Stretchable Devices

Abstract

This stretchable device comprises: a first base material; a stretchable first wiring provided on the first base material; a second base material opposing the first base material in a first direction which is the thickness direction of the first base material; a second wiring provided on the second base material and opposing the first wiring in the first direction; a connection member that electrically connects the first wiring and the second wiring; and a first protection layer disposed at least between the second base material and the first wiring in the first direction.

Description

[Technical field]

[0001] The present disclosure relates to stretchable devices. [Background technology]

[0002] 2. Description of the Related Art Conventionally, it has been common to electrically connect a plurality of substrates having electrodes and wiring provided on their main surfaces.

[0003] Patent Document 1 describes a bonding device and a bonding method for connecting electrode terminals between substrates via a conductive connecting material. Specifically, a first electrode terminal provided on a first substrate and a second electrode terminal provided on a second substrate are disposed to face each other and are connected by thermal compression bonding using a heater bar. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2007-35546 A Summary of the Invention Problem that the invention is trying to solve

[0005] However, when connecting a stretchable wire as a first electrode terminal and an electrode or wire as a second electrode terminal, if the connection method described in Patent Document 1 is used, the second substrate on which the electrode or wire is provided may come into contact with the stretchable wire, which may cause the stretchable wire to break. Alternatively, the contact of the second substrate may hinder the stretching of the stretchable wire, which may become the starting point for breakage. In other words, the direct contact of the second substrate with the stretchable wire may make the stretchable wire more likely to break.

[0006] Therefore, the present disclosure provides a stretchable device that can connect substrates while reducing the possibility of breakage of the stretchable wiring. [Means for solving the problem]

[0007] In order to achieve the above object, a stretchable device according to one aspect of the present disclosure includes: A first substrate; A first wiring having elasticity provided on the first base material; a second base material facing the first base material in a first direction which is a thickness direction of the first base material; a second wiring provided on the second base material and facing the first wiring in the first direction; a connection member that electrically connects the first wiring and the second wiring; A first protective layer is disposed at least between the second substrate and the first wiring in the first direction. Effect of the Invention

[0008] According to a stretchable device according to an aspect of the present disclosure, substrates can be connected to each other while reducing the possibility of breakage. [Brief description of the drawings]

[0009] [Figure 1A] FIG. 1A is a partially enlarged top view diagrammatically illustrating a stretchable device according to a first embodiment of the present disclosure. [Figure 1B] FIG. 1B is a cross-sectional view taken along line AA in FIG. 1A. [Diagram 2] FIG. 2 is an exploded plan view illustrating a schematic diagram of a stretchable device according to a first embodiment of the present disclosure. [Diagram 3] FIG. 3 is a cross-sectional view of a stretchable device according to a first modified example of the first embodiment of the present disclosure. [Figure 4] FIG. 4 is a cross-sectional view of a stretchable device according to a second modified example of the first embodiment of the present disclosure. [Diagram 5] FIG. 5 is a cross-sectional view of a stretchable device according to a third modified example of the first embodiment of the present disclosure. [Figure 6] FIG. 6 is a cross-sectional view of a stretchable device according to a fourth modified example of the first embodiment of the present disclosure. [Figure 7] FIG. 7 is a cross-sectional view of a stretchable device according to a fifth modified example of the first embodiment of the present disclosure. [Figure 8A] FIG. 8A is a partially enlarged top view of a stretchable device according to a sixth modified example of the first embodiment of the present disclosure. [Figure 8B] FIG. 8B is a cross-sectional view taken along line AA in FIG. 8A. [Figure 8C] FIG. 8C is a cross-sectional view taken along line BB in FIG. 8A. [Figure 8D] FIG. 8D is an exploded plan view of a stretchable device according to a sixth modified example of the first embodiment of the present disclosure. [Figure 9] FIG. 9 is a cross-sectional view of a stretchable device according to a second embodiment of the present disclosure. [Figure 10] FIG. 10 is a partial cross-sectional view of a stretchable device according to a first modified example of the second embodiment of the present disclosure. [Figure 11] FIG. 11 is a partial cross-sectional view of a stretchable device according to a second modified example of the second embodiment of the present disclosure. [Figure 12] FIG. 12 is a partial cross-sectional view of a stretchable device according to a third modified example of the second embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, the embodiments of the present disclosure 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 the independent claims will be described as optional components. In addition, the size and size ratio of the components shown in the drawings are not necessarily strict. In addition, in each figure, substantially the same configuration is given the same symbol, and duplicated descriptions may be omitted or simplified.

[0011] [First embodiment] The structure of the stretchable device 100 according to the first embodiment will be described with reference to Figs. 1A, 1B, and 2. Fig. 1A is a partial top view of the stretchable device 100. Fig. 1B is a cross-sectional view of the stretchable device 100 taken along line AA in Fig. 1A. Fig. 2 is an exploded plan view of the stretchable device 100. Note that the cross-sectional views in this specification are cross-sectional views parallel to the first direction, including an area where the first substrate 1 and the second substrate 3 overlap, as viewed from the first direction, which is the thickness direction of the first substrate. The first direction is indicated by a double-headed arrow X in Fig. 1B. As shown in Fig. 1B, the thickness direction of the first substrate 1, the thickness direction of the second substrate 2, and the first direction coincide with each other.

