Double-layer flexible touch circuit board structure and touch products

Abstract

The present invention discloses a double-layer flexible touch circuit board structure and a touch product, which relates to the technical field of capacitive touch panels and pressure sensors, and solves the technical problems that the three-layer flexible touch circuit board is not easy to bend, has a high manufacturing cost, and has a relatively complex manufacturing process. The touch structure includes: a top layer FPC and a bottom layer FPC, the top layer FPC is provided with a first touch sensing electrode block, the bottom layer FPC is provided with a second touch sensing electrode block, and touch channel routing or copper sheet laying is performed; an electromagnetic shielding layer is provided on the bottom layer FPC, and the electromagnetic shielding layer is used to complete the shape missing part of the second touch sensing electrode block due to touch channel routing or copper sheet laying, so as to obtain a complete second touch sensing electrode block. The present invention reduces the number of layers of the circuit from three layers to two layers, and at the same time, an electromagnetic shielding layer is provided to complete the shape missing part of the second touch sensing electrode block, thereby increasing softness, improving the light pinch pressure sensing experience, and reducing manufacturing costs.

Description

Technical Field

[0001] The present invention relates to the technical field of capacitive touch panels and pressure sensors, and in particular to a double-layer flexible touch circuit board structure and a touch product. Background Art

[0002] With the development of electronic technology and the improvement of user experience requirements, the simple PCB (Printed Circuit Board) capacitive touch panel has a single touch form and lacks novelty, which can no longer meet the use needs. As a result, FPC (Flexible Printed Circuit) capacitive touch panels have emerged. FPC flexible circuit boards have the characteristics of high wiring density, light weight, thin thickness, three-dimensional wiring, and bendability. They have advantages that other types of circuit boards cannot match. They are used more and more widely for short-range wireless communication between mobile devices, consumer PC products, and smart control tools.

[0003] At present, the capacitive touch panel is used to realize the light pinch pressure sensing function of the pressure sensor, and a flexible multi-layer FPC is mostly used. In order to realize the integrity of the first and third layers of the sensing surface electrodes and ensure the convenience and simplicity of the touch channel routing space, the existing flexible multi-layer FPC has a three-layer structure. Figure 1-Figure 3 As shown, the first layer is equipped with multiple touch sensing electrode blocks, the second layer (middle layer) is equipped with touch channel connection wiring, and the third layer is equipped with multiple touch sensing electrode blocks, which are then bonded with foam and grounded metal. When a finger softly pinches the touch surface, the foam deformation approaches the internal grounded metal shell to form a change in the plate capacitance parameter, and the change in capacitance value is converted into a light pinch pressure sensing function.

[0004] However, since the first and third layers are completely arranged sensing electrode blocks, the sensing electrode blocks are designed as copper blocks, which makes the overall surface of the FPC hard and difficult to bend. At the same time, the cost of the three-layer design is higher than that of the double-sided board, and the manufacturing process is relatively complicated and the production period is long. As a result, the three-layer FPC capacitive touch panel is difficult to produce and it is difficult to improve the light pinch pressure sensing experience.

[0005] In the process of implementing the present invention, the inventors found that there are at least the following problems in the prior art:

[0006] The three-layer flexible touch circuit board is not easy to bend, has a high production cost and a complex production process, making it difficult to improve the light pinch pressure sensing experience. Summary of the invention

[0007] The purpose of the present invention is to provide a double-layer flexible touch circuit board structure and a touch product to solve the technical problems in the prior art that the three-layer flexible touch circuit board is not easy to bend, has a high manufacturing cost, and a complex manufacturing process, which affects the application of the flexible touch circuit board. The preferred technical solutions among the many technical solutions provided by the present invention can produce many technical effects as described below.

