Flexible display panel, preparation method thereof, and display device

Abstract

The present invention provides a flexible display panel, a preparation method thereof, and a display device. The flexible display panel includes: a flexible substrate; a display functional layer disposed on one side of the flexible substrate; and a flexible encapsulation layer disposed on the side of the display functional layer away from the flexible substrate. Among them, the flexible encapsulation layer includes a reinforcement encapsulation layer and a base encapsulation layer. The reinforcement encapsulation layer is disposed between the base encapsulation layer and the display functional layer, and the reinforcement encapsulation layer includes a strength reinforcement material. By adding a reinforcement encapsulation layer including a strength reinforcement material between the base encapsulation layer and the display functional layer, and utilizing the high-strength characteristics of the strength reinforcement material, while not affecting the light extraction of the display panel, the strength of the flexible encapsulation layer is enhanced, realizing a flexible display panel with high-strength encapsulation and reducing the risk of bending and breaking of the flexible encapsulation layer existing in the existing flexible display panel.

Description

Technical Field

[0001] The present application relates to the field of displays, and in particular, to a flexible display panel, a preparation method thereof, and a display device. Background Art

[0002] As a new display technology, organic light emitting diode (OLED) display devices have the characteristics of wide color gamut, fast response, high contrast, and no need for backlight, and have been widely used in many fields such as displays and lighting.

[0003] In recent years, due to the unique device structure of OLEDs, flexible packaging can be achieved, resulting in an increasing demand for flexible OLEDs. However, limited by the packaging process, the product yield of flexible OLED devices is relatively low.

[0004] Among the many packaging defects, product defects in the bending area are the most common. This is mainly because most OLED flexible packaging uses two layers of polymer films. To ensure high transmittance on the light-emitting surface, high-crystalline transparent polymers are mostly used for the polymer materials on the light-emitting surface. And the high-crystalline transparent polymer film will be brittle and fractured to a certain extent due to bending. Summary of the Invention

[0005] The present invention provides a flexible display panel, a preparation method thereof, and a display device to solve the problem that the packaging layer is prone to brittle fracture when the flexible display panel is bent.

[0006] To solve the above problems, the technical solutions provided by the present invention are as follows:

[0007] The present invention provides a flexible display panel, which includes:

[0008] A flexible substrate;

[0009] A display functional layer disposed on one side of the flexible substrate;

[0010] A flexible packaging layer disposed on the side of the display functional layer away from the flexible substrate;

[0011] Wherein, the flexible packaging layer includes a strengthened packaging layer and a basic packaging layer. The strengthened packaging layer is disposed between the basic packaging layer and the display functional layer, and the strengthened packaging layer includes a strength strengthening material.

[0012] Optionally, in some embodiments of the present invention, the strength strengthening material is silver nanowires.

[0013] Optionally, in some embodiments of the present invention, the diameter range of the silver nanowires is 0.05 micrometers - 50 micrometers.

[0014] Optionally, in some embodiments of the present invention, the aspect ratio of the silver nanowires ranges from 2:1 to 3000:1.

[0015] Optionally, in some embodiments of the present invention, the reinforcing encapsulation layer is prepared from glue, and the glue includes the silver nanowires, and the mass concentration of the silver nanowires in the glue is greater than 70%.

[0016] Optionally, in some embodiments of the present invention, the reinforcing encapsulation layer further includes a dispersant, and the dispersant is a resin material with a transmittance greater than 85% and an elastic modulus less than 2000 MPa.

[0017] Optionally, in some embodiments of the present invention, the thickness range of the reinforcing encapsulation layer is from 50 nanometers to 50 micrometers.

[0018] Meanwhile, the present invention provides a method for manufacturing a flexible display panel, and the manufacturing method includes:

[0019] Providing a flexible substrate;

[0020] Preparing a display functional layer on the flexible substrate;

[0021] Providing a base encapsulation layer;

[0022] Preparing the first reinforcing encapsulation layer according to any one of the embodiments of the present invention on the base encapsulation layer;

[0023] Bonding the side of the first reinforcing encapsulation layer facing away from the base encapsulation layer to the display functional layer;

[0024] Curing the first reinforcing encapsulation layer.

