Display panel, method for manufacturing display panel, and display device

Abstract

The present application provides a display panel, a method for manufacturing a display panel, and a display device. The display panel includes a bending region and at least two planar regions, with two adjacent planar regions connected by the bending region. The display panel includes an array substrate, an OLED light-emitting layer, and a Micro LED light-emitting layer. The OLED light-emitting layer is distributed on the array substrate located in the planar region, and the Micro LED light-emitting layer is distributed on the array substrate located in the bending region. The bending stress of the display panel located in the bending region is less than the bending stress of the display panel located in the planar region. Therefore, the display panel, method for manufacturing a display panel, and display device provided in embodiments of the present application can reduce the bending stress of the display panel in the bending region, thereby reducing the risk of delamination between functional film layers in the display panel in the bending region, thereby ensuring the display effect of the display panel and the display device.

Description

Technical Field

[0001] The present application relates to the technical field of display devices, and in particular to a display panel, a method for manufacturing a display panel, and a display device. Background Art

[0002] Flexible display panels offer a variety of unique product forms, including folding, large-angle bending, and curling, leading to their increasing application. For example, foldable display panels offer a larger display area when flattened, while folded, making display devices featuring them compact and portable, attracting widespread attention.

[0003] In related art, a display panel includes a bending area and two planar areas, which are connected by the bending area. The display panel in the planar area can be flat, and the display panel in the bending area can be bent, thereby realizing the folding function of the display panel.

[0004] However, the display panel in the bending area is subjected to a large bending stress during the bending process, which causes the functional film layers of the display panel to be easily peeled off, thereby affecting the display effect of the display panel. Summary of the Invention

[0005] In view of the above problems, the embodiments of the present application provide a display panel, a method for preparing a display panel, and a display device, which can reduce the bending stress of the display panel in the bending area, thereby reducing the risk of peeling between the various functional film layers in the display panel in the bending area, so as to ensure the display effect of the display panel and the display device.

[0006] In order to achieve the above objectives, the embodiments of the present application provide the following technical solutions:

[0007] A first aspect of the present application provides a display panel, comprising a bending region and at least two planar regions, wherein two adjacent planar regions are connected by the bending region, and the display panel comprises an array substrate, an OLED light-emitting layer, and a Micro LED light-emitting layer;

[0008] The OLED light-emitting layer is distributed on the array substrate located in the flat area, and the Micro LED light-emitting layer is distributed on the array substrate located in the bending area;

[0009] The bending stress of the display panel located in the bending area is smaller than the bending stress of the display panel located in the flat area.

[0010] The display panel provided in the embodiment of the present application adopts an OLED light-emitting layer in the flat area of ​​the display panel, and a Micro LED light-emitting layer in the bending area of ​​the display panel. When bent, the display panel made of Micro LED can be subjected to lower bending stress than the display panel made of OLED. The use of the Micro LED light-emitting layer in the bending area and the OLED light-emitting layer in the flat area can make the bending stress of the display panel in the bending area less than the bending stress of the display panel in the flat area, thereby improving the bending resistance of the display panel to ensure the display effect of the display panel and the display device. In addition, the OLED light-emitting layer is used in the flat area, and the Micro LED light-emitting layer is used only in a small area of ​​the bending area. There is no need to transfer Micro LEDs over a large area, which can get rid of the dilemma of low yield of large-scale transfer of Micro LEDs.

[0011] In one possible implementation, the device further includes an encapsulation layer, the encapsulation layer including a first encapsulation layer and a second encapsulation layer, the first encapsulation layer being located on a side of the OLED light-emitting layer away from the array substrate, and the second encapsulation layer being located on a side of the Micro LED light-emitting layer away from the array substrate;

[0012] The bending stress of the second packaging layer is smaller than the bending stress of the first packaging layer.

[0013] In this way, the bending stress of the second encapsulation layer is relatively small, which can reduce the bending stress of the display panel in the bending area, improve the folding resistance of the display panel, and ensure the display effect of the display panel and the display device.

[0014] In one possible implementation, the Micro LED light-emitting layer includes a plurality of Micro LED light-emitting units arranged in an array, the OLED light-emitting layer includes a plurality of OLED light-emitting units arranged in an array, and the distribution density of the Micro LED light-emitting units in the Micro LED light-emitting layer is less than the distribution density of the OLED light-emitting units in the OLED light-emitting layer.

[0015] What can be achieved is that the sum of the thickness of the first encapsulation layer and the OLED light-emitting layer is greater than the sum of the thickness of the second encapsulation layer and the MicroLED light-emitting layer.

[0016] In this way, the sum of the thicknesses of the second encapsulation layer and the Micro LED light-emitting layer is smaller, which can reduce the bending stress of the display panel in the bending area and improve the folding resistance of the display panel to ensure the display effect of the display panel and the display device.

[0017] In a possible implementation, the device further includes a cover plate and a polarizing layer, wherein the cover plate is located on a side of the first encapsulation layer and the second encapsulation layer away from the array substrate;

[0018] The polarizing layer is located between the cover plate and the first packaging layer.

[0019] In this way, no polarizing layer is provided between the second encapsulation layer and the cover plate, which can reduce the thickness of the display panel in the bending area, thereby reducing the bending stress of the display panel in the bending area and improving the folding resistance of the display panel.

[0020] In a possible implementation, a light-transmitting filling layer is further included, and the light-transmitting filling layer is located between the cover plate and the second encapsulation layer;

[0021] and / or,

[0022] The cover plate includes a first cover plate portion and a second cover plate portion connected to each other, the thickness of the first cover plate portion is not greater than the thickness of the second cover plate portion, and the surfaces of the first cover plate portion and the second cover plate portion away from the array substrate are flush;

[0023] The first cover portion is located on a side of the first packaging layer away from the array substrate, and the second cover portion is located on a side of the second packaging layer away from the array substrate.

[0024] In this way, the surface flatness of the display panel is better and the display effect is better.