[0012] The stretchable device 100 includes a first substrate 1, a second substrate 3, a first wiring 2, a second wiring 4, a connection member 5, and a first protective layer 6. The first substrate 1 and the second substrate 3 are connected via the connection member 5. More specifically, the first wiring 2 provided on the first substrate 1 and the second wiring 4 provided on the second substrate 3 are electrically connected via the connection member 5. The first protective layer 6 is disposed between the second substrate 3 and the first wiring 2 in the first direction. Note that in FIG. 1A and FIG. 2, the connection member 5 and the first protective layer 6 are shown by hatching with dots for convenience.

[0013] The shape of the stretchable device 100 is not particularly limited. In this specification, a structure in which two substrates are connected is described as an example, but three or more substrates may be connected. The first wiring 2 is not limited to the arrangement as shown in FIG. 1, and the extension direction is not limited either. Specifically, the longitudinal direction of the first substrate 1 and the extension direction of the first wiring 2 may not coincide, and the first wiring 2 may not extend in one direction. The number of the first wiring 2 is not particularly limited, and may be one or more. When there are more than one first wiring 2, the first wiring 2 may include a wiring that is not electrically connected to the second wiring 4. The same applies to the arrangement and number of the second wiring 4.

[0014] In addition, "above" in this specification does not have to coincide with the top and bottom when the stretchable device 100 is in use. More specifically, as shown in FIG. 1, since the first wiring 2 and the second wiring 4 can be electrically connected, "on the first substrate 1" refers to the main surface side of the first substrate 1 that is closer to the second substrate 3, and "on the second substrate 3" refers to the main surface side of the second substrate 3 that is closer to the first substrate 1. In addition, "above" an element includes not only an upper side away from the element, that is, an upper position via another object on the element or an upper position with a space therebetween, but also a position directly above the element that is in contact with the element.

[0015] The following describes these components and their arrangement. As shown in Figures 1A, 1B, and 2, the first substrate 1 and the second substrate 3 face each other in a first direction and partially overlap each other when viewed from the first direction. Similarly, the first wiring 2 and the second wiring 4 face each other in the first direction.

[0016] The first base material 1 is preferably a base material having elasticity. When the first base material 1 has elasticity, it is possible to reduce the risk of breakage due to expansion and contraction during use of the stretchable device 100 without suppressing the expansion and contraction of the first wiring 2.

[0017] An example of the stretchable substrate is a sheet-like or film-like substrate made of a stretchable resin material. Examples of the resin material include thermoplastic polyurethane. The thickness of the stretchable substrate 1 is not particularly limited, but from the viewpoint of not inhibiting the stretching of the surface of the living body when attached to the living body, it is preferably 1 mm or less, more preferably 100 μm or less, and even more preferably 50 μm or less. In addition, the thickness of the stretchable substrate 1 is preferably 1 μm or more.

[0018] The first base material 1 does not have to be stretchable. Specific examples include sheet- or film-shaped base materials such as PET and polyimide, and substrates such as FPC (Flexible Printed Circuit), FFC (Flexible Flat Cable), and PCB (Printed Circuit Board).

[0019] The first substrate 1 also has a first substrate end 11. The first substrate end 11 is an end of the first substrate 1 that is closer to the second substrate 3, in other words, an end that overlaps with the second wiring 4 when viewed from the first direction. Specifically, of both ends in the up-down direction in FIG. 1A, it is an end that is closer to the second substrate 3, and of both ends in the left-right direction in FIG. 1B, it is an end that is closer to the second substrate 3. Note that ends different from the first substrate end 11 are not shown in FIGS. 1A and 1B.

[0020] The first wiring 2 has elasticity, and may be, for example, a mixture of metal powder such as Ag, Cu, Ni, etc. as conductive particles and an elastomer resin such as 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. The conductive particles are preferably spherical in shape. The thickness, width, and length of the first wiring are not particularly limited.

[0021] The second substrate 3 has a larger Young's modulus than the first wiring 2. The second substrate 3 does not have to be elastic. Specific examples include substrates such as FPC, FFC, and PCB. By making the Young's modulus larger than that of the first wiring 2, pressure can be applied more easily to the joint during compression bonding, enabling bonding at a low pressure. In other words, by reducing the pressure, damage to the substrate during bonding can be reduced. In addition, it is preferable that the second substrate 3 has a larger Young's modulus than the first substrate 1. Since the second substrate 3 is more resistant to impacts during connection, the connection reliability can be further improved.

[0022] The second substrate 3 also has a second substrate end 31. The second substrate end 31 is an end of the second substrate 3 closer to the first substrate 1, in other words, an end that overlaps with the first wiring 2 when viewed from the first direction. Specifically, of both ends in the up-down direction in FIG. 1A, it is an end closer to the first substrate 1, and of both ends in the left-right direction in FIG. 1B, it is an end closer to the first substrate 1. Note that ends different from the second substrate end 31 are not shown in FIG. 1A and FIG. 1B.

[0023] As described above, since the second substrate 3 has a higher Young's modulus than the first wiring 2, there is a risk of the first wiring 2 breaking when the first wiring 2 comes into direct contact with the second substrate 3. In addition to breakage due to direct contact, the stretching performance of the portion in contact with the second substrate 3 is significantly reduced, so that the portion becomes a point of stress concentration during stretching, which may result in breakage.

[0024] The second wiring 4 is a wiring having a larger Young's modulus than the first wiring 2. For example, it may be a metal wiring such as a copper foil. The thickness of the wiring is preferably 1 μm or more and 100 μm or less.

