Stretchable device

Abstract

To provide a stretchable device in which a crack hardly occurs in an inner peripheral side of an array layer for a circular arc part.SOLUTION: A stretchable device comprises a stretchable device substrate having a resin base material and an array layer that are laminated sequentially. The resin base material includes: a plurality of body parts that is separated from each other in a plane direction crossed to a lamination direction where the resin base material and the array layer are laminated, and is arranged; and a plurality of hinges that is extended while being meandered in the plane direction, and connects both of body parts. Each hinge includes a circular arc-like arc part in view of the lamination direction. A part of the array layer to be laminated to each hinge is an array layer for a hinge. In the array layer for the hinge, a part where it is laminated to the arc part is an array layer for a circular arc-like arc part. A size of a width from an inner peripheral edge to an outer peripheral edge of the array layer for the arc part is smaller than the with from the inner peripheral edge to the outer peripheral edge of the arc part. The inner peripheral edge of the array layer for the arc part is separately arranged to the outer peripheral edge of the arc part from the inner peripheral edge part of the arc part.SELECTED DRAWING: Figure 8

Description

Technical Field

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

Background Art

[0002] A stretchable device has a stretchable substrate that is excellent in stretchability and flexibility. As shown in Patent Document 1, the stretchable substrate has an array layer including an electric circuit and a resin substrate serving as a base material of the array layer. The resin substrate has a body portion arranged in a matrix shape and a hinge connecting the body portions. The hinge has a plurality of arc portions and has a meander shape. When a tensile load acts on the stretchable device, the arc portions of the hinge expand. As a result, the body portions are separated from each other, and the stretchable device extends. Further, when the arc portions are deformed, tensile strain occurs on the inner peripheral side of the arc portions, and compressive strain occurs on the outer peripheral side of the arc portions.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, the array layer has a plurality of insulating layers. These plurality of insulating layers are also laminated on the arc portions of the hinge. Hereinafter, the portion of the array layer (plurality of insulating layers) laminated on the arc portions is referred to as an array layer for arc portions. The insulating layer has a smaller elongation than the resin substrate. Therefore, when a large tensile load acts on the array layer, cracks are likely to occur on the inner peripheral side of the array layer for arc portions.

[0005] An object of the present invention is to provide a stretchable device in which cracks are less likely to occur on the inner peripheral side of an array layer for an arc portion.

Means for Solving the Problems

[0006] A stretchable device according to one aspect of the present disclosure includes a stretchable substrate having a resin base material and an array layer laminated in order. The resin base material has a plurality of body portions arranged apart from each other in a plane direction intersecting a lamination direction in which the resin base material and the array layer are laminated, and a plurality of hinges extending while meandering in the plane direction and connecting the body portions. The hinge has an arc-shaped arc portion when viewed from the lamination direction. Among the array layers, a portion laminated on the hinge is a hinge array layer. Among the hinge array layers, a portion laminated on the arc portion is an arc-shaped array layer for an arc portion. The width of the array layer for the arc portion from the inner peripheral edge to the outer peripheral edge is smaller than the width of the arc portion from the inner peripheral edge to the outer peripheral edge. The inner peripheral edge of the array layer for the arc portion is arranged apart from the inner peripheral edge of the arc portion toward the outer peripheral edge of the arc portion.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

MODE FOR CARRYING OUT THE INVENTION

[0008] 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 by the content described in the following embodiments. Further, the constituent elements described below include those that can be easily assumed by those skilled in the art and substantially the same ones. Furthermore, the constituent elements described below can be combined as appropriate. Note that the disclosure is merely an example, and those that can be easily conceived by those skilled in the art with appropriate modifications while maintaining the gist of the invention are naturally included in the scope of the present invention. The drawings may schematically represent the width, thickness, shape, etc. of each part compared to the actual aspect for clearer explanation, but this is merely an example and does not limit the interpretation of the present invention. Also, in this specification and each figure, the same reference numerals are given to the same constituent elements as those described above with respect to the already shown figures, and detailed description may be omitted as appropriate.

[0009] In addition, in this specification and the claims, when expressing the mode of arranging one structure on another structure, if simply denoted as "on", unless otherwise specified, it shall include both the case where another structure is arranged directly on a certain structure in contact therewith and the case where another structure is arranged above a certain structure with yet another structure interposed therebetween.

