Pressure Sensor

Abstract

To provide a pressure sensor that can detect a correct pressure value even when expanded and contracted.SOLUTION: A pressure sensor includes a resin substrate, an array substrate, a sensor layer, a common electrode, and a protection film. The array substrate includes a stretchable base material and an array layer. The stretchable base material has a plurality of first extension parts extending in a first direction parallel to the resin substrate, a plurality of second extension parts, and a plurality of main body parts provided at positions where the first extension parts and the second extension parts intersect. The array layer has a plurality of array layer branch parts stacked in the first extension parts or the second extension parts, and a plurality of array layer main body parts stacked on the main body parts. The array layer main body part has a first surface facing the common electrode, and an array electrode stacked on the first surface. The sensor layer has a plurality of divisional sensor layers divided in the first direction and a second direction. The divisional sensor layers are provided on the first surface and cover the array electrode.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a pressure sensor. [Background technology]

[0002] The pressure sensor includes an array substrate on which a plurality of array electrodes are provided, and a counter substrate that faces the array electrodes and supports a common electrode. The counter substrate is a base material to which pressure is input, and is sometimes called a protective film. In the patent document listed below, a sensor layer that covers the common electrode is provided on the surface of the counter substrate that faces the array electrodes. The sensor layer in the patent document listed below uses a conductive elastomer. The conductive elastomer is made of a rubber material, which is an insulator, mixed with a conductive material. Therefore, the electrical resistance of the conductive elastomer decreases when it is deformed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-44937 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, pressure sensors with surface stretchability (stretchable pressure sensors) have been proposed. In these pressure sensors, the array substrate and the counter substrate each stretch. However, when the sensor layer stretches in response to the expansion and contraction of the array substrate or the counter substrate, the resistance value of the sensor layer changes. This means that accurate pressure values ​​cannot be detected.

[0005] An object of the present invention is to provide a pressure sensor that can accurately detect a pressure value even when the sensor expands or contracts. [Means for solving the problem]

[0006] A pressure sensor according to a first aspect of the present disclosure includes a resin substrate, an array substrate, a sensor layer, a common electrode, and a protective film, which are laminated in this order. The array substrate includes a stretchable substrate laminated on the resin substrate, and an array layer laminated on the resin substrate via the stretchable substrate. The stretchable substrate includes: first extension portions extending in a first direction parallel to the resin substrate and arranged in a second direction parallel to the resin substrate and intersecting the first direction; second extension portions extending in the second direction and arranged in a plurality of directions in the first direction; and multiple main portions provided at intersections between the first extension portions and the second extension portions. The array layer includes multiple array layer branch portions laminated on the first extension portions or the second extension portions, and multiple array layer main portions laminated on the main portion. The array layer main portion has a first surface facing the common electrode and an array electrode laminated on the first surface. The sensor layer includes a plurality of divided sensor layers divided in the first direction and the second direction, the divided sensor layers being provided on the first surface and covering the array electrodes.

[0007] A pressure sensor according to a second aspect of the present disclosure includes a resin substrate, an array substrate, a sensor layer, a common electrode, and a protective film, which are laminated in this order. The array substrate includes a stretchable substrate laminated on the resin substrate, and an array layer laminated on the resin substrate via the stretchable substrate. The stretchable substrate includes: first extension portions extending in a first direction parallel to the resin substrate and arranged in a second direction parallel to the resin substrate and intersecting the first direction; second extension portions extending in the second direction and arranged in a plurality of directions in the first direction; and multiple main body portions provided at intersections between the first extension portions and the second extension portions. The array layer includes multiple array layer branch portions laminated on the first extension portions or the second extension portions, and multiple array layer main body portions laminated on the main body portions. The array layer main body has a first surface facing the common electrode, an array electrode laminated on the first surface, and an annular guard electrode laminated on the first surface to surround the array electrode and have the same potential as the array electrode. The sensor layer is provided on the plurality of array layer branch portions and the plurality of array layer main bodies, and covers the plurality of array electrodes and the plurality of annular guard electrodes. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view of a pressure sensor according to a first embodiment, viewed from the detection surface side. [Figure 2] FIG. 2 is a cross-sectional view schematically showing a cross section of the pressure sensor according to the first embodiment. [Figure 3] FIG. 3 is an enlarged plan view of a portion of the stretchable substrate placed in the detection area. [Figure 4] FIG. 4 is a plan view showing the state in which the array layer and the sensor layer are laminated on the main body of the stretchable substrate. [Figure 5] FIG. 5 is a circuit diagram showing the circuit configuration of the pressure sensor of the first embodiment. [Figure 6] FIG. 6 is a cross-sectional view of the pressure sensor of the first embodiment taken along line III-III in FIG. [Figure 7]FIG. 7 is a cross-sectional view of the pressure sensor of the first embodiment taken along line IV-IV in FIG. [Figure 8] FIG. 8 is a cross-sectional view showing the pressure sensor of the first embodiment when pressed. [Figure 9] FIG. 9 is a diagram showing steps of a method for manufacturing the pressure sensor 1 of the first embodiment. [Figure 10] FIG. 10 is a plan view of a divided sensor layer according to the first modification. [Figure 11] FIG. 11 is a plan view of the sensor layer, the array substrate, and part of the resin substrate in the pressure sensor of the second embodiment. [Figure 12] FIG. 12 is a cross-sectional view taken along line XII-XII in FIG. [Figure 13] 13 is a cross-sectional view taken along line XIII-XIII in FIG. [Figure 14] FIG. 14 is a cross-sectional view showing an example of a state in which the detection surface of the pressure sensor according to the second embodiment is pressed. [Figure 15] FIG. 15 is a cross-sectional view showing another example of a state in which the detection surface of the pressure sensor according to the second embodiment is pressed. [Figure 16] FIG. 16 is a diagram showing steps of a method for manufacturing the pressure sensor 1 of the second embodiment. [Figure 17] FIG. 17 is a plan view showing the sensor layer, the array substrate, and a part of the substrate as viewed from the common electrode in the pressure sensor of the second modification. [Figure 18] FIG. 18 is a cross-sectional view of the pressure sensor of the third modification, in which the first extending portion is cut in the second direction. [Figure 19] FIG. 19 is a plan view of the annular guard electrode of the pressure sensor of the third modification, viewed from the common electrode side. [Figure 20] FIG. 20 is a plan view of the annular guard electrode of the pressure sensor of the fourth modification, viewed from the common electrode side. [Figure 21] FIG. 21 is a plan view of the annular guard electrode of the pressure sensor of the fifth modification, viewed from the common electrode side. [Figure 22] FIG. 22 is a plan view of the annular guard electrode of the pressure sensor of the sixth modification, viewed from the common electrode side. [Figure 23] FIG. 23 is a cross-sectional view that schematically shows a cross section of the pressure sensor of the seventh modification. DETAILED DESCRIPTION OF THE INVENTION

