Display screen cover plate structure and preparation method thereof

Abstract

According to the display screen cover plate structure and the preparation method thereof provided by the invention, the first hardening and buffering integrated layer and the second hardening and buffering integrated layer are formed by adopting an integrated forming process, so that the problem of stress concentration caused by a multi-layer stacked hardening layer and buffering layer structure in the prior art is effectively solved; according to the integrated design, the folding service life is prolonged, the reliability is improved, the production cost is reduced, the process complexity is reduced, in addition, the touch conducting layer is integrated on the UFG base material layer, the integrated design of the touch electrode and the cover plate is achieved, the overall thickness and weight of a display screen product are remarkably reduced, and the production cost is reduced. And the thickness of the UFG base material layer in the non-folding area is greater than that of the UFG base material layer in the folding area, so that the structure of the cover plate is further optimized, the overall flexibility of a display screen product is improved, and the folding performance of a multi-folding display screen product with more than two folds is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of display device preparation, and particularly to a display screen cover plate structure and a preparation method thereof. Background Art

[0002] With the rapid development of electronic products (such as folding mobile phones, tablet computers, etc.), the requirements for display screen cover plates are getting higher and higher. In the traditional display screen cover plate structure, the hardening layer and the buffer layer formed on the ultra-thin glass (UTG, Ultra Thin Glass) usually adopt a multi-layer stacking structure. For example, a three-layer stacking process of OCA (optical adhesive) + CPI (polyimide) or TPU (thermoplastic polyurethane) + HC (hardening coating) is used. Although this structure can meet certain requirements, there are many problems in folding screen products: stress concentration is likely to occur during the folding process, resulting in material damage, affecting the folding life and reliability; the multi-layer stacking process requires multiple coating, curing, and bonding steps, increasing the production cost and process complexity; it is difficult to balance the flexibility and wear resistance of traditional materials (such as CPI and TPU), and it is difficult to meet the requirements for high-performance materials in folding screen products.

[0003] In addition, traditional display screen products generally have an externally mounted touch electrode plate, and the thickness of the traditional display screen cover plate is relatively large (usually not less than 400 microns), and the thickness of the externally mounted touch electrode plate is usually not less than 95 microns. Therefore, the total thickness of the traditional display screen cover plate and the externally mounted touch electrode plate is not less than 495 microns, resulting in a relatively large overall thickness and weight of the product, restricting the thin and light design of the display screen product. Especially in the context of the rapid development of folding screen products, the limitations of the traditional display screen cover plate structure and preparation method are gradually emerging. Summary of the Invention

[0004] In view of the above-mentioned disadvantages of the prior art, the purpose of the present invention is to provide a display screen cover plate structure and a preparation method thereof, which are used to solve the problems of insufficient flexibility and complex process caused by the multi-layer stacked hardening layer and buffer layer structure in the existing display screen cover plate structure, and the problems of large thickness and heavy weight caused by the externally mounted touch electrode plate of the display screen device.

[0005] To achieve the above purpose and other related purposes, the present invention provides a display screen cover plate structure, which sequentially includes, from the screen end to the client end: a first hardening and buffering integrated layer, a UFG substrate layer, a second hardening and buffering integrated layer, and an optical functional layer; wherein, the UFG substrate layer includes at least three non-folding regions spaced along the length direction and at least two folding regions sandwiched between the non-folding regions; The UFG substrate layer has a first surface close to the screen end and a second surface close to the client side. A first folding groove is formed on the first surface of the UFG substrate layer in the folding area, and a second folding groove is formed on the second surface of the UFG substrate layer in the folding area. The first folding groove and the second folding groove are respectively located in different folding areas, and the first folding groove and the second folding groove are arranged alternately along the length direction of the UFG substrate layer, so that the thickness of the UFG substrate layer in the non-folding area is greater than the thickness of the UFG substrate layer in the folding area; A touch conductive layer is formed on the first surface of the UFG substrate layer except for the first folding groove and / or on the second surface of the UFG substrate layer except for the second folding groove.

[0006] Optionally, the thickness of the UFG substrate layer in the folding area is 30 µm to 70 µm, the thickness of the UFG substrate layer in the non-folding area is 70 µm to 230 µm, and the thickness of the UFG substrate layer corresponding to the second folding groove is greater than the thickness of the UFG substrate layer corresponding to the first folding groove.

[0007] Optionally, the touch conductive layer includes a first touch conductive layer formed on the first surface of the UFG substrate layer except for the first folding groove and a second touch conductive layer formed on the second surface of the UFG substrate layer except for the second folding groove, and a first wiring layer is formed at the outer edge of the surface of the first touch conductive layer close to the screen end, and a second wiring layer is formed at the outer edge of the surface of the second touch conductive layer close to the client side.

[0008] Furthermore, the first touch conductive layer further includes a first mesh-shaped conductive layer formed on the bottom wall and side wall of the first folding groove, and the second touch conductive layer further includes a second mesh-shaped conductive layer formed on the bottom wall and side wall of the second folding groove.