[0010] (Embodiment 1) FIG. 1 is a schematic diagram of a stretchable device according to Embodiment 1. As shown in FIG. 1, the stretchable device 100 has a flat plate shape. The stretchable device 100 has a front surface 1 and a back surface 2 (the back surface 2 is not shown in FIG. 1; see FIG. 2) facing in opposite directions.

[0011] Hereinafter, the direction parallel to each of the front surface 1 and the back surface 2 is referred to as the planar direction. Also, one direction parallel to the planar direction is referred to as the first direction X. A direction parallel to the planar direction and intersecting the first direction X is referred to as the second direction Y.

[0012] The stretchable device 100 is formed in a rectangular (quadrilateral) shape in plan view. The front surface 1 has a pair of short sides 3 and a pair of long sides 4. The long sides 4 are parallel to the first direction X. The short sides 3 are parallel to the second direction Y. Thus, in this embodiment, the first direction X and the second direction Y are orthogonal to each other.

[0013] The stretchable device 100 is divided in plan view into a detection region 5 capable of detecting a load input to the stretchable device 100 and a frame-shaped peripheral region 6 surrounding the outside of the detection region 5. In FIG. 1, a boundary line L1 is drawn to facilitate understanding of the boundary between the detection region 5 and the peripheral region 6.

[0014] FIG. 2 is a diagram schematically showing a cross-section of the stretchable device according to Embodiment 1, and more specifically, is a cross-sectional view taken along line II-II of FIG. 3. As shown in FIG. 2, the stretchable device 100 has a first stretchable resin 60, a resin substrate 10, an array layer 30, and a second stretchable resin 70 laminated in order in a first lamination direction Z1. Further, a stretchable substrate 8 is constituted by the resin substrate 10 and the array layer 30.

[0015] Hereinafter, the direction in which the first stretchable resin 60, the resin substrate 10, the array layer 30, and the second stretchable resin 70 are laminated is referred to as the lamination direction. Also, with respect to the lamination direction, the direction in which the second stretchable resin 70 is arranged when viewed from the first stretchable resin 60 is referred to as a first lamination direction Z1, and the direction opposite to the first lamination direction Z1 is referred to as a second lamination direction Z2. Viewing the stretchable device 100 from a position in the first lamination direction Z1 is referred to as a plan view.

[0016] The first stretchable resin 60 and the second stretchable resin 70 have insulating properties, stretchability, and flexibility. Examples of the resin used as the first stretchable resin 60 and the second stretchable resin 70 include acrylic elastomers. Note that the first stretchable resin 60 and the second stretchable resin 70 of the present disclosure are not limited to acrylic elastomers, and may be acrylic resins, epoxy resins, urethane resins, etc., and are not particularly limited.

[0017] The first stretchable resin 60 and the second stretchable resin 70 are formed in a plate shape and extend in a plane direction. The surface of the first stretchable resin 60 in the second lamination direction Z2 constitutes the back surface 2 of the stretchable device 100. The first stretchable resin 60 has a first surface 61 facing the first lamination direction Z1. The resin substrate 10 is laminated on the first surface 61.

[0018] The surface of the second stretchable resin 70 in the first lamination direction Z1 constitutes the front surface 1 of the stretchable device 100. The surface 71 of the second stretchable resin 70 in the second lamination direction Z2 is adhered to the array layer 30. Frame portions 72 protruding in the second lamination direction Z2 from the surface 71 are provided at the ends of the second stretchable resin 70 in the first direction X and the ends in the second direction Y.

[0019] The frame portion 72 is formed in an annular shape in plan view and surrounds the outer peripheral sides of the resin base material 10 and the array layer 30. The surface 72a of the frame portion 72 in the second lamination direction Z2 is adhered to the first surface 61 of the first stretchable resin 60. Therefore, the first stretchable resin 60 and the second stretchable resin 70 cooperate with each other to form a housing that houses the resin base material 10 and the array layer 30.

[0020] The resin base material 10 is adhered to the first surface 61 of the first stretchable resin 60. The resin base material 10 has stretchability, flexibility, and insulation properties. The resin base material 10 is manufactured from a resin material such as, for example, non-photosensitive polyimide. Therefore, the elongation of the resin base material 10 in the embodiment is 30%.

