Method of manufacturing a pressure sensor

Abstract

The present application relates to a method of manufacturing a pressure sensor. According to one embodiment, in the method of manufacturing a pressure sensor, a transistor is formed above a support substrate, an insulating layer covering the transistor is formed, a common electrode and a detection electrode connected to the transistor are formed on the insulating layer, and a pressure-sensitive layer is formed on the detection electrode by applying a pressure-sensitive layer material using a printing method.

Description

[0001] Cross-referencing of related applications This application claims priority based on Japanese Patent Application No. 2024-209875, filed on December 3, 2024, and invokes all the contents described in that Japanese Patent Application. Technical Field

[0002] Embodiments of the present invention relate to a method for manufacturing a pressure sensor. Background Technology

[0003] Various pressure sensors capable of detecting pressure distribution have been proposed. In such pressure sensors, manufacturing methods that can suppress reliability degradation are desirable. Summary of the Invention

[0004] According to one embodiment, in a method for manufacturing a pressure sensor, a transistor is formed above a support substrate, an insulating layer is formed covering the transistor, a common electrode and a detection electrode connected to the transistor are formed on the insulating layer, and a pressure-sensitive layer is formed on the detection electrode by applying a pressure-sensitive layer material using a printing method.

[0005] According to one embodiment, in a method for manufacturing a pressure sensor, a transistor is formed above a support substrate, an insulating layer is formed covering the transistor, a detection electrode connected to the transistor is formed on the insulating layer, a pressure-sensitive layer is formed on the detection electrode by applying a pressure-sensitive layer material using a printing method, and a common electrode is formed on the pressure-sensitive layer.

[0006] According to the embodiments, a method for manufacturing a pressure sensor that can suppress the reduction in reliability can be provided. Attached Figure Description

[0007] Figure 1 This is a top view showing an example configuration of the pressure sensor according to the first embodiment.

[0008] Figure 2 It is shown Figure 1 A top view of one embodiment of the pressure sensor shown.

[0009] Figure 3 It is along Figure 2 A schematic cross-sectional view of the pressure sensor along line III-III.

[0010] Figure 4 It is shown Figure 1 The circuit diagram shown is an example of the circuit configuration of a pressure sensor.

[0011] Figure 5 It is used for explanation Figure 1 The image shows a cross-sectional view of the pressure sensor's input surface being pressed.

[0012] Figure 6 It is used for explanation Figure 2 A diagram illustrating an example of a method for manufacturing a pressure sensor.

[0013] Figure 7 It is used for explanation Figure 2 A diagram illustrating an example of a method for manufacturing a pressure sensor.

[0014] Figure 8 It is used for explanation Figure 2 A diagram illustrating an example of a method for manufacturing a pressure sensor.

[0015] Figure 9 This is a top view showing an example of the configuration of the pressure sensor according to the second embodiment.

[0016] Figure 10 It is along Figure 9 A schematic cross-sectional view of the pressure sensor for the XX line.

[0017] Figure 11 It is used for explanation Figure 9 A diagram illustrating an example of a method for manufacturing a pressure sensor.

[0018] Figure 12 It is used for explanation Figure 9 A diagram illustrating an example of a method for manufacturing a pressure sensor.

[0019] Figure 13 It is used for explanation Figure 9 A diagram illustrating an example of a method for manufacturing a pressure sensor. Detailed Implementation

[0020] Hereinafter, this embodiment will be described with reference to the accompanying drawings. It should be noted that the disclosed content is merely an example, and appropriate modifications that can be readily conceived by those skilled in the art while maintaining the spirit of the invention are of course included within the scope of this invention. Furthermore, regarding the accompanying drawings, to make the description clearer, the width, thickness, shape, etc., of each part are sometimes schematically shown compared to the actual form; however, this is merely an example and does not limit the interpretation of the invention. Additionally, in this specification and the various figures, the same reference numerals are used to denote constituent elements that perform the same or similar functions as those described with respect to previously presented figures, and sometimes repeated detailed descriptions are appropriately omitted.