[0009] Optionally, the touch conductive layer is formed on the second surface of the UFG substrate layer except for the second folding groove, and a third wiring layer is formed at the outer edge of the surface of the touch conductive layer close to the client side.

[0010] Optionally, the material of the first hardening and buffering integrated layer includes at least one of acrylic acid and polyurethane, and at least one of silicon oxide and aluminum oxide; the material of the second hardening and buffering integrated layer includes at least one of acrylic acid and polyurethane, and at least one of silicon oxide and aluminum oxide.

[0011] Optionally, the first folding groove is a trapezoidal groove that is smaller at the screen end and larger at the client end, the second folding groove is a trapezoidal groove that is larger at the screen end and smaller at the client end, and the falling angles of the first folding groove and the second folding groove are both arc-shaped.

[0012] The present invention also provides a method for preparing a display screen cover plate structure, and the preparation method includes: S1, providing a UFG substrate layer, the UFG substrate layer having a first surface close to the screen end and a second surface close to the client end, and the UFG substrate layer including at least three spaced non-folding regions and at least two folding regions sandwiched between the non-folding regions; S2, forming a first folding groove on the first surface of the UFG substrate layer in the folding region, and forming a second folding groove on the second surface of the UFG substrate layer in the folding region, the first folding groove and the second folding groove being formed in different folding regions respectively, and the first folding groove and the second folding groove being alternately arranged along the length direction of the UFG substrate layer, so that the thickness of the UFG substrate layer in the non-folding region is greater than the thickness of the UFG substrate layer in the folding region; S3, forming a touch conductive layer on the first surface of the UFG substrate layer except for the first folding groove and / or on the second surface of the UFG substrate layer except for the second folding groove; S4, using an integrated molding process to form a first hardened buffer integrated layer on the surface of the obtained structure close to the screen end, covering the first surface of the UFG substrate layer and filling the first folding groove, and using an integrated molding process to form a second hardened buffer integrated layer on the surface of the obtained structure close to the client end, covering the second surface of the UFG substrate layer and filling the second folding groove; S5, forming an optical functional layer on the surface of the second hardened buffer integrated layer close to the client end.

[0013] Optionally, after step S2, it further includes a step of performing laser micro-nano polishing or local etching treatment on the first folding groove and the second folding groove, so that the first folding groove is a trapezoidal groove that is smaller at the screen end and larger at the client end, the second folding groove is a trapezoidal groove that is larger at the screen end and smaller at the client end, and the falling angles of the first folding groove and the second folding groove are both arc-shaped.

[0014] Optionally, after step S2, it further includes a step of thinning the UFG substrate layer corresponding to the first folding groove, so that the thickness of the UFG substrate layer corresponding to the second folding groove is greater than the thickness of the UFG substrate layer corresponding to the first folding groove.

[0015] Optionally, in step S3, an evaporation coating process or a magnetron sputtering process is adopted, and the touch conductive layer is formed by combining a photolithography etching process, and the annealing temperatures of both the evaporation coating process and the magnetron sputtering process are lower than 100°C.

[0016] Optionally, in step S3, the method for forming the touch conductive layer includes: S31, forming a first touch conductive layer on the first surface of the UFG substrate layer except for the first folding groove, and forming a second touch conductive layer on the second surface of the UFG substrate layer except for the second folding groove; S32, forming a first wiring layer at the outer edge of the surface of the first touch conductive layer close to the screen end, and forming a second wiring layer at the outer edge of the surface of the second touch conductive layer close to the client side.

[0017] Further, it is characterized in that: in step S31, it further includes the steps of forming a first grid-shaped conductive layer on the bottom wall and side wall of the first folding groove, and forming a second grid-shaped conductive layer on the bottom wall and side wall of the second folding groove, wherein the first grid-shaped conductive layer is in contact connection with the first touch conductive layer, and the second grid-shaped conductive layer is in contact connection with the second touch conductive layer.

[0018] Optionally, in step S3, the method for forming the touch conductive layer includes: S31, forming a third touch conductive layer on the second surface of the UFG substrate layer except for the second folding groove; S32, forming a third wiring layer at the outer edge of the surface of the third touch conductive layer close to the client side.

[0019] Optionally, in step S4, a 3D printing process is adopted in combination with a curing treatment to form the first hardening buffer integrated layer and the second hardening buffer integrated layer. The solid content of the material used for the 3D printing process is 100%, and the method of the curing treatment is separate UV curing.

[0020] As described above, the display screen cover plate structure and its manufacturing method of the present invention have the following beneficial effects: By adopting an integrated molding process to form the first hardening and buffering integrated layer and the second hardening and buffering integrated layer, the problem of stress concentration caused by the structure of the hardening layer and the buffering layer stacked in multiple layers in the prior art is effectively solved. This integrated design not only improves the folding life and reliability, but also reduces the production cost and process complexity. In addition, by integrating the touch conductive layer on the UFG substrate layer, the integrated design of the touch electrode and the cover plate is realized, significantly reducing the overall thickness and weight of the display screen product. And by making the thickness of the UFG substrate layer in the non-folding area greater than that of the UFG substrate layer in the folding area, the structure of the cover plate is further optimized, improving the overall flexibility of the display screen product, and at the same time improving the folding performance of the multi-fold display screen product with more than double folds. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 FIG. shows a schematic cross-sectional structure of a display screen cover plate structure according to an example of the present invention.