[0021] FIG. 3 is an enlarged view of a part of the resin base material of Embodiment 1 as viewed from a position in the first lamination direction Z1. As shown in FIG. 3, the resin base material 10 includes a plurality of body portions 11 and a plurality of hinges 12 that extend in a planar direction while meandering. Although not particularly shown, the resin base material 10 is disposed in each of the detection region 5 and the peripheral region 6.

[0022] The body portion 11 is octagonal in plan view. The plurality of body portions 11 are arranged in the first direction X and the second direction Y and are spaced apart from each other. Note that the present disclosure is not limited to the octagonal shape of the body portion 11 in plan view, and may be a circular shape or other polygonal shapes.

[0023] The hinge 12 connects adjacent body portions 11. There are two types of hinges 12: a vertical hinge 12A that extends in the first direction X and a horizontal hinge 12B that extends in the second direction Y. In addition, a portion of the resin base material 10 where the body portion 11 and the hinge 12 are not provided is a through hole 19 that penetrates the resin base material 10 in the lamination direction. That is, the resin base material 10 has a plurality of through holes 19.

[0024] As shown in FIG. 2, the array layer 30 is not laminated in the region overlapping the relief hole 19. The relief hole 19 is filled with the second stretchable resin 70. Thereby, the stretchable device 100 has low rigidity in the portion adjacent to the relief hole 19 in the first direction X or the second direction Y, and has stretchability and flexibility (stretchable property). In other words, when a load acts on the stretchable device 100, the hinge 12 deforms. On the other hand, the deformation of the body portion 11 is small, and damage to the functional element (thin film transistor 40) laminated on the body portion 11 is suppressed.

[0025] Note that the relief hole 19 of the present embodiment is filled with the second stretchable resin 70, but the present disclosure may be filled with the first stretchable resin 60. Alternatively, the relief hole 19 may be filled with both the first stretchable resin 60 and the second stretchable resin 70. Or, the relief hole 19 may be filled with a resin material other than the first stretchable resin 60 and the second stretchable resin 70. In addition, nothing may be arranged in the relief hole 19, and it may be a space.

[0026] Next, details of the hinge 12 will be described. When the vertical hinge 12A is rotated 90°, it has the same shape as the horizontal hinge 12B. Therefore, hereinafter, the vertical hinge 12A will be described as a representative example.

[0027] FIG. 4 is an enlarged view of the vertical hinge of Embodiment 1. FIG. 5 is an enlarged view of the vertical hinge of Embodiment 1 when a tensile load acts in the first direction. For convenience of explanation, of the two body portions 11 sandwiching the vertical hinge 12A, one is referred to as the first body portion 11a and the other is referred to as the second body portion 11b.

[0028] As shown in FIG. 4, the vertical hinge 12A has four arc portions 20 formed in an arc shape in plan view. Thereby, the vertical hinge 12A extends in the first direction X while meandering in the second direction Y. In the present disclosure, the number of the arc portions 20 is not limited to four.

[0029] The four arc portions 20 are a first arc portion 21, a second arc portion 22, a third arc portion 23, and a fourth arc portion 24 arranged in order from the first body portion 11a toward the second body portion 11b. The first arc portion 21 and the fourth arc portion 24 form a quarter circle shape. The second arc portion 22 and the third arc portion 23 form a substantially semi-circular arc shape.

[0030] Further, the vertical hinge 12A has a linear first base portion 25 connecting the first body portion 11a and the first arc portion 21, and a linear second base portion 26 connecting the fourth arc portion 24 and the second body portion 11b.

[0031] The width W1 of the vertical hinge 12A is constant from one end to the other end of the vertical hinge 12A. That is, the width of each arc portion 20 is also W1.

[0032] As shown in FIG. 5, when a tensile load (see arrow F in FIG. 5) in the first direction X acts on the stretchable device 100, the first arc portion 21, the second arc portion 22, the third arc portion 23, and the fourth arc portion 24 each have an increased radius of curvature. As a result, the distance from one end to the other end of the vertical hinge 12A increases, and the body portions 11 are separated from each other.

