Capacitive screen ITO line short circuit prevention structure

Abstract

The application discloses a kind of short-circuit prevention structure of capacitive screen ITO line, comprising: substrate, ITO electrode layer, insulating layer and signal transmission layer, ITO electrode layer is set to substrate top, at least one ITO main channel is equipped on ITO electrode layer, ITO main channel side is provided with isolation line, insulating layer is set to ITO electrode layer top, signal transmission layer is set to insulating layer top.The application is provided with isolation line on the side of ITO main channel, effectively blocks abnormal conduction path, prevents the short-circuit phenomenon caused by static electricity or foreign matter, significantly improves the electrical safety and product reliability of capacitive screen.

Description

Technical Field

[0001] This invention relates to the technical field of touch screens, and more particularly to a short-circuit protection structure for ITO circuitry in a capacitive touch screen. Background Technology

[0002] Currently, capacitive touchscreens are widely used in electronic devices such as mobile phones and tablets due to their high touch sensitivity and high light transmittance. In the manufacturing process of capacitive touchscreens, an ITO electrode layer is typically fabricated on a substrate to achieve touch sensing functionality. However, in existing ITO circuit structures, there is often a lack of effective isolation between the ITO main channel and surrounding metal traces or other conductive structures. During actual use or production, electrostatic breakdown, the falling of conductive foreign objects, or film layer breakage and overlap can easily lead to unexpected electrical connections between the ITO main channel and surrounding circuits, causing short circuits. This short circuit problem not only severely affects the touch accuracy and response speed of the touchscreen but may even cause the touchscreen to malfunction, reducing product yield and reliability. Summary of the Invention

[0003] The present invention aims to at least partially solve one of the technical problems in the related art.

[0004] Therefore, the purpose of this invention is to propose a short-circuit protection structure for ITO lines in a capacitive touchscreen. An isolation line is set on one side of the ITO main channel to effectively block abnormal conductive paths, thereby improving the short-circuit protection capability of the line and the reliability of the product.

[0005] To achieve the above objectives, the present invention proposes a short-circuit protection structure for ITO circuits in a capacitive touchscreen, comprising a substrate, an ITO electrode layer, an insulating layer, and a signal transmission layer. The ITO electrode layer is disposed on the top of the substrate, and at least one ITO main channel is provided on the ITO electrode layer. An isolation line is provided on one side of the ITO main channel. The insulating layer is disposed on the top of the ITO electrode layer, and the signal transmission layer is disposed on the top of the insulating layer.

[0006] In addition, the short-circuit protection structure for ITO lines of the capacitive touchscreen proposed according to the present invention may also have the following additional technical features:

[0007] Specifically, the isolation line includes a first laser isolation line and a second laser isolation line, which are respectively disposed on both sides of the ITO main channel and have a preset distance between them.

[0008] Specifically, the width of both the first laser isolation line and the second laser isolation line is 0.1 mm to 0.4 mm.

[0009] Specifically, the signal transmission layer is a metal trace layer, which includes metal traces arranged around the periphery of the ITO electrode layer, and the isolation line is electrically connected to the metal traces.

[0010] Specifically, the ITO electrode layer is an X-channel electrode array, and the signal transmission layer is a Y-channel electrode array.

[0011] The Y-channel electrode array includes multiple electrode units and an ITO bridging layer connecting adjacent electrode units. The ITO bridging layer is disposed above the insulating layer, and the isolation line is disposed in the gap between adjacent ITO main channels.

[0012] The insulating layer is an OC insulating layer, which completely covers the ITO electrode layer.

[0013] It also includes a filling insulation layer disposed between the isolation line and the ITO main channel, the filling insulation layer being used to fill the step gap between the isolation line and the ITO main channel.

[0014] A capacitive touchscreen includes a short-circuit protection structure for the capacitive touchscreen ITO circuitry.