[0009] Modes (embodiments) for implementing the pressure sensor of 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 make while maintaining the gist of the invention are naturally included within the scope of the present invention. For clarity of explanation, the drawings may show the width, thickness, shape, etc. of each part more schematically than 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 previously described with reference to the previous figures are designated by the same reference numerals, and detailed descriptions may be omitted as appropriate.

[0010] 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.

[0011] (Embodiment 1) Fig. 1 is a perspective view of a pressure sensor according to embodiment 1 as viewed from the detection surface side. As shown in Fig. 1, pressure sensor 1 is a plate-shaped device. One surface of pressure sensor 1 is detection surface 1a to which pressure is input. When viewed from the normal direction of detection surface 1a, pressure sensor 1 has a quadrangular shape.

[0012] The detection surface 1a of the pressure sensor 1 is divided into a detection area 2 where pressure can be detected, and a frame-shaped peripheral area 3 that surrounds the outside of the detection area 2. Note that in FIG. 1, a boundary line L1 is drawn to make it easier to understand the boundary between the detection area 2 and the peripheral area 3. The detection area 2 is divided into multiple individual detection areas 4. In other words, the detection area 2 is a collection of multiple individual detection areas 4.

[0013] The multiple individual detection areas 4 are arranged in a first direction Dx and a second direction Dy. The first direction Dx is a direction parallel to the detection surface 1a. The second direction Dy is a direction parallel to the detection surface 1a and intersects with the first direction Dx. In this embodiment, the first direction Dx is a direction parallel to the short side 1b of the pressure sensor 1. The second direction Dy is a direction parallel to the long side 1c of the pressure sensor 1. In other words, in this embodiment, the first direction Dx and the second direction Dy are perpendicular to each other. In addition, the normal direction (stacking direction) of the detection surface 1a is referred to as a third direction Dz.

[0014] Fig. 2 is a cross-sectional view schematically showing a cross section of the pressure sensor according to embodiment 1. As shown in Fig. 2, the pressure sensor 1 includes a resin substrate 5, an array substrate 6, a sensor layer 30, a common electrode 40, and a protective film 50, which are laminated in this order in the third direction Dz.

[0015] Hereinafter, the upper side or upward refers to one direction in the third direction Dz, and refers to the side where the array substrate 6 is arranged when viewed from the resin substrate 5. The lower side or downward refers to the other direction in the third direction Dz, and refers to the side where the resin substrate 5 is arranged when viewed from the array substrate 6. In addition, the view from above may be referred to as a planar view.

[0016] The resin substrate 5 is a base material of the pressure sensor 1. The resin substrate 5 has a quadrangular shape in a plan view. The resin substrate 5 is made of resin and has stretchability and flexibility.

[0017] The array substrate 6 includes a stretchable substrate 10 laminated on a resin substrate 5, and an array layer 20 laminated on the resin substrate 5 via the stretchable substrate 10. The stretchable substrate 10 is a thin film formed on the upper surface of the resin substrate 5. The stretchable substrate 10 has stretchability, flexibility, and insulating properties. The stretchable substrate 10 is made of a resin material such as polyimide.

[0018] Fig. 3 is an enlarged plan view of a portion of the stretchable substrate arranged in the detection area. As shown in Fig. 3, the stretchable substrate 10 has a plurality of first extension portions 11 extending in a first direction Dx in the detection area 2, a plurality of second extension portions 12 extending in a second direction Dy in the detection area 2, and a plurality of main body portions 13 provided at the intersections of the first extension portions 11 and the second extension portions 12.

[0019] A plurality of first extending portions 11 are arranged in the second direction Dy. Each first extending portion 11 is composed of a first arc portion 11a protruding in one direction in the second direction Dy and a second arc portion 11b protruding in the other direction in the second direction Dy. Note that the first extending portion 11 in this embodiment has two of either the first arc portion 11a or the second arc portion 11b and one of the other, for a total of three arc portions. Therefore, the first extending portion 11 extends in the first direction Dx while alternately bending in one direction and the other in the second direction Dy.

