Flexible display panel, preparation method thereof, and display device

Abstract

The present invention provides a flexible display panel, a manufacturing method thereof, and a display device. The flexible display panel includes: a first conductive layer group; a light-emitting layer group formed on the first conductive layer group, the light-emitting layer group including a pixel definition layer and a light-emitting layer matched with the pixel definition layer; and a second conductive layer group formed on the light-emitting layer group, wherein the pixel definition layer includes a stacked first sub-pixel definition layer and a second sub-pixel definition layer, the light-emitting layer is located within an opening defined by the first sub-pixel definition layer, the second sub-pixel definition layer covers a top portion of the first sub-pixel definition layer, a positive projection of the second sub-pixel definition layer on a plane where the first conductive layer group is located overlaps with a part of the positive projection of the opening on the plane where the first conductive layer group is located, the second sub-pixel definition layer is tightly combined with the second conductive layer group and is an inorganic layer, and the inorganic layer tightly surrounds a part of the second conductive layer group received in the opening circumferentially and extends to contact the light-emitting layer.

Description

[0001] This application is a divisional application of the invention patent application with the application date of June 19, 2018, the title of "Flexible Display Panel and Its Preparation Method and Display Device", and the application number of 201810629944.3. Technical Field

[0002] The present invention relates to the field of display technologies, and particularly to a flexible display panel and its preparation method and a display device. Background Art

[0003] For a usage environment that requires repeated folding, a flexible display panel naturally has good adaptability, enabling the flexible display panel to have a wide range of application fields. In the prior art, during the use of a flexible display panel, the cathode layer is prone to peeling off, thus causing abnormal display. Summary of the Invention

[0004] In view of this, embodiments of the present invention provide a flexible display panel and its preparation method and a display device, which can solve the defect of peeling off of the cathode layer during the use of the flexible display panel, thereby solving the problem of abnormal display. This is particularly applicable to active matrix organic light-emitting diodes (AMOLEDs).

[0005] One aspect of the present invention provides a flexible display panel, including: a first conductive layer group; a light-emitting layer group formed on the first conductive layer group, the light-emitting layer group including a pixel definition layer and a light-emitting layer matching the pixel definition layer; and a second conductive layer group formed on the light-emitting layer group, wherein the pixel definition layer includes a stacked first sub-pixel definition layer and a second sub-pixel definition layer, and the second sub-pixel definition layer is tightly combined with the second conductive layer group.

[0006] In an embodiment of the present invention, the second conductive layer group includes a stacked first sub-conductive layer and a second sub-conductive layer. The first sub-conductive layer and the light-emitting layer are surrounded by the first sub-pixel definition layer, and the second sub-pixel definition layer is on the first sub-pixel definition layer and partially covers the first sub-conductive layer.

[0007] In an embodiment of the present invention, the thickness of the first sub-pixel definition layer is the sum of the thicknesses of the light-emitting layer and the first sub-conductive layer.

[0008] In an embodiment of the present invention, the thickness of the second sub-pixel definition layer is less than the thickness of the first sub-pixel definition layer.

[0009] In an embodiment of the present invention, the first sub-pixel definition layer and the second sub-pixel definition layer are made of the same material.

[0010] In one embodiment of the present invention, the second sub-pixel defining layer is an inorganic layer and covers the top portion of the first sub-pixel defining layer, and the inorganic layer tightly surrounds the first sub-conductive layer circumferentially; preferably, the inorganic layer extends to contact the light-emitting layer.

[0011] In one embodiment of the present invention, the second sub-conductive layer is on the first sub-conductive layer and covers the pixel defining layer.

[0012] In one embodiment of the present invention, the first conductive layer group is an array substrate, and the second conductive layer group is a cathode layer.

[0013] Another aspect of the present invention provides a display device, including the flexible display panel as described above.

[0014] Another aspect of the present invention provides a method for manufacturing a flexible display panel, including: forming a first conductive layer group on a substrate; forming a first sub-pixel defining layer having an opening on the first conductive layer group; forming a light-emitting layer in the opening of the first sub-pixel defining layer; forming a second conductive layer group on the light-emitting layer; and forming a second sub-pixel defining layer on the first sub-pixel defining layer, wherein the second pixel defining layer is tightly combined with the second conductive layer group.

