Pressure sensors and electronic equipment

Abstract

The present application discloses a pressure sensor and an electronic device, belonging to the field of electronic technology. In the pressure sensor, the first electrode and the second electrode included in the pressure sensing unit are both located between the substrate and the piezoresistive film. In this way, the spacing between the first electrode and the second electrode will not be affected by the deformation, film thickness or surface unevenness of the piezoresistive film. Furthermore, it is ensured that when the piezoresistive film is pressurized, the stability of the current intensity in the current path formed between the first electrode and the second electrode is good, and accordingly, the pressure detection circuit can reliably detect the pressure applied to the pressure sensor according to the potential of the first electrode.

Description

Technical Field

[0001] The present application relates to the field of electronic technology, and in particular to a pressure sensor and an electronic device. Background Art

[0002] A pressure sensor is a device that senses pressure and converts the sensed pressure into an electrical signal. Common pressure sensors include piezoresistive pressure sensors.

[0003] In the related art, the piezoresistive pressure sensor generally includes: a substrate, and a first electrode, a piezoresistive film, and a second electrode located on the substrate and stacked in sequence in a direction away from the substrate. Among them, the first electrode is coupled to the pressure detection circuit, and the second electrode is grounded. Under the stress of the piezoresistive film, a current path can be generated between the first electrode and the second electrode. The current flowing in the current path will change the potential of the second electrode, and the intensity of the current is related to the distance between the first electrode and the second electrode. The pressure detection circuit can collect the potential of the first electrode and realize pressure detection based on the collected potential.

[0004] However, in the related art, the distance between the first electrode and the second electrode of the piezoresistive pressure sensor is easily affected by factors such as deformation, film thickness or surface unevenness of the piezoresistive film and thus changes, resulting in low reliability of pressure detection. Summary of the invention

[0005] The embodiment of the present application provides a pressure sensor and an electronic device, which can solve the problem of low reliability of pressure detection in the related art. The technical solution is as follows:

[0006] In one aspect, a pressure sensor is provided, the pressure sensor comprising:

[0007] substrate;

[0008] a piezoresistive film located on the substrate;

[0009] and, a plurality of pressure sensing units located between the piezoresistive film and the substrate, at least one of the pressure sensing units comprising: a gating circuit, and a first electrode and a second electrode arranged at intervals;

[0010] Among them, the orthographic projection of the first electrode on the substrate and the orthographic projection of the second electrode on the substrate are both located within the orthographic projection of the piezoresistive film on the substrate; the second electrode is coupled to the reference power supply terminal, the gating circuit is coupled to the first electrode and the pressure detection circuit respectively, and the gating circuit is used to control the on-off between the pressure detection circuit and the first electrode.

[0011] Optionally, the first electrode and the second electrode are located in the same layer.

[0012] Optionally, both the first electrode and the second electrode are strip electrodes, and the first electrode and the second electrode are parallel to each other.

[0013] Optionally, both the first electrode and the second electrode are interdigital electrodes, and the first electrode and the second electrode are arranged in an alternating manner.

[0014] Optionally, one of the first electrode and the second electrode half surrounds the other electrode, and the first electrode and the second electrode are concentric.

[0015] Optionally, the orthographic projection of the one electrode on the substrate is a circular ring with an opening, and the orthographic projection of the other electrode on the substrate is a circle;

[0016] Alternatively, the orthographic projection of the one electrode on the substrate is a square ring with an opening, and the orthographic projection of the other electrode on the substrate is a rectangle.

[0017] Optionally, the gating circuit is coupled to the pressure detection circuit via a detection line, and the gating circuit is also coupled to a gate line;

[0018] The gating circuit is used to control the connection between the detection line and the first electrode in response to a gate driving signal provided by the gate line.

[0019] Optionally, the plurality of pressure sensing units are arranged in an array; the gating circuits included in the pressure sensing units in the same row are coupled to the same gate line, the gating circuits included in the pressure sensing units in the same column are coupled to the same detection line, and the second electrodes included in the pressure sensing units in the same column are coupled to the reference power supply terminal through the same reference power supply line;

[0020] Among them, the reference power line and the detection line both extend in the column direction, the gate line extends in the row direction, and intersects with the reference power line and the detection line and is insulated from each other; the orthographic projection of the selection circuit on the substrate does not overlap with the orthographic projection of the first intersection on the substrate, and does not overlap with the orthographic projection of the second intersection on the substrate; the first intersection is the intersection of the gate line and the detection line, and the second intersection is the intersection of the selection circuit, the gate line and the reference power line.

