Directional sound emitting screen and preparation process thereof

Abstract

The application discloses a directional sound emitting screen and a preparation process thereof, which comprises a vibration layer, a non-vibration layer, a pattern layer and an insulation layer, wherein the vibration layer comprises a first conductive layer, and the non-vibration layer comprises a second conductive layer; the pattern layer is located between the first conductive layer and the second conductive layer, and the insulation layer is located between the pattern layer and the first conductive layer or between the pattern layer and the second conductive layer, and the insulation layer is an ink layer doped with anti-static microspheres. The application dopes anti-static microspheres in the ink insulation medium of the directional sound emitting screen, so as to improve the stability of the ink insulation medium, make the ink insulation medium not easy to lose charges, reduce the accumulation of surface static electricity, greatly reduce the influence of the charges generated by air ionization on the air partial pressure, and then improve the reliability and sound pressure of the directional sound emitting screen.

Description

Technical Field

[0001] This invention relates to the field of directional sound generation technology, specifically to a directional sound generation screen and its manufacturing process. Background Technology

[0002] Electrostatic thin-film ultrasonic transducers, also known as capacitive thin-film ultrasonic transducers, utilize the electrostatic force generated by the upper and lower electrodes to drive the thin film to vibrate, thereby radiating ultrasonic waves.

[0003] A typical electrostatic thin-film ultrasonic transducer structure generally includes, from top to bottom, a vibrating substrate layer, a top electrode, a patterned layer, an insulating layer, a bottom electrode, and a non-vibrating substrate layer, with an air gap between the top electrode and the insulating layer. A DC bias voltage Vdc and an AC voltage Vac are applied between the top and bottom electrodes to drive the vibrating substrate layer to vibrate and produce sound.

[0004] However, when the applied voltage increases, the air in the air gap will ionize. Ionization increases the conductivity of the air, which leads to a decrease in the partial pressure of the air. This, in turn, reduces the ultrasonic pressure radiated by the electrostatic thin-film ultrasonic transducer, thus degrading the transducer's performance.

[0005] Therefore, how to reduce the impact of air ionization on the reliability and sound pressure of electrostatic thin-film ultrasonic transducers is a problem that needs to be solved. Summary of the Invention

[0006] The purpose of this invention is to provide a directional sound-emitting screen and its manufacturing process that can effectively reduce the impact of air ionization on the reliability and sound pressure of the directional sound-emitting screen.

[0007] To achieve the above objectives, in one aspect, the present invention proposes a directional sound-emitting screen, comprising:

[0008] A vibration layer, comprising a vibration substrate layer and a first conductive layer, wherein the entire surface of the first conductive layer is formed on the surface of the vibration substrate layer near the non-vibration layer;

[0009] A non-vibrating layer is attached to the frame of the vibrating layer. The non-vibrating layer includes a non-vibrating substrate layer and a second conductive layer. The entire surface of the second conductive layer is formed on the surface of the non-vibrating substrate layer near the vibrating layer.

[0010] The patterned layer is located between the first conductive layer and the second conductive layer. After the vibrating layer is attached to the frame of the non-vibrating layer, an air gap is formed between the patterned layer and the non-vibrating layer to allow the vibrating layer to vibrate up and down and produce sound. The patterned layer consists of multiple spaced insulating units.

[0011] An insulating layer is located between the patterned layer and the first conductive layer or between the patterned layer and the second conductive layer, wherein the insulating layer is an ink layer doped with antistatic microspheres.

[0012] In a preferred embodiment, the antistatic microspheres include any one of silica spherical powder, polytetrafluoroethylene spherical powder, acrylic copolymer spherical powder, and organic compound spherical powder.

[0013] In a preferred embodiment, the diameter of the antistatic microspheres is 0.2 μm to 20 μm, and the total amount of the antistatic microspheres is between 0.5% and 30% of the total amount of the ink layer before the antistatic microspheres are removed and after the moisture is removed.

[0014] In a preferred embodiment, the insulating layer is formed entirely on the surface of the second conductive layer near the vibrating layer by screen printing, or entirely on the surface of the first conductive layer near the non-vibrating layer.

[0015] In a preferred embodiment, each of the insulating units includes a plurality of insulating protrusions arranged in a square, with the sides of the square parallel to the sides of the corresponding non-vibrating substrate layer or vibrating substrate layer. The plurality of insulating units are arranged in an array to form a plurality of array units.