[0025] In a possible implementation, the entire thickness of the cover plate is uniform, and a surface of the cover plate located in the bending region and close to the array substrate is attached to the second packaging layer;

[0026] The surface of the cover plate located in the bending area and away from the array substrate is lower than the surface of the cover plate located in the flat area and away from the array substrate.

[0027] In this way, the display panel in the bending area is thinner as a whole, and its bending stress is smaller. The overall thickness of the cover plate is consistent, and the manufacturing process of the cover plate is relatively simple.

[0028] In a possible implementation, the array substrate includes a substrate and a plurality of driving units disposed on the substrate, wherein the plurality of driving units are arranged in an array;

[0029] The arrangement density of the metal traces in the driving unit located in the planar area is greater than the arrangement density of the metal traces in the driving unit located in the bending area;

[0030] What can be achieved is that the width-to-length ratio of the gate signal line of the driving unit located in the planar area is greater than the width-to-length ratio of the gate signal line of the driving unit located in the bending area.

[0031] In this way, the bending stress on the array substrate in the bending area when it is bent can be reduced, thereby avoiding the problem of interlayer peeling of the array substrate in the bending area when it is bent, and improving the stability of the array substrate structure.

[0032] In one possible implementation, the driving unit located in the bending area includes a first pole connecting line, a second pole connecting line, a light-emitting signal line, and a common line. The first end of the first pole connecting line is connected to the light-emitting signal line, the second end of the first pole connecting line is connected to the first pole of the Micro LED light-emitting layer, the first end of the second pole connecting line is connected to the common line, and the second end of the second pole connecting line is connected to the second pole of the Micro LED light-emitting layer.

[0033] In this way, electrical connection between the Micro LED light-emitting layer and the driving unit is achieved.

[0034] A second aspect of the embodiments of the present application provides a method for manufacturing a display panel, wherein the display panel includes a bending region and at least two planar regions, wherein two adjacent planar regions are connected by the bending region;

[0035] The method for preparing a display panel includes:

[0036] An array substrate is provided; the array substrate includes a substrate and a plurality of driving units disposed on the substrate, wherein the plurality of driving units are arranged in an array;

[0037] A Micro LED light-emitting layer is formed on the array substrate in the bending region, and a second encapsulation layer is formed on a side of the Micro LED light-emitting layer away from the array substrate; the Micro LED light-emitting layer is electrically connected to the driving unit in the bending region;

[0038] An OLED light-emitting layer is formed on the array substrate in the plane area; the OLED light-emitting layer is electrically connected to the driving unit in the plane area;

[0039] A first encapsulation layer is formed on a side of the OLED light-emitting layer away from the array substrate; the bending stress of the first encapsulation layer is greater than the bending stress of the second encapsulation layer;

[0040] forming a polarizing layer on a side of the first packaging layer away from the array substrate;

[0041] A cover plate is formed on a side of the polarizing layer and the second encapsulation layer away from the array substrate.

[0042] The method for preparing the display panel provided in this embodiment adopts an OLED light-emitting layer in the flat area of ​​the display panel, while a Micro LED light-emitting layer is adopted in the bending area of ​​the display panel. When bent, the display panel made of Micro LED can be subjected to lower bending stress than the display panel made of OLED. The use of the Micro LED light-emitting layer in the bending area and the OLED light-emitting layer in the flat area can make the bending stress of the display panel in the bending area smaller than the bending stress of the display panel in the flat area, thereby improving the folding resistance of the display panel to ensure the display effect of the display panel and the display device. In addition, the OLED light-emitting layer is adopted in the flat area, and the Micro LED light-emitting layer is adopted only in a small area of ​​the bending area. There is no need to transfer Micro LED over a large area, which can get rid of the dilemma of low yield of large-scale transfer.

[0043] A third aspect of the embodiments of the present application provides a display device, comprising the display panel of the first aspect.

[0044] The display device provided in this embodiment includes a display panel, wherein the flat area of ​​the display panel adopts an OLED light-emitting layer, while the bending area of ​​the display panel adopts a Micro LED light-emitting layer. When bent, the display panel made of Micro LED can be subjected to lower bending stress than the display panel made of OLED. The use of the Micro LED light-emitting layer in the bending area and the OLED light-emitting layer in the flat area can make the bending stress of the display panel in the bending area smaller than the bending stress of the display panel in the flat area, thereby improving the folding resistance of the display panel to ensure the display effect of the display panel and the display device. In addition, the OLED light-emitting layer is used in the flat area, and the Micro LED light-emitting layer is used only in a small area of ​​the bending area. There is no need to transfer Micro LEDs over a large area, which can get rid of the dilemma of low yield of large-scale transfer.

[0045] The structure of the present application and its other inventive objectives and beneficial effects will be more clearly understood through the description of the preferred embodiments in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. It is obvious that the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0047] Figure 1 Schematic diagram of the structure of each functional film layer in the display panel in the bending area when bent;

[0048] Figure 2A top view of a light-emitting layer in a display panel provided in an embodiment of the present application;

[0049] Figure 3 A cross-sectional view of a display panel provided in an embodiment of the present application;

[0050] Figure 3a A cross-sectional view of a display panel provided in an embodiment of the present application without a second encapsulation layer;

[0051] Figure 4 A schematic structural diagram of an array substrate provided in an embodiment of the present application;

[0052] Figure 4a A schematic structural diagram of another array substrate provided in an embodiment of the present application;

[0053] Figure 5 A schematic diagram of the structure of the Micro LED light-emitting layer provided in an embodiment of the present application;

[0054] Figure 6 A schematic structural diagram of a cover plate provided in an embodiment of the present application;

[0055] Figure 7 A schematic structural diagram of another cover plate provided in an embodiment of the present application;

[0056] Figure 8 A schematic diagram of another cover structure provided in an embodiment of the present application;

[0057] Figure 9 A flow chart of a method for manufacturing a display panel provided in an embodiment of the present application;

[0058] Figure 10 This is a schematic structural diagram of the display panel after step S10 is completed in the method for manufacturing the display panel provided in an embodiment of the present application;

[0059] Figure 11 This is a schematic structural diagram of the display panel after step S20 is completed in the method for manufacturing the display panel provided in an embodiment of the present application;

[0060] Figure 12 This is a schematic structural diagram of the display panel after step S30 is completed in the method for manufacturing the display panel provided in an embodiment of the present application;

[0061] Figure 13 This is a schematic structural diagram after completing step S40 in the method for manufacturing a display panel provided in an embodiment of the present application;

[0062] Figure 14 This is a schematic structural diagram after completing step S50 in the method for manufacturing a display panel provided in an embodiment of the present application.