[0021] Optionally, both the first electrode and the second electrode are located between the reference power line and the detection line, and are located between two adjacent gate lines.

[0022] Optionally, the gating circuit includes: a transistor;

[0023] The gate of the transistor is coupled to the gate line, the first electrode of the transistor is coupled to the detection line, and the second electrode of the transistor is coupled to the first electrode;

[0024] Among the first and second electrodes of the transistor, one electrode is a source electrode and the other electrode is a drain electrode.

[0025] Optionally, a material of any electrode among the first electrode and the second electrode includes a metal material.

[0026] Optionally, the substrate is a flexible substrate.

[0027] Optionally, the pressure sensor further includes: a packaging layer located on the piezoresistive film.

[0028] Optionally, the encapsulation layer is a flexible encapsulation layer.

[0029] On the other hand, an electronic device is provided, the electronic device comprising: a pressure detection circuit, and the pressure sensor as described in the above aspect;

[0030] The pressure detection circuit is coupled to a strobe circuit in the pressure sensor, and the pressure detection circuit is used to detect the pressure applied to the pressure sensor according to the potential transmitted by the strobe circuit.

[0031] In summary, the beneficial effects brought about by the technical solution provided in the embodiments of the present application include at least:

[0032] A pressure sensor and an electronic device are provided. In the pressure sensor, a first electrode and a second electrode included in a pressure sensing unit are both located between a substrate and a piezoresistive film. In this way, the spacing between the first electrode and the second electrode will not change due to interference from factors such as deformation, film thickness, or surface unevenness of the piezoresistive film. Furthermore, when the piezoresistive film is pressurized, the stability of the current intensity in the current path formed between the first electrode and the second electrode is ensured to be good, and accordingly, the pressure detection circuit can reliably detect the pressure applied to the pressure sensor according to the potential of the first electrode. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0034] Figure 1 is a schematic structural diagram of a pressure sensor including a single bottom electrode provided in an embodiment of the present application;

[0035] Figure 2 This is a schematic diagram of the principle of generating a pressure signal corresponding to a single bottom electrode provided in an embodiment of the present application;

[0036] Figure 3 is a schematic structural diagram of a pressure sensor including double bottom electrodes provided in an embodiment of the present application;

[0037] Figure 4 This is a schematic diagram of the principle of generating a pressure signal corresponding to a double bottom electrode provided in an embodiment of the present application;

[0038] Figure 5 is a simplified structural diagram of a pressure sensor including double bottom electrodes provided in an embodiment of the present application;

[0039] Figure 6 is a schematic diagram of the structure of a first electrode and a second electrode provided in an embodiment of the present application;

[0040] Figure 7 is a schematic diagram of the structure of another first electrode and a second electrode provided in an embodiment of the present application;

[0041] Figure 8 is a schematic diagram of the structure of another first electrode and a second electrode provided in an embodiment of the present application;

[0042] Fig. 9 is a structural schematic diagram of a gating circuit provided in an embodiment of the present application;

[0043] Fig.10 is a structural schematic diagram of another gating circuit provided in an embodiment of the present application;

[0044] Fig.11 is a schematic structural diagram of another pressure sensor including double bottom electrodes provided in an embodiment of the present application;

[0045] Fig.12 is a schematic structural diagram of another pressure sensor including double bottom electrodes provided in an embodiment of the present application;

[0046] Fig.13 It is a local structural layout of a pressure sensor including double bottom electrodes provided in an embodiment of the present application;

[0047] Fig.14 It is a structural layout of a gating circuit provided in an embodiment of the present application;

[0048] Fig.15 It is a structural layout of a double bottom electrode provided in an embodiment of the present application;

[0049] Fig.16 It is a structural schematic diagram of an electronic device provided in an embodiment of the present application;

[0050] Fig.17 This is a structural diagram of an electronic device provided in an embodiment of the present application.

[0051] The descriptions of the various reference numerals in the accompanying drawings are as follows:

[0052] 00-pressure sensor, 10-pressure detection circuit;

[0053] 01-substrate, 02-piezoresistive film, 03-pressure sensing unit, 04-packaging layer;

[0054] 031- gating circuit, 032- first electrode, 033- second electrode;

[0055] K1-transistor, G1-gate line, S1-detection line, V1-reference power line, GND-ground terminal. DETAILED DESCRIPTION

[0056] In order to make the objectives, technical solutions and advantages of the present application clearer, the implementation methods of the present application will be further described in detail below with reference to the accompanying drawings.