[0020] A plurality of second extension portions 12 are arranged in the first direction Dx. Each second extension portion 12 is composed of a third arc portion 12a that protrudes in one direction in the first direction Dx and a fourth arc portion 12b that protrudes in the other direction in the first direction Dx. Note that the second extension portion 12 in this embodiment has two of either the third arc portion 12a or the fourth arc portion 12b and one of the other, for a total of three arc portions. Therefore, the second extension portion 12 extends in the second direction Dy while alternately bending in one direction and the other in the first direction Dx.

[0021] 4 is a plan view of the main body 13 of the stretchable substrate, with the array layer and the sensor layer stacked thereon. As shown in FIG. 4, the main body 13 has a rectangular shape in plan view and has four corners. The main body 13 is arranged so that each of the four corners faces the first direction Dx and the second direction Dy. Each of the corners of the main body 13 merges with (connects to) the first extension 11 or the second extension 12.

[0022] Therefore, as shown in FIG. 3 , the stretchable substrate 10 has a plurality of cutouts 14 surrounded by the first extension portion 11 and the second extension portion 12. The cutouts 14 penetrate in the third direction Dz. The resin substrate 5 is exposed through the cutouts 14. With such a stretchable substrate 10, when a load is applied in the first direction Dx or the second direction Dy, the region of the cutouts 14, which has lower rigidity, deforms by expanding or contracting. In other words, the first extension portion 11 or the second extension portion 12 expands or contracts. Therefore, the main body portion 13 expands or contracts very little in the first direction Dx or the second direction Dy.

[0023] Additionally, the stretchable substrate 10 has a frame-shaped frame portion 15 extending along the peripheral region 3 (see FIG. 2, not shown in other figures). The inner periphery of the frame portion 15 is connected to the first extending portion 11 and the second extending portion 12. An adhesive layer 16 for adhering the protective film 50 is provided on the upper side of the frame portion 15. Note that in the present disclosure, the frame portion 15 and the protective film 50 may be adhered via a spacer.

[0024] The array layer 20 is laminated on the upper surface of the stretchable substrate 10. The array layer 20 has an array layer peripheral portion (not shown) laminated on the frame portion 15 of the stretchable substrate 10, array layer branch portions 20A (see FIG. 6) laminated on the first extension portion 11 or the second extension portion 12, and an array layer main portion 20B (see FIG. 7) laminated on the main portion 13. Note that a driving transistor 23 and an array electrode 25 are arranged in the array layer main portion 20B (see FIG. 7).

[0025] As shown in FIG. 1, in the peripheral area of ​​the array layer (not shown), a connection section 7, a gate line driving circuit 8, a signal line selection circuit 9, gate lines 21 (see FIG. 5), signal lines 22 (see FIG. 5), and common wiring 41 are provided.

[0026] The connection section 7, the gate line driving circuit 8, and the signal line selection circuit 9 are arranged in the peripheral region 3. The connection section 7 is for connecting to a driving IC (Integrated Circuit) arranged outside the pressure sensor 1. In the present disclosure, the driving IC may be mounted as a COF (Chip On Film) on a flexible printed circuit board or a rigid board connected to the connection section 7. Alternatively, the driving IC may be mounted as a COG (Chip On Glass) in the peripheral region 3 of the resin substrate 5.

[0027] The gate line driving circuit 8 is a circuit that drives a plurality of gate lines 21 (see FIG. 5) based on various control signals from the driving IC. The gate line driving circuit 8 sequentially or simultaneously selects the plurality of gate lines 21 (see FIG. 5) and supplies a gate driving signal to the selected gate lines 21. The signal line selection circuit 9 is a switch circuit that sequentially or simultaneously selects a plurality of signal lines 22 (see FIG. 5). The signal line selection circuit 9 is, for example, a multiplexer. Based on the selection signal supplied from the driving IC, the signal line selection circuit 9 connects the selected signal line 22 to the driving IC.

[0028] The common wiring 41 is a wiring for supplying a predetermined voltage to the common electrode 40, and extends along the peripheral region 3. The common wiring 41 is connected to a driving IC via a connection portion 7, and a constant voltage is supplied from the driving IC to the common wiring 41.

[0029] 5 is a circuit diagram showing the circuit configuration of the pressure sensor of embodiment 1. The gate lines 21 and the signal lines 22 are drawn from the peripheral region 3 (the gate line driving circuit 8 or the signal line selection circuit 9) into the detection region 2. As shown in FIG. 5, the gate lines 21 extend in the first direction Dx. A plurality of the gate lines 21 are arranged in the second direction Dy. The signal lines 22 extend in the second direction Dy. A plurality of the signal lines 22 are arranged in the first direction Dx.

[0030] The gate line 21 is stacked on the first extension portion 11 and main body portion 13 of the stretchable substrate 10 in the detection area 2, and extends in the first direction Dx. In other words, the gate line 21 includes a first gate line 21a (see FIG. 6) extending on the first extension portion 11, and a second gate line 21b (see FIG. 7) extending on the main body portion 13. Details will be described below.

[0031] Fig. 6 is a cross-sectional view of the pressure sensor of embodiment 1 taken along line VI-VI in Fig. 3. As shown in Fig. 6, the array layer branch portion 20A includes a first insulating layer 27 laminated on the upper surface of the first extension portion 11, a first gate line 21a laminated on the upper surface of the first insulating layer 27, and a third insulating layer 29 laminated on the upper surface of the first insulating layer 27 and the upper surface of the first gate line 21a. Thus, the first gate line 21a extends in the first direction Dx while meandering along the first extension portion 11. Furthermore, an end portion 21c of the first gate line 21a in the first direction Dx extends to the main body portion 13 (see Fig. 4).

