Touch positioning pressure sensing module and preparation method thereof

Abstract

The invention belongs to the technical field of sensors, and particularly relates to a touch positioning pressure sensing module and a preparation method thereof. The sensing module comprises a top insulation packaging layer, an upper layer electrode, an insulation film layer, a mixed conductive layer and an input electrode which are stacked in sequence from top to bottom to form an upper layer integrated structure, wherein the input electrode is stacked at the lower right part of the mixed conductive layer; the bottom insulation packaging layer and the bottom electrode are stacked from bottom to top to form a lower layer integrated structure; the upper-layer integrated structure and the lower-layer integrated structure are connected through a first insulating spacer and a second insulating spacer, and a middle gas cavity is formed by the first insulating spacer, the second insulating spacer, the upper-layer integrated structure and the lower-layer integrated structure; the upper-layer electrode, the input electrode and the bottom electrode are all connected with wires; according to the method, the problem of mutual interference of common dual-mode sensor signals is avoided, meanwhile, the complex process that the signals need to be input into a decoupling algorithm model is also avoided, and back-end data processing tasks are greatly reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of sensors, and in particular relates to a touch positioning pressure sensing module and a preparation method thereof. Background Art

[0002] With the collaboration of electronic science, materials science, and computer science, bionic skin sensors have received widespread attention and have made great progress. They reproduce the skin's ability to perceive external stimuli to a certain extent by converting sensor information such as pressure information or position information into electrical signals; pressure and position signals are also two very commonly used signals in human-computer interaction and intelligent control. Pressure sensors are often used to measure pressure, and touch sensors can be used to sense position. When used alone, they can give the measured data very well, but it is difficult to measure these two sets of data at the same time. At present, the main ways to obtain pressure size and position information at the same time are: row and column matrix circuits quickly scan pressure signals at different intersections, tactile array sensors, hybrid sensors, etc. However, the design methods of these dual-modal sensors use multiple sensing technologies and require more complex design and manufacturing processes, which not only increases the development cycle, but may also lead to a higher error rate in the manufacturing process. At the same time, different types of sensing technologies may have different sensitivities to the environment, such as magnetic fields, electric fields, temperature, etc. These factors may cause signal interference and noise problems, affecting the accuracy and stability of the measurement. In addition, in order to effectively integrate the data provided by different sensing technologies, hybrid sensors require complex algorithms to process and analyze the data, which may increase the computing load of the system and require stronger processor performance.

[0003] In summary, how to effectively obtain two high-precision sensing signals at the same time, simplify the dual-modal sensor structure of pressure and position information, and avoid the complex process of requiring algorithms to process and analyze data, and meet the needs of richer and more multi-dimensional human-computer interaction operations are important issues that need to be urgently solved in the development of flexible sensors. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention proposes a touch positioning pressure sensing module and a preparation method thereof, wherein the sensing module comprises: a top insulating packaging layer, an upper electrode, an insulating film layer, a mixed conductive layer, a first insulating gasket, a second insulating gasket, a bottom electrode, a bottom insulating packaging layer and an input electrode; the top insulating packaging layer, the upper electrode, the insulating film layer, the mixed conductive layer and the input electrode are stacked in sequence from top to bottom to form an upper integrated structure, wherein the input electrode is stacked at the lower right corner of the mixed conductive layer; the bottom insulating packaging layer and the bottom electrode are stacked from bottom to top to form a lower integrated structure; the upper integrated structure and the lower integrated structure are connected through a first insulating gasket and a second insulating gasket, and an intermediate gas cavity is formed by the first insulating gasket, the second insulating gasket, the upper integrated structure and the lower integrated structure; the upper electrode, the input electrode and the bottom electrode are all connected to wires.

[0005] Preferably, the intermediate gas cavity is filled with an inert gas, and the inert gas is one of nitrogen, helium, argon, neon, xenon, and krypton.