[0021] Figure 1This is a top view showing an example configuration of the pressure sensor 1 according to this embodiment. In one example, the first direction X, the second direction Y, and the third direction Z are orthogonal to each other, but they may also intersect at an angle 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 called the "upper side" (or simply "up"), and the direction from the protective layer 90 toward the substrate 10 is called the "lower side" (or simply "lower"). When referred to as "the second member above the first member" and "the second member below the first member", the second member may be connected to the first member or may be separated from the first member. In addition, there is an observation position for observing the pressure sensor 1 at the front end of the arrow indicating the third direction Z, and the observation from this observation position toward the XY plane defined by the first direction X and the second direction Y is called top view.

[0022] 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 as a flat plate parallel to the XY plane. When viewed from above, the substrate 10 has, for example, a rectangular shape.

[0023] exist Figure 1 In the example shown, the pressure sensor 1 has a protective layer 90. The protective layer 90 is formed as a flat plate parallel to the XY plane. The substrate 10 and the protective layer 90 overlap when viewed from above.

[0024] The pressure sensor 1 has an input surface 1a on one side for applying pressure. Figure 1 In the example shown, the pressure sensor 1 has an input surface 1a on the side of the protective layer 90 opposite to the surface opposite to the substrate 10. The pressure sensor 1 detects the pressure applied to the input surface 1a.

[0025] The input surface 1a, viewed from above, includes a detection section 2 for detecting pressure and a frame-shaped non-detection section 3 surrounding the detection section 2. The detection section 2 has multiple detection areas R. Figure 1 In the example shown, multiple detection regions R are arranged in the first direction X and the second direction Y.

[0026] The pressure sensor 1 also includes a connection portion 4, a gate line driving circuit 5, a signal line selection circuit 6, and a common wiring 7. Additionally, the pressure sensor 1 includes a gate line 8 and a signal line 9 (not shown). The connection portion 4, gate line driving circuit 5, signal line selection circuit 6, common wiring 7, gate line 8, and signal line 9 are disposed between the substrate 10 and the protective layer 90. Each of the connection portion 4, gate line driving circuit 5, signal line selection circuit 6, and common wiring 7 overlaps with the non-detection portion 3 when viewed from above.

[0027] The connecting portion 4 is used to connect the pressure sensor 1 to a driver IC (integrated circuit) (not shown) disposed outside the pressure sensor 1. It should be noted that the driver IC can also be mounted as a COF (Chip On Film) on a flexible printed circuit board or a rigid substrate connected to the connecting portion 4. Alternatively, the driver IC can also be mounted as a COG (Chip On Glass) in the area of ​​the substrate 10 overlapping with the non-detection portion 3.

[0028] The gate line drive circuit 5 is a circuit that drives multiple gate lines 8 based on various control signals from the driver IC. The gate line drive circuit 5 selects multiple gate lines 8 sequentially or simultaneously and supplies gate drive signals to the selected gate lines 8.

[0029] The signal line selection circuit 6 is a switching circuit that selects multiple signal lines 9 sequentially or simultaneously. The signal line selection circuit 6 is, for example, a multiplexer. Based on a selection signal supplied from the driver IC, the signal line selection circuit 6 connects the selected signal line 9 to the driver IC.

[0030] The common wiring 7 is a wiring used to supply a specified voltage to the common electrode, and is arranged along the outer edge 3a of the non-detection section 3. The common wiring 7 is connected to the driver IC via the connection section 4 and is supplied with a certain voltage from the driver IC.

[0031] Figure 2 It is shown Figure 1 This is a top view of one configuration example of the pressure sensor 1 shown. Here, the detection unit 2 of the pressure sensor 1 will be described. Figure 2 In the text, the protective layer 90 is omitted.

[0032] Pressure sensor 1 has multiple detection areas R and partitions 80. Figure 2 In the example shown, multiple detection regions R are arranged in the first direction X and the second direction Y.

[0033] Each of the multiple 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 an electrode 50a extending along a second direction Y and multiple electrodes 50b extending from the electrode 50a along a first direction X. The common electrode 60 includes an electrode 60a extending along the second direction Y and multiple electrodes 60b extending from the electrode 60a along the first direction X. Electrodes 50b and 60b are alternately arranged in the second direction Y. The pressure-sensitive layer 70 overlaps with the detection electrode 50 and the common electrode 60. The pressure-sensitive layer 70 has, for example, a rectangular shape.

