A manufacturing method for stamping insulating bumps on a directional sound-emitting screen

Abstract

The present invention discloses a method for imprinting insulating bumps on a directional sound emission screen, belonging to the technical field of touch display, which comprises the following steps: S1. providing a printing substrate (4); S2. imprinting a second insulating layer (20) on the surface of the first insulating layer (2) of the printing substrate (4); S3. exposing the second insulating layer (20) according to an exposure pattern; S4. developing the exposed second insulating layer (20) to form insulating bumps (5) on the first insulating layer (2). By imprinting the second insulating layer and then exposing and developing, the present invention can conveniently fabricate insulating bumps on the printing substrate, so that a highly transparent electrostatic ultrasonic transducer and a directional sound emission screen can be conveniently fabricated subsequently. At the same time, the product prepared by this method has good stability and high breakdown voltage resistance.

Description

Technical Field

[0001] The present invention relates to the technical field of touch display, and particularly to a method for fabricating insulating bumps on a directional sound-emitting screen by imprinting. Background Art

[0002] With the development of the ultra-thin, narrow bezel, and even full-screen design of display devices, the space left for the sound-emitting device in the display device is getting smaller and smaller. Since the volume of a typical sound-emitting device (such as a speaker) is usually relatively large and mostly based on a silicon-based MEMS (Micro-Electro-Mechanical System) process structure, it is difficult to achieve an integrated design with the display panel. In addition, for some special requirements, people may more hope that the display device can have a sound-emitting device with directional sound emission, and the sound-emitting device with directional sound emission can be integrated with the display panel, so as to combine directional sound emission with display technology.

[0003] Currently, a directional sound-emitting screen usually includes an electrostatic ultrasonic transducer, and directional sound emission is achieved through the electrostatic ultrasonic transducer. The electrostatic ultrasonic transducer refers to "a transducer that uses an electric field force to vibrate a diaphragm to emit ultrasonic waves", and is a new type of ultrasonic sound emitter. Since the positive and negative electrodes of the electrostatic ultrasonic transducer face each other, it is also called a capacitive transducer. The electrostatic ultrasonic transducer often includes two upper and lower transparent conductive sheets and an insulating layer disposed between the two transparent conductive sheets. In order to provide a vibration space, insulating bumps need to be provided on the insulating layer. How to fabricate insulating bumps with high transparency, required patterns, and thickness is a problem that needs to be solved currently.

[0004] Therefore, it is necessary to improve the existing technology to overcome the defects in the existing technology. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for fabricating insulating bumps on a directional sound-emitting screen by imprinting, which can conveniently fabricate insulating bumps on the insulating layer.

[0006] To achieve the above-mentioned invention purpose, the present invention provides a method for fabricating insulating bumps on a directional sound-emitting screen by imprinting, including the following steps:

[0007] S1. Provide a printing substrate;

[0008] S2. Imprint a second insulating layer on the surface of the first insulating layer of the printing substrate;

[0009] S3. Expose the second insulating layer according to an exposure pattern;

[0010] S4. Develop the exposed second insulating layer to form insulating bumps on the first insulating layer.

[0011] Further, the step S2 includes the following steps:

[0012] S21. Install the insulating photosensitive film on the film laminating device, with one side of the insulating photosensitive film in contact with the film laminating roller;

[0013] S22. Install the printing substrate on the film laminating device, with the printing substrate corresponding to the position of the film laminating roller of the film laminating device;

[0014] S23. Drive the film laminating roller to rotate, press the insulating photosensitive film onto the first insulating layer, and form the second insulating layer on the surface of the printing substrate.

[0015] Further, when pressing the insulating photosensitive film onto the first insulating layer, the temperature range of the film laminating roller is 100 - 130 °C, and the humidity range of the film laminating roller is 5% - 30%.

[0016] Further, in the step S4, when developing the exposed second insulating layer, the developer used includes a sodium carbonate solution with a concentration of 0.1% - 2%, the duration of the second insulating layer passing through the developer is 10 - 60 s, and the temperature range during development is 20 - 40 °C.

[0017] Further, the step S1 includes the following steps:

[0018] S11. Print a conductive paste layer on the base layer;

[0019] S12. Attach a conductive layer on the conductive paste layer;

[0020] S13. Set a third insulating layer on the conductive layer;

[0021] S14. Cure the third insulating layer, and the base layer, conductive paste layer, conductive layer, and third insulating layer form a conductive substrate;

[0022] S15. Produce a first insulating layer on the surface of the conductive substrate.

