Stretchable device and method for manufacturing stretchable device

Abstract

This stretchable device has a first stretchable substrate and a second stretchable substrate. One strain gauge is provided with respect to one body portion, and with the body portion as a starting point, extends to a vertical hinge portion or a horizontal hinge portion. The first stretchable substrate and the second stretchable substrate are offset from each other in a planar direction. Some of a plurality of body portions of the first stretchable substrate overlaps with some of a plurality of body portions of the second stretchable substrate, a strain gauge is provided with respect to one out of a vertical hinge portion of the first stretchable substrate and a vertical hinge portion of the second stretchable substrate that overlap in the thickness direction, and a strain gauge is provided with respect to one out of a horizontal hinge portion of the first stretchable substrate and a horizontal hinge portion of the second stretchable substrate that overlap in the thickness direction.

Description

Stretchable device and method for manufacturing stretchable device

[0001] The present invention relates to a stretchable device and a method for manufacturing a stretchable device.

[0002] The stretchable device has a stretchable substrate with excellent elasticity and flexibility. The stretchable substrate includes a resin substrate and an array layer disposed along the resin substrate. The stretchable substrate includes body portions arranged in a matrix and hinge portions connecting the body portions to each other. The hinge portions in Patent Document 1 have multiple arc portions and a meandering shape. When, for example, a tensile load acts on the stretchable substrate, the arc portions of the hinge portions expand. As a result, the body portions connected to both ends of the hinge portion separate from each other, and the stretchable substrate elongates. In addition, there are two types of hinge portions extending from one body portion. One is a vertical hinge portion that extends along the planar direction of the stretchable substrate. The other is a horizontal hinge portion that extends in the planar direction, intersecting the vertical hinge portion.

[0003] JP 2020-202208 A

[0004] Recently, in order to detect the load acting on a stretchable device, studies have been conducted on installing strain gauges in the hinge section to detect the strain (deformation) of the hinge section. However, the width of the hinge section is relatively small, and the number of wires that can be arranged in the hinge section is limited. In other words, it may be difficult in terms of layout to install strain gauges in both the vertical hinge section and the horizontal hinge section connected to one body section. On the other hand, if a strain gauge is installed in only one of the vertical hinge section or the horizontal hinge section connected to one body section, it is not possible to achieve high-precision load detection.

[0005] An object of the present invention is to provide a stretchable device that can achieve high-resolution load detection and a method for manufacturing a stretchable device.

[0006] A stretchable device according to one aspect of the present disclosure includes a first stretchable substrate and a second stretchable substrate arranged in a thickness direction. The first stretchable substrate and the second stretchable substrate are a common stretchable substrate that are common to each other. A plurality of strain gauges are provided on the common stretchable substrate. When viewed from the thickness direction, the common stretchable substrate is divided into a plurality of body portions arranged spaced apart from each other in a planar direction intersecting the thickness direction, and a plurality of hinge portions connecting the body portions. The plurality of hinge portions include vertical hinge portions extending in a first direction parallel to the planar direction, and horizontal hinge portions extending in a second direction parallel to the planar direction and intersecting the first direction. One strain gauge is provided for each body portion, and extends from the body portion as a starting point to the vertical hinge portion or the horizontal hinge portion. The first stretchable substrate and the second stretchable substrate are arranged offset from each other in the planar direction. Some of the body portions of the first stretchable substrate and some of the body portions of the second stretchable substrate overlap in the thickness direction. The strain gauge is provided on one of the vertical hinge portion of the first stretchable substrate and the vertical hinge portion of the second stretchable substrate that overlap in the thickness direction. The strain gauge is provided on one of the horizontal hinge portion of the first stretchable substrate and the horizontal hinge portion of the second stretchable substrate that overlap in the thickness direction.

[0007] FIG. 1 is a perspective view of a stretchable device according to a first embodiment. FIG. 2 is a cross-sectional view schematically illustrating a cross section of the stretchable device according to the first embodiment cut in a second direction, and more specifically, a cross-sectional view schematically illustrating a cross section cut along line II-II in FIG. 4. FIG. 3 is a plan view of a first device according to the first embodiment. FIG. 4 is an enlarged view of a portion of a common stretchable substrate according to the first embodiment. FIG. 5 is an enlarged view of a vertical hinge portion according to the first embodiment. FIG. 6 is an enlarged view of a vertical hinge portion according to the first embodiment when a tensile load in a first direction is applied to the vertical hinge portion according to the first embodiment. FIG. 7 is a schematic diagram illustrating a circuit configuration of a strain detection circuit according to the first embodiment. FIG. 8 is a schematic diagram illustrating strain gauges of a first stretchable substrate and a second stretchable substrate according to the first embodiment when viewed from the thickness direction. FIG. 9 is a flow chart illustrating a method for manufacturing a stretchable device according to a second embodiment. FIG. 10 is a flow chart illustrating a method for manufacturing a stretchable device according to a third embodiment. FIG. 11 is a plan view of two common stretchable substrates bonded in the bonding step of the third embodiment, showing an enlarged view of two hinges arranged in the thickness direction.

