Method for manufacturing pressure sensors

Abstract

The present invention provides a method for manufacturing a pressure sensor that can suppress a decrease in reliability. [Solution] A method for manufacturing a pressure sensor, comprising: forming a transistor on a support substrate; forming an insulating layer covering the transistor; forming a detection electrode connected to the transistor and a common electrode on the insulating layer; and forming a pressure-sensitive layer on the detection electrode by applying a pressure-sensitive layer material by printing.

Description

【Technical Field】 【0001】 Embodiments of the present invention relate to a method for manufacturing a pressure sensor. 【Background Art】 【0002】 Various pressure sensors capable of detecting a pressure distribution have been proposed. In such pressure sensors, a manufacturing method capable of suppressing a decrease in reliability has been demanded. 【Summary of the Invention】 【Problems to be Solved by the Invention】 【0003】 An object of the present embodiment is to provide a method for manufacturing a pressure sensor capable of suppressing a decrease in reliability. 【Means for Solving the Problems】 【0004】 According to one embodiment, a method for manufacturing a pressure sensor includes forming a transistor above a support substrate, forming an insulating layer covering the transistor, forming a detection electrode connected to the transistor and a common electrode on the insulating layer, and forming a pressure-sensitive layer by applying a pressure-sensitive layer material on the detection electrode by a printing method. 【0005】 According to one embodiment, a method for manufacturing a pressure sensor includes forming a transistor above a support substrate, forming an insulating layer covering the transistor, forming a detection electrode connected to the transistor on the insulating layer, forming a pressure-sensitive layer by applying a pressure-sensitive layer material on the detection electrode by a printing method, and forming a common electrode on the pressure-sensitive layer. 【Brief Description of Drawings】 【0006】 [Figure 1] FIG. 1 is a plan view showing a configuration example of a pressure sensor according to the first embodiment. [Figure 2] FIG. 2 is a plan view showing a configuration example of the pressure sensor shown in FIG. 1. [Figure 3]Figure 3 is a schematic cross-sectional view of the pressure sensor along the line III-III in Figure 2. [Figure 4] Figure 4 is a circuit diagram showing an example of the circuit configuration of the pressure sensor shown in Figure 1. [Figure 5] Figure 5 is a cross-sectional view illustrating the state in which the input surface of the pressure sensor shown in Figure 1 is pressed. [Figure 6] Figure 6 is a diagram illustrating an example of a manufacturing method for the pressure sensor shown in Figure 2. [Figure 7] Figure 7 is a diagram illustrating an example of a manufacturing method for the pressure sensor shown in Figure 2. [Figure 8] Figure 8 is a diagram illustrating an example of a manufacturing method for the pressure sensor shown in Figure 2. [Figure 9] Figure 9 is a plan view showing one example configuration of a pressure sensor according to the second embodiment. [Figure 10] Figure 10 is a schematic cross-sectional view of the pressure sensor along line XX in Figure 9. [Figure 11] Figure 11 is a diagram illustrating an example of a manufacturing method for the pressure sensor shown in Figure 9. [Figure 12] Figure 12 is a diagram illustrating an example of a manufacturing method for the pressure sensor shown in Figure 9. [Figure 13] Figure 13 is a diagram illustrating an example of a manufacturing method for the pressure sensor shown in Figure 9. [Modes for carrying out the invention] 【0007】 Hereinafter, this embodiment will be described with reference to the drawings. It should be noted that the disclosure is merely an example, and any modifications that a person skilled in the art could easily conceive while maintaining the spirit of the invention are naturally included within the scope of the present invention. Furthermore, the drawings may schematically represent the width, thickness, shape, etc., of each part compared to the actual embodiment in order to clarify the explanation; however, these are merely examples and do not limit the interpretation of the present invention. In addition, in this specification and in each drawing, components that perform the same or similar functions as those described above in previously shown drawings are denoted by the same reference numerals, and redundant detailed explanations may be omitted as appropriate. 