Touch sensing structure, preparation method thereof, display panel and display device

Abstract

This invention provides a touch-sensing structure, its fabrication method, a display panel, and a display device. The touch-sensing structure includes a touch unit, which comprises a base layer, a first touch layer, a first insulating layer, a second touch layer, and a second insulating layer stacked sequentially. The first touch layer includes a plurality of first touch electrodes. The first insulating layer includes a covering area corresponding to the position of the first touch electrodes and a gap-filling area located between two adjacent first touch electrodes. The gap-filling area fills the gap between adjacent first touch electrodes and forms a partially through blind hole. The bottom end of the blind hole is spaced apart from the surface of the first touch electrode. The second touch layer includes a plurality of second touch electrodes, and parts of the second touch electrodes fill the blind hole. According to the touch-sensing structure of this application, by sharing a mask between the first touch layer and the first insulating layer, the number of mask openings is reduced.

Description

Technical Field

[0001] This invention relates to the field of touch sensing technology, specifically to a touch sensing structure and its fabrication method, a display panel, and a display device. Background Technology

[0002] As the application scenarios of smartphones and other electronic devices continue to expand, users' performance requirements for touchscreens are increasing. Capacitive touch sensors (TP sensors) are widely used in display devices due to their advantages such as low channel impedance and relatively low cost. Currently, the mainstream fabrication process for mutual capacitive metal mesh touch sensors typically employs four-mask technology, mainly including the following two technical solutions: One involves using metal materials to fabricate the complete pattern of the transmitting electrode (Tx) and receiving electrode (Rx); fabricating an insulating layer and reserving vias for electrical isolation between electrodes; fabricating a metal bridging structure to achieve electrical connection between different electrode layers; and coating the outermost protective layer to protect the sensor structure. The other involves fabricating the pattern and corresponding wiring of the transmitting electrode (Tx) or receiving electrode (Rx); fabricating an insulating layer; fabricating the pattern and wiring of the remaining electrodes (Rx or Tx); and coating a protective layer.

[0003] However, the above technical solutions have the following problems: In traditional processes, the insulating layer needs to cover the entire touch area, which makes it easy for particles to be mixed in during the curing process, resulting in poor appearance, such as bright spots or dark spots. At the same time, the four-mask process requires a large number of masks, which increases the number of masks to be opened, thus significantly increasing the manufacturing cost. Summary of the Invention

[0004] In view of this, the present invention aims to provide a touch sensing structure to solve the problems of the large number of masks and high cost required in the prior art.

[0005] In a first aspect, this application provides a touch sensing structure, including a touch unit, a plurality of first transmission lines, a plurality of first bonding pads, a plurality of second transmission lines, and a plurality of second bonding pads. The touch unit includes a base layer, a first touch layer, a first insulating layer, a second touch layer, and a second insulating layer stacked sequentially. The first touch layer includes a plurality of first touch electrodes. The first insulating layer includes a covering area corresponding to the position of the first touch electrode and a gap filling area located between two adjacent first touch electrodes. The gap filling area fills the gap between adjacent first touch electrodes and forms a partially through blind hole. The bottom end of the blind hole is spaced apart from the surface of the first touch electrode. The second touch layer includes a plurality of second touch electrodes. Parts of the second touch electrodes fill the blind hole. The first touch electrodes and the second touch electrodes together define a plurality of touch positioning areas. Parts of the first touch electrode and the second touch electrode in each touch positioning area form a mutual capacitance. The first transmission lines are used to electrically connect the first bonding pads and the plurality of first touch electrodes, and the second transmission lines are used to electrically connect the second bonding pads and the plurality of second touch electrodes.

[0006] According to the touch sensing structure of this application, the first bonding pad and the second bonding pad are located on the same layer as the second touch layer.

[0007] Optionally, the first transmission line and the first touch layer are located on the same layer, the first insulating layer is provided with a first via, the first via is filled with a first conductive layer, and the first transmission line is electrically connected to the first bonding pad through the first conductive layer.

[0008] Optionally, the first transmission line and the second touch layer are located on the same layer, the first insulating layer is provided with a second via, the second via is filled with a second conductive layer, and the first transmission line is electrically connected to the first touch electrode through the second conductive layer.

[0009] Optionally, the touch unit is disposed on the display area of ​​the display panel, and a plurality of first touch electrodes are arranged sequentially at intervals in a first direction, and a plurality of second touch electrodes are arranged sequentially at intervals in a second direction, wherein the first direction is perpendicular to the second direction and the first direction is parallel to the long side or the wide side of the display area.