[0008] To achieve the above object, the present invention provides the following technical solutions:

[0009] The present invention provides a method for realizing a double-layer flexible touch circuit board, which includes the following steps. S100: Arrange a plurality of first touch sensing electrode blocks on a first FPC substrate, and set a first sensing hole to form a top layer FPC; S200: Arrange a plurality of second touch sensing electrode blocks corresponding to the first touch sensing electrode blocks on a second FPC substrate, set a second sensing hole, electrically connect the first sensing hole and the second sensing hole, and perform touch channel routing or copper laying to form a bottom layer FPC corresponding to the shape of the top layer FPC; S300: Arrange an electromagnetic shielding layer on the bottom layer FPC, and the electromagnetic shielding layer is used to complete the shape missing part of the second touch sensing electrode block caused by touch channel routing or copper laying to form a complete second touch sensing electrode block; S400: Arrange a window hole in the electromagnetic shielding layer, and electrically connect the electromagnetic shielding layer to the touch channel routing or copper laying through the window hole to realize pressure sensing and light pinch pressure sensing.

[0010] Preferably, the steps S300 and S400 are replaced by: S300': within one detection cycle, all groups of touch channels simultaneously emit waveforms with the same voltage, the same timing and the same frequency; S400': based on the fact that there is no voltage difference between any two groups of touch channels at any time, the coupling capacitance between different groups of touch channels is eliminated; S500': based on the capacitance formed between the first touch sensing electrode block, the second touch sensing electrode block and the grounded metal shell, the magnitude of the light pinching pressure on the double-layer flexible touch circuit board is obtained by detecting the capacitance change.

[0011] Preferably, the touch channel wiring is evenly arranged between the intersection gaps of a plurality of the second touch sensing electrode blocks, so as to reduce the space occupied by the second touch sensing electrode blocks and reduce the thickness of the bottom FPC.

[0012] A double-layer flexible touch circuit board structure is used to implement the above-mentioned double-layer flexible touch circuit board implementation method, comprising a top FPC and a bottom FPC, wherein the top FPC is provided with a first touch sensing electrode block, the bottom FPC is provided with a second touch sensing electrode block, and touch channel routing or copper sheet laying is performed; an electromagnetic shielding layer is provided on the bottom FPC, and the electromagnetic shielding layer is used to complete the shape missing part of the second touch sensing electrode block caused by touch channel routing or copper sheet laying, so as to obtain a complete second touch sensing electrode block; the electromagnetic shielding layer comprises a first covering film, a conductive layer and a second covering film; the first covering film and the second covering film are arranged on both sides of the conductive layer, and are both used for insulation.

[0013] Preferably, it also includes compressed foam and a grounded metal sheet, the compressed foam is connected to the bottom layer FPC, and the grounded metal sheet is connected to the compressed foam; the top layer FPC, compressed foam, and grounded metal sheet form a capacitor for sensing sliding touch operations, and the bottom layer FPC, compressed foam, and grounded metal sheet form a capacitor for sensing light pinching operations.

[0014] Preferably, the electromagnetic shielding layer is in a U-shape or an E-shape, and the electromagnetic shielding layer is printed on the surface of the bottom FPC by silk-screen printing.

[0015] Preferably, the first covering film is connected to the surface of the bottom FPC, and the window hole is arranged on the first covering film.

[0016] Preferably, the window hole is spaced apart from the first sensing hole and the second sensing hole; the number of the window holes is multiple, and the window holes are round holes or square holes.

[0017] Preferably, the first covering film and the second covering film are both PI covering films.

[0018] A touch product comprises the double-layer flexible touch circuit board structure described in any one of the above items.

[0019] Implementing one of the above technical solutions of the present invention has the following advantages or beneficial effects:

[0020] This application does not change the structural function of the existing flexible touch circuit board. The double-layer flexible touch circuit board is a double-layer design of the top FPC and the bottom FPC, reducing the number of layers of the existing circuit from three to two. At the same time, an electromagnetic shielding layer is set to supplement the missing part of the shape of the second touch sensing electrode block caused by the wiring of the bottom FPC, so that the touch sensing sensitivity of the double-layer flexible touch circuit board is not affected. The double-layer design reduces the thickness of the FPC, increases its softness, and improves the light pinch pressure sensing experience. At the same time, the electromagnetic shielding layer has a simple process and is easy to manufacture, which can reduce the overall manufacturing cost by more than 30%. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. It is obvious that the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0022] Figure 1 This is a schematic diagram of the first layer structure of an existing three-layer flexible touch circuit board;

[0023] Figure 2 It is a schematic diagram of the second layer structure of an existing three-layer flexible touch circuit board;