[0034] The partition 80 is disposed between two adjacent pressure-sensitive layers 70 in the first direction X or the second direction Y. Figure 2 In the example shown, the partition 80 includes a plurality of first partitions 80a arranged in the first direction X and extending along the second direction Y, and a plurality of second partitions 80b arranged in the second direction Y and extending along the first direction X. Two first partitions 80a are disposed between adjacent pressure-sensitive layers 70 in the first direction X. Two second partitions 80b are disposed between adjacent pressure-sensitive layers 70 in the second direction Y. The intersecting first partitions 80a and second partitions 80b are connected to each other. Thus, the partition 80 is formed as a whole into a lattice shape surrounding the plurality of pressure-sensitive layers 70.

[0035] exist Figure 2 In the example shown, the partition wall 80 has multiple openings AP1 that overlap with the pressure-sensitive layer 70. Additionally, the partition wall 80 also has multiple openings AP2 that do not overlap with the pressure-sensitive layer 70. Figure 2 In the example shown, the opening AP1 has a rectangular shape with the same size as the pressure-sensitive layer 70. A column of openings AP1 and AP2 alternately arranged in the first direction X, and a column of multiple openings AP2 repeatedly arranged in the first direction X, are formed in the partition wall 80. These columns are arranged alternately in the second direction Y. Additionally, a column of openings AP1 and AP2 alternately arranged in the second direction Y, and a column of multiple openings AP2 repeatedly arranged in the second direction Y, are formed in the partition wall 80. These columns are arranged alternately in the first direction X.

[0036] Figure 3 It is along Figure 2 A schematic cross-sectional view of pressure sensor 1 along line III-III.

[0037] The pressure sensor 1 comprises a substrate 10, an insulating layer 20, multiple transistors 30, an insulating layer 40, multiple detection electrodes 50, multiple common electrodes 60, multiple pressure-sensitive layers 70, a partition wall 80, and a protective layer 90. The pressure sensor 1 also includes... Figure 1 The connection part 4, gate line drive circuit 5, signal line selection circuit 6, and common wiring 7 are shown. The pressure sensor 1 also includes a gate line 8 and a signal line 9 (not shown).

[0038] The substrate 10 has a main surface (lower surface) 10A and a main surface (upper surface) 10B opposite to the main surface 10A. The main surfaces 10A and 10B are surfaces that are substantially parallel to the XY plane. An insulating layer 20 covers the main surface 10B. A plurality of transistors 30 are respectively arranged on the insulating layer 20 according to their respective detection regions R.

[0039] Transistor 30 includes 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 disposed on the insulating layer 20. The gate insulating film 30b is disposed on the semiconductor layer 30a. The gate electrode 30c is disposed on the gate insulating film 30b. The drain electrode 30d is disposed on the semiconductor layer 30a. The drain electrode 30d is electrically connected to a gate line 8 (not shown). The source electrode 30e is disposed on the semiconductor layer 30a. The source electrode 30e is electrically connected to a signal line 9 (not shown).

[0040] An insulating layer 40 covers the insulating layer 20 and each of the plurality of transistors 30. The insulating layer 40 has a surface 40B opposite to the protective layer 90. Surface 40B is planarized. Although not shown, the connecting portion 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 disposed between the main surface 10B and the surface 40B.

[0041] Multiple detection electrodes 50 are each arranged on surface 40B according to their respective detection regions R. The detection electrodes 50 are electrically connected to the drain electrode 30d and, consequently, to the transistor 30. Multiple common electrodes 60 are each arranged on surface 40B according to their respective detection regions R. In the detection regions R, the detection electrodes 50 and common electrodes 60 are adjacent to each other via the pressure-sensitive layer 70. The detection electrodes 50 and common electrodes 60 are arranged on the same plane. That is, the pressure sensor 1 has so-called parallel electrodes.

