Stretchable device

Abstract

To provide a stretchable device having a highly sensitive semiconductor strain gauge.SOLUTION: A stretchable device includes a first elastic resin, a resin base material, an array layer and a second elastic resin sequentially laminated. The resin base material includes a plurality of body parts, and a plurality of hinge parts connecting the body parts to each other. The array layer includes a plurality of thin-film transistors arranged at the body parts, and a plurality of strain gauges arranged at the hinge parts. The strain gauge includes a semiconductor strain gauge formed with a semiconductor material in part of the lengthwise direction. An impurity density of the semiconductor strain gauge is higher than an impurity density of the thin-film transistor.SELECTED DRAWING: Figure 6

Description

[Technical field]

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

[0002] The stretchable device has excellent elasticity and flexibility. Such a stretchable device includes an array layer, a resin substrate on which the array layer is provided, and a pair of elastic resins sandwiching the array layer and the resin substrate. The resin substrate has body portions arranged in a matrix and hinge portions connecting the body portions to each other. The hinge portion of Patent Document 1 has a plurality of arc portions and has a meandering shape. When a tensile load acts on the stretchable device, the arc portions of the hinge portion are deformed so as to expand. As a result, the body portions are separated from each other, and the stretchable device is elongated.

[0003] Furthermore, thin film transistors (hereinafter sometimes abbreviated as "TFTs") may be provided in the array layer of the stretchable device. As shown in Patent Document 2 below, impurities are injected into the semiconductor layer of the TFT during the manufacturing process of the TFT. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-118273 [Patent Document 2] JP 2023-28988 A Summary of the Invention [Problem to be solved by the invention]

[0005] In recent years, in order to detect the load acting on a stretchable device, the installation of a strain gauge in the hinge section and the detection of the amount of strain (deformation) in the hinge section have been considered. In addition, the use of semiconductor strain gauges manufactured from semiconductor materials, which have a higher gauge factor than metal materials, as strain gauges has been considered. Here, if the semiconductor strain gauges are manufactured in the same process as TFTs, the semiconductor strain gauges will have the same impurity concentration as TFTs. Although semiconductor strain gauges with the same impurity concentration as TFTs have a higher gauge factor than metal strain gauges, there is a demand for semiconductor strain gauges with higher sensitivity.

[0006] An object of the present invention is to provide a stretchable device having a highly sensitive semiconductor strain gauge. [Means for solving the problem]

[0007] A stretchable device according to one embodiment of the present disclosure includes a first elastic resin, a resin substrate, an array layer, and a second elastic resin, which are laminated in this order. The resin substrate includes a plurality of body portions and a plurality of hinge portions connecting the body portions to each other. The array layer includes a plurality of thin film transistors disposed in the body portions and a plurality of strain gauges disposed in the hinge portions. The strain gauge includes a semiconductor strain gauge formed of a semiconductor material in a portion of its length. The impurity concentration of the semiconductor strain gauge is higher than the impurity concentration of the thin film transistor. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic perspective view of a stretchable device according to an embodiment. [Diagram 2] FIG. 2 is a schematic diagram showing a cross section of a stretchable device according to an embodiment, and more specifically, a cross section taken along line II-II in FIG. [Diagram 3] FIG. 3 is an enlarged view of a part of a resin substrate viewed from the front surface of a stretchable device according to an embodiment. [Figure 4]FIG. 4 is an enlarged view of the first hinge of the embodiment. [Diagram 5] FIG. 5 is an enlarged view of the vertical hinge portion of the embodiment when a load that stretches the vertical hinge portion in the first direction is applied thereto. [Figure 6] FIG. 6 is a plan view illustrating the components of the load detection circuit disposed in the hinge portion according to the embodiment. [Figure 7] FIG. 7 is a plan view illustrating the components of the load detection circuit disposed in the body portion according to the embodiment. [Figure 8] FIG. 8 is a diagram illustrating a Wheatstone bridge circuit according to the embodiment. [Figure 9] FIG. 9 is a diagram (graph) showing experimental data of the example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The form (embodiment) 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 embodiment. In addition, the components described below include those that a person skilled in the art can easily imagine and those that are substantially the same. Furthermore, the components described below can be appropriately combined. Note that the disclosure is merely an example, and those that a person skilled in the art can easily imagine appropriate modifications while maintaining the gist of the invention are naturally included in the scope of the present invention. In order to make the explanation clearer, the drawings may be schematic in terms of the width, thickness, shape, etc. of each part compared to the actual embodiment, but are merely an example and do not limit the interpretation of the present invention. In addition, in this specification and each figure, the same reference numerals are given to components similar to those described above with respect to the previous figures, and detailed explanations may be omitted as appropriate.