[0032] 7 is a cross-sectional view of the pressure sensor of embodiment 1 taken along line VII-VII in FIG. 4. In FIG. 7, a boundary line L2 is drawn to facilitate understanding of the boundary between the array layer main body 20B (main body 13) and the array layer branch 20A (first extension 11). As shown in FIG. 7, the array layer main body 20B includes a second gate line 21b stacked between a first insulating layer 27 and a second insulating layer 28 and extending in the first direction Dx. An end 21d of the second gate line 21b is connected to an end 21c of the first gate line 21a via a contact layer 24. Thus, the first gate lines 21a and the second gate lines 21b are alternately connected to form the gate line 21.

[0033] The signal line 22 is laminated on the second extension portion 12 and the main body portion 13 of the stretchable substrate 10 within the detection area 2, and extends in the second direction Dy. In other words, the signal line 22 includes a first signal line 22a (see FIG. 4) extending on the second extension portion 12, and a second signal line 22b (see FIG. 7) extending on the main body portion 13.

[0034] Although not specifically shown, the first signal line 22a, like the first gate line 21a, is laminated between the first insulating layer 27 and the third insulating layer 29 that are laminated on the upper side of the second extending portion 12. Therefore, the first signal line 22a extends in the second direction Dy while meandering along the second extending portion 12. In addition, an end portion 22c of the first signal line 22a extends to the main body portion 13 (see FIG. 4).

[0035] 7, the second signal line 22b is laminated between the main body 13 and the first insulating layer 27 and extends in the second direction Dy. An end of the second signal line 22b is connected to an end 22c of the first signal line 22a via a contact layer (not shown). Thus, the first signal line 22a and the second signal line 22b are alternately connected to form the signal line 22.

[0036] The array layer main body 20B has, stacked in this order on the upper surface of the main body 13, a second signal line 22b, a first insulating layer 27, a second gate line 21b, a second insulating layer 28, a driving transistor 23, a third insulating layer 29, and an array electrode 25. The upper surface of the third insulating layer 29 is called the first surface 20a of the array layer 20 (array substrate 6), and is flattened.

[0037] The driving transistor 23 includes a semiconductor layer 23a, a gate insulating film 23b, a gate electrode 23c, a drain electrode 23d, and a source electrode 23e. The source electrode 23e is electrically connected to the array electrode 25. The gate electrode 23c is connected to the gate line 21 via a contact layer 23f. The drain electrode 23d is connected to the signal line 22 via a contact layer (not shown). Therefore, when the gate line 21 is scanned, the array electrode 25 and the signal line 22 are electrically connected. Then, the electrical signal (current value) input to the array electrode 25 is obtained via the signal line 22.

[0038] The sensor layer 30 is a conductive elastomer in which a conductive material is mixed with an insulating rubber material (base material). The sensor layer 30 has a high resistance when no pressure is applied. When pressure is applied to the sensor layer 30, the microparticles in the rubber material come into contact or proximity with each other, reducing the resistance of the sensor layer 30. Furthermore, as the deformation of the rubber material increases, the amount of contact between the microparticles increases, significantly reducing the resistance of the sensor layer 30.

[0039] 2, the sensor layer 30 is laminated on the first surface 20a of the array layer 20. The sensor layer 30 has a plurality of divided sensor layers 31 divided in the first direction Dx and the second direction Dy. The number of divided sensor layers 31 is the same as the number of array electrodes 25, and they are adhered to the first surface 20a by adhesive.

[0040] 4, the divided sensor layer 31 has a sensor layer main body portion 32 laminated on the array layer main body portion 20B, and a sensor layer extension portion 33 extending (expanding) from the array layer main body portion 20B toward the array layer branch portion 20A. The sensor layer main body portion 32 has a rectangular shape.

[0041] 7, the sensor layer main body 32 covers the array electrodes 25 from above and is in contact with the array electrodes 25. The sensor layer main body 32 is spaced apart from the common electrode 40 disposed above it. Thus, the sensor layer main body 32 is electrically connected to the array electrodes 25 and insulated from the common electrode 40. The sensor layer extension 33 is a portion that extends from the sensor layer main body 32 in the first direction Dx or the second direction Dy. This increases the adhesive area between the sensor layer 30 and the array layer 20, improving the fixing strength of the sensor layer 30.

[0042] The protective film 50 is a resin base material that is stretchable, flexible, and insulating. As shown in Fig. 7, the protective film 50 has a facing surface 51 facing downward and facing the sensor layer 30, and a detection surface 1a facing upward.

[0043] The common electrode 40 is a solid film provided on the opposing surface 51. The common electrode 40 may be a conductive layer containing multiple metal files inside a base material (resin), or a conductive layer in which multiple silver nanofibers are layered inside a base material (resin). A predetermined voltage is applied to the common electrode 40 via a common wiring 41.

[0044] 8 is a cross-sectional view showing the pressure sensor of embodiment 1 when pressed. Next, a method of using the pressure sensor 1 will be described. When the detection surface 1a of the pressure sensor 1 is pressed by a finger 200, a portion of the protective film 50 deforms so as to protrude downward. This brings the common electrode 40 into contact with the sensor layer 30. As a result, the common electrode 40 and the array electrode 25 are electrically connected. A current flows from the common electrode 40 to the array electrode 25 (see arrow A in FIG. 8). The current value input to the array electrode 25 is then output from the signal line 22.