[0042] Multiple pressure-sensitive layers 70 are each formed according to their respective detection regions 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 the surface 40B between the detection electrode 50 and the common electrode 60. The pressure-sensitive layer 70 is also in contact with the surface 40B between the detection electrode 50 and the partition wall 80, and between the common electrode 60 and the partition wall 80.

[0043] The adjacent 80 is positioned on surface 40B. Figure 3 In the example shown, two first partition walls 80a are disposed on surface 40B between two adjacent pressure-sensitive layers 70. Each of the first partition walls 80a has a side surface 81S opposite to the pressure-sensitive layer 70 and a side surface 82S opposite to the side surface 81S. The side surface 81S is in contact with the pressure-sensitive layer 70. The side surface 81S is opposite to the side surface 81S of the other first partition wall 80a through the pressure-sensitive layer 70. An opening AP1 is formed between the opposing side surfaces 81S. The detection electrode 50, the common electrode 60, and the pressure-sensitive layer 70 are disposed in the opening AP1.

[0044] Side 82S is positioned opposite to the side 82S of the other first partition wall 80a across a gap S. An opening AP2 is formed between the opposing side 82S. Surface 40B is exposed in the opening AP2.

[0045] The protective layer 90 covers each of the multiple pressure-sensitive layers 70. Figure 3 In the example shown, the protective layer 90 covers each of the plurality of pressure-sensitive layers 70 and the partitions 80, and covers the entire surface of the pressure sensor 1. The protective layer 90 has an input surface 1a on the side opposite to the surface opposite to the substrate 10.

[0046] The substrate 10 is, for example, a resin layer formed from a resin such as polyimide (PI). Insulating layers 20 and 40 are inorganic or organic insulating films. Insulating layer 20 is, for example, formed from a polyimide-based resin. The partition 80 is, for example, formed from an insulating material such as an acrylic resin or an epoxy resin. The protective layer 90 is a substrate possessing both insulation and flexibility. The protective layer 90 is, for example, a substrate or film formed from a resin such as polycarbonate (PC) or polyethylene terephthalate (PET), an inorganic film formed from inorganic materials such as SiO or SiN, or a decorative film.

[0047] The detection electrode 50 and the common electrode 60 are electrodes made of metal materials such as molybdenum-tungsten alloy (MoW), aluminum-titanium alloy (AlTi) and copper, silver nano-ink, or conductive polymers such as PEDOT / PSS (Poly(3,4-ethylenedioxythiophene) / poly(styrenesulfonate)).

[0048] The pressure-sensitive layer 70 can be made of a material whose resistance changes with pressure, and is not particularly limited; for example, it can be formed of a material containing a conductive material. The pressure-sensitive layer 70 may be formed of, for example, carbon paste, silver nano-ink, etc. The pressure-sensitive layer 70 may also include a spacer material to increase the change in resistance with respect to pressure changes. In the pressure sensor 1, the pressure-sensitive layer 70 may comprise two or more pressure-sensitive layers with different changes in resistance with respect to pressure changes. Furthermore, the pressure-sensitive layer 70 may also be composed of two or more pressure-sensitive layers with different changes in resistance with respect to pressure changes.

[0049] The pressure-sensitive layer 70, formed from a material containing conductive material, has a small contact area between the conductive materials when no pressure is applied, resulting in a high resistance value. When pressure is applied to the detection unit 2, the pressure-sensitive layer 70 deforms, increasing the contact area between the conductive materials and thus decreasing the resistance value. When further pressure is applied to the detection unit 2, increasing the deformation of the pressure-sensitive layer 70, the contact area between the conductive materials further increases, further decreasing the resistance value. Thus, the resistance value of the pressure-sensitive layer 70, formed from a material containing conductive material, changes according to the pressure.

[0050] Figure 4 It is shown Figure 1 The circuit diagram shown is an example of the circuit configuration of pressure sensor 1. (As shown...) Figure 4 As shown, the gate electrode 30c is electrically connected to the gate line 8. Additionally, the source electrode 30e is electrically connected to the signal line 9. That is, each of the transistors 30 is electrically connected to both the gate line 8 and the signal line 9.