[0015] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects:

[0016] By installing isolation lines on one side of the ITO main channel, a physical short-circuit barrier is constructed. When static electricity or conductive foreign objects attempt to form a short-circuit path between the ITO main channel and surrounding lines, the isolation lines can effectively block the path or guide the static charge to a safe area, thereby preventing direct damage to the ITO main channel. In particular, the laser-insulated line solution allows for precise control of the line's position and width, ensuring isolation effectiveness while minimizing the impact on the effective touch area of ​​the screen. Furthermore, the insulating layer fills the step gaps between lines, eliminating gaps where conductive foreign objects can easily accumulate or where tip discharge can occur, further enhancing the structure's stability and short-circuit protection.

[0017] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0018] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0019] Figure 1 This is a schematic diagram of the short-circuit protection structure of the ITO circuit of the capacitive touchscreen of the present invention;

[0020] Figure 2 for Figure 1 Enlarged view of a portion of point A in the middle.

[0021] As shown in the figure: 1. Substrate; 2. ITO electrode layer; 3. ITO main channel; 4. Insulating layer; 5. Signal transmission layer; 6. Isolation line; 7. First laser isolation line; 8. Second laser isolation line; 9. Filling insulating layer. Detailed Implementation

[0022] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the invention, and should not be construed as limiting the invention. Rather, embodiments of the invention include all variations, modifications, and equivalents falling within the spirit and scope of the appended claims.

[0023] Example 1:

[0024] like Figure 1-2 As shown, this embodiment provides a short-circuit protection structure for ITO circuitry in a capacitive touchscreen. The structure includes a substrate 1, an ITO electrode layer 2, an insulating layer 4, and a signal transmission layer 5.

[0025] Specifically, this embodiment constructs a bottom-up layered structure system. The substrate 1, serving as the supporting carrier of the entire structure, is typically made of a material with high light transmittance and certain mechanical strength, such as a glass substrate 1 or a flexible polyethylene terephthalate (PET) substrate 1. An ITO electrode layer 2 is disposed on top of the substrate 1, and it is formed with specific conductive patterns through processes such as magnetron sputtering or photolithography. An insulating layer 4 is disposed on top of the ITO electrode layer 2, serving to provide electrical isolation and protection for the underlying electrodes. A signal transmission layer 5 is disposed on top of the insulating layer 4, used to transmit touch detection signals or connect to external circuits.

[0026] In this embodiment, at least one ITO main channel 3 is provided on the ITO electrode layer 2. This ITO main channel 3 is the core functional area for touch sensing of the capacitive screen, responsible for generating an induced electric field and detecting the touch position. An isolation line 6 is provided on one side of the ITO main channel 3. The term "one side" as used herein includes both single-sided and double-sided or multi-sided arrangements of the ITO main channel 3. The isolation line 6 is physically spaced apart from the ITO main channel 3, and this distance constitutes a physical barrier to block abnormal conductive paths.

[0027] From a microscopic perspective, in existing technologies, when electrostatic charge accumulates or conductive foreign objects fall, an unexpected low-impedance path can easily form between the ITO main channel 3 and the surrounding conductive structure, leading to a short circuit. This embodiment, by introducing an isolation line 6 on one side of the ITO main channel 3, effectively sets up a "firewall" on the potential short-circuit path. When abnormal current attempts to propagate outward from the ITO main channel 3, the presence of the isolation line 6 cuts off the direct current conduction path or significantly extends the creepage distance, thereby effectively preventing short circuits. It should be understood that although... Figure 1 The diagram shows a stacked structure, but in actual manufacturing, the isolation line 6 can be a non-conductive trench formed by etching on the same layer as the ITO main channel 3, or it can be an insulating barrier formed by subsequent processing, as long as it can achieve the function of physical isolation.

[0028] Through the above solution, this embodiment utilizes the physical isolation effect of the isolation line 6 to significantly improve the short-circuit protection capability and product reliability of the capacitive touchscreen ITO circuit without significantly increasing process complexity and cost.