[0025] As described above, the connection member 5 electrically connects the first wiring 2 and the second wiring 4. Examples of the connection member 5 include ACF (Anisotropic Conductive Film), conductive paste, solder, and the like. The connection member 5 preferably contains resin and conductive particles. The conductive particles contained in the connection member 5 come into contact with the first wiring 2 and the second wiring 4, thereby electrically connecting the first wiring 2 and the second wiring 4. Furthermore, the resin contained in the connection member 5 covers the first wiring 2, thereby reducing exposure of the first wiring 2 and suppressing contact between the first wiring 2 and the second substrate 4.

[0026] The first protective layer 6 is disposed between the second substrate 3 and the first wiring 2 in the first direction. Specifically, the first protective layer 6 covers a portion of the first wiring 2 and overlaps with the second substrate end 31 when viewed from the first direction. With this arrangement, contact between the second substrate 3 and the first wiring 2 can be reduced, and breakage of the first wiring 2 can be suppressed.

[0027] Specifically, the second substrate 3 may be deformed toward the first substrate 1 due to an external force or pressure bonding, which will be described later. If the first wiring 2 is exposed at this time, the first wiring 2 may come into contact with the second substrate 3, causing the first wiring 2 to break. By providing the first protective layer 6, it is possible to suppress contact between the first wiring 2 and the second substrate 3.

[0028] Specifically, the first protective layer 6 is preferably made of a resin material or a mixture of a resin material and an inorganic material. Examples of the resin material include urethane, styrene, olefin, silicone, fluorine, nitrile rubber, latex rubber, vinyl chloride, ester, amide, and other elastomer resins, epoxy, phenol, acrylic, polyester, imide, rosin, cellulose, polyethylene terephthalate, polyethylene naphthalate, and polycarbonate resins. The first protective layer 6 is preferably insulating. By making the first protective layer 6 insulating, ion migration of the first wiring 6 can be more reliably suppressed. The first protective layer 6 may be made of the same material as the first substrate 1.

[0029] The first protective layer 6 includes a first protective layer upper surface 61 closest to the second base material 3, a first protective layer lower surface 62 closest to the first base material 1, and a first protective layer end surface 63 connecting the first protective layer upper surface 61 and the first protective layer lower surface 62. The first protective layer end surface 63 is the surface that is closest to the end of the first wiring 2 among the surfaces connecting the first protective layer upper surface 61 and the first protective layer lower surface 62. The first protective layer upper surface 61 corresponds to the upper surface in the claims, the first protective layer lower surface 62 corresponds to the lower surface in the claims, and the first protective layer end surface 63 corresponds to the end surface in the claims.

[0030] Furthermore, the thickness of the first protective layer 6 is preferably 1 μm or more and 100 μm or less, and more preferably 50 μm or less. By making the thickness of the first protective layer 6 1 μm or more, contact between the first wiring 2 and the second base material 3 can be suppressed. Furthermore, by making the thickness of the first protective layer 6 100 μm or less, the overall height can be reduced. Note that, when the thickness of the first protective layer 6 is not constant, the maximum dimension of the first protective layer 6 in the first direction is taken as the thickness.

[0031] Therefore, a stretchable device 100 is provided that includes a first substrate 1, a first wiring 2 having stretchability and provided on the first substrate 1, a second substrate 3 facing the first substrate 1 in a first direction which is the thickness direction of the first substrate 1, a second wiring 4 provided on the second substrate 3 and facing the first wiring 2 in the first direction, a connection member 5 that electrically connects the first wiring 2 and the second wiring 4, and a first protective layer 6 that is disposed between the second substrate 3 and the first wiring 2 in the first direction, thereby suppressing breakage of the first wiring 2.

[0032] Moreover, it is preferable that the first protective layer 6 is provided on the first substrate 1, not on the second substrate 3. By providing the first protective layer 6 on the first substrate 1, the first protective layer 6 can be disposed continuously in a portion that does not overlap with the second substrate 3 when viewed from the first direction. This reduces the risk of misalignment due to expansion and contraction. The first protective layer 6 may be provided on the second substrate 3, and disposed between the second substrate 3 and the first wiring 2 in the first direction.

[0033] In addition, the first protective layer 6 is preferably disposed between the second substrate end 31 and the first wiring 2 in the first direction. As described above, the second substrate end 31 includes a corner. The corner is an intersection of the end face and the lower surface. The corner may be a ridge line or a convex curved surface. Because the corner has a large effect on the first wiring 2 when it comes into contact with the first wiring 2 due to its shape, by disposing the first protective layer 6 between the second substrate end 31 and the first wiring 2 in the first direction, breakage of the first wiring 2 can be further suppressed.

[0034] Moreover, in the region where the second base material 3 and the first wiring 2 overlap when viewed from the first direction, it is preferable that the entire first wiring 2 is covered by the connection member 5 or the first protective layer 6. By adopting the above-mentioned configuration, it is possible to further reduce contact between the first wiring 2 and the second base material 3. In addition, there is a risk that moisture will enter from the exposed portion of the first wiring 2, causing ion migration. By adopting the above-mentioned arrangement, it is possible to suppress ion migration.

[0035] It is also preferable to have a connection region 7 where the first wiring 2 and the second wiring 4 overlap when viewed from the first direction. The first wiring 2 and the second wiring 4 are electrically connected in the connection region 7, thereby improving connection reliability.

