Method for manufacturing display panel and display panel

Abstract

The application belongs to the technical field of display, and particularly relates to a preparation method of a display panel and the display panel. The preparation method comprises the following steps: providing a substrate, wherein a pixel definition layer is formed on the substrate, and the pixel definition layer has a plurality of openings; forming an organic light-emitting unit in the openings; forming a first inorganic encapsulation layer on the organic light-emitting unit and the pixel definition layer; forming a first organic encapsulation layer on the first inorganic encapsulation layer; forming a black matrix on the first organic encapsulation layer; and sequentially forming a second organic encapsulation layer and a second inorganic encapsulation layer on the first organic encapsulation layer, wherein the second organic encapsulation layer covers the black matrix. The application can improve the display effect and light extraction efficiency under a large viewing angle.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of display, and particularly relates to a preparation method of a display panel and the display panel. BACKGROUND

[0002] Organic light-emitting diode (OLED) display devices are widely used due to their self-luminous and high contrast characteristics. In order to improve brightness and reduce power consumption, the industry adopts a COE structure (Color Filter On Encapsulation) to replace the polarizer which will lose light efficiency, by directly manufacturing a color filter on an encapsulation layer.

[0003] However, in the COE structure, the black matrix located thereon is far away from the light-emitting layer of the organic light-emitting diode below, which causes the oblique light emitted by the light-emitting layer to be blocked by the black matrix, resulting in a decrease in brightness and color distortion of the display panel at a large viewing angle, and the overall light efficiency is affected. SUMMARY

[0004] The present application aims to provide a preparation method of a display panel and the display panel, which can improve the display effect and light efficiency at a large viewing angle.

[0005] The first aspect of the present application provides a preparation method of a display panel, comprising the following steps: providing a substrate, a pixel definition layer is formed on the substrate, and the pixel definition layer has a plurality of openings; forming an organic light-emitting unit in the openings; forming a first inorganic encapsulation layer on the organic light-emitting unit and the pixel definition layer; forming a first organic encapsulation layer on the first inorganic encapsulation layer; forming a black matrix on the first organic encapsulation layer; sequentially forming a second organic encapsulation layer and a second inorganic encapsulation layer on the first organic encapsulation layer, and the second organic encapsulation layer covers the black matrix.

[0006] In an exemplary embodiment of the present application, the step of forming the black matrix further comprises the step of forming a plurality of color resist on the first organic encapsulation layer, and the black matrix and the color resist constitute a color filter layer.

[0007] In an exemplary embodiment of the present application, after the first inorganic encapsulation layer is formed and before the first organic encapsulation layer is formed, the method further comprises the steps of: patterning the first inorganic encapsulation layer to expose part of the pixel definition layer; thinning the exposed pixel definition layer; forming a conductive layer, the conductive layer covering at least the thinned pixel definition layer; and forming an intermediate inorganic encapsulation layer on the conductive layer.

[0008] The second aspect of the present application provides a preparation method of a display panel, comprising the following steps: providing a substrate; forming a pixel definition layer on the substrate, the pixel definition layer having a plurality of openings and comprising a plurality of arrayed pixel definition portions, each of the pixel definition portions comprising a first portion, a second portion, and a transparent electrode between the first portion and the second portion; forming an organic light-emitting unit in the openings, a cathode of the organic light-emitting unit being electrically connected with the transparent electrode; forming a first inorganic encapsulation layer on the organic light-emitting unit and the pixel definition layer, and performing a patterning process on the first inorganic encapsulation layer to expose the second portion of the pixel definition portion; etching and removing the exposed second portion and the cathode on the second portion until etching stops at the transparent electrode; sequentially forming an intermediate inorganic encapsulation layer, a black matrix, an organic encapsulation layer, and a second inorganic encapsulation layer on the transparent electrode and the first inorganic encapsulation layer.

[0009] The third aspect of the present application provides a preparation method of a display panel, comprising the following steps: providing a substrate; forming a pixel definition layer on the substrate, the pixel definition layer having a plurality of openings and comprising a plurality of arrayed pixel definition portions, each of the pixel definition portions comprising a first portion, a second portion, and a transparent electrode and a black matrix between the first portion and the second portion, the black matrix being arranged on a side of the transparent electrode close to the first portion; forming an organic light-emitting unit in the openings, a cathode of the organic light-emitting unit being electrically connected with the transparent electrode; forming a first inorganic encapsulation layer on the organic light-emitting unit and the pixel definition layer, and performing a patterning process on the first inorganic encapsulation layer to expose the second portion of the pixel definition portion; etching and removing the exposed second portion and the cathode on the second portion until etching stops at the transparent electrode; sequentially forming an intermediate inorganic encapsulation layer, an organic encapsulation layer, and a second inorganic encapsulation layer on the transparent electrode and the first inorganic encapsulation layer.

[0010] The fourth aspect of the present application provides a preparation method of a display panel, comprising the following steps: providing a substrate; forming a pixel definition layer on the substrate, the pixel definition layer having a plurality of openings and comprising a plurality of arrayed pixel definition portions, each of the pixel definition portions comprising a first portion, a second portion, and a sacrificial layer and a black matrix between the first portion and the second portion, the black matrix being arranged on a side of the sacrificial layer close to the first portion; removing the sacrificial layer, so that the sacrificial layer is decomposed and the second portion is removed, thereby exposing the black matrix and the first portion; forming an organic light-emitting unit on the exposed black matrix and first portion and in the openings; forming a thin-film encapsulation layer on the organic light-emitting unit.

[0011] The fifth aspect of the present application provides a display panel, comprising: a substrate substrate; a pixel definition layer and an organic light emitting unit arranged on the substrate substrate; a first inorganic encapsulation layer covering the organic light emitting unit; a first organic encapsulation layer arranged on the first inorganic encapsulation layer; a black matrix arranged on the first organic encapsulation layer; and a second organic encapsulation layer and a second inorganic encapsulation layer sequentially formed on the first organic encapsulation layer, wherein the second organic encapsulation layer covers the black matrix.