[0033] Further, when the radius of curvature of each arc portion 20 increases, a tensile load (see arrows N1 to N4 in FIG. 5) acts on the inner peripheral side of each arc portion 20. On the other hand, a compressive load (see arrows G1 to G4 in FIG. 5) acts on the outer peripheral side of each arc portion 20. That is, in the first arc portion 21, the closer to the inner peripheral edge 21a, the greater the tensile strain generated. Also, the closer to the outer peripheral edge 21b, the greater the compressive strain generated. Similarly, in the second arc portion 22, the closer to the inner peripheral edge 22a, the greater the tensile strain generated, and the closer to the outer peripheral edge 22b, the greater the compressive strain generated. In the third arc portion 23, the closer to the inner peripheral edge 23a, the greater the tensile strain generated, and the closer to the outer peripheral edge 23b, the greater the compressive strain generated. In the fourth arc portion 24, the closer to the inner peripheral edge 24a, the greater the tensile strain generated, and the closer to the outer peripheral edge 24b, the greater the compressive strain generated.

[0034] Next, the array layer 30 will be described. The array layer 30 has a plurality of insulating layers (not shown) laminated in the lamination direction, and a load detection circuit embedded in the plurality of insulating layers and insulated from the outside. Hereinafter, the load detection circuit and the insulating layer will be described in this order.

[0035] The load detection circuit provided in the array layer 30 is a circuit for detecting a planar load input to the stretchable device 100. Note that in the present disclosure, the electric circuit provided in the array layer 30 may be, for example, a circuit for detecting pressure input to the surface 1, and is not particularly limited.

[0036] FIG. 6 is a schematic diagram schematically showing each configuration of the load detection circuit disposed in the body portion of Embodiment 1. As shown in FIG. 6, the load detection circuit includes a strain gauge 31 (see FIG. 4), a thin film transistor 40, a gate line 41, a first signal line 42, a second signal line 43, a first wiring 44, a second wiring 45, a second resistance portion 52, a third resistance portion 53, a fourth resistance portion 54, a first potential detection line 55, and a second potential detection line 56.

[0037] The strain gauge 31 is a detection element that expands and contracts in accordance with the strain generated in the hinge 12 and whose resistance value increases or decreases. As shown in FIG. 4, the strain gauge 31 is disposed only on each vertical hinge 12A. Note that although the strain gauge 31 of the present embodiment is disposed only on the vertical hinge 12A, in the present disclosure, the strain gauge 31 may be disposed only on the horizontal hinge 12B, or may be disposed on both the vertical hinge 12A and the horizontal hinge 12B.

[0038] The strain gauge 31 has a first strain gauge 32, a second strain gauge 33, and a folded portion 34. The first strain gauge 32 and the second strain gauge 33 extend along the vertical hinge 12A and are disposed parallel to each other. The folded portion 34 is disposed in the second body portion 11b and connects the ends of the first strain gauge 32 and the second strain gauge 33 to each other.

[0039] The strain gauge 31 extends from the first body part 11a to the second body part 11b, and then bends back from the second body part 11b and returns to the first body part 11a. That is, the strain gauge 31 of the present embodiment has two strain gauges (the first strain gauge 32 and the second strain gauge 33). Therefore, it can detect a larger amount of strain than in the case of a single strain gauge, and the detection sensitivity is high. Note that the present disclosure may be configured by a single strain gauge.

[0040] In addition, as shown in FIG. 6, one end of the first strain gauge 32 (the starting end 31a of the strain gauge 31) is disposed on the first body part 11a. One end of the second strain gauge 33 (the terminal end 31b of the strain gauge 31) is disposed on the first body part 11a.

[0041] As shown in FIG. 6, a thin film transistor 40 is disposed one by one for each body part 11. The starting end 31a of the strain gauge 31 is connected to a source electrode (not shown) of the thin film transistor 40. Hereinafter, the connection point between the thin film transistor 40 and the starting end 31a of the strain gauge 31 is referred to as a first connection point P1.

[0042] The gate line 41 is disposed across a plurality of horizontal hinges 12B and a plurality of body parts 11 and extends in the second direction Y. The gate line 41 is connected to a gate electrode (not shown) of the thin film transistor 40. In addition, a plurality of thin film transistors 40 arranged in the second direction Y are connected to one gate line 41.