【0008】 Figure 1 is a plan view showing one example configuration of the pressure sensor 1 of this embodiment. In this example, the first direction X, the second direction Y, and the third direction Z are orthogonal to each other, but they may intersect at angles other than 90 degrees. The first direction X and the second direction Y correspond to directions parallel to the main surface of the substrate constituting the pressure sensor 1, and the third direction Z corresponds to the thickness direction of the pressure sensor 1. In this specification, the direction from the substrate 10 toward the protective layer 90 is referred to as the "upper side" (or simply "up"), and the direction from the protective layer 90 toward the substrate 10 is referred to as the "lower side" (or simply "down"). When referring to the "second member above the first member" and the "second member below the first member," the second member may be in contact with the first member or separated from the first member. Furthermore, it is assumed that there is an observation position for observing the pressure sensor 1 on the tip side of the arrow indicating the third direction Z, and viewing from this observation position toward the XY plane defined by the first direction X and the second direction Y is called a plan view. 【0009】 In this embodiment, the pressure sensor 1 is a pressure distribution sensor. The pressure sensor 1 includes a substrate 10. The substrate 10 is formed in the shape of a flat plate parallel to the XY plane. In plan view, the substrate 10 has, for example, a rectangular shape. 【0010】 In the example shown in Figure 1, the pressure sensor 1 is equipped with a protective layer 90. The protective layer 90 is formed in the shape of a flat plate parallel to the XY plane. The substrate 10 and the protective layer 90 are superimposed in a plan view. 【0011】 The pressure sensor 1 has an input surface 1a on one of its surfaces to which pressure is applied. In the example shown in Figure 1, the pressure sensor 1 has the input surface 1a on the surface of the protective layer 90 opposite to the surface facing the substrate 10. The pressure sensor 1 detects the pressure applied to the input surface 1a. 【0012】 The input surface 1a, in a plan view, includes a detection unit 2 for detecting pressure and a frame-shaped non-detection unit 3 surrounding the detection unit 2. The detection unit 2 includes multiple detection regions R. In the example shown in Figure 1, the multiple detection regions R are arranged side by side in a first direction X and a second direction Y. 【0013】 The pressure sensor 1 further includes a connection part 4, a gate line drive circuit 5, a signal line selection circuit 6, and a common wiring 7. The pressure sensor 1 also includes a gate line 8 and a signal line 9 (not shown). The connection part 4, the gate line drive circuit 5, the signal line selection circuit 6, the common wiring 7, the gate line 8, and the signal line 9 are provided between the substrate 10 and the protective layer 90. In a plan view, each of the connection part 4, the gate line drive circuit 5, the signal line selection circuit 6, and the common wiring 7 is superimposed on the non-detection part 3. 【0014】 The connection section 4 is for connecting the pressure sensor 1 to a drive IC (Integrated Circuit) (not shown) located outside the pressure sensor 1. The drive IC may be mounted as a COF (Chip On Film) on a flexible printed circuit board or rigid circuit board connected to the connection section 4. Alternatively, the drive IC may be mounted as a COG (Chip On Glass) in the area of ​​the circuit board 10 that overlaps with the non-detection section 3. 【0015】 The gate line drive circuit 5 is a circuit that drives multiple gate lines 8 based on various control signals from the drive IC. The gate line drive circuit 5 sequentially or simultaneously selects multiple gate lines 8 and supplies gate drive signals to the selected gate lines 8. 【0016】 The signal line selection circuit 6 is a switch circuit that sequentially or simultaneously selects a plurality of signal lines 9. The signal line selection circuit 6 is, for example, a multiplexer. The signal line selection circuit 6 connects the selected signal line 9 and the driving IC based on a selection signal supplied from the driving IC. 【0017】 The common wiring 7 is a wiring for supplying a predetermined voltage to the common electrode, and is arranged along the outer edge 3a of the non-detection portion 3. The common wiring 7 is connected to the driving IC via the connection portion 4, and a constant voltage is supplied from the driving IC. 【0018】 FIG. 2 is a plan view showing a configuration example of the pressure sensor 1 shown in FIG. 1. Here, the detection portion 2 of the pressure sensor 1 will be described. In FIG. 2, the protective layer 90 is omitted. 【0019】 The pressure sensor 1 includes a plurality of detection regions R and a partition wall 80. In the example shown in FIG. 2, the plurality of detection regions R are arranged side by side in the first direction X and the second direction Y. 