[0022] Figure 2 FIG. shows a schematic cross-sectional structure of a display screen cover plate structure according to another example of the present invention.

[0023] Figure 3 FIG. shows a schematic cross-sectional structure of a folding groove in the display screen cover plate structure of the present invention.

[0024] Figure 4 FIG. shows a schematic flow chart of the manufacturing method of the display screen cover plate structure of the present invention.

[0025] Description of Component Labels: 10 First hardening and buffering integrated layer, 11 UFG substrate layer, 12 Second hardening and buffering integrated layer, 13 Optical functional layer, 14 First touch conductive layer, 15 Second touch conductive layer, 16 First wiring layer, 17 Second wiring layer, 18 Third touch conductive layer, 19 Third wiring layer, 21 First folding groove, 22 Second folding groove, 31 First grid-shaped conductive layer, 32 Second grid-shaped conductive layer, 33 Third grid-shaped conductive layer, 40 Drop corner, S1~S5 Steps. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] The following specifically illustrates the embodiments of the present invention through specific examples. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0027] Please refer to Figures 1 to 4It should be noted that the illustrations provided in this embodiment only schematically illustrate the basic concept of the present invention. Therefore, only the components related to the present invention are shown in the illustrations, rather than being drawn according to the number, shape, and size of the components in actual implementation. The type, quantity, and ratio of each component in actual implementation can be arbitrarily changed, and the component layout type may also be more complex.

[0028] This embodiment provides a display screen cover plate structure, as Figure 1 and Figure 2 shown, the cover plate structure successively includes from the screen end to the client end: a first hardening and buffering integrated layer 10, a UFG substrate layer 11, a second hardening and buffering integrated layer 12, and an optical function layer 13; wherein, the UFG substrate layer 11 includes at least three non-fold regions arranged at intervals along the length direction and at least two fold regions sandwiched between the non-fold regions; the UFG substrate layer 11 has a first surface close to the screen end and a second surface close to the client end. A first folding groove 21 is formed on the first surface of the UFG substrate layer 11 in the fold region, and a second folding groove 22 is formed on the second surface of the UFG substrate layer 11 in the fold region. The first folding groove 21 and the second folding groove 22 are respectively located in different fold regions, and the first folding groove 21 and the second folding groove 22 are alternately arranged along the length direction of the UFG substrate layer 11, so that the thickness of the UFG substrate layer 11 in the non-fold region is greater than the thickness of the UFG substrate layer 11 in the fold region; A touch conductive layer is formed on the first surface of the UFG substrate layer 11 except for the first folding groove 21 and / or on the second surface of the UFG substrate layer 11 except for the second folding groove 22.

[0029] The display screen cover plate structure of this embodiment effectively solves the stress concentration problem caused by the multi-layer stacked hardening layer and buffer layer structure in the prior art by adopting the first hardening and buffering integrated layer and the second hardening and buffering integrated layer. This integrated design not only improves the folding life and reliability, but also reduces the production cost and process complexity. In addition, by integrating the touch conductive layer on the UFG substrate layer, the integrated design of the touch electrode and the cover plate is realized, significantly reducing the overall thickness and weight of the display screen product. And by making the thickness of the UFG substrate layer in the non-fold region greater than the thickness of the UFG substrate layer in the fold region, the structure of the cover plate is further optimized, improving the overall flexibility of the display screen product, and at the same time improving the folding performance of the multi-fold display screen product with more than two folds.

[0030] As an example, the number of the non-fold regions and the fold regions can be designed and adjusted according to the actual number of folding surfaces of the display screen, such asFigure 1 and Figure 2 As shown in Figure 2 , this embodiment takes the example that the UFG substrate layer includes three non - folding regions and two folding regions for illustration.

[0031] As an example, as Figure 1 and Figure 2 shown, the thickness of the UFG substrate layer 11 in the folding region is 30 µm to 70 µm, and the thickness of the UFG substrate layer 11 in the non - folding region is 70 µm to 230 µm. Among them, the thinner folding region has higher flexibility and can achieve a smaller folding radius (folding R - angle), thereby improving the folding performance of the folding - screen device. The thicker non - folding region can provide sufficient structural strength and wear resistance to protect the display product from external damage. The thickness of the UTG substrate layer 11 in the folding region can be selected according to the size of the folding R - angle of the actual product. Specifically, when the folding R - angle is small (for example, 1.0 mm), the thickness of the UTG substrate layer 11 in the folding region can be selected as 30 µm, for example, to achieve higher flexibility; when the folding R - angle is large (for example, 4.5 mm), the thickness of the UTG substrate layer 11 in the folding region can be selected as 70 µm, for example, to ensure sufficient structural strength, so that the display cover plate can maintain good performance at different folding R - angles, effectively reducing stress concentration during the folding process and improving the folding life and reliability.