[0010] According to the touch sensing structure of this application, multiple first touch electrodes can completely overlap with multiple second touch electrodes after being rotated 90° synchronously. Preferably, the touch unit is used to be disposed in the display area of ​​the display panel, and the shape of the display area is square or circular.

[0011] Secondly, this application proposes a display panel including the aforementioned touch-sensing structure.

[0012] Thirdly, this application proposes a display device including the aforementioned display panel.

[0013] Fourthly, this application proposes a preparation method for fabricating the above-mentioned touch-sensing structure, comprising:

[0014] The first touch layer is formed using a first mask;

[0015] A first insulating layer is formed using a first mask on the first touch layer;

[0016] A second touch layer is formed on the first insulating layer using a second mask;

[0017] A second insulating layer is formed on the second touch layer using a third mask.

[0018] Fifthly, this application proposes a preparation method for fabricating the above-mentioned touch-sensing structure, comprising:

[0019] The first touch layer is formed using a first mask;

[0020] A first insulating layer is formed using a first mask on the first touch layer;

[0021] A second touch layer is formed on a first insulating layer using a first mask rotated 90°.

[0022] A second insulating layer is formed on the second touch layer using a first mask rotated 90°.

[0023] A trace layer is formed on the second insulating layer using a third mask.

[0024] The technical solutions provided in this application have the following advantages compared with the prior art:

[0025] The touch sensing structure provided in this application uses the same mask to form the first insulating layer and the first touch layer. By controlling the etching time when preparing the first insulating layer, the first insulating layer can be formed on the first touch layer. By sharing a mask between the first touch layer and the first insulating layer, the number of mask openings is reduced, which not only reduces the mask manufacturing cost, but also simplifies the process steps and improves production efficiency. Attached Figure Description

[0026] Figure 1 This is a side view of a touch-sensing structure according to some embodiments of this application;

[0027] Figure 2 This is a top view of a touch-sensing structure according to some embodiments of this application;

[0028] Figure 3 This is a side view of a touch-sensing structure according to some embodiments of this application;

[0029] Figure 4 for Figure 3A side view of the film layer from another direction of the touch-sensing structure of the same embodiment;

[0030] Figure 5 This is a top view of a touch-sensing structure according to some embodiments of this application;

[0031] Figure 6 This is a top view of a portion of the film layer of a touch-sensing structure according to some embodiments of this application;

[0032] Figure 7 This is a flowchart illustrating the preparation method according to some embodiments of this application;

[0033] Figure 8 This is a flowchart illustrating the preparation method according to some embodiments of this application.

[0034] Figure description: First touch layer 10, first touch electrode 11, first insulating layer 20, blind hole 21, second touch layer 30, second touch electrode 31, second insulating layer 40, base layer 50. Detailed Implementation

[0035] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] like Figure 1 and Figure 2As shown, the touch sensing structure according to an embodiment of this application includes a touch unit, a plurality of first transmission lines, a plurality of first bonding pads, a plurality of second transmission lines, and a plurality of second bonding pads. The touch unit includes a base layer 50, a first touch layer 10, a first insulating layer 20, a second touch layer 30, and a second insulating layer 40 stacked sequentially. The first touch layer 10 includes a plurality of first touch electrodes 11. The first insulating layer 20 includes a covering area corresponding to the position of the first touch electrode 11 and a gap filling area located between two adjacent first touch electrodes 11. The gap filling area fills the gap between two adjacent first touch electrodes 11. The gaps between them form a partially through blind hole 21. The bottom end of the blind hole 21 is spaced apart from the surface of the first touch electrode 11. The second touch layer 30 includes a plurality of second touch electrodes 31. Parts of the second touch electrodes 31 fill the blind hole 21. The first touch electrode 11 and the second touch electrode 31 together define a plurality of touch positioning areas. Parts of the first touch electrode 31 and the second touch electrode 32 in each touch positioning area form a mutual capacitance. The first transmission line is used to electrically connect the first bonding pad and the plurality of first touch electrodes 11. The second transmission line is used to electrically connect the second bonding pad and the plurality of second touch electrodes 31.

[0037] in, Figure 1 A side view of a touch-sensing structure according to an embodiment is shown, showing a film layer stack structure, from bottom to top consisting of a base layer 50, a first touch layer 10, a first insulating layer 20, a second touch layer 30, and a second insulating layer 40.

[0038] In some embodiments, the first touch electrode 11 is used to transmit touch signals (such as the Tx electrode), and the second touch electrode 31 is used to receive touch signals (such as the Rx electrode). In some embodiments, the first touch electrode 11 is used to receive touch signals (such as the Rx electrode), and the second touch electrode 31 is used to transmit touch signals (such as the Tx electrode).

