A pressure sensing device

Abstract

This invention discloses a pressure sensing device, comprising a circuit board, an elastic layer, a conductive top layer, and a detection circuit. The circuit board has a first electrode and a second electrode that are coplanar and close to each other, with a horizontal capacitance between them. The elastic layer covers the first and second electrodes. The conductive top layer covers the elastic layer and, together with the first and second electrodes, forms vertical capacitances. The conductive top layer is grounded or connected to a reference voltage. The detection circuit detects the mutual capacitance between the first and second electrodes, which is the equivalent capacitance resulting from the combined effect of the horizontal and vertical capacitances. The conductive top layer, while serving as a reference electrode in mutual capacitance modulation, also provides electromagnetic shielding and electrostatic discharge. When pressure is applied, the elastic layer compresses, and the conductive top layer moves closer to the electrodes, increasing the vertical capacitance and correspondingly decreasing the mutual capacitance. The detection circuit detects the pressure applied by sensing the change in mutual capacitance. This invention has strong anti-interference capabilities and high reliability, making it suitable for high-reliability applications such as automotive, outdoor, industrial control, marine, and aviation applications.

Description

Technical Field

[0001] This invention relates to the field of pressure sensing technology, specifically to a capacitive pressure sensing device, which can be widely used in fields such as robot tactile sensing, smart wearable devices, industrial pressure measurement, medical and health monitoring, vehicle-mounted pressure sensing systems, outdoor environmental monitoring equipment, marine navigation equipment, avionics equipment, and pressure input interfaces for electronic equipment. Background Technology

[0002] Capacitive pressure sensors are widely used in the field of pressure sensing due to their advantages such as low power consumption, fast response speed, and relatively simple manufacturing process. Traditional capacitive pressure sensors typically employ a parallel-plate capacitor structure, measuring pressure by detecting the change in capacitance caused by the change in the distance between the two plates under pressure.

[0003] However, capacitive pressure sensors suffer from a significant technical problem in practical applications—susceptibility to external electromagnetic interference. The capacitive sensing principle makes them highly sensitive to changes in the external electric field. External electromagnetic radiation, radio frequency interference, nearby moving conductors, or time-varying electric field sources can all couple to the sensor's detection electrodes, causing signal shifts or increased noise. This problem is particularly pronounced in scenarios with complex electromagnetic environments, such as automotive, outdoor, industrial control, marine, and aviation applications, severely impacting the sensor's detection reliability and system stability.

[0004] Furthermore, capacitive pressure sensors also face the problems of electrostatic accumulation and electrostatic discharge damage. In dry or high-static-area environments, friction or induced charging can cause a large amount of static charge to accumulate on the insulating layer of the sensor's outer surface. Because the insulating layer is a high-resistivity material, the static charge cannot be discharged in time, forming a gradually increasing electrostatic field inside the insulating layer. When the electrostatic field strength exceeds the breakdown threshold, electrostatic discharge will occur. The instantaneous high voltage can directly break down the sensitive electrode inside the sensor or damage the signal processing circuit connected to it, leading to permanent sensor failure or significant performance degradation.

[0005] To address the aforementioned issues, existing technologies have proposed several capacitive pressure sensor solutions with shielded structures. These include placing a metal housing or metal shielding layer outside the sensor and grounding it, or employing double-shielded cable technology to suppress the effects of parasitic capacitance. For example, US20170350771A1 (UNEO Inc.) discloses a force sensor with a noise shielding layer. It uses coplanar electrodes arranged on the upper surface of a bottom substrate and a grounded noise shielding layer at the top, with a compressible recovery dielectric material in between. However, the top shielding layer in this document is solely used to eliminate noise signals generated by human touch sensing; its design purpose is clear and singular—the shielding layer is never defined as a reference electrode actively participating in capacitance modulation. Furthermore, this document does not disclose an equivalent model based on mutual capacitance detection or the specific working mechanism for reducing mutual capacitance under pressure.

[0006] Therefore, all the existing shielding solutions mentioned above have varying degrees of drawbacks. Placing a separate shielding shell or layer outside the sensor significantly increases the overall thickness and structural complexity of the sensor, hindering miniaturization and weight reduction. For applications requiring conformal fitting to curved surfaces or flexible mounting, it also reduces the sensor's flexibility and bending durability. Simultaneously, parasitic capacitance inevitably forms between the shielding layer and the sensing electrode. In compressible structures, this parasitic capacitance changes with pressure and cannot be eliminated through simple compensation, thus reducing the sensor's signal-to-noise ratio. When expanded into an array, the parasitic capacitance effect exacerbates crosstalk between elements, hindering the realization of high-resolution arrays. Furthermore, most existing shielding solutions require additional manufacturing processes, increasing process complexity and manufacturing costs. More critically, although the existing shielding layer is located outside the sensor, it does not have the function of actively discharging static charge. Static charge generated on the surface of the external insulating layer due to friction or induction can still accumulate and eventually trigger electrostatic discharge.

[0007] In summary, while existing capacitive pressure sensors achieve effective electromagnetic shielding, they inevitably suffer from problems such as increased parasitic capacitance, decreased signal-to-noise ratio, increased thickness, reduced flexibility, exacerbated array crosstalk, and manufacturing complexity. Furthermore, they cannot effectively address the issues of static electricity accumulation and electrostatic discharge damage. Therefore, there is an urgent need in this field for a novel pressure sensing device that can achieve effective electromagnetic shielding, actively discharge static charge to eliminate the risk of electrostatic discharge, avoid introducing significant parasitic capacitance side effects, and possess a simple structure that is easy to array and miniaturize. Summary of the Invention

[0008] The present invention aims to provide a pressure sensing device to solve the problems faced by existing capacitive pressure sensors in achieving electromagnetic shielding, such as complex structure, increased thickness, parasitic capacitance interference, decreased signal-to-noise ratio, difficulty in achieving high-density arraying, and inability to effectively prevent electrostatic accumulation and electrostatic discharge damage.

[0009] To achieve the above objectives, the present invention provides the following technical solution: A pressure sensing device, comprising: A circuit board having a first electrode and a second electrode that are coplanar and close to each other, with a horizontal capacitance between the first electrode and the second electrode. An insulating elastic layer covers the first electrode and the second electrode; A conductive top layer covers the elastic layer; the first electrode and the second electrode respectively form a vertical capacitance with the conductive top layer; and the conductive top layer is grounded or connected to a reference voltage; and A detection circuit, connected to the first electrode and the second electrode, is used to detect the mutual capacitance between the first electrode and the second electrode. The mutual capacitance corresponds to the equivalent capacitance actually detected by the detection circuit, and the value of the mutual capacitance is determined by the horizontal capacitance and the vertical capacitance. When the pressure sensing device is subjected to pressure, the elastic layer is compressed, which reduces the distance between the conductive top layer and the first electrode and the second electrode. The vertical capacitance increases, and the increased vertical capacitance causes the mutual capacitance detected by the detection circuit to decrease. The detection circuit detects the pressure by detecting the change in the mutual capacitance.