[0015] According to the technical solution provided by the embodiments of the present invention, by adopting the structure of the second sub-pixel defining layer, the pressing force of the second sub-pixel defining layer on the second conductive layer group is increased. Therefore, the separation of the second conductive layer group and the light-emitting layer is avoided, and the display effect of the flexible display panel is further improved.

[0016] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present invention. Description of the Drawings

[0017] Figure 1 is a schematic diagram of a flexible display panel shown according to an exemplary embodiment of the present invention.

[0018] Figure 2 is a schematic diagram of a flexible display panel shown according to another exemplary embodiment of the present invention.

[0019] Figure 3 is a flowchart of a method for manufacturing a flexible display panel shown according to an exemplary embodiment of the present invention. Detailed Embodiments

[0020] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0021] Figure 1 It is a schematic diagram of a flexible display panel shown according to an exemplary embodiment of the present invention. As Figure 1 shown, the flexible display panel includes: a first conductive layer group 10; a light-emitting layer group 11 formed on the first conductive layer group 10, the light-emitting layer group 11 including a pixel definition layer 111 and a light-emitting layer 112 matching the pixel definition layer 111; and a second conductive layer group 12 formed on the light-emitting layer group 11, wherein the pixel definition layer 111 includes a stacked first sub-pixel definition layer 1111 and a second sub-pixel definition layer 1112, and the second sub-pixel definition layer 1112 is tightly combined with the second conductive layer group 12.

[0022] In the embodiment of the present invention, the first conductive layer group 10 may be a thin film transistor (TFT) array substrate, or may be a low temperature poly-silicon (LTPS) array substrate, or may also be a hybrid thin film transistor array substrate, etc., and the present invention does not limit this.

[0023] The light-emitting layer group 11 is formed on the first conductive layer group 10 and includes a pixel definition layer 111 and a light-emitting layer 112 matching the pixel definition layer 111. The light-emitting layer 112 may be an organic light-emitting diode (OLED) layer, or may be a micro light-emitting diode (μLED) layer, or may also be a quantum dot light-emitting diode (QLED) layer, etc., and the present invention does not limit this.

[0024] The pixel definition layer 111 includes a first sub-pixel definition layer 1111 and a second sub-pixel definition layer 1112 located on the first sub-pixel definition layer 1111. The material of the first sub-pixel definition layer 1111 may include but is not limited to polyimide (PI), polyamide (PA), benzocyclobutene (BCB), acrylic resin or phenolic resin, etc. The material of the second sub-pixel definition layer 1112 may include but is not limited to polyimide (PI), polyamide (PA), benzocyclobutene (BCB), acrylic resin or phenolic resin, etc.

[0025] It should be noted that the materials of the first sub-pixel definition layer 1111 and the second sub-pixel definition layer 1112 may be the same or different, and the present invention does not limit this. Preferably, the first sub-pixel definition layer 1111 and the second sub-pixel definition layer 1112 are made of the same material.

[0026] The second conductive layer group 12 may be a cathode layer. The second conductive layer group 12 is formed on the light-emitting layer group 11, and the second sub-pixel definition layer 1112 is tightly combined with the second conductive layer group 12. The material of the second conductive layer group 12 may be a metal such as magnesium (Mg), silver (Ag), aluminum (Al), etc., or a metal oxide such as indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), etc., or may also be an alloy such as aluminum fluoride / lithium (Al / LiF), aluminum lithium (AlLi), etc., and the present invention does not limit this.

[0027] According to the technical solution provided by the embodiment of the present invention, by adopting the structure of the second sub-pixel definition layer, the bonding force of the second sub-pixel definition layer to the second conductive layer group is increased. Therefore, the separation of the second conductive layer group and the light-emitting layer is avoided, and the display effect of the flexible display panel is further improved.