[0036] The dimensions of the connection region 7 are not particularly limited, but are preferably 0.5 mm or more and 20 mm or less. When the connection region 7 is 0.5 mm or more, the connection area increases and the connection reliability improves. On the other hand, the stretchability of the portion of the stretchable wiring 2 that contacts the connection member is reduced, so that when the connection region is 20 mm or less, the deterioration of the stretchability performance of the stretchable device 100 can be suppressed. In other words, when the connection region is 0.5 μm or more and 20 mm or less, it is possible to provide a stretchable device 100 that has high connection reliability and suppresses the deterioration of the stretchability performance.

[0037] The above-mentioned dimensions of the connection region 7 are the vertical dimensions in FIG. 1A and the horizontal dimensions in FIG. 1B. As shown in FIG. 1A, the connection region 7 has a dimension in the width direction of the first wiring 2 and the second wiring 4. As shown in FIG. 1A, a plurality of connection regions 7 may be provided. Although the connection members 5 are disposed in all of the connection regions 7 in FIG. 1B, it is sufficient that they are disposed in at least a portion of the connection regions 7. As shown in FIG. 1B, there may or may not be a gap between the connection members 5 and the first substrate 3.

[0038] Next, the connection of the stretchable device 100 will be described. When the first substrate 1 and the second substrate 2 are connected, the first substrate 1 and the second substrate 2 may be pressure-bonded, such as by applying pressure. By performing such a process, the connection member 5 is deformed, and the overall thickness changes. That is, the stretchable device 100 can be made low-profile. This tendency is particularly noticeable when the connection member 5 contains a resin. Also, as described above, when the connection member 5 contains conductive particles, if the distance between the first wiring 2 and the second wiring 4 in the first direction is greater than the maximum diameter of the conductive particles, they cannot be electrically connected. In such a case, by performing pressure bonding as described above, the distance between the first wiring 2 and the second wiring 4 in the first direction is reduced. Therefore, the electrical connection between the first wiring 2 and the second wiring 4 can be more reliably performed.

[0039] If the first wiring 2 and the second wiring 4 are electrically connected before the pressure bonding, it is not necessary to apply pressure. If the connection member 5 has adhesiveness, it is not necessary to apply pressure. Furthermore, the pressure bonding method is not particularly limited.

[0040] [First Modification of the First Embodiment] 3 is a cross-sectional view of a stretchable device 101 according to a first modified example of the first embodiment. The stretchable device is different from the stretchable device 100 according to the first embodiment in the arrangement of the second base material 3. Specifically, the second base material 3 and the first protective layer 6 are in contact with each other.

[0041] As described above, the stretchable device 100 may be subjected to a process such as crimping. Fig. 3 shows the structure of the stretchable device 100 after crimping. The thickness of the connection member 5 changes due to the crimping, and the overall height is reduced. In addition, the second base material 3 and the protective layer 6 are in contact with each other.

[0042] As described above, the first protective layer 6 may be in contact with the first base material 3. That is, it is possible to provide a stretchable device 101 that suppresses breakage of the first wiring 2 and achieves a low height.

[0043] In the stretchable device 101, the first wiring 1 and the second base material 3 may be in contact with each other before deformation due to pressure bonding or external force. Similarly, the first wiring 1 and the second base material 3 may not be in contact with each other after pressure bonding.

[0044] [Second Modification of the First Embodiment] Hereinafter, a second modified example of the first embodiment will be described with reference to Fig. 4. Fig. 4 is a partial cross-sectional view of a stretchable device 102 according to the second modified example of the first embodiment. The stretchable device 101 differs from the stretchable device 100 according to the first embodiment in that a connection member 5 and a first protective layer 6 are in contact with each other.

[0045] It is preferable that the connection member 5 and the first protective layer 6 are in contact with each other. By arranging them as described above, the connection member 5 is prevented from being deformed on the first protective layer 6 side. In other words, the connection member 5 can maintain a constant thickness on the first substrate 1 side where the first protective layer 6 is located. Since the first wiring has elasticity, it can be expanded and contracted in the left-right direction in FIG. 4. At this time, it is conceivable that the connection member 5 is further deformed by the expansion and contraction. At this time, if the connection member 5 does not have a sufficient thickness, there is a risk that the connection will be broken by the expansion and contraction. By having the connection member 5 have a constant thickness on the first wiring 3 side in the left-right direction in FIG. 4, it is possible to prevent connection failure caused by positional deviation due to expansion and contraction. In addition, by having a sufficient thickness of the connection member, it is possible to improve the connection reliability.

[0046] Furthermore, if the connecting member 5 contains a resin, there is a possibility that excessive deformation may occur depending on the viscosity of the resin. Since the first protective layer 6 and the connecting member 5 are in contact with each other, the connecting member 5 can be selected without being limited by viscosity. The connecting member 5 is not limited to being disposed as shown in FIG.

[0047] Moreover, it is preferable that at least a portion of the second wiring 4 does not overlap with the connection member 5 in the region where the first base material 1 and the second wiring 4 overlap when viewed from the first direction.

[0048] In other words, the second wiring 4 is exposed from the connection member 5 in the region overlapping with the first base material 1 when viewed from the first direction. With this arrangement, the connection member 5 has room to deform toward the second base material 3, and can therefore deform sufficiently. In other words, the connection reliability can be improved.