[0024] Figure 3 It is a schematic diagram of the third layer structure of an existing three-layer flexible touch circuit board;

[0025] Figure 4 is a flow chart of a method for implementing a double-layer flexible touch circuit board according to a first embodiment of the present invention;

[0026] Figure 5 Schematic diagram of a cross section of a double-layer flexible touch circuit board in a double-layer flexible touch circuit board method according to an embodiment of the present invention Figure 1 ;

[0027] Figure 6 Schematic diagram of a cross section of a double-layer flexible touch circuit board in a double-layer flexible touch circuit board method according to an embodiment of the present invention Figure 2 ;

[0028] Figure 7 This is a schematic diagram of the first circuit structure in the method of double-layer flexible touch circuit board in the embodiment of the present invention. Figure 1 ;

[0029] Figure 8 This is a schematic diagram of the first circuit structure in the method of double-layer flexible touch circuit board in the embodiment of the present invention. Figure 2 ;

[0030] Fig. 9 This is a schematic diagram of the first circuit structure in the method of double-layer flexible touch circuit board in the embodiment of the present invention. Figure 3 ;

[0031] Fig.10 This is a schematic diagram of the second circuit structure in the method for double-layer flexible touch circuit board in the embodiment of the present invention. Figure 1 ;

[0032] Fig.11 This is a schematic diagram of the second circuit structure in the method for double-layer flexible touch circuit board in the embodiment of the present invention. Figure 2;

[0033] Fig.12 This is a schematic diagram of the second circuit structure in the method for double-layer flexible touch circuit board in the embodiment of the present invention. Figure 3 ;

[0034] Fig.13 is a flow chart of a method for implementing a double-layer flexible touch circuit board according to a second embodiment of the present invention;

[0035] Fig.14 The circuit structure of the double-layer flexible touch circuit board method in the second embodiment of the present invention is shown in FIG. Figure 1 ;

[0036] Fig.15 The circuit structure of the double-layer flexible touch circuit board method in the second embodiment of the present invention is shown in FIG. Figure 2 ;

[0037] Fig.16 This is a working principle diagram of self-capacitance detection in a double-layer flexible touch circuit board method according to a second embodiment of the present invention;

[0038] Fig.17 It is a schematic diagram of touch channel waveforms of the circuit structure in the double-layer flexible touch circuit board method according to the second embodiment of the present invention. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solutions and advantages of the present invention clearer, the various exemplary embodiments to be described below will refer to the corresponding drawings, which constitute a part of the exemplary embodiments, wherein various exemplary embodiments that may be used to implement the present invention are described. Unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementation methods described in the following exemplary embodiments do not represent all implementation methods consistent with the present disclosure. It should be understood that they are only examples of processes, methods, devices, etc. that are consistent with some aspects of the present disclosure as detailed in the attached claims, and other embodiments may also be used, or the embodiments listed herein may be modified in structure and function without departing from the scope and essence of the present invention.

[0040] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", etc. indicate the orientation or positional relationship based on the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the elements referred to must have a specific orientation, be constructed and operated in a specific orientation. The terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. The term "multiple" means two or more. The terms "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, an integral connection, a mechanical connection, an electrical connection, a communication connection, a direct connection, an indirect connection through an intermediate medium, and can be the internal connection of two elements or the interaction relationship between two elements. The term "and / or" includes any and all combinations of one or more related listed items. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0041] In order to illustrate the technical solution of the present invention, a specific embodiment is used below for description, and only the parts related to the embodiment of the present invention are shown.

[0042] Embodiment 1:

