Display substrate and manufacturing method thereof

Abstract

The present application provides a display substrate and a method for preparing the same. The method includes providing a base substrate, the base substrate having a front side, a back side, and a side surface connected to the front side and the back side; a first circuit layer is provided on the back side, a second circuit layer is provided on the front side, and the base substrate includes a display area and a peripheral area; a flexible circuit film layer is formed in the peripheral area of ​​the base substrate, so that the flexible circuit film layer is electrically connected to the second circuit layer; a portion of the base substrate covered by the flexible circuit film layer is removed, so that a portion of the flexible circuit film layer extends beyond the edge of the base substrate to form a bent portion; the bent portion is bent to electrically connect to the first circuit layer, and the bent portion is aligned with the side surface. The present application solves the problem that the binding width and bending radius of existing flexible circuit boards are not conducive to the narrow-frame design of display devices.

Description

Technical Field

[0001] The present application relates to the field of display technology, and in particular to a display substrate and a method for preparing the same. Background Art

[0002] With the development of display technology, whether it is LCD (Liquid Crystal Display) display or Mini LED (sub-millimeter light-emitting diode), narrow frame design has become a development trend. Due to the limitations of existing technology, the display device needs to have a non-display area around it for electrical connection with the external drive device and for installation and fixation. For the non-display area, the current conventional design, such as Figure 1 As shown, one end of the flexible circuit board 100 is bonded to the display substrate 200, then bent to the back of the display substrate 200. The other end of the flexible circuit board 100 is connected to an external driver on the back of the display substrate 200. Due to the combined effect of the bond width between the flexible circuit board 100 and the display substrate 200 and the bending radius of the flexible circuit board 100, the width of the non-display area increases, which is not conducive to a narrow bezel design. Summary of the Invention

[0003] An embodiment of the present application provides a display substrate and a method for preparing the same. By forming a flexible circuit film layer on a base substrate, the flexible circuit film layer is bent to the back side of the base substrate and adhered to the side of the base substrate, thereby solving the problem that the binding width and bending radius of the existing flexible circuit board are not conducive to the narrow frame design of the display device.

[0004] The present invention is achieved by a method for preparing a display substrate, comprising:

[0005] Providing a base substrate, the base substrate having a front side, a back side, and a side surface connected to the front side and the back side; the back side is provided with a first circuit layer, the front side is provided with a second circuit layer, and the base substrate includes a display area and a peripheral area;

[0006] forming a flexible circuit film layer in the peripheral area of ​​the base substrate, so that the flexible circuit film layer is electrically connected to the second circuit layer;

[0007] removing a portion of the base substrate covered by the flexible circuit film layer, so that a portion of the flexible circuit film layer extends beyond an edge of the base substrate to form a bent portion;

[0008] The bent portion is bent to be electrically connected to the first circuit layer, and the bent portion is in contact with the side surface.

[0009] In one embodiment, the second circuit layer is a first metal circuit, and a flexible circuit film layer is formed in the peripheral area so that the flexible circuit film layer is electrically connected to the second circuit layer, including:

[0010] forming a first flexible film in the peripheral area so that the first flexible film covers the first metal circuit;

[0011] forming a via hole at a position of the first flexible film corresponding to the first metal circuit;

[0012] forming a flexible circuit layer on the first flexible film, wherein the flexible circuit layer covers the via hole and the first metal circuit;

[0013] A second flexible film is formed on the flexible circuit layer.

[0014] In one embodiment, the second circuit layer includes a third flexible film and a second metal circuit formed on the third flexible film, and a flexible circuit film layer is formed in the peripheral area so that the flexible circuit film layer is electrically connected to the second circuit layer, including:

[0015] forming a first flexible film in the peripheral area, wherein the first flexible film and the third flexible film are in the same layer and connected to each other;

[0016] forming a flexible circuit layer on the first flexible film, wherein the flexible circuit layer and the second metal circuit are in the same layer and are electrically connected to each other;

[0017] A second flexible film is formed on the flexible circuit layer.

[0018] In one embodiment, a microstructure is formed on a surface of the first flexible film away from the base substrate, and a microstructure is formed on a surface of the flexible circuit layer away from the first flexible film.

[0019] In one embodiment, the thickness of the first flexible film is equal to the thickness of the second flexible film.

[0020] In one embodiment, after providing the substrate, the method further includes:

[0021] A cutting protection layer is formed in the peripheral area, and the cutting protection layer is spaced apart from the second circuit layer.

[0022] In one embodiment, after removing a portion of the base substrate covered by the flexible circuit film layer so that a portion of the flexible circuit film layer extends beyond an edge of the base substrate to form a bent portion, the method further includes:

[0023] An adhesive layer is formed on the back surface and the side surface.

[0024] In one embodiment, the second flexible film does not cover the end portion of the bent portion bent to the back surface, and the end portion of the bent portion bent to the back surface is used for electrically connecting to a driving circuit.