[0051] Gate line 8 extends along a first direction X and is electrically connected to each of the transistors 30 of the plurality of detection regions R arranged in the first direction X. Signal line 9 extends along a second direction Y, intersects gate line 8, and is electrically connected to each of the transistors 30 of the plurality of detection regions R arranged in the second direction Y. Detection electrode 50 is electrically connected to drain electrode 30d.

[0052] When the gate line 8 is scanned, the detection electrode 50 is electrically connected to the signal line 9. Therefore, the value of the current flowing between the detection electrode 50 and the common electrode 60 can be obtained via the signal line 9. Based on the obtained current value, the pressure applied to the input surface 1a can be detected.

[0053] Figure 5 This is a cross-sectional view illustrating the pressed state of the input surface 1a of pressure sensor 1. Figure 5 Transistor 30 is omitted in the text.

[0054] In the detection area R, the detection electrode 50 and the common electrode 60 are adjacent to each other via the pressure-sensitive layer 70. When the input surface 1a of the pressure sensor 1 is not pressed, the pressure-sensitive layer 70 has a large resistance value. Therefore, when the input surface 1a is not pressed, the detection electrode 50 and the common electrode 60 are not electrically connected.

[0055] like Figure 5 As shown, when the input surface 1a is pressed, for example with a finger, pressure is applied to the input surface 1a in the direction from the protective layer 90 toward the substrate 10, i.e., the A1 direction. At this time, in the detection area R, the pressure-sensitive layer 70 is compressed in the A1 direction, the area of ​​the conductive materials contained in the pressure-sensitive layer 70 in contact with each other increases, and the resistance value of the pressure-sensitive layer 70 decreases. Therefore, current flows between the detection electrode 50 and the common electrode 60 through the pressure-sensitive layer 70.

[0056] When 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 of ​​the conductive materials in contact with each other further increases. As a result, the resistance of the pressure-sensitive layer 70 further decreases, and the current flowing through the pressure-sensitive layer 70 between the detection electrode 50 and the common electrode 60 increases. That is, as the pressure applied to the input surface 1a increases, the value of the current flowing through the pressure-sensitive layer 70 between the detection electrode 50 and the common electrode 60 (current value) increases. By detecting this change in current value, the change in pressure applied to the input surface 1a can be detected.

[0057] Next, the manufacturing method of the pressure sensor 1 according to the first embodiment will be described. Figures 6-8 This is a diagram illustrating an example of the manufacturing method of pressure sensor 1. Figures 6-8 A cross-section of a portion of the detection section 2 of the pressure sensor 1 is shown.

[0058] In the manufacture of pressure sensor 1, firstly, a substrate 10 is formed on a support substrate 11, and an insulating layer 20 is formed on the substrate 10. Figure 6 (Process S1). The support substrate 11 is formed, for example, from glass. After process S1, a transistor 30 is formed on the insulating layer 20, and an insulating layer 40 covering the transistor 30 is formed. Figure 6 Step S2). After step S2, a detection electrode 50 and a common electrode 60 are formed on the insulating layer 40. Figure 6 (Process S3). The detection electrode 50 and the common electrode 60 are formed, for example, by patterning a metal film formed on the insulating layer 40 using sputtering or the like. The detection electrode 50 and the common electrode 60 can also be formed, for example, by coating the insulating layer 40 with silver nano-ink or conductive polymer using a printing method.

[0059] After process S3, an insulating layer 81 is formed on the insulating layer 40 to form the basis of the partition wall 80. Figure 7 Step S4). The insulating layer 81 is formed of an insulating material such as acrylic resin or 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, forming a partition wall 80. Figure 7 (Process S5). The partition 80 is formed, for example, by patterning the insulating layer 81 using photolithography. Alternatively, the partition material can be coated onto the insulating layer 40 using printing methods such as screen printing, flexographic printing, and inkjet printing to form the partition 80.

[0060] After process S5, a pressure-sensitive layer 70 is formed at the opening AP1. Figure 7(Step S6). The pressure-sensitive layer 70 is formed by applying a pressure-sensitive layer material onto the detection electrode 50, for example, using printing methods 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, to the area surrounded by the partition wall 80 when viewed from above, thereby forming the pressure-sensitive layer 70 in that area. This prevents the pressure-sensitive layer material from being applied to undesirable areas and inhibits the expansion of the pressure-sensitive layer material before curing.