[0008] Modes (embodiments) for carrying out the present disclosure will be described in detail with reference to the drawings. The invention of the present disclosure is not limited to the contents described in the following embodiments. Furthermore, the components described below include those that can be easily imagined by a person skilled in the art and those that are substantially identical. Furthermore, the components described below can be combined as appropriate. Note that the disclosure is merely an example, and any appropriate modifications that a person skilled in the art can easily conceive while maintaining the gist of the invention are naturally included within the scope of the present invention. For clarity of explanation, the drawings may schematically depict the width, thickness, shape, etc. of each part compared to the actual embodiment. However, these are merely examples and are not intended to limit the interpretation of the present invention. Furthermore, in this specification and each figure, components similar to those described above with reference to the previous figures are designated by the same reference numerals, and detailed descriptions may be omitted as appropriate.

[0009] Furthermore, in this specification and claims, when expressing an aspect of placing another structure on top of a certain structure, the term "on top" is used, unless otherwise specified, to include both a case in which another structure is placed directly on top of a certain structure so as to be in contact with the certain structure, and a case in which another structure is placed above a certain structure via yet another structure.

[0010] (Embodiment 1) Fig. 1 is a perspective view of a stretchable device according to embodiment 1. As shown in Fig. 1, the stretchable device 100 is formed in a flat plate shape. The stretchable device 100 has a front surface 1 and a back surface 2 (not shown in Fig. 1; see Fig. 2) that face in opposite directions. Hereinafter, the direction parallel to each of the front surface 1 and the back surface 2 will be referred to as the planar direction. Furthermore, the direction in which the front surface 1 and the back surface 2 are arranged will be referred to as the thickness direction.

[0011] The stretchable device 100 is formed into a square (rectangle) in a plan view. The surface 1 of the stretchable device 100 has a pair of first sides 3 and a pair of second sides 4. Hereinafter, the direction parallel to the planar direction and parallel to the first sides 3 will be referred to as the first direction X, and the direction parallel to the second sides 4 will be referred to as the second direction Y.

[0012] In a plan view, the stretchable device 100 is divided into a detection area 5 and a non-detection area 6 other than the detection area 5. The detection area 5 is an area that detects a load input to the stretchable device 100. The detection area 5 in this embodiment is located in the center of the stretchable device 100 and is formed in a rectangular shape in a plan view. The non-detection area 6 is formed in a rectangular frame shape in a plan view, and the detection area 5 is located inside it. Note that a boundary line L1 is drawn in FIG. 1 to make the boundary between the detection area 5 and the non-detection area 6 easier to understand.

[0013] FIG. 2 is a cross-sectional view schematically illustrating a cross section of the stretchable device of embodiment 1 taken in the second direction, and more specifically, a cross-sectional view schematically illustrating a cross section taken along line II-II in FIG. 4. As shown in FIG. 2, the stretchable device 100 includes a first layer device 110 and a second layer device 120 stacked in the thickness direction. An adhesive layer 130 is provided between the first layer device 110 and the second layer device 120. Thus, the first layer device 110 and the second layer device 120 are adhered to each other and integrated. Hereinafter, the thickness direction in which the first layer device 110 is disposed as viewed from the second layer device 120 will be referred to as a first thickness direction Z1, and the opposite direction will be referred to as a second thickness direction Z2.

[0014] The first layer device 110 includes a first stretchable substrate 111 and a first elastic resin 112. The second layer device 120 includes a second stretchable substrate 121 and a second elastic resin 122.

[0015] The first elastic resin 112 covers the first stretchable substrate 111. The second elastic resin 122 covers the second stretchable substrate 121. The first elastic resin 112 and the second elastic resin 122 have insulating properties, elasticity, and flexibility. Examples of resins used as the first elastic resin 112 and the second elastic resin 122 include acrylic elastomers. Note that the elastic resin of the present disclosure is not limited to acrylic elastomers, and may be acrylic resin, epoxy resin, urethane resin, or the like, and is not particularly limited.

[0016] A common stretchable substrate is used for the first stretchable substrate 111 and the second stretchable substrate 121. Hereinafter, the stretchable substrate used as the first stretchable substrate 111 or the second stretchable substrate 121 will be referred to as a common stretchable substrate 10.