[0010] In this application, the first and second electrodes are coplanar and adjacent to each other, and there is generally no directly opposite region between them. When a voltage difference is applied between the first and second electrodes, electric field lines extend outward from the electrode edges, forming an edge electric field, thereby establishing a direct capacitive coupling between the first and second electrodes. This inherent physical capacitance is defined as the horizontal capacitance. The magnitude of the horizontal capacitance mainly depends on the adjacent spacing between the first and second electrodes, the adjacent side lengths of the electrode pattern, and the combined dielectric constant of the surrounding medium.

[0011] After the conductive top layer is applied over the elastic layer, it forms a first vertical capacitance and a second vertical capacitance with the first and second electrodes, respectively. The magnitude of the vertical capacitance depends on the overlap area between the conductive top layer and the corresponding electrode, the thickness of the elastic layer, and its dielectric constant. Since the conductive top layer is grounded or connected to a reference voltage, it constitutes a reference potential layer, which attracts and shunts the edge electric field between the first and second electrodes, weakening the direct electric field coupling between them.

[0012] In the circuit equivalent model, the mutual capacitance actually measured by the detection circuit is not simply the physical horizontal capacitance, but rather the equivalent capacitance resulting from the combined effect of the horizontal and vertical capacitances. To more clearly illustrate its physical mechanism, let the horizontal capacitance be C. H The vertical capacitance between the first electrode and the conductive top layer is C. V1 The vertical capacitance between the second electrode and the conductive top layer is C. V2 In the circuit equivalent model, the mutual capacitance C measured by the detection circuit... M It can be approximated as: C M ≈C H -C H 2 / (C H +C V1 +C V2 ) From the above equation, it can be seen that when pressure compresses the elastic layer and the conductive top layer approaches the electrode, C V1 and CV2 Increase, C M The corresponding capacitance decreases. This mathematical model clarifies the quantitative relationship between the two capacitance components and the detection results, providing a clear physical explanation for understanding the direction of signal change (decreasing rather than increasing) under pressure. When external pressure compresses and thins the elastic layer, the vertical capacitance increases, and the shunting effect of the conductive top layer on the edge electric field is enhanced, resulting in a decrease in the mutual capacitance measured by the detection circuit. The detection circuit infers the magnitude of the pressing pressure by detecting the change in this mutual capacitance.

[0013] It is important to note that the core function of the conductive top layer in this application is not shielding, but rather serving as a plate of a vertical capacitor, modulating mutual capacitance through changes in the distance between it and the coplanar electrodes. Shielding is a byproduct of grounding the conductive top layer, not its intended purpose. The top shielding layers in existing technologies (such as those disclosed in US20170350771A1) are designed solely to eliminate noise signals; they have never been defined as sensing elements or reference electrodes actively involved in capacitance modulation. Repositioning the "noise shielding layer" as a "reference layer for actively modulating mutual capacitance" represents a functional leap in technological understanding, and the resulting mutual capacitance modulation mechanism is not addressed in existing technologies.

[0014] For ease of description, the linewidths of the first electrode and the second electrode are defined as a1 and a2, respectively, and the adjacent spacing between them is b. In a preferred embodiment, the first electrode and the second electrode have the same linewidth, i.e., a1=a2=a; the electrode gap b is the distance between adjacent edges of the first electrode and the second electrode. The following parameter optimization description is based on the case where a1=a2=a, but those skilled in the art should understand that when a1≠a2, a can be taken as the average or smaller value of the two for reference design.

[0015] In the structure described in this application, the pressure sensitivity mainly depends on the rate of change of mutual capacitance measured by the detection circuit when the elastic layer is compressed. Based on the electric field distribution characteristics and the mechanical-electrical coupling mechanism, the preferred dimensional relationship between the electrode width a, the electrode gap b, and the elastic layer thickness c is as follows: (1) Relationship between elastic layer thickness c and electrode gap b The edge electric field generated by the coplanar electrodes is distributed in an arch shape above the electrode gap, and its effective depth is on the same order of magnitude as the electrode gap b. If the thickness c of the elastic layer is much greater than b, the edge electric field is significantly attenuated before reaching the conductive top layer, the shunting effect of the conductive top layer on the electric field is weak, and the sensitivity caused by pressure is reduced; if c is much smaller than b, most of the edge electric field lines are cut off by the conductive top layer, the initial mutual capacitance value is too low, and it is easy to enter the saturation region under pressure, resulting in poor linearity.

[0016] Preferably, the thickness c of the elastic layer and the electrode gap b satisfy the following relationship: 0.3b ≤ c ≤ 1.5b. Within this range, the conductive top layer is located precisely in the spatial region with a large edge electric field intensity, which can ensure a sufficient initial mutual capacitance signal value and enable the compression deformation to effectively modulate the electric field distribution, thereby obtaining high relative sensitivity.

[0017] (2) Relationship between electrode width a and electrode gap b The electrode width 'a' determines the absolute value reference of the horizontal capacitance. If 'a' is too small, the absolute value of the horizontal capacitance is too low, and the signal-to-noise ratio decreases; if 'a' is too large, the proportion of the edge electric field in the total electric field decreases, and the sensitivity of the mutual capacitance to local deformation at the electrode gap weakens.

[0018] Preferably, the electrode width 'a' and the electrode gap 'b' satisfy the following relationship: 1 ≤ a / b ≤ 5. Within this range, the absolute value of the horizontal capacitance remains at a detectable level, and the proportion of the edge electric field remains at a high level, which is beneficial to improving the sensitivity of pressure detection.

[0019] (3) The dielectric constant ε of the elastic layer r Co-selection with thickness c The dielectric constant ε of the elastic layer r The dielectric constant directly affects the size of the vertical capacitance, which in turn affects the shunting capability of the conductive top layer for the edge electric field. A higher dielectric constant results in a larger vertical capacitance for the same thickness and overlapping area, leading to a stronger shunting capability and greater sensitivity of mutual capacitance to thickness variations. However, an excessively high dielectric constant can cause an excessively large initial vertical capacitance, resulting in most edge electric field lines being prematurely drawn to the conductive top layer. This leads to an excessively small initial mutual capacitance and easy saturation of the pressure response, ultimately reducing the effective detection range.