[0025] Optionally, in some embodiments of the present invention, the manufacturing method further includes preparing a second reinforcing encapsulation layer on the side of the display functional layer facing away from the flexible substrate, and the material of the second reinforcing encapsulation layer is the same as that of the first reinforcing encapsulation layer; the specific steps of bonding the side of the first reinforcing encapsulation layer facing away from the base encapsulation layer to the side of the display functional layer facing away from the flexible substrate include:

[0026] Bonding the side of the second reinforcing encapsulation layer facing away from the display functional layer to the side of the first reinforcing encapsulation layer facing away from the base encapsulation layer.

[0027] Optionally, in some embodiments of the present invention, the specific steps of curing the first reinforcing encapsulation layer include:

[0028] Performing heat treatment on the first reinforcing encapsulation layer; the temperature of the heat treatment is 60 - 100 °C, and the time is 10 - 120 minutes.

[0029] Meanwhile, the present invention provides a display device, which includes an outer frame and the flexible display panel according to any one of the embodiments of the present invention, and the flexible display panel is disposed within the outer frame.

[0030] The present invention provides a flexible display panel, which includes: a flexible substrate; a display functional layer disposed on one side of the flexible substrate; a flexible encapsulation layer disposed on the side of the display functional layer away from the flexible substrate; wherein, the flexible encapsulation layer includes a reinforcement encapsulation layer and a base encapsulation layer, the reinforcement encapsulation layer is disposed between the base encapsulation layer and the display functional layer, and the reinforcement encapsulation layer includes a strength reinforcement material. By adding a reinforcement encapsulation layer including a strength reinforcement material between the base encapsulation layer and the display functional layer, and utilizing the high-strength characteristics of the strength reinforcement material, while not affecting the light extraction of the display panel, the strength of the flexible encapsulation layer is enhanced, realizing a flexible display panel with high-strength encapsulation and reducing the risk of bending and breaking of the flexible encapsulation layer existing in the existing flexible display panel. Description of the Drawings

[0031] The following will clearly and completely describe the technical solutions and other beneficial effects of the present application by combining the specific embodiments of the present application with reference to the drawings.

[0032] Figure 1 It is a schematic structural diagram of the flexible display panel provided by the embodiment of the present invention;

[0033] Figure 2 It is a flowchart of the preparation method of the flexible display panel provided by the embodiment of the present invention. Detailed Embodiments

[0034] The following will clearly and completely describe the technical solutions in the embodiments and / or examples of the present invention in combination with the specific implementation manners of the present invention. Obviously, the following described embodiments and / or examples are only a part of the embodiments and / or examples of the present invention, rather than all of the embodiments and / or examples. All other embodiments and / or examples obtained by those of ordinary skill in the art based on the embodiments and / or examples of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0035] The directional terms mentioned in the present invention, such as [up], [down], [left], [right], [front], [back], [inside], [outside], [side], etc., are only references to the directions in the attached drawings. Therefore, the directional terms used are for explaining and understanding the present invention, rather than for limiting the present invention. The terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first", "second", etc. may explicitly or implicitly include one or more of such features.

[0036] Aiming at the problem that the encapsulation layer of the existing flexible display panel is prone to brittle fracture when bent, the present invention provides a flexible display panel that can solve this problem.

[0037] In one embodiment, please refer to Figure 1 , Figure 1 which shows a schematic structural diagram of the flexible display panel provided by the embodiment of the present invention. As Figure 1 shown, the flexible display panel 1 provided by the embodiment of the present invention includes:

[0038] A flexible substrate 10;

[0039] A display functional layer 20, disposed on one side of the flexible substrate 10;

[0040] A flexible encapsulation layer 30, disposed on the side of the display functional layer 20 away from the flexible substrate 10;

[0041] Wherein, the flexible encapsulation layer 30 includes a reinforced encapsulation layer 31 and a basic encapsulation layer 32, the reinforced encapsulation layer 31 is disposed between the basic encapsulation layer 32 and the display functional layer 20, and the reinforced encapsulation layer 31 includes a strength reinforcing material.

[0042] In the embodiment of the present invention, by adding a reinforced encapsulation layer including a strength reinforcing material between the basic encapsulation layer and the display functional layer 20, and utilizing the high-strength characteristics of the strength reinforcing material, while not affecting the light extraction of the display panel, the strength of the flexible encapsulation layer 30 is enhanced, realizing a flexible display panel with high-strength encapsulation and reducing the risk of bending and fracture of the flexible encapsulation layer 30 existing in the existing flexible display panel.