[0006] Preferably, the mixed conductive layer is formed by mixing a polymer matrix and a high dielectric filling material; the polymer matrix is ​​one or more of polydimethylsiloxane, polyethylene terephthalate, polytetrafluoroethylene, polyimide, silica gel, and BASF copolyester; the high dielectric filling material is one or more of graphene, carbon nanotubes, conductive carbon black, metal nanoparticles, and metal nanowires.

[0007] Furthermore, the mass fraction of the high dielectric filler material in the mixed conductive layer is in the range of 2.14% to 6.27%.

[0008] Preferably, the ratio of the thickness of the mixed conductive layer to the thickness of the first insulating spacer is in the range of 1:1 to 1:3.

[0009] Preferably, the material of the top insulating packaging layer, the insulating film layer and the bottom insulating packaging layer is one or more of polydimethylsiloxane, polyimide, polyparaxylene, polyurethane, epoxy resin and polyester.

[0010] A method for preparing a touch positioning pressure sensing module, characterized by comprising:

[0011] S1: stirring and mixing a high dielectric filler material and a high molecular polymer matrix according to a mass fraction ratio of the high dielectric filler material of 2.14% to 6.27% to obtain a conductive mixture;

[0012] S2: using a laser cutting machine to cut the polyethylene terephthalate film to obtain a top insulating packaging layer, an insulating film layer and a bottom insulating packaging layer; and setting one or more filling holes in the top packaging layer;

[0013] S3: cleaning the top insulating packaging layer, the insulating film layer and the bottom insulating packaging layer, and plating an upper electrode and a bottom electrode on the lower surface of the top insulating packaging layer and the upper surface of the bottom insulating packaging layer respectively;

[0014] S4: stacking the top insulating packaging layer, insulating film layer, conductive mixture and copper sheet plated with the upper electrode in sequence from top to bottom to form an upper integrated structure;

[0015] S5: using the bottom insulating packaging layer plated with the bottom electrode as the lower integrated structure, and using an adhesive to bond the first insulating gasket and the second insulating gasket between the upper integrated structure and the lower integrated structure to form an intermediate gas cavity in the middle;

[0016] S6: Use conductive silver glue to connect wires at the right end of the input electrode, the top of the upper electrode, and the bottom of the bottom electrode;

[0017] S7: placing the device obtained in step S6 in a vacuum chamber, extracting the air in the intermediate gas cavity through the filling hole; injecting an inert gas into the intermediate gas cavity through the filling hole and quickly sealing the filling port to obtain a prepared touch positioning pressure sensing module.

[0018] Furthermore, in step S4, the process of forming the upper integrated structure includes:

[0019] S41: After aligning the insulating film layer with the top insulating encapsulation layer plated with the upper electrode, heat and pressurize them by a hot press laminator to firmly combine them together; the lamination temperature is set at 100-150°C and the pressure is 1-5Mpa;

[0020] S42: uniformly coating the conductive mixture on the surface of the device obtained in step S41, and controlling the ratio of the conductive mixture to the first insulating spacer to be within a range of 1:1 to 1:3;

[0021] S43: placing the device obtained in step S42 in an oven for treatment at a temperature of 45 degrees Celsius for 70 minutes;

[0022] S44: Use conductive silver glue to stick a copper sheet of the same size as the second insulating gasket to the lower right side of the device obtained in step S43 to obtain an upper integrated structure.

[0023] The beneficial effects of the present invention are as follows: the present invention greatly simplifies the structure and manufacturing process of the traditional dual-modal sensor, shortens the manufacturing cycle, and reduces the manufacturing cost; the mixed conductive layer in the present invention is a mixture of high dielectric filling materials added to a polymer material base, which not only maintains the sensitivity of the capacitive pressure sensing module but also maintains good conductivity, so that the sensor can simultaneously measure the position of the pressure; the thickness of the mixed conductive layer is selected to improve the overall stability of the sensor while taking into account the detection lower limit of the touch positioning module; the present invention adopts a conductive dielectric layer and three electrodes to realize the simultaneous detection of two signals of pressure and position information, and the pressure and position respectively adopt capacitive and resistive pressure sensing principles to collect capacitance value changes and resistance value changes, avoiding the problem of mutual interference of general dual-modal sensor signals, and also avoiding the complex process of signal input decoupling algorithm model, greatly reducing the back-end data processing tasks; the present invention has broad application prospects in the fields of electronic skin, human-computer interaction, feature characterization, and decision support. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the structure of the touch positioning pressure sensing module in the present invention;