[0045] Furthermore, when an expansion / contraction load acts on the pressure sensor 1 in the first direction Dx or the second direction Dy, a load in the first direction Dx or the second direction Dy acts on the resin substrate 5. Accordingly, a load in the first direction Dx or the second direction Dy also acts on the stretchable substrate 10 laminated on the resin substrate 5. Furthermore, the stretchable substrate 10 of this embodiment is provided with a lightening portion 14, and portions with low rigidity expand and contract. Therefore, the first extension portion 11 or the second extension portion 12 expands and contracts (see arrow B in FIG. 8). In other words, the amount of expansion and contraction of the main body portion 13 is extremely small.

[0046] Therefore, the deformation amount of the array layer main body portion 20B and the sensor layer main body portion 32 stacked on the main body portion 13 is also extremely small. In other words, the divided sensor layer 31 (sensor layer main body portion 32) is not deformed (the resistance value does not change) by the expansion and contraction load in the first direction Dx or the second direction Dy. Therefore, an accurate pressure value can be detected.

[0047] Although the sensor layer extension portion 33 of this embodiment is laminated on the first extension portion 11 or the second extension portion 12, the laminated length is relatively short. Therefore, the sensor layer extension portion 33 does not expand or contract (deform) following the first extension portion 11 or the second extension portion 12. Therefore, the resistance value of the sensor layer extension portion 33 does not change.

[0048] Furthermore, each divided sensor layer 31 is separated from and insulated from the adjacent divided sensor layer 31. This prevents current from flowing to the adjacent array electrode 25 via the sensor layer 30 (see dashed arrow C in FIG. 8).

[0049] 9 is a diagram showing steps in a method for manufacturing the pressure sensor 1 of embodiment 1. As shown in Fig. 9, the method for manufacturing the pressure sensor 1 of embodiment 1 includes an array substrate manufacturing step S1, a first transfer step S2 of transferring to a transfer material, a second transfer step S3 of transferring to a resin substrate 5, a sensor layer lamination step S4 of laminating the sensor layer 30, and an integration step S5 of integrating the substrate and the protective film. Note that the shape of the stretchable substrate 10 in Fig. 9 is abstracted.

[0050] The array substrate manufacturing process S1 is a process for manufacturing an array substrate 6 on a glass substrate 201. In detail, first, a film of the material of the stretchable substrate 10 (e.g., polyimide) is formed on the glass substrate 201. Next, each layer of the array layer 20 (including the array electrodes 25) is formed on the stretchable substrate 10. After that, etching is performed from above the array layer 20 to form the cutout portions 14 of the stretchable substrate 10. Note that, according to this process, the array layer branch portions 20A and the array layer main body portion 20B are also formed at the same time as the cutout portions 14 are formed.

[0051] The first transfer step S2 is a step of transferring the array substrate 6 from the glass substrate 201 to a transfer material 202. The transfer material 202 may be an adhesive tape. In this step, the transfer material 202 is first placed on top of the array substrate 6, and the upper surface of the array substrate 6 is adhered to the transfer material 202. Next, the transfer material 202 is peeled off, and the array substrate 6 is thereby transferred to the transfer material 202.

[0052] The second transfer step S3 is a step of transferring the array substrate 6 from the transfer material 202 to the resin substrate 5. An adhesive (not shown) is applied to the resin substrate 5. Thus, the array substrate 6 is bonded to the resin substrate 5 in this step.

[0053] The sensor layer lamination step S4 is a step of laminating the sensor layer 30 (divided sensor layers 31) on the array layer main body portion 20B. In Fig. 9, the divided sensor layers 31 are shown in a square shape for ease of viewing. The divided sensor layers 31 are fixed to the array layer main body portion 20B by adhesive.

[0054] In the integration process S5, an adhesive layer (not shown) is applied to the peripheral region 3 of the array substrate 6. Next, the adhesive layer is placed over the edge of the protective film 50 on which the common electrode 40 has been previously formed. When the adhesive layer hardens, the layers are integrated together. This completes the manufacturing process of the pressure sensor 1.

[0055] Although the pressure sensor 1 of the first embodiment has been described above, the present disclosure is not limited to the example of the first embodiment. The divided sensor layer 31 of the first embodiment has the sensor layer extension portion 33 in addition to the sensor layer main body portion 32, but the present disclosure may also be a divided sensor layer consisting only of the sensor layer main body portion. Furthermore, the upper surface of the sensor layer 30 of the embodiment is flat, but the sensor layer may have protrusions that protrude toward the common electrode, and the present disclosure is not limited to the shape of the sensor layer.

[0056] FIG. 10 is a plan view of a divided sensor layer according to Modification 1. Although the divided sensor layer 31 of Embodiment 1 is laminated on the first surface 20a of the array layer 20, the present disclosure is not limited thereto. For example, as shown in FIG. 10, the divided sensor layer 31A of Modification 1 has a rectangular shape in a plan view. The divided sensor layer 31A has a sensor layer main body 32, a sensor layer extension 33, and a sensor layer protrusion 34 that protrudes from the array layer 20 in a plan view. The sensor layer protrusion 34 is laminated on the upper surface of the resin substrate 5. This increases the adhesive area and the fixing force of the divided sensor layer 31A. Next, a pressure sensor according to Embodiment 2 will be described. The following description will focus on the differences from Embodiment 1.

[0057] (Embodiment 2) Fig. 11 is a plan view of a sensor layer, an array substrate, and a portion of a resin substrate in a pressure sensor of embodiment 2. Fig. 12 is a cross-sectional view taken along line XII-XII in Fig. 11. Fig. 13 is a cross-sectional view taken along line XIII-XIII in Fig. 11. As shown in Fig. 11, pressure sensor 1B of embodiment 2 differs from embodiment 1 in that it includes a guard electrode 60. Pressure sensor 1B of embodiment 2 also differs from embodiment 1 in that it includes a sensor layer 30B instead of sensor layer 30.