[0049] By combining the above two configurations, it is possible to provide a stretchable device 102 with high connection reliability, in which the connection member 5 on the side of the stretchable first wiring 2 maintains a sufficient thickness by suppressing deformation, while leaving room for deformation of the connection member 5 on the side of the second wiring.

[0050] 4, the first protective layer 6 and the connecting member 5 may be in contact with each other before the connecting member 5 is deformed by crimping or the like. With such a configuration, it is possible to further suppress the deformation of the connecting member 5. Note that the first protective layer 6 and the connecting member 5 may be separated from each other before crimping, and may be arranged such that the first protective layer 6 and the connecting member 5 come into contact with each other due to the deformation of the connecting member 5 by crimping.

[0051] As shown in FIG. 4, the connection member 5 may be disposed in a portion other than the connection region, and may be in direct contact with the first base material 1 and the second base material 3.

[0052] 4, when the first protective layer 6 and the second base material 3 are spaced apart in the first direction, there is a possibility that the connecting member 5 may enter between the first protective layer 6 and the second base material 3 due to deformation caused by pressure bonding. In other words, it is possible to leave room for deformation of the connecting member 5 on the upper surface of the first protective layer 6 while ensuring the thickness of the first protective layer 6. Therefore, it is possible to provide a stretchable device 102 with improved connection reliability.

[0053] [Third Modification of the First Embodiment] Hereinafter, a stretchable device 103 according to a third modified example of the first embodiment will be described with reference to Fig. 5. The stretchable device 103 is different from the stretchable device 100 according to the first embodiment in the arrangement of the connection member 5 and the first protective layer 6.

[0054] Fig. 5 is a cross-sectional view showing the stretchable device 103. As shown in Fig. 5, the connection member 5 and the first protective layer 6 may be disposed so as to overlap when viewed from the first direction.

[0055] When the connection member 5 and the first protective layer 6 overlap when viewed from the first direction, the connection member 5 is disposed on the upper surface of the first protective layer 6. The contact area is increased compared to when the connection member 5 is in contact with only the end surface of the first protective layer 6. This can therefore improve the connection reliability.

[0056] That is, it is preferable that the first protective layer 6 and the connection member 5 overlap when viewed from the first direction. In other words, it is preferable that the connection member 5 is disposed on the upper surface 61 of the first protective layer 6. It is also preferable that the conductive member 4 is disposed between the second base material 3 and the first protective layer 6 in the first direction.

[0057] [Fourth Modification of the First Embodiment] Hereinafter, a stretchable device 104 according to a fourth modified example of the first embodiment will be described with reference to Fig. 6. The stretchable device 104 is different from the stretchable device 100 according to the first embodiment in terms of a first protective layer 6.

[0058] As described above, the first protective layer 6 has a first protective layer upper surface 61 closest to the second substrate 3, a first protective layer lower surface 62 closest to the first substrate 1, and a first protective layer end surface 63 connecting the first protective layer upper surface 61 and the first protective layer lower surface 62.

[0059] In a cross-sectional view, it is preferable that the angle formed between the first protective layer end surface 63 and the first protective layer lower surface is an acute angle. In other words, it is preferable that the first protective layer lower surface 62 has a region that does not overlap with the first protective layer upper surface 61 when viewed from the first direction.

[0060] By arranging in this manner, the connection member 5 is easily arranged on the upper surface 61 of the first protective layer when it is deformed by crimping, and the connection reliability can be improved.

[0061] It is also preferable that the lower surface 62 of the first protective layer overlaps the second wiring 4 and the upper surface of the first protective layer does not overlap the second wiring 4 when viewed from the first direction.

[0062] In other words, as shown in FIG. 6, it is preferable that the lower surface 62 of the first protective layer overlaps the connection region 7 and the upper surface 61 of the first protective layer does not overlap the connection region 7 when viewed from the first direction.

[0063] With this arrangement, the resin arranged in the connection region 7 moves along the first protective layer end face 63 to the first protective layer upper face 61, improving the connection reliability. Furthermore, when the connection member 5 is deformed by crimping or the like, the connection member 5 can be moved more efficiently to the first protective layer upper face 61.

[0064] [Fifth Modification of the First Embodiment] Hereinafter, a stretchable device 105 according to a fifth modified example of the first embodiment will be described with reference to Fig. 7. The stretchable device 105 differs from the stretchable device 100 according to the first embodiment in that it includes an insulating layer 9.

[0065] As shown in FIG. 7, it is preferable to provide an insulating layer 9 between the first substrate 1 and the first wiring 2.

[0066] The insulating layer 9 is a resin formed by printing. More specifically, it is preferably a resin material or a mixture of a resin material and an inorganic material. Examples of the resin material include urethane-based, styrene-based, olefin-based, silicone-based, fluorine-based, nitrile rubber, latex rubber, vinyl chloride, ester-based, amide-based, and other elastomer-based resins, epoxy, phenolic, acrylic, polyester, imide-based, rosin, cellulose, polyethylene terephthalate-based, polyethylene naphthalate-based, and polycarbonate-based resins. The insulating layer 9 does not have to be made of a single material. The first protective layer 6 and the insulating layer 9 may be the same member.

[0067] 7, the insulating layer 9 is disposed between the first substrate 1 and the first wiring 2 in the first direction. In other words, it is provided on the first substrate 1 and in contact with the lower surface of the first wiring 2.