[0029] Example 2:

[0030] This embodiment further refines the specific structure and parameters of the isolation line 6 based on embodiment 1. Specifically, the isolation line 6 includes a first laser isolation line 7 and a second laser isolation line 8, which are respectively disposed on both sides of the ITO main channel 3 and have a preset distance between them.

[0031] In this embodiment, the first laser isolation line 7 and the second laser isolation line 8 are non-conductive trenches formed on the surface of the ITO electrode layer 2 using a laser etching process. This dual-line symmetrical layout design can build a double physical barrier on both sides of the ITO main channel 3, providing a more balanced and reliable short-circuit protection effect compared to single-sided isolation. The preset spacing is to ensure that there is a sufficient electrical safety distance between the isolation line 6 and the main channel, preventing arcing caused by insufficient spacing, while also avoiding wasted wiring resources due to excessive spacing.

[0032] Furthermore, the width of both the first laser isolation line 7 and the second laser isolation line 8 is 0.1 mm to 0.4 mm.

[0033] This parameter range is an optimal range derived from extensive experimental verification. Specifically, if the width of the isolation line is less than 0.1mm, for example, 0.05mm, although it saves wiring space, the narrow width makes it prone to breakage or residual conductive particles in subsequent manufacturing processes, preventing the isolation line 6 from completely cutting off the conductive path and significantly reducing the short-circuit protection effect. Conversely, if the width of the isolation line is greater than 0.4mm, for example, 0.5mm, although the isolation effect is guaranteed, the excessively wide isolation line will occupy too much of the surface area of ​​the ITO electrode layer 2, reducing the effective sensing area of ​​the ITO main channel 3, thereby reducing the aperture ratio and light transmittance of the touch screen and affecting touch sensitivity.

[0034] Therefore, limiting the width of the isolation line to between 0.1mm and 0.4mm, such as 0.1mm, 0.25mm or 0.4mm, can ensure the formation of an effective physical isolation barrier to block abnormal conductive paths, while maximizing the preservation of the effective area of ​​the ITO main channel 3, thus achieving the best balance between short-circuit protection and touch performance.

[0035] Example 3:

[0036] This embodiment, based on Embodiment 1, further defines the specific structure of the signal transmission layer 5 and its connection relationship with the isolation line 6. Specifically, the signal transmission layer 5 is a metal trace layer, which includes metal traces arranged around the periphery of the ITO electrode layer 2, and the isolation line 6 is electrically connected to the metal traces.

[0037] In this embodiment, the metal trace layer is typically made of a low-resistivity conductive material, such as a molybdenum-aluminum-molybdenum three-layer composite structure, pure copper, or silver paste circuitry. Its main function is to enable signal transmission between the ITO electrode layer 2 and the external driving circuit. The metal traces are arranged around the perimeter of the ITO electrode layer 2, forming a surrounding conductive frame. Unlike the isolation line 6 in Embodiment 1 or Embodiment 2, which only serves as a physical barrier, the key improvement in this embodiment is that the isolation line 6 is electrically connected to the metal traces. This connection method extends the function of the isolation line 6 from simple "physical isolation" to "electrical conduction."

[0038] From a working mechanism perspective, since the metal traces are typically connected to the ground terminal or a specific potential reference terminal of the driver IC, when the isolation line 6 is electrically connected to the metal trace, the potential of the isolation line 6 will be clamped to the ground potential or reference potential. When electrostatic charge or abnormal current attempts to enter the ITO main channel 3, the isolation line 6, located on one side of the main channel, can act like a "lightning rod," actively capturing these charges and quickly dissipating them to the ground terminal through the metal traces connected to it. This active electrostatic protection mechanism, compared to simple physical blocking, can more effectively eliminate the potential for electrostatic accumulation around the ITO main channel 3, greatly reducing the risk of short circuits caused by high-voltage breakdown in the ITO main channel 3. It should be understood that the connection between the isolation line 6 and the metal trace can be direct contact or indirect connection through vias or conductive adhesive, as long as an effective electrical path can be formed.