[0039] The touch unit of the touch sensing structure is used to correspond to the display area of ​​the display panel. The display area includes a substrate and a touch unit disposed on the substrate. The first touch layer 10 is stacked and in contact with the substrate, and the second insulating layer 40 is away from the substrate. The traces of the touch sensing structure are used to correspond to the non-display area of ​​the display panel.

[0040] The material used to make the first touch electrode 11 can be a low-resistivity metal such as copper (Cu), silver (Ag), aluminum (Al) and indium tin oxide (ITO), and the thickness is usually 50-200nm.

[0041] The first insulating layer 20 includes a covering area corresponding to the position of the first touch electrode 11. The orthographic projection of the covering area on the first touch layer 10 completely coincides with the first touch electrode 11. It also includes a gap-filling area located between two adjacent first touch electrodes 11. The gap-filling area fills the gap between the two adjacent first touch electrodes 11 and forms a partially penetrated blind hole 21. The gap-filling area and the covering area are formed in one step. The first insulating layer 20 can be formed using a mask formed with the first touch layer 10. By controlling the etching time, the gap-filling area and the blind hole 21 are formed, ensuring that the first insulating layer 20 can isolate the first touch electrode 11 and the second touch electrode 31. The material used to form the first insulating layer 20 can be a curable resin (e.g., polyimide, photoresist), and its thickness can be 1-3 μm.

[0042] In some embodiments, the first touch electrode 11 is a mesh structure, such as a rhomboid or square mesh, with its mesh lines extending along the long side of the display area. In this case, the coverage area of ​​the first insulating layer 20 needs to completely cover the surface of all the mesh lines of the first touch electrode 11, and the gap filling area is opposite to the gap between the mesh lines.

[0043] In some embodiments, the second touch electrode 31 is a mesh structure, such as a rhomboid or square mesh, with its mesh lines extending along the long side of the display area. In this case, the coverage area of ​​the second insulating layer 40 needs to completely cover the surface of all the mesh lines of the second touch electrode 31, and the gap filling area is opposite to the gap between the mesh lines.

[0044] The first touch electrode 11 can be a simple shape, such as a straight line or a broken line. For example, the first touch electrode 11 is configured as a straight metal line extending along the long side of the display area. Figure 2 As shown, the first touch electrode 11 is completely covered by the first insulating layer 20.

[0045] The shape of the second touch electrode 31 can be the same as or different from the shape of the first touch electrode 11. For example, in a specific embodiment, the first touch electrode 11 is a straight metal line extending along the long side of the display area, and the second touch electrode 31 is a straight metal line extending along the short side of the display area. The first touch electrode 11 and the second touch electrode 31 have the same shape and intersect. Figure 2 As shown.

[0046] For example, in one specific embodiment, the first touch electrode 11 is formed as a straight metal line extending along the long side of the display area, and the plurality of second touch electrodes 31 are formed as a metal mesh, such as... Figure 6As shown. For example, in one specific embodiment, a plurality of first touch electrodes 11 are formed in a metal mesh shape, and a plurality of second touch electrodes 31 are formed in a metal mesh shape, as shown. Figure 5 As shown, the first touch electrode 11 is completely covered by the first insulating layer 20.

[0047] The second insulating layer 40 may cover the entire second touch layer 30 and part of the non-display area, or it may only cover part of the second touch electrode 31 in the touch positioning area. This can be configured as needed to ensure protection and optimize capacitance performance. The material used to make the second insulating layer 40 may be the same as or different from the material used to make the first insulating layer 20. If the material used to make the second insulating layer 40 is different from the material used to make the first insulating layer 20, the material used to make the second insulating layer 40 may be silicon dioxide or silicon nitride, and the thickness may be 1-2 μm.

[0048] The first bonding pad can both send control signals to the first touch electrode 11 and receive sensing signals from the first touch electrode 11 via the first transmission line. The first bonding pad is used for electrical connection with the driver chip. The first transmission line adopts a "one-to-many" connection method (one first transmission line connects multiple first touch electrodes 11), which can significantly reduce the number of first bonding pads and the complexity of the first transmission line wiring. The first transmission line can correspond to 2 to 10 first touch electrodes 11. For example, in some embodiments, the first transmission line corresponds to two first touch electrodes 11; in some embodiments, the first transmission line corresponds to three first touch electrodes 11; in some embodiments, the first transmission line corresponds to four first touch electrodes 11; in some embodiments, the first transmission line corresponds to five first touch electrodes 11; in some embodiments, the first transmission line corresponds to six first touch electrodes 11; in some embodiments, the first transmission line corresponds to seven first touch electrodes 11; in some embodiments, the first transmission line corresponds to eight first touch electrodes 11; in some embodiments, the first transmission line corresponds to nine first touch electrodes 11; and in some embodiments, the first transmission line corresponds to ten first touch electrodes 11.