[0016] In a preferred embodiment, a support point is provided at the center of each array unit. The support point is a single point or a multi-point structure, and the height of the support point is less than the height of the insulating protrusion; or the conductive layer corresponding to the center of each array unit is removed to form a non-conductive layer portion.

[0017] In a preferred embodiment, the height of the support point is 2um to 4um, the height of the insulating bump is 7um to 12um, and the spacing between two adjacent array units is 2.2um to 2.8um.

[0018] In a preferred embodiment, the pattern layer and the insulating layer are fixed together by an adhesive layer, which is a plurality of spaced adhesive unit structures corresponding to the structure of the pattern layer or is a whole surface.

[0019] In a preferred embodiment, a waterproof layer is further provided on the outermost surface of the vibrating layer away from the non-vibrating layer, and the thickness of the waterproof layer is 1µm to 10µm.

[0020] On the other hand, the present invention proposes a manufacturing process for a directional sound-emitting screen, wherein the directional sound-emitting screen is the aforementioned directional sound-emitting screen, and the manufacturing process includes:

[0021] S1, Prepare the vibration layer, including making a first conductive layer on the entire surface of the vibration substrate layer near the non-vibration layer;

[0022] S2, Prepare a non-vibrating layer, including making a second conductive layer on the entire surface of the non-vibrating substrate layer near the vibrating layer;

[0023] S3, a patterned layer is formed on the surface of the first conductive layer near the non-vibrating layer or on the surface of the insulating layer near the vibrating layer;

[0024] S4. An ink layer doped with antistatic microspheres is formed on the surface of the second conductive layer near the vibrating layer or on the surface of the first conductive layer near the non-vibrating layer as an insulating layer. The insulating layer covers the pattern layer or directly covers the corresponding conductive layer on the entire surface.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. This invention improves the stability of the ink insulating medium by doping it with antistatic microspheres, making it less prone to losing charge and reducing the accumulation of static electricity on its surface. This greatly reduces the impact of charge generated by air ionization on air partial pressure.

[0027] 2. By readjusting the pattern arrangement and spacing of the pattern layer, this invention facilitates the printing of the pattern layer and increases the bonding area between the pattern layer and the vibrating or non-vibrating layer. This makes the vibrating and non-vibrating layers more stable and allows for uniform tension diffusion on the vibrating layer, which helps improve the reliability of the formed directional sound-emitting screen.

[0028] 3. The present invention sets a support point or a non-conductive layer at the center of each array unit of the pattern layer, which can suppress the increased distortion caused by the collision between the vibrating layer and the non-vibrating layer at the maximum amplitude of each array unit, thereby preventing reliability failure. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the structure of a directional sound-emitting screen in one embodiment of the present invention;

[0030] Figure 2 This is a schematic diagram of the arrangement structure of the patterned layer in this invention;

[0031] Figure 3 This is a schematic flowchart of the manufacturing process of the directional sound-emitting screen of the present invention.

[0032] The attached figures are labeled as follows:

[0033] 1. Vibrating layer; 11. Vibrating substrate layer; 12. First conductive layer; 13. First edge trace; 2. Non-vibrating layer; 21. Non-vibrating substrate layer; 22. Second conductive layer; 23. Insulating layer; 24. Second edge trace; 3. Pattern layer; 31. Insulating unit; 32. Insulating bump; 33. Array unit; 34. Support point; 4. Antistatic microsphere; 5. Waterproof layer; 6. Adhesive layer. Detailed Implementation

[0034] The specific embodiments of the present invention will be described in detail below, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments.

[0035] Unless otherwise expressly stated, throughout the specification and claims, the term "comprising" or its variations such as "including" or "comprises" shall be understood to include the stated elements or components without excluding other elements or other components.

[0036] like Figure 1 As shown, the directional sound-emitting screen disclosed in this invention includes a vibrating layer 1, a non-vibrating layer 2, and a patterned layer 3, wherein the edges of the vibrating layer 1 and the non-vibrating layer 2 are bonded together. This invention improves the stability of the ink insulating medium by doping it with antistatic microspheres, making it less prone to losing charge and reducing the accumulation of static electricity on its surface. This significantly reduces the impact of air ionization charge on air partial pressure.