[0039] Example 4:

[0040] This embodiment, based on the above embodiments, specifically defines the array architecture of the electrode layer and the material properties of the insulating layer 4. Specifically, the ITO electrode layer 2 is an X-channel electrode array, and the signal transmission layer 5 is a Y-channel electrode array. This structure, where X and Y channels are interleaved, is the mainstream architecture for multi-touch in capacitive touchscreens. In this architecture, the isolation line 6 is typically located at the edge of each channel in the X-channel or Y-channel electrode array. For example, when the isolation line 6 is located at the edge of the X-channel, it effectively prevents electrical crosstalk between the X-channel and the adjacent Y-channel caused by film breakage or electrostatic accumulation, ensuring the independence and accuracy of the X-axis and Y-axis sensing signals.

[0041] Furthermore, the insulating layer 4 is an OC insulating layer 4, which fully covers the ITO electrode layer 2.

[0042] Here, OC typically refers to photoresist or organic insulating resin material. Compared to traditional inorganic insulating layers 4 such as silicon dioxide, the OC insulating layer 4 has superior leveling properties, enabling the formation of a highly smooth surface. Specifically, due to the microscopic steps formed by the etching process on the surface of the ITO electrode layer 2, insufficient smoothness of the insulating layer 4 can easily lead to electric field distortion at the edge of the steps, thereby causing tip discharge or insulation breakdown. This embodiment uses the OC insulating layer 4, which, with its high dielectric constant and good film-forming properties, can not only fill the microscopic unevenness of the surface and eliminate potential discharge hazards, but also provide a smooth and reliable substrate for the upper signal transmission layer 5. It should be understood that the full coverage characteristic of the OC insulating layer 4 and the isolation line 6 form a dual protection mechanism: the isolation line 6 blocks the conductive path in the horizontal direction, while the OC insulating layer 4 provides electrical isolation in the vertical direction. The two work together to significantly improve the overall structure's withstand voltage and short-circuit protection reliability.

[0043] Example 5:

[0044] This embodiment further optimizes the microstructure between the isolation line 6 and the ITO main channel 3 based on the above embodiment. Specifically, it also includes a filling insulation layer 9 disposed between the isolation line 6 and the ITO main channel 3, which fills the step gap between the isolation line 6 and the ITO main channel 3.

[0045] In specific processing techniques, especially when laser etching is used to form the isolation line 6, the laser beam removes some ITO material to form non-conductive trenches. This process inevitably creates microscopic steps or groove structures between the edge of the ITO main channel 3 and the sidewall of the isolation line 6, which is the "step gap" described in this embodiment. If this step gap is not treated, it can easily become a "fouling place" during the production process, accumulating conductive particles or dust; at the same time, the sharp step edges are prone to electric field distortion under the action of an electric field, causing point discharge, thus creating a potential short circuit.

[0046] This embodiment introduces a filling insulating layer 9, utilizing the excellent leveling and filling properties of the insulating material to completely fill the aforementioned step gap. Specifically, the filling insulating layer 9 can be made of the same or similar material as the insulating layer 4, such as photoresist or polyimide resin, and is applied through a coating process to penetrate and cover the gap. This design eliminates the recessed area at the microstructure level, making the surface between the isolation line 6 and the ITO main channel 3 more flat. This not only effectively prevents the accumulation of conductive foreign matter at the gap but also eliminates the inducement for tip discharge, thereby significantly improving the electrical reliability and production yield of the capacitive touchscreen in complex environments.

[0047] Example 6:

[0048] This embodiment provides a capacitive touchscreen. The capacitive touchscreen includes the short-circuit protection structure for the ITO circuitry of the capacitive screen described in any one of embodiments 1 to 5 above.