[0032] Furthermore, as Figure 1 and Figure 2 shown, when folding, the folding - screen product folds away from the client direction at the first folding groove 21, and the inner side of the curl wraps the folding backplane and the folding display screen. If the thickness of this region is too thick, it will cause the folding R - angle to be unable to be made small, thus affecting the folding performance and the thin - and - light design of the device. In order to optimize the performance of the folding - screen cover plate structure, in this embodiment, it is preferably set that the thickness of the UFG substrate layer 11 corresponding to the second folding groove 22 is greater than the thickness of the UFG substrate layer 11 corresponding to the first folding groove 21. The thickness corresponding to the first folding groove 21 is 30 µm, for example. By designing the UFG substrate layer 11 at the first folding groove 21 to be thinnest, the folding R - angle can be significantly reduced, and the folding life and reliability can be improved.

[0033] As an example, as Figure 1 and Figure 2As shown, the thickness of the first hardening buffer layer 10 is 4 µm to 10 µm, and the thickness of the second hardening buffer layer 12 is 15 µm to 25 µm. Among them, the relatively thin first hardening buffer integrated layer 10 helps to improve the overall flexibility of the display cover plate, enabling it to better adapt to the folding action. The relatively thick second hardening buffer integrated layer 12 helps to resist scratches and wear from the client side and extends the service life of the product. The specific thicknesses of the first hardening buffer integrated layer 10 and the second hardening buffer integrated layer 12 can be adjusted according to the actual folding R corner design requirements and are not overly restricted here.

[0034] The formation position of the touch conductive layer on the UTG substrate layer 11 can be adjusted according to the actual touch mode requirements. As an example, to achieve the mutual capacitance touch mode requirements, such as Figure 1 As shown, the touch conductive layer includes a first touch conductive layer 14 formed on the first surface of the UFG substrate layer 11 except for the first folding groove 21 and a second touch conductive layer 15 formed on the second surface of the UFG substrate layer 11 except for the second folding groove 22. And a first wiring layer 16 is formed at the outer edge of the surface of the first touch conductive layer 14 close to the screen end, and a second wiring layer 17 is formed at the outer edge of the surface of the second touch conductive layer 15 close to the client side. It should be noted here that the outer edge refers to the edge of the target structure corresponding to the outer periphery side of the UFG substrate layer 11.

[0035] Among them, the first touch conductive layer 14 is formed on the first surface of the UFG substrate layer 11 except for the first folding groove 21, and the second touch conductive layer 15 is formed on the second surface of the UFG substrate layer 11 except for the second folding groove 22. In addition, the bottom wall and side wall of the first folding groove 21 may or may not be formed with the first touch conductive layer 14, and the bottom wall and side wall of the second folding groove 22 may or may not be formed with the second touch conductive layer 15. In this embodiment, it is preferably set that the first touch conductive layer 14 further includes a first mesh-shaped conductive layer 31 formed on the bottom wall and side wall of the first folding groove 21, and the second touch conductive layer 15 further includes a second mesh-shaped conductive layer 32 formed on the bottom wall and side wall of the second folding groove 22. The first mesh-shaped conductive layer 31 and the second mesh-shaped conductive layer 32 can increase the flexibility of the touch conductive layer while ensuring the signal transmission performance, enabling it to better adapt to the folding action. It should be noted here that the widths and spacings of the first mesh-shaped conductive layer 31 and the second mesh-shaped conductive layer 32 can be adjusted according to the process conditions and folding requirements, which are not specifically shown here and are not overly limited.

[0036] The first wiring layer 16 is used to implement the control and feedback of the integrated circuit to the first touch conductive layer 14. As a further example, the material of the first wiring layer 16 includes one of silver paste, copper, copper alloy, and a stack of molybdenum / lithium / molybdenum. Using its smaller resistivity, a smaller circuit load can be achieved, reducing delay and loss. The second wiring layer 17 is preferably made of a black conductive material, which can not only be used to implement the control and feedback of the integrated circuit to the second touch conductive layer 15, but also reduce the light leakage around the display product, especially on both sides of the display, improving the optical performance of the display product.

[0037] As a further example, the thickness of the first wiring layer 16 is less than 5 µm, the thickness of the second wiring layer 17 is less than 5 µm, the thickness of the first touch conductive layer 14 is less than 100 nm, and the thickness of the second touch conductive layer 14 is less than 100 nm, enabling it to ensure normal electrical functions while achieving a smaller integrated thickness and better flexibility.