[0043] The first signal line 42 is disposed across a plurality of vertical hinges 12A and a plurality of body parts 11 and extends in the first direction X. Similarly, the second signal line 43 is disposed across a plurality of vertical hinges 12A and a plurality of body parts 11 and extends in the first direction.

[0044] The first signal line 42 is connected to a drain electrode (not shown) of the thin film transistor 40 in each body part 11. Therefore, a plurality of thin film transistors arranged in the first direction X are connected to one first signal line 42.

[0045] The first wiring 44 is a wiring arranged in the body portion 11. One end of the first wiring 44 is connected to the end 31b of the strain gauge 31. Hereinafter, the connection point between the first wiring 44 and the end 31b of the strain gauge 31 is referred to as the first intermediate point P2. The other end of the first wiring 44 is connected to the second signal line 43. Hereinafter, the connection point between the first wiring 44 and the second signal line 43 is referred to as the second connection point P3. A plurality of thin film transistors 40 arranged in the first direction X are connected to one second signal line 43. Further, a second resistance portion 52 is provided on the first wiring 44.

[0046] The second wiring 45 is a wiring arranged in the body portion 11. The second wiring 45 connects the first connection point P1 and the second connection point P3. Therefore, the second wiring 45 forms a parallel circuit with respect to the circuit composed of the strain gauge 31 and the first wiring 50, with the start end 31a of the strain gauge 31 as the branch point. Further, a third resistance portion 53 and a fourth resistance portion 54 are arranged on the second wiring 45. Hereinafter, a certain point between the third resistance portion 53 and the fourth resistance portion 54 in the second wiring 45 is referred to as the second intermediate point P4.

[0047] The first potential detection line 55 extends from the first intermediate point P2 and is a wiring for detecting the potential of the end 31b of the strain gauge 31. The second potential detection line 56 extends from the second intermediate point P4 of the second wiring 45 and is an electrical wiring for detecting the potential of the second intermediate point P4 of the second wiring 51. The first potential detection line 55 is arranged across a plurality of horizontal hinges 12B and a plurality of body portions, and extends in one direction of the second direction Y. Further, the second potential detection line 56 is arranged across a plurality of horizontal hinges 12B and a plurality of body portions 11, and extends in the other direction of the second direction Y.

[0048] As described above, according to the present embodiment, the circuit including the strain gauge 31 constitutes a Wheatstone bridge circuit. Hereinafter, the details of the Wheatstone bridge circuit of the present embodiment will be described.

[0049] FIG. 7 is a diagram schematically showing the Wheatstone bridge circuit of Embodiment 1. The second resistance value R2 of the second resistor part 52, the third resistance value R3 of the third resistor part 53, and the fourth resistance value R4 of the fourth resistor part 54 are each the same as the first resistance value R1 of the strain gauge 31 when the hinge 12 is not in a modified form (R1 = R2 = R3 = R4). Further, the second resistor part 52, the third resistor part 53, and the fourth resistor part 54 are provided in the body part 11. Therefore, even when the hinge 12 is deformed, the change amount of the resistance value is zero.

[0050] As shown in FIG. 7, when detecting the strain amount by the strain gauge 31, a detection signal which is a predetermined first potential V1 is supplied to the first signal line 42. Further, a second potential V2 lower than the first potential V1 is supplied to the second signal line 43 (V2 > V1). In the present embodiment, the second potential V2 is 0V. Therefore, when the thin film transistor 40 is closed, the potential of the first connection point P1 (the start end 31a of the strain gauge 31) becomes the first potential V1.

[0051] When the hinge 12 is not deformed, the first resistance value R1 of the strain gauge 31 does not change. Therefore, the first resistance value R1 of the strain gauge 31, the second resistance value R2 of the second resistor part 52, the third resistance value R3 of the third resistor part 53, and the fourth resistance value R4 of the fourth resistor part 54 are equal to each other. Therefore, the potential V3 of the first intermediate point P2 read by the first potential detection line 55 and the potential V4 of the second intermediate point P4 read by the second potential detection line 56 are equal.

[0052] On the other hand, when the hinge 12 is deformed and strain is generated in the strain gauge 31, the first resistance value R1 changes and the potential V3 of the first intermediate point P2 changes. Therefore, a potential difference is generated between the first intermediate point P2 and the second intermediate point P4. From the above, by detecting the potential V3 and the potential V4, the change amount of the resistance value of the strain gauge 31 can be detected.