[0037] The vibrating layer 1, serving as the acoustic vibration layer, specifically includes a vibrating substrate layer 11 and a first conductive layer 12. In this embodiment, the vibrating substrate layer 11 can be implemented using a flexible film, such as a PET film. The first conductive layer 12 is formed on the entire surface of the vibrating substrate layer 11 near the non-vibrating layer 2. In practice, the first conductive layer 12 can be implemented using high-transmittance materials such as nano-silver, indium tin oxide, metal mesh, carbon nanotubes, or graphene, or it can be a non-transparent conductive material such as copper or copper-doped oxide, silver, or gold. The lower its sheet resistance, the higher the overall sound generation efficiency of the directional sound-emitting screen. Preferably, the sheet resistance is below 10 ohms. In addition, to further improve the conductivity of the first conductive layer 12, a first edge trace 13 can be added at at least one edge of the first conductive layer 12 near the surface of the non-vibrating layer 2. In practice, the first edge trace 13 is also implemented using copper or copper-doped oxide, silver, or gold.

[0038] The non-vibrating layer 2 serves as a non-vibrating substrate layer, specifically comprising a non-vibrating substrate layer 21, a second conductive layer 22, and an insulating layer 23. The second conductive layer 22 is formed over its entire surface on the non-vibrating substrate layer 21 near the vibrating layer 1. Preferably, to improve the conductivity of the second conductive layer 22, a second edge trace 24 can be added at at least one edge of the second conductive layer 22 near the vibrating layer 1. Similarly, in practice, the second edge trace 24 is also implemented using copper, copper-doped oxide, silver, or gold.

[0039] An insulating layer 23 is formed over its entire surface on the surface of the second conductive layer 22 near the vibrating layer 1 and covers the second edge trace 24. This insulating layer 23 serves to separate the first conductive layer 12 and the second conductive layer 22 after the vibrating layer 1 and the non-vibrating layer 2 are bonded together. Alternatively, it can be formed over its entire surface on the surface of the first conductive layer 12 near the non-vibrating layer. Preferably, unlike existing ink layers, this invention incorporates antistatic microspheres 4 into the existing ink. That is, the insulating layer 23 of this invention is an ink layer doped with antistatic microspheres 4, which improves the stability of the ink's insulating medium, making it less prone to losing charge and reducing the accumulation of static electricity on its surface. This significantly reduces the impact of charges generated by air ionization on the air partial pressure.

[0040] In specific implementation, the ink layer is a polyurethane acrylic resin ink, to which a certain proportion of antistatic microspheres 4 can be doped. The antistatic microspheres 4 can be any one of silica spherical powder, polytetrafluoroethylene spherical powder, acrylic copolymer spherical powder, or organic compound spherical powder. The diameter of the antistatic microspheres 4 ranges from 0.2µm to 20µm, and their particle size depends on the thickness of the ink layer. The proportion of different particle sizes of the antistatic microspheres 4 needs to be determined based on their ratio with the polyurethane acrylic resin ink material. Generally, the total amount of antistatic microspheres 4 incorporated accounts for 0.5% to 30% of the total amount of the ink layer before moisture removal and before doping with antistatic microspheres 4. Theoretically, a smaller doping quantity of antistatic microspheres 4 results in a lower probability of suppressing air ionization; conversely, a larger doping quantity can cause breakdown and other defects to some extent. The smaller the diameter of the antistatic microspheres 4, the higher the purity, the more uniform the doping degree, and the more uniform the ability to suppress air ionization.

[0041] In addition, preferably, a waterproof layer 5 is provided on the outermost surface of the vibrating layer 1 away from the non-vibrating layer 2. This prevents the vibrating layer 1 from absorbing water and softening in a high-temperature and high-humidity environment, which would reduce the distance between the vibrating layer electrode and the non-vibrating layer electrode, increase the electric field strength, and thus increase polarization. In practice, the thickness of the waterproof layer 5 can be 1µm to 10µm.

[0042] Preferably, in this embodiment, the pattern layer 3 is located between the first conductive layer 12 and the second conductive layer 22. After the vibrating layer 1 and the non-vibrating layer 2 are attached to each other, an air gap (not shown) is formed between the pattern layer 3 and the non-vibrating layer 2 to allow the vibrating layer 1 to vibrate up and down and produce sound. In practice, the pattern layer 3 can be formed on the surface of the first conductive layer 12 near the non-vibrating layer 2, or on the surface of the insulating layer 23 near the vibrating layer 1. Specifically, the pattern layer 3 consists of a plurality of spaced insulating units 31.