[0068] If the first substrate 1 has moisture permeability, moisture may penetrate from the first substrate 1 to the first wiring 2, causing ion migration. By providing the insulating layer 9, it is possible to suppress the penetration of moisture from the first substrate 1 to the first wiring 2. In other words, a stretchable device 105 in which short-circuiting of the first wiring 2 is suppressed is provided.

[0069] The insulating layer 9 may be disposed, for example, so as to cover only the lower surface of the first wiring 2, or may be disposed on a portion of the first substrate 1 where there is no first wiring 2. Similarly, it may be disposed so as to cover the entire first substrate 1. Also, as long as it is in contact with the second wiring 2, a different layer may be disposed between the first substrate 1 and the insulating layer 9.

[0070] [Sixth Modification of the First Embodiment] Hereinafter, a stretchable device 106 according to a sixth modified example of the first embodiment will be described with reference to FIGS. 8A to 8D. The stretchable device 106 is different from the stretchable device 100 according to the first embodiment in that the first protective layer 6 is different.

[0071] FIG. 8A is a partial top view of the stretchable device 105. FIG. 8B is a cross-sectional view taken along line AA in FIG. 8A. FIG. 8C is a cross-sectional view taken along line BB in FIG. 8A. FIG. 8D is an exploded plan view of the stretchable device 106. As shown in FIG. 8A and FIG. 8D, the first protective layer 6 has projections and recesses in the vertical direction of the figure. In FIG. 8B and FIG. 8C, for the sake of convenience, the connection member 5 and the first protective layer 6 are indicated by dotted hatching.

[0072] A part of the first protective layer 6 is disposed in a non-wiring region 8 that does not overlap with the first wiring 2 when viewed from the first direction. When viewed from the first direction, in the non-wiring region 8, the first protective layer 6 preferably has a recess 16 on its end surface. Specifically, the recess 16 opens to the upper surface, lower surface and end surface of the first protective layer 6.

[0073] More specifically, the first base material 1 is composed of a region that overlaps with the first wiring 1 when viewed from the first direction, and a region that does not overlap with the first wiring 1. The region of the first base material 1 that does not overlap with the first wiring 1 when viewed from the first direction is shown as a non-wiring region 8.

[0074] As described above, since the first wiring 2 has elasticity, by disposing the first protective layer 6, it is possible to suppress a decrease in the thickness of the connection member 5 and improve the connection reliability. On the other hand, since the non-wiring region 8 is an area that is less involved in the connection between the first wiring 2 and the second wiring 4, it is an area where it is not necessary to suppress the deformation of the connection member 5. By having the first protective layer 6 in the non-wiring region 8, it is possible to provide a stretchable device 105 with high connection reliability that allows the connection member 5 to deform in the non-wiring region 8 while ensuring the thickness of the connection member 5 in the area where the first wiring 2 and the second wiring 4 are connected.

[0075] 8A and 8D, the recess 16 may be formed in a part of the non-wiring region 8 in the left-right direction in the figure, or the recess 16 may be formed in the entire non-wiring region 8. In other words, in the width direction of the first wiring 2, the length of the recess formed in the non-wiring region 8 may be the same as the length of the non-wiring region 8, or may be shorter.

[0076] The depth of the recess 16 is preferably 50 μm or more. The depth of the recess 16 refers to the maximum length in the extension direction of the wiring in a plan view, and refers to the length in the vertical direction in Fig. 8A. Specifically, it refers to the distance between an end face 63 formed in an adjacent non-wiring region 8 and an end face 63 formed in a region overlapping with the first wiring 2 when viewed from the first direction, and is indicated by a double-headed arrow Y in Fig. 8D.

[0077] Moreover, it is preferable that a part of the first protective layer 6 is disposed in the non-wiring region 8, and that in the non-wiring region 8, the connection member 5 and at least a part of the first protective layer 6 are separated from each other.

[0078] The above configuration will be specifically described with reference to Fig. 8B and Fig. 8C. Fig. 8B is a cross-sectional view of a portion overlapping with the first wiring when viewed from the first direction, i.e., having the connection region 7. Since Fig. 8B is the same cross-sectional view as Fig. 5, the effects and detailed description will be omitted. Note that Fig. 5 is a cross-sectional view of the stretchable device 103 according to the third modified example of the first embodiment, but it goes without saying that the same structure as other embodiments and modified examples may be used.

[0079] Fig. 8C is a cross-sectional view of the non-wiring region 8. When the connection member 5 and the first protective layer 6 are at least partially separated from each other in the non-wiring region 8, as shown in Fig. 8C, the deformation of the connection member 5 is not suppressed. In other words, the connection reliability can be improved.

[0080] [Second embodiment] Hereinafter, a stretchable device 107 according to the second embodiment will be described with reference to Fig. 9. The stretchable device 107 differs from the stretchable device 100 according to the first embodiment in the configuration and arrangement of the first base material 1.

[0081] In the stretchable device 107 according to the second embodiment, the first base material 1 has stretchability. In addition, the Young's modulus of the second wiring 4 is greater than that of the first base material 1.

[0082] When the first base material 1 has elasticity, in addition to the above-mentioned effects, since the Young's modulus of the first base material 1 is low, it may be brought into contact with the second wiring 4. Since the Young's modulus of the first base material 1 is low, it is possible to reduce the possibility of breakage due to contact.