[0058] The guard electrode 60 is made of a conductive material and includes a plurality of annular guard electrodes 61 laminated on the array layer main body 20B and a plurality of connection guard electrodes 62 laminated on the array layer branch 20A.

[0059] The annular guard electrode 61 has an annular shape. In this embodiment, the annular guard electrode 61 has a rectangular frame shape in a plan view. The array electrode 25 is arranged on the inner circumferential side of the annular guard electrode 61. As shown in FIG. 12 , the annular guard electrode 61 is laminated on the first surface 20a of the array layer 20. In other words, the annular guard electrode 61 and the array electrode 25 are arranged in the same layer.

[0060] As shown in FIG. 11, the connection guard electrode 62 extends in the first direction Dx or the second direction Dy while meandering along the array layer branch portion 20A (the first extension portion 11 or the second extension portion 12). As shown in FIG. 13, the connection guard electrode 62 is stacked on the first surface 20a of the array layer 20. As shown in FIG. 12, the end portion 62a of the connection guard electrode 62 extends to the array layer main body portion 20B. The end portion 62a of the connection guard electrode 62 is connected to the annular guard electrode 61. Therefore, the connection guard electrode 62 connects the annular guard electrodes 61 adjacent to each other in the first direction Dx or the second direction Dy.

[0061] Although not specifically shown, the connection guard electrodes 62 that are arranged on the edge of the detection region 2 extend into the peripheral region 3 and are connected to guard electrode wiring (not shown). The guard electrode wiring is wiring for supplying a predetermined voltage to the annular guard electrode 61. The guard electrode wiring (not shown) is connected to a driving IC via a connection portion 7, and a predetermined voltage is supplied from the driving IC. When the pressure sensor 1B is in use, a voltage that is the same potential as that of the array electrode 25 is applied to the annular guard electrode 61 via the guard electrode wiring (not shown).

[0062] 11, the sensor layer 30B has a sensor layer main body 32 laminated on the array layer main body 20B, and a sensor layer connection portion 35 laminated on the array layer branch portion 20A. As shown in FIG. 12, the sensor layer main body 32 is laminated on the first surface 20a of the array layer 20, as in the first embodiment, and covers the array electrode 25. In the second embodiment, the sensor layer main body 32 covers the annular guard electrode 61 and is in contact with the annular guard electrode 61.

[0063] 11, the sensor layer connection portion 35 extends in the first direction Dx or the second direction Dy while meandering along the array layer branch portion 20A (the first extension portion 11 or the second extension portion 12). As shown in FIG. 13, the sensor layer connection portion 35 is laminated on the first surface 20a of the array layer 20 and covers the connection guard electrode 62. The sensor layer connection portion 35 also connects the sensor layer main bodies 32 adjacent to each other in the first direction Dx or the second direction Dy (see FIG. 14). As described above, the sensor layer 30B of the second embodiment has a plurality of sensor layer main bodies 32 and a plurality of sensor layer connection portions 35 integrated together.

[0064] 14 is a cross-sectional view showing an example of a state in which the detection surface of the pressure sensor of embodiment 2 is pressed. Next, a case in which a portion of the detection surface 1a of the pressure sensor 1B is pressed will be described. In the following description, the array electrode 25 that overlaps the pressed portion in the third direction Dz will be referred to as the pressed array electrode 25A, and the array electrode adjacent to the pressed array electrode 25A will be referred to as the adjacent array electrode 25B.

[0065] 14, when the detection surface 1a of the pressure sensor 1B is pressed by a finger 200, the common electrode 40 comes into contact with the sensor layer 30. Here, when the press-down array electrode 25A is connected to the signal line 22 (when the drive transistor 23 is ON), the press-down array electrode 25A and the common electrode 40 are electrically connected. Therefore, a current flows through the press-down array electrode 25A (see arrow D in FIG. 14).

[0066] Furthermore, the annular guard electrode 61 surrounding the press-down array electrode 25A is at the same potential as the press-down array electrode 25A. Therefore, current also flows through the annular guard electrode 61 surrounding the press-down array electrode 25A (see arrow E in FIG. 14). This prevents current from flowing from the common electrode 40 outside the annular guard electrode 61. In other words, this prevents current from flowing from the common electrode 40 through the sensor layer connection portion 35 to the adjacent array electrode 25B (see dashed arrow F in FIG. 14).

[0067] Fig. 15 is a cross-sectional view showing another example of a state in which the detection surface of the pressure sensor of embodiment 2 is pressed. Also, as shown in Fig. 15, when the press-down array electrode 25A is not connected to the signal line 22 (when the drive transistor 23 is OFF), the press-down array electrode 25A and the common electrode 40 are not electrically connected. Therefore, no current flows through the press-down array electrode 25A.

[0068] On the other hand, when the adjacent array electrode 25B is connected to the signal line 22 (when the drive transistor 23 is ON), there is a possibility that the current that has passed through the sensor layer connection portion 35 will flow to the adjacent array electrode 25B (see dashed arrow H in FIG. 15). However, an annular guard electrode 61 that surrounds the pressed array electrode 25A is disposed between the common electrode 40 and the adjacent array electrode 25B. Therefore, the current flowing from the common electrode 40 will flow toward the annular guard electrode 61 (see arrow G in FIG. 15) and will not flow to the adjacent array electrode 25B.