【0020】 Each of the plurality of detection regions R includes a detection electrode 50, a common electrode 60, a pressure-sensitive layer 70, and a transistor 30 (not shown). The detection electrode 50 includes one electrode 50a extending in the second direction Y and a plurality of electrodes 50b extending from the electrode 50a in the first direction X. The common electrode 60 includes one electrode 60a extending in the second direction Y and a plurality of electrodes 60b extending from the electrode 60a in the first direction X. The electrodes 50b and the electrodes 60b are alternately arranged in the second direction Y. The pressure-sensitive layer 70 overlaps the detection electrode 50 and the common electrode 60. The pressure-sensitive layer 70 has, for example, a rectangular shape. 【0021】 The partition wall 80 is positioned between two adjacent pressure-sensitive layers 70 in a first direction X or a second direction Y. In the example shown in Figure 2, the partition wall 80 comprises a plurality of first partition walls 80a arranged side by side in the first direction X and extending in the second direction Y, and a plurality of second partition walls 80b arranged side by side in the second direction Y and extending in the first direction X. Two first partition walls 80a are positioned between adjacent pressure-sensitive layers 70 in the first direction X. Two second partition walls 80b are positioned between adjacent pressure-sensitive layers 70 in the second direction Y. The intersecting first partition walls 80a and second partition walls 80b are connected to each other. As a result, the partition wall 80 as a whole is formed in a grid shape that surrounds each of the plurality of pressure-sensitive layers 70. 【0022】 In the example shown in Figure 2, the partition wall 80 has a plurality of openings AP1 that overlap with the pressure-sensitive layer 70. The partition wall 80 also has a plurality of openings AP2 that do not overlap with the pressure-sensitive layer 70. In the example shown in Figure 2, the openings AP1 have a rectangular shape that is the same size as the pressure-sensitive layer 70. The partition wall 80 has rows in which the openings AP1 and AP2 are arranged alternately in the first direction X, and rows in which a plurality of openings AP2 are repeatedly arranged in the first direction X. These rows are arranged alternately in the second direction Y. The partition wall 80 also has rows in which the openings AP1 and AP2 are arranged alternately in the second direction Y, and rows in which a plurality of openings AP2 are repeatedly arranged in the second direction Y. These rows are arranged alternately in the first direction X. 【0023】 Figure 3 is a schematic cross-sectional view of the pressure sensor 1 along the line III-III in Figure 2. The pressure sensor 1 comprises a substrate 10, an insulating layer 20, a plurality of transistors 30, an insulating layer 40, a plurality of detection electrodes 50, a plurality of common electrodes 60, a plurality of pressure-sensitive layers 70, a partition wall 80, and a protective layer 90. The pressure sensor 1 further comprises a connection part 4 shown in Figure 1, a gate line drive circuit 5, a signal line selection circuit 6, and common wiring 7. The pressure sensor 1 further comprises a gate line 8 (not shown) and a signal line 9. 【0024】 The substrate 10 comprises a main surface (bottom surface) 10A and a main surface (top surface) 10B opposite to the main surface 10A. The main surfaces 10A and 10B are planes substantially parallel to the XY plane. The insulating layer 20 covers the main surface 10B. Each of the plurality of transistors 30 is positioned on the insulating layer 20 for each detection region R. 【0025】 The transistor 30 comprises a semiconductor layer 30a, a gate insulating film 30b, a gate electrode 30c, a drain electrode 30d, and a source electrode 30e. The semiconductor layer 30a is located on the insulating layer 20. The gate insulating film 30b is located on the semiconductor layer 30a. The gate electrode 30c is located on the gate insulating film 30b. The drain electrode 30d is located on the semiconductor layer 30a. The drain electrode 30d is electrically connected to a gate line 8 (not shown). The source electrode 30e is located on the semiconductor layer 30a. The source electrode 30e is electrically connected to a signal line 9 (not shown). 【0026】 The insulating layer 40 covers the insulating layer 20 and each of the multiple transistors 30. The insulating layer 40 has a surface 40B facing the protective layer 90. Surface 40B is flattened. Although not shown, the connection part 4, gate line drive circuit 5, signal line selection circuit 6, common wiring 7, gate line 8 and signal line 9 are provided between the main surface 10B and surface 40B. 