[0025] The beneficial effect of the method for preparing a display substrate provided in the present application is that, compared with the prior art, a flexible circuit film layer is manufactured on a base substrate, and during the manufacturing process, one end of the flexible circuit film layer is electrically connected to the second circuit layer on the front side of the base substrate, the other end of the flexible circuit film layer is bent to the back side of the base substrate to electrically connect to the first circuit layer, and the portion of the flexible circuit film layer between the two ends is adhered to the side surface of the base substrate. This can reduce the connection length between the flexible circuit film layer and the front side of the base substrate. At the same time, because the portion of the flexible circuit film layer between the two ends is adhered to the side surface of the base substrate, the bending radius caused by bending a conventional flexible circuit board to the back side of the base substrate can be eliminated, thereby realizing a narrow-frame design for the display device.

[0026] An embodiment of the present application further provides a display substrate, which is prepared by the method described in any of the above embodiments.

[0027] In one embodiment, the flexible circuit film layer includes a first flexible film, a flexible circuit layer provided on the first flexible film, and a second flexible film covering the flexible circuit layer; the flexible circuit layer is used to electrically connect the second circuit layer to the first circuit layer.

[0028] In one embodiment, the surface of the flexible circuit layer has a microstructure, and the first flexible film and the second flexible film are both attached to the microstructure;

[0029] In one embodiment, the thickness of the first flexible film is equal to the thickness of the second flexible film.

[0030] The display substrate provided by the present application has the beneficial effect of being prepared using the preparation method of any of the above embodiments, by fabricating a flexible circuit film layer on a base substrate, and during the fabrication process electrically connecting one end of the flexible circuit film layer to the second circuit layer on the front side of the base substrate, bending the other end of the flexible circuit film layer to the back side of the base substrate to electrically connect to the first circuit layer, and laminating the portion of the flexible circuit film layer between the two ends to the side surface of the base substrate. This can reduce the connection length between the flexible circuit film layer and the front side of the base substrate. At the same time, because the portion of the flexible circuit film layer between the two ends is laminating to the side surface of the base substrate, the bending radius caused by bending a conventional flexible circuit board to the back side of the base substrate can be eliminated, thereby achieving a narrow-frame design for the display device. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1It is a schematic structural diagram of a display device in the prior art;

[0032] Figure 2 is a flow chart of a method for preparing a display substrate provided in Example 1 of the present application;

[0033] Figure 3 yes Figure 2 A flowchart of a specific embodiment of step S102;

[0034] Figure 4-1 1 is a schematic diagram of the device structure after step S101 is completed in the method for preparing a display substrate provided in Example 1 of the present application;

[0035] Figure 4-2 1 is a schematic diagram of the device structure after step S1022 of the method for preparing a display substrate provided in Example 1 of the present application is completed;

[0036] Figure 4-3 1 is a schematic diagram of the device structure after step S1023 of the method for preparing a display substrate provided in Example 1 of the present application is completed;

[0037] Figure 4-4 1 is a schematic diagram of the device structure after step S1024 is completed in the method for preparing a display substrate provided in Example 1 of the present application;

[0038] Figure 4-5 1 is a schematic diagram of the device structure after step S103 is completed in the method for preparing a display substrate provided in Example 1 of the present application;

[0039] Figure 4-6 1 is a schematic diagram of the device structure after step S104 is completed in the method for preparing a display substrate provided in Example 1 of the present application;

[0040] Figure 5-1 yes Figure 4-4 A schematic diagram of the structure of forming a cutting protection layer on the front surface of the middle substrate;

[0041] Figure 5-2 yes Figure 4-6 A schematic diagram of the structure of forming a cutting protection layer on the front surface of the middle substrate;

[0042] Figure 6 is a flow chart of a method for preparing a display substrate provided in Example 2 of the present application;

[0043] Figure 7-1 1 is a schematic diagram of the device structure after step S201 is completed in the method for preparing a display substrate provided in Example 2 of the present application;

[0044] Figure 7-2 2 is a schematic diagram of the device structure after step S202 of the method for preparing a display substrate provided in Example 2 of the present application is completed;

[0045] Figure 7-3 2 is a schematic diagram of the device structure after step S203 of the method for preparing a display substrate provided in Example 2 of the present application is completed;

[0046] Figure 7-4 2 is a schematic diagram of the device structure after step S204 is completed in the method for preparing a display substrate provided in Example 2 of the present application;

[0047] Figure 7-5 1 is a schematic diagram of the device structure after step S205 is completed in the method for preparing a display substrate provided in Example 2 of the present application;

[0048] Figure 7-6 2 is a schematic diagram of the device structure after step S206 is completed in the method for preparing a display substrate provided in Example 2 of the present application;

[0049] Figure 8-1 yes Figure 7-4 A schematic diagram of the structure of forming a cutting protection layer on the front surface of the middle substrate;

[0050] Figure 8-2 yes Figure 7-6 A schematic diagram of the structure of forming a cutting protection layer on the front surface of the middle substrate;

[0051] Figure 9 is a structural schematic diagram of a display substrate provided in Example 3 of the present application;

[0052] Figure 10 This is a schematic structural diagram of the display substrate provided in Example 4 of the present application.