[0020] Therefore, the selection of the dielectric constant needs to be optimized in conjunction with the elastic layer thickness c: when c is close to 1.5b, the relative dielectric constant ε should be selected. r A material with a relative permittivity ≥5 is used to compensate for the reduced shunting effect due to increased thickness; when c is close to 0.3b, a relative permittivity ε should be selected. r The elastic material is of a relative permittivity of 2 to 4 to avoid premature saturation. Preferably, the relative permittivity ε of the elastic layer is... r The value is 2 to 10, and more preferably 3 to 6.

[0021] In a preferred embodiment of the present invention, the first electrode and the second electrode may employ an interdigitated electrode structure or a meandering / wound electrode structure to increase the effective edge length between them, thereby improving the sensitivity of pressure sensing. Based on the aforementioned parameter optimization relationship, the adjacent spacing between the first electrode and the second electrode is the aforementioned electrode gap b, and the linewidth of the electrode itself is the aforementioned electrode width a. The selection of the linewidth a and gap b of the above structure should be coordinated with the elastic layer thickness c, following the aforementioned parameter optimization relationship.

[0022] In the interdigitated electrode structure, the first electrode includes a first common lead and a plurality of first finger-shaped sub-electrodes extending from the first common lead toward the second electrode; the second electrode includes a second common lead and a plurality of second finger-shaped sub-electrodes extending from the second common lead toward the first electrode. The first and second finger-shaped sub-electrodes are alternately arranged and spaced apart from each other along the electrode gap direction, forming an interdigitated pair. The gap between each first finger-shaped sub-electrode and its adjacent second finger-shaped sub-electrode constitutes the effective working area of ​​the horizontal capacitance. Since the strength of the horizontal capacitance is positively correlated with the total length of the edges of adjacent electrodes, with the interdigitated structure, the total effective edge length increases significantly under the same electrode layout area, the absolute value of the horizontal capacitance increases, and the relative sensitivity of the mutual capacitance to changes in the thickness of the elastic layer is correspondingly improved.

[0023] In the meandering or coiled electrode structure, the first electrode and the second electrode are each a continuous linear electrode, extending within the plane of the circuit board in a meandering or coiled manner. In the meandering electrode structure, the first and second electrodes are arranged parallel and adjacent to each other in a serpentine or U-shaped zigzag pattern, with a constant spacing between them. Adjacent segments of each zigzag line form an effective edge for coupling capacitance. In the coiled electrode structure, the first and second electrodes are spirally coiled together, maintaining a constant spacing along the coiling path, forming a continuous effective edge for capacitive coupling along the entire coiling path. Both the meandering and coiled electrode structures increase the absolute value of the horizontal capacitance by increasing the total length of the linear electrodes, thereby improving the sensitivity of pressure detection.

[0024] In a preferred embodiment of the present invention, the pressure sensing device may employ an array structure to achieve multi-point pressure detection.

[0025] Specifically, the circuit board has multiple driving lines extending along a first direction and multiple sensing lines extending along a second direction. The first and second directions intersect (preferably perpendicularly), causing the driving lines and sensing lines to form multiple intersection points in the projection. At each intersection point, the driving line connects to a first electrode, and the sensing line connects to a second electrode. The first and second electrodes are coplanar and close to each other, and there is a horizontal capacitance between them. An elastic layer covers the first and second electrodes at each intersection point, and a conductive top layer covers the elastic layer, such that each first and second electrode forms a vertical capacitance with the conductive top layer. The first and second electrodes at each intersection point, together with the elastic and conductive top layers at that point, constitute an independent pressure sensing unit.

[0026] When external pressure is applied to a location on the conductive top layer, the elastic layer in one or more pressure sensing units corresponding to that location undergoes compression deformation, causing a change in the mutual capacitance of the corresponding sensing units. By setting up a detection circuit (or signal processing control unit) electrically connected to each drive line and each sensing line, excitation signals are sequentially applied to each drive line in a time-division scanning manner. Coupled signals are read from all sensing lines when each drive line is excited, thus obtaining the mutual capacitance data matrix corresponding to each intersection point. By comparing this matrix with a reference matrix under no-pressure conditions, all intersection points where mutual capacitance changes occur and their changes can be identified, thereby simultaneously detecting the location and pressure magnitude of multiple pressure application points, achieving multi-point pressure distribution detection. The scanning frame rate of the detection circuit is preferably not less than 50Hz to achieve real-time detection.

[0027] In a preferred embodiment of the present invention, in the array structure, each driving line and sensing line, and the first electrode and second electrode connected thereto, can adopt the following substrate and electrode manufacturing scheme.

[0028] In one basic implementation, the circuit board is a rigid PCB (e.g., FR-4 grade copper-clad laminate) or a flexible FPC (which ultimately needs to be attached to a rigid substrate). The drive lines, sensing lines, first electrode, and second electrode are formed using conventional PCB etching processes. This solution is technologically mature, cost-effective, and suitable for general pressure distribution detection applications.

[0029] In a preferred embodiment, to further improve the detection consistency and pressure sensitivity of the sensing array, the circuit board is made of a glass substrate. The driving lines, sensing lines, first electrode, and second electrode are formed into a metal thin film on the surface of the glass substrate by magnetron sputtering or vapor deposition, and then the metal thin film is patterned by photolithography and etching. Compared with PCB etching, the glass substrate has extremely high surface flatness. Combined with photolithography, more precise electrode patterns and more uniform electrode surfaces can be obtained, thereby ensuring a high degree of coplanarity between the first and second electrodes at each intersection point. This makes the initial mutual capacitance values ​​of each sensing unit tend to be consistent under no-pressure conditions, which is beneficial for simplifying reference calibration and subsequent signal processing. At the same time, the high flatness of the glass substrate, combined with the high-precision photolithographic electrode pattern, provides a flat and uniform substrate for the coating of the elastic layer, which is beneficial for ensuring the thickness uniformity of the elastic layer in each intersection point area. Furthermore, the glass substrate may be selected from soda-lime glass, borosilicate glass or alkali-free glass, with a thickness of 0.1 mm to 3 mm; the metal thin film is made of copper, aluminum, molybdenum, chromium, titanium or a combination of the above metals, with a thickness of 50 nm to 500 nm.