[0017] 2 , the common stretchable substrate 10 (first stretchable substrate 111) of the first layer device 110 and the common stretchable substrate 10 (second stretchable substrate 121) of the second layer device 120 are offset from each other in the planar direction. Therefore, the difference between the first layer device 110 and the second layer device 120 is the position where the common stretchable substrate 10 is arranged. Therefore, the first layer device 110 and the second layer device 120 will be described using the first layer device 110 as a representative example, and a description of the second layer device 120 will be omitted. After that, the positional relationship between the first stretchable substrate 111 and the second stretchable substrate 121 will be described.

[0018] FIG. 3 is a plan view of the first device of the first embodiment. The first layer device 110 is divided into a first detection region 115 and a first non-detection region 116 other than the first detection region 115 in a plan view. The first detection region 115 is a region that detects a load in a first direction X or a load in a second direction Y input to the first layer device 110. The first detection region 115 is located in the center of the first layer device 110 and is formed in a rectangular shape in a plan view. The first non-detection region 116 is formed in a rectangular frame shape in a plan view, and the first detection region 115 is located inside it. Note that a boundary line L2 is drawn in FIG. 3 to clearly indicate the boundary between the first detection region 115 and the first non-detection region 116. The detection region of the second layer device 120 is referred to as a second detection region 215 (see FIG. 2).

[0019] Fig. 4 is an enlarged view of a portion of the common stretchable substrate of embodiment 1. As shown in Fig. 4, a plurality of lightening holes 19 are provided in the common stretchable substrate 10. As shown in Fig. 2, the lightening holes 19 penetrate the common stretchable substrate 10 in the thickness direction. The lightening holes 19 of the common stretchable substrate 10 are filled with a first stretchable resin 112. Note that, although the lightening holes 19 of this embodiment are filled with the first stretchable resin 112, in the present disclosure, the lightening holes 19 may be left empty and empty.

[0020] As shown in FIG. 4, in plan view, the common stretchable substrate 10 is divided into a plurality of body portions 11 and a plurality of hinge portions 12 that extend in a serpentine manner in the planar direction.

[0021] The body portion 11 has an octagonal shape in a plan view. The body portions 11 are arranged in the first direction X and the second direction Y and are spaced apart from one another. Note that the shape of the body portion 11 in a plan view according to the present disclosure is not limited to an octagonal shape, and may be a circle or another polygonal shape.

[0022] The hinge portion 12 connects adjacent body portions 11. There are two types of hinge portions 12: a vertical hinge portion 12A extending in the first direction X, and a horizontal hinge portion 12B extending in the second direction Y.

[0023] Next, details of the hinge portion 12 will be described. Note that when the horizontal hinge portion 12B is rotated 90 degrees, it has the same shape as the vertical hinge portion 12A. Therefore, in the following, the vertical hinge portion 12A will be described as a representative example, and a description of the horizontal hinge portion 12B will be omitted.

[0024] Fig. 5 is an enlarged view of the vertical hinge portion of the first embodiment. As shown in Fig. 5, the vertical hinge portion 12A has four bent portions 13 and extends in a meandering manner in the first direction X. Each bent portion 13 of this embodiment has an arc shape. Note that the bent portions of the present disclosure may be formed in an angular shape instead of an arc shape. The number of bent portions is not limited to four.

[0025] The four bent portions 13 are a first arc portion 14, a second arc portion 15, a third arc portion 16, and a fourth arc portion 17, which are arranged in this order in the first direction X. The first arc portion 14 and the fourth arc portion 17 are quadrant-shaped and bent at 90 degrees. The second arc portion 15 and the third arc portion 16 are semicircular-shaped and bent at 180 degrees.

[0026] Fig. 6 is an enlarged view of the vertical hinge portion of the first embodiment when a tensile load in a first direction acts on the vertical hinge portion. As shown in Fig. 6, when a tensile load in the first direction X (see arrow W in Fig. 5) acts on the vertical hinge portion 12A, the first arc portion 14, the second arc portion 15, the third arc portion 16, and the fourth arc portion 17 are deformed so that their curvatures become smaller. As a result, the distance from one end to the other end of the vertical hinge portion 12A increases, and the body portions 11 are separated from each other.

[0027] Furthermore, although not shown, when a compressive load in the first direction X acts on the vertical hinge portion 12A, the first arc portion 14, the second arc portion 15, the third arc portion 16, and the fourth arc portion 17 are deformed so as to increase their curvatures, respectively, and as a result, the distance from one end to the other end of the vertical hinge portion 12A decreases, and the body portions 11 move closer to each other.

[0028] 2, the common stretchable substrate 10 has a resin base material 20 and an array layer 21. The resin base material 20 is a base material for manufacturing the array layer 21, and has stretchability, flexibility, and insulating properties. The resin base material 20 is made of a resin material such as polyimide.

[0029] The array layer 21 is provided on a surface of the resin base material 20 in the first thickness direction Z1. The array layer 21 has a plurality of insulating layers (not shown) stacked in the thickness direction, and an electric circuit (strain detection circuit) whose insulation from the outside is ensured by the plurality of insulating layers. Next, the strain detection circuit included in the array layer 21 will be described in detail.