[0063] Description of reference numerals:

[0064] 100-display panel; 100a-bending area; 100b-flat area;

[0065] 11-intima layer; 12-neutral membrane layer; 13-outer membrane layer;

[0066] 20-array substrate; 21-substrate; 22-thin film transistor;

[0067] 221 - gate signal line; 231 - first electrode connection line; 232 - second electrode connection line;

[0068] 241-light signal line; 242-common line; 25-capacitor structure;

[0069] 26-insulating layer; 27-planarization layer; 30-light-emitting layer;

[0070] 31-pixel defining layer; 311-pixel opening; 312-connection hole;

[0071] 32-OLED light-emitting layer; 321-organic light-emitting unit; 322-anode layer;

[0072] 323-luminescent material layer; 324-cathode layer; 33-Micro LED luminescent layer;

[0073] 331-LED die; 40-encapsulation layer; 41-first encapsulation layer;

[0074] 42-second encapsulation layer; 421-first organic layer; 422-second organic layer;

[0075] 423 - intermediate insulating layer; 50 - cover plate; 51 - first cover plate portion;

[0076] 52-second cover portion; 60-polarizing layer; 70-light-transmitting filling layer. DETAILED DESCRIPTION

[0077] In related technologies, an organic light-emitting diode (OLED) display panel includes a bending region and two planar regions, and the two planar regions are connected by the bending region. When the display panel is folded, the two planar regions move toward each other and remain in a planar state, while the bending region is bent. Figure 1As shown, when the bending zone is bent, the various functional film layers in the display panel located in the bending zone will be subjected to bending stress. For example, the functional film layers in the bending zone may include an inner film layer 11, a neutral film layer 12, and an outer film layer 13. The inner film layer 11 refers to the functional film layer located on the inner side of the bend during bending, and the outer film layer 13 refers to the functional film layer located on the outer side of the bend during bending. The neutral film layer 12 is located between the inner film layer 11 and the outer film layer 13. During bending, the inner film layer 11 is subjected to a compressive stress F1, and the outer film layer 13 is subjected to a tensile stress F2. The compressive and tensile stresses on the neutral film layer 12 offset each other, and the neutral film layer 12 is not subjected to any stress.

[0078] However, since the bending radius of the bending zone is small and the OLED panel is thick, when the display panel in the bending zone is bent, the outer film layer 13 is subjected to a large tensile stress and the inner film layer 11 is subjected to a large compressive stress. The functional film layers are easily peeled off, causing the functional film layers to fail, which affects the display effect of the display panel and the display device.

[0079] During the research process, the applicant found that the difference between Micro Light Emitting Diode (Micro LED or μLED) and OLED lies in the material composition of the LED part. OLED uses organic materials to form light-emitting units in the light-emitting layer. Organic materials are more sensitive to water and oxygen, and there are more inorganic film layers in its encapsulation layer to ensure the isolation performance against water and oxygen. Micro LED uses inorganic materials to form light-emitting units, which can reduce the requirements for the encapsulation layer. The encapsulation layer of Micro LED can be mainly encapsulated with an organic encapsulation film layer. The organic encapsulation film layer is relatively soft and can alleviate the bending stress of the Micro LED display panel, so that the bending stress of the Micro LED display panel is less than that of the OLED display panel.

[0080] However, the biggest challenge in Micro LED production lies in how to place a massive number of micron-sized LED chips onto a target substrate or circuit board using high-precision equipment. This process is called mass transfer. Mass transfer technology has low yield rates and requires extremely high soldering precision, making it difficult to commercialize on a large scale.

[0081] Based on the above problems, this embodiment provides a display panel, a method for preparing a display panel, and a display device. The flat area of ​​the display panel adopts an OLED light-emitting layer, while the bending area of ​​the display panel adopts a Micro LED light-emitting layer. When bent, the display panel made of Micro LED can be subjected to lower bending stress than the display panel made of OLED. Using a Micro LED light-emitting layer in the bending area and an OLED light-emitting layer in the flat area can make the bending stress of the display panel in the bending area smaller than the bending stress of the display panel in the flat area, thereby improving the folding resistance of the display panel to ensure the display effect of the display panel and the display device. In addition, the OLED light-emitting layer is used in the flat area, and the Micro LED light-emitting layer is used only in a small area of ​​the bending area. There is no need to transfer Micro LED over a large area, which can get rid of the dilemma of low yield of mass transfer.

[0082] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0083] This embodiment provides a display device including a display panel 100. The display device may be a mobile or fixed terminal having the display panel 100, such as an electronic paper, a mobile phone, a tablet computer, a television, a monitor, a notebook computer, a digital photo frame, a super personal computer, or a navigator.

[0084] The display panel 100 provided in the embodiment of the present application will be described in detail below with reference to the accompanying drawings.

[0085] like Figure 2 and Figure 3 As shown, this embodiment provides a display panel 100, which can be applied to a display device. The display panel 100 includes a bending region 100a and at least two planar regions 100b, where two adjacent planar regions 100b are connected by the bending region 100a.

[0086] In some examples, the display panel 100 includes a bending region 100a and two planar regions 100b, with the two planar regions 100b connected by the bending region 100a. In this way, the display panel 100 can be folded in half. In other examples, the display panel 100 includes more than two planar regions 100b, with two adjacent planar regions 100b connected by a bending region 100a. In this way, the display panel 100 can be folded multiple times, resulting in a smaller area after folding. This embodiment does not limit the number of planar regions 100b and bending regions 100a to provide users with more options.

[0087] This application provides a detailed description by taking an example where the display panel 100 includes a bending area 100 a and two planar areas 100 b .