[0053] Also, as shown in FIG. 1, the array layer 30 includes a connection portion 101 disposed in the peripheral region 6, a gate line driving circuit 102, a first signal line selection circuit 103, a second signal line selection circuit 104, a first potential detection line selection circuit 105, and a second potential detection line selection circuit 106 for driving the load detection circuit.

[0054] The connection portion 101 is for connecting to a driving IC (Integrated Circuit) disposed outside the stretchable device 100. Note that the driving IC may be mounted as a COF (Chip On Film) on a flexible printed circuit board or a rigid substrate (not shown) connected to the connection portion 101. Alternatively, the driving IC may be mounted as a COG (Chip On Glass) in the peripheral region 6 of the first stretchable resin 60.

[0055] The gate line driving circuit 102 is a circuit that drives a plurality of gate lines 41 (see FIG. 7) based on various control signals from the driving IC. The gate line driving circuit 102 sequentially or simultaneously selects a plurality of gate lines 41 and supplies a gate driving signal to the selected gate lines 41.

[0056] The first signal line selection circuit 103 is a switch circuit that sequentially or simultaneously selects a plurality of first signal lines 42. The first signal line selection circuit 103 connects the first signal line 42 to the driving IC based on a selection signal supplied from the driving IC. Thereby, a predetermined first potential V1 is applied to the first signal line 42.

[0057] The second signal line selection circuit 104 is a switch circuit that sequentially or simultaneously selects a plurality of second signal lines 43. The second signal line selection circuit 104 connects the second signal line 43 to the driving IC based on a selection signal supplied from the driving IC. Thereby, a predetermined second potential V2 is applied to the second signal line 43. In this embodiment, the second potential V2 is 0V.

[0058] The first potential detection line selection circuit 105 is a switch circuit that sequentially or simultaneously selects a plurality of first potential detection lines 55. The first potential detection line selection circuit 105 connects the selected first potential detection line 55 to the driving IC based on a selection signal supplied from the driving IC. Thereby, the potential V3 of the first intermediate point P2 is sent to the driving IC.

[0059] The second potential detection line selection circuit 106 is a switch circuit that sequentially or simultaneously selects a plurality of second potential detection lines 56. The second potential detection line selection circuit 106 connects the selected second potential detection line 56 to the driving IC based on a selection signal supplied from the driving IC. Thereby, the potential V4 of the second intermediate point P4 is sent to the driving IC.

[0060] Next, the insulating layer constituting the array layer 30 will be described. Examples of the material of the insulating layer include a photosensitive organic material or an inorganic material. More specifically, examples of the photosensitive organic material include polyimide, acrylic, polybenzoxazole (PBO), and phenol. Examples of the inorganic material film include SiO and SiN. The elongation of the insulating layer formed of these materials is about 10%, which is smaller than the elongation of the resin base material 10.

[0061] FIG. 8 is an enlarged view of the array layer according to Embodiment 1 from the first stacking direction. In FIG. 8, in order to easily distinguish the resin base material 10 and the array layer 30, dots are added to the range of the array layer 30. As shown in FIG. 8, the array layer 30 includes a plurality of array layers 131 for body parts laminated on the body part 11 and a plurality of array layers 132 for hinges laminated on the hinge.

[0062] The array layer 131 for body parts is formed in an octagonal shape in plan view and has the same shape as the body part 11. The array layer 132 for hinges extends along the hinge 12, and both ends are connected to the array layer 131 for body parts.

[0063] The array layer 132 for the hinge has an array layer 140 for the arc portion laminated on the arc portion 20. The array layer 140 for the arc portion has a first array layer 141 for the first arc portion laminated on the first arc portion 21, a second array layer 142 for the second arc portion laminated on the second arc portion 22, a third array layer 143 for the third arc portion laminated on the third arc portion 23, and a fourth array layer 144 for the fourth arc portion laminated on the fourth arc portion 24. Further, the array layer 132 for the hinge has a first array layer 145 for the first base portion laminated on the first base portion 25 and a second array layer 146 for the second base portion laminated on the second base portion 26.