[0049] The second bonding pad can both send control signals to the second touch electrode 31 and receive sensing signals from the second touch electrode 31 via the second transmission line. The second bonding pad is used for electrical connection with the driver chip. The second transmission line adopts a "one-to-many" connection method (one second transmission line connects multiple second touch electrodes 31), which can significantly reduce the number of second bonding pads and the complexity of the second transmission line wiring. The second transmission line can correspond to 2 to 10 second touch electrodes 31. For example, in some embodiments, the second transmission line corresponds to two second touch electrodes 31; in some embodiments, the second transmission line corresponds to three second touch electrodes 31; in some embodiments, the second transmission line corresponds to four second touch electrodes 31; in some embodiments, the second transmission line corresponds to five second touch electrodes 31; in some embodiments, the second transmission line corresponds to six second touch electrodes 31; in some embodiments, the second transmission line corresponds to seven second touch electrodes 31; in some embodiments, the second transmission line corresponds to eight second touch electrodes 31; in some embodiments, the second transmission line corresponds to nine second touch electrodes 31; and in some embodiments, the second transmission line corresponds to ten second touch electrodes 31.

[0050] For example, when the first touch electrode is a Tx electrode and the second touch electrode is an Rx electrode, when an external signal is input, such as an AC voltage, to excite the electric field of the mutual capacitance, the function of the first transmission line is to transmit the electrical signal of the first bonding pad to the first touch electrode 11 electrically connected to the first transmission line, ensuring that the first touch electrode 11 electrically connected to the first transmission line can synchronously receive the drive signal. The first bonding pad is electrically connected to the driver chip. The function of the second transmission line is to transmit the charge changes sensed by the multiple second touch electrodes 31 electrically connected to the second transmission line to the second bonding pad. The second bonding pad is electrically connected to the driver chip, and the driver chip collects these signals through the second bonding pad to calculate the touch position.

[0051] The function of the first transmission line is to accurately and efficiently transmit the touch signal sensed by the first touch electrode 11 to the first bonding pad, and then connect to the external driving circuit through the first bonding pad to realize the detection and recognition of touch operation. For example, when a finger touches a display panel with a touch-sensing structure, the first touch electrode 11 will generate an electrical signal due to the change in mutual capacitance, and the first transmission line is responsible for transmitting this signal. The first transmission line can correspond one-to-one with the first bonding pad, or multiple first transmission lines can correspond to one first bonding pad; or some first transmission lines can correspond to one first bonding pad, and other first transmission lines can correspond one-to-one with the first bonding pad. The correspondence between the first touch electrode 11 and the first transmission line can be one-to-one between each first touch electrode 11 and each first transmission line; or multiple first touch electrodes 11 can correspond to the same first transmission line.

[0052] The function of the second transmission line is to accurately and efficiently transmit the touch signal sensed by the second touch electrode 31 to the second bonding pad, and then connect to the external driving circuit through the second bonding pad to realize the detection and recognition of touch operation. For example, when a finger touches the display panel with the touch sensing structure, the second touch electrode 31 will generate an electrical signal due to the change in mutual capacitance, and the second transmission line is responsible for transmitting this signal. The second transmission line can correspond one-to-one with the second bonding pad, or multiple second transmission lines can correspond to one second bonding pad; or some second transmission lines can correspond to one second bonding pad, and other second transmission lines can correspond one-to-one with the second bonding pad. The correspondence between the second touch electrode 31 and the second transmission line can be one-to-one between each second touch electrode 31 and each second transmission line, or multiple second touch electrodes 31 can correspond to the same second transmission line.

[0053] According to the touch sensing structure of this application embodiment, the first insulating layer 20 includes a covering area and a gap filling area. The orthographic projection of the covering area on the first touch layer 10 completely coincides with the first touch electrode 11, and the gap filling area is located between two adjacent first touch electrodes 11. The gap filling area fills the gap between two adjacent first touch electrodes 11 and forms a partially penetrated blind hole 21. The gap filling area and the covering area are formed in one step. The first touch layer 10 and the first insulating layer 20 can be prepared using the same mask. When forming the first insulating layer 10, the gap filling area and the covering area are formed by controlling the etching time. In this way, by sharing a mask for the first touch layer 10 and the first insulating layer 20, the number of mask openings is reduced, which not only reduces the mask manufacturing cost but also simplifies the process steps and improves production efficiency. The second insulating layer 40 can effectively prevent the external environment from eroding the second touch layer 30 and reduce interlayer signal interference. Furthermore, compared to the fully coated insulation layer in traditional processes, the insulation layer coating area of ​​this application is significantly reduced, which greatly reduces the probability of particle contamination during the curing process of the first insulation layer 20, thereby reducing appearance defects (such as bright spots and dark spots) caused by particle contamination and improving product yield and reliability.