[0010] Furthermore, in this specification and the claims, when expressing an aspect of arranging another structure on top of a certain structure, the term "on top" is used, unless otherwise specified, to include both the case where another structure is arranged directly on top of a certain structure so as to be in contact with the certain structure, and the case where another structure is arranged above a certain structure via yet another structure.

[0011] (Embodiment) Fig. 1 is a schematic perspective view of a stretchable device according to an embodiment. 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 (not shown in Fig. 1; see Fig. 2) that face in opposite directions.

[0012] Hereinafter, a direction parallel to each of the front surface 1 and the back surface 2 will be referred to as a planar direction. A direction parallel to the planar direction will be referred to as a first direction X. A direction parallel to the planar direction and intersecting with the first direction X will be referred to as a second direction Y.

[0013] The stretchable device 100 is formed into a rectangle (quadrilateral) in a plan view. Thus, the surface 1 has a pair of short sides 3 and a pair of long sides 4. The long sides 1d are parallel to the first direction X. The short sides 1c are parallel to the second direction Y. Thus, in this embodiment, the first direction X and the second direction Y are perpendicular to each other.

[0014] In a plan view, the stretchable device 100 is divided into a detection area 5 in which a load input to the stretchable device 100 can be detected, and a frame-shaped peripheral area 6 that surrounds the outside of the detection area 5. In FIG. 1, a boundary line L1 is drawn to make the boundary between the detection area 5 and the peripheral area 6 easier to understand.

[0015] Fig. 2 is a schematic diagram showing a cross section of a stretchable device according to an embodiment, specifically, a cross section taken along line II-II in 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, which are laminated in this order.

[0016] Hereinafter, the direction in which the first elastic resin 60, the resin substrate 10, the array layer 30, and the second elastic resin 70 are laminated is referred to as the thickness direction. With respect to the thickness direction, the direction in which the second elastic resin 70 is arranged as viewed from the first elastic resin 60 is referred to as the first thickness direction Z1, and the opposite direction to the first thickness direction Z1 is referred to as the second thickness direction Z2. Furthermore, viewing the stretchable device 100 from the first thickness direction Z1 is referred to as a planar view.

[0017] The first elastic resin 60 and the second elastic resin 70 have insulating properties, elasticity, and flexibility. An example of a resin used as the first elastic resin 60 and the second elastic resin 70 is an acrylic elastomer. The first elastic resin 60 and the second elastic resin 70 of the present disclosure are not limited to acrylic elastomers, and may be acrylic resins, epoxy resins, urethane resins, or the like, and are not particularly limited.

[0018] The first elastic resin 60 and the second elastic resin 70 are formed in a plate shape and extend in a planar direction. The surface of the first elastic resin 60 in the second thickness direction Z2 constitutes the back surface 2 of the stretchable device 100. The first elastic resin 60 has a first surface 61 facing the first thickness direction Z1. The resin base material 10 is laminated on the first surface 61.

[0019] A surface of the second elastic resin 70 in the first thickness direction Z1 constitutes a surface 1 of the stretchable device 100. A surface 71 of the second elastic resin 70 in the second thickness direction Z2 is adhered to the array layer 30. An end of the second elastic resin 70 in the first direction X and an end of the second direction Y are provided with frame portions 72 that protrude in the second thickness direction Z2 beyond the surface 71.