[0088] It should be noted that the state of the display panel 100 may include a flat state and a folded state. The flat state and the folded state of the display panel 100 are also the flat state and the folded state of the display device.

[0089] like Figure 2 As shown, the flattened state refers to a state in which all parts of the display panel 100 are roughly in the same plane. In this state, the two flat areas 100b and the bent area 100a are roughly in the same plane, and the angle between two adjacent flat areas 100b is approximately 180 degrees. In the flattened state, the display panel 100 has a larger display area, ensuring a better user experience.

[0090] The folded state refers to the display panel 100 having its bending region 100a bent. The two ends of the bending region 100a, where they connect to the two flat regions 100b, are folded and overlap in the thickness direction of the display panel 100. In this state, the two flat regions 100b overlap in the thickness direction of the display panel 100, and the angle between the two flat regions 100b is approximately 0 degrees. In the folded state, the display panel 100, and the display device incorporating the display panel 100, are compact, making the display device easier to store and carry.

[0091] It is understandable that when a user is using the display device, the display panel 100 may be in a folded state, a flattened state, or any state therebetween, and this embodiment does not impose any limitation thereto.

[0092] like Figure 3 As shown, the display panel 100 includes an array substrate 20 and a light-emitting layer 30 located on the array substrate 20. A plurality of driving units (not shown) are provided in the array substrate 20. The plurality of driving units are arranged in an array and electrically connected to the light-emitting layer 30. The driving units are used to provide driving current to the light-emitting layer 30.

[0093] The light-emitting layer 30 includes an OLED light-emitting layer 32 and a Micro LED light-emitting layer 33 . The OLED light-emitting layer 32 is distributed on the array substrate 20 located in the planar area 100 b , and the Micro LED light-emitting layer 33 is distributed on the array substrate 20 located in the bending area 100 a .

[0094] This is equivalent to using a Micro LED display panel in the bending area 100a and an OLED display panel in the flat area 100b. When bending, the display panel made of Micro LED is subject to lower bending stress than the display panel made of OLED. Using a Micro LED light-emitting layer 33 in the bending area 100a and an OLED light-emitting layer 32 in the flat area 100b can make the bending stress of the display panel in the bending area 100a smaller than the bending stress of the display panel in the flat area 100b, thereby reducing the stress on each functional film layer in the display panel 100 in the bending area 100a and improving the folding resistance of the display panel 100 to ensure the display effect of the display panel 100 and the display device. In addition, the flat area 100b uses the OLED light-emitting layer 32, and the Micro LED light-emitting layer 33 is only used in a small area in the bending area 100a. There is no need to transfer Micro LEDs over a large area, which can get rid of the dilemma of low yield of large-scale transfer.

[0095] Continue as Figure 3 As shown, the display panel 100 may further include an encapsulation layer 40 , which covers the OLED light-emitting layer 32 and the Micro LED light-emitting layer 33 . The encapsulation layer 40 is used to block water and oxygen and protect the light-emitting layer 30 .

[0096] The encapsulation layer 40 may include a first encapsulation layer 41, which is located on a side of the OLED light-emitting layer 32 away from the array substrate 20. The first encapsulation layer 41 is used to protect the OLED light-emitting layer 32. The first encapsulation layer 41 may use thin film encapsulation (TFE) technology to encapsulate the OLED light-emitting layer 32. The TFE may have an inorganic layer / organic layer / inorganic layer structure. The inorganic layer effectively blocks water and oxygen, while the organic layer buffers stress within the inorganic layer to enhance the flexibility of the OLED display panel.

[0097] In addition, the encapsulation layer 40 may include a second encapsulation layer 42, which is located on a side of the Micro LED light-emitting layer 33 away from the array substrate 20. The second encapsulation layer 42 is used to protect the Micro LED light-emitting layer 33. Compared to the OLED light-emitting layer 32, which uses organic materials to form the light-emitting units, the Micro LED light-emitting layer 33 uses inorganic materials to form the light-emitting units, thereby reducing the encapsulation requirements for the second encapsulation layer 42 to block water and oxygen. The second encapsulation layer 42 can be primarily formed of an organic layer with greater elasticity. Therefore, the second encapsulation layer 42 can buffer the bending stress experienced by the Micro LED light-emitting layer 33, thereby reducing the bending stress of the display panel 100 in the bending region 100a, improving the folding resistance of the display panel 100, and ensuring the display effect of the display panel 100 and the display device.

[0098] In some embodiments, due to lower requirements for the water and oxygen barrier performance of the second encapsulation layer 42, the second encapsulation layer 42 can be made thinner, with fewer film layers. This thickness is equivalent to the sum of the thicknesses of the first encapsulation layer 41 and the OLED light-emitting layer 32, and is greater than the sum of the thicknesses of the second encapsulation layer 42 and the Micro LED light-emitting layer 33. This reduces the combined thickness of the second encapsulation layer 42 and the Micro LED light-emitting layer 33, reducing the bending stress of the display panel 100 in the bending region 100a and improving the folding resistance of the display panel 100, thereby ensuring the display quality of the display panel 100 and the display device.

[0099] It should be noted that the sum of the thicknesses of the first encapsulation layer 41 and the OLED light-emitting layer 32 can also be less than or equal to the sum of the thicknesses of the second encapsulation layer 42 and the Micro LED light-emitting layer 33. Because the second encapsulation layer 42 is primarily formed of organic materials, it can buffer the bending stress experienced by the Micro LED light-emitting layer 33. Therefore, the total bending stress of the Micro LED light-emitting layer 33 and the second encapsulation layer 42 is relatively low.

[0100] In some embodiments, such as Figure 3a As shown, the second encapsulation layer 42 may not be provided on the side of the Micro LED light-emitting layer 33 away from the array substrate 20, that is, the Micro LED light-emitting layer 33 does not need to be encapsulated. The first encapsulation layer 41 is provided only on the side of the OLED light-emitting layer 32 away from the array substrate 20. This can reduce the thickness of the display panel in the bending region 100a, thereby reducing the bending stress of the display panel 100 in the bending region 100a, improving the folding resistance of the display panel 100, and ensuring the display effect of the display panel 100 and the display device.