[0054] According to the touch sensing structure of the present application embodiment, the first bonding pad and the second bonding pad are located on the same layer as the second touch layer 30.

[0055] In the above embodiments, the first bonding pad and the second bonding pad are all located on the same layer as the second touch layer 30. Compared to setting the first bonding pad on the same layer as the first touch layer 10, this avoids the first bonding pad being covered by the first insulating layer 20 (since the first insulating layer 20 is formed by using the same mask as the first touch layer 10). This allows the first bonding pad to be directly exposed for soldering, eliminating the via process and simplifying the manufacturing process. At the same time, the second bonding pad is on the same layer as the second touch layer 30, resulting in a shorter signal transmission path and eliminating the need to pass through the high impedance point of the via, thus reducing signal attenuation. In addition, since the first bonding pad and the second bonding pad are all located on the same layer as the second touch layer 30, they can be manufactured simultaneously using the same mask as the second touch layer 30, eliminating the need for additional masks and reducing mask mold opening costs.

[0056] In some embodiments, the wiring layout may be such that the left half consists of the first transmission line and the right half consists of the second transmission line.

[0057] In some embodiments, the first transmission line and the first touch layer 10 are located on the same layer, the first insulating layer 20 is provided with a first via, the first via is filled with a first conductive layer, and the first transmission line is electrically connected to the first bonding pad through the first conductive layer.

[0058] In the above embodiments, the first transmission line and the first touch layer 10 are disposed on the same layer, allowing the first transmission line to be formed simultaneously with the formation of the first touch electrode 11. If the layout of the first transmission line is complex, the first via can be positioned close to the first bonding pad in the extension direction of the first transmission line. This ensures effective signal transmission while allowing for a reasonable arrangement of the first via's position within a limited space. For example, the first via can also be positioned at the edge region of the first insulating layer 20, so that the first transmission line can achieve electrical connection with the first bonding pad through the first conductive layer.

[0059] The first transmission line and the first contact layer are located on the same layer, and the second transmission line and the second touch layer 30 are located on the same layer. The first transmission line and the second transmission line can be arranged alternately, or they can be arranged as needed. This application does not impose any restrictions.

[0060] In some embodiments, the first transmission line and the second touch layer 30 are located on the same layer. The first insulating layer 20 is provided with a second via, which is filled with a second conductive layer. The first transmission line is electrically connected to the first touch electrode 11 through the second conductive layer. Because the first transmission line and the second touch layer 30 are located on the same layer, the first transmission line can be electrically connected to the first bonding pad without the need for a via. In some embodiments, the second via is located in the area where the orthographic projections of the first transmission line and the first touch electrode 11 overlap, which shortens the signal transmission path. The second via can also be located in the edge area of ​​the first touch electrode 11 or in the empty area of ​​two adjacent first touch electrodes 11.

[0061] In some embodiments, the touch unit is disposed on the display area of ​​the display panel. A plurality of first touch electrodes 11 are arranged sequentially at intervals along a first direction, and a plurality of second touch electrodes 31 are arranged sequentially at intervals along a second direction, wherein the first direction is perpendicular to the second direction and parallel to the long or wide side of the display area. Because the plurality of first touch electrodes 11 are arranged sequentially at intervals along the first direction, and the plurality of second touch electrodes 31 are arranged sequentially at intervals along the second direction perpendicular to the first direction, the first touch electrodes 11 and second touch electrodes 31 intersect each other. Each intersection point forms a mutual capacitance. When a finger touches the screen, the value of the mutual capacitance at that location changes. The first touch electrodes 11 and second touch electrodes 31 are arranged perpendicularly to each other, making the touch sensing area of ​​the entire display area more uniform and densely distributed. When a finger touches the screen, the values ​​of multiple mutual capacitances can be changed more effectively, thereby improving the sensitivity of touch sensing. Of course, this arrangement can also reduce signal interference between adjacent electrodes. Because the first and second directions are perpendicular to each other, the electrode signals in different directions are relatively independent, reducing the possibility of signal crosstalk, which allows the touch signal to be detected and processed more accurately, further improving touch sensitivity.