[0057] With the development of science and technology, pressure sensors that can detect the pressing position and pressure are widely used in various fields to achieve different functions. For example, pressure sensors are used in the currently popular artificial intelligence fields such as robots and the Internet to realize tactile perception functions. In the field of artificial intelligence, pressure sensors must have the advantages of high sensitivity, wide pressure detection range, fast response capability, high-sensitivity pressure sensing array point layout, large size or adjustable size, etc., to ensure the accuracy and real-time nature of tactile perception data collection.

[0058] At present, common pressure sensors include: capacitive pressure sensors, piezoelectric pressure sensors, TENG-type pressure sensors that rely on frictional power generation, and piezoresistive pressure sensors. Among them, because capacitive pressure sensors, piezoelectric pressure sensors, and capacitive pressure sensors are limited by essential factors such as materials and device structures, their sensing sensitivity is poor, and the signal stability during operation is poor, so piezoresistive pressure sensors have become the hope for realizing tactile perception functions. In related technologies, the circuits included in piezoresistive pressure sensors are common in passive array circuits and active array circuits. And because the array point density of active array circuits can be set higher than that of passive array circuits, and the sensitivity of sensing pressure is better, the array circuits included in pressure sensors that realize tactile perception functions are mostly active array circuits.

[0059] For example, refer to Figure 1 , which shows a piezoresistive pressure sensor including an active array circuit. In the piezoresistive pressure sensor, two electrodes for forming a current path under the stress of the piezoresistive film are respectively located on the upper and lower sides of the piezoresistive film. Figure 1 One electrode on the side of the piezoresistive film (not shown) is called the bottom electrode, and the other electrode on the side of the piezoresistive film away from the substrate is called the top electrode. That is, the piezoresistive pressure sensor in the related art belongs to a single bottom electrode structure. Figure 2 When pressure is applied to the piezoresistive film, a current path will be generated between the upper electrode and the bottom electrode. Moreover, according to tests, the intensity of the current in the current path is affected by the distance between the upper electrode and the bottom electrode. However, in the pressure sensor with a single bottom electrode structure, the distance between the upper electrode and the bottom electrode is easily affected by factors such as the deformation of the piezoresistive film, the misalignment between the layers (such as the piezoresistive film, the upper electrode and the bottom electrode), the uneven thickness of the film, and the protrusions or depressions on the surface, which leads to poor stability of the intensity of the current in the current path. Based on this, the reliability of the pressure sensor in the related art in sensing pressure is low and the stability is poor.

[0060] The embodiment of the present application provides a piezoresistive pressure sensor, which not only has high detection sensitivity, wide detection range, and fast response time, but also can achieve a high-density pressure sensing array point layout, the size can be set larger, and the reliability of detecting pressure is high.

[0061] Figure 3 Schematic diagram of a pressure sensor provided by an embodiment of the present disclosure. Figure 3 As shown, the pressure sensor includes: a substrate 01 , a piezoresistive film 02 located on the substrate 01 (ie, located on one side of the substrate 01 ), and a plurality of pressure sensing units 03 located between the piezoresistive film 02 and the substrate 01 .

[0062] At least one pressure sensing unit 03 includes: a gate circuit 031, and a first electrode 032 and a second electrode 033 arranged at intervals. Here, the interval arrangement may refer to Figure 3 There is a gap between the first electrode 032 and the second electrode 033, and no material is filled in the gap. Alternatively, the gap may be filled with an insulating material. In addition, since the first electrode 032 and the second electrode 033 are both located on the side of the piezoresistive film 02 close to the substrate 01, the first electrode 032 and the second electrode 033 can be called double bottom electrodes. That is, the pressure sensor 03 recorded in the embodiment of the present application is a piezoresistive pressure sensor with a double bottom electrode structure.

[0063] The orthographic projection of the first electrode 032 on the substrate 01 and the orthographic projection of the second electrode 033 on the substrate 01 are both located within the orthographic projection of the piezoresistive film 02 on the substrate 01. That is, the piezoresistive film 02 covers the first electrode 032 and the second electrode 033. The second electrode 033 is connected to the reference power supply terminal ( Figure 3 The selection circuit 031 is coupled to the first electrode 032 and the pressure detection circuit ( Figure 3The voltage regulator 032 is coupled to the first electrode 032 (not shown), and the selection circuit 031 is used to control the on-off between the pressure detection circuit and the first electrode 032.

[0064] By way of example, the reference power supply terminal may be a ground terminal GND, or may be another power supply terminal (eg, VGL) that can provide a low potential. Figure 3 Only one pressure sensing unit 03 is schematically shown. Of course, in some embodiments, each pressure sensing unit 03 included in the pressure sensor can be Figure 3 The structure shown.