[0030] Fig. 7 is a schematic diagram showing the circuit configuration of the strain detection circuit of embodiment 1. As shown in Fig. 7, the array layer 21 includes strain gauges 30, gate lines 40, signal lines 41, current supply lines 42, transistors 43, connection parts 50 (see Fig. 3), a gate line driving circuit 51 (see Fig. 3), a signal line selection circuit 52 (see Fig. 3), and reference current wiring 53 (see Fig. 3).

[0031] The strain gauge 30 is a detection element that expands in response to strain generated in the hinge portion 12, increasing or decreasing its resistance value. As shown in Fig. 5, the strain gauge 30 has a first strain gauge 31, a second strain gauge 32, and a folded portion 33. The first strain gauge 31 and the second strain gauge 32 extend along the hinge portion 12. The folded portion 33 connects the ends of the first strain gauge 31 and the second strain gauge 32 to each other.

[0032] The start end 34 and end end 35 of the strain gauge 30 are disposed in the body portion 11. As described above, the strain gauge 30 of the embodiment extends from the body portion 11 to the hinge portion 12, then turns back and returns to the body portion 11a. Therefore, the strain gauge 30 of the present embodiment has two strain gauges (a first strain gauge 31 and a second strain gauge 32). Note that the present disclosure may be configured with a single strain gauge.

[0033] 7, one strain gauge 30 is provided for each body portion 11. In other words, the strain gauge 30 does not extend to both the vertical hinge portion 12A and the horizontal hinge portion 12B connected to one body portion 11. Hereinafter, the strain gauge 30 disposed in the vertical hinge portion 12A will be referred to as the vertical strain gauge 30A, and the strain gauge 30 disposed in the horizontal hinge portion 12B will be referred to as the horizontal strain gauge 30B.

[0034] 4, the plurality of body parts 11 arranged in the first direction X are provided with alternating vertical strain gauges 30A and horizontal strain gauges 30B. The plurality of body parts 11 arranged in the second direction Y are provided with alternating vertical strain gauges 30A and horizontal strain gauges 30B.

[0035] As shown in FIG. 7 , the gate line 40 is disposed across the horizontal hinge portions 12B and the body portions 11, and extends in the second direction Y. A plurality of gate lines 40 are provided in the second direction Y. A signal line 41 and a current supply line 42 are disposed across the vertical hinge portions 12A and the body portions 11, and extend in the first direction X. Although not specifically shown in FIG. 3 , a plurality of signal lines 41 and a plurality of current supply lines 42 are provided in the second direction Y. The end 35 of the strain gauge 30 is connected to the signal line 41. The current supply line 42 is connected to a reference current wiring 53 (see FIG. 3 ), and a predetermined amount of current is supplied thereto.

[0036] The transistor 43 is a switching element and is disposed in each body portion. The gate electrode of the transistor 43 is connected to the gate line 40. The drain electrode of the transistor 43 is connected to the current supply line 42. The source electrode of the transistor 43 is connected to the beginning 34 of the strain gauge 30.

[0037] 3, the connection portion 50, the gate line driving circuit 51, the signal line selection circuit 52, and the reference current wiring 53 are arranged so as to overlap the first non-detection region 116. The connection portion 50 is for connecting to a driving IC (Integrated Circuit) arranged outside the stretchable device 100.

[0038] The gate line driving circuit 51 drives the multiple gate lines 40 based on various control signals from the driving IC. The gate line driving circuit 51 sequentially or simultaneously selects the multiple gate lines 40 and supplies gate driving signals to the selected gate lines 40. The signal line selection circuit 52 is a switch circuit that sequentially or simultaneously selects the multiple signal lines 41. The signal line selection circuit 52 is, for example, a multiplexer. The signal line selection circuit 52 connects the selected signal line 41 to the driving IC based on a selection signal supplied from the driving IC. The reference current wiring 53 is wiring for supplying a predetermined amount of current to the current supply line 42 and extends along the first non-detection region 116. The reference current wiring 53 is connected to the driving IC via a connection portion 50, and a predetermined amount of current flows through the reference current wiring 53.

[0039] 7, in the strain detection circuit described above, when a gate line 40 is selected by the gate line driving circuit 51 and scanned, the transistor 43 turns ON. As a result, the current supply line 42 and the starting end 34 of the strain gauge 30 are electrically connected, and a predetermined amount of current flows through the strain gauge 30. Thereafter, a current (electrical signal) is input to the signal line 41 connected to the ending end 35 of the strain gauge 30. The current (electrical signal) input to the signal line 41 is then sent to the driving IC.