[0023] Further, in the step S15, the first insulating layer is produced on the surface of the conductive substrate by means of screen printing.

[0024] Further, the step S15 includes the following steps:

[0025] S151. Install the conductive substrate on the screen printing machine table, with the conductive substrate located below the screen of the screen printing machine table;

[0026] S152. Print the insulating material through the screen onto the conductive substrate to form the first insulating layer on the surface of the conductive substrate;

[0027] S153. Cure the first insulating layer.

[0028] Further, the step S1 includes the following steps:

[0029] S11. Fabricate a first insulating layer on the surface of the base layer, with a first space reserved at the edge of the first insulating layer and the base layer;

[0030] S12. Cure the first insulating layer.

[0031] Further, the step S11 includes the following steps:

[0032] S111. Install the base layer on the screen printing machine table, with the base layer located below the screen of the screen printing machine table;

[0033] S112. Print the insulating material onto the base layer through the screen to form the first insulating layer on the surface of the base layer, with a first space reserved at the edge of the first insulating layer and the base layer.

[0034] Further, the method for fabricating the insulating bumps of the directional sound screen further includes the following steps after the step S4:

[0035] S50. Print a conductive paste layer on the surface of the base layer corresponding to the first space;

[0036] S51. Attach a conductive layer to the conductive paste layer;

[0037] S52. Set a third insulating layer on the conductive layer;

[0038] S53. Cure the third insulating layer.

[0039] Further, the thickness range of the conductive layer is 8 - 10 μm, and the thickness range of the third insulating layer is 8 - 10 μm.

[0040] Further, the following steps are also included between the step S1 and the step S2:

[0041] Detect the dyne value of the first insulating layer. If the dyne value is lower than the first preset value, perform plasma treatment on the surface of the first insulating layer.

[0042] Compared with the prior art, the present invention has the following beneficial effects: In the method for imprinting insulating bumps on a directional sound emission screen of the present invention, insulating bumps can be conveniently fabricated on a printing substrate by imprinting a second insulating layer followed by exposure and development. Subsequently, it becomes convenient to fabricate a highly transparent electrostatic ultrasonic transducer and a directional sound emission screen using these bumps. Meanwhile, the products prepared by this method exhibit good stability and high breakdown voltage resistance. For the first insulating layer with a thickness of 8 - 11 microns, the maximum breakdown voltage can reach 1200V. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 is a flowchart of the method for imprinting insulating bumps on a directional sound emission screen of the present invention.

[0044] Figure 2 is a cross-sectional view of the printing substrate in the present invention.

[0045] Figure 3 is a schematic diagram of the printing substrate with a second insulating layer in the present invention.

[0046] Figure 4 is a schematic diagram of the printing substrate with insulating bumps in the present invention.

[0047] Figure 5 is a flowchart of step S2 in the present invention.

[0048] Figure 6 is a schematic diagram when a laminating device imprints on a printing substrate in the present invention.

[0049] Figure 7 is a flowchart of step S23 in the present invention.

[0050] Figure 8 is a schematic diagram of a sub-insulating layer stacked on the first insulating layer in the present invention.

[0051] Figure 9 is a schematic diagram of a film with an exposure pattern in the present invention.

[0052] Figure 10 is a flowchart of step S3 in the present invention.

[0053] Figure 11 is a schematic diagram of the connection between a conductive member and a base layer in the present invention

[0054] Figure 12 is a schematic diagram of the structure of a conductive substrate in the present invention.

[0055] Figure 13 is a flowchart of step S1 in the first embodiment of the present invention.

[0056] Figure 14 is a flowchart of step S15 in the first embodiment of the present invention.

[0057] Figure 15 It is the flowchart of step S1 in the second embodiment of the present invention.

[0058] Figure 16 It is the flowchart of step S11 in the second embodiment of the present invention.

[0059] Figure 17 It is the schematic diagram of the product formed after step S1 in the second embodiment of the present invention.

[0060] Figure 18 It is the flowchart of step S5 in the second embodiment of the present invention.