[0101] In some embodiments, combined Figure 2As shown, the distribution density of the light-emitting units in the Micro LED light-emitting layer 33 is less than the distribution density of the light-emitting units in the OLED light-emitting layer 32. The light-emitting units in the Micro LED light-emitting layer 33 are Micro LED light-emitting units, namely, LED crystals 331. The light-emitting units in the OLED light-emitting layer 32 are OLED light-emitting units, namely, organic light-emitting units 321. The distribution density of LED crystals 331 is less than the distribution density of organic light-emitting units 321. In this way, the number of LED crystals 331 and driving units in the bending area 100a is relatively small, which can reduce the stress on the display panel 100 in the bending area 100a when it is bent. Here, "distribution density" refers to the number of light-emitting units in the display panel per unit area.

[0102] In this embodiment, Figure 3 As shown, the display panel 100 may further include a cover plate 50 . The cover plate 50 is located on a side of the first encapsulation layer 41 and the second encapsulation layer 42 away from the array substrate 20 . The cover plate 50 protects the display panel 100 .

[0103] like Figure 3 As shown, the light emitting layer 30 further includes a pixel defining layer 31. The light emitting layers 30 in the bending area 100a and the planar area 100b can share not only the array substrate 20 but also the pixel defining layer 31. In this way, the manufacturing process is relatively simple.

[0104] like Figure 3 As shown, both the OLED light-emitting layer 32 and the Micro LED light-emitting layer 33 include multiple light-emitting units, and the light-emitting unit in the OLED light-emitting layer 32 is an organic light-emitting unit 321.

[0105] The organic light-emitting unit 321 includes an anode layer 322, a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting material layer 323, a hole blocking layer, an electron transport layer, an electron injection layer and a cathode layer 324, which are stacked in sequence. The embodiment of the present application does not limit this. Figure 4 and Figure 4a Only the anode layer 322, the light emitting material layer 323 and the cathode layer 324 are shown. The pixel defining layer 31 in the plane area 100b has a plurality of pixel openings 311, and the light emitting material layer 323 and at least part of the cathode layer 324 are located in the pixel openings 311. Figure 4 and Figure 4a The anode layer 322 of the OLED light-emitting layer 32 is located between the array substrate 20 and the pixel defining layer 31 , and the cathode layer 324 covers the side of the pixel defining layer 31 away from the array substrate 20 .

[0106] like Figure 4As shown, the array substrate 20 may include a substrate 21 and multiple driving units located on the substrate 21. The driving units include thin film transistors 22 (TFTs) and capacitor structures 25. The driving units are used to generate a driving current to drive the light-emitting layer 30 to emit light. The multiple driving units are arranged in an array, wherein one driving unit is electrically connected to and drives one light-emitting unit.

[0107] For example, the thin film transistor 22 may be a low temperature polycrystalline silicon (LTPS) thin film transistor or a low temperature polycrystalline oxide (LTPO) thin film transistor, which is not limited in the embodiment of the present application.

[0108] Specifically, substrate 21 can be made of a transparent material such as polyimide (PI), a condensation polymer of phthalic acid and ethylene glycol (PET), or other highly elastic materials to reduce the rigidity of substrate 21 and minimize stress on substrate 21 during bending. Substrate 21 can also provide support for the remaining structural layers subsequently arranged.

[0109] The light-emitting units in the Micro LED light-emitting layer 33 are micron-sized LED chips 331, which are located on the side of the array substrate 20 facing away from the substrate 21. The LED chips 331 include a first electrode and a second electrode. The first electrode can be the anode of the LED chip 331, and the second electrode can be the cathode of the LED chip 331.

[0110] like Figure 4 and Figure 5As shown, in the bending region 100a, the driving unit includes a first polarity connection line 231, a second polarity connection line 232, a light-emitting signal line 241, and a common line 242. The light-emitting signal line 241 and the common line 242 are arranged between the array substrate 20 and the pixel-defining layer 31. The driving unit provides a driving current to the LED die 331 through the light-emitting signal line 241. A connection hole 312 is provided in the pixel-defining layer 31. The opening of one end of the connection hole 312 is located on the side of the pixel-defining layer 31 facing away from the substrate 21, and the opening of the other end of the connection hole 312 is located on the side of the pixel-defining layer 31 facing the substrate 21. The connection hole 312 penetrates the pixel-defining layer 31 along the thickness direction of the pixel-defining layer 31. Part of the luminous signal line 241 and the common line 242 is exposed at the connection hole 312 , so that the luminous signal line 241 is connected to the first pole of the LED chip 331 through the first pole connection line 231 , and the common line 242 is connected to the second pole of the LED chip 331 through the second pole connection line 232 .

[0111] Specifically, the first-pole connecting wire 231 and the second-pole connecting wire 232 are located in different connecting holes 312. The first end of the first-pole connecting wire 231 is connected to the light-emitting signal wire 241, and the second end of the first-pole connecting wire 231 is connected to the first pole of the LED die 331. The first end of the second-pole connecting wire 232 is connected to the common line 242, and the second end of the second-pole connecting wire 232 is connected to the second pole of the LED die 331. The first end of the connecting wire is the end close to the array substrate 20, and the second end of the connecting wire is the end away from the array substrate 20.

[0112] Continue as Figure 3 As shown, the display panel 100 may further include a polarizing layer 60, which is located between the cover plate 50 and the first encapsulation layer 41. Because the cathode layer 324 in the OLED light-emitting layer 32 reflects light, ambient light that strikes the cathode layer 324 will be reflected by the cathode layer 324, affecting the display quality of the display panel 100. Covering the polarizing layer 60 on the side of the OLED light-emitting layer 32 facing away from the substrate 21 prevents ambient light from being emitted through reflection, thereby preventing the reflected light from affecting the display quality of the display panel 100.