[0025] Figure 2 This is a schematic diagram of a signal detection circuit of a touch positioning pressure sensing module in the present invention;

[0026] Figure 3 This is a schematic diagram of the pressure sensing principle of the touch positioning pressure sensing module of the present invention for sensing pressure at the same position;

[0027] Figure 4 This is a schematic diagram of the sensing principle of the touch positioning pressure sensing module of the present invention for sensing the positioning information of different positions under the same pressure;

[0028] In the figure: 1. Top insulating packaging layer; 2. Upper electrode; 3. Insulating film layer; 4. Mixed conductive layer; 5. First insulating gasket; 6. Bottom electrode; 7. Bottom insulating packaging layer; 8. Input electrode; 9. Second insulating gasket; 10. Intermediate gas cavity. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] The present invention proposes a touch positioning pressure sensing module and a preparation method thereof. Figure 1As shown, the sensing module includes: a top insulating packaging layer 1, an upper electrode 2, an insulating film layer 3, a mixed conductive layer 4, a first insulating gasket 5, a second insulating gasket 9, a bottom electrode 6, a bottom insulating packaging layer 7 and an input electrode 8; the top insulating packaging layer 1, the upper electrode 2, the insulating film layer 3, the mixed conductive layer 4 and the input electrode 8 are stacked in sequence from top to bottom to form an upper integrated structure; specifically: in the upper integrated structure, the upper electrode 2 is attached to the lower surface of the top insulating packaging layer 1, the insulating film layer 3 is attached to the lower surface of the upper electrode 2, the mixed conductive layer 4 is coated on the lower surface of the insulating film 3, and the input electrode 8 is attached to the right side of the lower surface of the mixed conductive layer 4.

[0031] The bottom insulating packaging layer 7 and the bottom electrode 6 are stacked from bottom to top to form a lower integrated structure; that is, in the lower integrated structure, the bottom electrode 6 is attached to the upper surface of the bottom insulating packaging layer 7 .

[0032] The upper integrated structure and the lower integrated structure are connected by the first insulating gasket 5 and the second insulating gasket 9. Specifically, the first insulating gasket 5 and the second insulating gasket 9 are respectively attached to the left and right sides of the bottom electrode 6, and the upper integrated structure is attached to the first insulating gasket 5 and the second insulating gasket 9; and an intermediate gas cavity 10 is formed by the first insulating gasket 5, the second insulating gasket 9, the upper integrated structure and the lower integrated structure; the upper electrode 2, the input electrode 8 and the bottom electrode 6 are all connected to the wires (21, 81, 61).

[0033] In the touch positioning pressure sensing module of the present invention, the upper electrode 2 and the bottom electrode 6 constitute the parallel electrode plates of the capacitive pressure sensing module; the insulating film layer 3, the mixed conductive layer 4, the insulating gaskets 5, 9 and the intermediate gas cavity 10 stacked in sequence together constitute the capacitive medium of the capacitive pressure sensing module. The parallel electrode plates, the capacitive medium and the wires 21, 61 together constitute the capacitive pressure sensing module. The input electrode 8, the bottom electrode 6, the mixed conductive layer 4 and the wires 81, 61 together constitute the touch positioning sensing module. When the mixed conductive layer 4 or the bottom electrode 6 is subjected to pressure, the mixed conductive layer 4 at the pressure point passes through the intermediate gas cavity 10 to make contact with the bottom electrode 6, and a conductive path is formed between the input electrode 8 and the bottom electrode 6, realizing the function of measuring position and pressure at the same time. Therefore, the mixed conductive layer 4 is both a capacitive dielectric material and a high resistance layer of the touch positioning module. The bottom electrode 6 is both the bottom electrode plate of the capacitive pressure sensing module and the low resistance layer and output electrode of the touch positioning module.