[0061] Figure 19 It is the schematic diagram of the product formed after step S5 in the second embodiment of the present invention. Detailed implementation manners

[0062] To make the above objects, features, and advantages of the present application more obvious and understandable, the following will describe the detailed implementation manners of the present application in conjunction with the accompanying drawings. It can be understood that the specific embodiments described herein are only used to explain the present application, rather than limiting the present application. Additionally, it should be noted that for the sake of convenience of description, only the parts related to the present application rather than all the structures are shown in the drawings. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present application.

[0063] The terms "including" and "having" in the present application and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but optionally further includes steps or units not listed, or optionally further includes other steps or units inherent to these processes, methods, products, or devices.

[0064] Referring to "embodiment" in this context means that the specific features, structures, or characteristics described in connection with the embodiment can be included in at least one embodiment of the present application. The phrase appearing at various positions in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0065] As Figures 1 to 4 shown, corresponding to the method for fabricating an insulating bump imprint of a directional sound emission screen in a preferred embodiment of the present invention, it includes the following steps:

[0066] S1. Provide a printing substrate 4, refer to Figure 2 ;

[0067] S2. Stamp the second insulating layer 20 on the surface of the first insulating layer 2 of the printing substrate 4, refer to Figure 3 ;

[0068] S3. Expose the second insulating layer 20 according to the exposure pattern;

[0069] S4. Develop the exposed second insulating layer 20 to form insulating bumps 5 on the first insulating layer 2, refer to Figure 4 。

[0070] The printing substrate 4 includes a base layer 10 and a first insulating layer 2 provided on the surface of the base layer 10. The base layer 10 of the printing substrate 4 is made of a transparent material. As a preferred embodiment, the base layer 10 is made of ITO conductive glass, which can be used as a display screen or a part of a display screen, or used in combination with a display screen without affecting the display of the display screen. Similarly, both the first insulating layer 2 and the second insulating layer 20 are made of transparent materials.

[0071] The above step S2 can be carried out by a laminating device. Specifically, as Figure 5 shown, step S2 includes the following steps:

[0072] S21. Install the insulating photosensitive film 62 on the laminating device, and one side of the insulating photosensitive film 62 is in contact with the laminating roller;

[0073] S22. Install the printing substrate 4 on the laminating device, and the printing substrate 4 corresponds to the position of the laminating roller of the laminating device;

[0074] S23. Drive the laminating roller to rotate, press the insulating photosensitive film 62 onto the first insulating layer 2, and form the second insulating layer 20 on the surface of the printing substrate 4.

[0075] As a preferred embodiment, as Figure 6As shown, the laminating device has a feeding roller 6, and an upper laminating roller 60 and a lower laminating roller 61 which are arranged relatively parallel. An insulating photosensitive film 62 is installed on the feeding roller 6 in the form of a roll, which includes a release film layer and an insulating photosensitive film layer. The feeding roller 6 can be driven by a motor to rotate and discharge. The upper laminating roller 60 and the lower laminating roller 61 can realize synchronous rotation through a transmission mechanism such as a gear transmission. A stamping position for placing a substrate 4 is formed between the upper laminating roller 60 and the lower laminating roller 61. During stamping, the substrate 4 is placed at the stamping position of the laminating device for stamping. The conductive substrate 1 is placed between the upper laminating roller 60 and the lower laminating roller 61. The rotation directions of the two laminating rollers are exactly opposite, for example, the upper laminating roller 60 rotates clockwise, and the lower laminating roller 61 rotates counterclockwise, so that when driven to rotate by a motor, the conductive substrate 1 can be driven to move in the same direction. The insulating photosensitive film 6 is led out to the upper film pressing roller 60 through a number of tensioning wheels or guide wheels, and its release film layer is in contact with the upper film pressing roller 60, and the insulating photosensitive film layer is in contact with the first surface of the printing substrate 4 (the first surface is the surface of its first insulating layer 2 away from the base layer 10). When the two film pressing rollers rotate, the insulating photosensitive film layer is pressed onto the entire first surface of the printing substrate 4 to form a second insulating layer 20, and the release film layer is separated from the insulating photosensitive film layer and is wound onto the receiving roller 63.

[0076] In order to ensure that the stamping work is carried out efficiently and reliably, during the stamping process, the temperature range of the stamping roller is 100-130°C, and the humidity range of the stamping roller is 5%-30%. In this way, the insulating photosensitive film 62 is transferred to the printing substrate 4 with higher efficiency and better quality.