[0012] In an example embodiment of the present application, the pixel definition layer has a thinning structure in a region corresponding to the black matrix; between the first inorganic encapsulation layer and the first organic encapsulation layer, a conductive layer and an intermediate inorganic encapsulation layer are sequentially arranged, wherein the conductive layer is at least covered on the pixel definition layer with the thinning structure, and the intermediate inorganic encapsulation layer covers the conductive layer.

[0013] The sixth aspect of the present application provides a display panel, comprising: a substrate substrate; a pixel definition layer arranged on the substrate substrate, wherein the pixel definition layer has a plurality of openings and comprises a plurality of arrayed pixel definition portions, each of the pixel definition portions comprises a first part and a transparent electrode arranged on the first part; a black matrix arranged on a side of the transparent electrode away from the first part, or arranged on a side of the transparent electrode close to the first part; an organic light emitting unit arranged in the opening, wherein a cathode of the organic light emitting unit is electrically connected with the transparent electrode; a first inorganic encapsulation layer arranged in the opening and covering the organic light emitting unit; an intermediate inorganic encapsulation layer covering the transparent electrode and the first inorganic encapsulation layer; an organic encapsulation layer and a second inorganic encapsulation layer covering the intermediate inorganic encapsulation layer.

[0014] The seventh aspect of the present application provides a display panel, comprising: a substrate substrate; a pixel definition layer arranged on the substrate substrate, wherein the pixel definition layer has a plurality of openings and comprises a plurality of arrayed pixel definition portions, each of the pixel definition portions comprises a first part and a black matrix arranged on the first part; an organic light emitting unit arranged in the opening; and a thin film encapsulation layer covering the organic light emitting unit.

[0015] The display panel provided by the present application has at least the following beneficial effects:

[0016] The preparation methods and corresponding structures provided by the present application can effectively reduce the vertical spacing between the black matrix and the organic light-emitting unit by constructing the organic encapsulation layer in steps, embedding the black matrix therebetween, using the transparent electrode as an etching stop layer to selectively remove part of the pixel definition layer to control the structure height, or by introducing a sacrificial layer and combining a stripping process to reduce the height of the pixel definition layer in advance. This structural improvement reduces the shielding effect of the black matrix on the light emission at a large viewing angle, thereby significantly improving the brightness uniformity, color performance and overall light emission efficiency of the display panel at a large viewing angle.

[0017] Other characteristics and advantages of the present application will become apparent from the following detailed description, or will be learned by practice of the present application.

[0018] It should be understood that the foregoing general description and the following detailed description are only exemplary and explanatory, and are not limiting to the present application. BRIEF DESCRIPTION OF DRAWINGS

[0019] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application. It is clear that the drawings described below are only some embodiments of the present application, and other drawings can be obtained according to these drawings without creative labor for those skilled in the art.

[0020] Figure 1 A preparation method flowchart of a display panel according to an embodiment of the present application is shown.

[0021] Figure 2 A structure flowchart of a display panel according to an embodiment of the present application is shown.

[0022] Figure 3 A structure diagram of a display panel according to an embodiment of the present application is shown.

[0023] Figure 4 A structure diagram of a display panel according to an embodiment of the present application is shown.

[0024] Figure 5 A preparation method flowchart of a display panel according to an embodiment of the present application is shown.

[0025] Figure 6 A structure flowchart of a display panel according to an embodiment of the present application is shown.

[0026] Figure 7 A structure diagram of a display panel according to an embodiment of the present application is shown.

[0027] Figure 8A schematic diagram of the manufacturing process of the display panel according to Embodiment 3 of this application is shown.

[0028] Figure 9 A schematic diagram of the preparation method of the three-pixel definition layer according to an embodiment of this application is shown.

[0029] Figure 10 A schematic diagram of the structure and flow of the display panel according to Embodiment 3 of this application is shown.

[0030] Figure 11 A schematic diagram of the structure of the display panel according to Embodiment 3 of this application is shown.

[0031] Figure 12 A schematic diagram of the structure and flow of the display panel according to Embodiment 4 of this application is shown.

[0032] Figure 13 A schematic diagram of the structure of the display panel according to Embodiment 4 of this application is shown.

[0033] Figure 14 A schematic flowchart of the preparation method of the display panel of Embodiment 5 of this application is shown.

[0034] Figure 15 A schematic diagram of the preparation method of the pixel definition layer in Embodiment 5 of this application is shown.

[0035] Figure 16 A schematic diagram of the structure and flow of the display panel according to Embodiment 5 of this application is shown.

[0036] Figure 17 A schematic diagram of the structure of the display panel according to Embodiment 5 of this application is shown.

[0037] Explanation of reference numerals in the attached figures:

[0038] 10. Display panel; 11. Substrate; 12. Pixel definition layer; 120. Opening; 121. Pixel definition part; 1210. First part; 1211. Second part; 1212. Transparent electrode; 13. Organic light-emitting unit; 130. Organic light-emitting layer; 131. Cathode; 14. First inorganic encapsulation layer; 15. First organic encapsulation layer; 16. Black matrix; 17. Second organic encapsulation layer; 18. Second inorganic encapsulation layer; 19. Color photoresist; 20. Conductive layer; 21. Intermediate inorganic encapsulation layer; 22. Sacrificial layer. Detailed Implementation

[0039] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided to make this application more comprehensive and complete, and to fully convey the concept of the exemplary embodiments to those skilled in the art.

[0040] In this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0041] In this application, unless otherwise expressly specified and limited, the terms "assembly," "connection," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0042] Furthermore, the described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. Numerous specific details are provided in the following description to give a thorough understanding of embodiments of this application. However, those skilled in the art will recognize that the technical solutions of this application can be practiced without one or more of the specific details, or other methods, components, apparatuses, steps, etc., can be employed. In other instances, well-known methods, apparatuses, implementations, or operations are not shown or described in detail to avoid obscuring various aspects of this application.

[0043] This application provides a method for fabricating a display panel 10 and the display panel 10 obtained using this method. Through various structural designs and fabrication processes, this application significantly shortens the vertical distance between the black matrix 16 and the organic light-emitting layer 130 in the display panel 10, thereby reducing light obstruction at wide viewing angles and improving display performance and light extraction efficiency. It should be noted that the specific details described below are intended to provide a thorough understanding and are not intended to limit the scope of protection of this application.