【0027】 Each of the multiple detection electrodes 50 is positioned on the surface 40B for each detection region R. The detection electrodes 50 are electrically connected to the drain electrode 30d and electrically connected to the transistor 30. Each of the multiple common electrodes 60 is positioned on the surface 40B for each detection region R. In the detection region R, the detection electrodes 50 and the common electrodes 60 are adjacent to each other via the pressure-sensitive layer 70. The detection electrodes 50 and the common electrodes 60 are positioned on the same plane. In other words, the pressure sensor 1 is equipped with so-called parallel electrodes. 【0028】 Each of the multiple pressure-sensitive layers 70 is formed for each detection area R. The pressure-sensitive layer 70 covers the detection electrode 50 and the common electrode 60. The pressure-sensitive layer 70 is in contact with surface 40B between the detection electrode 50 and the common electrode 60. The pressure-sensitive layer 70 is in contact with surface 40B between the detection electrode 50 and the partition wall 80, and between the common electrode 60 and the partition wall 80. 【0029】 The partition wall 80 is positioned on surface 40B. In the example shown in Figure 3, two first partition walls 80a are positioned on surface 40B between two adjacent pressure-sensitive layers 70. Each of the first partition walls 80a has a side surface 81S facing the pressure-sensitive layer 70 and a side surface 82S opposite to side surface 81S. Side surface 81S is in contact with the pressure-sensitive layer 70. Side surface 81S faces side surface 81S of the other first partition wall 80a via the pressure-sensitive layer 70. An opening AP1 is formed between the opposing side surfaces 81S. The detection electrode 50, common electrode 60, and pressure-sensitive layer 70 are positioned in the opening AP1. 【0030】 Side surface 82S faces another side surface 82S of the first partition wall 80a through a gap S. An opening AP2 is formed between the opposing side surfaces 82S. Surface 40B is exposed in the opening AP2. 【0031】 The protective layer 90 covers each of the multiple pressure-sensitive layers 70. In the example shown in Figure 3, the protective layer 90 covers each of the multiple pressure-sensitive layers 70 and the partition wall 80, covering the entire surface of the pressure sensor 1. The protective layer 90 has an input surface 1a on the side opposite to the side facing the substrate 10. 【0032】 The substrate 10 is a resin layer formed of a resin such as polyimide (PI). The insulating layers 20 and 40 are inorganic or organic insulating films. The insulating layer 20 is formed of a polyimide-based resin, for example. The partition wall 80 is formed of an insulating material such as an acrylic-based resin or an epoxy-based resin, for example. The protective layer 90 is a substrate that has insulating and flexible properties. The protective layer 90 is a substrate or film formed of a resin such as polycarbonate (PC) or polyethylene terephthalate (PET), an inorganic film formed of an inorganic material such as SiO or SiN, or a decorative film. 【0033】 The detection electrode 50 and the common electrode 60 are electrodes formed from metallic materials such as molybdenum tungsten alloy (MoW), aluminum titanium alloy (AlTi), and copper, silver nanoink, or conductive polymers such as PEDOT / PSS (Poly(3,4-ethylenedioxythiophene) / poly(styrenesulfonate)). 【0034】 The pressure-sensitive layer 70 is not particularly limited as long as it is made of a material whose resistance changes with pressure, and for example, it is made of a material that includes a conductive material. The pressure-sensitive layer 70 is made of, for example, carbon paste or silver nano-ink. The pressure-sensitive layer 70 may further include a spacer material to increase the change in resistance with respect to pressure changes. The pressure sensor 1 may include two or more pressure-sensitive layers as the pressure-sensitive layer 70, each having a different change in resistance with respect to pressure changes. Alternatively, the pressure-sensitive layer 70 may be composed of two or more pressure-sensitive layers that have different changes in resistance with respect to pressure changes. 【0035】 A pressure-sensitive layer 70 formed from a material containing such conductive materials has a high resistance value when no pressure is applied because the contact area between the conductive materials is small. When pressure is applied to the detection unit 2, the pressure-sensitive layer 70 deforms, increasing the contact area between the conductive materials contained in the pressure-sensitive layer 70, thus decreasing the resistance value of the pressure-sensitive layer 70. When further pressure is applied to the detection unit 2 and the amount of deformation of the pressure-sensitive layer 70 increases, the contact area between the conductive materials increases further, and the resistance value of the pressure-sensitive layer 70 decreases even further. In this way, the resistance value of a pressure-sensitive layer 70 formed from a material containing conductive materials changes in response to changes in pressure. 