[0034] In some preferred embodiments, the intermediate gas cavity 10 is filled with an inert gas, and the inert gas is one of nitrogen N2, helium He, argon Ar, neon Ne, xenon Xe, and krypton Kr. In the present invention, the gas cavity is filled with an inert gas, which can effectively improve the stability of the sensor module, extend the service life of the sensor, and improve the accuracy of the sensor. The chemical properties of the inert gas are very stable and will not chemically react with the materials inside the sensor, thereby preventing the components inside the sensor from being oxidized or corroded, and extending the service life of the sensor. In addition, the dielectric constant of the inert gas is stable and low. When the pressure changes, the capacitance change of the medium is mainly caused by the physical change of the sensor structure, rather than by the change of the gas properties, thereby improving the accuracy of the sensor.

[0035] In some preferred embodiments, the mixed conductive layer is formed by mixing a polymer matrix and a high dielectric filling material; wherein the polymer material is one or more of polydimethylsiloxane PDMS, polyethylene terephthalate PET, polytetrafluoroethylene PTFE, polyimide PI, silicone rubber, and BASF copolyester Ecoflex; the high dielectric filling material is one or more of graphene, carbon nanotubes, conductive carbon black, metal nanoparticles, and metal nanowires; in the present invention, the preferred scheme for the mixed conductive layer material is polydimethylsiloxane PDMS and carbon nanotubes CNTs.

[0036] In some preferred embodiments, the mass fraction of high dielectric filler material in the mixed conductive layer is in the range of 2.14% to 6.27%. When too little high dielectric material is added, there is less conductive material per unit area, and the number of materials that can overlap each other is relatively small. The conductive path is not fully formed, and the conductivity of the composite material is low at this time, which will affect the function of the touch positioning module. As the content of the conductive material increases, the spacing between the conductive particles decreases. When the spacing is reduced to a certain extent, electron tunneling characteristics will occur between the conductive material particles, and conduction will be achieved, showing semiconductor characteristics. At this time, the conductive function and the capacitor medium function can be satisfied at the same time. However, when too much conductive material is added, on the one hand, as the content of the high dielectric material further increases, the high dielectric material agglomerates in the matrix and makes it unevenly dispersed, resulting in a decrease in the conductivity of the composite material. On the other hand, the conductive particles are in contact and connected, and there is no capacitance characteristic between the particles, and the capacitance value is reduced. Therefore, when the conductive material is at a high concentration, the capacitance sensitivity factor is reduced, which will affect the function of the capacitive pressure sensing module. Therefore, when the mass fraction of high dielectric materials (the mass fraction of high dielectric constant materials in high molecular polymer materials) is in the range of 2.14% to 6.27%, the sensitivity of the capacitive pressure sensing module can be maintained while maintaining good conductivity, so that the sensor can simultaneously measure the pressure position.

[0037] A thinner dielectric layer and a thicker gas layer (such as a ratio of 1:4 to 1:5) can increase the capacitance change rate, thereby increasing sensitivity and response speed. However, a thicker gas layer will cause the mixed conductive layer 4 and the bottom electrode 6 to fail to form a conductive path when slightly pressed, thereby reducing the detection limit of the touch positioning module. When the dielectric layer is relatively thick (such as a ratio of 1:1 to 1:3), the overall stability of the sensor can be improved while taking into account the detection limit of the touch positioning module. In some preferred embodiments, the ratio of the thickness of the mixed conductive layer to the thickness of the first insulating gasket is in the range of 1:1 to 1:3.