[0044] Example 1

[0045] See Figure 1 and Figure 2 As shown, this embodiment provides a method for integrating a black matrix 16 by preparing an encapsulation layer in steps, which includes the following steps:

[0046] Step S100a: A substrate 11 is provided, on which a pixel definition layer 12 is formed, and the pixel definition layer 12 has a plurality of openings 120.

[0047] Step S200a: Organic light-emitting unit 13 is formed within opening 120.

[0048] Step S300a: A first inorganic encapsulation layer 14 is formed on the organic light-emitting unit 13 and the pixel definition layer 12.

[0049] Step S400a: A first organic encapsulation layer 15 is formed on the first inorganic encapsulation layer 14.

[0050] In step S500a, a black matrix 16 is formed on the first organic encapsulation layer 15.

[0051] In step S600a, a second organic encapsulation layer 17 and a second inorganic encapsulation layer 18 are sequentially formed on the first organic encapsulation layer 15, with the second organic encapsulation layer 17 covering the black matrix 16.

[0052] The substrate 11 can be rigid glass or a flexible polymer material (e.g., PI). In step S100a, a driving backplane (not shown) containing a thin-film transistor (TFT) array and metal interconnects is fabricated on the substrate 11 using a mature semiconductor process. A pixel anode made of a material such as indium tin oxide (ITO) is patterned on the driving backplane. Subsequently, a pixel definition layer 12 is formed on the driving backplane and the anode by coating with an insulating material such as photosensitive polyimide or acrylic resin and undergoing exposure and development processes. The pixel definition layer 12 has a plurality of arrayed openings 120, each opening 120 precisely exposing a portion of the underlying pixel anode, thereby defining the subsequent light-emitting area. The sidewalls of the openings 120 typically have slopes, and the depth of the openings 120 is approximately 2 μm to 3 μm.

[0053] In step S200a, an organic light-emitting layer 130 and a cathode 131 are fabricated within the opening 120. For example, a hole injection layer, a hole transport layer, an organic light-emitting layer 130, an electron transport layer, and an electron injection layer are sequentially formed on the exposed anode using a vacuum evaporation process. Finally, a layer of a magnesium-silver (Mg:Ag) alloy or similar material is deposited to form a common cathode 131 covering the entire display area. This completes the fabrication of the organic light-emitting unit 13.

[0054] In step S300a, thin-film encapsulation is performed. First, a first inorganic encapsulation layer 14 is deposited on the organic light-emitting unit 13 and the pixel definition layer 12 using a plasma-enhanced chemical vapor deposition (PECVD) process. The material is silicon nitride (SiN). x It is a layer of silicon oxynitride (SiON) or silicon oxynitride (SiON), with a thickness of approximately 0.5 μm. This layer directly covers the cathode 131 and serves as the first barrier against the intrusion of water and oxygen.

[0055] In step S400a, an organic encapsulation material, such as acrylate or epoxy resin photoresist, is coated onto the first inorganic encapsulation layer 14, and then cured to form the first organic encapsulation layer 15. This step ensures that the first organic encapsulation layer 15 precisely fills the pit formed by the opening 120 of the pixel definition layer 12, forming a flat surface, typically around 3 μm thick. This flat surface is crucial for subsequent processes to reduce surface unevenness, as the thickness becomes uneven after the color photoresist 19 is coated due to its flowability.

[0056] In step S500a, a black matrix BM and color photoresists CF for red (R), green (G), and blue (B) are formed on the flat surface of the first organic encapsulation layer 15 through coating, exposure, and development processes. The black matrix 16 is made of a black resin material doped with carbon black and other light-shielding agents. It is used to block stray light from non-light-emitting areas and define pixel boundaries. Its purpose in being located between the first inorganic encapsulation layer 14 and the first organic encapsulation layer 15 is to be close to the organic light-emitting unit 13 below, thereby reducing the blocking effect of the black matrix 16 on light emission from a wide viewing angle. This significantly improves the brightness uniformity, color performance, and overall light emission efficiency of the display panel 10 at wide viewing angles.

[0057] For example, in related technologies, the black matrix 16 is disposed on the second inorganic encapsulation layer 18, and its vertical distance from the organic light-emitting unit 13 is the sum of the thickness of the first inorganic encapsulation layer 14 (0.5 μm), the thickness of the organic encapsulation layer (10 μm), and the thickness of the second inorganic encapsulation layer 18 (1 μm), which is approximately 11.5 μm. However, if the black matrix 16 is disposed between the first organic encapsulation layer 15 and the second organic encapsulation layer 17, the vertical distance from the black matrix 16 to the organic light-emitting unit 13 is the sum of the thickness of the first inorganic encapsulation layer 14 (0.5 μm) and the thickness of the first organic encapsulation layer 15 (3 μm), which is approximately 3.5 μm. This effectively reduces the distance between the black matrix 16 and the organic light-emitting unit 13, thereby effectively improving the light-shielding effect of the black matrix 16 on a wide viewing angle.

[0058] The colored photoresists 19 are made by dispersing pigments or dyes of corresponding wavelengths in photoresist. Depending on the display design, the function of the colored photoresists 19 is adjusted accordingly: when the organic light-emitting unit 13 emits white light, the red, green, and blue photoresists correspond to the sub-pixel areas below, used to convert white light into colored light; when the organic light-emitting unit 13 itself contains pixelated light-emitting layers that emit red, green, and blue light, the corresponding colored photoresists are placed above the same-color light-emitting layers, mainly used to improve color purity or reduce ambient light reflection. These photoresists, together with the black matrix 16, constitute a color filter layer.

[0059] Furthermore, as a variation of this embodiment, the colored photoresist 19 (R / G / B) can also be formed on the second inorganic encapsulation layer 18 after the second inorganic encapsulation layer 18 is fabricated; while the black matrix 16 remains in the same position on the first organic encapsulation layer 15. This design ensures that the black matrix 16 is in close contact with the light-emitting layer to optimize the viewing angle, while providing process flexibility for the integration of the color filter layer.