[0077] The thickness of the insulating bump 5 is preferably 1 to 60 μm. Within this thickness range, when it is integrated with the display screen, it is not visible on the display screen. More preferably, the thickness of the insulating bump 5 is 1 to 50 μm. More preferably, the thickness of the insulating bump 5 is 1 to 40 μm. The thickness of the insulating bump 5 is consistent with the thickness of the second insulating layer 20, which can be ensured by the thickness of the insulating photosensitive film 62 and the number of stamping times. When a thicker second insulating layer 20 needs to be formed, the second insulating layer 20 can be thickened by multiple stampings as appropriate. Specifically, when multiple stampings are used, Figure 7 and Figure 8 As shown, the above step S23 may include the following steps:

[0078] S231. Drive the lamination roller to rotate, press the insulating photosensitive film 62 onto the printing substrate 4, and superimpose a sub-insulating layer 21 having a thickness less than the second insulating layer 20 on the surface of the printing substrate 4;

[0079] S232. The printing substrate 4 with the sub-insulating layer 21 is left to stand for a preset time;

[0080] S233. Repeat steps S22, S231, and S232 until the total thickness of the multi-layer sub-insulating layer 21 reaches within the thickness error range of the second insulating layer 20.

[0081] In step S232, the preset standing time is not limited, and it is advisable to restore the overall temperature of the printing substrate 4 and the sub-insulating layer 21 to room temperature. Preferably, the preset time is more than 15 minutes. In this way, the size of the sub-insulating layer 21 can be basically fixed, ensuring the stability of the size change of the second insulating layer 20 when the sub-insulating layer 21 is subsequently stacked.

[0082] In step S233, the printing substrate 4 with the sub-insulating layer 21 stacked thereon can be repeatedly placed at the laminating roller for embossing, or multiple groups of laminating rollers can be set up, and the printing substrate 4 can continuously pass through multiple groups of laminating rollers. Each group of laminating rollers can emboss a layer of sub-insulating layer 21 on the printing substrate 4, which has a higher degree of automation and is more convenient to use.

[0083] It can be understood that referring to Figure 8 , each time of embossing can increase the thickness of the second insulating layer 20 located on the printing substrate 4. In this embodiment, by the method of standing and then embossing, the thickness of the current second insulating layer 20 after each curing can be accurately controlled, thereby improving the dimensional accuracy of the second insulating layer 20 after molding. Correspondingly, the dimensional accuracy of the insulating bumps obtained after subsequent exposure and development is also higher.

[0084] Further preferably, after each standing of the sub-insulating layer 21, the thickness of the second insulating layer 20 formed on the printing substrate 4 is measured to facilitate adjusting the increase amount of the thickness of the second insulating layer 20 later (for example, the insulating photosensitive film 62 with different thicknesses can be replaced), so as to obtain a second insulating layer 20 with higher dimensional accuracy. The thickness of the second insulating layer 20 is preferably measured using an optical contact type scraping thickness test instrument.

[0085] The exposure pattern in step S3 is set according to parameters such as the size and position of the insulating bumps 5 to be formed as required. The exposure pattern is set on a carrier. As a preferred embodiment, the carrier is preferably a film. Figure 9 Fig. shows a film 7 with an exposure pattern. The film 7 includes a light-shielding portion 70 and a plurality of light-transmitting portions 71 provided on the light-shielding portion 70. The light-transmitting portions 71 can be through holes or regions made of transparent materials, and they correspond to the size and position of the insulating bumps 5. During exposure, the portion of the second insulating layer 20 corresponding to the light-transmitting portions 71 is exposed, while the portion corresponding to the light-shielding portion 70 is not exposed. During subsequent development, the unexposed portion is removed, thereby forming the insulating bumps 5. Thus, referring to Figure 10 , step S3 can specifically include the following steps:

[0086] S31. Cover the carrier with the exposure pattern onto the surface of the second insulating layer 20;

[0087] S32. Expose the second insulating layer 20 covered with the carrier.