[0053] Reference numerals: 10, base substrate; 11, front surface; 12, back surface; 13, side surface; 111, display area; 112, peripheral area;

[0054] 20. First circuit layer;

[0055] 30. Second circuit layer; 31. Third flexible film; 32. Second metal circuit;

[0056] 40. Flexible circuit film layer; 401. Bend portion; 41. First flexible film; 410. Microstructure; 42. Via hole; 43. Flexible circuit layer; 431. End portion; 44. Second flexible film;

[0057] 50. Cutting protective layer;

[0058] 70. Driving circuit; 80. Display device. DETAILED DESCRIPTION

[0059] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0060] It should be noted that when an element is referred to as being “fixed on” or “disposed on” another element, it may be directly on the other element or indirectly on the other element. When an element is referred to as being “connected to” another element, it may be directly connected to the other element or indirectly connected to the other element.

[0061] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0062] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. Throughout the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0063] It should also be noted that, in the embodiments of the present application, the same figure mark represents the same component or the same part. For the same parts in the embodiments of the present application, the figure may only mark one of the parts or components as an example. It should be understood that the figure mark also applies to other identical parts or components.

[0064] The embodiments of the present application provide a display substrate and a method for manufacturing the same, which solve the problem that the binding width and bending radius of the existing flexible circuit board are not conducive to the narrow frame design of the display device.

[0065] Example 1

[0066] refer to Figure 2 The method for preparing a display substrate provided in the first embodiment of the present application includes the following steps:

[0067] S101. Provide a base substrate 10, the base substrate 10 having a front side 11, a back side 12 arranged opposite to each other, and a side surface 13 connected to the front side 11 and the back side 12; the back side 12 is provided with a first circuit layer 20, the front side 11 is provided with a second circuit layer 30, and the base substrate 10 includes a display area 111 and a peripheral area 112.

[0068] Figure 4-1 Schematic diagram of the device structure after completing step S101. The substrate 10 can be made of glass, plastic, or other common materials in the art. The substrate 10 can be a carrier substrate for LCD, MiniLED, or MicroLED. In this embodiment, the side of the substrate 10 on which the device is prepared is the front side 11, and the opposite side is the back side 12. The front side 11 of the substrate 10 refers to the side surface of the substrate 10 used for light emission, and the back side 12 of the substrate 10 refers to the side surface of the substrate 10 away from the light emission, which is also the side of the substrate 10 used for driving the circuit 70. The side 13 of the substrate 10 refers to the side surface 13 of the substrate 10 located between the front side 11 and the back side 12.

[0069] The first circuit layer 20 on the back surface 12 of the substrate 10 and the second circuit layer 30 on the front surface 11 of the substrate 10 are fabricated using a semiconductor manufacturing process. Specifically, the first circuit layer 20 and the second circuit layer 30 can be fabricated using a physical vapor deposition (PVD) process. For example, the first circuit layer 20 and the second circuit layer 30 can be fabricated using a magnetron sputtering process. Both the first circuit layer 20 and the second circuit layer 30 can be fabricated using a conductive metal material such as aluminum, copper, or molybdenum.

[0070] The second circuit layer 30 is electrically connected to the display device 80 provided in the display area 111 of the base substrate 10. The driving circuit 70 can be installed on the first circuit layer 20. The driving circuit 70 can be prepared at the same time as the first circuit layer 20 is prepared. This can improve the production efficiency of the display substrate and enhance the electrical connection performance between the first circuit layer 20 and the driving circuit 70. Of course, the driving circuit 70 can also be a circuit structure independent of the base substrate 10, and the driving circuit 70 can be connected to the first circuit layer 20 after the first circuit layer 20 is prepared. This is not specifically limited in this embodiment of the present application.

[0071] S102 , forming a flexible circuit film layer 40 in the peripheral area 112 of the base substrate 10 , so that the flexible circuit film layer 40 is electrically connected to the second circuit layer 30 .

[0072] The flexible circuit film layer 40 in step S102 is manufactured using a semiconductor process. The flexible circuit film layer 40 is flexible and bendable, and also conductive. Directly placing the flexible circuit film layer 40 on the peripheral region 112 of the base substrate 10 ensures complete adhesion to the base substrate 10, thereby providing a good electrical connection to the second circuit layer 30. Furthermore, the flexible circuit film layer 40 and the base substrate 10 form a single, integrated whole, preventing separation during use.

[0073] In addition, compared with the prior art of binding a flexible circuit board to a display substrate, which requires a wider binding width to electrically connect the flexible circuit board to the circuit layer of the display substrate, the present application directly manufactures the flexible circuit film layer 40 on the base substrate 10. In this way, the length required for the electrical connection between the flexible circuit film layer 40 and the second circuit layer 30 is greatly reduced, which is conducive to reducing the connection length between the flexible circuit film layer 40 and the front surface 11 of the base substrate 10, thereby realizing a narrow frame design of the display device.

[0074] S103 , removing a portion of the base substrate 10 covered by the flexible circuit film layer 40 , so that a portion of the flexible circuit film layer 40 extends beyond the edge of the base substrate 10 , to form a bent portion 401 .

[0075] Figure 4-5 Figure 1 is a schematic diagram of the device structure after step S103. Laser lift-off and cutting are used to remove a portion of the base substrate 10 covered by the flexible circuit film layer 40. This not only allows the base substrate 10 to be cut away, but also allows it to be separated from the flexible film. Specifically, cutting can be performed simultaneously on both the back surface 12 and the side surface 13 of the base substrate 10, effectively accelerating the cutting process while better protecting the base substrate 10 and the flexible circuit film layer 40.