[0113] Because the luminous signal lines 241 and the common lines 242 are covered by the pixel defining layer 31, which can be formed of a light-absorbing material, the pixel defining layer 31 can absorb incident ambient light, thereby preventing the ambient light from irradiating the luminous signal lines 241 and the common lines 242 covered by the pixel defining layer 31. This prevents the luminous signal lines 241 and the common lines 242 from reflecting the ambient light, thereby preventing the reflection of the ambient light from affecting the display effect of the display panel 100. In this way, the display panel 100 in the bending region 100a does not need to be provided with a polarizing layer 60, and the thickness of the display panel 100 in the bending region 100a is reduced, thereby reducing the bending stress of the display panel 100 in the bending region 100a and improving the folding resistance of the display panel 100.

[0114] In addition, due to the high luminous efficiency and brightness of Micro LED, the aperture ratio of the Micro LED light-emitting layer 33 can be smaller than the aperture ratio of the OLED light-emitting layer 32. The various metal traces exposed in the opening area of ​​the Micro LED light-emitting layer 33 will be fewer, and the area of ​​the non-opening area of ​​the Micro LED light-emitting layer 33 will be larger. The non-opening area can be covered with a light-absorbing material layer. Therefore, the Micro LED light-emitting layer 33 reflects less light, and there is no need to set a polarizer 60.

[0115] like Figure 2 and Figure 5 As shown, a plurality of LED dies 331 are arrayed on the array substrate 20, and the second encapsulation layer 42 may include a first organic layer 421, which is located between adjacent LED dies 331 to insulate adjacent LED dies 331. In addition, the first organic layer 421 is also located between adjacent first pole connecting lines 231 and second pole connecting lines 232 to insulate adjacent first pole connecting lines 231 and second pole connecting lines 232. The first organic layer 421 may be formed of a relatively soft elastic material, thereby buffering the bending stress of the display panel 100 in the bending area 100a. For example, the first organic layer 421 may be formed of an elastic light-absorbing material (such as a black resin), thereby buffering the bending stress while preventing color cross-talk between adjacent LED dies 331.

[0116] The second encapsulation layer 42 may further include a second organic layer 422, which is located on a side of the first organic layer 421 facing away from the array substrate 20. The second organic layer 422 is arranged opposite to the area between two adjacent LED dies 331. The second organic layer 422 may be formed of a relatively soft elastic material, thereby buffering the bending stress exerted on the display panel 100 in the bending area 100a. For example, the second organic layer 422 may be formed of an elastic light-absorbing material (such as a black resin), thereby buffering the bending stress while further avoiding the problem of color crosstalk between adjacent LED dies 331. The materials of the first organic layer 421 and the second organic layer 422 may be the same or different.

[0117] The second encapsulation layer 42 may further include an intermediate insulating layer 423, which may be located between the first organic layer 421 and the second organic layer 422. The intermediate insulating layer 423 may be formed of a light-transmitting material, allowing light from the LED die 331 to pass through the intermediate insulating layer 423 and emit light normally. In some examples, the second organic layer 422 may be embedded in the intermediate insulating layer 423, with the surface of the second organic layer 422 facing away from the array substrate 20 flush with the surface of the intermediate insulating layer 423 facing away from the array substrate 20. In this way, the total thickness of the second organic layer 422 and the intermediate insulating layer 423 may be set to be thinner. The intermediate insulating layer 423 may be made of an inorganic material, such as silicon nitride, and may be relatively thin to reduce the bending stress of the second encapsulation layer 42.

[0118] In some embodiments, such as Figure 3 As shown, the display panel 100 may further include a light-transmitting filling layer 70, which is located between the cover plate 50 and the second encapsulation layer 42. The light-transmitting filling layer 70 may be formed of an elastic material and may be relatively soft to buffer the bending stress of the display panel 100 in the bending region 100a. For example, the light-transmitting filling layer 70 may be formed of a transparent organic adhesive.

[0119] In some embodiments, such as Figure 3 、 Figure 6 and Figure 7 As shown, the surface of the cover plate 50 in the bending area 100a away from the array substrate 20 is flush with the surface of the cover plate 50 in the flat area 100b away from the array substrate 20. In this way, the surface flatness of the display panel 100 is better, and the display effect is better.

[0120] The cover plate 50 may include a first cover plate portion 51 and a second cover plate portion 52 connected to each other. The cover plate 50 located in the flat area 100 b is the first cover plate portion 51 , and the cover plate 50 located in the bending area 100 a is the second cover plate portion 50 .

[0121] Some examples, such as Figure 3 As shown, the thickness of the first cover portion 51 is equal to the thickness of the second cover portion 52 , and a light-transmitting filling layer 70 is provided between the second cover portion 52 and the second encapsulation layer 42 , and the light-transmitting filling layer 70 supports the second cover portion 52 .

[0122] In other examples, such as Figure 6 and Figure 7 As shown, the thickness of the first cover portion 51 is less than that of the second cover portion 52, and the second cover portion 52 extends between the polarizing layers 60 of two adjacent plane areas 100b to fill the space between the second cover portion 52 and the second encapsulation layer 42. Figure 6 As shown, the side of the second cover portion 52 facing the array substrate 20 can be bonded to the second packaging layer 42. At this time, there is no need to set a transparent filling layer 70. There are fewer film layers between the second cover portion 52 and the second packaging layer 42, and the preparation process is relatively simple.

[0123] like Figure 7 As shown, a light-transmitting filling layer 70 may also be provided between the second cover portion 52 and the second encapsulation layer 42, and the surface of the second cover portion 52 facing the array substrate 20 is in contact with the light-transmitting filling layer 70. In this way, the thickness of the light-transmitting filling layer 70 and the second cover portion 52 can be adjusted to meet the different bending stress requirements of the bending area 100a.

[0124] In some embodiments, such as Figure 8 As shown, the surface of the cover plate 50 located in the bend region 100a, away from the array substrate 20, is lower than the surface of the cover plate 50 located in the flat region 100b, away from the array substrate 20. Specifically, by bending the cover plate 50 in the bend region 100a toward the array substrate 20, the surface of the cover plate 50 located in the bend region 100a, closer to the array substrate 20, can be brought into contact with the second encapsulation layer 42. This makes the display panel 100 in the bend region 100a thinner overall, resulting in less bending stress. The uniform thickness of the cover plate 50 simplifies its manufacturing process.