【0036】 Figure 4 is a circuit diagram showing an example of the circuit configuration of the pressure sensor 1 shown in Figure 1. As shown in Figure 4, the gate electrode 30c is electrically connected to the gate line 8. The source electrode 30e is electrically connected to the signal line 9. In other words, each of the transistors 30 is electrically connected to the gate line 8 and the signal line 9. 【0037】 The gate line 8 extends in the first direction X and is electrically connected to each of the transistors 30 in the multiple detection regions R aligned in the first direction X. The signal line 9 extends in the second direction Y, intersects with the gate line 8, and is electrically connected to each of the transistors 30 in the multiple detection regions R aligned in the second direction Y. The detection electrode 50 is electrically connected to the drain electrode 30d. 【0038】 When the gate line 8 is scanned, the detection electrode 50 and the signal line 9 are electrically connected. This allows the value of the current flowing between the detection electrode 50 and the common electrode 60 to be obtained via the signal line 9. From the obtained current value, the pressure applied to the input surface 1a can be detected. 【0039】 Figure 5 is a cross-sectional view illustrating the state in which the input surface 1a of the pressure sensor 1 is pressed. Transistor 30 is omitted in Figure 5. 【0040】 In the detection region R, the detection electrode 50 and the common electrode 60 are adjacent to each other via a pressure-sensitive layer 70. When the input surface 1a of the pressure sensor 1 is not pressed, the pressure-sensitive layer 70 has a high resistance value. Therefore, when the input surface 1a is not pressed, the detection electrode 50 and the common electrode 60 are not electrically connected. 【0041】 As shown in Figure 5, when the input surface 1a is pressed, for example by a finger, pressure is applied to the input surface 1a in the direction from the protective layer 90 toward the substrate 10, i.e., in the A1 direction. At this time, in the detection region R, the pressure-sensitive layer 70 is compressed in the A1 direction, increasing the area in which the conductive materials contained in the pressure-sensitive layer 70 are in contact with each other, and decreasing the resistance value of the pressure-sensitive layer 70. As a result, current flows between the detection electrode 50 and the common electrode 60 via the pressure-sensitive layer 70. 【0042】 As the pressure applied to the input surface 1a in the A1 direction increases, the pressure-sensitive layer 70 is further compressed in the A1 direction, and the area in contact between the conductive materials increases further. As a result, the resistance of the pressure-sensitive layer 70 decreases further, and the current flowing between the detection electrode 50 and the common electrode 60 via the pressure-sensitive layer 70 increases. In other words, as the pressure applied to the input surface 1a increases, the value of the current flowing between the detection electrode 50 and the common electrode 60 via the pressure-sensitive layer 70 (current value) increases. By detecting such changes in current value, changes in the pressure applied to the input surface 1a can be detected. 【0043】 Next, a method for manufacturing the pressure sensor 1 according to the first embodiment will be described. Figures 6 to 8 are diagrams illustrating an example of a method for manufacturing the pressure sensor 1. Figures 6 to 8 show a cross-section of a part of the detection unit 2 of the pressure sensor 1. 【0044】 In the manufacturing of the pressure sensor 1, first, a substrate 10 is formed on a support substrate 11, and an insulating layer 20 is formed on the substrate 10 (step S1 in Figure 6). The support substrate 11 is made of, for example, glass. After step S1, a transistor 30 is formed on the insulating layer 20, and an insulating layer 40 covering the transistor 30 is formed (step S2 in Figure 6). After step S2, a detection electrode 50 and a common electrode 60 are formed on the insulating layer 40 (step S3 in Figure 6). The detection electrode 50 and the common electrode 60 are formed, for example, by patterning a metal film formed on the insulating layer 40 by sputtering or the like. The detection electrode 50 and the common electrode 60 may also be formed, for example, by coating silver nano-ink or a conductive polymer onto the insulating layer 40 by printing or the like. 【0045】 After step S3, an insulating layer 81, which will serve as the base for the partition wall 80, is formed on the insulating layer 40 (step S4 in Figure 7). The insulating layer 81 is made of an insulating material such as an acrylic resin or an epoxy resin. The insulating layer 81 covers the detection electrode 50 and the common electrode 60. After step S4, an opening AP1 is formed in the insulating layer 81, and the partition wall 80 is formed (step S5 in Figure 7). The partition wall 80 is formed, for example, by patterning the insulating layer 81 using photolithography. Alternatively, the partition wall 80 may be formed by coating the partition wall material onto the insulating layer 40 using printing methods such as screen printing, flexographic printing, and inkjet printing. 