[0040] Here, if the hinge portion 12 is deformed (if strain occurs in the strain gauge 30), the resistance value of the strain gauge 30 changes. In other words, the current value input to the signal line 41 differs depending on whether strain occurs in the strain gauge 30 or not. Therefore, the driving IC detects the amount of strain in the strain gauge 30 from the amount of change in the current value.

[0041] Next, the positional relationship between the common stretchable substrate 10 (first stretchable substrate 111) of the first layer device 110 and the common stretchable substrate 10 (second stretchable substrate 121) of the second layer device 120 will be described.

[0042] 2, the first stretchable substrate 111 and the second stretchable substrate 121 are arranged so as to be offset from each other in the second direction Y. Therefore, the first detection area 115 and the second detection area 215 are offset from each other in the second direction Y. Furthermore, the detection area 5 of the stretchable device 100 is the range where the first detection area and the second detection area 215 overlap each other in the thickness direction. Therefore, the driving IC detects the amount of strain from the detection signals sent from the strain gauges included in the detection area 5, out of the detection signals sent from the first layer device 110 and the second layer device 120.

[0043] 2 , the planar length M of one body portion 11 and one hinge portion 12 is defined as one pitch. In the present disclosure, the planar misalignment between the first stretchable substrate 111 and the second stretchable substrate 121 is in units of one pitch. In other words, the body portion 11 of the first stretchable substrate 111 and the body portion 11 of the second stretchable substrate 121 included in the detection area 5 overlap each other in the thickness direction. Furthermore, the hinge portion 12 of the first stretchable substrate 111 and the hinge portion 12 of the second stretchable substrate 121 included in the detection area 5 overlap each other in the thickness direction. If the body portion 11 of the first stretchable substrate 111 overlaps the hinge portion 12 of the second stretchable substrate 121 in the thickness direction, the body portion 11 of the first stretchable substrate 111 will prevent the hinge portion 12 of the second stretchable substrate 121 from deforming (or will damage the body portion 11). Therefore, in the present disclosure, the misalignment in the planar direction between the first stretchable substrate 111 and the second stretchable substrate 121 is set to one pitch increments, thereby facilitating the deformation of the hinge portion 12 (preventing damage to the body portion 11).

[0044] 8 is a schematic diagram of the strain gauges of the first stretchable substrate 111 and the second stretchable substrate 121 as viewed from the thickness direction in accordance with the first embodiment. In FIG. 8 , the strain gauges 30 of the second stretchable substrate 121 are represented by a single line to distinguish them from the strain gauges 30 of the first stretchable substrate 111. In this embodiment, the misalignment between the first stretchable substrate 111 and the second stretchable substrate 121 in the planar direction (second direction Y) is one pitch. Therefore, as shown in FIG. 8 , a vertical strain gauge 30A is provided on one of the vertical hinge portions 12A of the first stretchable substrate 111 and the second stretchable substrate 121, which overlap in the thickness direction. Further, a horizontal strain gauge 30B is provided on either the horizontal hinge portion 12B of the first stretchable substrate 111 or the horizontal hinge portion 12B of the second stretchable substrate 121, which overlap in the thickness direction.

[0045] From the above, according to this embodiment, the first stretchable substrate 111 and the second stretchable substrate 121 can detect the load acting in the first direction X and the load acting in the second direction acting between each body portion 11, thereby achieving high-resolution load detection.

[0046] The stretchable device 100 of embodiment 1 has been described above, but the present disclosure is not limited to the example shown in embodiment 1. For example, in the stretchable device 100 of embodiment 1, the first stretchable substrate 111 and the second stretchable substrate 121 are each covered with stretchable resin (first stretchable resin 112, second stretchable resin 122), but the first stretchable substrate 111 and the second stretchable substrate 121 may be integrated and covered with stretchable resin (see S6 in FIG. 9 or S15 in FIG. 10 ). Next, a method for manufacturing the stretchable device 100 in which the integrated first stretchable substrate 111 and second stretchable substrate 121 are covered with stretchable resin will be described.

[0047] 9 is a flow diagram showing a manufacturing method of a stretchable device of embodiment 2. The manufacturing method of a stretchable device 100A of embodiment 2 includes an array layer forming step S1, an adhesion step S2, a first lift-off step S3, a lightening hole forming step S4, a second lift-off step S5, and an elastic resin integrating step S6. Note that, with respect to the thickness direction, the upper side of the paper surface of FIG. 9 will be described as a first thickness direction Z1, and the lower side will be described as a second thickness direction Z2.

[0048] The array layer forming step S1 is a step of forming a resin layer (resin substrate 20) and an array layer 21 in this order in the first thickness direction Z1 of the glass plate 300. At this stage, the lightening holes 19 have not been formed in the resin layer (resin substrate 20) and the array layer 21. In other words, what is formed on the glass plate 300 is an intermediate product 400 of the common stretchable substrate 10.