[0060] In step S600a, an organic encapsulation material is coated again on the color filter layer and the black matrix 16 to form a second organic encapsulation layer 17, and a second inorganic encapsulation layer 18 (such as SiN) is deposited by chemical vapor deposition. x This completes the entire thin-film encapsulation structure. The thickness of the second organic encapsulation layer 17 is approximately 10 μm, which is the sum of the thickness of the first organic encapsulation layer 15, while the second inorganic encapsulation layer 18 serves as the outermost protective layer.

[0061] See Figure 3 or Figure 4 As shown, a display panel 10 is finally obtained through the above method. The display panel 10 includes a substrate 11, a pixel definition layer 12, an organic light-emitting unit 13, a first inorganic encapsulation layer 14, a first organic encapsulation layer 15, a black matrix 16, a second organic encapsulation layer 17, and a second inorganic encapsulation layer 18. The organic light-emitting unit 13 is disposed within the opening 120 formed by the pixel definition layer 12, and the black matrix 16 is disposed between the first organic encapsulation layer 15 and the second organic encapsulation layer 17.

[0062] That is, the black matrix 16 is disposed between two organic encapsulation layers, and the thickness of the underlying medium (first inorganic encapsulation layer 14 plus first organic encapsulation layer 15) is only about 3.5 μm. Compared with the structure in related technologies where the black matrix 16 is disposed on the second inorganic encapsulation layer 18, the distance between the black matrix 16 and the organic light-emitting unit 13 is greatly shortened, effectively reducing the obstruction of large-angle light.

[0063] Example 2

[0064] Based on Embodiment 1, Embodiment 2 of this application introduces a step of thinning the pixel definition layer 12 to further reduce the distance between the black matrix 16 and the light-emitting layer.

[0065] Among them, see Figure 5 and Figure 6 As shown, after forming the first inorganic encapsulation layer 14 and before forming the first organic encapsulation layer 15, the following steps are also included:

[0066] Step S310a: The first inorganic encapsulation layer 14 is patterned to expose a portion of the pixel definition layer 12.

[0067] Step S320a: Thinning process is performed on the exposed pixel definition layer 12.

[0068] Step S330a: A conductive layer 20 is formed, which at least covers the thinned pixel definition layer 12.

[0069] Step S340a: An intermediate inorganic encapsulation layer 21 is formed on the conductive layer 20.

[0070] In step S310a, photoresist is coated on the first inorganic encapsulation layer 14, and a mask with a specific pattern is formed by exposure and development. Then, dry etching is performed to remove the parts not protected by the mask. After patterning, the first inorganic encapsulation layer 14 is only retained in the area directly above the organic light-emitting unit 13, while the top area of ​​the pixel definition layer 12 is exposed.

[0071] In step S320a, the exposed portion of the pixel definition layer 12 is thinned using an anisotropic dry etching process. This step can be performed using a plasma primarily composed of oxygen (O2) and methane (CH4). This gas combination exhibits a high etching rate for organic materials (such as the resin constituting the pixel definition layer 12), but is less effective against silicon nitride (SiN). x The etching rate of inorganic materials such as 12 is extremely low. Therefore, this etching can remove a portion of the height of the pixel definition layer 12 (e.g., reduce it by 1 μm to 1.5 μm) without damaging the organic light-emitting unit 13 protected by the remaining first inorganic encapsulation layer 14.

[0072] It should be understood that the pixel definition layer 12 needs to maintain a certain height (around 3 μm) to act as an isolation dam in the vacuum evaporation process of the organic light-emitting material. Since the evaporation source is multiple point sources, the evaporation material is diffuse, and the evaporation mask may have alignment deviations. A sufficiently high pixel definition layer 12 can effectively block the material, preventing contact or crosstalk between the light-emitting materials of adjacent pixels. Therefore, a low pixel definition layer 12 cannot be simply fabricated directly. In this application, after completing the evaporation of the organic light-emitting layer 130, the pixel definition layer 12, which has already served an isolation function, is locally thinned, thereby creating space for shortening the optical distance in the subsequent process without affecting the previous steps.

[0073] It should be noted that when etching the pixel definition layer 12, the cathode 131 may also be etched. In order to reduce the etching of the cathode 131 on the pixel definition layer 12, a conductive layer 20 is formed on the pixel definition layer 12 to connect adjacent cathodes 131.

[0074] That is, in step S330a, a conductive layer 20 is deposited on the surface of the thinned pixel definition layer 12 and the remaining first inorganic encapsulation layer 14. The material of the conductive layer 20 can be metals such as indium tin oxide (ITO) or aluminum (Al) / titanium (Ti), and the thickness is between 50 nanometers and 500 nanometers. This conductive layer 20 can serve as a common electrode line connecting the pixel cathodes 131; secondly, the conductive layer 20 can also serve as an etch stop layer in subsequent possible etching steps.

[0075] It should be noted that the pattern of the conductive layer 20 can be either covering only the area of ​​the thinned pixel definition layer 12 or covering the entire exposed surface. The specific design can be tailored to different embodiments.

[0076] In step S340a, an intermediate inorganic encapsulation layer 21 is deposited on the conductive layer 20, the material being silicon nitride (SiN). x This is used to repair the discontinuity of the packaging path that may be caused by patterned etching, ensuring packaging reliability. The subsequent steps are similar to those in Embodiment 1: a planarized first organic packaging layer 15 is coated on the intermediate inorganic packaging layer 21, followed by the sequential formation of a black matrix 16BM, red R / green G / blue B color photoresist 19CF, and the upper second organic packaging layer 17 and second inorganic packaging layer 18 (SiN). x ).

[0077] See Figure 7 As shown, a display panel 10 is finally obtained through the above method. The display panel 10 includes a substrate 11, a first pixel definition layer, a conductive layer 20, a first inorganic encapsulation layer 14, an intermediate inorganic encapsulation layer 21, a black matrix 16, an organic encapsulation layer, and a second inorganic encapsulation layer 18. The black matrix 16 is disposed on the etched and thinned pixel definition structure, achieving close-range pixel definition.