【0046】 After step S5, a pressure-sensitive layer 70 is formed in the opening AP1 (step S6 in Figure 7). The pressure-sensitive layer 70 is formed by applying a pressure-sensitive layer material onto the detection electrode 50 by a printing method such as screen printing, flexographic printing, and inkjet printing. The pressure-sensitive layer material is a material containing a conductive material, such as silver nano-ink or carbon paste. The pressure-sensitive layer material is applied, for example, within a region surrounded by a partition wall 80 in a plan view, and the pressure-sensitive layer 70 is formed within that region. This prevents the pressure-sensitive layer material from being applied to undesirable locations and prevents the pressure-sensitive layer material from spreading before curing. 【0047】 After step S6, a protective layer 90 is formed on the pressure-sensitive layer 70 and the partition wall 80, and the pressure sensor 1 is manufactured (step S7 in Figure 8). The protective layer 90 may be formed, for example, by attaching a film-like protective layer 90 to the pressure-sensitive layer 70 and the partition wall 80. Alternatively, the protective layer 90 may be formed by CVD or printing. After step S7, the support substrate 11 may be peeled off and removed from the substrate 10 by laser lift-off processing or the like (step S8 in Figure 8). 【0048】 In the manufacturing of pressure sensors, a pressure-sensitive layer is sometimes formed by placing a sheet-like pressure-sensitive layer on top of the detection electrode. However, if the pressure-sensitive layer is misaligned from the desired location, the reliability of the pressure sensor may decrease. Furthermore, the method of fixing the pressure-sensitive layer onto the detection electrode may also present problems. 【0049】 In this embodiment, the pressure-sensitive layer is formed by applying the pressure-sensitive layer material onto the detection electrode using a printing method. Therefore, it is possible to prevent the pressure-sensitive layer from being positioned in a misaligned location, and there is no need to fix the pressure-sensitive layer onto the detection electrode by other means. 【0050】 Therefore, according to this embodiment, it is possible to provide a method for manufacturing a pressure sensor that can suppress a decrease in reliability. 【0051】 (Second Embodiment) Figure 9 is a plan view showing an example configuration of the pressure sensor 1 according to the second embodiment. A description of the configuration similar to that of the first embodiment described above will be omitted by referring to the above description. Here, the detection unit 2 of the pressure sensor 1 will be described. In Figure 9, the protective layer 90 is omitted. 【0052】 The pressure sensor 1 comprises multiple detection regions R, a partition wall 80, and a common electrode 60 (not shown). In the example shown in Figure 6, the multiple detection regions R are arranged side by side in a first direction X and a second direction Y. 【0053】 Each of the multiple detection regions R comprises a detection electrode 50, a pressure-sensitive layer 70, and a transistor 30 (not shown). The pressure-sensitive layer 70 is superimposed on the detection electrode 50. In the example shown in Figure 9, the pressure-sensitive layer 70 has a rectangular shape with the same size as the detection electrode 50, but it is not limited to this, and the pressure-sensitive layer 70 may have a smaller area than the detection electrode 50. 【0054】 In the example shown in Figure 9, the partition wall 80 comprises a plurality of first partition walls 80a arranged in a first direction X and extending in a second direction Y, and a plurality of second partition walls 80b arranged in a second direction Y and extending in the first direction X. Two first partition walls 80a are arranged between adjacent pressure-sensitive layers 70 in the first direction X. Two second partition walls 80b are arranged between adjacent pressure-sensitive layers 70 in the second direction Y. The intersecting first partition walls 80a and second partition walls 80b are connected to each other. As a result, the partition wall 80 as a whole is formed in a grid shape that surrounds each of the plurality of pressure-sensitive layers 70. The partition wall 80 has a plurality of openings AP1 that overlap with the pressure-sensitive layers 70. The partition wall 80 also has a plurality of openings AP2 that do not overlap with the pressure-sensitive layers 70. In the example shown in Figure 9, the openings AP1 have a rectangular shape that is the same size as the pressure-sensitive layers 70. 