[0038] As another example, to meet the requirements of the self-capacitive touch mode, the touch conductive layer can be formed on the first surface of the UFG substrate layer 11 except for the first folding groove 21 or on the second surface of the UFG substrate layer 11 except for the second folding groove 22. When folding, the folding screen product folds away from the client at the first folding groove 21. The inner side of the curl wraps the folding backplane and the folding display screen. If the thickness of this area is too thick, it will cause the folding R corner to be unable to be made small, thus affecting the folding performance and the thin and light design of the device. The folding screen product folds towards the client at the second folding groove 22, and the thickness of the inner side of the curl is smaller. Therefore, to optimize the performance of the folding screen cover plate, as Figure 2 shown, in this embodiment, it is preferably set that the touch conductive layer is formed on the second surface of the UFG substrate layer 11 except for the second folding groove 22 to reduce the thickness of the inner side of the curl of the UFG substrate layer 11 corresponding to the first folding groove 21 when folding. Specifically, the formed touch conductive layer is the third touch conductive layer 18. Preferably, the third touch conductive layer 18 further includes a third mesh-shaped conductive layer 33 formed on the bottom wall and side walls of the second folding groove 22. The third mesh-shaped conductive layer 33 can increase the flexibility of the third touch conductive layer 18 while ensuring the signal transmission performance, enabling it to better adapt to the folding movement. It should be noted here that the width and spacing of the third mesh-shaped conductive layer 33 can be adjusted according to process conditions and folding requirements, which are not specifically shown here and are not overly limited.

[0039] As an example, a third wiring layer 19 is formed on the peripheral edge of the surface of the third touch conductive layer 18 close to the screen end. The third wiring layer 19 preferably uses a black conductive material, so that it can not only be used to realize the control and feedback of the integrated circuit to the third touch conductive layer 18, but also reduce the light leakage around the display screen, especially on both sides of the display screen, and improve the optical performance of the display screen product.

[0040] As a further example, the thickness of the third wiring layer 19 is less than 5 µm, and the thickness of the touch conductive layer 18 is less than 100 nm, so that while achieving a smaller integrated thickness and better flexibility, its normal electrical functions can be ensured.

[0041] As an example, the material of the first hardening and buffering integrated layer 10 includes at least one of acrylic acid and polyurethane, and at least one of silicon oxide and aluminum oxide. The material of the second hardening and buffering integrated layer 12 includes at least one of acrylic acid and polyurethane, and at least one of silicon oxide and aluminum oxide. By combining organic materials (acrylic acid and polyurethane) with inorganic materials (silicon oxide and aluminum oxide), the balance between hardness and flexibility is achieved, thereby improving the folding life and reliability. Of course, the materials of the first hardening and buffering integrated layer 10 and the second hardening and buffering integrated layer 12 can also be other organic materials and inorganic materials, which can be specifically selected according to actual needs and are not overly restricted here.

[0042] As an example, the display screen cover structure further includes a flexible printed circuit board (FPC, Flexible Printed Circuit), and the FPC is in contact connection with the touch conductive layer to realize the touch feedback of the display screen product.

[0043] As an example, as Figure 3 shown, the first folding groove 21 is a trapezoidal groove with a smaller upper part and a larger lower part in the direction from the screen end to the client end, and the second folding groove 22 is a trapezoidal groove with a larger upper part and a smaller lower part in the direction from the screen end to the client end. Moreover, the falling angles 40 of the first folding groove 21 and the second folding groove 22 are both arc-shaped, so as to reduce the stress concentration caused by acute angle lines, improve the folding performance, and at the same time avoid the resulting optical interference, enhance the visual consistency, optimize the light propagation, thereby improving the overall optical performance.

[0044] This embodiment also provides a preparation method for the display screen cover structure for preparing the above-mentioned display screen cover structure, but it is not limited thereto, and other suitable preparation methods can also be used. The foregoing content can be fully cited here. For the sake of brevity, it will not be repeated hereinafter. As Figure 4 shown, the preparation method includes: S1. Provide a UFG substrate layer. The UFG substrate layer has a first surface close to the screen end and a second surface close to the client side. And the UFG substrate layer includes at least three non - folding regions arranged at intervals and at least two folding regions sandwiched between the non - folding regions; S2. Form a first folding groove on the first surface of the UFG substrate layer in the folding region, and form a second folding groove on the second surface of the UFG substrate layer in the folding region. The first folding groove and the second folding groove are respectively formed in different folding regions, and the first folding groove and the second folding groove are alternately arranged along the length direction of the UFG substrate layer, so that the thickness of the UFG substrate layer in the non - folding region is greater than the thickness of the UFG substrate layer in the folding region; S3. Form a touch conductive layer on the first surface of the UFG substrate layer except for the first folding groove and / or on the second surface of the UFG substrate layer except for the second folding groove; S4. Use an integrated molding process to form a first hardened buffer integrated layer on the surface of the obtained structure close to the screen end, covering the first surface of the UFG substrate layer and filling the first folding groove. Use an integrated molding process to form a second hardened buffer integrated layer on the surface of the obtained structure close to the client side, covering the second surface of the UFG substrate layer and filling the second folding groove; S5. Form an optical functional layer on the surface of the second hardened buffer integrated layer close to the client side.

[0045] In the preparation method of the display screen cover structure of this embodiment, by using an integrated molding process to form the first hardened buffer integrated layer and the second hardened buffer integrated layer, the problem of stress concentration caused by the multi - layer stacked hardened layer and buffer layer structure in the prior art is effectively solved. This integrated design not only improves the folding life and reliability, but also reduces the production cost and process complexity. In addition, by integrating the touch conductive layer on the UFG substrate layer, the integrated design of the touch electrode and the cover plate is realized, significantly reducing the overall thickness and weight of the display screen product. And by making the thickness of the UFG substrate layer in the non - folding region greater than the thickness of the UFG substrate layer in the folding region, the structure of the cover plate is further optimized, improving the overall flexibility of the display screen product and at the same time enhancing the folding performance of the multi - folding display screen product with more than two folds.