[0043] like Figure 4-Figure 12As shown, the present invention provides a method for realizing a double-layer flexible touch circuit board, including the following steps. S100: Arrange a plurality of first touch sensing electrode blocks on a first FPC substrate. The specific arrangement method may adopt the existing technology. The plurality of first touch sensing electrode blocks are generally distributed in an array, and a first sensing hole is set. The first sensing hole is set on the first touch sensing electrode block to form a top layer FPC. Of course, the top layer FPC also needs to arrange touch sensing elements and carry out touch sensing element routing to realize the touch sensing function. The top layer FPC is a surface sliding touch functional surface. S200: Arrange a plurality of second touch sensing electrode blocks corresponding to the first touch sensing electrode blocks on a second FPC substrate. The specific arrangement method may adopt the existing technology. The second touch sensing electrode blocks correspond to the first touch sensing electrode blocks in overall shape and position, thereby facilitating the overall structural design of the double-layer flexible touch circuit board. A second sensing hole is also set, and the positions of the first sensing hole and the second sensing hole correspond to each other for the convenience of wiring. The first sensing hole and the second sensing hole are electrically connected, and the touch channel wiring or copper foil is laid, and then connected to the touch chip and MCU to detect the change in capacitance value, that is, the touch channel wiring or the copper foil is electrically connected to the first sensing hole and the second sensing hole to form a bottom FPC corresponding to the shape of the top FPC, that is, the shapes of the top FPC and the bottom FPC are basically the same, and the bottom FPC is a pressure sensing functional surface for sensing the strength of light pinch pressure. Due to the space occupied by the touch channel wiring or the copper foil laying on the bottom FPC, the second touch sensing electrode block will have part of its shape missing, which will affect the sensitivity of the entire double-layer flexible touch circuit board to light pinch pressure sensing. Of course, in order to realize the light pinch pressure sensing function, the bottom FPC also needs to be equipped with touch sensing elements and the touch sensing elements need to be routed. S300: An electromagnetic shielding layer is set on the bottom FPC. Specifically, the electromagnetic shielding layer is located on the lower surface of the entire double-layer flexible touch circuit board. The electromagnetic shielding layer can be fixed to the bottom FPC by gluing or other means. Since the electromagnetic shielding layer includes a conductive layer, it can be equivalent to the copper foil of the touch sensing electrode block, so the electromagnetic shielding layer is used to complete the shape missing part of the second touch sensing electrode block due to the touch channel routing or the laying of copper foil, that is, the electromagnetic shielding layer and the second touch sensing electrode block in S200 together form a complete second touch sensing electrode block, thereby ensuring the sensitivity of the double-layer flexible touch circuit board to light pinching and pressure sensing. At the same time, the addition of the electromagnetic shielding layer can cover the routing on the surface of the bottom FPC to form a shielding layer, which can prevent the routing from being interfered by external signals and improve the sensitivity and reliability of signal transmission.S400: A window hole is set in the electromagnetic shielding layer so that the cover film that needs to be connected to the upper layer of the copper sheet can be contacted and connected through the window hole, and the electromagnetic shielding layer is connected to the touch channel wiring or the copper sheet through the window hole, so that the electromagnetic shielding layer is electrically connected to the bottom FPC, thereby completing the second touch sensing electrode block and increasing the sensing functional surface of the second touch sensing electrode block to achieve pressure sensing and light pinch pressure sensing, so as to facilitate sensing the capacitance change caused by the light pinch pressure of the finger or the pressure of the finger. By setting the window hole, the electromagnetic shielding layer is fully in contact with the bottom FPC, and a good electrical connection is established, thereby ensuring the integrity of the second touch sensing electrode block in the double-layer flexible touch circuit board, and ensuring the excellent light pinch pressure sensing performance of the entire double-layer flexible touch circuit board. This embodiment does not change the structural function of the existing flexible touch circuit board. The double-layer flexible touch circuit board is a double-layer design of the top FPC and the bottom FPC, reducing the number of layers of the existing circuit from three to two. At the same time, an electromagnetic shielding layer is set to supplement the missing part of the shape of the second touch sensing electrode block caused by the wiring of the bottom FPC, so that the touch sensing sensitivity of the double-layer flexible touch circuit board is not affected, ensuring the user experience. The double-layer design reduces the thickness of the FPC, increases its softness, and improves the light pinch pressure sensing experience. At the same time, the electromagnetic shielding layer has a simple process and is easy to manufacture, which can reduce the overall manufacturing cost by more than 30%.

[0044] The embodiment is only a specific example and does not represent only one implementation mode of the present invention.

[0045] Embodiment 2:

[0046] The difference between the second embodiment and the first embodiment is that the electromagnetic shielding layer is not arranged to eliminate the influence of the incomplete part of the second touch sensing electrode block on the touch sensitivity of the double-layer flexible touch circuit board, that is, no additional electromagnetic shielding layer is arranged, so that the touch channel routing can be balanced between the intersection gaps of the sensing electrode blocks, which reduces the occupation of the sensing electrode blocks and better reduces the thickness of the FPC.