[0064] The width W2 of the array layer 132 for the hinge is constant from one end to the other end of the array layer 132 for the hinge. That is, the first array layer 141 for the first arc portion, the second array layer 142 for the second arc portion, the third array layer 143 for the third arc portion, the fourth array layer 144 for the fourth arc portion, the first array layer 145 for the first base portion, and the second array layer 146 for the second base portion each have a width of W2.

[0065] The width W2 of the array layer 132 for the hinge is smaller than the width W1 of the hinge 12 (see FIG. 4). For this reason, a part of the surface 12a in the first lamination direction Z1 of the hinge 12 is not covered by the array layer 132 for the hinge.

[0066] FIG. 9 is a cross-sectional view taken along the arrow IX-IX line in FIG. 8. As shown in FIG. 9, the center O132 in the width direction of the array layer 132 for the hinge and the center O12 in the width direction of the hinge 12 overlap in the lamination direction. That is, the array layer 132 for the hinge is disposed at the center in the width direction of the hinge 12. Therefore, the inner peripheral edge 140a of the array layer 140 for the arc portion (the inner peripheral circle 142a of the second array layer 142 for the second arc portion in FIG. 9) is disposed at a distance from the inner peripheral edge 22a of the second arc portion 22 toward the outer peripheral edge 22b of the second arc portion 22.

[0067] From the above, the array layer 132 for the hinge in the present embodiment does not overlap with the inner peripheral side of the arc portion 20 (see the range indicated by the arrows N1 to N4 in FIG. 5). That is, even when a tensile load acts on the hinge 12, a large tensile load does not act on the array layer 140 for the arc portion.

[0068] Next, the effects of Embodiment 1 will be described. Generally, the elongation of the resin substrate 10 is about 30% or more, and the elongation of the insulating layer constituting the array layer 30 is about 10%. Such a difference in elongation can be grasped by performing a bending test. When a bending test is performed, cracks occur in the insulating layer, but no cracks occur in the resin substrate. Hereinafter, the commonly performed bending test will be described. Note that the bending test includes three steps: a first step S1, a second step S2, and a third step S3.

[0069] FIG. 10 is a cross-sectional view for explaining the first step of the bending test. In the first step S1 of the bending test, a sample 200 having a resin substrate 210 and an insulating layer 230 laminated on the resin substrate 210 is prepared. Note that the thickness H1 of the resin substrate 210 is 5 μm, and the thickness H2 of the insulating layer 230 is 1.5 μm.

[0070] Next, the sample 200 is bent and folded in half. Note that the sample 200 is bent so that the back surfaces 202 of the sample 200 face each other. Further, a spacer 300 is inserted between the back surfaces 202 of the sample 200. The sample 200 is sandwiched between two flat plates 400 so that the sample 200 abuts on the spacer 300.

[0071] In this way, a folded portion 220 having an arc-shaped cross-sectional shape is formed in a part of the sample 200. In the first step S1, the radius of curvature r1 of the surface 221 of the folded portion 220 is set to 0.2 mm. In this first step S1, no cracks occur in the resin substrate 210 and the insulating layer 230. Note that in FIG. 11 and the like, the virtual circle with the radius of curvature r1 hardly overlaps with the surface 221. For this reason, the virtual circle with the radius of curvature r1 shows a circle having a slightly larger diameter than the surface 221.

[0072] FIG. 11 is a cross-sectional view for explaining the second step of the bending test. In the second step S2 of the bending test, a spacer 301 thinner than the spacer 300 used in the first step S1 is used. Also, the radius of curvature r1 of the surface 221 of the folded-back portion 220 is made less than 0.2 mm. According to this, cracks 500 occur in the portion of the insulating layer 230 that constitutes the folded-back portion 220.

[0073] FIG. 12 is a cross-sectional view for explaining the third step of the bending test. In the third step S3 of the bending test, the spacer 301 used in the second step S2 is removed, and the back surfaces 202 of the sample 200 are brought into contact with each other. Also in the third step S3, no cracks occur in the resin base material 210.

[0074] From the above, when a large tensile load acts on the stretchable device 100, strain may occur in the resin base material 10 and cracks may occur in the hinge array layer 132. However, as shown in FIGS. 8 and 9, the hinge array layer 132 of the present embodiment is not disposed at a position (near the inner peripheral edge 20a of the arc portion 20) where a large tensile load acts. That is, the arc portion array layer 140 is disposed so that a large tensile load does not act thereon. For this reason, cracks are less likely to occur on the inner peripheral side of the arc portion array layer 140.