[0076] The flexible circuit film layer 40 and the second circuit layer 30 are directly electrically connected during manufacture, so that there is no need for the flexible circuit film layer 40 and the front surface 11 of the base substrate 10 to have an excessively long bonding length. Therefore, while ensuring that the flexible circuit film layer 40 and the second circuit layer 30 maintain a good electrical connection, as much of the base substrate 10 as possible can be cut. This helps to reduce the bonding length between the flexible circuit film layer 40 and the front surface 11 of the base substrate 10, which is conducive to the design of a narrow frame of the display device.

[0077] like Figure 5-1 and Figure 5-2As shown, to prevent burns to the second circuit layer 30 during laser operation, a cutting protection layer 50 can be provided in the cutting area to block damage to the second circuit layer 30 caused by the laser energy. After completing step S101, the cutting protection layer 50 can be formed in the peripheral area 112, and the cutting protection layer 50 is spaced apart from the second circuit layer 30. In the embodiment of the present application, the second circuit layer 30 can be a first metal circuit, and the cutting protection layer 50 is made of a metal material. In this way, the second circuit layer 30 and the cutting protection layer 50 can be provided in the same layer using the same metal material, which can effectively improve the production efficiency of the display substrate.

[0078] It should be noted that the length of the cutting protection layer 50 needs to be equal to the cutting line, and the width of the cutting protection layer 50 needs to be at least 1.5 times the diameter of the optical spot. This way, when cutting the base substrate 10, once the cutting protection layer 50 is cut, the cutting is completed. This prevents the flexible circuit film layer 40 from being cut, and does not damage its conductive properties. The cutting protection layer 50 also effectively indicates the correct cutting position, preventing multiple cuts. A clear boundary area must be formed between the cutting protection layer 50 and the second circuit layer 30 to prevent corrosion from the cutting protection layer 50 from spreading and affecting the second circuit layer 30.

[0079] S104 , bend the bent portion 401 to be electrically connected to the first circuit layer 20 , and the bent portion 401 is in contact with the side surface 13 .

[0080] Figure 4-6 Figure 4 is a schematic diagram of the device structure after step S104. Bend portion 401 is bent onto back surface 12 of substrate 10 to electrically connect to first circuit layer 20, thereby allowing flexible circuit film layer 40 to electrically connect first circuit layer 20 and second circuit layer 30. The alignment of bend portion 401 with side surface 13 eliminates the bending radius created by conventional flexible circuit boards bending onto back surface 12 of substrate 10, thereby achieving a narrow-frame design for the display device.

[0081] It should be noted that the specific method of electrically connecting the bent portion 401 and the first circuit layer 20 may be to directly electrically connect the bent portion 401 and the first circuit layer 20 together through a wire.

[0082] The bending portion 401 is bent to the back side 12 of the base substrate 10 and fits with both the back side 12 and the side 13. In order to enhance the adhesion strength between the bending portion 401 and the back side 12 and the side 13, after completing step S103, adhesive can be sprayed on the back side 12 and the side 13 to form an adhesive layer. In this way, after the bending portion 401 is bent, it can be tightly connected to the back side 12 and the side 13 through the adhesive layer, and the bending angle of the bending portion 401 can be increased, thereby reducing the bending stress.

[0083] In some embodiments, the second flexible film 44 does not cover the end 431 where the bent portion 401 bends to the back surface 12. The end 431 of the bent portion 401 bent to the back surface 12 is used to electrically connect to the drive circuit 70. This allows the flexible circuit film layer 40 to be quickly and electrically connected to the drive circuit 70 after the bent portion 401 is bent to the back surface 12 of the base substrate 10 without requiring additional operation. The drive circuit 70 can be directly connected to the first circuit layer 20 or provided separately, which is not specifically limited in this embodiment of the present application.

[0084] The above-mentioned method for preparing a display substrate comprises forming a flexible circuit film layer 40 on a base substrate 10. During the manufacturing process, one end of the flexible circuit film layer 40 is electrically connected to the second circuit layer 30 on the front surface 11 of the base substrate 10, and the other end of the flexible circuit film layer 40 is bent to the back surface 12 of the base substrate 10 to electrically connect to the first circuit layer 20. The portion of the flexible circuit film layer 40 between the two ends is adhered to the side surface 13 of the base substrate 10. This increases the overall adhesion length between the flexible circuit film layer 40 and the base substrate 10, thereby reducing the connection length between the flexible circuit film layer 40 and the front surface 11 of the base substrate 10 while ensuring a secure connection between the flexible circuit film layer 40 and the base substrate 10. At the same time, because the portion of the flexible circuit film layer 40 between the two ends is adhered to the side surface 13 of the base substrate 10, the bending radius caused by bending a conventional flexible circuit board to the back surface 12 of the base substrate 10 can be eliminated, thereby achieving a narrow-frame design for the display device.

[0085] For further reference, Figure 3 When the second circuit layer 30 is a first metal circuit, step S102 includes the following steps:

[0086] S1021 , forming a first flexible film 41 in the peripheral area 112 , so that the first flexible film 41 covers the first metal circuit.