[0088] In the above step S3, the second insulating layer 20 can be exposed by an LDI or an LED exposure machine. It can be understood that the more complete the exposure, the firmer the exposed material during subsequent development, the less likely it is to be removed by the developer, and the better the quality of the second insulating layer 20. Therefore, it is necessary to ensure the completeness of its exposure. As a preferred embodiment, the exposure wavelength range is 365 nm to 400 nm.

[0089] In step S4, the development quality can be controlled by controlling factors such as the parameters of the developer, the development duration, and the development temperature. As a preferred embodiment, the developer includes a sodium carbonate solution. The concentration of the sodium carbonate solution is preferably 0.1% to 2%, more preferably 0.8 to 1.5%, with a central value of 1.1%. The duration for the second insulating layer 20 to pass through the developer is controlled within 10 to 60 s, with a central value of 35 s. The temperature range during development is between 20 and 40 °C. Among them, the duration for the second insulating layer 20 to pass through the developer can also be adjusted according to the liquid discharge mode of the developer in the developing equipment. For example, the corresponding times for fan-shaped liquid discharge and circular liquid discharge are different.

[0090] In addition, during the development process of step S4, the rollers of the developing machine for transporting the printing substrate 4 only include the transport rollers supported below the printing substrate 4, and the printing substrate 4 is transported by the transport rollers. The reason is that in the existing developing machine with upper and lower roller design, the second insulating layer 20 will be blocked by the upper roller, resulting in uneven development; so to achieve uniform development, high requirements are imposed on conditions such as the liquid discharge mode. In this embodiment, only the transport rollers supported below the printing substrate 4 are provided, so there is no upper roller blocking above the second insulating layer 20, and its development effect is better.

[0091] As a preferred embodiment, the method for fabricating the insulating bumps of the directional sound screen of the present invention further includes a curing step after step S4: curing the insulating bumps 5. Preferably, curing is carried out by raising the temperature. The curing temperature range is 100 °C to 200 °C, and the curing time range is 20 to 80 min. In this way, the insulating bumps 5 can be quickly cured to prevent contamination such as dust from adhering due to too long a time.

[0092] As a preferred embodiment, the method for fabricating the insulating layer of the directional sound screen further includes an inspection step after step S5: inspecting the thickness of the insulating bumps 5.

[0093] The thickness of the insulating bump 5 can be measured using an optical contact scraping thickness testing instrument to facilitate determining whether the thickness of the insulating bump 5 is within the error range.

[0094] As Figure 11 and Figure 12 shown, it is usually also necessary to provide a conductive member 3 on the base layer 10 for power-on. The conductive member 3 includes a conductive layer 11, a conductive paste layer 12 connected between the base layer 10 and the conductive layer 11, and a third insulating layer 13 connected to the conductive layer 11.

[0095] The conductive layer 11 is preferably a metal conductive layer, for example, it can be a copper foil. The conductive layer 11 and the substrate 1 are connected through the conductive paste layer 12. The conductive paste layer 12 is preferably a silver paste layer, which has good conductivity. The third insulating layer 13 is provided on the outer surface of the conductive layer 11, and the third insulating layer 13 and the conductive paste layer 12 are located on both sides of the conductive layer 11 respectively.

[0096] As a preferred implementation manner, the conductive member 3 is connected to the edge or near the edge of the base layer 10 to avoid or reduce the obstruction of the conductive member 3 to the display area of the display screen. In this embodiment, the conductive member 3 is in a ring shape arranged along the outer edge of the base layer 10. In order to avoid the obstruction of the conductive layer 11 to the display area of the display screen, the base layer 10 can also be divided into a first area corresponding to the display area of the display screen and a second area located outside the first area, and the conductive layer 11 is provided in the second area.

[0097] As a preferred implementation manner, in step S1, the printing substrate 4 can be provided by preparing the printing substrate 4.

[0098] In the first embodiment, as Figure 13 shown, step S1 includes the following steps:

[0099] S11. Print the conductive paste layer 12 on the base layer 10;

[0100] S12. Attach the conductive layer 11 on the conductive paste layer 12;

[0101] S13. Set the third insulating layer 13 on the conductive layer 11;

[0102] S14. Cure the third insulating layer 13, and the base layer 10, the conductive paste layer 12, the conductive layer 11 and the third insulating layer 13 form a conductive substrate 1;

[0103] S15. Make the first insulating layer 2 on the surface of the conductive substrate 1.