[0065] In the examples of this application, refer to Figure 4 It can be seen that when pressure is applied to the piezoresistive film 02, a current path is formed between the first electrode 032 and the second electrode 033. Moreover, the resistance value of the resistor included in the piezoresistive film 02 will change, that is, the piezoresistive film 02 will undergo a resistance change phenomenon, and the resistance change phenomenon will act on the first electrode 032 through the current path. Then, after the selection circuit 031 controls the pressure detection circuit to be connected to the first electrode, the pressure detection circuit can reliably detect the pressure applied to the pressure sensor according to the detected current strength.

[0066] Recombination Figure 3 and Figure 4 It can be seen that, since the first electrode 032 and the second electrode 033 in the pressure sensor provided by the embodiment of the present application are both located between the piezoresistive film 02 and the substrate 01, the distance between the first electrode 032 and the second electrode 033 will not be affected by the deformation of the piezoresistive film 02, the misalignment between the layers, the uneven thickness of the film, the surface protrusions or depressions, etc., and will not change, that is, the distance between the first electrode 032 and the second electrode 033 can be fixed. In this way, combined with the above-mentioned embodiment, it can be seen that the stability of the current intensity in the current path formed between the first electrode 032 and the second electrode 033 is good, and accordingly, the pressure sensor has high reliability and high stability in detecting pressure.

[0067] In summary, an embodiment of the present application provides a pressure sensor. In the pressure sensor, the first electrode and the second electrode included in the pressure sensing unit are both located between the substrate and the piezoresistive film. In this way, the spacing between the first electrode and the second electrode will not change due to interference from factors such as deformation, film thickness or surface unevenness of the piezoresistive film. Furthermore, it is ensured that when the piezoresistive film is under pressure, the stability of the current intensity in the current path formed between the first electrode and the second electrode is good, and accordingly, the pressure detection circuit can reliably detect the pressure applied to the pressure sensor based on the potential of the first electrode.

[0068] Optional, Figure 5 is a simplified structural diagram of a pressure sensor provided in an embodiment of the present application. Figure 5It can be seen that the pressure sensor may further include: a packaging layer 04 located on the piezoresistive film 02 (ie, the side of the piezoresistive film 02 away from the substrate 01 ). The packaging layer 04 may be used to package and protect the piezoresistive film 02 and the pressure sensing unit 03 .

[0069] Optionally, the material of the encapsulation layer 04 may be a flexible material, such as a polyimide (PI) material. Of course, in some embodiments, the material of the encapsulation layer 04 may also be a non-flexible material, such as glass or silicon wafer.

[0070] In addition, reference Figure 1 , for a pressure sensor with a single bottom electrode structure, it may also include a packaging layer located above the upper electrode (i.e., the upper electrode is away from the side of the piezoresistive film), and a gating circuit located above the piezoresistive film (i.e., the side of the piezoresistive film is away from the upper electrode). The gating circuit is coupled to the bottom electrode. The upper electrode may include a metal drainage layer and a wire coupled to a reference power supply terminal, and the metal drainage layer and the wire may be deposited and patterned on the surface of the piezoresistive film or the surface of the packaging layer. In other words, for a pressure sensor with a single bottom electrode structure, it may include a substrate, and four parts including a single bottom electrode transistor pressure sensing array circuit (i.e., a structure including a single bottom electrode and a gating circuit), a piezoresistive film, a metal drainage layer, and a packaging layer stacked sequentially in a direction away from the substrate. And the reference Figure 5 It can be seen that the pressure sensor with a double bottom electrode structure described in the embodiment of the present application only includes a substrate, a double bottom electrode transistor pressure sensing array circuit (i.e., a structure including double bottom electrodes and a gating circuit) stacked in sequence in a direction away from the substrate, a piezoresistive film, and a packaging layer, but does not include a metal drainage layer. Figure 1 and Figure 5 It can be seen that the embodiment of the present application, by setting the pressure sensor to a piezoresistive pressure sensor with a double bottom electrode structure, avoids the need to add a separate metal conductive layer in addition to the piezoresistive film in the manufacturing process, simplifies the assembly process steps, and saves manufacturing costs compared to the related art.

[0071] Optionally, the substrate 01 described in the embodiment of the present application may be a flexible substrate 01. For example, it may be a PI substrate. Alternatively, the material of the flexible substrate 01 may include: polyethylene terephthalate (PET) or polydimethylsiloxane (PDMS).

[0072] Optionally, the materials of the first electrode 032 and the second electrode 033 described in the embodiment of the present application may both include metal materials.