[0047] The input of the Ca amplifier is connected to the CH1 touch channel to be detected through a switch. During the detection scan cycle, the phase logic control signal of each SW switch is used to sample the input voltage and perform detection and storage after analog-to-digital conversion. Multiple phase control signals can be output on a touch channel for repeated detection, and then accumulated and summed to reduce the impact of random noise. Fig.16As shown, the program algorithm of this embodiment is to detect 6 touch channels and group dozens of touch channels into groups of 6. In one detection cycle, each group of channels is detected in different time periods. In traditional practices, when a group of touch channels is being detected, a waveform of the detection capacitance will be displayed on this group of touch channels, while other touch channels that are not detected are generally grounded. In Example 1, the electromagnetic shielding layer is connected to a touch channel and covers all touch channel traces at a very small distance. If the channel of the electromagnetic shielding layer is grounded, a large load capacitance will be formed on other touch channels. Similarly, if the touch channel traces under the electromagnetic shielding layer are grounded, a large load capacitance will also be generated on the touch channel of the electromagnetic shielding layer. When the load capacitance of the touch channel is large, the sensitivity of the double-layer flexible touch circuit board to detect capacitance changes will be greatly reduced, or even unusable. Therefore, in this embodiment, the detection waveform of the touch channel is adjusted accordingly, and the following algorithm is used to eliminate this influence, that is, steps S300 and S400 are replaced, such as Fig.13 As shown, the specific replacement is as follows. S300': In one detection cycle, the touch channels of all groups (such as Fig.17 As shown, each group of six touch channels in this embodiment simultaneously emits waveforms with the same voltage, the same timing, and the same frequency. S400': Based on the fact that there is no voltage difference between any two touch channels at any time, according to the formula charge Q = capacitance C * voltage U, there is no charge without voltage difference, thereby eliminating the coupling capacitance between different groups of touch channels. S500': Based on the capacitance formed between the second touch sensing electrode block and the grounded metal shell, the size of the light pinching pressure on the double-layer flexible touch circuit board is obtained by detecting the capacitance change. The specific structure of this embodiment is as follows Fig.14 , Fig.15 As shown, there is no need to set up an electromagnetic shielding layer for completing the second touch sensing electrode block. The touch electrode block channel routing is combined with the corresponding detection method and the difference algorithm to offset the missing second touch sensing electrode block changes. While effectively increasing the number of channels of each touch electrode block, the amount of materials and corresponding processes required for the electromagnetic shielding layer are reduced compared with the first embodiment, thereby further reducing the thickness of the double-layer flexible touch circuit board, achieving further cost reduction, improving the softness of the double-layer circuit, and further enhancing the experience of the light pinching function.

[0048] As an optional implementation, Fig.15As shown, the touch channel routing is evenly arranged between the intersection gaps of several second touch sensing electrode blocks, so that this method can reduce the space occupied by the second touch sensing electrode blocks, thereby reducing the residual area of ​​the second touch sensing electrode blocks, facilitating to improve the sensing sensitivity of the double-layer flexible touch circuit board as much as possible, and reducing the complexity of the algorithm in this embodiment. At the same time, this balanced arrangement also makes the touch channel routing more evenly arranged, avoiding local routing being too dense, thereby reducing the thickness of the bottom FPC.

[0049] Embodiment three:

[0050] A double-layer flexible touch circuit board structure, such as Figure 5 , Figure 6 As shown, the implementation method of the double-layer flexible touch circuit board for implementing the first embodiment includes a top FPC and a bottom FPC. The top FPC is provided with a first touch sensing electrode block. Preferably, a PI covering film is glued on the top FPC. The PI covering film has the advantages of good insulation, radiation resistance and corrosion resistance, which can improve the service life and use experience of the top FPC. The bottom FPC is provided with a second touch sensing electrode block. Preferably, the positions of the first touch sensing electrode block and the second touch sensing electrode block correspond to each other, and touch channel routing or copper sheet laying is performed. An electromagnetic shielding layer is provided on the bottom FPC. The electromagnetic shielding layer is used to complete the shape missing part of the second touch sensing electrode block caused by touch channel routing or copper sheet laying. Specifically, the conductive layer in the electromagnetic shielding layer is generally a metal layer, which can play the same function as the sensing electrode block, so that a complete second touch sensing electrode block can be obtained by cooperating with the existing second touch sensing electrode block. The electromagnetic shielding layer includes a first covering film, a conductive layer and a second covering film; the first covering film and the second covering film are arranged on both sides of the conductive layer for insulation. The material of the conductive layer is selected according to needs, generally metal. Compared with the FPC without an electromagnetic film layer, an extra electromagnetic shielding layer will add a covering film, which is beneficial to the bending of the FPC, and also has a reinforcement effect on the vias, and can also reduce the connection vias of the touch surface (i.e., the top FPC). This embodiment does not change the structural function of the existing flexible touch circuit board. The double-layer flexible touch circuit board is a double-layer design of the top FPC and the bottom FPC, which reduces the number of layers of the existing circuit from three to two. At the same time, the electromagnetic shielding layer is set to supplement the missing part of the shape of the second touch sensing electrode block caused by the wiring of the bottom FPC, so that the touch sensing sensitivity of the double-layer flexible touch circuit board is not affected. At the same time, the double-layer design reduces the thickness of the FPC, increases its softness, and improves the light pinch pressure sensing experience. At the same time, the process of the electromagnetic shielding layer is simple and easy to manufacture, which can reduce the overall manufacturing cost by more than 30%.

[0051] As an optional implementation, Figure 5As shown, the double-layer flexible touch circuit board structure also includes compressed foam and grounded metal sheet. The compressed foam is connected to the bottom FPC, and the grounded metal sheet is connected to the compressed foam. The top FPC, compressed foam, and grounded metal sheet form a capacitor for sensing sliding touch operations, and the bottom FPC, compressed foam, and grounded metal sheet form a capacitor for sensing light pinching operations. Touching or lightly pinching the cover plate squeezes the compressed foam, changing the distance between the touch sensing electrode block of the top FPC or the bottom FPC and the grounded metal sheet. After the touch sensing electrode block detects the change in the capacitive electric field, it is converted into a digital signal by the touch chip and sent to the MCU. The MCU detects the value change to confirm the user's intention of sliding touch or light pinching operation.

[0052] As an optional implementation, Fig. 9 , Fig.12 As shown, the electromagnetic shielding layer is in the shape of a square or an E. The above two shapes match the shape of the touch channel routing, so that the missing part of the shape of the second touch sensing electrode block caused by the touch channel routing or the laying of copper foil can be completely completed, which is convenient for the smooth routing of the touch channel, and the electromagnetic shielding layer completely covers the touch channel routing of the bottom FPC, so as to obtain a relatively complete second touch sensing electrode block, so as to achieve a better light pinch pressure sensing experience. The electromagnetic shielding layer is printed on the surface of the bottom FPC by silk screen printing. Specifically, the conductive layer of the electromagnetic shielding layer adopts the silk screen printing process. The silk screen printing method is simple to operate, mature in technology, low in cost, and easy to control the thickness. It is also convenient for the conductive layer of the electromagnetic shielding layer to form a uniform and regular second touch sensing electrode block, so as to achieve a good light pinch pressure sensing effect.

[0053] As an optional implementation, Fig.16 As shown, the first covering film is connected to the surface of the bottom FPC, and the connection method can be gluing, etc., and a window hole is set on the first covering film. There are multiple window holes, and the specific number is set according to needs. In this embodiment, there are 3 window holes, and the multiple window holes are arranged according to needs. For example, in this embodiment, the three window holes are arranged in a straight line, and the shape of the window holes can be set to be circular, square, etc.

[0054] As an optional implementation, Figure 8 , Fig.11 As shown, the window hole is spaced apart from the first sensing hole and the second sensing hole to prevent the material of the conductive layer in the electromagnetic shielding layer from entering the first sensing hole and the second sensing hole, thereby affecting the normal light pinch sensing function of the double-layer flexible touch circuit board.