[0030] The elastic layer should be made of a compressible material with good elasticity and electrical insulation properties, capable of reversible compressive deformation under pressure and returning to its initial thickness after the pressure is removed. It is particularly important to emphasize that the elastic layer of this invention is an insulating elastic material, its function being to provide reversible compressive deformation, rather than a piezoresistive or semiconductor material.

[0031] In one basic embodiment, the elastic layer may be made of an elastic polymer material, such as polydimethylsiloxane, polyurethane, silicone rubber, thermoplastic polyurethane elastomer, natural rubber, styrene-butadiene rubber, styrene-butadiene-styrene block copolymer, hydrogenated styrene-butadiene block copolymer, etc. The elastic layer may also be a foam of the above materials, such as polyurethane foam, silicone rubber foam, etc.

[0032] In a preferred embodiment, the elastic layer is made of polyurethane elastomer or silicone rubber. Both materials have low compression set, meaning they can recover to their initial thickness well after repeated compression, which helps ensure the detection stability and repeatability of the device during long-term repeated use. The Shore A hardness of the elastic layer is preferably between 20 and 60.

[0033] In a preferred embodiment to further improve sensitivity, the elastic layer can be made of a porous elastomer material, such as polyurethane foam or porous PDMS. The porous structure gives the elastic layer a lower compressive modulus and greater compressive deformation capacity, allowing for a larger thickness change under the same pressure. Simultaneously, during compression, the porous structure is compacted, increasing the effective dielectric constant of the material and further amplifying the change in vertical capacitance, thereby effectively improving the sensitivity of pressure detection. The porosity of the porous elastomer is preferably 30% to 95%, and the compressive modulus is preferably 3 kPa to 500 kPa.

[0034] In a preferred embodiment to further improve sensitivity, the elastic layer may have open, hollowed-out, or thinned regions at specific locations to enhance its local deformation capability under stress, thereby further improving the sensitivity of pressure detection. Specifically, at positions corresponding to the first and second electrodes, the elastic layer may be partially or completely left open (i.e., forming cavities), hollowed out (i.e., forming through-holes or trenches), or thinned (i.e., forming thickness-reduced regions). Since this region is where the electric field of the vertical capacitance is concentrated, leaving open, hollowing out, or thinning the elastic layer in this region can effectively reduce the structural stiffness at this location, allowing the conductive top layer to generate greater local deformation in this region when subjected to pressure, thereby increasing the amplitude of the change in vertical capacitance and the amount of change in mutual capacitance, significantly improving the sensitivity of pressure detection. Here, it is necessary to ensure that the conductive top layer does not short-circuit with the first or second electrode when deformation occurs. To this end, an insulating protective layer can be provided on the upper surface of the first and second electrodes. This layer can be coated with a photosensitive resin (such as polyimide, epoxy resin, etc.) or an insulating material such as silicon dioxide with a thickness of micrometers. This insulating protective layer only covers the surface area of ​​the electrodes, does not affect the compressive deformation of the elastic layer, and effectively isolates the conductive top layer from the electrodes. The thickness of the insulating protective layer is preferably less than 2 μm. Furthermore, the size and shape of the open, hollowed-out, or thinned areas can be designed according to the size of the electrodes and the required sensitivity. Preferably, the width of the open or hollowed-out areas does not exceed the electrode width 'a', to maintain normal contact and support between the conductive top layer and the elastic layer when not under pressure. This design, by locally reducing the structural stiffness of the elastic layer, concentrates the deformation caused by pressure in the area with the strongest edge electric field, effectively improving sensitivity without changing the compressive modulus of the material itself.

[0035] From a mechanical performance perspective, the elastic layer preferably possesses the following characteristics: a compression set rate of no more than 5% to reduce zero-point drift after long-term use; a hysteresis loop area as small as possible in the force-deformation curve to reduce hysteresis errors in pressure testing; and relatively linear compression deformation characteristics within the target pressure range to simplify the calibration of the pressure-capacitance mapping relationship. These mechanical performance parameters can be controlled through material selection, crosslinking degree adjustment, filler addition, or foaming process.

[0036] In the array structure, to ensure the consistency of each sensing unit, the thickness deviation of the elastic layer at each intersection area is preferably controlled within ±10%, and more preferably within ±5%.

[0037] In summary, the selection of materials for the elastic layer must consider compressive strength, resilience, dielectric constant, and process adaptability. Polyurethane foam, with its low compressive modulus and good resilience, is suitable for applications requiring high sensitivity; silicone rubber and PDMS offer excellent resilience and chemical stability, making them suitable for applications requiring long-term stability and repeatability; porous elastomer materials can significantly improve sensitivity by reducing compressive modulus and increasing deformation capacity, making them suitable for applications requiring high-sensitivity detection. Specific materials and morphologies can be selected based on the target pressure detection range, sensitivity requirements, and manufacturing process conditions.

[0038] The conductive top layer is a conductive layer covering the elastic layer, which, together with the first electrode and the second electrode, forms a vertical capacitor. The conductive top layer must possess both good conductivity and appropriate flexibility to ensure it can adapt to the compressive deformation of the elastic layer and effectively transmit external pressure to the elastic layer. Preferably, the conductive top layer is a continuous conductive layer, rather than a mesh or grid structure, to ensure the formation of a uniform and stable vertical capacitor with the electrodes.

[0039] In one basic embodiment, the conductive top layer is a flexible thin film with a conductive layer deposited on its surface, such as a polyethylene terephthalate (PET) film with a metal layer or an indium tin oxide (ITO) layer. This solution has mature technology, low cost, and is suitable for general applications. The metal layer can be selected from copper, aluminum, nickel, silver, or alloys of the above metals, and the coating thickness is preferably 50 nm to 500 nm.

[0040] In a preferred embodiment, the conductive top layer is made of metal cloth. The metal cloth is woven from conductive fibers (such as metal fibers, metal-plated organic fibers, or conductive yarns), and has better flexibility and bending resistance than coated flexible films. It can adhere more tightly to the surface of the elastic layer and is less prone to wrinkling or delamination during repeated pressure, which helps ensure the stability of the vertical capacitance and the long-term reliability of the device. The sheet resistance of the metal cloth is preferably no greater than 1 Ω / □.