[0020] The frame 72 is formed in a ring shape in a plan view, and surrounds the outer periphery of the resin substrate 10 and the array layer 30. A surface 72a of the frame 72 in the second thickness direction Z2 is bonded to the first surface 61 of the first elastic resin 60. Thus, the first elastic resin 60 and the second elastic resin 70 cooperate with each other to form a housing that accommodates the resin substrate 10 and the array layer 30.

[0021] The resin base material 10 is adhered to a first surface 61 of the first elastic resin 60. The resin base material 10 has elasticity, flexibility, and insulating properties. The resin base material 10 is made of a resin material such as polyimide.

[0022] 3 is an enlarged view of a part of a resin substrate viewed from the front side of a stretchable device according to an embodiment. As shown in FIG. 3, the resin substrate 10 includes a plurality of body portions 11 and a plurality of hinge portions 12 that extend in a planar direction while meandering. When viewed in a plan view, the body portions 11 and the hinge portions 12 are each disposed in a detection region 5.

[0023] The body portion 11 has a quadrangular (square) shape in plan view. The body portion 11 is arranged so that four corners point in the first direction X and the second direction Y. The multiple 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 shape of the body portion 11 in plan view in the present disclosure is not limited to a quadrangular shape, and may be a circular shape or another polygonal shape.

[0024] The hinge portion 12 connects adjacent body portions 11. There are two types of hinge portions 12: vertical hinge portions 12A extending in the first direction X, and horizontal hinge portions 12B extending in the second direction Y. Furthermore, portions of the resin base material 10 where the body portions 11 and hinge portions 12 are not provided are formed as lightening holes 19 penetrating the resin base material 10 in the thickness direction. In other words, the resin base material 10 has a plurality of lightening holes 19.

[0025] 2, the array layer 30 is not laminated in the area overlapping the lightening hole 19. The lightening hole 19 is filled with a second elastic resin 70. As a result, the stretchable device 100 has low rigidity in the area overlapping with the lightening hole 19 and is provided with elasticity and flexibility (stretchability). In other words, when a load is applied to the stretchable device 100, the hinge portion 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.

[0026] Although the lightening hole 19 in the present embodiment is filled with the second elastic resin 70, in the present disclosure, it may be filled with the first elastic resin 60. Alternatively, the lightening hole 19 may be filled with both the first elastic resin 60 and the second elastic resin 70. Alternatively, the lightening hole 19 may be filled with a resin material other than the first elastic resin 60 and the second elastic resin 70. In addition, nothing may be placed in the lightening hole 19, and it may be a space.

[0027] Next, a detailed description will be given of the hinge portion 12. When the vertical hinge portion 12A is rotated by 90 degrees, it has the same shape as the horizontal hinge portion 12B. Therefore, in the following, the vertical hinge portion 12A will be described as a representative example.

[0028] Fig. 4 is an enlarged view of the first hinge of the embodiment. Fig. 5 is an enlarged view of the vertical hinge of the embodiment when a load that stretches in the first direction is applied. Note that the imaginary line K shown in Figs. 4 and 5 is an imaginary line that passes through the center of the vertical hinge 12A in the width direction. For convenience of explanation, one of the two body parts 11 sandwiching the vertical hinge 12A is referred to as the first body part 11a and the other is referred to as the second body part 11b.

[0029] As shown in Fig. 4, the vertical hinge portion 12A has four bent portions 20 and extends in a meandering manner in the first direction X. Each bent portion 20 in this embodiment is formed in an arc shape. Note that the bent portions of the present disclosure may be formed in an angular shape instead of an arc shape. Also, the number of bent portions is not limited to four.

[0030] The four bent portions 20 are a first arc portion 21, a second arc portion 22, a third arc portion 23, and a fourth arc portion 24, which are arranged in this order from the first body portion 11a toward the second body portion 11b. The first arc portion 21 and the fourth arc portion 24 are quadrant-shaped and bent at 90 degrees. The second arc portion 22 and the third arc portion 23 are semicircular and bent at 180 degrees. A linear connection portion 25 is provided between the second arc portion 22 and the third arc portion 23.