[0073] Optionally, in an embodiment of the present application, the first electrode 032 and the second electrode 033 may be located in the same layer. Being located in the same layer may mean that the first electrode 032 and the second electrode 033 are in the same dimension or the same plane. In this way, the first electrode 032 and the second electrode 033 arranged at intervals may be formed simultaneously using the same mask plate and a single patterning process. A single patterning process may include multiple exposure, development or etching processes. That is, multiple elements, components, structures and / or parts located in the "same layer" are made of the same material and are formed by the same patterning process. In this way, production costs can be reduced and production efficiency can be improved.

[0074] Optionally, the structure of the double bottom electrode described in the embodiment of the present application can be flexible, for example, it can be set to a desired pattern according to the piezoresistive material used by the piezoresistive film 02 and the signal stability requirements. For example, under the premise that the first electrode 032 and the second electrode 033 are located in the same layer, the structure of the first electrode 032 and the second electrode 033 can satisfy at least one of the following structures:

[0075] As an optional implementation: Combine Figure 3 and Figure 4 The first electrode 032 and the second electrode 033 described in the embodiment of the present application may both be strip electrodes, and the first electrode 032 and the second electrode 033 may be parallel to each other. That is, the first electrode 032 and the second electrode 033 may be parallel electrodes.

[0076] As another optional implementation: refer to Figure 6 The first electrode 032 and the second electrode 033 may both be interdigital electrodes, and the first electrode 032 and the second electrode 033 may be alternately arranged.

[0077] As another optional implementation manner: among the first electrode 032 and the second electrode 033, one electrode may half surround the other electrode, and the first electrode 032 and the second electrode 033 may be concentric.

[0078] For example, refer to Figure 7 , an electrode (e.g., Figure 7 The orthographic projection of the first electrode 032 shown on the substrate 01 may be a circular ring with an opening, and another electrode (eg, Figure 7 The orthographic projection of the second electrode 033 shown on the substrate 01 may be circular.

[0079] For example, refer to Figure 8 , an electrode (e.g., Figure 8 The orthographic projection of the first electrode 032 shown on the substrate 01 may be a square ring with an opening, and another electrode (eg, Figure 8 The orthographic projection of the second electrode 033 shown on the substrate 01 may be rectangular.

[0080] Of course, in some embodiments, the first electrode 032 and the second electrode 033 are not limited to the above shapes. For example, one of the first electrode 032 and the second electrode 033 can surround the other electrode. Figure 7 , the orthographic projection of the second electrode 033 on the substrate 01 can be a closed circular ring.

[0081] It should be noted that the embodiment of the present application does not limit the size of the first electrode 032 and the second electrode 033 , which can be flexibly set according to the piezoresistive material used in the piezoresistive film 02 and the signal stability requirements.

[0082] Optional, Fig. 9 Schematic diagram of a gating circuit provided in an embodiment of the present application. Fig. 9 As shown, the gating circuit 031 can be connected to the pressure detection circuit ( Fig. 9 The gate circuit 031 may be coupled to the gate line G1 and the gate line D2 (not shown), and the gate circuit 031 may also be coupled to the gate line G1. The gate circuit 031 may be used to control the connection between the detection line D1 and the first electrode 032 in response to the gate driving signal provided by the gate line G1.

[0083] For example, the gating circuit 031 can control the detection line D1 to be connected to the first electrode 032 when the potential of the gate drive signal provided by the gate line G1 is the first potential. At this time, the potential of the first electrode 032 can be transmitted to the pressure detection circuit via the gating circuit 031. That is, the gating circuit 031 can transmit the potential of the first electrode 032 to the pressure detection circuit at this time. And, the gating circuit 031 can control the detection line D1 to be disconnected from the first electrode 032 when the potential of the gate drive signal provided by the gate line G1 is the second potential. Optionally, the first potential can be an effective potential, and the second potential can be an invalid potential.

[0084] Optional, Fig.10 is a schematic diagram of the structure of another gating circuit provided in an embodiment of the present application. Fig.10 As shown, the gating circuit 031 may include: a transistor T1.

[0085] The gate of the transistor T1 may be coupled to the gate line G1, the first electrode of the transistor T1 may be coupled to the detection line D1, and the second electrode of the transistor T1 may be coupled to the first electrode 032 ( Fig.10 In addition, Fig.10 The piezoresistive (PSR) film 02 and the ground terminal GND are also schematically shown. The ground terminal GND can be used as a reference power supply terminal.