[0049] Although not specifically shown, in the array layer forming step S1, two glass plates 300 are prepared, and an intermediate product 400 for the first stretchable substrate 111A and an intermediate product 400 for the second stretchable substrate 121A are manufactured.

[0050] In the bonding step S2, an adhesive film 410 is bonded to one of the two intermediate products 400 in the first thickness direction Z1. Then, the other intermediate product 400 and the glass plate 300 are turned over and placed on the adhesive film 410. As a result, the two intermediate products 400 are bonded together.

[0051] The two intermediate products 400 are bonded together with a mutual offset in the planar direction. The two intermediate products 400 are offset in the planar direction by one pitch so that the body portions 11 overlap each other. In this embodiment, the two intermediate products 400 are offset by one pitch. Hereinafter, the two integrated intermediate products 400 will be referred to as a second intermediate product 401.

[0052] In the first lift-off process S3, a laser is irradiated from the first thickness direction Z1 onto the glass plate 300 arranged in the first thickness direction Z1 of the second intermediate product 401. This modifies the surface of the resin substrate 20 bonded to the glass plate 300 in the first thickness direction Z1, making it easier to peel the glass plate 300. Then, after the laser irradiation, the resin substrate 20 is peeled off from the glass plate 300.

[0053] In the lightening hole forming process S4, a mask 450 is placed in the first thickness direction Z1 of the second intermediate product 401. Holes (not shown) are formed in the mask. Next, a laser is irradiated from the first thickness direction Z1 of the mask 450 to form lightening holes 19 in the second intermediate product 401. This forms lightening holes 19 in each of the two intermediate products 400. As a result, an integrated first stretchable substrate 111A and a second stretchable substrate 121A are manufactured. Furthermore, the resin base material 20 constituting the first stretchable substrate 111A, the array layer 21 constituting the first stretchable substrate 111A, the adhesive layer, the array layer constituting the second stretchable substrate 121A, and the resin base material 20 constituting the second stretchable substrate 121A are layered in this order in the thickness direction. Furthermore, although not specifically shown, when viewed from the thickness direction, the hinge portion 12 of the first stretchable substrate 111A and the hinge portion 12 of the second stretchable substrate 121A have the same shape.

[0054] In the second lift-off process S5, a laser is irradiated from the second thickness direction Z2 onto the glass plate 300 arranged in the second thickness direction Z2 of the first stretchable substrate 111A. After the laser irradiation, the glass plate 300 is peeled off from the resin base material 20 of the first stretchable substrate 111A.

[0055] The stretchable resin integration step S6 is a step of covering the integrated first stretchable substrate 111A and second stretchable substrate 121A with stretchable resin. In this embodiment, the stretchable resin sandwiches the integrated first stretchable substrate 111A and second stretchable substrate 121A between a lower stretchable resin 131 and an upper stretchable resin 132. When the stretchable resin integration step S6 is completed, the stretchable device 100A is completed.

[0056] 10 is a flow diagram showing a manufacturing method of a stretchable device of embodiment 3. The manufacturing method of a stretchable device 100B of embodiment 3 includes a common stretchable substrate manufacturing process S11, a bonding process S12, a first lift-off process S13, a second lift-off process S14, and an elastic resin integration process S15. Note that, with respect to the thickness direction, the upper side of the paper of FIG. 10 will be described as a first thickness direction Z1, and the lower side will be described as a second thickness direction Z2.

[0057] The common stretchable substrate manufacturing process S11 is a process for manufacturing the common stretchable substrate 10. The lightening holes 19 in the common stretchable substrate 10 are formed by etching. Therefore, while a laser is used in the lightening hole forming process S4 in the second embodiment, a laser is not required according to the third embodiment. Furthermore, two common stretchable substrates 10 are manufactured in the common stretchable substrate manufacturing process S11. Thus, a first stretchable substrate 111B and a second stretchable substrate 121B are manufactured by this process.

[0058] In the bonding step S12, an adhesive film 410 is provided in the first thickness direction Z1 of the first stretchable substrate 111B. Then, the second stretchable substrate 121B and the glass plate 300 are flipped over and placed on the adhesive film 420. This integrates the first stretchable substrate 111B and the second stretchable substrate 121B. The integrated structure is layered in the thickness direction in the following order: the resin base material 20 constituting the first stretchable substrate 111B, the array layer 21 constituting the first stretchable substrate 111B, the adhesive film 410, the array layer 21 constituting the second stretchable substrate 121B, and the resin base material 20 constituting the second stretchable substrate 121B. Furthermore, in this step, the first stretchable substrate 111B and the second stretchable substrate 121B are bonded while being offset from each other in the planar direction. In this embodiment, the offset is one pitch.