[0031] Each bent portion 20 is divided into an inner periphery (first inner periphery 21N, second inner periphery 22N, third inner periphery 23N, fourth inner periphery 24N) located on the inside (inner periphery side) and an outer periphery (first outer periphery 21G, second outer periphery 22G, third outer periphery 23G, fourth outer periphery 24G) located on the outside (outer periphery side) with the imaginary line K as the boundary. In FIG. 4, the inner periphery and the outer periphery are surrounded by an ellipse to clarify the range of the inner periphery and the outer periphery of each bent portion 20. However, the entire area on the inner periphery side of the imaginary line K is the inner periphery, and the entire area on the outer periphery side of the imaginary line K is the outer periphery. Therefore, the area surrounded by the ellipse in FIG. 4 is a part of the inner periphery or the outer periphery.

[0032] As shown in Fig. 5, when a tensile load (see arrow F in Fig. 5) acts on the stretchable device 100 in the first direction X, the first arc portion 21, the second arc portion 22, the third arc portion 23, and the fourth arc portion 24 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 becomes larger, and the body portions 11 become separated from each other. Furthermore, when the bending angle of each bend portion 20 becomes larger, the following load (stress) acts on the inner and outer peripheries of each bend portion 20.

[0033] A tensile load acts on the first inner circumference 21N of the first arc portion 21. A compressive load acts on the first outer circumference 21G of the first arc portion 21. A tensile load acts on the second inner circumference 22N of the second arc portion 22. A compressive load acts on the second outer circumference 22G of the second arc portion 22. A tensile load acts on the third inner circumference 23N of the third arc portion 23. A compressive load acts on the third outer circumference 23G of the third arc portion 23. A tensile load acts on the fourth inner circumference 24N of the fourth arc portion 24. A compressive load acts on the fourth outer circumference 24G of the fourth arc portion 24. As a result, a tensile strain is generated in the inner circumference of each bent portion 20, while a compressive strain is generated in the outer circumference of each bent portion 20.

[0034] Although not shown, when a compressive load in the first direction X acts on the vertical hinge portion 12A, the first arc portion 21, the second arc portion 22, the third arc portion 23, and the fourth arc portion 24 are deformed so that their curvatures become larger. As a result, the distance from one end to the other end of the vertical hinge portion 12A becomes smaller, and the body portions 11 become closer to each other. Also, a compressive load acts on the inner periphery of each bent portion 20, while a tensile load acts on the outer periphery of each bent portion 20.

[0035] As described above, when a load acts on the vertical hinge portion 12A, large strain occurs at the inner and outer peripheries of each bending portion 20. Meanwhile, unlike each bending portion 20, the vertical hinge portion 12A may have a region (deformation reduction region L2) in which the amount of deformation is suppressed to 1% or less. In this embodiment, as shown in Figs. 4 and 5, the connection portion 25 between the second arc portion 22 and the third arc portion 23 corresponds to the deformation reduction region L2. In other words, even if a load acts on the vertical hinge portion 12A, the amount of deformation of the connection portion 25 is suppressed to 1% or less.

[0036] The array layer 30 has a plurality of insulating layers (not shown) stacked in the thickness direction, and a load detection circuit embedded in the insulating layers and insulated from the outside. The load detection circuit is a circuit for detecting a load input to the stretchable device 100.

[0037] Fig. 6 is a plan view showing each component of the load detection circuit arranged in the hinge part of the embodiment. Fig. 7 is a plan view showing each component of the load detection circuit arranged in the body part of the embodiment. As shown in Figs. 6 and 7, the load detection circuit includes a strain gauge 31 (see Fig. 6), a thin film transistor 40 (see Fig. 7), a gate line 41 (see Fig. 7), a first signal line 42, a second signal line 43, a first wiring 44 (see Fig. 7), a second wiring 45 (see Fig. 7), a second resistor 52 (see Fig. 7), a third resistor 53 (see Fig. 7), a fourth resistor 54 (see Fig. 7), a first potential detection line 55 (see Fig. 7), and a second potential detection line 56 (see Fig. 7).