[0086] Optionally, one of the first electrode and the second electrode of the transistor T1 may be a source electrode, and the other electrode may be a drain electrode. Fig.11 As can be seen from another pressure sensor shown, in the embodiment of the present application, the first electrode of the transistor T1 is the drain electrode, and the second electrode of the transistor T1 is the source electrode. In other words, the source electrode of the transistor T1 can be coupled to the first electrode 032, and the drain electrode of the transistor T1 can be coupled to the detection line D1. In this way, the detection line D1 can also be called a drain line.

[0087] In addition, reference Fig.11 It can also be seen that an insulating layer is provided between the transistor T1 included in the gating circuit 031 and the piezoresistive film 02. The insulating layer can isolate the signal interference between the piezoresistive film 02 and the transistor T1, thereby protecting the transistor T1.

[0088] It should be noted that, combined with Fig.11 It can be seen that the transistor T1 recorded in the embodiment of the present application is a bottom-gate transistor, that is, the gate is located below the source and the drain and is in contact with the substrate 01. Of course, in some embodiments, the transistor T1 can also be a top-gate transistor, that is, the gate is located above the source and the drain and is not in contact with the substrate 01. In addition, the channel width-to-length ratio of the transistor T1 recorded in the embodiment of the present application can be flexibly adjusted according to the manufacturing process and the dielectric material used.

[0089] Optionally, the transistor T1 described in the embodiment of the present application may be Fig.10 The transistor shown may also be of other types of structures, such as a Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET), that is, a MOS transistor.

[0090] Optionally, the transistor T1 described in the embodiment of the present application may be an N-type transistor. On this basis, the first potential described in the above embodiment may be a high potential relative to the second potential (i.e., the first potential is greater than the second potential). Of course, in some embodiments, the transistor T1 may also be a P-type transistor. On this basis, the first potential may be a low potential relative to the second potential (i.e., the first potential is less than the second potential).

[0091] Optionally, the gating circuit 031 described in the embodiment of the present application may be the transistor described in the above embodiment, or may also be a selector device.

[0092] Optional, Fig.12 is a schematic diagram of the structure of another pressure sensor provided in an embodiment of the present application. Fig.12As shown, the multiple pressure sensing units 03 included in the pressure sensor 00 can be arranged in an array. That is, multiple rows and columns of pressure sensing units 03 can be included. On this basis, the gating circuit 031 included in each pressure sensing unit 03 located in the same row can be coupled to the same gate line G1, the gating circuit 031 included in each pressure sensing unit 03 located in the same column can be coupled to the same detection line D1, and the second electrode 033 included in each pressure sensing unit 03 located in the same column can be coupled to the reference power supply terminal (such as the ground terminal GND) through the same reference power supply line V1. In this way, the wiring can be simplified and the cost can be saved.

[0093] Optional, with Fig.12 Take the structure shown as an example, Fig.13 The figure shows a partial structural layout of a pressure sensor. Fig.12 and Fig.13 It can be seen that the reference power line V1 and the detection line D1 can both extend in the column direction, the gate line G1 can extend in the row direction, and the gate line G1 intersects with the reference power line V1 and the detection line D1 and is insulated from each other. The intersection point where the gate line G1 intersects with the detection line D1 can be called the first intersection point P1, and the intersection point where the gate line G1 intersects with the reference power line V1 can be called the second intersection point P2. The orthographic projection of the gating circuit 031 (i.e., the transistor T1) on the substrate 01 does not overlap with the orthographic projection of the first intersection point P1 on the substrate 01, and the orthographic projection of the gating circuit 031 on the substrate 01 does not overlap with the orthographic projection of the second intersection point P2 on the substrate 01. That is, the transistor T1 does not overlap with the intersection area of ​​the horizontal and vertical signal lines.

[0094] In the related art, transistor T1 is generally set in the horizontal and vertical intersection area of ​​the signal line. After testing, it is found that this not only increases the manufacturing difficulty, but also the fine burrs between the stacked layers easily cause signal short circuits, the yield rate of the pressure sensor is poor, and it is not easy to realize a high-density array circuit. It can be seen that the embodiment of the present application not only reduces the manufacturing difficulty and improves the yield rate of the pressure sensor by moving the transistor T1 out of the intersection area, but also can be set as a high-density array circuit.

[0095] Optional, continue to refer to Fig.13 It can be seen that the pressure sensing unit 03 can be divided into two parts. One part is the circuit part of the transistor T1, which can be used as a switch to select the first electrode 032 and the detection line D1. The other part is the double bottom electrode part including the first electrode 032 and the second electrode 033, which can contact the piezoresistive film 02 to receive the current intensity change signal (i.e., resistance change signal) of the piezoresistive film 02 subjected to the force passing through the two electrodes.