[0038] In some preferred embodiments, the materials of the top insulating packaging layer, the insulating film layer and the bottom insulating packaging layer are one or more electrically insulating materials including polydimethylsiloxane (PDMS), polyimide (PI), polyparaxylene (Parylene), polyurethane (PU), epoxy resin and polyester (PET).

[0039] Compared with the existing dual-mode sensor, the sensor module of the present invention adopts a structural design that shares a functional layer 4 (mixed conductive layer) and a bottom electrode 6 and connects 3 wires to realize the perception of force and position. The sensor module of the present invention is based on the improved design of the capacitive pressure sensor, and the mixed conductive layer 4 is both a capacitor dielectric material layer and a high resistance material of the touch positioning module. The bottom electrode 6 is both the bottom electrode plate of the capacitive pressure sensing module and a low resistance material and output electrode of the touch positioning module. On the one hand, this design greatly simplifies the structure and manufacturing process of the traditional dual-mode sensor, shortens the manufacturing cycle, and reduces the manufacturing cost. On the other hand, the traditional touch positioning sensor generally requires M×N×2 electrodes (M and N are the number of longitude and latitude lines of the touch point), which makes the transmission and processing of the signal very complicated and cannot meet the complex signal processing such as multi-touch. At present, some progress has been made in the touch positioning sensor. Through structural design, the number of electrodes can be reduced to M×N+1 or M+N, shortening the measurement time and simplifying the signal processing process. However, these touch positioning sensors are either unstable and susceptible to signal interference, or have a complex structure and a large number of electrodes. The touch positioning pressure sensing module of the present invention uses a conductive dielectric layer and three electrodes to simultaneously detect two signals, pressure and position information, and the pressure and position use capacitive and resistive pressure sensing principles respectively, which reduces coupling interference and avoids complex decoupling processes.

[0040] The present invention also provides a method for preparing a touch positioning pressure sensing module, comprising:

[0041] S1: stirring and mixing a high dielectric filler material and a high molecular polymer matrix according to a mass fraction ratio of the high dielectric filler material of 2.14% to 6.27% to obtain a conductive mixture.

[0042] Use 40 ml of organic solvent ethanol or DMF as a dispersion medium, and disperse 0.2 g of carbon nanotubes therein; use an ultrasonic cleaner to perform ultrasonic treatment on the carbon nanotube dispersion to obtain a carbon nanotube dispersion.

[0043] Take 4.53 g of polydimethylsiloxane matrix, and stir and mix the carbon nanotube dispersion and 4.53 g of polydimethylsiloxane matrix at room temperature using a magnetic stirrer for 20 minutes, setting the stirring speed to 300 RPM, i.e., 300 revolutions per minute, to obtain a mixture.

[0044] S2: using a laser cutting machine to cut the polyethylene terephthalate film to obtain a top insulating packaging layer, an insulating film layer and a bottom insulating packaging layer; and setting one or more filling holes in the top packaging layer.

[0045] A laser cutting machine is used to cut a polyethylene terephthalate film with a thickness of 0.2 mm into three rectangular strips with an aspect ratio of 64:9, one of which is used as a top insulating packaging layer, and the other two are used as an insulating film layer and a bottom insulating packaging layer, and one or more filling holes are set in the top packaging layer; wherein, during cutting, the laser tube power is 8W, and the cutting speed is 15mm / s.

[0046] S3: Clean the top insulating packaging layer, the insulating film layer and the bottom insulating packaging layer, and plate an upper electrode and a bottom electrode on the lower surface of the top insulating packaging layer and the upper surface of the bottom insulating packaging layer respectively.

[0047] Use an ultrasonic cleaner to add diluted propanol (mix 20 ml of 70% propanol with deionized water in a volume ratio of 1:4) to thoroughly clean the surfaces of the three PET films obtained in step S2. Ensure that oil, dust and other contaminants on the surface are removed.

