Anti-interference flexible circuit board and touch screen

Abstract

The application relates to an anti-interference flexible circuit board and a touch screen, wherein the anti-interference flexible circuit board comprises a circuit board base material and a ground shielding layer arranged on the circuit board base material; a sensor signal line arranged on the circuit board base material and used for transmitting a touch sensing signal; the ground shielding layer is arranged on at least one side of an area where the sensor signal line is located; the ground shielding layer comprises a mesh ground copper and a solid copper ground wire block, and the solid copper ground wire block is arranged in a range where the sensor signal line and a high-frequency interference source spatially overlap. Through the anti-interference flexible circuit board in the application, a good interference shielding effect can be formed, the structure of the mesh ground copper and the solid copper ground wire block can well balance the softness of the flexible circuit board, and meanwhile, the integrity of the ground shielding layer can be ensured. Meanwhile, through the arrangement of the solid copper ground wire block, heat can be quickly dispersed to the whole ground shielding layer, the heat dissipation effect is better than that of the mesh ground copper structure, and the stable operation of the flexible circuit board is ensured.

Description

Technical Field

[0001] This application relates to the field of flexible circuit board technology, and more specifically, to an anti-interference flexible circuit board and a touch screen. Background Technology

[0002] As laptops become increasingly thinner and lighter, related components are being streamlined and compressed to fit the limited space of the entire device. For example, the space of the flexible circuit board connecting the touch screen and the touch screen printed circuit board is often compressed to the limit. Under the streamlined solution, it is difficult to meet the safety distance of non-overlapping between signal lines and high-frequency components such as inductors and antennas. The lack of effective distance between signal lines and interference sources can easily cause noise to exceed the limit, thereby affecting the hover control and active pen performance.

[0003] According to the design requirements of flexible circuit boards, a grid of ground copper needs to be laid on the top and bottom layers of the flexible circuit board to facilitate the establishment of a ground shielding layer. This shielding can block some external electromagnetic interference (EMI) and ESD protection. To improve the anti-interference of the overlap between the flexible circuit board and the high-frequency components of the LCM, the optimization of the circuit layout and the ground copper shielding layer is indispensable. Utility Model Content

[0004] The purpose of this application is to provide an anti-interference flexible circuit board and touch screen that can outperform the shielding effect of existing grid copper, while taking into account the flexibility of the flexible circuit board and ensuring the integrity of the shielding layer.

[0005] To achieve the above objectives, in a first aspect, the present invention provides an anti-interference flexible circuit board, the flexible circuit board comprising a circuit board substrate and a grounding shielding layer disposed on the circuit board substrate; Sensor signal lines are arranged on the circuit board substrate and are used to transmit touch sensing signals; The grounding shielding layer is disposed on at least one side of the area where the sensor signal line is located; The grounding shield layer includes a grid of copper ground and solid copper ground blocks, with the solid copper ground blocks arranged within the area where the sensor signal lines and high-frequency interference sources spatially overlap.

[0006] In an optional implementation, the solid copper ground block completely covers the projection area of ​​the high-frequency interference source on the flexible circuit board.

[0007] In an optional implementation, the boundary of the solid copper ground block extends outward from the projected area by at least 0.5 mm on one side.

[0008] In an optional embodiment, the grid ground copper is disposed around the solid copper ground block, and the solid copper ground block and the area where the grid ground copper is located together constitute a grounding shielding layer on one side of the circuit board substrate.

[0009] In an optional embodiment, the sensor signal line is disposed on the side of the circuit board substrate away from the high-frequency interference source.

[0010] In an optional embodiment, the circuit board substrate is provided with through holes, which are located on the circumferential periphery of the projection area and are at least spaced away from the edge of the projection area. The through-hole is used to allow the sensor signal line to pass through and be led to the side of the circuit board substrate away from the high-frequency interference source.

[0011] In an optional embodiment, the grounding shield layer further includes a grid ground copper layer, which is laid across the circuit board substrate on the other side of the solid copper ground block and the grid ground copper grounding shield layer.