[0069] Therefore, in the pressure sensor 1 of embodiment 2, although each array electrode 25 is electrically connected by the sensor layer 30B, crosstalk does not occur. Furthermore, in embodiment 2, when an expansion / contraction load acts on the pressure sensor 1B in the first direction Dx or the second direction Dy, the first extension portion 11 or the second extension portion 12 expands or contracts, as in embodiment 1. Therefore, the amount of deformation of the sensor layer main body 32 is also extremely small, and the resistance value of the sensor layer main body 32 does not change. Therefore, an accurate pressure value can be detected.

[0070] When the pressure sensor 1B expands or contracts, the sensor layer connection portion 35 deforms in accordance with the expansion or contraction of the first extension portion 11 or the second extension portion 12. If the common electrode 40 comes into contact with the sensor layer connection portion 35, there is a possibility that current will pass through the sensor layer connection portion 35 and flow toward the array electrode 25. However, current flowing toward the array electrode 25 flows through the annular guard electrode 61. Therefore, even if a portion of the detection surface 1a that overlaps with the sensor layer connection portion 35 is pressed, no current will flow through the array electrode 25. In other words, an erroneous electrical signal (current) is prevented from being input to the array electrode 25.

[0071] Fig. 16 is a diagram showing steps of a method for manufacturing the pressure sensor 1 of embodiment 2. As shown in Fig. 16, the method for manufacturing the pressure sensor 1B of embodiment 2 includes a laminate manufacturing step S11, a sensor layer laminating step S12, a molding step S13, a first transfer step S14, a second transfer step S15, and an integration step S16. Note that the shape of the stretchable substrate 10 in Fig. 16 is abstracted.

[0072] The laminate manufacturing process S11 is a process for manufacturing a laminate 203 by depositing each layer constituting the array substrate 6 (stretchable substrate 10 and array layer 20) on a glass substrate 201. The deposition is performed as a solid film on the glass substrate 201. In this process, only the shape of the array electrodes 25 is formed by etching or the like.

[0073] In the sensor layer lamination step S12, a sensor layer 30B in the form of a solid film is laminated on the laminate 203 (on the array electrode 25). In this step, a pre-fabricated sensor layer 30B in the form of a solid film may be laminated on the laminate 203 and fixed by adhesive. Alternatively, the sensor layer 30B may be formed by applying raw materials for the sensor layer 30B onto the laminate 203.

[0074] In the molding process S13, etching is performed from above the solid sensor layer 30B to form the hollowed-out portions 14 of the stretchable substrate 10. This also forms the array layer branch portions 20A and the array layer main body portion 20B. In addition, the sensor layer main body portion 32 and the sensor layer connecting portion 35 are also formed. In other words, an array substrate 6 on which the sensor layer 30B is laminated is manufactured.

[0075] The first transfer step S14 is a step of transferring the array substrate 6 from the glass substrate 201 to the transfer material 202.

[0076] The second transfer step S15 is a step of transferring the array substrate 6 from the transfer material 202 to the resin substrate 5. An adhesive (not shown) is applied to the resin substrate 5. Thus, the array substrate 6 is bonded to the resin substrate 5 in this step.

[0077] In the integration step S16, an adhesive layer (not shown) is applied to the peripheral region 3 of the array substrate 6. Next, the adhesive layer is placed over the edge of the protective film 50 on which the common electrode 40 has been previously formed. When the adhesive layer hardens, the layers are integrated together. This completes the manufacturing process for the pressure sensor 1B.

[0078] The pressure sensor 1 of the second embodiment has been described above, but the present disclosure is not limited to the example of the first embodiment. For example, the annular guard electrode has a rectangular frame shape, but the annular guard electrode of the present disclosure may have a circular frame shape, and is not particularly limited. Below, a modified example of the second embodiment will be described.

[0079] (Variation 2) 17 is a plan view showing the sensor layer, array substrate, and part of the substrate as seen from the common electrode in the pressure sensor of Modification 2. As shown in Fig. 17, the sensor layer 30C of Modification 2 differs from that of Embodiment 2 in that it is a solid film. That is, the sensor layer 30C covers the array layer 20 and the part of the resin substrate 5 that is exposed from the cutout portion 14. Even in this sensor layer 30C, the annular guard electrode 61 is provided, thereby avoiding crosstalk.

[0080] (Variation 3) Fig. 18 is a cross-sectional view of the pressure sensor of Modification 3, cutting the first extension portion in the second direction. Fig. 19 is a plan view of the annular guard electrode of the pressure sensor of Modification 3, viewed from the common electrode side. The connection guard electrode 62D of Modification 3 differs from that of Embodiment 2 in that it is disposed on the upper surface of the first insulating layer 27. The connection guard electrode 62D of Modification 3 is formed in the same layer as the first gate line 21a and the first signal line 22a (not shown in Fig. 18). Therefore, the connection guard electrode 62D can be formed on the first insulating layer 27 simultaneously with the first gate line 21a and the first signal line 22a, facilitating manufacturing.

[0081] 19, only the annular guard electrode 61 is disposed on the first surface 20a of the array layer 20. Therefore, in the third modification, a contact hole (not shown) is formed in the array layer main body 20B. The connection guard electrode 62D and the annular guard electrode 61 are connected by a contact layer (not shown) filled in the contact hole. In other words, in the present disclosure, the connection guard electrode 62D does not need to be in the same layer as the annular guard electrode 61.

[0082] (Variation 4) 20 is a plan view of the annular guard electrode of the pressure sensor of Modification 4, viewed from the common electrode. The guard electrode 60E of Modification 4 differs from Modification 3 in that there are two (plural) annular guard electrodes 61 centered around the array electrode 25. The two annular guard electrodes 61 are a first annular guard electrode 61a that surrounds the outside of the array electrode 25, and a second annular guard electrode 61b that surrounds the outer periphery of the first annular guard electrode 61a. The first annular guard electrode 61a and the second annular guard electrode 61b may be collectively referred to as a multiple guard electrode.