[0048] Two clean PET films, namely the top insulating packaging layer and the bottom insulating packaging layer, are placed on the sample stage of the sputtering equipment, and a metal target is installed. The distance between the target and the PET film is set to 10-15 cm. The target is cleaned and pre-treated to remove possible contaminants on the surface; the sputtering equipment is turned on for sputtering treatment, and the vacuum degree of the sputtering process is set to 10^-6 to 10^-8 Torr. Argon (Ar) is used as the sputtering gas, and the argon flow rate is set to 20-50sccm (standard cubic centimeters per minute); the sputtering power is usually set between 50-300W, the power density is set in the range of 1-3W / cm2, and the sputtering time is 5-20 minutes. After the sputtering is completed, the sample is cooled in a vacuum environment to obtain a top insulating packaging layer 1 with a metal film (coated with the upper electrode 2) and a lower integrated structure (coated with the bottom electrode 6 on the insulating layer 7).

[0049] S4: stacking the top insulating packaging layer, insulating film layer, conductive mixture and copper sheet plated with the upper electrode in sequence from top to bottom to form an upper integrated structure.

[0050] S41: After aligning the insulating film layer with the top insulating packaging layer plated with the upper electrode, heat and pressurize them through a hot pressing laminator to firmly combine them together; the lamination temperature is set at 100-150°C and the pressure is 1-5Mpa.

[0051] S42: uniformly coating the conductive mixture on the surface of the device obtained in step S41, and controlling the ratio of the conductive mixture to the first insulating spacer to be within a range of 1:1 to 1:3

[0052] The mixture is formed into a desired shape so that the ratio of its thickness to the first insulating spacer is in the range of 1:1 to 1:3.

[0053] S43: The device obtained in step S42 is placed in an oven for treatment at a temperature of 45 degrees Celsius for 70 minutes.

[0054] S44: Use conductive silver glue to stick a copper sheet of the same size as the second insulating gasket to the lower right side of the device obtained in step S43 to obtain an upper integrated structure.

[0055] After pasting is completed, the sample is cured in the environment to obtain an upper integrated structure.

[0056] S5: The bottom insulating encapsulation layer plated with the bottom electrode is used as the lower integrated structure, and the first insulating gasket and the second insulating gasket are bonded between the upper integrated structure and the lower integrated structure using an adhesive to form an intermediate gas cavity in the middle. The insulating gasket is one of polytetrafluoroethylene PET, polyimide Kapton, polyethylene PE, polypropylene PP and polyethylene terephthalate PET.

[0057] Adhesive (epoxy resin glue, acrylic glue, silicone rubber glue, thermal conductive adhesive) is used to stick insulating gasket 5 and insulating gasket 9 on both sides of the surface of the lower integrated structure with metal film at a distance of 2mm from the port. The sum of the thickness of the insulating gasket 5 and the input electrode is equal to the thickness of the insulating gasket 9; preferably, the insulating gasket 5 is 2mm long, 3mm wide, and 4mm thick, and the insulating gasket 9 is 2mm long, 3mm wide, and 3.9mm thick; align one side of the upper integrated structure with the mixed conductive layer 4 and place it on the lower integrated structure with insulating gaskets 5 and 9 pasted on both sides. After pressing and pasting, an intermediate gas cavity is formed in the middle.

[0058] S6: Use conductive silver glue to connect wires at the right end of the input electrode, the top of the upper electrode, and the bottom of the bottom electrode.

[0059] Conductive silver paste is used to lead out a wire 81 at the right end of the input electrode 8. Conductive silver paste is used to lead out wires 21 and 61 at the top of the upper electrode and the right end of the bottom of the bottom electrode.

[0060] S7: placing the device obtained in step S6 in a vacuum chamber, extracting the air in the intermediate gas cavity through the filling hole set in step S2; injecting inert gas into the intermediate gas cavity through the filling hole and quickly sealing the filling port to obtain a prepared touch positioning pressure sensing module.

[0061] After the middle gas cavity is filled with inert gas, a flexible touch positioning pressure sensing module that can simultaneously detect pressure and position information is obtained, wherein the inert gas is one of nitrogen, helium, argon, neon, xenon, and krypton.