[0096] For example, Fig.14 The structure of the circuit part of transistor T1 is shown. Fig.15 The structure of the double bottom electrode part is shown. Fig.11 and Fig.14 It can be seen that the transistor T1 may include a source electrode (ie, source), a drain electrode (ie, drain), a gate electrode (ie, gate), and a dielectric layer located between the source electrode and the drain electrode. Fig.15 It can be further seen that the double bottom electrodes described in the embodiments of the present application can be parallel-plate electrodes that are strip-shaped and parallel to each other.

[0097] In combination with the above embodiments, it can be known that the piezoresistive pressure sensor recorded in the embodiment of the present application has a higher pressure detection reliability and a lower manufacturing difficulty, and the resolution and yield rate are both high, compared with the pressure sensor of the related art, because a double bottom electrode is provided and the transistor T1 is moved out of the intersection area. The yield rate can generally reach 99.9%. The piezoresistive pressure sensor recorded in the embodiment of the present application has a higher pressure detection sensitivity and a wider pressure detection range than the capacitive pressure sensor of the related art. In addition, in the piezoresistive pressure sensor recorded in the embodiment of the present application, the detection principle of the pressure signal comes from the change in resistance of the piezoresistive film under pressure, rather than from the deformation of the transistor itself to obtain a signal. Compared with obtaining a signal by relying on the transistor channel in a stretched state, the scope of application of the present application is wider.

[0098] Optionally, the circuit layout included in the pressure sensor 00 described in the embodiment of the present application can be made using a semiconductor micromachining flow process, which is not only suitable for experimental small-scale manufacturing, but also suitable for large-scale production, and has technical value in the manufacture of marketed products. The circuit size based on the transistor T1 is adjustable, so that a pressure sensor with the required number of array points (i.e., the number of transistors T1) and resolution can be produced according to the application scenario, that is, the resolution of the pressure sensor can be flexibly adjusted.

[0099] In summary, an embodiment of the present application provides a pressure sensor. In the pressure sensor, the first electrode and the second electrode included in the pressure sensing unit are both located between the substrate and the piezoresistive film. In this way, the spacing between the first electrode and the second electrode will not change due to interference from factors such as deformation, film thickness or surface unevenness of the piezoresistive film. Furthermore, it is ensured that when the piezoresistive film is under pressure, the stability of the current intensity in the current path formed between the first electrode and the second electrode is good, and accordingly, the pressure detection circuit can reliably detect the pressure applied to the pressure sensor based on the potential of the first electrode.

[0100] Fig.16 Schematic diagram of the structure of an electronic device provided in an embodiment of the present application. Fig.16 As shown, the electronic device includes: a pressure detection circuit 10, and Figure 3 , Figure 5, Fig.11 and Fig.12 Any of the pressure sensors 00 shown.

[0101] The pressure detection circuit 10 may be coupled to the gate circuit 031 in the pressure sensor, and the pressure detection circuit 10 is used to detect the pressure applied to the pressure sensor 00 according to the potential transmitted by the gate circuit 031. Fig.17 It can be seen that the pressure detection circuit 10 can be coupled to the drain of the gate circuit 031 through the detection line D1. Fig.17 It is also shown that the gate of the gate circuit 031 is coupled to the gate line G1, and the second electrode 033 is coupled to the reference power line V1.

[0102] Optional, in Fig.16 On the basis of Fig.17 FIG. 1 shows a circuit diagram of an electronic device including a pressure sensor 00. Fig.17 It can be known that the resolution of the pressure sensor 00 provided in the embodiment of the present application can be as high as 0.9 mm, and the pressure sensor can include 2496 transistors T1, that is, can include 2496 pressure sensing units 03. The pressure sensor 00 provided in the embodiment of the present application has a high resolution.

[0103] Optionally, the electronic device described in the embodiment of the present application may be a robot (e.g., an intelligent robot), and the pressure sensor may be disposed on the palm of the robot for the robot to sense pressure. Of course, in some embodiments, the electronic device may also be an electronic device such as an e-book, a mobile phone, or a computer, which is not limited in the embodiment of the present application.

[0104] Optionally, the words “first”, “second” or “third” and similar words recorded in the embodiments of the present application do not indicate any order, quantity or importance, but are only used to distinguish different components.

[0105] Likewise, the words “a” or “an” and the like do not denote a limitation of quantity, but rather denote the presence of at least one.

[0106] “Including” or “comprising” and similar words mean that the elements or objects appearing before “including” or “comprising” include the elements or objects listed after “including” or “comprising” and their equivalents, and do not exclude other elements or objects.