[0062] The first direction can be parallel to either the long or wide side of the display area, allowing the touch unit structure to adapt to display areas of different shapes and sizes. Whether it's a long, narrow display area (such as a smartwatch screen) or a regular rectangular display area (such as a mobile phone or tablet screen), the parallelism between the first direction and the edge of the display area can be adjusted according to the actual situation to achieve a good combination of touch and display functions.

[0063] In addition, the first touch electrode 11 and the second touch electrode 31 are arranged in a regular row and column manner, which makes the layout of the transmission lines (including the first transmission line and the second transmission line, the first transmission line is connected to the first touch electrode 11 and the second transmission line is connected to the second touch electrode 31) and the bonding pads (including the first bonding pad and the second bonding pad, the first bonding pad is connected to the first transmission line and the second bonding pad is connected to the second transmission line) more regular, which helps to simplify circuit design, reduce wiring complexity and reduce manufacturing costs.

[0064] like Figure 3 and Figure 4 As shown, in the touch sensing structure according to an embodiment of this application, the plurality of first touch electrodes 11 can completely overlap with the plurality of second touch electrodes 31 after being rotated 90° synchronously. This symmetry allows the same mask to be used when forming the first touch layer 10 and when forming the second touch layer 30.

[0065] During the manufacturing process, the same mask can be directly used for exposure when forming the second touch electrode 31 by rotating it by 90°. For example: the first mask is used to make the first touch layer 10; then the first mask is used to form the first insulating layer 20 on the first touch layer 10; the first mask is rotated by 90° to make the second touch layer 30.

[0066] In the above embodiments, this configuration allows the touch sensing structure to be completed using only two masks. Specifically, the first touch layer 10, the first insulating layer 20, the second touch layer 30, and the second insulating layer 40 share a common mask, while the wiring layer is fabricated using a different mask. Compared to the traditional process that requires four masks, this reduces the number of masks used, thereby lowering production costs.

[0067] In some embodiments, the touch unit is disposed on the display area of ​​the display panel, and the shape of the display area is square or circular.

[0068] In other words, in some embodiments, the display area is square in shape, with the long side and the wide side being equal in length. The first touch electrode 11 (along the long side) and the second touch electrode 31 (along the wide side) form a regular grid structure, with each intersection corresponding to a touch positioning area. The spacing between any two adjacent first touch electrodes 11 is consistent, and the spacing between any two adjacent second touch electrodes 31 is also consistent, which can improve space utilization and avoid a decrease in touch sensitivity in the edge area due to the reduced density of the first touch electrodes 11 and the second touch electrodes 31.

[0069] In some embodiments, when the display area is circular, the shapes of the first touch electrode 11 and the second touch electrode 31 can both be straight, spiral, or wavy.

[0070] The display panel according to the embodiments of this application includes the touch sensing structure described above.

[0071] According to the display panel of this application embodiment, the coating area of ​​the first insulating layer 20 significantly reduces the probability of particles (such as dust and impurities) being mixed in during the curing process, reducing appearance defects such as bright spots and dark spots on the display panel caused by particle contamination. Local coating avoids the problem of uneven thickness in edge areas when fully coated, improving interlayer uniformity, reducing the risk of abnormal touch signals, reducing the manufacturing difficulty of the first touch layer 10 and the second touch layer 30, and simultaneously reducing defects caused by process errors, thus improving the overall yield of the display panel. For example, in foldable screen applications, reducing the coating area of ​​the first insulating layer 20 can reduce material accumulation in unnecessary areas, reduce stress concentration when the display panel is bent, thereby extending its service life. The display panel includes a substrate, and the touch sensing structure is stacked on the substrate.

[0072] In this application's embodiment of the display panel, the material of the pad substrate can be soda-lime glass, quartz glass, sapphire glass, or other glass materials, or it can be stainless steel, aluminum, nickel, or other metal materials. In another embodiment of this application, the material of the substrate can be polymethyl methacrylate (PVP), polyvinyl alcohol (PVA), polyvinyl phenol (PVP), polyether sulfone (PES), polyimide, polyamide, polyacetal, polycarbonate (PC), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), or a combination thereof. In yet another embodiment of this application, the substrate is a flexible substrate, and the material can be polyimide (PI). The substrate can also be a composite of multiple materials. For example, in a specific embodiment, the substrate may include a base film layer, a pressure-sensitive adhesive layer, a first polyimide layer and a second polyimide layer stacked sequentially.

[0073] The display device according to the embodiments of this application includes the display panel described above.

[0074] The display device according to the embodiments of this application can reduce production costs while ensuring the reliability of touch accuracy, thereby providing users with a good user experience.