[0012] In an optional implementation, the outline shape of the solid copper ground block is adapted to correspond to the outline shape of the projected area.

[0013] In an optional implementation, the high-frequency interference source includes an inductive element or an antenna element.

[0014] Secondly, the present invention provides a touch screen, including a touch screen sensor, a main control circuit board, and an anti-interference flexible circuit board as described in any of the foregoing embodiments, wherein the anti-interference flexible circuit board is connected between the touch screen sensor and the main control circuit board.

[0015] The anti-interference flexible circuit board in this application can form a good interference shielding effect. The structure of the grid ground copper and solid copper ground wire block can well balance the flexibility of the flexible circuit board and ensure the integrity of the grounding shielding layer.

[0016] Meanwhile, by setting up solid copper ground blocks, heat can be quickly dispersed to the entire grounding shield layer, and the heat dissipation effect is better than that of the grid ground copper structure, ensuring the stable operation of the flexible circuit board.

[0017] Other features and advantages of this application will be described in detail in the following detailed description section. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the structure of the flexible circuit board grid ground copper shielding layer in this application; Figure 2 This is a schematic diagram of the structure of a grid ground copper and solid copper ground block shielding layer of a flexible circuit board in this application; Figure 3 This is a schematic diagram of another type of grid ground copper and solid copper ground block shielding layer for flexible circuit boards in this application.

[0020] icon: 1-Circuit board substrate; 2-Sensor signal line; 3-Grid ground copper; 4-Solid copper ground block; 5-High frequency interference source. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0022] In the description of this application, it should be noted that the terms "inner" and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use. They are used only for the convenience of describing this application and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0023] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "setup" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0024] The anti-interference flexible circuit board in this application mainly improves the shielding effect of the existing grid ground copper by optimizing the grounding shielding structure, thereby reducing the interference of high-frequency components to the flexible circuit board.

[0025] See Figure 1 and combined Figures 2-3 The anti-interference flexible circuit board of this utility model has a main structure including a circuit board substrate 1, a sensor signal line 2, and a grounding shielding layer arranged on the circuit board substrate 1.

[0026] The circuit board substrate 1 is made of flexible materials such as polyimide, and the sensor signal line 2 is arranged on the top and / or bottom layer of the circuit board substrate 1 to transmit signals from the touch screen sensor. A grounding shielding layer is provided on at least one side of the area where the sensor signal line 2 is located to shield against external high-frequency interference.

[0027] Based on the main improvement direction of preventing high-frequency interference, the grounding shield layer includes a grid ground copper 3 and a solid copper ground block 4. The grid ground copper 3 area is laid throughout most of the circuit board substrate 1 to maintain the flexibility of the flexible circuit board.

[0028] The solid copper ground block 4 is arranged in the area where the sensor signal line 2 and the high-frequency interference source 5 overlap, so that the solid copper ground block 4 can provide stronger local shielding. In particular, for high-frequency interference sources 5 such as inductors or antennas that can generate high-frequency interference signals, the solid copper ground block 4 can avoid the interference of high-frequency interference signals on the operation of the flexible circuit board to the greatest extent, thus forming an effective protection for the flexible circuit board.

[0029] By combining the flexibility of the mesh ground copper 3 with the strong shielding performance of the solid copper ground, and optimizing the signal path at the wiring layer, the high-frequency signal interference can be effectively suppressed while ensuring the flexibility of the flexible circuit board, thereby improving the signal-to-noise ratio of the touch sensing signal and the stability of the active pen performance.

[0030] In order to avoid interference caused by the high-frequency signal emitted by the high-frequency interference source 5, the solid copper ground block 4 completely covers the projection area of ​​the high-frequency interference source 5 on the flexible circuit board. By using the solid copper ground block 4 to cover the key area where the signal line overlaps with the high-frequency interference source 5, compared with the traditional full-grid ground copper 3, a continuous, low-impedance shielding layer is provided, which significantly enhances the local electromagnetic interference (EMI) immunity.