[0075] Although Embodiment 1 has been described above, the present disclosure is not limited to the examples described in Embodiment 1. The hinge array layer 132 of Embodiment 1 has a constant size in the width direction from one end to the other end and is the same as the width W2 of the arc portion array layer 140, but the present disclosure is not limited to this. FIG. 13 is an enlarged view of the array layer of Modification 1 viewed from the first stacking direction. For example, as shown in FIG. 13, the widths of the first base array layer 145 and the second base array layer 146 in the width direction may be the same as the width W1 of the hinge 12. Even in such a modification, the arc portion array layer 140 is separated from the inner peripheral edge 20a of the arc portion 20. For this reason, cracks are less likely to occur in the arc portion array layer 140.

[0076] In Embodiment 1, the hinge array layer 132 (arc portion array layer 140) is disposed at the center in the width direction of the hinge 12 (arc portion 20). However, in the present disclosure, the arc portion array layer 140 only needs to be separated from the inner peripheral edge 20a of the arc portion 20, and is not limited to the example shown in Embodiment 1. FIG. 14 is an enlarged view of the array layer of Modification 2 viewed from the first stacking direction. For example, as shown in FIG. 14, the arc portion array layer 140 may be disposed closer to the outer peripheral edge 20b than the inner peripheral edge 20a of the arc portion 20. According to this, when a tensile load acts on the hinge 12, a compressive load acts on the arc portion array layer 140. In addition, the insulating layer constituting the array layer 30 has a small elongation but a high durability against compressive loads. Therefore, cracks are less likely to occur in the arc portion array layer 140.

Explanation of Signs

[0077] 5 Detection region 6 Peripheral region 8 Stretchable base material 10 Resin base material 11 Body portion 12 Hinge 12A Vertical hinge 12B Horizontal hinge 19 Cutout hole 20 Arc portion 20a Inner peripheral edge 21 First arc portion 22 Second arc portion 23 Third arc portion 24 Fourth arc portion 30 Array layer 31 Strain gauge 40 Thin film transistor 41 Gate line 42 First signal line 43 Second signal line 44 First wiring 45 Second wiring 55 First potential detection line 56 Second potential detection line 60 First stretchable resin 70 Second stretchable resin 100 Stretchable device 131 Array layer for the body part 132 Array layer for the hinge 140 Array layer for the arc part 140a Inner peripheral edge 141 Array layer for the first arc part 142 Array layer for the second arc part 143 Array layer for the third arc part 144 Array layer for the fourth arc part 210 Resin substrate 230 Insulating layer 200 Specimen 300 Spacer 400 Flat plate 500 Crack

Claims

1. A stretchable substrate having a resin substrate and an array layer laminated in sequence, The resin substrate, A plurality of body portions arranged at intervals from each other in a plane direction intersecting the lamination direction in which the resin substrate and the array layer are laminated, A plurality of hinges extending while meandering in the plane direction and connecting the body portions to each other, having, The hinge has an arc-shaped arc portion when viewed from the lamination direction, Among the array layers, a portion laminated on the hinge is a hinge array layer, Among the hinge array layers, a portion laminated on the arc portion is an arc-shaped array layer for arc portion, The width size from the inner peripheral edge to the outer peripheral edge of the arc-shaped array layer for arc portion is smaller than the width from the inner peripheral edge to the outer peripheral edge of the arc portion, The inner peripheral edge of the arc-shaped array layer for arc portion is arranged at a distance from the inner peripheral edge of the arc portion toward the outer peripheral edge of the arc portion Stretchable device.

2. The arc-shaped array layer for arc portion is arranged at the central portion in the width direction of the arc portion The stretchable device according to claim 1.

3. The arc-shaped array layer for arc portion is arranged closer to the outer peripheral edge than the inner peripheral edge of the arc portion The stretchable device according to claim 1.

4. The width size in the width direction from one end to the other end of the hinge array layer is constant and is the same as the width of the arc-shaped array layer for arc portion The stretchable device according to any one of claims 1 to 3.

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