[0028] In another embodiment of the present invention, the second conductive layer group includes a stacked first sub-conductive layer and a second sub-conductive layer. The first sub-conductive layer and the light-emitting layer are surrounded by the first sub-pixel definition layer, and the second sub-pixel definition layer is on the first sub-pixel definition layer and partially covers the first sub-conductive layer. In this way, the second sub-pixel definition layer generates a pressing force on the first sub-conductive layer of the second conductive layer group. Therefore, the separation of the second conductive layer group and the light-emitting layer is avoided, and the display effect of the flexible display panel is further improved. Specifically, the second conductive layer group 12 includes a first sub-conductive layer 121 and a second sub-conductive layer 122 located on the first sub-conductive layer 121. The second sub-conductive layer 122 covers the pixel definition layer 111. The material of the first sub-conductive layer 121 may include but is not limited to magnesium (Mg), silver (Ag), aluminum (Al), indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), aluminum fluoride / lithium (Al / LiF), aluminum lithium (AlLi), etc. The material of the second sub-conductive layer 122 may include but is not limited to magnesium (Mg), silver (Ag), aluminum (Al), indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), aluminum fluoride / lithium (Al / LiF), aluminum lithium (AlLi), etc.

[0029] It should be noted that the materials of the first sub-conductive layer 121 and the second sub-conductive layer 122 may be the same or different, and the present invention does not limit this. In addition, it should also be noted that when the materials of the first sub-conductive layer 121 and the second sub-conductive layer 122 are the same, the elastic moduli of the first sub-conductive layer 121 and the second sub-conductive layer 122 are the same. Therefore, the stress matching is better, enabling good electrical contact between the first sub-conductive layer 121 and the second sub-conductive layer 122, thereby improving the display quality.

[0030] Further, the total thickness of the first sub-conductive layer 121 and the second sub-conductive layer 122 is in the range of 100 nm to 300 nm. Preferably, the total thickness of the first sub-conductive layer 121 and the second sub-conductive layer 122 is 180 nm. The thickness of the first sub-conductive layer 121 may be greater than or equal to the thickness of the second sub-conductive layer 122, or may be less than or equal to the thickness of the second sub-conductive layer 122, and the present invention does not limit this.

[0031] In another embodiment of the present invention, the thickness of the first sub-pixel defining layer is the sum of the thicknesses of the light-emitting layer and the first sub-conductive layer.

[0032] Specifically, the thickness of the light-emitting layer 112 is less than the thickness of the first sub-pixel defining layer 1111, and the thickness of the first sub-conductive layer 121 is less than the thickness of the first sub-pixel defining layer 1111. The sum of the thicknesses of the light-emitting layer 112 and the first sub-conductive layer 121 is substantially equal to the thickness of the first sub-pixel defining layer 1111. Preferably, the thickness of the light-emitting layer 112 is half of the thickness of the first sub-pixel defining layer 1111, and the thickness of the first sub-conductive layer 121 is also half of the thickness of the first sub-pixel defining layer 1111.

[0033] In another embodiment of the present invention, the thickness of the second sub-pixel defining layer is less than the thickness of the first sub-pixel defining layer.

[0034] Specifically, the thickness of the second sub-pixel defining layer 1112 may be greater than, less than, or equal to the thickness of the first sub-pixel defining layer 1111. Preferably, the thickness of the second sub-pixel defining layer 1112 is less than the thickness of the first sub-pixel defining layer 1111. Further, the total thickness of the first sub-pixel defining layer 1111 and the second sub-pixel defining layer 1112 is in the range of 1 μm to 3 μm. Preferably, the total thickness of the first sub-pixel defining layer 1111 and the second sub-pixel defining layer 1112 is 1.605 μm.

[0035] In another embodiment of the present invention, the second sub-pixel defining layer is an inorganic layer and covers the top portion of the first sub-pixel defining layer, and the inorganic layer circumferentially and tightly surrounds the first sub-conductive layer; preferably, the inorganic layer extends to contact the light-emitting layer.

[0036] Specifically, the second sub-pixel definition layer 1112 is an inorganic layer and covers the top portion of the first sub-pixel definition layer 1111. The inorganic layer circumferentially and tightly surrounds the first sub-conductive layer 121. Preferably, the inorganic layer extends to contact the light-emitting layer 112. Here, the material of the inorganic layer may include, but is not limited to, silicon oxide (SiOx), silicon nitride (SiNx), silicon oxynitride (SiOxNy), aluminum oxide (AlOx), aluminum nitride (AlOx), etc.