[0031] Combination Figure 2 Preferably, the boundary of the solid copper ground block 4 extends outward by at least 0.5 mm on one side from the edge of the projection area. That is, if the projection area of ​​the high-frequency interference source 5 on the flexible circuit board is a square with a side length of 2 mm, under the premise that the solid copper ground block 4 coincides with the center of the projection area, the solid copper ground block 4 should be a square covering area with a side length of at least 3 mm, so as to eliminate alignment error and prevent interference leakage of the edge field.

[0032] Combination Figure 3 In another practical configuration, the solid copper ground block 4 includes a complete elongated block area located on the non-folded part of the flexible circuit board, with the length being the same as the width of the corresponding part of the flexible circuit board, which can reduce the risk of cracks caused by bending.

[0033] In this application, the grounding shielding layer is disposed on both sides in the thickness direction of the circuit board substrate 1. That is, the grounding shielding layer is covered on both sides of the circuit board substrate 1. Specifically, one side of the grounding shielding layer includes a continuous grid of ground copper 3, while the other side is provided with a grounding shielding layer composed of solid copper ground wire blocks 4 and grid of ground copper 3.

[0034] Specifically, on the side where the solid copper ground block 4 is located, the grid ground copper 3 is located around the solid copper ground block 4. The area where the solid copper ground block 4 and the grid ground copper 3 are located together constitutes the grounding shielding layer of the circuit board substrate 1 facing the high-frequency interference source 5, which can reduce the impact of high-frequency interference signals to the minimum.

[0035] This configuration allows for high-strength shielding in key local areas of the high-frequency interference source 5 using solid copper ground, while maintaining the overall flexibility of the flexible circuit board through the surrounding grid copper ground 3, facilitating bending and wiring in confined spaces.

[0036] Based on the arrangement of sensor signal lines 2 on the circuit board substrate 1, different routing forms are included depending on the specific structure.

[0037] In one preferred embodiment, the sensor signal line 2 is disposed on the side of the circuit board substrate 1 facing away from the high-frequency interference source 5, and the wiring side of the sensor signal line 2 on the circuit board substrate 1 is covered with a grid ground copper 3. At the same time, a grid ground copper 3 and a solid copper ground block 4 are disposed on the side of the circuit board substrate 1 facing the high-frequency interference source 5.

[0038] Specifically, if the high-frequency interference source 5 is located at the bottom of the flexible circuit board, then the sensor signal line 2 should be preferentially placed on the top layer of the flexible circuit board, and the grounding shield layer formed by the solid copper ground block 4 and the grid ground copper 3 should be placed on the top layer of the flexible circuit board.

[0039] In another implementation, taking the high-frequency interference source 5 located at the bottom of the flexible circuit board as an example, if a routing conflict occurs, the sensor signal line 2 can only run on the bottom layer. After avoiding the conflict, a hole is drilled before entering the projection area of ​​the signal interference on the bottom layer, and then the sensor signal line 2 is moved to the top layer for routing to increase the physical distance from the high-frequency interference source 5. By setting through holes on the circuit board substrate 1, and combining the through holes being located on the circumferential periphery of the projection area, and leaving at least a space distance from the edge of the projection area, it is possible to facilitate the outward wrapping of the sensor signal line 2.

[0040] Furthermore, the through hole is used to allow the sensor signal line 2 to pass through the circuit board substrate 1 and be led to the side of the circuit board substrate 1 away from the high-frequency interference source 5, thereby achieving the above-mentioned technical effect of increasing the physical distance from the high-frequency interference source 5.

[0041] Based on the grounding shielding layer formed by the solid copper ground block 4 and the grid ground copper 3, by setting a grid ground copper 3 layer that is laid on the other side of the circuit board substrate 1, which together form the power shielding layer, a double-layer grounding shielding layer can be formed on both sides of the flexible circuit board, so as to maximize the shielding effect.

[0042] The outline shape of the solid copper ground block 4 can be adapted to correspond to the outline shape of the projected area. For example, when the high-frequency interference source 5 is a rectangular inductor, the solid copper ground area can be designed as a rectangle.

[0043] If space is limited, it can also be designed as a rhombus, circle or other irregular shape to maximize the use of the shielding area and ensure complete isolation and coverage of the projection area.