[0038] 6, the strain gauges 31 are disposed only at the vertical hinge portions 12A. Note that, although the strain gauges 31 in this embodiment are disposed only at the vertical hinge portions 12A, the present disclosure may also dispose the strain gauges 31 only at the horizontal hinge portions 12B, or at both the vertical hinge portions 12A and the horizontal hinge portions 12B.

[0039] 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 portion 12A and are arranged parallel to each other. The first strain gauge 32 and the second strain gauge 33 are arranged so as to overlap with the inner peripheral portions (the first inner peripheral portion 21N, the second inner peripheral portion 22N, the third inner peripheral portion 23N, and the fourth inner peripheral portion 24N; see FIGS. 4 and 5) at each bending portion 20 of the hinge portion 12. Therefore, when the vertical hinge portion 12A is deformed, a common strain (tensile strain or compressive strain) is generated in the first strain gauge 32 and the second strain gauge 33 at the portions where they overlap with each bending portion 20.

[0040] 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. Thus, the strain gauge 31 of this embodiment extends from the first body portion 11a to the second body portion 11b, and then folds back from the second body to return to the first body portion 11a. As described above, the strain gauge 31 of this embodiment has two strain gauges (the first strain gauge 32 and the second strain gauge 33). Therefore, it is possible to detect a larger amount of strain than when it is composed of one strain gauge, and the detection sensitivity is high. Note that the present disclosure may be composed of one strain gauge.

[0041] The second strain gauge 33 is a metal strain gauge made entirely of metal material in the length direction. On the other hand, the first strain gauge 32 is partially made of semiconductor strain gauge 35, and the remaining part is a metal strain gauge. The semiconductor strain gauge 35 has a higher gauge factor than a metal strain gauge. Therefore, the strain gauge 31 has a higher sensitivity than a gauge gauge made entirely of metal material in the length direction. In FIG. 6, in order to make the semiconductor strain gauge 35 easier to understand, only the part corresponding to the semiconductor strain gauge 35 is illustrated in bold.

[0042] The semiconductor strain gauge 35 is made of, for example, polysilicon. The semiconductor strain gauge 35 is made of P-type polysilicon by injecting impurities into the polysilicon. Examples of the impurity elements include hydrogen, argon, phosphorus, and boron. The semiconductor strain gauge 35 is manufactured at the same time as the semiconductor layer (not shown) of the thin film transistor 40 is manufactured. However, the injection of impurities into the semiconductor strain gauge 35 and the injection of impurities into the semiconductor layer of the thin film transistor 40 are performed separately, and the semiconductor strain gauge 35 has a different impurity concentration from the semiconductor layer of the thin film transistor 40. In this embodiment, the semiconductor strain gauge 35 has an impurity concentration 30% higher than that of the semiconductor layer of the thin film transistor 40. Therefore, the semiconductor strain gauge 35 has a higher gauge factor and higher sensitivity than the case where the semiconductor strain gauge 35 has the same impurity concentration as the semiconductor layer of the thin film transistor 40.

[0043] The semiconductor strain gauge 35 is disposed in the connection portion 25 (deformation reduction region L2) of the vertical hinge portion 12A. Therefore, a load is unlikely to act on the semiconductor strain gauge 35, and damage to the semiconductor strain gauge 35 is suppressed.

[0044] In the present disclosure, the semiconductor strain gauge 35 may be disposed on the second strain gauge 33 instead of the first strain gauge 32. Alternatively, the semiconductor strain gauge 35 may be disposed on both the first strain gauge 32 and the second strain gauge 33. Moreover, it is desirable that the proportion of the semiconductor strain gauge 35 is within a range of 10% to 20% of the strain gauge 31 in the longitudinal direction.

[0045] 7, one end of the first strain gauge 32 (start end 31a of the strain gauge 31) is disposed in the first body portion 11a. One end of the second strain gauge 33 (end end 31b of the strain gauge 31) is disposed in the first body portion 11a.