[0037] Any combination of the above optional technical solutions can be adopted to form an optional embodiment of the present invention, which will not be elaborated here one by one.

[0038] Figure 2 is a schematic diagram of a flexible display panel shown according to another exemplary embodiment of the present invention. As Figure 2 shown, the flexible display panel includes: a first conductive layer group 20; a light-emitting layer group 21 formed on the first conductive layer group 20, the light-emitting layer group 21 including a pixel definition layer 211 and a light-emitting layer 212 matching the pixel definition layer 211; and a second conductive layer group 22 formed on the light-emitting layer group 21, wherein the pixel definition layer 211 includes a stacked first sub-pixel definition layer 2111 and a second sub-pixel definition layer 2112, and the second sub-pixel definition layer 2112 is tightly combined with the second conductive layer group 22.

[0039] It should be noted that Figure 2 the structure of the flexible display panel shown is basically the same as that of the flexible display panel shown in Figure 1 Therefore, only the differences will be described below.

[0040] Specifically, the second sub-pixel definition layer 2112 is an inorganic layer and covers the top portion of the first sub-pixel definition layer 2111. Here, the material of the inorganic layer may include, but is not limited to, silicon oxide (SiOx), silicon nitride (SiNx), silicon oxynitride (SiOxNy), aluminum oxide (AlOx), aluminum nitride (AlOx), etc.

[0041] Furthermore, the cross-section of the inorganic layer may be an inverted L shape. The inorganic layer circumferentially and tightly surrounds the first sub-conductive layer 121. Preferably, it extends to contact the light-emitting layer 212.

[0042] In addition, the second conductive layer group 22 may include a first sub-conductive layer 221 and a second sub-conductive layer 222 located on the first sub-conductive layer 221. The thickness of the inorganic layer may be less than or equal to the thickness of the second sub-conductive layer 222. Preferably, the thickness of the inorganic layer is less than the thickness of the second sub-conductive layer 222.

[0043] According to the technical solution provided by the embodiment of the present invention, by adopting the structure of the inorganic layer, the adhesion between the inorganic layer and the first sub-conductive layer is increased, so that the first sub-conductive layer and the inorganic layer do not generate relative movement. Therefore, the separation of the first sub-conductive layer and the light-emitting layer is avoided, and the display effect of the flexible display panel is further improved.

[0044] An embodiment of the present invention also provides a display device, including the flexible display panel as described above.

[0045] Figure 3 It is a flowchart of a method for manufacturing a flexible display panel shown according to an exemplary embodiment of the present invention. As Figure 3 shown, the method for manufacturing the flexible display panel includes:

[0046] 310: Form a first conductive layer group on a substrate.

[0047] In the embodiment of the present invention, through a series of methods such as Chemical Vapor Deposition (CVD), Physical Vapor Deposition (PVD), photolithography, and etching, a first conductive layer group is formed on a cleaned substrate. Here, the substrate can be a flexible substrate, and the flexible substrate can be transparent, semi-transparent, or opaque. Preferably, the flexible substrate is a transparent glass substrate. The first conductive layer group can include, but is not limited to, a TFT array substrate, an LTPS array substrate, a hybrid thin-film transistor array substrate, etc. Preferably, the first conductive layer group is a TFT array substrate.

[0048] 320: Form a first sub-pixel defining layer with openings on the first conductive layer group.

[0049] In the embodiment of the present invention, through a coating or deposition method, a first sub-pixel defining layer is formed on the first conductive layer group, and the first sub-pixel defining layer has openings.

[0050] 330: Form a light-emitting layer in the openings of the first sub-pixel defining layer.

[0051] In the embodiment of the present invention, through an evaporation process, a light-emitting layer is formed in the openings of the first sub-pixel defining layer, and the light-emitting layer covers a part of the first conductive layer group exposed from the openings of the first sub-pixel defining layer.