[0043] In this embodiment, as Figure 2 As shown, each insulating unit 31 specifically includes multiple insulating protrusions 32 arranged in a square, with the sides of the square parallel to the sides of the corresponding non-vibrating substrate layer 21 or vibrating substrate layer 11. The multiple insulating units 31 are arranged in an array to form multiple array units 33. This invention, by readjusting the pattern arrangement of the pattern layer 3 to be parallel to the sides of the vibrating substrate layer 11 or non-vibrating substrate layer 21, facilitates the printing of the pattern layer 3 and ensures uniform tension diffusion on the vibrating layer 1, thereby improving the reliability of the formed directional sound-emitting screen.

[0044] Furthermore, more preferably, the present invention provides a support point 34 at the center of each array unit 33. The support point 34 can be a single point or a multi-point structure, and the height of the support point 34 is less than the height of the insulating bump 32. In a specific embodiment, the height of the support point 34 is 2µm to 4µm, the height of the insulating bump 32 is 7µm to 12µm, and the spacing between two adjacent array units 33 (here, the spacing is the distance between the centers of two adjacent array units 33) is 2.2µm to 2.8µm. In another specific embodiment, the printhead used in the printing process of the pattern layer 3 is a Konica 1024 with a printhead width of 72mm and a nozzle diameter of 27µm. Figure 2As shown in the figure, the spacing L1 between two adjacent horizontal insulating units 31 is 3.4931 mm, the vertical height L2 of each insulating unit 31 is 141 μm, and the distance L3 from the center of the support point 34 to the center of the adjacent insulating unit 31 is 2.47 mm, which can ensure that the bonding area of ​​each insulating unit 31 is maximized. Alternatively, in implementation, the conductive layer (here, the conductive layer refers to the first conductive layer 12 and / or the second conductive layer 22) corresponding to the center of each array unit 33 can be removed (in implementation, etching or laser lamp process can be used to achieve this), forming a non-conductive layer part. In implementation, the non-conductive layer part can be a single solid circle or a hollow ring, and the non-conductive layer part can be a single point or a single cluster of multiple points. In reliability failure models, a high-probability failure model is as follows: the membrane material corresponding to the maximum amplitude experiences the greatest deformation due to prolonged vibration. As operating time increases, this location is the first to come into contact with the non-vibrating layer, leading to noise generation, increased distortion, and reliability failure. Furthermore, if the diaphragm completely contacts the substrate, the resulting indentation at the contact point can cause visual distortion, resulting in a regular or sheet-like collapse of the entire diaphragm. This invention, by setting a support point 34 at the center of each array unit 33 of the patterned layer, avoids this collapse phenomenon and suppresses the increased distortion caused by the collision between the vibrating layer 1 and the non-vibrating layer 2 at the maximum amplitude of each array unit 33, thus preventing reliability failure. Furthermore, by setting a non-conductive layer, the corresponding vibrating layer 1 is not subjected to electric field forces, reducing its size and preventing the phenomenon of contact failure between the vibrating layer 1 and the non-vibrating layer 2 at this location.

[0045] Furthermore, the pattern layer 3 is fixed to the insulating layer 23 or the first conductive layer 12 by an adhesive layer 6. In practice, the adhesive layer 6 is a structure of multiple spaced adhesive units corresponding to the structure of the pattern layer 3, or it is a whole surface. In a specific embodiment, the pattern layer 3 and the insulating layer 23 are fixed by adhesive points. Specifically, the adhesive points can be formed on the surface of the insulating layer 23 near the first conductive layer 12, and the positions of the adhesive points on the insulating layer 23 correspond to the positions of the pattern layer 3 on the vibrating substrate layer 11. That is, each adhesive point corresponds to an insulating protrusion 32, or each insulating protrusion 32 on the pattern layer 3 is provided with an adhesive point. The smaller the height of the adhesive point, the better, preferably 1µm to 2µm. This invention fixes the patterned layer 3 to the insulating layer 23 or the first conductive layer 12, so that after the non-vibrating layer 2 and the vibrating layer 1 are bonded together, they can form stable vibrating units. This prevents the vibrating layer 1 from detaching from the non-vibrating layer 2 during vertical vibration, thus eliminating the ineffective vibration distance of the vibrating layer 1. This not only reduces the sound distortion of the entire directional sound-emitting screen (in one specific embodiment, the design of the adhesive points can effectively reduce the total harmonic distortion (THD) at 1kHz from 20% to below 5%), but also reduces the driving power of the entire product and improves reliability. In implementation, the adhesive points can be formed by inkjet printing or dispensing processes, including high-precision 3D inkjet printing or non-3D inkjet printing. In other alternative embodiments, the patterned layer 3 can also be fixed to the insulating layer 23 or the first conductive layer 12 by an adhesive layer (not shown).