【0055】 Figure 10 is a schematic cross-sectional view of the pressure sensor 1 along line XX in Figure 9. A description of a configuration similar to that of the first embodiment described above will be omitted by referring to the description above. 【0056】 The pressure sensor 1 comprises a substrate 10, an insulating layer 20, a plurality of transistors 30, an insulating layer 40, a plurality of detection electrodes 50, a common electrode 60, a plurality of pressure-sensitive layers 70, a partition wall 80, and a protective layer 90. 【0057】 Each of the multiple detection electrodes 50 is positioned on the surface 40B for each detection region R. Each of the multiple pressure-sensitive layers 70 is formed for each detection region R. The pressure-sensitive layers 70 are positioned on the detection electrodes 50. In the example shown in Figure 10, the pressure-sensitive layers 70 cover the detection electrodes 50. 【0058】 The partition wall 80 is positioned on surface 40B. In the example shown in Figure 10, two first partition walls 80a are positioned on surface 40B between two adjacent pressure-sensitive layers 70. Each of the first partition walls 80a has a side surface 81S facing the pressure-sensitive layer 70 and a side surface 82S opposite to side surface 81S. Side surface 81S faces side surface 81S of the other first partition wall 80a via the pressure-sensitive layer 70. An opening AP1 is formed between the opposing side surfaces 81S. The detection electrode 50 and the pressure-sensitive layer 70 are positioned in the opening AP1. 【0059】 The common electrode 60 covers each of the multiple pressure-sensitive layers 70. In the example shown in Figure 10, the common electrode 60 covers each of the multiple pressure-sensitive layers 70 and the partition wall 80, covering the entire surface of the pressure sensor 1. The common electrode 60 faces each of the multiple detection electrodes 50 in the third direction Z via the pressure-sensitive layer 70. 【0060】 The protective layer 90 covers the common electrode 60. The protective layer 90 has an input surface 1a on the side opposite to the side facing the substrate 10. The common electrode 60 is, for example, a metal film deposited on the side of the protective layer 90 opposite to the input surface 1a. Note that the pressure sensor 1 does not necessarily have a protective layer 90; in this case, the side of the common electrode 60 opposite to the side facing the substrate 10 becomes the input surface 1a. 【0061】 Thus, in the pressure sensor 1 according to the second embodiment, each of the multiple detection electrodes 50 and the common electrode 60 are arranged to face each other. In other words, the pressure sensor 1 according to the second embodiment is equipped with so-called opposing electrodes. 【0062】 Next, a method for manufacturing the pressure sensor 1 according to the second embodiment will be described. A description of the configuration similar to that of the method for manufacturing the pressure sensor 1 according to the first embodiment described above will be omitted by referring to the above description. Figures 11 to 13 are diagrams illustrating an example of a method for manufacturing the pressure sensor 1. Figures 11 to 13 show a cross-section of a part of the detection unit 2 of the pressure sensor 1. 【0063】 In the manufacturing of the pressure sensor 1, first, a substrate 10 is formed on a support substrate 11, and an insulating layer 20 is formed on the substrate 10 (step S1 in Figure 11). After step S1, a transistor 30 is formed on the insulating layer 20, and an insulating layer 40 covering the transistor 30 is formed (step S2 in Figure 11). After step S2, a detection electrode 50 is formed on the insulating layer 40 (step S3 in Figure 11). The detection electrode 50 is formed, for example, by patterning a metal film formed on the insulating layer 40 by sputtering. The detection electrode 50 may also be formed, for example, by applying silver nano-ink or a conductive polymer onto the insulating layer 40 by printing or other methods. 【0064】 After step S3, an insulating layer 81, which will serve as the base for the partition wall 80, is formed on top of the insulating layer 40 (step S4 in Figure 12). The insulating layer 81 covers the detection electrode 50. After step S4, an opening AP1 is formed in the insulating layer 81, and the partition wall 80 is formed (step S5 in Figure 12). 【0065】 After step S5, a pressure-sensitive layer 70 is formed in the opening AP1 (step S6 in Figure 12). The pressure-sensitive layer 70 is formed by applying a pressure-sensitive layer material onto the detection electrode 50 by a printing method such as screen printing, flexographic printing, and inkjet printing. The pressure-sensitive layer material is a material containing a conductive material, such as silver nano-ink or carbon paste. The pressure-sensitive layer material is applied, for example, within a region surrounded by a partition wall 80 in a plan view, and the pressure-sensitive layer 70 is formed within that region. This prevents the pressure-sensitive layer material from being applied to undesirable locations and prevents the pressure-sensitive layer material from spreading before curing. 