[0041] In another preferred embodiment, the conductive top layer is a conductive rubber layer. The conductive rubber layer can be made by filling an elastomer matrix (e.g., silicone rubber, polyurethane, or PDMS) with conductive fillers (e.g., carbon black, carbon nanotubes, graphene, or metal particles) and directly coating or curing it onto the upper surface of the elastic layer. Compared to independently molded conductive films or metal cloths, the conductive rubber layer is integrated with the elastic layer, avoiding problems such as poor interlayer adhesion or relative slippage. Simultaneously, the conductive rubber layer itself has good elasticity and deformation capacity, enabling it to compress and rebound synchronously with the elastic layer, ensuring that the conductive top layer remains in close contact with the elastic layer during pressure application, effectively improving the structural stability of the device and the repeatability of pressure detection. The volume resistivity of the conductive rubber layer is preferably not greater than 10 Ω·cm, and the Shore A hardness is preferably between 30 and 70.

[0042] In all the above solutions, the conductive top layer should be grounded or connected to a reference voltage to form the reference potential layer. Preferably, the conductive top layer is grounded or connected to the reference voltage in the following way: the conductive top layer can be electrically connected to the ground terminal or reference voltage terminal on the circuit board through conductive jumpers, conductive silver paste, conductive tape, or flexible cables disposed on the edge of the circuit board, thereby forming a common ground or common potential connection between the conductive top layer and the circuit board. This connection method is simple in structure, easy to implement, and does not occupy the effective area of ​​the sensing area, which is beneficial to maintaining the integrity and consistency of the sensing area. The specific material can be selected according to the required flexibility, conductivity, thickness, and manufacturing cost. For scenarios with high requirements for the overall thickness and structural simplicity of the device, a conductive rubber layer solution is preferred; for applications that need to withstand repeated bending or curved surface bonding, a metal cloth solution is preferred; for conventional planar detection applications, a flexible film with a conductive layer can meet the requirements.

[0043] Compared with the prior art, the present invention has the following outstanding advantages: 1. Excellent electromagnetic shielding performance and strong anti-interference ability. In this invention, a conductive top layer covers the elastic layer and is grounded or connected to a reference voltage, forming a complete reference potential layer. This conductive top layer, together with the circuit board (especially when the board has a ground layer), forms a closed or substantially closed electromagnetic shielding structure, completely enclosing the first electrode, the second electrode, and the electric field coupling region between them within the shielding structure. Because the conductive top layer is grounded or connected to the reference voltage, it attracts and shunts the edge electric field between the first and second electrodes, while also forming an effective barrier against external electromagnetic interference signals, making it difficult for external electromagnetic fields to penetrate the conductive layer and couple to the internal circuit. Furthermore, the conductive top layer can be a continuous, full-surface coverage (such as a metal cloth or conductive rubber layer), further physically forming a continuous, closed shielding cavity, ensuring the internal circuit is completely shielded.

[0044] 2. High reliability, suitable for high-reliability applications. On the one hand, this invention possesses excellent electromagnetic shielding performance, making the detection signal less susceptible to adverse factors such as electromagnetic radiation and radio frequency interference in the external environment, resulting in a high signal-to-noise ratio and stability. On the other hand, the grounded conductive top layer forms a low-impedance electrostatic discharge path. When static charges generated by friction or induction in the external environment accumulate on the device surface, they can be quickly conducted away through the grounded conductive top layer, preventing the accumulation of high-voltage electrostatic fields within the device's internal or surface insulation layers, thus completely eliminating the risk of electrostatic accumulation and electrostatic discharge damage. Furthermore, the conductive top layer, covering the outermost part of the device, also provides physical protection against dust, moisture, and scratches. Therefore, this invention is particularly suitable for applications with high reliability requirements, such as automotive, outdoor, industrial control, marine, and aviation applications. In these scenarios, it can stably and accurately complete pressure detection tasks over a long period, without being prone to misjudgment, performance degradation, or permanent failure due to external electromagnetic interference or electrostatic discharge.

[0045] 3. High sensitivity and excellent detection performance. This invention forms a horizontal capacitor through a first and second electrode arranged in a coplanar manner, and a vertical capacitor through a conductive top layer grounded or connected to a reference voltage. When pressure is applied, the elastic layer is compressed, bringing the conductive top layer closer to the electrode, increasing the vertical capacitance. This enhances the shunting effect of the vertical capacitance on the horizontal electric field, resulting in a decrease in the mutual capacitance measured by the detection circuit. By rationally designing the dimensional relationship between the electrode width a, the electrode gap b, and the elastic layer thickness c (preferably 0.3b≤c≤1.5b, 1≤a / b≤5), the conductive top layer is positioned precisely in the spatial region with the greatest edge electric field strength, further improving the detection sensitivity.

[0046] 4. Simple structure, easy to manufacture and integrate. This invention only requires fabricating a first and second electrode arranged coplanarly on a circuit board, and then sequentially covering them with an elastic layer and a conductive top layer to form a complete pressure sensing unit. It eliminates the need for complex microstructure fabrication processes, is highly compatible with mature PCB, FPC, and semiconductor photolithography processes, and boasts low manufacturing costs and high yields. By employing an optimized scheme using a glass substrate in conjunction with the photolithography process, electrode precision and array consistency can be further improved.

[0047] 5. Easy to implement high-density arrayed multi-point detection This invention utilizes a cross-point array formed by multiple driving lines and multiple sensing lines on a circuit board, with each cross-point constituting an independent pressure sensing unit. By sequentially driving each driving line and reading all sensing lines in parallel using a time-division scanning method, pressure information from all points in the entire array can be acquired simultaneously. This eliminates the need for independent wiring for each detection point, significantly simplifying the array's hardware complexity and facilitating high-density integration and miniaturization.

[0048] 6. Electrode reuse design further improves performance. By designing the first and second electrodes as interdigitated electrode structures or meandering / wound electrode structures, the effective edge length of the electrodes can be significantly increased without changing the density of the sensing point array, thereby increasing the absolute value of the horizontal capacitance and improving the relative sensitivity of the mutual capacitance to changes in the thickness of the elastic layer. Attached Figure Description

[0049] Figure 1 This is a schematic diagram of the overall structure of a pressure sensing device according to the present invention; Figure 2 This is a schematic diagram of the electrodes of a single sensing unit of a pressure sensing device according to the present invention. Figure 3 This is a cross-sectional schematic diagram of a pressure sensing device according to the present invention; Figure 4 This is a schematic diagram of a pressure sensing device of the present invention, wherein the electrodes adopt a straight electrode structure; Figure 5 This is a schematic diagram of a pressure sensing device of the present invention, wherein the electrodes adopt a detour electrode structure; Figure 6 This is a schematic diagram of a pressure sensing device of the present invention, wherein the electrodes adopt a wound electrode structure; Figure 7 This is a cross-sectional schematic diagram of a pressure sensing device of the present invention, wherein the elastic layer is left open, hollowed out, or thinned. Detailed Implementation

[0050] The technical solution of the present invention will now be described in detail with reference to the accompanying drawings and preferred embodiments. The following embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Example

[0051] This embodiment provides an array-type multi-point pressure sensing device to realize the detection of multi-point pressure distribution on a two-dimensional plane.