[0125] In addition, Micro LED inherits the high efficiency and high brightness characteristics of inorganic LEDs. Under the same brightness, Micro LED requires less driving current than OLED, and the arrangement density of metal traces in its driving unit is lower than that of OLED, which can reduce the rigidity of the display panel.

[0126] For example, the planar region 100b may employ a 7T1C drive unit (T represents a TFT, and C represents a capacitor structure), while the bending region 100a may employ a 2T1C or 3T1C drive unit. The arrangement density of the metal traces within the drive unit in the bending region 100a is lower than the arrangement density of the metal traces within the drive unit in the planar region 100b. This can reduce the bending stress experienced by the array substrate 20 in the bending region 100a during bending, thereby reducing the stress experienced by the display panel 100 in the bending region 100a during bending.

[0127] In some examples, the thin film transistor 22 in the driving unit may include a gate signal line 221, a source electrode, and a drain electrode. The width-to-length ratio of the gate signal line 221 of the driving unit located in the planar region 100b is greater than the width-to-length ratio of the gate signal line 221 of the driving unit located in the bending region 100a. The smaller the required driving current, the smaller the width-to-length ratio of the gate signal line 221. In other words, the gate signal line 221 in the bending region 100a can be set to be smaller to reduce the wiring area of ​​the gate signal line 221 in the bending region 100a, thereby reducing the bending stress of the display panel 100 in the bending region 100a.

[0128] The following is a detailed description of a method for manufacturing the display panel 100 provided in an embodiment of the present application.

[0129] like Figure 9 As shown, the manufacturing method of the display panel 100 provided in the present application may include:

[0130] S10: providing an array substrate; the array substrate comprises a substrate and a plurality of driving units disposed on the substrate, wherein the plurality of driving units are arranged in an array.

[0131] like Figure 10 As shown, an array substrate 20 is provided. The array substrate 20 refers to a substrate on which a driving unit is formed. The driving unit may include a thin film transistor 22 and a capacitor structure 25. The driving unit is used to drive the light-emitting layer 30 in the display panel 100 to emit light. The array substrate 20 includes a substrate 21, on which the driving unit is disposed. The substrate 21 is used to support the driving unit.

[0132] The driving unit can be formed by two or more thin-film transistors 22 and one or more capacitor structures 25. For example, the driving unit in the planar region 100b has a 7T1C structure, while the driving unit in the bending region 100a has a 2T1C or 3T1C structure. In this way, the arrangement density of the metal traces of the driving unit in the bending region 100a is lower than that of the driving unit in the planar region 100b, thereby reducing the bending stress experienced by the array substrate 20 in the bending region 100a when bending.

[0133] In some examples, the metal trace density of the drive unit can be adjusted by adjusting the width-to-length ratio of the gate signal line 221 of the thin-film transistor 22 in the drive unit. For example, the width-to-length ratio of the gate signal line 221 of the thin-film transistor 22 in the bending region 100a is smaller than the width-to-length ratio of the gate signal line 221 of the thin-film transistor 22 in the planar region 100b.

[0134] The thin film transistor 22 may include a gate signal line 221 , a source electrode, a drain electrode, and an active layer connected to the source / drain electrodes.

[0135] like Figure 4 As shown, the array substrate 20 further includes multiple insulating layers 26 and a planarization layer 27 stacked sequentially on the substrate 21. Each metal trace of the thin-film transistor 22 is covered with an insulating layer 26, which serves to electrically insulate the metal traces of different layers. The planarization layer 27 is used to flatten the array substrate 20 and reduce display defects. The structural film layers below the planarization layer 27 can be shared between the bending region 100a and the flat region 100b, simplifying the manufacturing process.

[0136] S20: forming a Micro LED light-emitting layer on the array substrate in the bending region, and forming a second encapsulation layer on a side of the Micro LED light-emitting layer away from the array substrate; the Micro LED light-emitting layer is electrically connected to the driving unit in the bending region.

[0137] like Figure 11 As shown, the Micro LED light-emitting layer 33 includes multiple LED dies 331. The LED dies 331 can be first prepared on a semiconductor substrate and then transferred to the array substrate 20 in the bending region 100a using a transfer technique. The LED dies 331 are welded to the driving units in the bending region 100a in a one-to-one correspondence.

[0138] The Micro LED light emitting layer 33 in the bending region 100a is then encapsulated. Since the LED die 331 is made of inorganic material, the second encapsulation layer 42 can be made thinner and simpler, thereby reducing the bending stress of the display panel 100 in the bending region 100a.

[0139] S30: forming an OLED light-emitting layer on the array substrate in the planar area; and electrically connecting the OLED light-emitting layer to the driving unit in the planar area.

[0140] like Figure 12As shown, after the Micro LED light-emitting layer 33 is encapsulated, the planar area 100b is evaporated to form the OLED light-emitting layer 32. The OLED light-emitting layer 32 includes a plurality of organic light-emitting units 321, which are electrically connected to the driving units in the planar area 100b in a one-to-one correspondence.

[0141] like Figure 4 As shown, the OLED light-emitting layer 32 includes an anode layer 322 located between the planarization layer 27 and the pixel-defining layer 31, and a light-emitting material layer 323 and a cathode layer 324 stacked in sequence on the anode layer 322. The cathode layer 324 is located above the organic light-emitting unit 321 and covers the pixel-defining layer 31. The anode layer 322 contacts the source / drain of the driving unit through contact holes penetrating the planarization layer 27 to achieve electrical connection.

[0142] S40: forming a first encapsulation layer on a side of the OLED light-emitting layer away from the array substrate; the bending stress of the first encapsulation layer is greater than the bending stress of the second encapsulation layer.