[0083] 9, in the stretchable device 107 according to the second embodiment, the first substrate 1 is in contact with the second wiring 4. Although not shown, in a region of the second substrate 3 where the second wiring 4 is not provided, the first substrate 1 and the second substrate 3 may be in contact with each other.

[0084] 9, the first substrate 1 and the second wiring 4 come into contact with each other, so that the first substrate 1 is disposed between the connection region 7 and a portion of the second substrate 3 that does not overlap with the first wiring 2. The first substrate 1 can prevent moisture from penetrating into the connection region 7, i.e., the first wiring 2.

[0085] That is, it is preferable that the first base material 1 and the second wiring 4 are in contact with each other. With the above configuration, it is possible to suppress the intrusion of moisture and the occurrence of short circuits due to ion migration.

[0086] The arrangement of the first substrate 1 is not limited to that shown in FIG. 9. Specifically, only the end of the first substrate 1 may be in contact with the second wiring 4. The first protective layer 6 may be in contact with the second substrate 3. The contact between the first protective layer 6 and the second substrate 3 can further suppress the intrusion of moisture. In this case, by using a soft material for the first protective layer 6, it can be made to conform to the shape of the second substrate 3.

[0087] 9, it is preferable to provide a gap 15 between the first base material 1 and the connection member 5. The gap 15 provides room for deformation of the connection member 5, thereby further improving the connection reliability.

[0088] It is not necessary that the gap 15 is disposed between the first base material 1 and the connecting member 5. As described above, the first base material 1 has elasticity and is soft, and therefore can follow the deformation of the connecting member 5.

[0089] [First Modification of the Second Embodiment] Hereinafter, a stretchable device 108 according to a first modified example of the second embodiment will be described with reference to Fig. 10. The stretchable device 108 differs from the stretchable device 107 according to the second embodiment in that the stretchable device 108 includes a second protective layer 10.

[0090] The second protective layer 10 is preferably made of a resin material or a mixture of a resin material and an inorganic material, similar to the first protective layer 6. Examples of the resin material include urethane, styrene, olefin, silicone, fluorine, nitrile rubber, latex rubber, vinyl chloride, ester, amide and other elastomer resins, epoxy, phenol, acrylic, polyester, imide, rosin, cellulose, polyethylene terephthalate, polyethylene naphthalate, and polycarbonate resins. The first protective layer 6 and the second protective layer 10 may be made of the same material or different materials.

[0091] Furthermore, it is preferable that a second protective layer 10 is provided to cover the second wiring 4, and that the second protective layer 10 and the first base material 1 overlap in the first direction.

[0092] With the above-mentioned configuration, direct contact between the first base material 1 and the second wiring 4 can be suppressed, and therefore intrusion of moisture into the first wiring 1 can be suppressed.

[0093] It is also preferable that the thickness of the second protective layer 10 is 1 μm or more and 100 μm or less. As shown in Fig. 10, the thickness of the second protective layer 10 and the thickness of the connection region 7 are substantially the same, so that the thickness of the connection region 7 can be adjusted by adjusting the thickness of the second protective layer. Also, short circuits caused by foreign matter and ion migration can be suppressed.

[0094] Furthermore, it is only necessary that the second protective layer 10 and the first substrate 1 overlap in the first direction, and the second protective layer 10 and the first substrate 6 may be in contact with each other or separated from each other.

[0095] It is preferable that the second protective layer 10 and the first substrate 6 are in contact with each other, and that a gap 15 is provided between the second protective layer 10 and the connection member 5 .

[0096] As described above, the gap 15 functions as a space for deformation of the connection member 5. Therefore, the intrusion of moisture into the first wiring 2 can be suppressed, and the connection reliability can be improved.

[0097] The size of the gap is not particularly limited.

[0098] [Second Modification of the Second Embodiment] Hereinafter, a stretchable device 109 according to a second modified example of the second embodiment will be described with reference to Fig. 11. The stretchable device 109 is different from the stretchable device 107 according to the second embodiment in that the stretchable device 109 includes a second protective layer 10.

[0099] As shown in FIG. 11, it is preferable that the second protective layer 10 and the first base material 1 are in contact with each other, and that the first base material 1 and the second wiring 4 are in contact with each other between the second protective layer 10 and the connection member.

[0100] As shown in FIG. 11, the first substrate 1 is in contact with the second protective layer 10 and the second wiring 4. More specifically, the first substrate 1 having elasticity conforms to the gap 15 shown in FIG. 10. As described above, the first substrate 1 conforms to the deformation of the connection member 5, so that a margin for deformation of the connection member 5 is ensured. That is, similar to the stretchable device 108, it is possible to provide a stretchable device 109 that suppresses the intrusion of moisture into the first wiring 1 and has high connection reliability.

[0101] [Third embodiment] Hereinafter, a stretchable device 110 according to the third embodiment will be described with reference to Fig. 12. The stretchable device 110 differs from the stretchable device 100 according to the first embodiment in that the stretchable device 110 includes a third protective layer 12 and a fourth protective layer 13.

[0102] As shown in Figure 12, the first substrate 1 has a third protective layer 12 covering the main surface opposite the first wiring 2, and a fourth protective layer 13 covering the main surface of the second substrate 3 opposite the second wiring 4.