[0062] When the touch positioning pressure sensing module designed by the present invention is used, the touch positioning pressure sensing module is connected to the detection circuit; Figure 2 As shown, the detection circuit includes a touch positioning pressure sensing module, a capacitance digital converter (CDC) 401, a resistance detection module 402, and a constant voltage source 403. The sensing module input electrode 2 and the input electrode 8 are connected to the constant voltage source 403, and the output electrode 6 is connected to the capacitance digital converter (CDC) 401 and the resistance detection module 402. At the same time, the capacitance digital converter (CDC) 401 and the resistance detection module 402 are connected to the constant voltage source.

[0063] The touch positioning pressure sensing module is connected to the capacitance digital converter 401 (CDC) through the upper electrode / bottom electrode. Figure 3 In the figure, (a) is a cross-sectional view of the touch positioning pressure sensing module under slight pressure, and (b) is a cross-sectional view of the touch positioning pressure sensing module under greater pressure. Figure 3 As shown in (a), the intermediate gas cavity 10 is compressed, and the distance between the upper electrode 2 and the bottom electrode 6 parallel electrode plates becomes smaller; when the pressure is increased, as shown in Figure 3 As shown in (b), the dielectric layer 4 is further compressed and the deformation increases, so that the capacitance in the capacitive pressure sensing module increases.

[0064] Figure 4 In FIG. 1 , (a)-(d) are cross-sectional views of the touch positioning pressure sensing module when different positions are pressed; when the same pressure is applied to different positions, such as Figure 4 (a) is the static state of the sensor. When subjected to a certain pressure, Figure 4 (b), the upper integrated structure of the touch positioning pressure sensing module produces a certain deformation, and the conductive mixed layer 4 and the bottom electrode 6 form an electrical contact structure. The current flows in from the input electrode 8 and flows through the output electrode layer 6 at the pressed position. When the pressed position is changed, Figure 4As shown in (b)-(d), the deformation degree of the conductive mixed layer 4 at the pressing point is basically the same, but the current in the connected circuit shows different changes when the pressing position is different. The closer the pressing position is to the right electrode 8, the greater the current, and vice versa, the current decreases, which proves the ability to sense and identify different positions.

[0065] In summary, the touch positioning pressure sensing module designed by the present invention collects changes in capacitance and resistance values, avoiding the problem of mutual interference between general dual-modal sensor signals, and also avoiding the complex process of signal input decoupling algorithm model, greatly reducing the back-end data processing tasks. Based on the force on the sensor, two conductive paths are generated between the sensing layers. Different pressures and different force positions will change the electrical signal values ​​of the two paths. By analyzing the strength of the two electrical signal values, the pressure size and force position can be accurately identified. The present invention can be attached to human skin or any other surface to detect pressure stimulation at different positions on the surface of an object. It can also be used in human-computer interaction scenarios, giving full play to the synergistic advantages of two-dimensional signals, and providing rich interactive instructions for sensing targets. The touch positioning pressure sensing module has a wide range of applications in the fields of electronic skin, human-computer interaction, feature characterization, and decision support.

[0066] The above embodiments further illustrate the purpose, technical solutions and advantages of the present invention in detail. It should be understood that the above embodiments are only preferred implementation modes of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made to the present invention within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A touch positioning pressure sensing module, characterized in that: include: A top insulating packaging layer, an upper electrode, an insulating film layer, a mixed conductive layer, a first insulating gasket, a second insulating gasket, a bottom electrode, a bottom insulating packaging layer and an input electrode; The top insulating packaging layer, the upper electrode, the insulating film layer, the mixed conductive layer and the input electrode are stacked in sequence from top to bottom to form an upper integrated structure, wherein the input electrode is stacked at the lower right of the mixed conductive layer; the bottom insulating packaging layer and the bottom electrode are stacked from bottom to top to form a lower integrated structure; The upper integrated structure is connected to the lower integrated structure through the first insulating gasket and the second insulating gasket, and an intermediate gas cavity is formed by the first insulating gasket, the second insulating gasket, the upper integrated structure and the lower integrated structure; the upper electrode, the input electrode and the bottom electrode are all connected to the wire.