[0087] The first flexible film 41 can be made of a general flexible material, such as polyimide. The first flexible film 41 can also be made of a flexible polymer material. The flexible polymer material has good flexibility and can improve the flexibility of the flexible circuit film layer 40, making it easier for the flexible circuit film layer 40 to be attached to the base substrate 10.

[0088] S1022 , forming a via hole 42 at a position of the first flexible film 41 corresponding to the first metal circuit.

[0089] Figure 4-2 Schematic diagram of the device structure after step S1022 is completed. The first flexible film 41 can be patterned by a photolithography process (resin coating, exposure, development, etching, and resist removal) to obtain a via 42 connected to the first metal circuit.

[0090] In addition, a microstructure 410 is formed on the surface of the first flexible film 41 facing away from the base substrate 10. Thus, a portion of the surface of the first flexible film 41 facing away from the base substrate 10 is uneven. Specifically, the structure after step S1022 can be placed in an etching solution to etch grooves on the surface of the first flexible film 41 facing away from the base substrate 10. The grooves can be arc-shaped or square-shaped, so that the areas between the grooves form protrusions. The protrusions and grooves thus form the microstructure 410.

[0091] S1023 , forming a flexible circuit layer 43 on the first flexible film 41 , wherein the flexible circuit layer 43 covers the via hole 42 and the first metal circuit.

[0092] Figure 4-3 The flexible circuit layer 43 can be made of conventional conductive metal materials such as copper, aluminum, molybdenum and laminates thereof, or can be made of novel flexible conductive materials such as nanosilver, graphene and the like.

[0093] When preparing the flexible circuit layer 43, a metal conductive layer can be deposited entirely on the first flexible film 41. This metal conductive layer is deposited on the walls of the vias 42 and in the grooves of the microstructures 410. The metal conductive layer is then patterned to form the flexible circuit layer 43. This electrically connects the flexible circuit layer 43 to the second circuit layer 30. Furthermore, the concave-convex surface between the flexible circuit layer 43 and the first flexible film 41 significantly increases the adhesion area between the flexible circuit layer 43 and the first flexible film 41, reducing the risk of delamination.

[0094] Optionally, the flexible circuit layer 43 can be formed in the same layer as the second metal layer of the array substrate, that is, manufactured through the same process, which can save process and cost. In other words, in this embodiment, the multiple film layers of the flexible circuit film layer 40 and the film layers of the display area 111 share the same process, thereby significantly improving production efficiency, process, cost, and manufacturing time.

[0095] Furthermore, a microstructure 410 is also formed on a surface of the flexible circuit layer 43 that is away from the first flexible film 41 .

[0096] S1024 , forming a second flexible film 44 on the flexible circuit layer 43 .

[0097] Figure 4-4 Schematic diagram of the device structure after step S1024 is completed. The second flexible film 44 can be made of a general flexible material, such as polyimide. The second flexible film 44 can also be made of a flexible polymer material. Flexible polymer materials have good flexibility and can improve the flexibility of the flexible circuit film layer 40, facilitating the bonding of the flexible circuit film layer 40 to the base substrate 10.

[0098] The first flexible film 41, flexible circuit layer 43, and second flexible film 44 form the flexible circuit film layer 40. Because the surface of the flexible circuit layer 43 facing away from the first flexible film 41 also has microstructures 410, the contact surface between the second flexible film 44 and the flexible circuit layer 43 also has a concave-convex structure. This increases the adhesion area between the flexible circuit layer 43 and the second flexible film 44, reducing the risk of delamination. Furthermore, the concave-convex contact surface between the film layers balances the tensile and compressive stresses caused by the internal bending of the flexible circuit film layer 40 when it bends, reducing the risk of cracking in the flexible circuit film layer 40.

[0099] In addition, since the flexible circuit film layer 40 needs to be attached to the back side 12 and the side surface 13 of the base substrate 10, in order to reduce the problems of delamination and cracking of the first flexible film 41, the flexible circuit layer 43 and the second flexible film 44 caused by bending stress when the flexible circuit film layer 40 is bent, the thickness of the first flexible film 41 and the thickness of the second flexible film 44 can be set to be equal. In this way, the flexible circuit layer 43 is located in the middle position of the flexible circuit film layer 40, so that the stress of the flexible circuit layer 43 during the bending process is minimized, and it is easier to bend without breaking.

[0100] Example 2

[0101] refer to Figure 6 The method for preparing a display substrate provided in the second embodiment of the present application includes the following steps:

[0102] S201. Provide a base substrate 10. The base substrate 10 has a front surface 11 and a back surface 12 disposed opposite to each other, and a side surface 13 connected to the front surface 11 and the back surface 12. The back surface 12 is provided with a first circuit layer 20, and the front surface 11 is provided with a second circuit layer 30. The second circuit layer 30 includes a third flexible film 31 and a second metal circuit 32 formed on the third flexible film 31. The base substrate 10 includes a display area 111 and a peripheral area 112.