[0078] This embodiment actively thins the pixel definition layer 12, thereby further reducing the total thickness of the medium between the final black matrix 16 and the light-emitting layer, further reducing the blocking effect of the black matrix 16 on light emission from a wide viewing angle, and thus significantly improving the brightness uniformity, color performance and overall light emission efficiency of the display panel 10 at a wide viewing angle.

[0079] Example 3

[0080] This embodiment provides a solution to reduce the structural height by constructing and partially removing the composite pixel definition layer 12. First, referring to the description in Embodiment 2, the pixel definition layer 12 requires a certain height. Its main function is to effectively block adjacent pixels and prevent material crosstalk during the organic light-emitting material evaporation process. This is because the evaporation source is a point source, the evaporation material is diffuse, and the evaporation mask (FMM) may have alignment misalignment. Therefore, the distance problem cannot be simply solved by fabricating an ultra-thin pixel definition layer 12.

[0081] See Figure 8 and Figure 10 As shown, the preparation process of this embodiment three is as follows:

[0082] Step S100b: Provide a substrate 11.

[0083] In step S200b, a pixel definition layer 12 is formed on the substrate 11. The pixel definition layer 12 has a plurality of openings 120 and includes a plurality of pixel definition portions 121 arranged in an array. Each pixel definition portion 121 includes a first portion 1210, a second portion 1211 and a transparent electrode 1212 located between the first portion 1210 and the second portion 1211.

[0084] In step S300b, an organic light-emitting unit 13 is formed in the opening 120, and the cathode 131 of the organic light-emitting unit 13 is electrically connected to the transparent electrode 1212.

[0085] In step S400b, a first inorganic encapsulation layer 14 is formed on the organic light-emitting unit 13 and the pixel definition layer 12, and the first inorganic encapsulation layer 14 is patterned to expose the second part 1211 of the pixel definition part 121.

[0086] Step S500b: Etch away the exposed second portion 1211 and the cathode 131 located on the second portion 1211 until etching stops at the transparent electrode 1212.

[0087] In step S600b, an intermediate inorganic encapsulation layer 21, a black matrix 16, an organic encapsulation layer, and a second inorganic encapsulation layer 18 are sequentially formed on the transparent electrode 1212 and the first inorganic encapsulation layer 14.

[0088] See Figure 9 and Figure 10As shown, in step S100b, a driving backplate and a pixel anode are fabricated on the substrate 11. Next, in step S200b, a pixel definition layer 12 is fabricated on the substrate 11 where the driving backplate and pixel anode have been completed. This pixel definition layer 12 has multiple openings 120 and includes multiple arrayed pixel definition portions 121. Each pixel definition portion 121 includes a first portion 1210, a second portion 1211, and a transparent electrode 1212 located between the first portion 1210 and the second portion 1211. It has the following steps:

[0089] In step S210b, a first layer of pixel definition material is coated on the substrate 11 and patterned to form the first portion 1210.

[0090] In step S220b, a conductive material is coated on the first part 1210 and the substrate 11, and the conductive material is patterned to form a transparent electrode 1212.

[0091] In step S230b, a second layer of pixel definition material is coated on the substrate 11 and the transparent electrode 1212, and then patterned to form the second part 1211.

[0092] In step S210b, on the substrate 11 where the driving backplane and pixel anode have been completed, a first portion 1210 is patterned and formed through photoresist coating, exposure, and development processes. Multiple arrayed first openings (not shown in the figure) are formed, exposing the pixel anode on the underlying driving backplane, thereby defining the pixel region for the subsequent fabrication of organic light-emitting units. The thickness of this first portion 1210 is slightly greater than the total thickness of the subsequent organic light-emitting functional layer to be formed (e.g., the first portion 1210 is controlled between 0.3 μm and 1 μm), and it initially defines the substrate region of the pixel.

[0093] In step S220b, a layer of transparent conductive material (such as indium tin oxide, ITO) is deposited on the first portion 1210 and the substrate 11. A transparent electrode 1212 is then patterned on the first portion 1210 using a patterning process. The conductive material on the pixel anode is then removed to expose the pixel anode. This transparent electrode 1212 not only covers the upper surface of the first portion 1210 but also extends to cover a portion of its sidewalls. This design allows the transparent electrode 1212 to form a reliable electrical contact with the cathode 131 of the organic light-emitting diode device in subsequent processes, while its material properties (such as indium tin oxide) also serve as an effective etch stop layer in subsequent etching processes.

[0094] In step S230b, an insulating material is coated on the transparent electrode 1212 and the area of ​​the substrate 11 not covered by it. Then, a second portion 1211 is patterned on the transparent electrode 1212 using photolithography, forming multiple arrayed second openings (not shown in the figure). These second openings expose the lower first opening and the pixel anode on the driving backplane, thus defining the pixel region for the subsequent fabrication of the organic light-emitting unit. The material of the second portion 1211 can be the same as that of the lower first portion 1210, and the total thickness of the two combined reaches the conventional height (approximately 3 μm) required for effective isolation between pixels. This constitutes a composite pixel definition structure consisting of the first portion 1210, the transparent electrode 1212, and the second portion 1211.

[0095] In step S300b, an organic light-emitting layer 130 and a cathode 131 are subsequently prepared within these openings 120 using a vacuum evaporation process. For example, a hole injection layer, a hole transport layer, an organic light-emitting layer 130, an electron transport layer, and an electron injection layer are sequentially evaporated. Subsequently, a thin layer of magnesium-silver (Mg:Ag) alloy, approximately 10 nm to 20 nm thick, is deposited as the cathode 131. An organic material, approximately 100 nm thick, is then deposited on this cathode 131 as a protective layer. During the evaporation process, the cathode 131 directly contacts the transparent electrode 1212 (ITO) portion on the sidewall of the first portion 1210 that is not completely covered by the second portion 1211, thereby achieving electrical connection.

[0096] After the organic light-emitting unit is fabricated, subsequent patterning and etching steps are performed. It should be noted that the very thin cathode 131 and the organic cathode 131 protective layer will be rapidly removed or etched in the subsequent dry etching environment (such as oxygen plasma).