[0061] After process S6, a protective layer 90 is formed on the pressure-sensitive layer 70 and the partition 80, thereby manufacturing the pressure sensor 1. Figure 8 (Step S7). The protective layer 90 can be formed, for example, by adhering a film-like protective layer 90 onto the pressure-sensitive layer 70 and the spacer 80. Alternatively, the protective layer 90 can also be formed using CVD, printing, or the like. After step S7, the support substrate 11 can be peeled off and removed from the substrate 10 using laser lift-off or the like. Figure 8 Process S8).

[0062] In the manufacture of pressure sensors, a sheet-like pressure-sensitive layer is sometimes formed by placing it on top of the sensing electrode. However, in this case, the pressure-sensitive layer is sometimes misaligned from the desired location, which can reduce the reliability of the pressure sensor. Furthermore, the method of fixing the pressure-sensitive layer to the sensing electrode can also be problematic.

[0063] In this embodiment, a pressure-sensitive layer is formed by applying a pressure-sensitive layer material onto the detection electrode using a printing method. Therefore, it is possible to prevent the pressure-sensitive layer from being misaligned from the desired location, and furthermore, it eliminates the need for other methods to fix the pressure-sensitive layer to the detection electrode.

[0064] Therefore, according to this embodiment, a method for manufacturing a pressure sensor that can suppress the reduction in reliability can be provided.

[0065] (Second Implementation) Figure 9 This is a top view showing an example configuration of the pressure sensor 1 according to the second embodiment. Descriptions of configurations identical to those in the first embodiment described above are omitted by reference to the previous description. Here, the detection unit 2 of the pressure sensor 1 will be described. Figure 9 In the text, the protective layer 90 is omitted.

[0066] The pressure sensor 1 has multiple detection areas R, a partition 80, and a common electrode 60 (not shown). Figure 9 In the example shown, multiple detection regions R are arranged in the first direction X and the second direction Y.

[0067] Each of the multiple detection regions R has a detection electrode 50, a pressure-sensitive layer 70, and a transistor 30 (not shown). The pressure-sensitive layer 70 overlaps with the detection electrode 50. Figure 9 In the example shown, the pressure-sensitive layer 70 has a rectangular shape of the same size as the detection electrode 50, but it is not limited to this; the pressure-sensitive layer 70 may also have an area smaller than that of the detection electrode 50.

[0068] exist Figure 9 In the example shown, the partition 80 includes a plurality of first partitions 80a arranged in the first direction X and extending along the second direction Y, and a plurality of second partitions 80b arranged in the second direction Y and extending along the first direction X. Two first partitions 80a are disposed between adjacent pressure-sensitive layers 70 in the first direction X. Two second partitions 80b are disposed between adjacent pressure-sensitive layers 70 in the second direction Y. The intersecting first partitions 80a and second partitions 80b are connected to each other. Thus, the partition 80 is generally formed as a lattice surrounding the plurality of pressure-sensitive layers 70. The partition 80 includes a plurality of openings AP1 that overlap with the pressure-sensitive layers 70. Additionally, the partition 80 also includes a plurality of openings AP2 that do not overlap with the pressure-sensitive layers 70. Figure 9 In the example shown, the opening AP1 has a rectangular shape with the same size as the pressure-sensitive layer 70.

[0069] Figure 10 It is along Figure 9 A schematic cross-sectional view of the pressure sensor 1 along the XX line. Description of the same configuration as in the first embodiment described above is omitted by reference to the above description.

[0070] The pressure sensor 1 includes a substrate 10, an insulating layer 20, multiple transistors 30, an insulating layer 40, multiple detection electrodes 50, a common electrode 60, multiple pressure-sensitive layers 70, a partition wall 80, and a protective layer 90.

[0071] Multiple detection electrodes 50 are each disposed on surface 40B according to their respective detection regions R. Multiple pressure-sensitive layers 70 are each formed according to their respective detection regions R. Pressure-sensitive layers 70 are disposed on the detection electrodes 50. Figure 10 In the example shown, the pressure-sensitive layer 70 covers the detection electrode 50.