[0046] The following combines Figures 1 to 3 to elaborate in detail on the preparation method of the display screen cover structure of this embodiment.

[0047] As an example, in step S1, the method for forming the UFG substrate layer 11 generally includes steps of thinning, edge grinding, and strengthening treatment of the UFG raw material; wherein, the thickness of the UFG raw material is generally relatively large, for example, greater than 230 µm.

[0048] As an example, in step S2, a photolithography etching process can be used to form the first folding groove 21 and the second folding groove 22. As Figure 3 shown, in this embodiment, after step S2, there is also a step of performing laser micro-nano polishing or local etching treatment on the first folding groove 21 and the second folding groove 22, so that the first folding groove 21 is a trapezoidal groove with a smaller upper part and a larger lower part in the direction from the screen end to the client end, the second folding groove 22 is a trapezoidal groove with a larger upper part and a smaller lower part in the direction from the screen end to the client end, and the falling angles 40 of the first folding groove 21 and the second folding groove 22 are both arc-shaped, so as to reduce stress concentration caused by acute-angle patterns, improve the folding performance, and at the same time avoid optical interference caused thereby, enhance visual consistency, optimize light propagation, and thus improve the overall optical performance.

[0049] As an example, after step S2, there is also a step of thinning the UFG substrate layer 11 corresponding to the first folding groove 21, so that the thickness of the UFG substrate layer 11 corresponding to the second folding groove 22 is greater than the thickness of the UFG substrate layer 11 corresponding to the first folding groove 21, so as to reduce the folding R angle and improve the folding life and reliability.

[0050] As an example, in step S3, a vapor deposition process or a magnetron sputtering process can be used, in combination with a photolithography etching process, to form the touch conductive layer. The vapor deposition process and the magnetron sputtering process in this embodiment preferably adopt a low-temperature film-forming process, and the annealing temperatures of the vapor deposition process and the magnetron sputtering process are both lower than 100 °C. The vapor deposition process at a lower temperature can significantly reduce the yellowing of the touch conductive layer material, maintain the high transparency and color accuracy of the display screen product, and at the same time reduce the stress concentration of the UTG substrate layer, thereby reducing the risk of its cracking. For example, in other embodiments, when high-temperature annealing (280 °C) is used, the cracking rate of the UTG substrate layer increases by at least 40% compared with the lower annealing temperature in this embodiment.

[0051] As an example, in step S4, a 3D printing process is combined with a curing treatment to form the first hardening buffer integrated layer and the second hardening buffer integrated layer. Among them, the method of the curing treatment includes one of separate UV curing, separate thermal curing, and dual curing of UV curing and thermal curing, so that the first hardening buffer integrated layer and the second hardening buffer integrated layer take into account high hardness and high flexibility. The specific curing method can be selected according to specific materials and scenario requirements, and no excessive restrictions are made here.

[0052] As a further example, the solid content of the material for the 3D printing process is preferably 100%, and the method of the curing treatment is preferably separate UV curing, so that the material can be quickly cross-linked and cured without the need for additional heat sources, reducing or even avoiding safety accidents caused by solvent volatilization.

[0053] Generally speaking, the optical functional layer specifically includes an anti-glare, anti-reflection, and anti-fingerprint layer. As an example, in step S5, a 3D printing process can be used to form the optical functional layer. The overall thickness of the formed optical functional layer is generally less than 5 µm, for example, about 1 µm, making it have better flexibility, increasing the design space of the folding R angle, and improving production efficiency at the same time.

[0054] The formation position of the touch conductive layer on the UTG substrate layer can be adjusted according to the actual touch mode requirements. As an example, as Figure 1 shown, in order to meet the requirements of the mutual capacitance touch mode, in step S3, the method of forming the touch conductive layer includes: S31, forming a first touch conductive layer 14 on the first surface of the UFG substrate layer 11 except for the first folding groove 21, and forming a second touch conductive layer 15 on the second surface of the UFG substrate layer 11 except for the second folding groove 22; in addition, the bottom wall and side walls of the first folding groove 21 can be selectively formed with the first touch conductive layer 14 or not formed with the first touch conductive layer 14, and the bottom wall and side walls of the second folding groove 22 can be selectively formed with the second touch conductive layer 15 or not formed with the second touch conductive layer 15. Preferably, this step further includes the steps of forming a first grid-shaped conductive layer 31 on the bottom wall and side walls of the first folding groove 21, and forming a second grid-shaped conductive layer 32 on the bottom wall and side walls of the second folding groove 22. Among them, the first grid-shaped conductive layer 31 is in contact connection with the first touch conductive layer 21, and the second grid-shaped conductive layer 32 is in contact connection with the second touch conductive layer 22. The first grid-shaped conductive layer 31 and the second grid-shaped conductive layer 32 can increase the flexibility of the touch conductive layer while ensuring the signal transmission performance, enabling it to better adapt to the folding action.