[0103] Figure 7-1Schematic diagram of the device structure after step S201 is completed. A first circuit layer 20 is fabricated on the back surface 12 of the substrate 10 using a semiconductor process. The first circuit layer 20 can be fabricated using conductive metal materials such as aluminum, copper, and molybdenum. A second circuit layer 30 is fabricated on the front surface 11 of the substrate 10 using a semiconductor process. Specifically, a third flexible film 31 can be first deposited on the front surface 11 of the substrate 10, and then a second metal circuit 32 can be fabricated on the third flexible film 31 to form the second circuit layer 30. The third flexible film 31 can be fabricated using a general-purpose flexible material, such as polyimide. Alternatively, the third flexible film 31 can be fabricated using a flexible polymer material. Flexible polymer materials offer greater flexibility, facilitating adhesion of the third flexible film 31 to the substrate 10. The second metal circuit 32 can be fabricated using conductive metal materials such as aluminum, copper, and molybdenum.

[0104] S202 , forming a first flexible film 41 in the peripheral area 112 . The first flexible film 41 and the third flexible film 31 are in the same layer and connected to each other.

[0105] Figure 7-2 The first flexible film 41 and the third flexible film 31 can be made of the same material and can be deposited simultaneously during deposition, which can improve the production efficiency of the display substrate.

[0106] S203 , forming a flexible circuit layer 43 on the first flexible film 41 , wherein the flexible circuit layer 43 and the second metal circuit 32 are in the same layer and electrically connected to each other.

[0107] Figure 7-3 Figure 1 is a schematic diagram of the device structure after step S203. The flexible circuit layer 43 and the second metal circuit 32 can be provided simultaneously. Specifically, a full metal conductive layer can be deposited on the first flexible film 41 and the third flexible film 31. The metal conductive layer in the display area 111 is patterned to form the second metal circuit 32, and the metal conductive layer in the peripheral area 112 is patterned to form the flexible circuit layer 43. This effectively simplifies the display substrate manufacturing process and improves display substrate production efficiency.

[0108] S204 , forming a second flexible film 44 on the flexible circuit layer 43 , so that the first flexible film 41 , the flexible circuit layer 43 , and the second flexible film 44 form a flexible circuit film.

[0109] Figure 7-4 Schematic diagram of the device structure after step S204 is completed. The second flexible film 44 can be made of a general flexible material, such as polyimide. The second flexible film 44 can also be made of a flexible polymer material. Flexible polymer materials have good flexibility and can improve the flexibility of the flexible circuit film layer 40, facilitating the bonding of the flexible circuit film layer 40 to the base substrate 10.

[0110] A microstructure 410 is formed on the surface of the first flexible film 41 facing away from the substrate 10, creating a partially uneven surface. The microstructure 410 is also formed on the surface of the flexible circuit layer 43 facing away from the first flexible film 41. As a result, the bonding surfaces of the flexible circuit layer 43, the first flexible film 41, and the second flexible film 44 each have a concave-convex structure. This significantly increases the adhesion area between the flexible circuit layer 43, the first flexible film 41, and the second flexible film 44, effectively reducing the risk of delamination. Furthermore, the concave-convex bonding surfaces between the film layers balance the tensile and compressive stresses caused by the internal bending of the flexible circuit film layer 40 when it bends, reducing the risk of cracking in the flexible circuit film layer 40.

[0111] The specific implementation of forming the microstructure 410 on the surface of the first flexible film 41 away from the substrate 10 and forming the microstructure 410 on the surface of the flexible circuit layer 43 away from the first flexible film 41 can refer to the first embodiment and will not be repeated here.

[0112] S205 , removing a portion of the base substrate 10 covered by the flexible circuit film layer 40 , so that a portion of the flexible circuit film layer 40 extends beyond the edge of the base substrate 10 to form a bent portion 401 .

[0113] Figure 7-5 Schematic diagram of the device structure after completing step S205.

[0114] like Figure 8-1 and Figure 8-2 As shown, to prevent burns to the second circuit layer 30 during laser operation, a cutting protection layer 50 can be provided in the cutting area to block laser energy from damaging the second circuit layer 30. After completing step S201, the cutting protection layer 50 is formed in the peripheral area 112, spaced apart from the second circuit layer 30. If the third flexible film 31 and the first flexible film 41 are provided simultaneously, the cutting protection layer 50 must first be formed on the front surface 11 of the base substrate 10, followed by the third flexible film 31 and the first flexible film 41, with the first flexible film 41 covering the cutting protection layer 50.

[0115] S206 , bend the bent portion 401 to be electrically connected to the first circuit layer 20 , and the bent portion 401 is in contact with the side surface 13 .

[0116] Figure 7-6This is a schematic diagram of the device structure after step S206. Bend portion 401 is bent onto back surface 12 of substrate 10 to electrically connect to first circuit layer 20, thereby allowing flexible circuit film layer 40 to electrically connect first circuit layer 20 and second circuit layer 30. The alignment of bend portion 401 with side surface 13 eliminates the bending radius created by conventional flexible circuit boards bending onto back surface 12 of substrate 10, thereby achieving a narrow-frame design for the display device.

[0117] The bending portion 401 is bent to the back side 12 of the base substrate 10 and fits with both the back side 12 and the side 13. In order to enhance the adhesion strength between the bending portion 401 and the back side 12 and the side 13, after completing step S205, adhesive can be sprayed on the back side 12 and the side 13 to form an adhesive layer. In this way, after the bending portion 401 is bent, it can be tightly connected to the back side 12 and the side 13 through the adhesive layer, and the bending angle of the bending portion 401 can be increased, thereby reducing the bending stress.