2. The touch positioning pressure sensing module according to claim 1, characterized in that: The intermediate gas cavity is filled with an inert gas, and the inert gas is one of nitrogen, helium, argon, neon, xenon, and krypton.

3. The touch positioning pressure sensing module according to claim 1, characterized in that: The mixed conductive layer is formed by mixing a high molecular polymer matrix and a high dielectric filling material; the high molecular polymer matrix is ​​one or more of polydimethylsiloxane, polyethylene terephthalate, polytetrafluoroethylene, polyimide, silica gel, and BASF copolyester; the high dielectric filling material is one or more of graphene, carbon nanotubes, conductive carbon black, metal nanoparticles, and metal nanowires.

4. The touch positioning pressure sensing module according to claim 3, characterized in that: The mass fraction of the high dielectric filling material in the mixed conductive layer is in the range of 2.14% to 6.27%.

5. The touch positioning pressure sensing module according to claim 1, characterized in that: The ratio of the thickness of the mixed conductive layer to the thickness of the first insulating spacer is in the range of 1:1 to 1:

3.

6. The touch positioning pressure sensing module according to claim 1, characterized in that: The materials of the top insulating packaging layer, the insulating film layer and the bottom insulating packaging layer are one or more of polydimethylsiloxane, polyimide, polyparaxylene, polyurethane, epoxy resin and polyester.

7. A method for preparing a touch positioning pressure sensing module, characterized in that: include: S1: stirring and mixing a high dielectric filler material and a high molecular polymer matrix according to a mass fraction ratio of the high dielectric filler material of 2.14% to 6.27% to obtain a conductive mixture; S2: using a laser cutting machine to cut the polyethylene terephthalate film to obtain a top insulating packaging layer, an insulating film layer and a bottom insulating packaging layer; and setting one or more filling holes in the top packaging layer; S3: cleaning the top insulating packaging layer, the insulating film layer and the bottom insulating packaging layer, and plating an upper electrode and a bottom electrode on the lower surface of the top insulating packaging layer and the upper surface of the bottom insulating packaging layer respectively; S4: stacking the top insulating packaging layer, insulating film layer, conductive mixture and copper sheet plated with the upper electrode in sequence from top to bottom to form an upper integrated structure; S5: using the bottom insulating packaging layer plated with the bottom electrode as the lower integrated structure, and using an adhesive to bond the first insulating gasket and the second insulating gasket between the upper integrated structure and the lower integrated structure to form an intermediate gas cavity in the middle; S6: Use conductive silver glue to connect wires at the right end of the input electrode, the top of the upper electrode, and the bottom of the bottom electrode; S7: placing the device obtained in step S6 in a vacuum chamber, extracting the air in the intermediate gas cavity through the filling hole; injecting an inert gas into the intermediate gas cavity through the filling hole and quickly sealing the filling port to obtain a prepared touch positioning pressure sensing module.

8. The method for preparing a touch positioning pressure sensing module according to claim 7, characterized in that: In step S4, the process of forming the upper integrated structure includes: S41: After aligning the insulating film layer with the top insulating encapsulation layer plated with the upper electrode, heat and pressurize them by a hot press laminator to firmly combine them together; the lamination temperature is set at 100-150°C and the pressure is 1-5Mpa; S42: uniformly coating the conductive mixture on the surface of the device obtained in step S41, and controlling the ratio of the conductive mixture thickness to the first insulating spacer to be within a range of 1:1 to 1:3; S43: placing the device obtained in step S42 in an oven for treatment at a temperature of 45 degrees Celsius for 70 minutes; S44: Use conductive silver glue to stick a copper sheet of the same size as the second insulating gasket to the lower right side of the device obtained in step S43 to obtain an upper integrated structure.

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