[0044] In this application, the anti-interference flexible circuit board has a shielding effect that is far superior to that of the grid ground copper 3 under the same size conditions. The grid ground copper 3 shielding is composed of copper wire intersections, which results in a longer and discontinuous current path, which can easily increase the risk of signal crosstalk. The solid copper ground block 4 is a complete and continuous area, and its large-area solid structure can effectively shield external interference and form better protection.

[0045] The combination of the grid ground copper 3 and the solid copper ground block 4 can balance the flexibility of the flexible circuit board with the integrity of the shielding layer.

[0046] The solid copper ground block 4 can quickly disperse heat across the entire grounding shield plane, indirectly improving heat dissipation. Simultaneously, as a "common ground reference point" for the circuit, the solid copper ground block 4 provides a lower impedance return path for signals, ensuring stable potential at each node in the circuit, thereby achieving timely ESD discharge.

[0047] In the traditional grid-like copper 3 structure, the unevenness of the grid surface can easily lead to uneven QR code spraying on flexible circuit boards. The solid copper ground block 4 can effectively solve the QR code scanning and recognition problem caused by abnormal spraying.

[0048] This application also provides a touch screen, including a touch screen sensor, a main control circuit board, and the anti-interference flexible circuit board described above. The anti-interference flexible circuit board is connected between the touch screen sensor and the main control circuit board, which can effectively solve the problem of sensor signal interference from high-frequency interference source 5 under the thin and light design, and significantly improve the accuracy and stability of Hover (free-flying control) and active pen operation.

[0049] It should be noted that, where there is no conflict, the features in the embodiments of this application can be combined with each other.

[0050] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. An anti-interference flexible circuit board, characterized in that, The flexible circuit board includes a circuit board substrate and a grounding shielding layer disposed on the circuit board substrate; Sensor signal lines are arranged on the circuit board substrate and are used to transmit touch sensing signals; The grounding shielding layer is disposed on at least one side of the area where the sensor signal line is located; The grounding shield layer includes a grid of copper ground and solid copper ground blocks, with the solid copper ground blocks arranged within the area where the sensor signal lines and high-frequency interference sources spatially overlap.

2. The anti-interference flexible circuit board according to claim 1, characterized in that, The solid copper ground block completely covers the projection area of ​​the high-frequency interference source on the flexible circuit board.

3. The anti-interference flexible circuit board according to claim 2, characterized in that, The boundary of the solid copper ground block extends outward from the projected area by at least 0.5 mm on one side.

4. The anti-interference flexible circuit board according to claim 2, characterized in that, The grid ground copper is disposed around the solid copper ground block, and the solid copper ground block and the area where the grid ground copper is located together constitute a grounding shielding layer on one side of the circuit board substrate.

5. The anti-interference flexible circuit board according to claim 2, characterized in that, The sensor signal line is located on the side of the circuit board substrate away from the high-frequency interference source.

6. The anti-interference flexible circuit board according to claim 2, characterized in that, The circuit board substrate is provided with through holes, which are located on the circumferential periphery of the projection area and are at least spaced away from the edge of the projection area. The through-hole is used to allow the sensor signal line to pass through and be led to the side of the circuit board substrate away from the high-frequency interference source.

7. The anti-interference flexible circuit board according to claim 1, characterized in that, The grounding shielding layer also includes a grid ground copper layer, which is laid on the other side of the circuit board substrate opposite to the solid copper ground block and the grid ground copper grounding shielding layer.

8. The anti-interference flexible circuit board according to claim 2, characterized in that, The outline shape of the solid copper ground block is adapted to correspond to the outline shape of the projected area.

9. The anti-interference flexible circuit board according to any one of claims 1-8, characterized in that, The high-frequency interference source includes inductive elements or antenna elements.

10. A touchscreen, characterized in that, The device includes a touchscreen sensor, a main control circuit board, and an anti-interference flexible circuit board as described in any one of claims 1-9, wherein the anti-interference flexible circuit board is connected between the touchscreen sensor and the main control circuit board.

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