[0107] The terms "connected" or "coupled" and the like are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect.

[0108] “Up”, “down”, “left”, “right”, etc. are only used to indicate relative position relationships. When the absolute position of the described object changes, the relative position relationship may also change accordingly.

[0109] "And / or" indicates that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the objects before and after are in an "or" relationship.

[0110] The above description is only an optional embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A pressure sensor, characterized in that: The pressure sensor comprises: substrate; a piezoresistive film located on the substrate; and, a plurality of pressure sensing units located between the piezoresistive film and the substrate, at least one of the pressure sensing units comprising: a gating circuit, and a first electrode and a second electrode arranged at intervals; The orthographic projection of the first electrode on the substrate and the orthographic projection of the second electrode on the substrate are both located within the orthographic projection of the piezoresistive film on the substrate; the second electrode is coupled to the reference power supply terminal, the gating circuit is coupled to the first electrode and the pressure detection circuit respectively, and the gating circuit is used to control the on-off between the pressure detection circuit and the first electrode; The gating circuit is coupled to the pressure detection circuit through a detection line, and the gating circuit is also coupled to a gate line; the gating circuit includes a transistor, and an insulating layer is provided between the transistor and the piezoresistive film.

2. The pressure sensor according to claim 1, characterized in that: The first electrode and the second electrode are located in the same layer.

3. The pressure sensor according to claim 2, characterized in that: The first electrode and the second electrode are both strip electrodes, and the first electrode and the second electrode are parallel to each other.

4. The pressure sensor according to claim 2, characterized in that: The first electrode and the second electrode are both interdigital electrodes, and the first electrode and the second electrode are arranged in a staggered manner.

5. The pressure sensor according to claim 2, characterized in that: Of the first electrode and the second electrode, one electrode half surrounds the other electrode, and the first electrode and the second electrode are concentric.

6. The pressure sensor according to claim 5, characterized in that: The orthographic projection of the one electrode on the substrate is a ring with an opening, and the orthographic projection of the other electrode on the substrate is a circle; Alternatively, the orthographic projection of the one electrode on the substrate is a square ring with an opening, and the orthographic projection of the other electrode on the substrate is a rectangle.

7. The pressure sensor according to any one of claims 1 to 6, characterized in that: The gating circuit is used for controlling the connection and disconnection between the detection line and the first electrode in response to a gate driving signal provided by the gate line.

8. The pressure sensor according to claim 7, characterized in that: The plurality of pressure sensing units are arranged in an array; the gating circuits included in the pressure sensing units in the same row are coupled to the same gate line, the gating circuits included in the pressure sensing units in the same column are coupled to the same detection line, and the second electrodes included in the pressure sensing units in the same column are coupled to the reference power supply terminal through the same reference power supply line; Among them, the reference power line and the detection line both extend in the column direction, the gate line extends in the row direction, and intersects with the reference power line and the detection line and is insulated from each other; the orthographic projection of the selection circuit on the substrate does not overlap with the orthographic projection of the first intersection on the substrate, and does not overlap with the orthographic projection of the second intersection on the substrate; the first intersection is the intersection of the gate line and the detection line, and the second intersection is the intersection of the selection circuit, the gate line and the reference power line.

9. The pressure sensor according to claim 8, characterized in that: The first electrode and the second electrode are both located between the reference power line and the detection line, and are both located between two adjacent gate lines.

10. The pressure sensor according to claim 7, characterized in that: The gate of the transistor is coupled to the gate line, the first electrode of the transistor is coupled to the detection line, and the second electrode of the transistor is coupled to the first electrode; Among the first and second electrodes of the transistor, one electrode is a source electrode and the other electrode is a drain electrode.

11. The pressure sensor according to any one of claims 1 to 6, characterized in that: A material of any of the first electrode and the second electrode includes a metal material.

12. The pressure sensor according to any one of claims 1 to 6, characterized in that: The substrate is a flexible substrate.

13. The pressure sensor according to any one of claims 1 to 6, characterized in that: The pressure sensor further includes: a packaging layer located on the piezoresistive film.

14. The pressure sensor according to claim 13, characterized in that: The packaging layer is a flexible packaging layer.

15. An electronic device, characterized in that: The electronic device comprises: a pressure detection circuit, and a pressure sensor as claimed in any one of claims 1 to 14; The pressure detection circuit is coupled to a strobe circuit in the pressure sensor, and the pressure detection circuit is used to detect the pressure applied to the pressure sensor according to the potential transmitted by the strobe circuit.

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