[0059] FIG. 11 is a plan view of two common stretchable substrates bonded in the bonding process of embodiment 3, showing an enlarged view of two hinges arranged in the thickness direction. Note that one of the two hinge portions 12 is illustrated by a dashed line. According to the bonding process S12 described above, in plan view, as shown in FIG. 11, the hinge portion 12 of the first stretchable substrate 111B has a shape that is an inverted version of the hinge portion 12 of the second stretchable substrate 121B. In other words, the two hinge portions 12 that overlap in the thickness direction do not have the same shape in plan view. Therefore, one hinge portion 12 does not completely cover the other hinge portion 12.

[0060] Furthermore, in this process, the adhesive film 410 is provided only on the body portion 11, not on the entire first stretchable substrate 111B. In this embodiment, the first stretchable substrate 111B and the second stretchable substrate 121B are bonded to each other only at the body portion 11. This allows the two hinge portions 12 that overlap in the thickness direction to expand and contract independently, reducing strain that occurs in the hinge portions 12.

[0061] 10 , in the first lift-off process S13, a laser is irradiated from the first thickness direction Z1 onto the glass plate 300 arranged in the first thickness direction Z1 of the second stretchable substrate 121B. This modifies the surface of the resin base material 20 of the second stretchable substrate 121B in the first thickness direction Z1, making the glass plate 300 easier to peel. After the laser irradiation, the glass plate 300 is peeled off from the resin base material 20.

[0062] In the second lift-off process S14, a laser is irradiated from the second thickness direction Z2 onto the glass plate 300 arranged in the second thickness direction Z2 of the first stretchable substrate 111B. This modifies the surface of the resin base material 20 of the first stretchable substrate 111 in the second thickness direction Z2, making it easier to peel the glass plate 300. After the laser irradiation, the glass plate 300 is peeled off from the resin base material 20.

[0063] The stretchable resin integration step S15 is a step of covering the integrated first stretchable substrate 111B and second stretchable substrate 121B with stretchable resin. Specifically, the integrated first stretchable substrate 111B and second stretchable substrate 121B are sandwiched between lower stretchable resin 131 and upper stretchable resin 132. When the stretchable resin integration step S6 is completed, the stretchable device 100B is completed.

[0064] The above describes each embodiment. In each embodiment, the first stretchable substrate 111 and the second stretchable substrate 121 are misaligned in the second direction Y. However, in the present disclosure, the misalignment may be in the first direction X or an oblique direction. Furthermore, the misalignment in the planar direction may be a multiple-pitch misalignment as long as it is in one-pitch increments. In other words, it is sufficient that the body portion 11 of the first stretchable substrate 111 and the body portion 11 of the second stretchable substrate 121 overlap in the thickness direction. However, as shown in embodiment 1, a one-pitch misalignment in the planar direction increases the overlapping range (detection region 5) between the first detection region 115 of the first stretchable substrate 111 and the second detection region 125 of the second stretchable substrate 121, which is preferable.

[0065] In addition, although the vertical strain gauges 30A and the horizontal strain gauges 30B are arranged alternately in the first direction X and the second direction Y in the first embodiment, a plurality of (e.g., two) vertical strain gauges 30A may be arranged first, and then a plurality of (e.g., two) horizontal strain gauges 30B may be arranged. Furthermore, the vertical strain gauges 30A and the horizontal strain gauges 30B do not have to be arranged regularly, such as one or two in the first direction X and two in the second direction Y. In other words, the present invention only requires that a strain gauge 30 be provided in either the vertical hinge portion 12A of the first stretchable substrate 111 or the vertical hinge portion 12A of the second stretchable substrate 121, which are overlapping in the thickness direction, and that a strain gauge 30 be provided in either the horizontal hinge portion 12B of the first stretchable substrate 111 or the horizontal hinge portion 12B of the second stretchable substrate 121.

[0066] DESCRIPTION OF SYMBOLS 5 Detection area 6 Non-detection area 10 Common stretchable substrate 11 Body portion 12 Hinge portion 12A Vertical hinge portion 12B Horizontal hinge portion 13 Bending portion 19 Lightening hole 20 Resin substrate 21 Array layer 30 Strain gauge 30A Vertical strain gauge 30B Horizontal strain gauge 100, 100A, 100B Stretchable device 110 First layer device 111, 111A, 111B First stretchable substrate 112 First stretchable resin 115 First detection area 116 First non-detection area 120 Second layer device 121, 121A, 121B Second stretchable substrate 122 Second stretchable resin 130 Adhesive layer 215 Second detection area 300 Glass plate 400 Intermediate product 401 Second intermediate product 410, 420 Adhesive film