[0104] In the above step S13, the third insulating layer 13 can be set on the conductive layer 11 by means of screen printing, imprinting or spraying, etc. The material of the third insulating layer 13 is preferably the same as that of the first insulating layer 2.

[0105] In the first embodiment, the conductive member 3 is disposed on the base layer 10 before the first insulating layer 2 is formed. Therefore, in the subsequent step S15, the first insulating layer 2 can cover the surfaces of the base layer 10 and the conductive member 3, which greatly improves the breakdown voltage resistance at the conductive member 3.

[0106] In the first embodiment, the width of the insulating photosensitive film 62 is the same as the width of the second insulating layer 20, so that when laminating the film, the insulating photosensitive film 62 can be embossed to form the second insulating layer 20 without additional trimming. A high-precision movable platform can be used as the material placement platform or other high-precision positioning devices can be used to ensure the position accuracy of the insulating photosensitive film 62 when embossing on the printing substrate 4.

[0107] As a preferred implementation manner, before step S11, there is also a step of cleaning the base layer 10. Between steps S14 and S15, there is also a step of cleaning the conductive substrate 1. The base layer 10 and the conductive substrate 1 can be cleaned by water washing to remove particulate matter and dust on the surfaces of the base layer 10 and the conductive substrate 1. In this way, the through-holes after forming the second insulating layer 20 can be reduced or even eliminated, and the subsequent processing quality is better. When cleaning, an ordinary water washing line in the touch field can be used for water washing. As a preferred implementation manner, the roller group of the water washing line for transporting the conductive substrate 1 only has lower rollers supported under the conductive substrate 1 and no upper rollers to prevent scratching of the surface of the conductive substrate 1 (ITO conductive glass). The water washing time is not limited and can be determined according to the water pressure and the overall line speed, as long as the appearance inspection of the outgoing material meets the appearance standard.

[0108] In step S15, the first insulating layer 2 can be formed on the surface of the conductive substrate 1 by means of screen printing, embossing or spraying, etc. The thickness of the first insulating layer 2 is preferably 1-20 μm, and more preferably 8-11 μm. Taking screen printing as an example, as Figure 14 shown, step S15 includes the following steps:

[0109] S151. Install the conductive substrate 1 on the screen printing machine table, and the conductive substrate 1 is located below the screen of the screen printing machine table;

[0110] S152. Print the insulating material onto the conductive substrate 1 through the screen to form the first insulating layer 2 on the surface of the conductive substrate 1;

[0111] S153. Cure the first insulating layer 2. The state of the product formed at this time refers to Figure 2 .

[0112] In step S152, the insulating material is preferably a quick-drying insulating ink. The insulating material includes materials such as polyester, epoxy resin, and acrylic, etc. Its curing time is short, which can prevent the accumulation of particulate matters such as dust on the surface of the ink due to the long curing time. As a preferred implementation, the insulating ink with a thickness of 1 - 50 μm can be completely cured within 20 minutes under the temperature condition of 60 - 200 °C.

[0113] In the above step S153, the first insulating layer 2 can be cured by baking / UV curing.

[0114] In the second embodiment, as Figures 15 to 17 shown, step S1 includes the following steps:

[0115] S11. Fabricate a first insulating layer 2 on the surface of the base layer 10, and a first space 100 is reserved between the first insulating layer (2) and the edge of the base layer 10;

[0116] S12. Cure the first insulating layer 2.

[0117] Similarly, in step S11, the first insulating layer 2 can be fabricated on the surface of the base layer 10 by means of screen printing, embossing, or spraying, etc. The thickness of the first insulating layer 2 is preferably 1 - 20 μm, and more preferably 8 - 11 μm. Taking screen printing as an example, as Figure 16 shown, step S11 includes the following steps:

[0118] S111. Install the base layer 10 on the screen printing machine table, and the base layer 10 is located below the screen of the screen printing machine table;

[0119] S112. Print the insulating material onto the base layer 10 through the screen to form the first insulating layer 2 on the surface of the base layer 10, and a first space 100 is reserved between the first insulating layer 2 and the edge of the base layer 10.

[0120] Before the above step S11, there is also a step of cleaning the base layer 10. The base layer 10 can also be cleaned by the above-mentioned water washing line, which can improve the subsequent printing quality.