[0097] In step S400b, after the organic light-emitting unit 13 is fabricated, an etching protective layer is deposited on the cathode 131 protective layer and the entire structural surface using a chemical vapor deposition process. The material of the etching protective layer is silicon nitride (SiN). x The thickness is approximately 0.1 nm to 500 nm. The key function of this etch protective layer is to protect the underlying organic light-emitting functional layer from damage during subsequent dry etching processes, and to protect the junction between the cathode 131 and the transparent electrode 1212 located in the sidewall region of the first part 1210, ensuring the reliability of the electrical connection.

[0098] Next, the first inorganic encapsulation layer 14 (SiN) was applied. x The graph is then visualized to reveal a portion of the second section 1211 above.

[0099] In step S500b, dry etching is performed using the patterned first inorganic encapsulation layer 14 and the etch protection layer as a composite hard mask. This etching process is anisotropic. Since the cathode 131 and the cathode 131 protective layer are vapor-deposited onto the surface of the second portion 1211, when the etching completely removes the exposed second portion 1211, the cathode 131 protective layer and the cathode 131, which were originally located above the second portion 1211, will also be removed along with it. The etching continues downward, and when it reaches the surface of the lower transparent electrode 1212 (ITO), the etching rate will drop sharply or stop due to the extremely high selectivity of the etching gas for ITO, thus achieving self-stopping etching.

[0100] During this process, the etching protective layer (SiN) located on the side and above the transparent electrode 1212 x Due to its inorganic properties, it also exhibits high tolerance in this etching environment, and can work together with the first inorganic encapsulation layer 14 to mask and protect the underlying critical structure. This process removes the second portion 1211 within the patterned area and the cathode 131 material above it, ultimately retaining the underlying first portion 1210, the transparent electrode 1212, and the main structure of the organic light-emitting unit 13 covered by the etched protective layer and the remaining first inorganic layer.

[0101] In step S600b, an intermediate inorganic encapsulation layer 21 (SiN) is deposited on the exposed transparent electrode 1212 and the remaining first inorganic encapsulation layer 14. x Then, a black matrix 16BM, an organic encapsulation layer, and a second inorganic encapsulation layer 18 (SiN) are formed sequentially. x ).

[0102] This embodiment constructs a composite structure of a first part 1210, a transparent electrode 1212, and a second part 1211, and utilizes the transparent electrode 1212 as an etch stop layer to effectively remove the second part 1211, achieving a significant reduction in the height of the pixel definition area. Subsequently, an intermediate inorganic encapsulation layer 21 is directly deposited on the exposed transparent electrode 1212 and the first inorganic encapsulation layer 14 to prepare a black matrix 16. Therefore, the black matrix 16 is ultimately disposed on the intermediate inorganic encapsulation layer 21, and the vertical spacing between it and the underlying organic light-emitting unit 13 is mainly determined by the thickness of the retained first part 1210, the thickness of the transparent electrode 1212 layer, and the thickness of the intermediate inorganic encapsulation layer 21. Compared with related technologies, this substantially reduces the total thickness of the unnecessary dielectric material below the black matrix 16, further reducing the occlusion effect of the black matrix 16 on light emission from a wide viewing angle, thereby significantly improving the brightness uniformity, color performance, and overall light emission efficiency of the display panel 10 at wide viewing angles.

[0103] See Figure 11As shown, a display panel 10 is finally obtained through the above method. The display panel 10 includes a substrate 11, a first pixel definition layer, a transparent electrode 1212, a first inorganic encapsulation layer 14, an intermediate inorganic encapsulation layer 21, a black matrix 16, an organic encapsulation layer, and a second inorganic encapsulation layer 18. The black matrix 16 is disposed on the etched and thinned pixel definition structure (first part 1210 + transparent electrode 1212), shortening the distance between the black matrix 16 and the organic light-emitting layer 130, reducing the blocking effect of the black matrix 16 on light emission from a wide viewing angle, thereby significantly improving the brightness uniformity, color performance, and overall light emission efficiency of the display panel 10 at wide viewing angles.

[0104] Example 4

[0105] This embodiment is a variation of Embodiment 3. Its main difference is that the black matrix 16 is prepared earlier and integrated into a lower layer of the composite pixel definition structure.

[0106] See Figure 12 As shown, the specific steps are as follows: After forming the first portion 1210, a black matrix 16BM is directly fabricated on it. The pattern of the black matrix 16 is consistent with the final design. Subsequently, a conductive material (such as indium tin oxide, ITO) is deposited and patterned on the black matrix 16 and the area of ​​the first portion 1210 not covered by the black matrix 16 to form a transparent electrode 1212. This transparent electrode 1212 covers and contacts the black matrix 16.

[0107] The subsequent process is similar to that in Example 3: a second portion 1211 is formed on the transparent electrode 1212; an organic light-emitting unit 13 is fabricated within the first and second openings, with its cathode 131 connected to the transparent electrode 1212; the second portion 1211 is patterned and etched away, with the etching stopping at the transparent electrode 1212; finally, an intermediate inorganic encapsulation layer 21 (SiN) is sequentially deposited. x ), upper organic encapsulation layer and second inorganic encapsulation layer 18 (SiN) x ).

[0108] In this final structure, the black matrix 16 is embedded between the first part 1210 and the transparent electrode 1212. Its position is closer to the substrate 11 than in Embodiment 3. The vertical distance between the black matrix 16 and the light-emitting layer in the organic light-emitting unit 13 is also further optimized, which further reduces the blocking effect of the black matrix 16 on the light emission from a wide viewing angle, thereby significantly improving the brightness uniformity, color performance and overall light emission efficiency of the display panel 10 at a wide viewing angle.