[0052] like Figure 1 , Figure 2As shown, the pressure sensing device 100 mainly includes: a circuit board 110, multiple drive lines 121 and multiple sensing lines 122 disposed on the circuit board 110, an elastic layer 130 covering the drive lines 121 and sensing lines 122, a conductive top layer 140 covering the elastic layer 130, and a signal processing control unit 150 electrically connected to each drive line 121 and each sensing line 122.

[0053] The drive lines 121 extend along a first direction (e.g., the Y-axis direction), totaling M lines; the sensing lines 122 extend along a second direction (e.g., the X-axis direction), totaling N lines. The first direction and the second direction intersect perpendicularly (the intersection point is equipped with a jumper structure 123), such that the drive lines 121 and the sensing lines 122 form an M-row × N-column intersection array in the vertical projection direction. Each intersection point constitutes an independent pressure sensing unit 101, and the entire array contains M × N sensing units 101, enabling simultaneous detection of multi-point pressure distribution. The pitch between adjacent drive lines 121 and the pitch between adjacent sensing lines 122 jointly determine the spatial density of the sensing points. In this embodiment, the pitch is preferably 1mm to 10mm, which can be set according to the required spatial resolution.

[0054] like Figure 2 , Figure 3 As shown, at each intersection, the local structure is as follows: The circuit board 110 is made of glass substrate 111. The glass substrate 111, as a bearing substrate, has extremely high surface flatness and can be selected from soda-lime glass, borosilicate glass or alkali-free glass, with a thickness preferably from 0.3 mm to 1.1 mm.

[0055] On the surface of the glass substrate 111, a metal thin film (e.g., a copper / molybdenum stack, preferably with a total thickness of 200 nm to 300 nm) is formed by magnetron sputtering or vapor deposition. The metal thin film is then patterned using photolithography and etching processes to form a coplanar and closely spaced first electrode 1211 and a second electrode 1221. At each intersection, the driving line 121 connects to a first electrode 1211, and the sensing line 122 connects to a second electrode 1221. The first electrode 1211 and the second electrode 1221 are coplanar and closely spaced, and a horizontal capacitance C exists between them. HThe first electrode 1211 and the second electrode 1221 preferably employ an interdigitated electrode structure to increase the effective edge length between them, thereby improving the absolute value of the horizontal capacitance and the sensitivity to pressure changes. In the interdigitated electrode structure, the first electrode 1211 includes a first common lead 1212 and a plurality of first finger-shaped sub-electrodes 1213 extending from the first common lead 1212 toward the second electrode 1221; the second electrode 1221 includes a second common lead 1222 and a plurality of second finger-shaped sub-electrodes 1223 extending from the second common lead 1222 toward the first electrode 1211; the first finger-shaped sub-electrodes 1213 and the second finger-shaped sub-electrodes 1223 are alternately arranged and spaced apart from each other along the electrode gap direction, forming an interdigitated pair. The electrode linewidth a (a1, a2) and the electrode gap b are set according to the manufacturing process resolution and the required sensitivity, preferably the linewidth a is 5μm to 100μm and the gap b is 5μm to 100μm. Furthermore, the ratio of the line width a to the gap b satisfies 1≤a / b≤5, so that the absolute value of the horizontal capacitance is maintained at a detectable level, while ensuring that the proportion of the edge electric field remains at a high level.

[0056] The elastic layer 130 covers the first electrode 1211 and the second electrode 1221. In this embodiment, the elastic layer 130 is preferably made of polyurethane elastomer or silicone rubber material, with a Shore A hardness preferably between 20 and 60, exhibiting a low compression set and good resilience. The thickness c of the elastic layer 130 is set according to the electrode gap b, preferably satisfying 0.3b ≤ c ≤ 1.5b, so that the conductive top layer 140 is located precisely in the spatial region with a high edge electric field intensity, thereby obtaining high pressure sensitivity.

[0057] The conductive top layer 140 covers the elastic layer 130. In this embodiment, the conductive top layer 140 is preferably a conductive rubber layer 141. The conductive rubber layer 141 is made by filling a conductive filler (e.g., carbon black, carbon nanotubes, or graphene) into an elastomer matrix (e.g., silicone rubber or polyurethane) and directly coating or curing it onto the upper surface of the elastic layer 130. The volume resistivity of the conductive rubber layer 141 is preferably not greater than 10 Ω·cm, and the Shore A hardness is preferably 30 to 70. The conductive rubber layer 141 and the elastic layer 130 are integrated into a single structure, avoiding problems such as poor interlayer adhesion or relative slippage. At the same time, the conductive rubber layer 141 itself has good elasticity and deformation capacity, and can be compressed and rebounded synchronously with the elastic layer 130, ensuring that the conductive top layer 140 always maintains close contact with the elastic layer 130 during the compression process. The first electrode 1211 and the second electrode 1221 respectively form a vertical capacitor with the conductive top layer 140. The conductive top layer 140 is electrically connected to the ground terminal or reference voltage terminal of the signal processing control unit 150 via conductive jumpers, conductive silver paste, or flexible cables disposed at the edge of the glass substrate 111, thereby forming a common ground or common potential connection and constituting a reference potential layer. The conductive top layer 140 is a continuous conductive layer, rather than a mesh or grid structure, to ensure the formation of a uniform and stable vertical capacitance with the electrodes.

[0058] In this embodiment, the pressure detection principle at each intersection is as follows: The first electrode 1211 and the second electrode 1221 are coplanar and close to each other, with no directly opposite region between them. When a voltage difference is applied between the first and second electrodes, electric field lines extend outward from the electrode edges, forming an edge electric field. This establishes a direct capacitive coupling between the first electrode 1211 and the second electrode 1221, and this inherent physical capacitance is defined as the horizontal capacitance C. H The conductive top layer 140 covers the elastic layer 130 and forms vertical capacitances C with the first electrode 1211 and the second electrode 1221, respectively. V1 and C V2 Since the conductive top layer 140 is grounded or connected to the reference voltage, the conductive top layer 140 constitutes a reference potential layer, which attracts and shunts the edge electric field between the first electrode 1211 and the second electrode 1221, weakening the direct electric field coupling between the two.