[0121] The insulating material in the above step S112 is preferably the same quick-drying insulating ink as that in the first embodiment.

[0122] In the above step S11, the reserved first space 100 is used for installing the conductive part 3, and the conductive part 3 is arranged on the base layer 10 after the subsequent step S4. As Figure 18 shown, after step S4, there is step S5. Set the conductive part 3 in the first space 100. Specifically, step S5 includes the following steps:

[0123] S50. Print a conductive paste layer 12 on the surface of the base layer 10 corresponding to the first space 100;

[0124] S51. Attach a conductive layer 11 to the conductive paste layer 12;

[0125] S52. Provide a third insulating layer 13 on the conductive layer 11, and the base layer 10, the conductive paste layer 12, the conductive layer 11, and the third insulating layer 13 form a conductive matrix 1;

[0126] S53. Cure the third insulating layer 13. The state of the product formed at this time is for reference Figure 19 .

[0127] In step S52, the third insulating layer 13 can be formed on the conductive layer 11 by, for example, screen printing. The width B of the first space 100 is set to be 1 mm or more to ensure that the third insulating layer 13 can be filled in the first space 100 during screen printing. Further preferably, the width B of the first space 100 is set to be 2 mm or more. In addition, the thickness of the conductive layer 11 and the thickness of the third insulating layer 13 need to be matched: the thickness range of the conductive layer 11 is generally 8 - 10 μm, and the thickness range of the third insulating layer 13 is also 8 - 10 μm (the third insulating layer 13 selects a material with low viscosity and high leveling property), which can ensure that the conductive layer 11 can be covered by the third insulating layer 13 and will not be broken down by a certain voltage.

[0128] It can be understood that since the product needs to be developed with a developer in step S4, the developer usually includes sodium carbonate and sodium hydroxide solutions, and the concentration varies according to the type of developer. Therefore, the first insulating layer 2 needs to be made of a material resistant to sodium carbonate and sodium hydroxide, and can resist the corrosion of the developer with the corresponding concentration to ensure the quality of the finally obtained product.

[0129] In order to ensure the firmness of the connection between the insulating bump 5 and the first insulating layer 2, the following steps are further included between step S1 and step S2:

[0130] Detect the dyne value of the first insulating layer 2. If the dyne value is lower than the first preset value, perform plasma treatment on the surface of the first insulating layer 2; if the dyne value is above the second preset value, do not perform plasma treatment.

[0131] Preferably, the first preset value is 38 and the second preset value is 40.

[0132] The dyne value of the first insulating layer 2 can be detected by a dyne pen, and the criterion for judgment is that there is no shrinkage in 3 - 5 s. Generally, in order to make the connection between the insulating bump 5 and the first insulating layer 2 more firm, the surface energy of the first insulating layer 2 is required to be high and the water contact angle is required to be low. If the surface energy is too low, the material of the first insulating layer 2 is likely to fall off to varying degrees during the subsequent development process. Therefore, plasma treatment of the first insulating layer 2 with a dyne value lower than 38 can effectively improve its surface energy, ensure the firmness of the connection between the insulating bump 5 and the first insulating layer 2, and prevent the material of the first insulating layer 2 from falling off during subsequent development. Preferably, the adhesion between the material of the insulating bump 5 and the material of the first insulating layer 2 can reach 5B.

[0133] During plasma treatment, there is no requirement for the principle of the plasma machine tool. The machine tool energy parameters and the number of treatments can be determined according to the results after treatment, as long as the reduction in the thickness of the first insulating layer 2 after treatment is less than 1 μm and the dyne value is not lower than 40.

[0134] The method for fabricating insulating bumps by imprinting for the directional sound emission screen of the present invention can conveniently fabricate insulating bumps on the printing substrate by imprinting the second insulating layer and then exposing and developing, so that a highly transparent electrostatic ultrasonic transducer and a directional sound emission screen can be conveniently fabricated subsequently. At the same time, the product prepared by this method has good stability and a high breakdown voltage resistance. The breakdown voltage resistance of the first insulating layer with a thickness of 8 - 11 μm can reach a maximum of 1200V.

[0135] The above is only a specific embodiment of the present invention, and any improvement made on the premise of the concept of the present invention is regarded as the protection scope of the present invention.