[0075] The display device of this application may include a touch sensing structure, an optical film (such as a microlens or a polarizer), a cover plate, and other structures disposed on the light-emitting side of the display panel.

[0076] For example, the display device can be any product or component with display functionality, such as a television, digital camera, mobile phone, watch, tablet computer, laptop computer, or navigator.

[0077] like Figure 7 As shown, the preparation method according to this application, for fabricating the above-mentioned touch sensing structure, includes:

[0078] Step S102: Form the first touch layer 10 using the first mask;

[0079] Step S104: Form a first insulating layer 20 using a first mask on the first touch layer 10;

[0080] Step S106: Form a second touch layer 30 on the first insulating layer 20 using a second mask;

[0081] Step S108: A second insulating layer 40 is formed on the second touch layer 30 using a third mask.

[0082] In step S102, the following method can be used to form the first touch layer 10: a layer of photoresist is uniformly coated on a suitable substrate layer 50 material; a first mask is placed over the photoresist-coated substrate layer 50; and exposure is performed using a specific light source such as ultraviolet light. The first mask has pre-designed transparent and opaque areas; the exposed or unexposed portions of the photoresist (depending on the type of photoresist) are removed using a developing solution, thereby forming a pattern corresponding to the multiple first touch electrodes 11 on the photoresist layer; a layer of metal is deposited on the surface of the substrate layer 50 using a physical vapor deposition (PVD) method, such as sputtering or evaporation; commonly used metals include copper, silver, and indium tin oxide (ITO); the metal outside the photoresist-covered area is removed using an etching solution, leaving the portion identical to the photoresist pattern, forming the first touch layer 10. Finally, the remaining photoresist is removed using a photoresist remover. Alternatively, the first touch layer 10 can be formed using methods such as screen printing or inkjet printing.

[0083] In step S104, photoresist is first coated on the surface of the first touch layer 10, and then exposed and developed using a first mask to form a pattern corresponding to the first insulating layer 20. An insulating material, such as an organic insulating polymer (polyimide, acrylic resin, etc.) or an inorganic oxide (such as SiO2), is uniformly coated on the surface of the first touch layer 10 by spin coating, spraying, or other methods. The insulating material outside the photoresist-covered area is removed using etching or stripping processes to finally form the first insulating layer 20. Finally, the remaining photoresist is removed.

[0084] In step S106, similar to step S102, photoresist is first coated onto the first insulating layer 20, then exposed and developed using a second mask, followed by metal deposition (such as PVD) and etching to remove excess metal, forming the second touch layer 30. Finally, the photoresist is removed. Alternatively, screen printing or inkjet printing can be used to print metal paste or ink onto the first insulating layer 20 according to the pattern of the second mask, and after curing, the second touch layer 30 is formed.

[0085] In step S108, photoresist is first coated onto the surface of the second touch layer 30, and then exposed and developed using a third mask to form a specific pattern on the photoresist. Next, an insulating material (such as SiO2 or an organic insulating polymer) is coated, and excess insulating material is removed by etching or stripping to form the second insulating layer 40. Finally, the photoresist is removed. Alternatively, screen printing or inkjet printing can be used to print the insulating paste or ink onto the second touch layer 30 according to the pattern of the third mask, followed by curing to form the second insulating layer 40. This method allows for precise control of the shape and thickness of the second insulating layer 40 according to design requirements.

[0086] like Figure 8 As shown, this application proposes a preparation method for fabricating the above-mentioned touch sensing structure, comprising:

[0087] Step S201: Form the first touch layer 10 using the first mask;

[0088] Step S202: A first insulating layer 20 is formed on the first touch layer 10 using a first mask;

[0089] Step S203: A second touch layer 30 is formed on the first insulating layer 20 using a first mask rotated 90°.

[0090] Step S204: A second insulating layer 40 is formed on the second touch layer 30 using a first mask rotated by 90°;

[0091] Step S205: A wiring layer is formed on the second insulating layer 40 using a third mask.

[0092] In step S201, the first touch layer 10 is formed using a first mask through processes such as cleaning the substrate layer 50, applying photoresist, exposure, development, metal deposition, and etching. Alternatively, the first touch layer 10 can be formed using methods such as screen printing or inkjet printing.

[0093] In step S202, the photolithography process can be used again. For example, photoresist can be coated again on the surface of the first touch layer 10, and the first mask can be used for exposure and development to form the first insulating layer 20.

[0094] In step S203, a second touch layer 30 is formed on the first insulating layer 20, which together with the first touch layer 10 forms multiple touch positioning areas to achieve more precise touch sensing. A photolithography process can be used again: first, photoresist is coated on the first insulating layer 20; then, a first mask rotated 90° is used for exposure and development; next, metal deposition and etching are performed to remove excess metal, forming the second touch layer 30; finally, the photoresist is removed.