[0072] The adjacent 80 is positioned on surface 40B. Figure 10In the example shown, two first partition walls 80a are disposed on surface 40B between two adjacent pressure-sensitive layers 70. Each of the first partition walls 80a has a side surface 81S opposite to the pressure-sensitive layer 70 and a side surface 82S opposite to the side surface 81S. The side surface 81S is separated from the side surface 81S of the other first partition wall 80a by 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 disposed in the opening AP1.

[0073] The common electrode 60 covers each of the multiple pressure-sensitive layers 70. Figure 10 In the example shown, the common electrode 60 covers each of the plurality of pressure-sensitive layers 70 and the partitions 80, and covers the entire surface of the pressure sensor 1. The common electrode 60 is positioned opposite each of the plurality of detection electrodes 50 in the third direction Z, separated by the pressure-sensitive layers 70.

[0074] A protective layer 90 covers the common electrode 60. The protective layer 90 has an input surface 1a on the side opposite to the surface facing the substrate 10. The common electrode 60 is, for example, a metal film formed on the side of the protective layer 90 opposite to the input surface 1a. It should be noted that the pressure sensor 1 may also lack a protective layer 90; in this case, the side of the common electrode 60 opposite to the surface facing the substrate 10 becomes the input surface 1a.

[0075] Thus, in the pressure sensor 1 according to the second embodiment, each of the plurality of detection electrodes 50 is arranged opposite to the common electrode 60. That is, the pressure sensor 1 according to the second embodiment has so-called opposing type electrodes.

[0076] Next, the manufacturing method of the pressure sensor 1 according to the second embodiment will be described. Descriptions of the same configuration as the manufacturing method of the pressure sensor 1 according to the first embodiment described above will be omitted by reference to the above description. Figures 11-13 This is a diagram illustrating an example of the manufacturing method of pressure sensor 1. Figures 11-13 A cross-section of a portion of the detection section 2 of the pressure sensor 1 is shown.

[0077] In the manufacture of pressure sensor 1, firstly, a substrate 10 is formed on a support substrate 11, and an insulating layer 20 is formed on the substrate 10. Figure 11 Step S1). After step S1, a transistor 30 is formed on the insulating layer 20, and an insulating layer 40 covering the transistor 30 is formed. Figure 11 Step S2). After step S2, a detection electrode 50 is formed on the insulating layer 40. Figure 11(Step S3). The detection electrode 50 is formed, for example, by patterning a metal film formed on the insulating layer 40 using sputtering or the like. The detection electrode 50 can also be formed, for example, by coating the insulating layer 40 with silver nano-ink or a conductive polymer using a printing method.

[0078] After process S3, an insulating layer 81 is formed on the insulating layer 40 to form the basis of the partition wall 80. Figure 12 Step S4). The insulating layer 81 covers the detection electrode 50. After step S4, an opening AP1 is formed in the insulating layer 81, forming a partition 80 ( Figure 12 Process S5).

[0079] After process S5, a pressure-sensitive layer 70 is formed at the opening AP1. Figure 12 (Step S6). The pressure-sensitive layer 70 is formed by applying a pressure-sensitive layer material onto the detection electrode 50, for example, using printing methods 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, to the area surrounded by the partition wall 80 when viewed from above, thereby forming the pressure-sensitive layer 70 in that area. This prevents the pressure-sensitive layer material from being applied to undesirable areas and inhibits the expansion of the pressure-sensitive layer material before curing.

[0080] After process S6, a common electrode 60 is formed on the pressure-sensitive layer 70 and the partition 80. Figure 13 (Process S7). The common electrode 60 is formed, for example, by sputtering. The common electrode 60 can also be formed, for example, by coating silver nano-ink and conductive polymer onto the pressure-sensitive layer 70 and the spacer 80 using a printing method.