Claims

1. A stretchable device comprising a first stretchable substrate and a second stretchable substrate arranged in a thickness direction, the first stretchable substrate and the second stretchable substrate being a common stretchable substrate that is common to each other, the common stretchable substrate being provided with a plurality of strain gauges, the common stretchable substrate being divided into a plurality of body portions arranged at a distance from each other in a planar direction that intersects with the thickness direction when viewed from the thickness direction, and a plurality of hinge portions connecting the body portions, the plurality of hinge portions having vertical hinge portions extending in a first direction parallel to the planar direction, and horizontal hinge portions extending in a second direction that is parallel to the planar direction and intersects with the first direction, one strain gauge being provided for each body portion, and extending from the body portion as a starting point to the vertical hinge portion or the horizontal hinge portion, the first stretchable substrate and the second stretchable substrate being arranged so as to be offset from each other in the planar direction, a stretchable device in which some of the body portions of the first stretchable substrate and some of the body portions of the second stretchable substrate overlap in the thickness direction, the strain gauge is provided on one of the vertical hinge portion of the first stretchable substrate and the vertical hinge portion of the second stretchable substrate that overlap in the thickness direction, and the strain gauge is provided on one of the horizontal hinge portion of the first stretchable substrate and the horizontal hinge portion of the second stretchable substrate that overlap in the thickness direction.

2. The stretchable device of claim 1, wherein the strain gauge extending from the body portion to the vertical hinge portion is a vertical strain gauge, and the strain gauge extending from the body portion to the horizontal hinge portion is a horizontal strain gauge, the plurality of body portions arranged in the first direction are provided with the vertical strain gauges and the horizontal strain gauges alternately, and the plurality of body portions arranged in the second direction are provided with the vertical strain gauges and the horizontal strain gauges alternately, the distance between adjacent body portions in the first direction or the second direction is one pitch, and the first stretchable substrate and the second stretchable substrate are arranged with a one-pitch offset in the first direction or the second direction.

3. A stretchable device as described in claim 1 or claim 2, comprising: a first stretchable resin covering the first stretchable substrate; a second stretchable resin covering the second stretchable substrate; and an adhesive layer disposed between the first stretchable resin and the second stretchable resin and adhering the first stretchable resin and the second stretchable resin together.

4. A stretchable device as described in claim 1 or claim 2, comprising: an adhesive layer disposed between the first stretchable substrate and the second stretchable substrate, bonding the first stretchable substrate and the second stretchable substrate together; and an elastic resin covering the first stretchable substrate and the second stretchable substrate integrated by the adhesive layer.

5. The stretchable device according to claim 4, wherein the common stretchable substrate is composed of a resin base material and an array layer stacked in the thickness direction, and wherein the resin base material constituting the first stretchable substrate, the array layer constituting the first stretchable substrate, the adhesive layer, the array layer constituting the second stretchable substrate, and the resin base material constituting the second stretchable substrate are stacked in this order in the thickness direction, and wherein the hinge portion of the first stretchable substrate and the hinge portion of the second stretchable substrate have the same shape when viewed in the thickness direction.

6. The stretchable device according to claim 4, wherein the common stretchable substrate is composed of a resin base material and an array layer stacked in the thickness direction, and is laminated in the thickness direction in the following order: the resin base material constituting the first stretchable substrate, the array layer constituting the first stretchable substrate, the adhesive layer, the array layer constituting the second stretchable substrate, and the resin base material constituting the second stretchable substrate, and when viewed in the thickness direction, the hinge portion of the second stretchable substrate has a shape that is an inverted shape of the hinge portion of the first stretchable substrate.

7. A method for manufacturing a stretchable substrate, comprising a bonding step of bonding a first stretchable substrate and a second stretchable substrate, wherein the first stretchable substrate and the second stretchable substrate are a common stretchable substrate that are common to each other, and the common stretchable substrate has a plurality of strain gauges, and when viewed from the thickness direction, the common stretchable substrate is divided into a plurality of body portions arranged at a distance from each other in a planar direction intersecting the thickness direction, and a plurality of hinge portions connecting the body portions, and the plurality of hinge portions have vertical hinge portions extending in a first direction parallel to the planar direction, and horizontal hinge portions extending in a second direction parallel to the planar direction and intersecting the first direction, and one strain gauge is provided for each body portion, and extends from the body portion as a starting point to the vertical hinge portion or the horizontal hinge portion, and the bonding step comprises: A method for manufacturing a stretchable device, comprising overlapping and bonding the first stretchable substrate and the second stretchable substrate with a shift in the planar direction so that some of the body portions of the first stretchable substrate and some of the body portions of the second stretchable substrate overlap each other in the thickness direction, and so that the strain gauge is provided on either the vertical hinge portion of the first stretchable substrate or the vertical hinge portion of the second stretchable substrate that overlap in the thickness direction, and so that the strain gauge is provided on either the horizontal hinge portion of the first stretchable substrate or the horizontal hinge portion of the second stretchable substrate that overlap in the thickness direction.

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