[0043] Specifically, please refer to Figure 1, the flexible substrate 10 is a flexible polymer substrate, and the flexible polymer substrate is a polymer film having a single-layer or multi-layer composite structure. The material of the polymer film includes but is not limited to polyethylene, polystyrene, polyvinyl chloride, polyamide, polyimide, polyethylene naphthalate, polyethylene terephthalate, and homologues, isomers of the above materials, and polymers with hydrocarbon groups, aromatic rings or heterocyclic groups having 1-16 carbon (C) atoms, 1-9 nitrogen (N) atoms, and 1-5 oxygen (O) atoms, any one or more of them.

[0044] The display functional layer 20 includes a driving circuit layer 21, a first electrode 22, a second electrode 24, and a light-emitting layer 23 located between the first electrode 22 and the second electrode 24. A driving circuit is provided in the driving circuit layer 21, and the driving circuit is electrically connected to the first electrode 22 or the second electrode 24 for driving the light-emitting layer 23 to emit light for display. In the embodiment of the present invention, it may be that the first electrode 22 is the anode and the second electrode 24 is the cathode, or the first electrode 22 is the cathode and the second electrode is the anode, which is not limited.

[0045] The side of the second electrode 24 is the light-emitting side of the flexible display panel 1. Therefore, the first electrode 22 is a reflective electrode and the second electrode 24 is a transmissive electrode. The first electrode 22 is a film having a single-layer or multi-layer composite structure. The first electrode 22 includes a reflective layer, and the reflective layer is connected to the flexible substrate 10 for reflecting the light propagated from the light-emitting layer 23 to the first electrode 22, so that the flexible display panel 1 can obtain higher light extraction efficiency; the material of the reflective layer includes but is not limited to any one of metals such as silver (Ag), aluminum (Al), platinum (Pt), molybdenum (Mo), titanium (Ti), copper (Cu), etc., and the thickness of the reflective layer is 100 nanometers - 1000 nanometers. The first electrode 22 further includes an optical adjustment layer, and the optical adjustment layer is located on the side of the reflective layer away from the flexible substrate 10. The optical adjustment layer is constructed of a transparent conductive material. The material of the optical adjustment layer is generally any one or more of indium zinc oxide (IZO), indium tin oxide (ITO), aluminum zinc oxide (AZO), and other semiconductor materials with high transmittance and high conductivity, and the thickness of the optical adjustment layer is 1 nanometer - 100 nanometers.

[0046] The second electrode 24 is a film having a single-layer or multi-layer composite structure. The material of the second electrode 24 includes but is not limited to any one or more of metals such as silver (Ag), aluminum (Al), platinum (Pt), magnesium (Mg), etc. and their alloys, indium zinc oxide (IZO), indium tin oxide (ITO), aluminum zinc oxide (AZO), and other semiconductor materials with high transmittance and high conductivity, and the thickness of the second electrode 24 is 5 nanometers - 50 nanometers.

[0047] The light-emitting layer 23 generally includes a hole injection layer, a hole transport layer, a light-emitting material layer, an electron transport layer, an electron injection layer, an electron blocking layer between the hole transport layer and the light-emitting layer, and a hole blocking layer between the light-emitting layer and the electron transport layer. The light-emitting layer 23 is prepared by one or more of, but not limited to, vacuum evaporation, spin coating, printing, physical vapor deposition, chemical vapor deposition, and other physical / chemical deposition methods.

[0048] The base encapsulation layer 32 is a flexible polymer encapsulation layer. The base encapsulation layer 32 is a polymer film having a single-layer or multi-layer composite structure. The material of the polymer film includes, but is not limited to, polyethylene, polystyrene, polyvinyl chloride, polyamide, polyimide, polyethylene naphthalate, polyethylene terephthalate, and homologues, isomers of the above materials, and polymers having hydrocarbon groups, aromatic rings, or heterocyclic groups with 1-16 carbon (C) atoms, 1-9 nitrogen (N) atoms, and 1-5 oxygen (O) atoms added thereto, any one or more of them.