[0055] S32. A first wiring layer 16 is formed at the outer edge of the surface of the first touch conductive layer 14 close to the screen end, and a second wiring layer 17 is formed at the outer edge of the surface of the second touch conductive layer 15 close to the client end. Among them, the first wiring layer 16 can be formed by screen printing process or magnetron sputtering process combined with photolithography etching process. Preferably, in this embodiment, the first wiring layer 16 is formed by magnetron sputtering process combined with photolithography etching process. The material of the first wiring layer 16 is copper, and the thickness of the formed first wiring layer is less than 1000 angstroms, so that the UFG substrate layer 11 has better flexibility and reduces the risk of its cracking.

[0056] As another example, in order to meet the self-capacitive touch mode requirement, the touch conductive layer can be formed on the first surface of the UFG substrate layer 11 except for the first folding groove 21 or on the second surface of the UFG substrate layer 11 except for the second folding groove 22. When folding, the folding screen product folds away from the client end at the first folding groove 21, and the inner side of the curl wraps the folding backplane and the folding display screen. If the thickness of this area is too thick, it will cause the folding R corner to be unable to be made small. Preferably, as Figure 2 shown, the method for forming the touch conductive layer in this embodiment includes: S31. A third touch conductive layer is formed on the second surface of the UFG substrate layer except for the second folding groove. S32. A third wiring layer 19 is formed at the outer edge of the surface of the third touch conductive layer 18 close to the client end. Preferably, the third touch conductive layer 18 further includes a third mesh-shaped conductive layer 33 formed on the bottom wall and side walls of the second folding groove 22, and the third mesh-shaped conductive layer 33 is in contact connection with the third touch conductive layer 18. While ensuring the signal transmission performance, the third mesh-shaped conductive layer 33 can also increase the flexibility of the third touch conductive layer 18, enabling it to better adapt to the folding action. It should be noted here that the width and spacing of the third mesh-shaped conductive layer 33 can be adjusted according to process conditions and folding requirements, which are not specifically shown here and are not overly limited.

[0057] In summary, for the display cover plate structure and its preparation method of the present invention, by adopting an integrated molding process to form the first hardened buffer integrated layer and the second hardened buffer integrated layer, the problem of stress concentration caused by the structure of the hardened layer and the buffer layer stacked in multiple layers in the prior art is effectively solved. This integrated design not only improves the folding life and reliability, but also reduces the production cost and process complexity. In addition, by integrating the touch conductive layer on the UFG substrate layer, the integrated design of the touch electrode and the cover plate is realized, significantly reducing the overall thickness and weight of the display product. By making the thickness of the UFG substrate layer in the non-folding area greater than that of the UFG substrate layer in the folding area, the structure of the cover plate is further optimized, improving the overall flexibility of the display product and at the same time improving the folding performance of the multi-fold display product with more than double folds. Therefore, the present invention effectively overcomes various shortcomings in the prior art and has high industrial utilization value.

[0058] The above embodiments are only illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes completed by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A display screen cover plate structure, characterized in that, The cover plate structure successively includes, from the screen end to the client end: a first hardening and buffering integrated layer, a UFG substrate layer, a second hardening and buffering integrated layer, and an optical functional layer; wherein, the UFG substrate layer includes at least three non-fold regions spaced along the length direction and at least two fold regions sandwiched between the non-fold regions; the UFG substrate layer has a first surface close to the screen end and a second surface close to the client end. A first folding groove is formed on the first surface of the UFG substrate layer in the fold region, and a second folding groove is formed on the second surface of the UFG substrate layer in the fold region. The first folding groove and the second folding groove are respectively located in different fold regions, and the first folding groove and the second folding groove are alternately arranged along the length direction of the UFG substrate layer, so that the thickness of the UFG substrate layer in the non-fold region is greater than the thickness of the UFG substrate layer in the fold region; a touch conductive layer is formed on the first surface of the UFG substrate layer except for the first folding groove and / or on the second surface of the UFG substrate layer except for the second folding groove.

2. The display screen cover plate structure according to claim 1, wherein: The thickness of the UFG substrate layer in the fold region is 30 µm to 70 µm, the thickness of the UFG substrate layer in the non-fold region is 70 µm to 230 µm, and the thickness of the UFG substrate layer corresponding to the second folding groove is greater than the thickness of the UFG substrate layer corresponding to the first folding groove.

3. The display screen cover plate structure according to claim 1, wherein: The touch conductive layer includes a first touch conductive layer formed on the first surface of the UFG substrate layer except for the first folding groove and a second touch conductive layer formed on the second surface of the UFG substrate layer except for the second folding groove. A first wiring layer is formed at the outer edge of the surface of the first touch conductive layer close to the screen end, and a second wiring layer is formed at the outer edge of the surface of the second touch conductive layer close to the client end.

4. The display screen cover plate structure according to claim 3, wherein: The first touch conductive layer further includes a first mesh-shaped conductive layer formed on the bottom wall and side walls of the first folding groove, and the second touch conductive layer further includes a second mesh-shaped conductive layer formed on the bottom wall and side walls of the second folding groove.

