanding or contracting when the device expands or contracts, and to protect the electronic component 200 connected to the land 210.

In this regard, as described above, in the fifth embodiment, the expansion and contraction of the land 210 before and after the expansion and contraction of the stretchable device 100H and the associated disconnection of the electronic component 200 can be suppressed. Therefore, it is not necessary to perform the potting process described above. By not requiring the implementation of such a process, it is possible to prevent the occurrence of chemical attack and reduce the height of the electronic component 200.

Note 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 the components, and does not limit the shape. Also, partial substitution or combination of the configurations shown in different embodiments and modifications is possible.

The stretchable device according to one embodiment of the present invention may have the following features.
＜1＞
A stretchable device comprising: a stretchable substrate; a first stretchable wiring and a second stretchable wiring provided on the stretchable substrate and partially overlapping each other in a thickness direction of the stretchable substrate; an insulating layer disposed in a wiring overlap portion between the first stretchable wiring and the second stretchable wiring; and a first adhesive layer overlapping at least a portion of the insulating layer in the thickness direction, wherein the first adhesive layer has a stretchability relatively smaller than that of the insulating layer.
＜2＞
The stretchable device according to <1>, wherein the first stretchable wiring and the second stretchable wiring intersect with each other in the wiring overlap portion.
＜3＞
The stretchable device according to <1> or <2>, wherein the Young's modulus of the first adhesive layer is greater than the Young's modulus of the insulating layer.
＜4＞
The stretchable device according to any one of <1> to <3>, wherein the first adhesive layer is located between the stretchable substrate and an adherend.
＜5＞
The stretchable device according to any one of <1> to <4> further comprises a protective layer, the second stretchable wiring has a first side facing the insulating layer and a second side opposite to the first side, the protective layer contacts the second side, and the first adhesive layer is located between the protective layer and the adherend.
＜6＞
The stretchable device according to any one of <1> to <5>, further comprising the second adhesive layer, the second adhesive layer facing at least one side of the first adhesive layer in a cross-sectional view, and having a Young's modulus different from that of the first adhesive layer.
＜７＞
The stretchable device according to <6>, wherein the second adhesive layer has a relatively smaller stretchability than the insulating layer.
＜8＞
The stretchable device according to <6> or <7>, wherein the Young's modulus of the second adhesive layer is smaller than the Young's modulus of the insulating layer.
＜9＞
The stretchable device according to any one of <6> to <8>, wherein the second adhesive layer is separated from the first adhesive layer.
＜10＞
The stretchable device according to any one of <6> to <9>, wherein the second adhesive layer is in contact with the first adhesive layer.
<11>
The stretchable device according to any one of <6> to <10>, wherein the second adhesive layer overlaps the insulating layer in a thickness direction of the stretchable substrate.
＜12＞
The stretchable device according to <11>, wherein, in a cross-sectional view, a width of the first adhesive layer is smaller than a width of the insulating layer.
＜13＞
The wiring overlapping portions are present in a plurality of portions, and the insulating layer and the first adhesive layer overlapping the insulating layer are positioned in each of the plurality of wiring overlapping portions in the thickness direction of the stretchable substrate. The stretchable device according to any one of <1> to <12>.
＜14＞
The wiring overlapping portions are multiple, and in the thickness direction of the stretchable substrate, one insulating layer spanning the multiple wiring overlapping portions and the first adhesive layer overlapping the one insulating layer are positioned. The stretchable device according to any one of <1> to <13>.
＜15＞
The stretchable device according to any one of <1> to <14>, wherein a thickness of the first adhesive layer is greater than a thickness of the insulating layer.
＜16＞
The stretchable device according to <15>, wherein when a thickness of the first adhesive layer is greater than a thickness of the insulating layer, the Young's modulus of the first adhesive layer is smaller than the Young's modulus of the insulating layer.
＜１７＞
The stretchable device according to <16>, wherein, in a cross-sectional view, the width of the first adhesive layer is larger than the width of the insulating layer.
＜18＞
The stretchable device according to any one of <1> to <17>, wherein an electronic component can be mounted, and the electronic component overlaps the first adhesive layer in the thickness direction of the stretchable substrate.
＜19＞
The stretchable device according to any one of <1> to <18>, wherein the first stretchable wiring and the second stretchable wiring have different potentials.
＜20＞
The stretchable device according to any one of <1> to <19>, wherein the first adhesive layer has a constant thickness.