[0083] The first annular guard electrode 61a and the second annular guard electrode 61b are narrower than the annular guard electrode 61 of Modification 1. Although not shown, the array layer main body 20B is provided with a contact layer connecting the first annular guard electrode 61a and the connection guard electrode 62D (not shown in FIG. 20, see FIG. 18) and a contact layer (not shown) connecting the second annular guard electrode 61b and the connection guard electrode 62D. Therefore, the first annular guard electrode 61a and the second annular guard electrode 61b are connected in parallel to the connection guard electrode 62D. According to Modification 4, even if one of the two annular guard electrodes 61 is separated, the remaining one functions as the annular guard electrode 61. Therefore, crosstalk can be reliably avoided. Although Modification 4 has exemplified an example in which two annular guard electrodes are provided, the present disclosure may provide three or more annular guard electrodes.

[0084] (Variation 5) 21 is a plan view of the annular guard electrode of the pressure sensor of Modification 5, viewed from the common electrode. The guard electrode 60F of Modification 5 differs from Modification 4 in that it includes a linking guard electrode 63 that links the first annular guard electrode 61a and the second annular guard electrode 61b. Furthermore, in Modification 5, the connecting guard electrode 62D (not shown in FIG. 21; see FIG. 18) is connected to the linking guard electrode 63 via a contact layer (not shown). Therefore, a predetermined voltage is supplied to the first annular guard electrode 61a and the second annular guard electrode 61b via the linking guard electrode 63. Modification 5 eliminates the need to provide a contact layer for each annular guard electrode 61, facilitating manufacturing.

[0085] (Variation 6) 22 is a plan view of the annular guard electrode of the pressure sensor of Modification 6, viewed from the common electrode. The guard electrode 60G of Modification 6 differs from Modification 5 in that a connection guard electrode 62G is provided on the first surface 20a of the array layer 20. An end of the connection guard electrode 62G is connected to the second annular guard electrode 61b. The linking guard electrode 63G connects the corners of the first annular guard electrode 61a and the second annular guard electrode 61b. According to Modification 6, the guard electrodes 60G are arranged in the same layer, allowing them to be deposited simultaneously.

[0086] FIG. 23 is a cross-sectional view schematically illustrating a cross section of a pressure sensor according to Modification 7. While each embodiment and each modification have been described above, the overall structure of the pressure sensor according to the present disclosure is not limited to the example described in Embodiment 1 (see FIG. 2). In the present disclosure, as shown in FIG. 23, a resin substrate 5 having an array substrate 6 bonded thereto is bonded to a separately formed housing 82. Alternatively, the housing 82 and the protective film 50 may be joined together using a frame-shaped spacer 81. According to this pressure sensor 1H, the pressure sensor can be formed in a separate process from the housing 82. Furthermore, in the present disclosure, the object to which the resin substrate 5 having the array substrate 6, the housing 82, and the protective film 50 are joined (attached) may be something other than the housing 82. [Explanation of symbols]

[0087] 1. 1H pressure sensor 1a Detection surface 2. Detection Area 3. Surrounding Areas 4 Individual detection areas 5 Resin substrate 6 Array board 10 Stretchable substrate 20 Array Layer 20A Array layer branch 20B Array layer main body 20a Page 1 21 Gate line 22 Signal line 23 Drive transistor 25 Array Electrodes 30, 30B, 30C sensor layer 31 divided sensor layer 32 Sensor layer main body 33 Sensor layer extension 40 common electrode 50 Protective film 60, 60E, 60F Guard electrode 61 Annular guard electrode 62, 62D, 62G Connection guard electrode 63 Connected guard electrode 61a First annular guard electrode 61b Second annular guard electrode

Claims

1. The device includes a resin substrate, an array substrate, a sensor layer, a common electrode, and a protective film, which are laminated in this order; The array substrate comprises: a stretchable substrate laminated on the resin substrate; an array layer laminated on the resin substrate via the stretchable base material; and The stretchable substrate is a plurality of first extending portions extending in a first direction parallel to the resin substrate and provided in a second direction parallel to the resin substrate and intersecting the first direction; a plurality of second extending portions extending in the second direction and provided in the first direction; a plurality of main body portions provided at an intersection of the first extension portion and the second extension portion; and The array layer comprises: a plurality of array layer branch portions stacked on the first extension portion or the second extension portion; a plurality of array layer main bodies stacked on the main body; and The array layer main body portion is a first surface facing the common electrode; an array electrode laminated on the first surface; an annular guard electrode laminated on the first surface, surrounding the array electrode, and at the same potential as the array electrode; and The sensor layer is provided on the plurality of array layer branch portions and the plurality of array layer main portions, and covers the plurality of array electrodes and the plurality of annular guard electrodes. Pressure sensor.

2. the first extension portion extends in the first direction while alternately bending in one direction and the other direction in the second direction, The second extending portion extends in the second direction while alternately bending in one direction and in the other direction in the first direction. The pressure sensor according to claim 1 .

3. a region surrounded by the first extension portion and the second extension portion is a lightening portion that exposes a part of the resin substrate; The sensor layer is a solid film that also covers the resin substrate through the lightening portion. The pressure sensor according to claim 1 or 2.

4. A plurality of the annular guard electrodes are provided around one of the array electrodes. The pressure sensor according to any one of claims 1 to 3.

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