[0143] like Figure 13 As shown, after forming the cathode layer 324, a first encapsulation layer 41 can be formed to cover the cathode layer 324. The first encapsulation layer 41 is located in the planar region 100b. Specifically, the first encapsulation layer 41 can be a thin film encapsulation layer. The thickness of the second encapsulation layer 42 is less than that of the first encapsulation layer 41. In addition, the second encapsulation layer 42 can be primarily composed of an organic layer. This reduces the bending stress of the display panel 100 in the bending region 100a.

[0144] S50: forming a polarizing layer on a side of the first encapsulation layer away from the array substrate.

[0145] like Figure 14 As shown, the polarizing layer 60 is provided in the planar area 100 b but not in the bending area 100 a , so that the thickness of the display panel 100 in the bending area 100 a can be reduced.

[0146] S60: forming a cover plate on a side of the first encapsulation layer and the second encapsulation layer away from the array substrate.

[0147] like Figure 8 As shown, a cover plate 50 is formed on the side of the first encapsulation layer 41 and the second encapsulation layer 42 away from the array substrate 20. Before the bending region 100a is covered with the cover plate 50, a light-transmitting filling layer 70 can be formed on the side of the second encapsulation layer 42 away from the array substrate 20, and then the cover plate 50 in the bending region 100a is covered on the side of the light-transmitting filling layer 70 away from the array substrate 20.

[0148] Of course, the cover plate 50 of the bending area 100 a may also be directly disposed on the surface of the second packaging layer 42 facing away from the array substrate 20 .

[0149] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A display panel, characterized in that: The display panel comprises a bending region and at least two planar regions, wherein two adjacent planar regions are connected by the bending region, and the display panel comprises an array substrate, an OLED light-emitting layer, and a Micro LED light-emitting layer; The OLED light-emitting layer is distributed on the array substrate located in the planar area, and the Micro LED light-emitting layer is distributed on the array substrate located in the bending area; The bending stress of the display panel located in the bending area is smaller than the bending stress of the display panel located in the flat area; Also included is an encapsulation layer, the encapsulation layer including a first encapsulation layer and a second encapsulation layer; It also includes a cover plate and a polarizing layer, wherein the cover plate is located on a side of the first encapsulation layer and the second encapsulation layer away from the array substrate; the polarizing layer is located between the cover plate and the first encapsulation layer; It also includes a light-transmitting filling layer, the light-transmitting filling layer is located between the cover plate and the second encapsulation layer, and the thickness of the second encapsulation layer is less than the thickness of the first encapsulation layer; The cover plate includes a first cover plate portion and a second cover plate portion connected to each other, the thickness of the first cover plate portion is not greater than the thickness of the second cover plate portion, and the surfaces of the first cover plate portion and the second cover plate portion on a side away from the array substrate are flush; The first cover portion is located on a side of the first packaging layer away from the array substrate, and the second cover portion is located on a side of the second packaging layer away from the array substrate.

2. The display panel according to claim 1, wherein: The first encapsulation layer is located on a side of the OLED light-emitting layer away from the array substrate, and the second encapsulation layer is located on a side of the Micro LED light-emitting layer away from the array substrate; The bending stress of the second packaging layer is smaller than the bending stress of the first packaging layer.

3. The display panel according to claim 2, wherein: The Micro LED light-emitting layer includes a plurality of Micro LED light-emitting units arranged in an array, and the OLED light-emitting layer includes a plurality of OLED light-emitting units arranged in an array. The distribution density of the Micro LED light-emitting units in the Micro LED light-emitting layer is less than the distribution density of the OLED light-emitting units in the OLED light-emitting layer.

4. The display panel according to claim 3, wherein: The sum of the thicknesses of the first encapsulation layer and the OLED light-emitting layer is greater than the sum of the thicknesses of the second encapsulation layer and the Micro LED light-emitting layer.

5. The display panel according to claim 2 or 3, wherein: The overall thickness of the cover plate is uniform, and the surface of the cover plate located in the bending area close to the array substrate is in contact with the second packaging layer; The surface of the cover plate located in the bending area and away from the array substrate is lower than the surface of the cover plate located in the flat area and away from the array substrate.

6. The display panel according to any one of claims 1 to 3, characterized in that: The array substrate includes a substrate and a plurality of driving units disposed on the substrate, wherein the plurality of driving units are arranged in an array; The arrangement density of the metal wiring in the driving unit located in the planar area is greater than the arrangement density of the metal wiring in the driving unit located in the bending area.

7. The display panel according to claim 6, wherein: The width-to-length ratio of the gate signal line of the driving unit located in the planar area is greater than the width-to-length ratio of the gate signal line of the driving unit located in the bending area.

8. The display panel according to claim 7, wherein: The driving unit located in the bending area includes a first pole connecting line, a second pole connecting line, a light-emitting signal line and a common line. The first end of the first pole connecting line is connected to the light-emitting signal line, the second end of the first pole connecting line is connected to the first pole of the Micro LED light-emitting layer, the first end of the second pole connecting line is connected to the common line, and the second end of the second pole connecting line is connected to the second pole of the Micro LED light-emitting layer.

9. A method for preparing a display panel, characterized in that: The display panel includes a bending area and at least two planar areas, and two adjacent planar areas are connected by the bending area; The method for preparing the display panel includes: An array substrate is provided; the array substrate comprises a substrate and a plurality of driving units disposed on the substrate, wherein the plurality of driving units are arranged in an array; forming a Micro LED light-emitting layer on the array substrate in the bending region, and forming a second encapsulation layer on a side of the Micro LED light-emitting layer away from the array substrate; the Micro LED light-emitting layer is electrically connected to the driving unit in the bending region; forming an OLED light-emitting layer on the array substrate in the plane area; the OLED light-emitting layer is electrically connected to the driving unit in the plane area; A first encapsulation layer is formed on a side of the OLED light-emitting layer away from the array substrate; the bending stress of the first encapsulation layer is greater than the bending stress of the second encapsulation layer; forming a polarizing layer on a side of the first encapsulation layer away from the array substrate; A cover plate is formed on a side of the polarizing layer and the second encapsulation layer away from the array substrate.

10. A display device, characterized in that: The display panel comprises any one of claims 1 to 8.

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