[0046] 7, the thin film transistor 40 is disposed in the body portion 11. Thus, the thin film transistors 40 are arranged in a matrix in the first direction X and the second direction Y corresponding to the body portion 11. The thin film transistor 40 of the present embodiment is a top-gate type transistor.

[0047] Although not shown, the thin film transistor 40 includes a semiconductor layer, a gate insulating film laminated on the semiconductor layer, a gate electrode laminated on the gate insulating film, a source electrode laminated on a part of the semiconductor layer, and a drain electrode laminated on another part of the semiconductor layer. The gate insulating film is disposed between the source electrode and the drain electrode. The semiconductor layer is doped with impurities at a portion connected to the source electrode and the drain electrode, and has a predetermined impurity concentration. The start end 31a of the strain gauge 31 is connected to the source electrode of the thin film transistor 40. Hereinafter, the connection point between the thin film transistor 40 and the start end 31a of the strain gauge 31 is referred to as a first connection point P1.

[0048] The gate line 41 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 41 are disposed in the first direction X. The gate line 41 is connected to the gate electrodes of the thin film transistors 40. Thus, the thin film transistors 40 arranged in the second direction Y share one gate line 41.

[0049] 6, the first signal line 42 is disposed across the multiple vertical hinge portions 12A and the multiple body portions 11, and extends in the first direction X. Similarly, the second signal line 43 is disposed across the multiple vertical hinge portions 12A and the multiple body portions 11, and extends in the first direction. Although not particularly shown, the first signal line 42 and the second signal line 43 are disposed in multiple numbers in the second direction Y.

[0050] 7, the first signal line 42 is connected to the drain electrode of the thin film transistor 40 in each body portion 11. Therefore, the multiple thin film transistors arranged in the first direction X share one first signal line 42.

[0051] The first wiring 44 is a wiring arranged in the body part 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 a first intermediate point P2. The other end of the first wiring 44 is connected to a second signal line 43. Hereinafter, the connection point between the first wiring 44 and the second signal line 43 is referred to as a second connection point P3. In addition, the first wiring 44 is provided in each body part 11. Therefore, the multiple thin film transistors 40 arranged in the first direction X share one second signal line 43. In addition, a second resistor part 52 is provided on the first wiring 44.

[0052] 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 is a circuit parallel to the circuit consisting of the strain gauge 31 and the first wiring 50, with the start end 31a of the strain gauge 31 as a branch point. In addition, a third resistance portion 53 and a fourth resistance portion 54 are arranged in the second wiring 45. Hereinafter, a point on the second wiring 45 between the third resistance portion 53 and the fourth resistance portion 54 is referred to as a second intermediate point P4.

[0053] 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 disposed across the multiple horizontal hinge parts 12B and the multiple body parts, and extends in one direction of the second direction Y. The second potential detection line 56 is disposed across the multiple horizontal hinge parts 12B and the multiple body parts 11, and extends in the other direction of the second direction Y.

[0054] As described above, according to this embodiment, the circuit including the strain gauge 31 constitutes a Wheatstone bridge circuit, which will be described in detail below.

[0055] 8 is a diagram showing a Wheatstone bridge circuit of the embodiment. The second resistance value R2 of the second resistor 52, the third resistance value R3 of the third resistor 53, and the fourth resistance value R4 of the fourth resistor 54 are each the same as the first resistance value R1 of the strain gauge 31 when the hinge portion 12 is not modified (R1=R2=R3=R4). The second resistor 52, the third resistor 53, and the fourth resistor 54 are provided in the body portion 11. Therefore, even when the hinge portion 12 is deformed, the change in the resistance value is zero.

[0056] 8, when the strain gauge 31 detects the amount of strain, a detection signal having a predetermined first potential V1 is supplied to the first signal line 42. A second potential V2 lower than the first potential V1 (V2>V1) is supplied to the second signal line 43. In this embodiment, the second potential V2 is 0V. Therefore, when the thin film transistor 40 is closed, the potential of the first connection point P! (the start end 31a of the strain gauge 31) becomes the first potential V1.