[0046] like Figure 3 As shown, this invention also discloses another manufacturing process for a directional sound-emitting screen, which mainly includes the following steps:

[0047] S1, Prepare the vibration layer 1, including making a first conductive layer 12 on the entire surface of the vibration substrate layer 11 near the non-vibration layer 2.

[0048] Specifically, in implementation, the vibrating substrate layer 11 can be a PET film. A first conductive layer 12 is formed on the surface of the PET film by magnetron sputtering. Then, full-surface wiring (the wiring material can be copper) is formed on the surface of the first conductive layer 12 by magnetron sputtering. Finally, the first edge wiring 13 is etched by exposure, development and etching.

[0049] S2, Prepare a non-vibrational layer 2, including making a second conductive layer 22 on the entire surface of the non-vibrational substrate layer 21 near the vibrational layer 1.

[0050] Specifically, in implementation, the non-vibrating substrate layer 21 can be glass. A second conductive layer 22 is formed on the glass surface by magnetron sputtering. Then, full-surface traces (the trace material can be copper) are formed on the surface of the second conductive layer 22 by magnetron sputtering. Finally, the second edge traces 24 are etched by exposure, development and etching.

[0051] S3, a pattern design is printed on the surface of the first conductive layer 12 near the non-vibrating layer 2 or on the surface of the second conductive layer 22 near the vibrating layer 1 to form a pattern layer 3.

[0052] Specifically, in practice, a pattern layer 3 can be printed on the surface of the insulating layer 23 or the first conductive layer 12, and then an adhesive layer 6 can be printed on the pattern layer 3.

[0053] S4, an ink layer doped with antistatic microspheres 4 is screen-printed on the surface of the second conductive layer 22 near the vibrating layer 1 or on the surface of the first conductive layer 12 near the non-vibrating layer 2 to form an insulating layer 23. The insulating layer 23 covers the pattern layer 3 or directly covers the corresponding conductive layer.

[0054] Specifically, an insulating layer 23 is screen-printed on the second conductive layer 22 or the entire surface of the first conductive layer 12. After screen printing, the insulating layer 23 is UV-cured or heat-cured. After curing, the non-vibrating layer 2 is bonded to the vibrating layer 1. Bonding requires tensioning the vibrating layer 1 and applying direct current to ensure that the vibrating layer 1 and the non-vibrating layer 2 have Coulomb attraction. At the same time, the adhesive layer 6 in the UV-cured surface fully ensures that the vibrating layer 1 and the non-vibrating layer 2 are firmly bonded together.

[0055] In one specific embodiment, the thickness of the vibrating substrate layer 11 is 100um to 125um, the thickness of the waterproof layer 5 is 1um to 10um, the thickness of the adhesive layer 6 is 1um to 2um, the height of the insulating bumps 32 of the pattern layer 3 is 7um to 12um, and the spacing between the array units 33 of the pattern layer 3 is 2.2mm to 2.8mm.

[0056] The advantages of this invention are as follows: 1. By doping the ink insulating medium of the directional sound-emitting screen with antistatic microspheres, this invention improves the stability of the ink insulating medium, making it less prone to losing charge and reducing the accumulation of static electricity on its surface, thereby greatly reducing the impact of air ionization charge on air partial pressure. 2. By readjusting the pattern arrangement and spacing of the pattern layer, this invention facilitates the printing of the pattern layer and increases the bonding area between the pattern layer and the vibrating or non-vibrating layer, making the vibrating and non-vibrating layers more stable and ensuring uniform tension diffusion on the vibrating layer, which is beneficial to improving the reliability of the formed directional sound-emitting screen. 3. By setting a support point or a non-conductive layer at the center of each array unit of the pattern layer, this invention can suppress the increased distortion caused by the collision between the vibrating layer and the non-vibrating layer at the maximum amplitude of each array unit, thus preventing reliability failure.