[0059] In the circuit equivalent model, the mutual capacitance actually measured by the detection circuit (i.e., the signal processing control unit 150) is not simply the physical horizontal capacitance, but rather the equivalent capacitance resulting from the combined effect of the horizontal and vertical capacitances. The mutual capacitance C measured by the detection circuit... M It can be approximated as: C M ≈CH -C H 2 / (C H +C V1 +C V2 ) From the above equation, it can be seen that when pressure compresses the elastic layer and the conductive top layer approaches the electrode, C V1 and C V2 Increase, C M The corresponding decrease occurs when external pressure is applied to a location on the conductive top layer 140. The elastic layer 130 in one or more pressure sensing units 101 corresponding to that location undergoes compressive deformation, reducing the distance between the conductive top layer 140 and the first electrode 1211 and the second electrode 1221, thus increasing the vertical capacitance. This increased vertical capacitance enhances the attraction and shunting effect on the edge electric field, leading to a decrease in the mutual capacitance measured by the signal processing control unit 150.

[0060] The signal processing control unit 150 employs a time-division scanning method for full-array detection: AC excitation signals are sequentially applied to each drive line 121 in a certain order (e.g., line-by-line scanning), and while each drive line 121 is energized, the coupling signals on all sensing lines 122 are simultaneously and in parallel acquired to obtain an M×N real-time capacitance data matrix. This matrix is ​​compared with a reference matrix under no-pressure conditions to obtain a full-plane capacitance change distribution map, thus identifying all intersections where mutual capacitance changes occur and their magnitudes. For each intersection where capacitance changes, the corresponding pressure value is calculated based on its capacitance change using a pre-stored calibration curve; for multiple intersections where changes occur simultaneously, the pressure value and coordinate information of each point are output synchronously, thereby achieving simultaneous detection of multi-point pressure distribution. To ensure the smoothness of real-time detection, the scanning frame rate of the signal processing control unit 150 is preferably not less than 50Hz.

[0061] This embodiment achieves the following beneficial effects through the above structure: First, the grounded conductive rubber layer 141, together with the glass substrate 111, forms a basically closed electromagnetic shielding structure, completely enclosing the first electrode 1211, the second electrode 1221, and the electric field coupling region between them within the shielding structure. External electromagnetic interference signals have difficulty penetrating the conductive layer and coupling to the internal circuit, effectively improving the sensor's anti-interference capability. Second, the grounded conductive rubber layer 141 constitutes a low-impedance electrostatic discharge path. Static charges generated by friction or induction in the external environment can be quickly conducted away through this conductive layer, preventing the accumulation of high-voltage electrostatic fields inside the device and completely eliminating the risk of electrostatic discharge damage. Third, by rationally designing the relationship between the electrode gap b and the elastic layer thickness c (0.3b≤c≤1.5b) and the relationship between the electrode width a and the gap b (1≤a / b≤5), the conductive top layer 140 is positioned precisely in the spatial region with the greatest edge electric field strength. Combined with the significant increase in effective edge length due to the interdigitated electrode structure, high pressure detection sensitivity can be achieved. Fourth, the use of a glass substrate 111 combined with photolithography ensures high electrode pattern precision and good coplanarity, and the elastic layer 130 is uniformly coated, effectively guaranteeing the consistency of each sensing unit 101. Fifth, the array structure combined with a time-division scanning detection method eliminates the need for independent wiring for each detection point, significantly simplifying hardware complexity and facilitating high-density integration and miniaturization. Therefore, this embodiment is particularly suitable for high-reliability applications such as automotive, outdoor, industrial control, marine, and aviation.

[0062] The above embodiments are merely preferred embodiments of the present invention. Those skilled in the art should understand that, without departing from the core concept of the present invention, substitutions or modifications can be made to the following aspects: Regarding the substrate material, in addition to the glass substrate 111, the circuit substrate 110 can also be a rigid PCB (e.g., FR-4 grade copper-clad laminate) or a flexible PCB (e.g., polyimide or polyester film). The rigid PCB solution has mature technology and low cost, and is suitable for general industrial applications; the flexible PCB solution has good bending performance and is suitable for application scenarios that require bonding to curved surfaces or wearable devices.

[0063] like Figure 4 , Figure 5 , Figure 6 As shown, in terms of electrode structure, in addition to the interdigitated electrode structure, the first electrode 1211 and the second electrode 1221 can also adopt a straight electrode structure. Figure 4 ), circuitous electrode structure ( Figure 5 ) or wound electrode structure ( Figure 6Straight electrode structures are the simplest to manufacture and are suitable for scenarios where sensitivity requirements are not high. Detour and coiled electrode structures increase the absolute value of horizontal capacitance by increasing the total length of continuous linear electrodes, and there are no branch endpoints of interdigitated structures, which helps to reduce the resistance and parasitic effects of the electrodes themselves. They are suitable for scenarios that require longer trace lengths and have high requirements for resistance consistency.

[0064] Regarding the conductive top layer material, in addition to the conductive rubber layer 141, the conductive top layer 140 can also be made of metal cloth or a flexible film with a conductive layer deposited on its surface (e.g., a PET film with a metal or ITO layer). Metal cloth, woven from conductive fibers, offers better flexibility and bending resistance, making it suitable for applications requiring repeated bending or curved surface bonding. Flexible films with conductive layers have mature technology and lower costs, making them suitable for conventional planar inspection applications. Regardless of the material used, the conductive top layer 140 is preferably a continuously covering conductive layer, rather than a mesh or grid structure, to ensure a uniform and stable vertical capacitance with the electrodes.

[0065] Regarding the morphology of the elastic layer, in addition to a solid elastomer layer, the elastic layer 130 can also be made of porous elastomer materials (such as polyurethane foam, porous PDMS, etc.), which have a lower compressive modulus and a greater compressive deformation capacity, which can further improve the sensitivity of pressure detection and is suitable for application scenarios that require higher sensitivity.