300 Adherend 300 (living body, etc.)

200, 201, 202 Electronic components

100, 100A to 100H, 100' Stretchable device

10,10' Stretchable base material

20, 20' 1st elastic wiring

30, 30F, 30G, 30' Insulating layer

40, 40', 41-43 2nd elastic wiring

50, 50A, 50B, 51C, 51D, 51E, 50F, 50G, 50H, 50' First adhesive layer 52C, 52D, 52E Second adhesive layer

60 Protective layer

70, 70F, 70G Wiring overlapping area

X: thickness direction of the elastic substrate

Claims (20)

A stretchable device comprising: a stretchable substrate; a first stretchable wiring and a second stretchable wiring provided on the stretchable substrate and partially overlapping each other in a thickness direction of the stretchable substrate; an insulating layer disposed in a wiring overlap portion between the first stretchable wiring and the second stretchable wiring; and a first adhesive layer overlapping at least a portion of the insulating layer in the thickness direction, the first adhesive layer having a relatively smaller stretchability than the insulating layer, and being composed of an adhesive . The stretchable device according to claim 1, wherein the first stretchable wiring and the second stretchable wiring cross each other in the wiring overlap portion. The stretchable device of claim 1, wherein the Young's modulus of the first adhesive layer is greater than the Young's modulus of the insulating layer. The stretchable device according to claim 1, wherein the first adhesive layer is located between the stretchable substrate and the adherend. The stretchable device according to claim 1, further comprising a protective layer, the second stretchable wiring having a first side facing the insulating layer and a second side opposite the first side, the protective layer contacting the second side, and the first adhesive layer being located between the protective layer and the adherend. 2. The stretchable device of claim 1, further comprising a second adhesive layer, the second adhesive layer facing at least one side of the first adhesive layer in a cross-sectional view and having a different Young's modulus than the first adhesive layer. The stretchable device according to claim 6, wherein the second adhesive layer has a relatively smaller stretchability than the insulating layer. The stretchable device according to claim 7, wherein the Young's modulus of the second adhesive layer is smaller than the Young's modulus of the insulating layer. The stretchable device of claim 6, wherein the second adhesive layer is spaced apart from the first adhesive layer. The stretchable device of claim 6, wherein the second adhesive layer is in contact with the first adhesive layer. The stretchable device according to claim 6, wherein the second adhesive layer overlaps with the insulating layer in the thickness direction of the stretchable substrate. The stretchable device of claim 11, wherein the width of the first adhesive layer is smaller than the width of the insulating layer in a cross-sectional view. The stretchable device according to claim 1, wherein there are a plurality of the wiring overlapping portions, and the insulating layer and the first adhesive layer overlapping the insulating layer are positioned at each of the plurality of wiring overlapping portions in the thickness direction of the stretchable substrate. The stretchable device according to claim 1, wherein there are a plurality of the wiring overlapping portions, and one of the insulating layers is positioned across the plurality of wiring overlapping portions in the thickness direction of the stretchable substrate, and the first adhesive layer is positioned over the one insulating layer. The stretchable device of claim 1, wherein the thickness of the first adhesive layer is greater than the thickness of the insulating layer. The stretchable device according to claim 15, wherein when the thickness of the first adhesive layer is greater than the thickness of the insulating layer, the Young's modulus of the first adhesive layer is smaller than the Young's modulus of the insulating layer. The stretchable device of claim 16, wherein the width of the first adhesive layer is greater than the width of the insulating layer in a cross-sectional view. The stretchable device according to claim 1, in which an electronic component can be mounted, and the electronic component overlaps the first adhesive layer in the thickness direction of the stretchable substrate. The stretchable device according to claim 1, wherein the first stretchable wiring and the second stretchable wiring have different electric potentials. The stretchable device of claim 1, wherein the thickness of the first adhesive layer is constant.

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