[0057] The foregoing description of specific exemplary embodiments of the invention is for illustrative and explanatory purposes. These descriptions are not intended to limit the invention to the precise forms disclosed, and it will be apparent that many changes and variations can be made in accordance with the foregoing teachings. The exemplary embodiments were chosen and described in order to explain the specific principles of the invention and its practical application, thereby enabling those skilled in the art to implement and utilize various different exemplary embodiments of the invention, as well as various different choices and variations. The scope of the invention is intended to be defined by the claims and their equivalents.

Claims

1. A directional sound emitting screen, characterized in that, The directional sound screen comprises: a vibration layer, which comprises a vibration substrate layer and a first conductive layer formed on the surface of the vibration substrate layer close to the non-vibration layer; a non-vibration layer, which is in contact with the frame of the vibration layer, and comprises a non-vibration substrate layer and a second conductive layer formed on the surface of the non-vibration substrate layer close to the vibration layer; a pattern layer, which is located between the first conductive layer and the second conductive layer, and forms an air gap required for the vibration layer to vibrate and sound between the vibration layer and the non-vibration layer after the vibration layer is in contact with the frame of the non-vibration layer, and the pattern layer comprises a plurality of insulating units arranged at intervals; an insulating layer, which is located between the pattern layer and the first conductive layer or between the pattern layer and the second conductive layer, and is an ink layer doped with anti-static microspheres.

2. A directional sound emitting screen as claimed in claim 1, characterized in that The anti-static microspheres comprise any one of silica spherical powder, polytetrafluoroethylene spherical powder, acrylic copolymer spherical powder and organic compound spherical powder.

3. A directional sound emitting screen according to claim 1 or 2, characterized in that The diameter of the anti-static microspheres is 0.2um-20um, and the total amount of the anti-static microspheres is 0.5%-30% of the total amount of the ink layer before the anti-static microspheres are doped and after the moisture is removed.

4. A directional sound emitting screen as claimed in claim 1, characterized in that The insulating layer is formed on the surface of the second conductive layer close to the vibration layer or on the surface of the first conductive layer close to the non-vibration layer by a silk screen printing process.

5. A directional sound emitting screen as claimed in claim 1, characterized in that Each of the insulating units comprises a plurality of insulating protrusions arranged in a square shape and having edges parallel to the edges of the corresponding non-vibration substrate layer or vibration substrate layer, and a plurality of the insulating units are arranged in an array to form a plurality of array units.

6. A directional sound emitting screen as claimed in claim 5, characterized in that A support point is arranged at the center of each of the array units, the support point is a single-point or multi-point structure, and the height of the support point is less than the height of the insulating protrusion; or the corresponding conductive layer at the center of each of the array units is removed to form a non-conductive layer part.

7. A directional sound emitting screen as claimed in claim 6, characterized in that The height of the support point is 2um-4um, the height of the insulating protrusion is 7um-12um, and the spacing between adjacent two array units is 2.2um-2.8um.

8. A directional sound emitting screen as claimed in claim 1 or 5, characterized in that The pattern layer and the insulating layer are fixed by an adhesive layer, which is a plurality of adhesive unit structures arranged at intervals corresponding to the structure of the pattern layer or is in a full-surface shape.

9. A directional sound emitting screen as defined in claim 1, wherein, A waterproof layer is further arranged on the outermost surface of the vibration layer away from the non-vibration layer, and the thickness of the waterproof layer is 1um-10um.

10. A process for the preparation of a directional sound emitting screen, characterized in that, The directional sound screen is the directional sound screen according to any one of claims 1-9, and the preparation process comprises: S1, preparing a vibration layer, which comprises forming a first conductive layer on the surface of a vibration substrate layer close to a non-vibration layer; S2, preparing a non-vibration layer, which comprises forming a second conductive layer on the surface of a non-vibration substrate layer close to the vibration layer; S3, forming a pattern layer on the surface of the first conductive layer close to the non-vibration layer or on the surface of the insulating layer close to the vibration layer. S4, forming an ink layer doped with anti-static microspheres on the surface of the second conductive layer close to the vibration layer or on the surface of the first conductive layer close to the non-vibration layer as an insulating layer, which covers the pattern layer or directly covers the corresponding conductive layer in full.

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