Claims

1. A method for fabricating insulating bumps of a directional sound-emitting screen by stamping, characterized in that It includes the following steps: S1. Provide a printing substrate (4), the printing substrate (4) includes a conductive substrate (1) and a first insulating layer (2), the conductive substrate (1) is formed by a base layer (10), a conductive paste layer (12), a conductive layer (11) and a third insulating layer (13), the conductive paste layer (12) is printed on the edge of the base layer (10), the conductive layer (11) is attached to the conductive paste layer (12), the third insulating layer (13) is disposed on the conductive layer (11), the first insulating layer (2) is provided on the surface of the conductive substrate (1), and the thickness of the first insulating layer (2) is 8-11 μm; S2. Imprint a second insulating layer (20) on the surface of the first insulating layer (2) of the printing substrate (4), the second insulating layer (20) is an insulating photosensitive film, and step S2 is performed by a laminating device. The laminating device includes a laminating roller. During the imprinting process, the temperature range of the laminating roller is 100-130 °C, and the humidity range is 5%-30%; S3. Expose the second insulating layer (20) according to an exposure pattern, the exposure pattern is provided on a carrier, the carrier includes a light-shielding portion (70) and a plurality of light-transmitting portions (71) provided on the light-shielding portion (70), the light-transmitting portions (71) are through holes, and their sizes and positions correspond to those of the insulating bumps (5). During exposure, the portion of the second insulating layer (20) corresponding to the light-transmitting portion (71) is exposed, while the portion corresponding to the light-shielding portion (70) is not exposed; S4. Develop the exposed second insulating layer (20), and the unexposed portion of the second insulating layer (20) is removed to form insulating bumps (5) on the first insulating layer (2).

2. The method for fabricating an insulating bump imprint of a directional sound-emitting screen according to claim 1, characterized in that The step S2 includes the following steps: S21. Install the insulating photosensitive film (62) on the laminating device, and one side of the insulating photosensitive film (62) is in contact with the laminating roller; S22. Install the printing substrate (4) on the laminating device, and the printing substrate (4) corresponds to the position of the laminating roller of the laminating device; S23. Drive the laminating roller to rotate, and imprint the insulating photosensitive film (62) onto the first insulating layer (2) to form the second insulating layer (20) on the surface of the printing substrate (4).

3. The method for fabricating an insulating bump imprint of a directional sound-emitting screen according to claim 1, wherein In the step S4, when developing the exposed second insulating layer (20), the developing solution used includes a sodium carbonate solution with a concentration of 0.1%-2%, the duration of the second insulating layer (20) passing through the developing solution is 10-60 s, and the temperature range during development is 20-40 °C.

4. The method for fabricating an insulating bump imprint of a directional sound-emitting screen according to any one of claims 1 to 3, characterized in that, The step S1 includes the following steps: S11. Print a conductive paste layer (12) on the edge of the base layer (10); S12. Attach a conductive layer (11) to the conductive paste layer (12); S13. Provide a third insulating layer (13) on the conductive layer (11); S14. Cure the third insulating layer (13), and the base layer (10), the conductive paste layer (12), the conductive layer (11) and the third insulating layer (13) form a conductive substrate (1); S15. Fabricate a first insulating layer (2) on the surface of the conductive substrate (1).

5. The method for fabricating the insulating bump imprint of the directional sound emission screen according to claim 4, characterized in that, In the step S15, the first insulating layer (2) is fabricated on the surface of the conductive substrate (1) by means of screen printing.

6. The method for fabricating the insulating bump imprint of the directional sound emission screen according to claim 5, characterized in that, The step S15 includes the following steps: S151. Mount the conductive substrate (1) onto the screen printing machine table, and the conductive substrate (1) is located below the screen of the screen printing machine table; S152. Print the insulating material through the screen onto the conductive substrate (1) to form the first insulating layer (2) on the surface of the conductive substrate (1); S153. Cure the first insulating layer (2).

7. The method for fabricating an insulating bump imprint of a directional sound-emitting screen according to any one of claims 1 to 3, characterized in that The following steps are further included between the step S1 and the step S2: Detect the dyne value of the first insulating layer (2). If the dyne value is lower than the first preset value, perform plasma treatment on the surface of the first insulating layer (2).

8. The method for fabricating the insulating bump imprint of the directional sound emission screen according to claim 7, characterized in that, The first preset value is 38.

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