[0049] Specifically, the capacitive touchscreen described in this embodiment, as a complete product entity, includes not only the core short-circuit protection structures such as the substrate 1, ITO electrode layer 2, insulating layer 4, signal transmission layer 5, and isolation circuit 6 described in detail in the preceding embodiments, but also other necessary functional components to achieve complete touch interaction functionality. For example, the capacitive touchscreen also includes a cover plate covering the signal transmission layer 5, which is typically made of tempered glass or transparent polymer material to protect the internal film structure and provide a flat touch surface. Furthermore, the touchscreen also includes a flexible circuit board electrically connected to the signal transmission layer 5. This FPC is used to transmit the touchscreen's sensing signals to an external main control chip or processor.

[0050] In the product architecture of this embodiment, the aforementioned short-circuit protection structure, particularly the connection between the isolation line 6 and the metal trace layer, effectively forms an electrical conduction path with the FPC's grounding line. When a user touches the cover plate and generates static electricity, or when equipment generates static electricity during production and assembly and attempts to penetrate the ITO main channel 3, the isolation line 6 can perform its dual functions of physical blocking and static discharge, ensuring that the touchscreen maintains high sensitivity and high reliability even in complex application environments. It should be understood that the capacitive touchscreen in this embodiment can be in various forms, such as a mobile phone touchscreen, a tablet computer touchscreen, an automotive touchscreen, or an industrial control touchscreen. As long as it integrates the aforementioned short-circuit protection structure, it falls within the protection scope of this invention.

[0051] In the description of this specification, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0052] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0053] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A short-circuit protection structure for ITO circuitry of a capacitive touchscreen, characterized in that, It includes a substrate (1), an ITO electrode layer (2), an insulating layer (4), and a signal transmission layer (5), wherein, The ITO electrode layer (2) is disposed on the top of the substrate (1), and at least one ITO main channel (3) is provided on the ITO electrode layer (2), and an isolation line (6) is provided on one side of the ITO main channel (3). The insulating layer (4) is disposed on top of the ITO electrode layer (2); The signal transmission layer (5) is disposed on top of the insulating layer (4).

2. The short-circuit protection structure for ITO circuits of a capacitive touchscreen according to claim 1, characterized in that, The isolation line (6) includes a first laser isolation line (7) and a second laser isolation line (8). The first laser isolation line (7) and the second laser isolation line (8) are respectively disposed on both sides of the ITO main channel (3) and have a preset distance between them.

3. The short-circuit protection structure for ITO circuits of a capacitive touchscreen according to claim 2, characterized in that, The width of the first laser isolation line (7) and the second laser isolation line (8) is 0.1 mm to 0.4 mm.

4. The short-circuit protection structure for ITO circuits of a capacitive touchscreen according to claim 1, characterized in that, The signal transmission layer (5) is a metal trace layer, which includes metal traces arranged around the periphery of the ITO electrode layer (2), and the isolation line (6) is electrically connected to the metal traces.

5. The short-circuit protection structure for ITO circuits of a capacitive touchscreen according to claim 1, characterized in that, The ITO electrode layer (2) is an X-channel electrode array, and the signal transmission layer (5) is a Y-channel electrode array.

6. The short-circuit protection structure for ITO lines of a capacitive touchscreen according to claim 5, characterized in that, The Y-channel electrode array includes multiple electrode units and an ITO bridging layer connecting adjacent electrode units. The ITO bridging layer is disposed above the insulating layer (4), and the isolation line (6) is disposed in the gap between adjacent ITO main channels (3).

7. The short-circuit protection structure for ITO circuits of a capacitive touchscreen according to claim 1, characterized in that, The insulating layer (4) is an OC insulating layer (4), which fully covers the ITO electrode layer (2).

8. The short-circuit protection structure for ITO circuits of a capacitive touchscreen according to claim 1, characterized in that, It also includes a filling insulation layer (9) disposed between the isolation line (6) and the ITO main channel (3), the filling insulation layer (9) being used to fill the step gap between the isolation line (6) and the ITO main channel (3).

9. A capacitive touchscreen, characterized in that, Including the short-circuit protection structure for ITO lines of the capacitive touchscreen as described in any one of claims 1 to 8.

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