[0118] Example 3

[0119] refer to Figure 9 The display substrate provided in the third embodiment of the present application is prepared according to the method of the above-mentioned first embodiment. Specifically, the display substrate provided in the third embodiment of the present application includes a base substrate 10 and a flexible circuit film layer 40. The base substrate 10 has a front surface 11, a back surface 12 arranged opposite to each other, and a side surface 13 connected to the front surface 11 and the back surface 12; the back surface 12 is provided with a first circuit layer 20, and the front surface 11 is provided with a second circuit layer 30, the second circuit layer 30 is a first metal circuit, and the base substrate 10 includes a display area 111 and a peripheral area 112; the flexible circuit film layer 40 is provided in the peripheral area 112 of the base substrate 10, one end of the flexible circuit film layer 40 is electrically connected to the second circuit layer 30, and the other end is electrically connected to the first circuit layer 20, and the portion of the flexible circuit film layer 40 between the two ends is in contact with the side surface 13.

[0120] By manufacturing a flexible circuit film layer 40 on a base substrate 10, and during the manufacturing process electrically connecting one end of the flexible circuit film layer 40 to the second circuit layer 30 on the front surface 11 of the base substrate 10, and bending the other end of the flexible circuit film layer 40 to the back surface 12 of the base substrate 10 to electrically connect to the first circuit layer 20, and laminating the portion of the flexible circuit film layer 40 between the two ends to the side surface 13 of the base substrate 10, the connection length between the flexible circuit film layer 40 and the front surface 11 of the base substrate 10 can be reduced while ensuring a secure connection between the flexible circuit film layer 40 and the base substrate 10. At the same time, because the portion of the flexible circuit film layer 40 between the two ends is laminating to the side surface 13 of the base substrate 10, the bending radius generated by bending a conventional flexible circuit board to the back surface 12 of the base substrate 10 can be eliminated, thereby achieving a narrow-frame design for the display device.

[0121] like Figure 9 As shown, in some embodiments, the flexible circuit film layer 40 includes a first flexible film 41, a flexible circuit layer 43 disposed on the first flexible film 41, and a second flexible film 44 covering the flexible circuit layer 43. The flexible circuit layer 43 is used to electrically connect the second circuit layer 30 to the first circuit layer 20. This improves the flexibility of the flexible circuit film layer 40, facilitating better adhesion between the flexible circuit film layer 40 and the substrate 10. Furthermore, the covering of the flexible circuit layer 43 by the first flexible film 41 and the second flexible film 44 can reduce the bending stress of the flexible circuit layer 43 when the flexible circuit film layer 40 is bent, thereby reducing the risk of fracture of the flexible circuit layer 43.

[0122] like Figure 9 As shown, the display device 80 can be mounted on the second circuit layer 30 , and the end portion 431 of the flexible circuit layer 43 not covered by the second flexible film 44 is electrically connected to the driving circuit 70 .

[0123] like Figure 9 As shown, in some embodiments, the surface of the flexible circuit layer 43 has microstructures 410, and both the first flexible film 41 and the second flexible film 44 are bonded to the microstructures 410. Thus, the bonding surfaces of the flexible circuit layer 43 with the first flexible film 41 and the second flexible film 44 each have a concave-convex structure, significantly increasing the adhesion area between the flexible circuit layer 43, the first flexible film 41 and the second flexible film 44, and effectively reducing the risk of delamination. Furthermore, the concave-convex bonding surfaces between the film layers balance the tensile and compressive stresses caused by the internal bending of the flexible circuit film layer 40 when it bends, reducing the risk of cracking in the flexible circuit film layer 40.

[0124] In some embodiments, the thickness of the first flexible film 41 is equal to the thickness of the second flexible film 44 .

[0125] Since the flexible circuit film layer 40 needs to be attached to the back surface 12 and the side surface 13 of the base substrate 10, in order to reduce the delamination and cracking of the first flexible film 41, the flexible circuit layer 43, and the second flexible film 44 caused by bending stress when the flexible circuit film layer 40 is bent, the thickness of the first flexible film 41 and the thickness of the second flexible film 44 can be set to be equal. In this way, the flexible circuit layer 43 is located in the middle of the flexible circuit film layer 40, which minimizes the stress of the flexible circuit layer 43 during the bending process, making it easier to bend without breaking.

[0126] It should be noted that the thickness of the first flexible film 41 and the second flexible film 44 are both less than 0.01 mm. The smaller the thickness of the first flexible film 41 and the second flexible film 44, the smaller the thickness of the entire flexible circuit film layer 40, which is beneficial to improving the flexibility of the entire flexible circuit film layer 40, reducing the bonding stress of the flexible circuit film layer 40, and improving the bonding effect of the flexible circuit film layer 40 on the base substrate 10.

[0127] In some embodiments, the thickness of the flexible circuit layer 43 ranges from 0.005 mm to 0.015 mm. Specifically, the thickness of the flexible circuit layer 43 can be 0.005 mm, 0.01 mm, or 0.015 mm. This embodiment, by limiting the thickness range of the flexible circuit layer 43, not only ensures the conductive performance of the flexible circuit layer 43, but also reduces the hardness of the flexible circuit layer 43, thereby not affecting the flexibility of the entire flexible circuit film layer 40.