[0055] As an optional implementation, the first covering film and the second covering film are both PI covering films. PI covering film (Polyimide Film) can be used for a long time in a wide temperature range of -270°C to 400°C, and has excellent comprehensive properties such as high strength, high insulation, radiation resistance, and corrosion resistance, thereby ensuring a good electromagnetic shielding protection effect on the electromagnetic film and increasing the service life of this product.

[0056] Embodiment 4:

[0057] A touch product, the touch product includes the double-layer flexible touch circuit board structure in the third embodiment, and the touch product can be a smart electronic product. In the smart electronic product of this embodiment, the double-layer flexible touch circuit board is a double-layer design of a top FPC and a bottom FPC, reducing the number of circuit layers from three to two, and at the same time, an electromagnetic shielding layer is provided to supplement the missing part of the shape of the second touch sensing electrode block caused by the wiring of the bottom FPC, so that the touch sensing sensitivity of the double-layer flexible touch circuit board is not affected. The double-layer design makes the structural design of smart electronic products more flexible, the manufacturing is simpler and more convenient, and the manufacturing cost can also be reduced.

[0058] The aforementioned storage media that can store program codes include: static hard disks, solid-state hard disks, random access memories (SRAM), electrically erasable programmable read-only memories (EEPROM), erasable programmable read-only memories (EPROM), programmable read-only memories (PROM), read-only memories (ROM), optical storage devices, magnetic storage devices, flash memories, magnetic disks or optical disks and / or combinations of the above devices, that is, they can be implemented by any type of volatile or non-volatile storage devices or combinations thereof.

[0059] The above description is only the preferred embodiment of the present invention. It is known to those skilled in the art that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application belong to the protection scope of the present invention.

Claims

1. A double-layer flexible touch circuit board structure, characterized in that: It includes a top FPC and a bottom FPC, the top FPC is provided with a first touch sensing electrode block, the bottom FPC is provided with a second touch sensing electrode block, and touch channel routing or copper sheet laying is performed; an electromagnetic shielding layer is provided on the bottom FPC, and the electromagnetic shielding layer is used to complete the shape missing part of the second touch sensing electrode block caused by touch channel routing or copper sheet laying, so as to obtain a complete second touch sensing electrode block; the electromagnetic shielding layer includes a first covering film, a conductive layer and a second covering film; the first covering film and the second covering film are arranged on both sides of the conductive layer, and are both used for insulation; it also includes compressed foam and a grounding metal sheet, the compressed foam is connected to the bottom FPC, and the grounding metal sheet is connected to the compressed foam; the top FPC, the compressed foam, and the grounding metal sheet form a capacitor for sensing sliding touch operation, and the bottom FPC, the compressed foam, and the grounding metal sheet form a capacitor for sensing light pinching operation; the first covering film is connected to the surface of the bottom FPC, and a window hole is arranged on the first covering film; the first covering film and the second covering film are both PI covering films; The method for implementing a double-layer flexible touch circuit board includes the following steps: S100: Arrange a plurality of first touch sensing electrode blocks on a first FPC substrate, and set a first sensing hole to form a top layer FPC; S200: Arrange a plurality of second touch sensing electrode blocks corresponding to the first touch sensing electrode blocks on a second FPC substrate, set a second sensing hole, electrically connect the first sensing hole and the second sensing hole, and perform touch channel routing or copper sheet laying to form a bottom layer FPC corresponding to the shape of the top layer FPC; S300: Arrange an electromagnetic shielding layer on the bottom layer FPC, the electromagnetic shielding layer is used to complete the shape missing part of the second touch sensing electrode block caused by touch channel routing or copper sheet laying, so as to form a complete second touch sensing electrode block; the electromagnetic shielding layer is in a U-shape or an E-shape, and the electromagnetic shielding layer is printed on the surface of the bottom layer FPC by silk screen printing; S4 00: A window hole is set in the electromagnetic shielding layer, and the electromagnetic shielding layer is electrically connected to the touch channel wiring or the laid copper sheet through the window hole to realize pressure sensing and light pinch pressure sensing of the bottom FPC; the window hole is spaced apart from the first sensing hole and the second sensing hole; the number of the window holes is multiple, and the window holes are round holes or square holes.

2. A touch product, characterized in that: The touch product comprises the double-layer flexible touch circuit board structure according to claim 1.

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