[0049] The reinforcing encapsulation layer 31 is disposed between the second electrode 24 and the base encapsulation layer 32. The thickness range of the reinforcing encapsulation layer 31 is generally 50 nanometers to 50 micrometers, which is much smaller than the thickness of the base encapsulation layer 32. Therefore, the setting of the reinforcing encapsulation layer 31 hardly increases the thickness of the overall encapsulation layer, and even less causes an increase in the thickness of the flexible display panel 1. The reinforcing encapsulation layer 31 is prepared by a preparation process such as spin coating, blade coating, slot coating, inkjet printing, etc. using glue. The glue includes silver nanowires and a dispersant. The diameter range of the silver nanowires is 0.05 micrometers to 50 micrometers, and the aspect ratio range of the silver nanowires is 2:1 to 3000:1. The concentration of the silver nanowires in the glue is greater than 70%; the dispersant is a resin material with a transmittance greater than 85% and an elastic modulus less than 2000 MPa. The dispersant includes, but is not limited to, epoxy resin or phenolic resin. In this way, the prepared reinforcing encapsulation layer 31 has the characteristics of high transmittance and high strength, does not affect the light output effect of the display panel 1, and at the same time enhances the strength of the entire flexible encapsulation layer 30, reduces the risk of bending and breaking of the flexible encapsulation layer 30, and realizes a flexible display panel 1 with high-strength encapsulation.

[0050] Correspondingly, the present invention also provides a method for manufacturing a flexible display panel for manufacturing the flexible display panel provided by the embodiments of the present invention. Please refer to Figure 2 , Figure 2 shows a flowchart of the method for manufacturing the flexible display panel provided by the embodiments of the present invention. As Figure 2 shown, the manufacturing method includes:

[0051] S11. Provide a flexible substrate;

[0052] S12. Prepare a display functional layer on the flexible substrate;

[0053] S21. Provide a basic encapsulation layer;

[0054] S22. Prepare the first enhanced encapsulation layer according to any one of the embodiments of the present invention on the basic encapsulation layer;

[0055] S3. Bond the side of the first enhanced encapsulation layer facing away from the basic encapsulation layer to the side of the display functional layer facing away from the flexible substrate;

[0056] S4. Cure the first enhanced encapsulation layer.

[0057] Specifically, in step S11, providing the flexible substrate means providing the flexible polymer substrate, and the flexible substrate 10 is a polymer film with a single-layer or multi-layer composite structure.

[0058] In step S12, preparing the display functional layer 20 on the flexible substrate includes successively preparing the driving circuit layer 21, the first electrode 22, the light-emitting layer 23, and the second electrode 24 on the flexible substrate.

[0059] In step S21, providing the basic encapsulation layer means providing the flexible polymer encapsulation layer, and the basic encapsulation layer 32 is a polymer film with a single-layer or multi-layer composite structure.

[0060] The step of preparing the first enhanced encapsulation layer according to any one of the embodiments of the present invention on the basic encapsulation layer in step S22 includes:

[0061] Coat a glue containing silver nanowires and a dispersant on the basic encapsulation layer 32 by processes such as spin coating, blade coating, slot die coating, inkjet printing, etc.;

[0062] Among them, the silver nanowires are the strength enhancing materials, the diameter range of the silver nanowires is 0.05 μm - 50 μm, the aspect ratio range is 2 - 3000, and the concentration of the silver nanowires in the glue is greater than 70%.

[0063] The step of bonding the side of the first enhanced encapsulation layer facing away from the basic encapsulation layer to the side of the display functional layer facing away from the flexible substrate in step S3 includes:

[0064] Bond the side of the second electrode 24 facing away from the flexible substrate to the side of the first enhanced encapsulation layer facing away from the basic encapsulation layer.

[0065] The step of curing the first enhanced encapsulation layer in step S4 includes:

[0066] Perform heat treatment on the first enhanced encapsulation layer to cure the first enhanced encapsulation layer and tightly connect it to the second electrode 24, thereby integrating the first enhanced encapsulation layer, the basic encapsulation layer 32, the display function layer 20, and the flexible substrate 10 into one; the temperature of the heat treatment is 60 - 100 °C, and the treatment time is 10 - 120 minutes.

[0067] In one embodiment, the preparation method further includes, after step S12, preparing a second enhanced encapsulation layer on the side of the display function layer 20 facing away from the flexible substrate. Then, the step of attaching the side of the first enhanced encapsulation layer facing away from the basic encapsulation layer to the side of the display function layer facing away from the flexible substrate in step S3 includes:

[0068] Attach the side of the second enhanced encapsulation layer facing away from the display function layer to the side of the first enhanced encapsulation layer facing away from the basic encapsulation layer.

