Display substrate, manufacturing method thereof and display device
By using a wet etching process to prepare the partition structure of the conductive isolation layer in the production of large-size flexible OLED screens, the problems of uneven film formation and poor color mixing caused by gravity sagging are solved, achieving efficient production and cost reduction.
Patent Information
- Application Number
- CN202510905474.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-01
- Publication Date
- 2025-10-03
AI Technical Summary
Existing technologies face problems of uneven film formation and poor color mixing due to gravity sagging in the production of large-size flexible OLED screens, and the existing horizontal thermal evaporation coating method is difficult to mass-produce, resulting in high production costs.
A wet etching process is used to prepare the partition structure of the conductive isolation layer one by one on the pixel definition layer of the organic material. The high selectivity of wet etching is used to avoid etching damage to the anode, and the conductive isolation layer is used as an etching barrier layer to simplify the process flow and improve the pixel aperture ratio.
The pixel aperture ratio is improved, the screen display power consumption is reduced, the service life is extended, and the manufacturing cost is reduced, while foreign matter residue and cathode connection failure caused by poor dry etching are avoided.
Smart Images
Figure CN120751885A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to the field of display technology, and in particular to a display substrate, a manufacturing method thereof, and a display device. Background Art
[0002] As flexible OLED screens gain popularity in the end market, mid-sized foldable screens in particular are experiencing explosive growth, reaching an average annual compound growth rate of 80%. As screen sizes increase, the efficiency and cost-effectiveness of cutting using existing AMOLED mass production lines (G6H, 1500×925mm) will inevitably lead to high product prices, making it difficult to mass-produce and capture the market. The glass substrate size of larger generation lines will help improve panel cutting efficiency, thereby reducing production costs. However, as substrate size increases, the existing horizontal thermal evaporation (VTE) coating method will face significant challenges. In particular, shadows caused by gravity sagging during the use of fine metal masks (FMMs) will increase, leading to problems such as uneven film formation and poor color mixing. Summary of the Invention
[0003] The display substrate, the manufacturing method thereof, and the display device provided by the embodiments of the present disclosure are specifically described as follows:
[0004] In one aspect, an embodiment of the present disclosure provides a display substrate, comprising:
[0005] substrate;
[0006] an anode, located on one side of the substrate;
[0007] A pixel definition layer, which is a single layer of organic material. The pixel definition layer includes a pixel opening. The orthographic projection of the pixel opening on the base substrate overlaps with the orthographic projection of the anode on the base substrate. The pixel opening includes a first pixel opening and a second pixel opening.
[0008] a conductive isolation layer, comprising a first partition structure surrounding the first pixel opening and a second partition structure surrounding the second pixel opening, wherein the first partition structure and the second partition structure are integrally arranged between adjacent first pixel openings and second pixel openings;
[0009] a light-emitting functional layer, comprising a first color light-emitting functional layer and a second color light-emitting functional layer, wherein the first color light-emitting functional layer is disposed on the anode at the first pixel opening, and the second color light-emitting functional layer is disposed on the anode at the second pixel opening;
[0010] The cathode includes a first cathode and a second cathode, wherein the first cathode is arranged on the first color luminescent functional layer and contacts the side wall of the first partition structure, and the second cathode is arranged on the second color luminescent functional layer and contacts the side wall of the second partition structure.
[0011] In some embodiments, the above-mentioned display substrate provided in the embodiments of the present disclosure further includes a grid structure located on the side of the conductive isolation layer away from the base substrate, the grid structure covers the conductive isolation layer and does not overlap with the pixel opening; the grid structure and the conductive isolation layer between adjacent pixel openings constitute a bottom cut structure.
[0012] In some embodiments, in the above-mentioned display substrate provided by the embodiments of the present disclosure, the pixel opening further includes a third pixel opening;
[0013] The conductive isolation layer further includes a third partition structure surrounding the third pixel opening, wherein the first partition structure and the third partition structure between the adjacent first pixel opening and the third pixel opening are integrally arranged, and the second partition structure and the third partition structure between the adjacent second pixel opening and the third pixel opening are integrally arranged;
[0014] The light-emitting functional layer further includes a third color light-emitting functional layer, and the third color light-emitting functional layer is provided on the anode at the third pixel opening;
[0015] The cathode further includes a third cathode, which is disposed on the third color light-emitting functional layer and contacts the sidewall of the third partition structure.