[0052] 340: Form a second conductive layer group on the light-emitting layer.

[0053] In an embodiment of the present invention, a second conductive layer group is formed on the light-emitting layer by means of evaporation coating or the like. The second conductive layer group includes a first sub-conductive layer and a second sub-conductive layer located on the first sub-conductive layer. The first sub-conductive layer is located within the opening of the first sub-pixel defining layer, and the upper surface of the first sub-conductive layer is flush with the upper surface of the first sub-pixel defining layer.

[0054] 350: A second sub-pixel defining layer is formed on the first sub-pixel defining layer.

[0055] In an embodiment of the present invention, a second sub-pixel defining layer is formed on the first sub-pixel defining layer by means of coating or deposition. The second sub-pixel defining layer covers a part of the first sub-conductive layer.

[0056] According to the technical solution provided by the embodiment of the present invention, by adopting the structure of the second sub-pixel defining layer, the pressing force of the second sub-pixel defining layer on the second conductive layer group is increased. Therefore, the separation of the second conductive layer group and the light-emitting layer is avoided, and the display effect of the flexible display panel is further improved.

[0057] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A flexible display panel, characterized in that, Comprising: A first conductive layer group; A light-emitting layer group formed on the first conductive layer group, the light-emitting layer group including a pixel definition layer and a light-emitting layer matching the pixel definition layer; And A second conductive layer group, formed on the light-emitting layer group, wherein the pixel definition layer includes a stacked first sub-pixel definition layer and a second sub-pixel definition layer, the light-emitting layer is located within an opening defined by the first sub-pixel definition layer, the second sub-pixel definition layer covers a top portion of the first sub-pixel definition layer, a positive projection of the second sub-pixel definition layer on a plane where the first conductive layer group is located overlaps with a part of the positive projection of the opening on the plane where the first conductive layer group is located, and the second sub-pixel definition layer is tightly combined with the second conductive layer group; The second sub-pixel definition layer is an inorganic layer, the inorganic layer circumferentially and tightly surrounds a portion of the second conductive layer group received in the opening and extends to contact the light-emitting layer, so that the second sub-pixel definition layer covers a part of the side surface of the first sub-pixel definition layer, and the second conductive layer group and the first sub-pixel definition layer are completely spaced apart by the second sub-pixel definition layer.

2. The flexible display panel according to claim 1, characterized in that, The thickness of the first sub-pixel definition layer is the sum of the thicknesses of the light-emitting layer and the first conductive layer.

3. The flexible display panel according to claim 1 or 2, characterized in that The thickness of the second sub-pixel definition layer is less than the thickness of the first sub-pixel definition layer.

4. The flexible display panel according to claim 1 or 2, characterized in that, The first sub-pixel definition layer and the second sub-pixel definition layer are made of the same material.

5. The flexible display panel according to claim 1 or 2, wherein The first conductive layer group is an array substrate, and the second conductive layer group is a cathode layer.

6. A display device, characterized in that, A flexible display panel comprising any one of claims 1 to 5.

7. A method for preparing a flexible display panel, characterized in that, Comprising: Forming a first conductive layer group on a substrate; Forming a first sub-pixel definition layer having an opening on the first conductive layer group; Forming a light-emitting layer within the opening of the first sub-pixel definition layer; Forming a part of the second conductive layer group on the light-emitting layer and forming a second sub-pixel definition layer on the first sub-pixel definition layer, wherein the second sub-pixel definition layer is formed to cover a top portion of the first sub-pixel definition layer, a positive projection of the second sub-pixel definition layer on a plane where the first conductive layer group is located overlaps with a part of the positive projection of the opening on the plane where the first conductive layer group is located, the second sub-pixel definition layer is tightly combined with the second conductive layer group, and The second sub-pixel definition layer is an inorganic layer, the inorganic layer circumferentially and tightly surrounds a portion of the second conductive layer group received in the opening and extends to contact the light-emitting layer, so that the second sub-pixel definition layer covers a part of the side surface of the first sub-pixel definition layer, and the second conductive layer group and the first sub-pixel definition layer are completely spaced apart by the second sub-pixel definition layer.

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