[0069] The step of curing the first enhanced encapsulation layer in step S4 includes:

[0070] Perform heat treatment on the first enhanced encapsulation layer and the second enhanced encapsulation layer to cure and tightly connect the first enhanced encapsulation layer and the second enhanced encapsulation layer, thereby integrating the first enhanced encapsulation layer, the basic encapsulation layer 32, the second enhanced encapsulation layer, the display function layer 20, and the flexible substrate 10 into one; the temperature of the heat treatment is 60 - 100 °C, and the treatment time is 10 - 120 minutes.

[0071] An embodiment of the present invention further provides a display device, which includes a frame and the flexible display panel according to any one of the embodiments of the present invention, and the flexible display panel is disposed within the frame.

[0072] In summary, the embodiments of the present invention provide a flexible display panel, a preparation method thereof, and a display device. The flexible display panel includes: a flexible substrate; a display function layer disposed on one side of the flexible substrate; a flexible encapsulation layer disposed on the side of the display function layer away from the flexible substrate; wherein, the flexible encapsulation layer includes an enhanced encapsulation layer and a basic encapsulation layer, the enhanced encapsulation layer is disposed between the basic encapsulation layer and the display function layer, and the enhanced encapsulation layer includes a strength enhancing material. By adding an enhanced encapsulation layer including a strength enhancing material between the basic encapsulation layer and the display function layer, and utilizing the high strength characteristics of the strength enhancing material, while not affecting the light extraction of the display panel, the strength of the flexible encapsulation layer is enhanced, realizing a flexible display panel with high strength encapsulation and reducing the risk of bending and breaking of the flexible encapsulation layer existing in the existing flexible display panel.

[0073] The above has introduced in detail the flexible display panel provided by the embodiments of the present invention. Specific examples are used herein to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those skilled in the art, according to the idea of the present invention, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A flexible display panel, characterized in that, Comprising: A flexible substrate; A display functional layer disposed on one side of the flexible substrate; A flexible encapsulation layer disposed on the side of the display functional layer away from the flexible substrate; Wherein, the flexible encapsulation layer includes a base encapsulation layer and a reinforcement encapsulation layer, the reinforcement encapsulation layer is disposed between the base encapsulation layer and the display functional layer, and the reinforcement encapsulation layer includes a strength reinforcement material; The strength reinforcement material is silver nanowires.

2. The flexible display panel according to claim 1, wherein The diameter range of the silver nanowires is 0.05 μm - 50 μm.

3. The flexible display panel according to claim 2, wherein The aspect ratio range of the silver nanowires is 2:1 - 3000:

1.

4. The flexible display panel according to claim 1, wherein The reinforcement encapsulation layer is prepared from glue, the glue includes the silver nanowires, and the mass concentration of the silver nanowires in the glue is greater than 70%.

5. The flexible display panel according to claim 1, wherein, The reinforcement encapsulation layer further includes a dispersant, and the dispersant is a resin material with a transmittance greater than 85% and an elastic modulus less than 2000 MPa.

6. The flexible display panel according to claim 1, wherein The thickness range of the reinforcement encapsulation layer is 50 nm - 50 μm.

7. A method for manufacturing a flexible display panel, which is used to manufacture the flexible display panel according to any one of claims 1 to 6, characterized in that, The reinforcement encapsulation layer includes a first reinforcement encapsulation layer; The preparation method includes: Providing a flexible substrate; Preparing a display functional layer on the flexible substrate; Providing a base encapsulation layer; Preparing the first reinforcement encapsulation layer on the base encapsulation layer; Bonding the side of the first reinforcement encapsulation layer away from the base encapsulation layer to the side of the display functional layer away from the flexible substrate; Curing the first reinforcement encapsulation layer.

8. The preparation method according to claim 7, wherein The preparation method further includes preparing a second reinforcement encapsulation layer on the side of the display functional layer away from the flexible substrate, and the material of the second reinforcement encapsulation layer is the same as that of the first reinforcement encapsulation layer; the specific steps of bonding the side of the first reinforcement encapsulation layer away from the base encapsulation layer to the side of the display functional layer away from the flexible substrate include: Bonding the side of the second reinforcement encapsulation layer away from the display functional layer to the side of the first reinforcement encapsulation layer away from the base encapsulation layer.

9. The preparation method according to claim 7 or 8, characterized in that, The specific steps of curing the first reinforcement encapsulation layer include: Performing heat treatment on the first reinforcement encapsulation layer; the temperature of the heat treatment is 60 - 100 °C, and the time is 10 - 120 minutes.

10. A display device, characterized in that, Including a frame and the flexible display panel according to any one of claims 1 to 6, and the flexible display panel is disposed within the frame.

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