5. The display screen cover plate structure according to claim 1, wherein: The touch conductive layer is formed on the second surface of the UFG substrate layer except for the second folding groove, and a third wiring layer is formed at the outer edge of the surface of the touch conductive layer close to the client end.

6. The display screen cover plate structure according to claim 1, characterized in that: The material of the first hardening and buffering integrated layer includes at least one of acrylic and polyurethane, and at least one of silicon oxide and aluminum oxide; the material of the second hardening and buffering integrated layer includes at least one of acrylic and polyurethane, and at least one of silicon oxide and aluminum oxide.

7. The display screen cover plate structure according to claim 1, wherein: The first folding groove is a trapezoidal groove with a smaller upper part and a larger lower part along the direction from the screen end to the client end, the second folding groove is a trapezoidal groove with a larger upper part and a smaller lower part along the direction from the screen end to the client end, and the falling angles of the first folding groove and the second folding groove are both arc-shaped.

8. A preparation method of a display screen cover plate structure, characterized in that, The preparation method includes: S1. Provide a UFG substrate layer, which has a first surface close to the screen end and a second surface close to the client side, and the UFG substrate layer includes at least three non-folded areas arranged at intervals and at least two folded areas sandwiched between the non-folded areas; S2. Form a first folding groove on the first surface of the UFG substrate layer in the folded area, and form a second folding groove on the second surface of the UFG substrate layer in the folded area. The first folding groove and the second folding groove are respectively formed in different folded areas, and the first folding groove and the second folding groove are alternately arranged along the length direction of the UFG substrate layer, so that the thickness of the UFG substrate layer in the non-folded area is greater than the thickness of the UFG substrate layer in the folded area; S3. Form a touch conductive layer on the first surface of the UFG substrate layer except for the first folding groove and / or on the second surface of the UFG substrate layer except for the second folding groove; S4. Use an integrated molding process to form a first hardened buffer integrated layer on the surface of the obtained structure close to the screen end, covering the first surface of the UFG substrate layer and filling the first folding groove, and use an integrated molding process to form a second hardened buffer integrated layer on the surface of the obtained structure close to the client side, covering the second surface of the UFG substrate layer and filling the second folding groove; S5. Form an optical functional layer on the surface of the second hardened buffer integrated layer close to the client side.

9. The preparation method of the display screen cover plate structure according to claim 8, characterized in that: After step S2, it further includes a step of laser micro-nano polishing or local etching treatment on the first folding groove and the second folding groove, so that the first folding groove is a trapezoidal groove with a smaller upper part and a larger lower part along the direction from the screen end to the client side, the second folding groove is a trapezoidal groove with a larger upper part and a smaller lower part along the direction from the screen end to the client side, and the falling angles of the first folding groove and the second folding groove are both arc-shaped.

10. The manufacturing method of the display screen cover plate structure according to claim 8, characterized in that: After step S2, it further includes a step of thinning the UFG substrate layer corresponding to the first folding groove, so that the thickness of the UFG substrate layer corresponding to the second folding groove is greater than the thickness of the UFG substrate layer corresponding to the first folding groove.

11. The preparation method of the display screen cover plate structure according to claim 8, characterized in that: In step S3, a vapor deposition process or a magnetron sputtering process is used, combined with a photolithography etching process to form the touch conductive layer, and the annealing temperatures of the vapor deposition process and the magnetron sputtering process are both lower than 100°C.

12. The preparation method of the display screen cover plate structure according to claim 8, characterized in that, In step S3, the method for forming the touch conductive layer includes: S31. Form a first touch conductive layer on the first surface of the UFG substrate layer except for the first folding groove, and form a second touch conductive layer on the second surface of the UFG substrate layer except for the second folding groove; S32. Form a first wiring layer at the outer edge of the surface of the first touch conductive layer close to the screen end, and form a second wiring layer at the outer edge of the surface of the second touch conductive layer close to the client side.

13. The preparation method of the display screen cover plate structure according to claim 12, characterized in that: In step S31, it further includes the steps of forming a first grid-shaped conductive layer on the bottom wall and side walls of the first folding groove, and forming a second grid-shaped conductive layer on the bottom wall and side walls of the second folding groove, wherein the first grid-shaped conductive layer is in contact connection with the first touch conductive layer, and the second grid-shaped conductive layer is in contact connection with the second touch conductive layer.

14. The preparation method of the display screen cover plate structure according to claim 8, characterized in that, In step S3, the method of forming the touch conductive layer includes: S31, forming a third touch conductive layer on the second surface of the UFG substrate layer except for the second folding groove; S32, forming a third wiring layer at the outer edge of the surface of the third touch conductive layer close to the client.

15. The preparation method of the display screen cover plate structure according to claim 8, characterized in that: In step S4, the first hardening buffer integrated layer and the second hardening buffer integrated layer are formed by using a 3D printing process combined with a curing process. The solid content of the material used for the 3D printing process is 100%, and the method of the curing process is separate UV curing.

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