[0081] After process S7, a protective layer 90 is formed on the common electrode 60, thereby manufacturing the pressure sensor 1. Figure 13 (Step S8). The protective layer 90 can be formed, for example, by attaching a film-like protective layer 90 to the common electrode 60. Alternatively, the protective layer 90 can be formed using CVD, printing, or the like. Alternatively, a metal film can be formed on one side of the film-like protective layer 90 to form the common electrode 60, and the side of the common electrode 60 with the protective layer 90 formed can be attached to the pressure-sensitive layer 70, thereby simultaneously forming the protective layer 90 and the common electrode 60. After step S8, the support substrate 11 can be peeled off and removed from the substrate 10 using laser lift-off processing or the like. Figure 13 Process S9).

[0082] In the manufacturing method of the pressure sensor 1 according to this second embodiment, the same effect as in the first embodiment can also be obtained.

[0083] As explained above, according to this embodiment, a method for manufacturing a pressure sensor that can suppress the reduction in reliability can be provided.

[0084] It should be noted that the present invention is not limited to the embodiments described above. During implementation, the constituent elements can be modified to embody the invention without departing from its spirit. Furthermore, various inventions can be formed by appropriate combinations of the multiple constituent elements disclosed in each embodiment. For example, several constituent elements may be deleted from all the constituent elements shown in each embodiment. In addition, constituent elements relating to different embodiments can be appropriately combined.

Claims

1. A method for manufacturing a pressure sensor, wherein, Transistors are formed above the support substrate. An insulating layer is formed to cover the transistor. A common electrode and a detection electrode connected to the transistor are formed on the insulating layer. A pressure-sensitive layer is formed on the detection electrode by applying a pressure-sensitive layer material using a printing method.

2. The method for manufacturing a pressure sensor as described in claim 1, wherein, The printing method is inkjet printing, screen printing, or flexographic printing.

3. The method for manufacturing a pressure sensor as described in claim 1, wherein, The pressure-sensitive layer material is a material containing conductive materials.

4. The method for manufacturing a pressure sensor as described in claim 3, wherein, The pressure-sensitive layer material is a material whose resistance value changes according to the pressure.

5. The method for manufacturing a pressure sensor as described in claim 3, wherein, The pressure-sensitive layer material contains silver nano-ink or carbon paste.

6. The method for manufacturing a pressure sensor as described in claim 1, wherein, Before forming the pressure-sensitive layer, a partition is formed on the insulating layer. The pressure-sensitive layer is formed in the area surrounded by the partition wall.

7. The method for manufacturing a pressure sensor as described in claim 6, wherein, The partition is formed of an insulating material.

8. The method for manufacturing a pressure sensor as described in claim 7, wherein, The partition is formed of an acrylic resin or an epoxy resin.

9. The method for manufacturing a pressure sensor as described in claim 1, wherein, After the pressure-sensitive layer is formed, the support substrate is peeled off.

10. A method for manufacturing a pressure sensor, wherein, Transistors are 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 detection electrode by applying a pressure-sensitive layer material using a printing method. A common electrode is formed on the pressure-sensitive layer.

11. The method for manufacturing a pressure sensor as described in claim 10, wherein, The printing method is inkjet printing, screen printing, or flexographic printing.

12. The method for manufacturing a pressure sensor as described in claim 10, wherein, The pressure-sensitive layer material is a material containing conductive materials.

13. The method for manufacturing a pressure sensor as described in claim 12, wherein, The pressure-sensitive layer material is a material whose resistance value changes according to the pressure.

14. The method for manufacturing a pressure sensor as described in claim 12, wherein, The pressure-sensitive layer material contains silver nano-ink or carbon paste.

15. The method for manufacturing a pressure sensor as described in claim 10, wherein, Before forming the pressure-sensitive layer, a partition is formed on the insulating layer. The pressure-sensitive layer is formed in the area surrounded by the partition wall.

16. The method for manufacturing a pressure sensor as described in claim 15, wherein, The partition is formed of an insulating material.

17. The method of manufacturing a pressure sensor as described in claim 16, wherein, The partition is formed of acrylic resin or epoxy resin.

18. The method for manufacturing a pressure sensor as described in claim 10, wherein, After the pressure-sensitive layer is formed, the support substrate is peeled off.

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