【0066】 After step S6, a common electrode 60 is formed on the pressure-sensitive layer 70 and the partition wall 80 (step S7 in Figure 13). The common electrode 60 is formed, for example, by sputtering. The common electrode 60 may also be formed by coating the pressure-sensitive layer 70 and the partition wall 80 with silver nano-ink or a conductive polymer using a printing method or the like. 【0067】 After step S7, a protective layer 90 is formed on the common electrode 60, and the pressure sensor 1 is manufactured (step S8 in Figure 13). The protective layer 90 may be formed, for example, by attaching a film-like protective layer 90 to the common electrode 60. Alternatively, the protective layer 90 may be formed by CVD or printing. Alternatively, the protective layer 90 and the common electrode 60 may be formed simultaneously by forming a metal film on one side of the film-like protective layer 90 and attaching the side of the protective layer 90 on which the common electrode 60 is formed to the pressure-sensitive layer 70. After step S8, the support substrate 11 may be peeled off and removed from the substrate 10 by laser lift-off processing or the like (step S9 in Figure 13). The same effects as in the first embodiment can be obtained in the manufacturing method of the pressure sensor 1 according to this second embodiment. 【0068】 As described above, this embodiment provides a method for manufacturing a pressure sensor that can suppress a decrease in reliability. 【0069】 Furthermore, this invention is not limited to the embodiments described above, and its components can be modified and implemented without departing from the spirit of the invention. Various inventions can also be formed by appropriate combinations of the multiple components disclosed in each embodiment. For example, some components may be removed from all the components shown in each embodiment. Moreover, components from different embodiments may be combined as appropriate. [Explanation of symbols] 【0070】 1...Pressure sensor 2...Detection unit 3...Non-detection unit 4…Connection section 5…Gate line drive circuit 6…Signal line selection circuit 7…Common wiring 8...Gate line 9...Signal line 10...Substrate 20...Insulating layer 30...Transistor 40...Insulating layer 50...Detection electrode 60... Common electrode 70... Pressure-sensitive layer 80... Separation wall 90... Protective layer R...Detection area

Claims

[Claim 1] A transistor is formed above the support substrate. An insulating layer is formed to cover the transistor, A detection electrode connected to the transistor and a common electrode are formed on the insulating layer. A method for manufacturing a pressure sensor, comprising forming a pressure-sensitive layer on the detection electrode by applying a pressure-sensitive layer material by printing. [Claim 2] A transistor is formed above the support substrate. An insulating layer is formed to cover the transistor, A detection electrode connected to the transistor is formed on the insulating layer. A pressure-sensitive layer is formed on the aforementioned detection electrode by applying a pressure-sensitive layer material by a printing method. A method for manufacturing a pressure sensor, comprising forming a common electrode on the pressure-sensitive layer. [Claim 3] The method for manufacturing a pressure sensor according to claim 1 or 2, wherein the printing method is inkjet printing, screen printing, or flexographic printing. [Claim 4] The method for manufacturing a pressure sensor according to claim 1 or 2, wherein the pressure-sensitive layer material is a material containing a conductive material. [Claim 5] The method for manufacturing a pressure sensor according to claim 4, wherein the pressure-sensitive layer material is a material whose resistance value changes with changes in pressure. [Claim 6] Before forming the pressure-sensitive layer, a partition wall is formed on the insulating layer. The method for manufacturing a pressure sensor according to claim 1 or 2, wherein the pressure-sensitive layer is formed within the region surrounded by the partition wall. [Claim 7] The method for manufacturing a pressure sensor according to claim 6, wherein the partition wall is formed of an insulating material. [Claim 8] The method for manufacturing a pressure sensor according to claim 7, wherein the partition wall is formed of an acrylic resin or an epoxy resin. [Claim 9] A method for manufacturing a pressure sensor according to claim 1 or 2, wherein after forming the pressure-sensitive layer, the support substrate is peeled off.

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