[0057] When the hinge portion 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 portion 52, the third resistance value R3 of the third resistor portion 53, and the fourth resistance value R4 of the fourth resistor portion 54 are all equal. 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 all equal.

[0058] On the other hand, when the hinge portion 12 deforms and strain is generated in the strain gauge 31, the first resistance value R1 changes and the potential V3 at the first intermediate point P2 changes. Therefore, a potential difference occurs between the first intermediate point P2 and the second intermediate point P4. From the above, the amount of change in the resistance value of the strain gauge 31 can be detected by detecting the potentials V3 and V4.

[0059] As shown in FIG. 1, the array layer 30 has a connection portion 101 arranged in the peripheral region 6 for driving the load detection circuit, 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.

[0060] The connection portion 101 is for connecting to a driving IC (Integrated Circuit) arranged outside the stretchable device 100. The driving IC may be mounted as a COF (Chip On Film) on a flexible printed circuit board or a rigid board (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.

[0061] 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 a driving IC. The gate line driving circuit 102 selects the plurality of gate lines 41 sequentially or simultaneously, and supplies a gate driving signal to the selected gate lines 41.

[0062] The first signal line selection circuit 103 is a switch circuit that sequentially or simultaneously selects the multiple first signal lines 42. The first signal line selection circuit 103 connects the first signal lines 42 to the driving IC based on a selection signal supplied from the driving IC. As a result, a predetermined first potential V1 is applied to the first signal lines 42.

[0063] The second signal line selection circuit 104 is a switch circuit that sequentially or simultaneously selects the multiple second signal lines 43. The second signal line selection circuit 104 connects the second signal lines 43 to the driving IC based on a selection signal supplied from the driving IC. This causes a predetermined second potential V2 to be applied to the second signal lines 43. In this embodiment, the second potential V2 is 0V.

[0064] The first potential detection line selection circuit 105 is a switch circuit that sequentially or simultaneously selects the multiple 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. This causes the potential V3 of the first intermediate point P2 to be sent to the driving IC.

[0065] The second potential detection line selection circuit 106 is a switch circuit that sequentially or simultaneously selects the multiple 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. This causes the potential V4 of the second intermediate point P4 to be sent to the driving IC.

[0066] Although the embodiments have been described above, the present disclosure is not limited to the examples shown in the embodiments. For example, the semiconductor strain gauge 35 is disposed only in the connection portion 25 of the hinge portion 12, but the present disclosure may be disposed in a portion other than the connection portion 25. In other words, when the deformation amount reduction region L2 other than the connection portion 25 exists in the hinge portion 12, the semiconductor strain gauge 35 may be disposed in the deformation amount reduction region L2 other than the connection portion 25. In addition, the reason why the semiconductor strain gauge 35 is disposed in the deformation amount reduction region L2 is to suppress damage to the semiconductor strain gauge 35. Therefore, the present disclosure may be disposed in a portion other than the deformation amount reduction region L2, although the semiconductor strain gauge 35 is more likely to be damaged.

[0067] (Example) FIG. 9 is a diagram (graph) showing experimental data of the embodiment. Next, the embodiment will be described. In order to confirm the effect of the semiconductor strain gauge, five semiconductor strain gauges with different impurity concentrations were manufactured as samples. The impurity concentrations of the five semiconductor strain gauges were set to 0.16 times, 0.33 times, 0.5 times, 1 time, and 1.33 times the impurity concentration of the semiconductor layer of the thin film transistor as a reference. The semiconductor strain gauge showing an impurity concentration of 1.33 times is the embodiment, and the other semiconductor strain gauges are comparative examples. The gauge factor of each of the five semiconductor strain gauges was also determined. The implanted impurity was boron. The results of each gauge factor are shown in FIG. 9.

[0068] As shown in Figure 9, the semiconductor strain gauge with an impurity concentration of 1 (the same impurity concentration as the semiconductor layer of a thin-film transistor) showed a gauge factor of about 13.5. The gauge factors of the semiconductor strain gauges with impurity concentrations of 0.16, 0.33, and 0.5 were similar to or lower than the gauge factor of the semiconductor strain gauge with an impurity concentration of 1.