[0128] Example 4

[0129] refer to Figure 10 The display substrate provided in the fourth embodiment of the present application is prepared according to the method of the above-mentioned second embodiment. Compared with the display substrate provided in the third embodiment, the difference lies in the structure of the second circuit layer 30. In the display substrate provided in the fourth embodiment of the present application, the second circuit layer 30 includes a third flexible film 31 and a second metal circuit 32 formed on the third flexible film 31.

[0130] It should be noted that, through the above arrangement, the third flexible film 31 and the first flexible film 41 can be prepared together in the same layer, and the second metal circuit 32 and the flexible circuit layer 43 can also be prepared together in the same layer, which greatly improves the preparation efficiency of the display substrate.

[0131] like Figure 10 As shown, the display device 80 can be mounted on the second circuit layer 30 , and the end portion 431 of the flexible circuit layer 43 not covered by the second flexible film 44 is electrically connected to the driving circuit 70 .

[0132] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A method for preparing a display substrate, characterized in that: include: A base substrate (10) is provided, wherein the base substrate (10) has a front surface (11), a back surface (12) and a side surface (13) connected to the front surface (11) and the back surface (12); the back surface (12) is provided with a first circuit layer (20), the front surface (11) is provided with a second circuit layer (30), and the base substrate (10) includes a display area (111) and a peripheral area (112); forming a cutting protection layer (50) in the peripheral area (112), wherein the cutting protection layer (50) and the second circuit layer (30) are spaced apart from each other; A flexible circuit film layer (40) is formed in the peripheral area (112) of the base substrate (10), the flexible circuit film layer (40) comprising a first flexible film (41), a flexible circuit layer (43) provided on the first flexible film (41), and a second flexible film (44) covering the flexible circuit layer (43), the flexible circuit layer (43) being electrically connected to the second circuit layer (30), a microstructure (410) being formed on a surface of the first flexible film (41) away from the base substrate (10), a microstructure (410) being formed on a surface of the flexible circuit layer (43) away from the first flexible film (41), and the thickness of the first flexible film (41) being equal to the thickness of the second flexible film (44); removing a portion of the base substrate (10) covered by the flexible circuit film layer (40), so that a portion of the flexible circuit film layer (40) extends beyond the edge of the base substrate (10) to form a bent portion (401); The bent portion (401) is bent to be electrically connected to the first circuit layer (20), and the bent portion (401) is in contact with the side surface (13).

2. The method according to claim 1, characterized in that The second circuit layer (30) is a first metal circuit, and a flexible circuit film layer (40) is formed in the peripheral area (112), so that the flexible circuit film layer (40) is electrically connected to the second circuit layer (30), comprising: forming a first flexible film (41) in the peripheral area (112), so that the first flexible film (41) covers the first metal circuit; forming a via hole (42) at a position of the first flexible film (41) corresponding to the first metal circuit; forming a flexible circuit layer (43) on the first flexible film (41), wherein the flexible circuit layer (43) covers the via hole (42) and the first metal circuit; A second flexible film (44) is formed on the flexible circuit layer (43).

3. The method according to claim 1, characterized in that The second circuit layer (30) includes a third flexible film (31) and a second metal circuit (32) formed on the third flexible film (31), and a flexible circuit film layer (40) is formed in the peripheral area (112), so that the flexible circuit film layer (40) is electrically connected to the second circuit layer (30), including: A first flexible film (41) is formed in the peripheral area (112), wherein the first flexible film (41) and the third flexible film (31) are in the same layer and are connected to each other; forming a flexible circuit layer (43) on the first flexible film (41), wherein the flexible circuit layer (43) and the second metal circuit (32) are in the same layer and are electrically connected to each other; A second flexible film (44) is formed on the flexible circuit layer (43).

4. The method according to any one of claims 1 to 3, characterized in that After removing a portion of the base substrate (10) covered by the flexible circuit film layer (40) so that a portion of the flexible circuit film layer (40) extends beyond the edge of the base substrate (10) to form a bent portion (401), the method further comprises: An adhesive layer is formed on the back surface (12) and the side surface (13).

5. The method according to claim 2 or 3, characterized in that The second flexible film (44) does not cover the end portion (431) where the bending portion (401) is bent to the back surface (12), and the end portion (431) where the bending portion (401) is bent to the back surface (12) is used for electrically connecting to a driving circuit (70).

6. A display substrate, characterized in that: The display substrate is prepared by the method according to any one of claims 1 to 5.

7. The display substrate according to claim 6, wherein: The flexible circuit film layer (40) comprises a first flexible film (41), a flexible circuit layer (43) provided on the first flexible film (41), and a second flexible film (44) covering the flexible circuit layer (43); the flexible circuit layer (43) is used to electrically connect the second circuit layer (30) to the first circuit layer (20).

8. The display substrate according to claim 7, wherein: The surface of the flexible circuit layer (43) has a microstructure (410), and the first flexible film (41) and the second flexible film (44) are both adhered to the microstructure (410); And / or, the thickness of the first flexible film (41) is equal to the thickness of the second flexible film (44).

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