[0095] In step S204, photoresist is coated on the surface of the second touch layer 30, and exposure and development are performed using a first mask rotated 90°; an insulating material is coated, such as SiO2 or organic insulating material coated by CVD or spin coating; excess insulating material is removed, and a second insulating layer 40 is formed by etching or stripping process; finally, the remaining photoresist is removed.

[0096] In step S205, a wiring layer is formed on the second insulating layer 40, thereby connecting the first touch layer 10 and the second touch layer 30 to an external circuit, thus realizing the transmission of touch signals. Photoresist is coated on the surface of the second insulating layer 40, and exposure and development are performed using a third mask to form a wiring pattern.

[0097] When forming the wiring layer, metal deposition is performed first, such as depositing copper, aluminum, or other metals through sputtering or evaporation. Then, excess metal is etched away, leaving the metal beneath the photoresist to form the wiring layer. Finally, the remaining photoresist is removed.

[0098] According to the preparation method of the present application embodiment, a first touch layer 10 and a first insulating layer 20 can be formed by a first mask, and a second touch layer 30 and a second insulating layer 40 can be formed by rotating the first mask, thereby reducing the manufacturing cost of the mask.

[0099] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A touch sensing structure, characterized in that, The device includes a touch unit, multiple first transmission lines, multiple first bonding pads, multiple second transmission lines, and multiple second bonding pads. The touch unit comprises a base layer, a first touch layer, a first insulating layer, a second touch layer, and a second insulating layer stacked sequentially. The first touch layer includes multiple first touch electrodes. The first insulating layer includes a coverage area corresponding to the position of the first touch electrode and a gap-filling area located between two adjacent first touch electrodes. The gap-filling area fills the gap between two adjacent first touch electrodes and forms a partially through-hole. The bottom end of the blind hole is spaced apart from the surface of the first touch electrode. The second touch layer includes multiple second touch electrodes, and portions of the second touch electrodes fill the blind holes. The first touch electrodes and the second touch electrodes together define multiple touch positioning areas. A portion of the first touch electrode and a portion of the second touch electrode in each touch positioning area form a mutual capacitance. The first transmission lines are used to electrically connect the first bonding pads and the multiple first touch electrodes, and the second transmission lines are used to electrically connect the second bonding pads and the multiple second touch electrodes.

2. The touch sensing structure according to claim 1, characterized in that, The first bonding pad and the second bonding pad are located on the same layer as the second touch layer.

3. The touch sensing structure according to claim 2, characterized in that, The first transmission line and the first touch layer are located on the same layer. The first insulating layer is provided with a first via, and the first via is filled with a first conductive layer. The first transmission line is electrically connected to the first bonding pad through the first conductive layer.

4. The touch sensing structure according to claim 2, characterized in that, The first transmission line and the second touch layer are located on the same layer. The first insulating layer is provided with a second via, and the second via is filled with a second conductive layer. The first transmission line is electrically connected to the first touch electrode through the second conductive layer.

5. The touch sensing structure according to claim 2, characterized in that, The touch unit is disposed on the display area of ​​the display panel. A plurality of first touch electrodes are arranged at intervals in a first direction, and a plurality of second touch electrodes are arranged at intervals in a second direction. The first direction is perpendicular to the second direction and is parallel to the long side or the wide side of the display area.

6. The touch sensing structure according to claim 1, characterized in that, After the multiple first touch electrodes are rotated 90° synchronously, they can completely overlap with the multiple second touch electrodes. Preferably, the touch unit is used to be disposed in the display area of ​​the display panel, and the shape of the display area is square or circular.

7. A display panel, characterized in that, Includes the touch sensing structure as described in any one of claims 1-6.

8. A display device, characterized in that, Includes the display panel as described in claim 7.

9. A method for fabricating a touch-sensing structure as described in any one of claims 1-5, characterized in that, include: The first touch layer is formed using a first mask; A first insulating layer is formed on the first touch layer using the first mask; A second touch layer is formed on the first insulating layer using a second mask; A second insulating layer is formed on the second touch layer using a third mask.

10. A method for fabricating the touch-sensing structure as described in claim 6, characterized in that, include: The first touch layer is formed using a first mask; A first insulating layer is formed on the first touch layer using the first mask; A second touch layer is formed on the first insulating layer using the first mask rotated 90°; A second insulating layer is formed on the second touch layer using the first mask rotated 90°; A trace layer is formed on the second insulating layer using a third mask.

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