[0109] See Figure 13As shown, a display panel 10 is finally obtained through the above method. The display panel 10 includes a substrate 11, a first pixel definition layer, a black matrix 16, a transparent electrode 1212, a first inorganic encapsulation layer 14, an intermediate inorganic encapsulation layer 21, an organic encapsulation layer, and a second inorganic encapsulation layer 18. In this structure, the black matrix 16 is integrated between the first portion 1210 and the transparent electrode 1212, making the black matrix 16 closer to the organic light-emitting layer 130, further reducing the blocking effect of the black matrix 16 on light emission from a wide viewing angle, thereby significantly improving the brightness uniformity, color performance, and overall light emission efficiency of the display panel 10 at a wide viewing angle.

[0110] Example 5

[0111] This embodiment provides a process solution based on physical stripping rather than chemical etching, the core of which is the introduction of a sacrificial layer 22. See also Figure 14 As shown, it includes the following steps:

[0112] Step S100c: Provide a substrate 11.

[0113] In step S200c, a pixel definition layer 12 is formed on the substrate 11. The pixel definition layer 12 has a plurality of openings 120 and includes a plurality of pixel definition portions 121 arranged in an array. Each pixel definition portion 121 includes a first portion 1210, a second portion 1211, a sacrificial layer 22 and a black matrix 16 located between the first portion 1210 and the second portion 1211. The black matrix 16 is located on the side of the sacrificial layer 22 closer to the first portion 1210.

[0114] Step S300c: Remove the sacrificial layer 22, decompose the sacrificial layer 22 and remove the second part 1211, thereby exposing the black matrix 16 and the first part 1210.

[0115] In step S400c, an organic light-emitting unit 13 is formed on the exposed black matrix 16 and the first portion 1210, and within the opening 120.

[0116] In step S500c, a thin film encapsulation layer is formed on the organic light-emitting unit 13.

[0117] See Figure 15 and Figure 16 As shown, in step S200c, on the substrate 11 where the driving backplane and pixel anode have been completed, the following steps are performed sequentially:

[0118] In step S210c, a first layer of pixel definition material is coated on the substrate 11 and patterned to form the first portion 1210.

[0119] In step S220c, a black light-shielding material is coated on the first part 1210 and the substrate 11, and then patterned to form a black matrix 16.

[0120] Step S230c: Deposit a sacrificial layer 22 on the black matrix 16.

[0121] In step S240c, a second layer of pixel definition material is coated on the sacrificial layer 22 and the substrate 11, and then patterned to form the second part 1211.

[0122] In step S210c, a first layer of pixel definition material (such as photoresist) is coated on the substrate 11, and patterned by exposure and development processes to form a first portion 1210 with multiple first openings. These first openings expose the pixel anode on the underlying drive backplane.

[0123] In step S220c, a black light-blocking material is coated on the first portion 1210 and the area exposed by the first opening, and patterned by an exposure and development process to form a black matrix 16BM. The pattern of the black matrix 16 defines the non-light-emitting area.

[0124] In step S230c, a sacrificial layer 22 is deposited on the black matrix 16 and the areas not covered by it. The material is gallium nitride (GaN), and the thickness is approximately 0.1 nm to 100 nm. Gallium nitride (GaN) is characterized by photodecomposition when irradiated with ultraviolet laser of a specific wavelength (e.g., 266 nm or 312 nm), rapidly decomposing into elemental gallium (Ga) and nitrogen gas (N2).

[0125] It should be noted that the sacrificial layer 22 completely encloses the top and sidewalls of the black matrix 16, forming a continuous sacrificial layer 22 structure. The design of the sacrificial layer 22 completely enclosing the black matrix 16 ensures the uniformity of energy absorption and gas generation during subsequent laser irradiation, which is the key to achieving clean and complete stripping of the second part 1211.

[0126] In step S240c, a second pixel definition material is coated on the sacrificial layer 22 that completely encapsulates the black matrix 16. This material is then patterned using exposure and development processes to form a second portion 1211 with multiple second openings. The positions of these second openings strictly correspond to the positions of the first opening and the openings of the black matrix 16, collectively exposing the underlying pixel anode. Thus, a composite pixel definition structure consisting of the first portion 1210, the black matrix 16, the sacrificial layer 22, and the second portion 1211 is fabricated.

[0127] After completing the aforementioned composite pixel definition structure, laser irradiation is applied from above the panel. The laser beam penetrates the upper second portion 1211 and is absorbed by the gallium nitride (GaN) sacrificial layer 22 sandwiched in the middle. Upon absorbing the laser energy, the sacrificial layer 22 instantly decomposes, generating a large amount of nitrogen gas (N2). The nitrogen gas rapidly expands between the two pixel definition layers 12, generating sufficient pressure to blow away the upper second portion 1211 entirely or to peel it off from the lower layer.

[0128] It should be noted that, in order to effectively remove the second part 1211 that has been peeled off, nitrogen (N2) gas can be introduced into the process chamber during or after laser irradiation, using the airflow to carry away the fragments. Alternatively, the panel can be placed vertically, allowing it to detach under gravity. This peeling process is a purely dry physical process, without involving any wet chemical reagents or plasma etching, therefore eliminating the need for an additional protective layer, making the process simpler and more reliable.

[0129] After peeling, the black matrix 16BM and the first portion 1210 are exposed, forming a pixel definition section 121 with significantly reduced height. Finally, an organic light-emitting unit 13 is fabricated within the opening 120, and a thin-film encapsulation layer (such as a first inorganic encapsulation layer 14 / organic encapsulation layer / second inorganic encapsulation layer 18) is deposited on the organic light-emitting unit 13, resulting in a display panel 10 structure where the black matrix 16 is extremely close to the light-emitting layer. This further reduces the blocking effect of the black matrix 16 on light emission from a wide viewing angle, thereby significantly improving the brightness uniformity, color performance, and overall light emission efficiency of the display panel 10 at wide viewing angles.

[0130] See Figure 17 As shown, a display panel 10 is finally obtained through the above method. The display panel 10 includes a substrate 11, a first portion 1210, a black matrix 16, an organic light-emitting unit 13, and a thin film encapsulation layer covering the organic light-emitting unit 13. This structure removes the upper second portion 1211 through a laser lift-off process, so that the black matrix 16 is directly located on the retained first portion 1210. The structure is extremely simple and the distance between the black matrix 16 and the light-emitting layer is minimized, thereby significantly improving the brightness uniformity, color performance, and overall light extraction efficiency of the display panel 10 at wide viewing angles.