[0066] like Figure 7 As shown, as an alternative design, the elastic layer 130 can have open, hollowed-out, or thinned areas 131 at specific locations to further enhance its local deformation capability under stress. Specifically, the elastic layer 130 can be partially or completely open, hollowed out, or thinned at positions corresponding to the first electrode 1211 and the second electrode 1221 to reduce the structural stiffness at those locations, allowing the conductive top layer 140 to generate greater local deformation in those areas when subjected to pressure, thereby improving pressure detection sensitivity. Here, it is necessary to ensure that the conductive top layer 140 does not short-circuit with the first electrode 1211 or the second electrode 1221 when deformed. To this end, an insulating protective layer 123 can be provided on the upper surface of the first electrode 1211 and the second electrode 1221, such as coating with a micron-thickness photosensitive resin or silicon dioxide, etc. This insulating protective layer 123 only covers the electrode surface area, does not affect the compressive deformation of the elastic layer 130, and effectively isolates the electrical contact between the conductive top layer 140 and the electrodes. The thickness of the insulating protective layer 123 is preferably less than 2 μm. This design, by locally reducing the structural stiffness of the elastic layer 130, concentrates the deformation caused by pressure in the region with the strongest edge electric field, effectively improving sensitivity without changing the compressive modulus of the material itself.

[0067] All of the above alternatives can be flexibly selected and combined according to specific application requirements, manufacturing process conditions and cost budgets, and all fall within the protection scope of this invention.

Claims

1. A pressure sensing device, characterized in that, include: A circuit board having a first electrode and a second electrode that are coplanar and close to each other, with a horizontal capacitance between the first electrode and the second electrode. An insulating elastic layer covers the first electrode and the second electrode; A conductive top layer covers the elastic layer, and the first electrode and the second electrode respectively form a vertical capacitance with the conductive top layer, and the conductive top layer is grounded or connected to a reference voltage; as well as A detection circuit, connected to the first electrode and the second electrode, is used to detect the mutual capacitance between the first electrode and the second electrode. The mutual capacitance corresponds to the equivalent capacitance actually detected by the detection circuit, and the value of the mutual capacitance is determined by the horizontal capacitance and the vertical capacitance. When the pressure sensing device is subjected to pressure, the elastic layer is compressed, which reduces the distance between the conductive top layer and the first electrode and the second electrode. The vertical capacitance increases, and the increased vertical capacitance causes the mutual capacitance detected by the detection circuit to decrease. The detection circuit detects the pressure by detecting the change in the mutual capacitance.

2. The pressure sensing device according to claim 1, characterized in that, The linewidth of the first electrode and the second electrode is a, the gap between them is b, and the thickness of the elastic layer is c, satisfying: 0.3b≤c≤1.5b.

3. The pressure sensing device according to claim 2, characterized in that, The line width a and the gap b satisfy the condition: 1≤a / b≤5.

4. The pressure sensing device according to claim 2, characterized in that, The relative permittivity of the elastic layer is 2 to 10.

5. The pressure sensing device according to claim 1, characterized in that, The elastic layer is made of an elastic polymer material selected from one or more of polydimethylsiloxane, polyurethane, silicone rubber, thermoplastic polyurethane elastomer, natural rubber, styrene-butadiene rubber, styrene-butadiene-styrene block copolymer, and hydrogenated styrene-butadiene block copolymer; or the elastic layer is a foam of the above materials.

6. The pressure sensing device according to claim 1, characterized in that, The first electrode and the second electrode adopt an interdigitated electrode structure. The first electrode includes a first common lead and a plurality of first finger-shaped sub-electrodes extending from the first common lead toward the second electrode. The second electrode includes a second common lead and a plurality of second finger-shaped sub-electrodes extending from the second common lead toward the first electrode. The first finger-shaped sub-electrodes and the second finger-shaped sub-electrodes are alternately arranged along the electrode gap direction and spaced apart from each other.

7. The pressure sensing device according to claim 1, characterized in that, The first electrode and the second electrode adopt a meandering electrode structure or a wound electrode structure. Each of the first electrode and the second electrode is a continuous linear electrode. They extend in the plane of the circuit board in a meandering or wound manner, and the distance between them remains constant.

8. The pressure sensing device according to claim 1, characterized in that, The circuit board is a glass substrate. The first electrode and the second electrode form a metal thin film on the surface of the glass substrate by magnetron sputtering or vapor deposition, and then the metal thin film is patterned by photolithography and etching.

9. The pressure sensing device according to claim 1, characterized in that, The first electrode and the second electrode are formed on a rigid PCB or a flexible PCB by a PCB etching process.

10. The pressure sensing device according to claim 1, characterized in that, The conductive top layer is a conductive rubber layer, which is coated or cured on the upper surface of the elastic layer and fused with the elastic layer to form an integral structure.

11. The pressure sensing device according to claim 1, characterized in that, The conductive top layer is a metal cloth, which is woven from conductive fibers.

12. The pressure sensing device according to claim 1, characterized in that, The conductive top layer is a flexible thin film with a conductive layer deposited on its surface.

13. The pressure sensing device according to claim 1, characterized in that, The conductive top layer is a continuously covered conductive layer.

14. The pressure sensing device according to claim 1, characterized in that, The elastic layer is a porous elastomer material with a porosity of 30% to 95% and a compressive modulus of 3 kPa to 500 kPa.

15. The pressure sensing device according to claim 1, characterized in that, The elastic layer has open, hollowed-out, or thinned areas corresponding to the first electrode and the second electrode.

16. The pressure sensing device according to claim 15, characterized in that, An insulating protective layer is provided on the upper surface of the first electrode and the second electrode, and the thickness of the insulating protective layer is less than 2 μm.

17. The pressure sensing device according to claim 1, characterized in that, The conductive top layer is electrically connected to the ground terminal or reference voltage terminal on the circuit board via conductive jumpers, conductive silver paste, conductive tape, or flexible ribbon cable disposed at the edge of the circuit board.

18. An array-type pressure sensing device, characterized in that, include: A circuit board having multiple driving lines extending along a first direction and multiple sensing lines extending along a second direction, wherein the first direction and the second direction intersect, such that the driving lines and the sensing lines form multiple intersection points on the projection. At each of the said intersections, the drive line connects to a first electrode as described in any one of claims 1 to 17, and the induction line connects to a second electrode as described in any one of claims 1 to 17, wherein the first electrode and the second electrode are coplanar and close to each other, and there is a horizontal capacitance between them; An insulating elastic layer covers the first electrode and the second electrode at each of the said intersections; A conductive top layer covers the elastic layer, and each of the first electrode and the second electrode forms a vertical capacitance with the conductive top layer, and the conductive top layer is grounded or connected to a reference voltage; as well as A detection circuit, connected to each of the driving lines and each of the sensing lines, is used to detect the mutual capacitance between the first electrode and the second electrode at each of the intersection points.

19. The array-type pressure sensing device according to claim 18, characterized in that, The detection circuit applies excitation signals to each of the driving lines in a time-division scanning manner, and reads the coupling signals from all sensing lines when each driving line is excited, so as to obtain the mutual capacitance data matrix of each intersection point.

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