[0103] An example of the third protective layer 12 is a resin material having elasticity. For example, the third protective layer 12 is formed of an ionomer resin, a polyester resin, a styrene resin, an olefin resin, an epoxy resin, a urethane resin, an acrylic resin, or a silicone resin, and is preferably formed of a urethane resin. An example of the urethane resin is thermoplastic polyurethane (TPU). An example of the styrene resin is styrene-butadiene-styrene copolymer resin (SBS). The third protective layer 12 may be composed of a plurality of members.

[0104] An example of the fourth protective layer 13 is a resin material having elasticity. For example, the fourth protective layer 13 is formed of an ionomer resin, a polyester resin, a styrene resin, an olefin resin, an epoxy resin, a urethane resin, an acrylic resin, or a silicone resin, and is preferably formed of a urethane resin. An example of the urethane resin is thermoplastic polyurethane (TPU). An example of the styrene resin is styrene-butadiene-styrene copolymer resin (SBS). The fourth protective layer 13 may be composed of a plurality of members. The third protective layer 12 and the fourth protective layer 13 may be the same member or different members.

[0105] Members containing resin, such as the first protective layer 6, the insulating layer 9, and the second protective layer 10, may have cytotoxicity. By providing the third protective layer 12, it is possible to suppress leakage of cytotoxic components. The same effect can be achieved with the fourth protective layer 13. Furthermore, by providing the third protective layer 12 and the fourth protective layer 13, it is possible to further suppress leakage of cytotoxic components.

[0106] Note that each embodiment and modification is an example, and the present disclosure is not limited to each embodiment and modification. Also, each drawing is an example of components, and does not limit the shape. Also, partial replacement or combination of the configurations shown in different embodiments and modifications is possible. [Explanation of symbols]

[0107] 100~110: Stretchable devices 1: First base material 11: First base material end 2: 1st wiring 3:Second base material 31: Second base material end 4:Second wiring 5: Connection parts 6: 1st protective layer 61:Top surface of first protective layer 62: Lower surface of the first protective layer 63: First protective layer end surface 7: Connection area 8: Non-wiring area 9: Insulating layer 10:Second protective layer 12:Third protective layer 13: 4th protective layer 15:Void 16: Recess X: 1st direction

Claims

1. A first substrate; A first wiring having elasticity provided on the first base material; A second base material facing the first base material in a first direction which is a thickness direction of the first base material; a second wiring provided on the second base material and facing the first wiring in the first direction; a connection member that electrically connects the first wiring and the second wiring; A stretchable device comprising: a first protective layer disposed at least between the second substrate and the first wiring in the first direction; Further, a second protective layer is provided to cover the second wiring, The second protective layer and the first base material overlap each other in the first direction, the second protective layer is in contact with the first substrate, The first substrate and the second wiring are in contact between the second protective layer and the connection member.

2. A first substrate; A first wiring having elasticity provided on the first base material; A second base material facing the first base material in a first direction which is a thickness direction of the first base material; a second wiring provided on the second base material and facing the first wiring in the first direction; a connection member that electrically connects the first wiring and the second wiring; A stretchable device comprising: a first protective layer disposed at least between the second substrate and the first wiring in the first direction; Further, a second protective layer is provided to cover the second wiring, The second protective layer and the first base material overlap each other in the first direction, the second protective layer is in contact with the first substrate, A stretchable device comprising an air gap between the second protective layer and the connecting member.

3. The stretchable device according to claim 1 or 2, wherein the first protective layer covers at least a portion of the first wiring.

4. The stretchable device according to claim 1 or 2, wherein an entire portion of the first wiring that overlaps with the second base material when viewed from the first direction is covered by at least one of the connection member or the first protective layer.

5. The stretchable device according to claim 1 or 2, comprising a connection region where the first wiring and the second wiring overlap when viewed from the first direction.

6. 3. The stretchable device according to claim 1, wherein in a region where the first wiring and the second wiring do not overlap among a region where the first substrate and the second wiring overlap when viewed from the first direction, at least a portion of the second wiring does not overlap with the connecting member.

7. The stretchable device according to claim 1 or 2, wherein the connection member and the first protective layer are in contact with each other.

8. The stretchable device according to claim 1 or 2, wherein the first protective layer and the connection member overlap when viewed from the first direction.

9. the first protective layer has an upper surface closest to the second base material, a lower surface in contact with the first wiring, and an end surface connecting the upper surface and the lower surface, The stretchable device according to claim 1 or 2, wherein, when viewed from the first direction, the lower surface overlaps with the second wiring, and the upper surface does not overlap with the second wiring.

10. a portion of the first protective layer is disposed in a non-wiring region of the first base material that does not overlap with the first wiring when viewed from the first direction; The stretchable device according to claim 1 or 2, wherein in the non-wiring region, the first protective layer has a recess.

11. The stretchable device according to claim 1 or 2, wherein the first protective layer has insulating properties.

12. The stretchable device according to claim 1 or 2, further comprising an insulating layer between the first substrate and the first wiring.

13. The stretchable device according to claim 1 or 2, wherein the first substrate and the second wiring are in contact with each other.

14. The stretchable device according to claim 1 or 2, further comprising a third protective layer covering a main surface of the first substrate opposite the first wiring.

15. The stretchable device according to claim 1 or 2, further comprising a fourth protective layer covering a main surface of the second substrate opposite the second wiring.

16. The stretchable device according to claim 1 or 2, wherein the connecting member comprises a plurality of conductive particles.

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