[0131] In the description of this specification, references to terms such as "some embodiments," "exemplarily," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. The illustrative expressions of the above terms in this specification do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0132] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application. Therefore, any changes or modifications made in accordance with the claims and description of this application should fall within the scope of this patent application.

Claims

1. A method for manufacturing a display panel, characterized in that, Includes the following steps: A substrate is provided, on which a pixel definition layer is formed, the pixel definition layer having a plurality of openings; An organic light-emitting unit is formed within the opening; A first inorganic encapsulation layer is formed on the organic light-emitting unit and the pixel definition layer; The first inorganic encapsulation layer is patterned to expose a portion of the pixel definition layer, and the exposed pixel definition layer is thinned. A first organic encapsulation layer is formed on the first inorganic encapsulation layer; A black matrix is ​​formed on the first organic encapsulation layer; A second organic encapsulation layer and a second inorganic encapsulation layer are sequentially formed on the first organic encapsulation layer, with the second organic encapsulation layer covering the black matrix.

2. The method according to claim 1, characterized in that, During or after the step of forming the black matrix, the method further includes the step of forming a plurality of colored photoresists on the first organic encapsulation layer, wherein the black matrix and the colored photoresists constitute a color filter layer.

3. The preparation method according to claim 1, characterized in that, After forming the first inorganic encapsulation layer and before forming the first organic encapsulation layer, the method further includes the following steps: A conductive layer is formed, which at least covers the thinned pixel definition layer; An intermediate inorganic encapsulation layer is formed on the conductive layer.

4. A method for manufacturing a display panel, characterized in that, Includes the following steps: Provide a substrate; A pixel definition layer is formed on the substrate. The pixel definition layer has multiple openings and includes multiple pixel definition portions arranged in an array. Each pixel definition portion includes a first portion, a second portion, and a transparent electrode located between the first portion and the second portion. An organic light-emitting unit is formed within the opening, and the cathode of the organic light-emitting unit is electrically connected to the transparent electrode; A first inorganic encapsulation layer is formed on the organic light-emitting unit and the pixel definition layer, and the first inorganic encapsulation layer is patterned to expose a second part of the pixel definition portion; Etching removes the exposed second portion and the cathode located on the second portion until etching stops at the transparent electrode; On the transparent electrode and the first inorganic encapsulation layer, there are sequentially intermediate inorganic encapsulation layers, black matrix, organic encapsulation layers and second inorganic encapsulation layers.

5. A method for manufacturing a display panel, characterized in that, Includes the following steps: Provide a substrate; A pixel definition layer is formed on the substrate. The pixel definition layer has multiple openings and includes multiple pixel definition portions arranged in an array. Each pixel definition portion includes a first portion, a second portion, and a transparent electrode and a black matrix located between the first portion and the second portion. The black matrix is ​​disposed on the side of the transparent electrode close to the first portion. An organic light-emitting unit is formed within the opening, and the cathode of the organic light-emitting unit is electrically connected to the transparent electrode; A first inorganic encapsulation layer is formed on the organic light-emitting unit and the pixel definition layer, and the first inorganic encapsulation layer is patterned to expose a second part of the pixel definition portion; Etching removes the exposed second portion and the cathode located on the second portion until etching stops at the transparent electrode; An intermediate inorganic encapsulation layer, an organic encapsulation layer, and a second inorganic encapsulation layer are sequentially formed on the transparent electrode and the first inorganic encapsulation layer.

6. A method for manufacturing a display panel, characterized in that, Includes the following steps: Provide a substrate; A pixel definition layer is formed on the substrate. The pixel definition layer has multiple openings and includes multiple pixel definition portions arranged in an array. The step of forming each pixel definition portion includes: forming a first portion on the substrate; forming a black matrix on the first portion; forming a sacrificial layer on the black matrix and the area not covered thereunder, the sacrificial layer completely covering the top and sidewalls of the black matrix; and forming a second portion on the sacrificial layer. Remove the sacrificial layer, decompose the sacrificial layer and remove the second part, thereby exposing the black matrix and the first part; Organic light-emitting units are formed on the exposed black matrix and the first portion, and within the opening; A thin film encapsulation layer is formed on the organic light-emitting unit.

7. A display panel, characterized in that, include: Substrate; A pixel definition layer and an organic light-emitting unit are disposed on the substrate, wherein the pixel definition layer has a thinning structure in the region corresponding to the black matrix; A first inorganic encapsulation layer covering the organic light-emitting unit; A first organic encapsulation layer disposed on the first inorganic encapsulation layer; The black matrix is ​​set on the first organic encapsulation layer; as well as A second organic encapsulation layer and a second inorganic encapsulation layer are sequentially formed on the first organic encapsulation layer, with the second organic encapsulation layer covering the black matrix.

8. The display panel according to claim 7, characterized in that, Between the first inorganic encapsulation layer and the first organic encapsulation layer, a conductive layer and an intermediate inorganic encapsulation layer are sequentially provided. The conductive layer at least covers the pixel definition layer with the thinned structure, and the intermediate inorganic encapsulation layer covers the conductive layer.

9. A display panel, characterized in that, include: Substrate; A pixel definition layer is disposed on the substrate, the pixel definition layer having a plurality of openings and including a plurality of pixel definition portions arranged in an array, the pixel definition portion including a first portion and a transparent electrode, the transparent electrode covering the upper surface of the first portion and extending to its sidewall; A black matrix is ​​disposed on the side of the transparent electrode away from the first part, or on the side of the transparent electrode close to the first part; An organic light-emitting unit is disposed within the opening, and the cathode of the organic light-emitting unit is electrically connected to the transparent electrode at the sidewall of the first part; A first inorganic encapsulation layer is disposed within the opening and covers the organic light-emitting unit; An intermediate inorganic encapsulation layer covers the transparent electrode and the first inorganic encapsulation layer; An organic encapsulation layer and a second inorganic encapsulation layer covering the intermediate inorganic encapsulation layer.

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