[0069] On the other hand, a semiconductor strain gauge with an impurity concentration of 1.33 times (an impurity concentration 30% higher than the semiconductor layer of a thin-film transistor) showed a gauge factor of about 18. In other words, it showed a significantly higher value than the gauge factor of a semiconductor strain gauge with an impurity concentration of 1. From the above, it was found that a highly sensitive semiconductor strain gauge can be obtained by making the impurity concentration of the semiconductor strain gauge higher than that of the thin-film transistor. [Explanation of symbols]

[0070] 10 Resin substrate 11 Body 12 Hinge part 19 Hole 20 Bend 25 Connection 30 Array Layer 31 Strain gauge 32 First strain gauge 33 Second strain gauge 34 Folded section 35 Semiconductor strain gauge 40 Thin-film transistor 41 Gate line 42 First signal line 43 Second signal line 44 1st wiring 45 2nd wiring 52 2nd resistance section 53 3rd resistance section 54 4th resistance section 55 First potential detection line 56 Second potential detection line 60 1st elastic resin 70 Second elastic resin 100 Stretchable Devices L2 Deformation reduction area P1 First connection point P2 1st intermediate point P3 Second connection point P4 2nd intermediate point

Claims

1. The laminate includes a first elastic resin, a resin substrate, an array layer, and a second elastic resin, which are laminated in this order. The resin substrate is A plurality of body parts; a plurality of hinge portions connecting the body portions to each other; having The array layer comprises: a plurality of thin film transistors disposed in the body portion; A plurality of strain gauges disposed in the hinge portion; having The strain gauge includes a semiconductor strain gauge formed of a semiconductor material in a portion of its length; The impurity concentration of the semiconductor strain gauge is higher than the impurity concentration of the thin film transistor. Stretchable device.

2. The impurity concentration of the semiconductor strain gauge is 30% or more higher than the impurity concentration of the thin film transistor. The stretchable device of claim 1.

3. The length of the semiconductor strain gauge is 10% to 20% of the length of the strain gauge.

3. A stretchable device according to claim 1 or 2.

4. the hinge portion has a deformation reduction region in which the deformation amount when a load is applied is 1% or less compared to a case in which no load is applied; The semiconductor strain gauge is disposed in the deformation reduction region.

3. A stretchable device according to claim 1 or 2.

5. the hinge portion has a deformation reduction region in which the deformation amount when a load is applied is 1% or less compared to a case in which no load is applied; The semiconductor strain gauge is disposed in the deformation reduction region. The stretchable device of claim 3.

6. The strain gauge comprises: a first strain gauge extending from one end to the other end in a longitudinal direction of the hinge portion; a second strain gauge extending from the other end to one end in the longitudinal direction of the hinge portion; a folded portion disposed at the other end of the hinge portion in the longitudinal direction and connecting the first strain gauge and the second strain gauge; Possesses 3. A stretchable device according to claim 1 or 2.

7. The strain gauge comprises: a first strain gauge extending from one end to the other end in a longitudinal direction of the hinge portion; a second strain gauge extending from the other end to one end in the longitudinal direction of the hinge portion; a folded portion disposed at the other end of the hinge portion in the longitudinal direction and connecting the first strain gauge and the second strain gauge; Possesses The stretchable device of claim 3.

8. The strain gauge comprises: a first strain gauge extending from one end to the other end in a longitudinal direction of the hinge portion; a second strain gauge extending from the other end to one end in the longitudinal direction of the hinge portion; a folded portion disposed at the other end of the hinge portion in the longitudinal direction and connecting the first strain gauge and the second strain gauge; Possesses 5. The stretchable device of claim 4.

9. The strain gauge comprises: a first strain gauge extending from one end to the other end in a longitudinal direction of the hinge portion; a second strain gauge extending from the other end to one end in the longitudinal direction of the hinge portion; a folded portion disposed at the other end of the hinge portion in the longitudinal direction and connecting the first strain gauge and the second strain gauge; Possesses 6. The stretchable device of claim 5.

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