[0016] In some embodiments, the above-mentioned display substrate provided in the embodiments of the present disclosure further includes the first encapsulation layer covering the first pixel opening and the first partition structure, the second encapsulation layer covering the second pixel opening and the second partition structure, the third encapsulation layer covering the third pixel opening and the third partition structure, and a fourth encapsulation layer covering the first encapsulation layer, the second encapsulation layer and the third encapsulation layer.
[0017] In some embodiments, in the above-mentioned display substrate provided by the embodiments of the present disclosure, the light-emitting functional layer includes a hole injection layer, a hole transport layer, an optical adjustment layer, a light-emitting material layer, an electron transport layer and an electron injection layer.
[0018] In some embodiments, in the above-mentioned display substrate provided in the embodiments of the present disclosure, the light-emitting functional layer includes a hole injection layer, a first hole transport layer, a first optical adjustment layer, a first light-emitting material layer, a first electron transport layer, a charge generation layer, a second hole transport layer, a second optical adjustment layer, a second light-emitting material layer, a second electron transport layer and an electron injection layer.
[0019] On the other hand, an embodiment of the present disclosure provides a method for manufacturing the above-mentioned display substrate, comprising:
[0020] providing a substrate;
[0021] forming an anode on the base substrate;
[0022] forming a pixel definition layer on the layer where the anode is located, the pixel definition layer including a pixel opening, the orthographic projection of the pixel opening on the base substrate overlapping with the orthographic projection of the anode on the base substrate, and the pixel opening including a first pixel opening and a second pixel opening;
[0023] depositing a conductive isolation layer on the pixel definition layer;
[0024] Using a wet etching process to etch away the conductive isolation layer at the first pixel opening to form a first partition structure surrounding the first pixel opening;
[0025] Depositing a first color light-emitting functional layer and a first cathode on the conductive isolation layer;
[0026] Using the conductive isolation layer as an etching barrier, dry-etching the first cathode and the first color light-emitting functional layer to retain the first color light-emitting functional layer and the first cathode on the first pixel opening and the first partition structure;
[0027] Using a wet etching process to etch away the conductive isolation layer at the second pixel opening to form a second partition structure surrounding the second pixel opening, wherein the first partition structure and the second partition structure between adjacent first pixel openings are integrally arranged;
[0028] Depositing a second color light-emitting functional layer and a second cathode on the conductive isolation layer;
[0029] The second cathode and the second color light-emitting functional layer are dry-etched to retain the second color light-emitting functional layer and the second cathode on the second pixel opening and the second partition structure.
[0030] In some embodiments, in the above-mentioned manufacturing method provided in the embodiment of the present disclosure, after depositing a conductive isolation layer on the pixel definition layer and before forming a first partition structure surrounding the first pixel opening, the method further includes:
[0031] A cap layer is deposited on the conductive isolation layer, and the conductive isolation layer is used as an etching barrier layer. The cap layer is dry-etched to form a grid structure, and the orthographic projection of the grid structure on the base substrate does not overlap with the orthographic projection of the pixel opening on the base substrate.
[0032] In some embodiments, in the above-mentioned manufacturing method provided in the embodiments of the present disclosure, forming a pixel definition layer on the layer where the anode is located specifically includes:
[0033] A single organic material layer is deposited on the layer where the anode is located, and the organic material layer is sequentially exposed, developed and post-baked to form a pixel definition layer.
[0034] In some embodiments, in the above-mentioned manufacturing method provided in the embodiment of the present disclosure, after depositing the first color light-emitting functional layer and the first cathode on the conductive isolation layer, and before dry-etching the first cathode and the first color light-emitting functional layer using the isolation layer as an etching barrier layer to retain the first color light-emitting functional layer and the first cathode on the first pixel opening and the first partition structure, the method further includes:
[0035] A first encapsulation layer is deposited on the first cathode, and the first encapsulation layer is etched to retain the first pixel opening and the first partition structure.
[0036] In some embodiments, in the above-mentioned manufacturing method provided in the embodiment of the present disclosure, after depositing the second color light-emitting functional layer and the second cathode on the conductive isolation layer, and before dry-etching the second cathode and the second color light-emitting functional layer to retain the second color light-emitting functional layer and the second cathode on the second pixel opening and the second partition structure, the method further includes:
[0037] A second encapsulation layer is deposited on the second cathode, and the second encapsulation layer is etched to retain the second pixel opening and the second partition structure.
[0038] In some embodiments, in the above-mentioned manufacturing method provided in the embodiment of the present disclosure, the pixel opening further includes a third pixel opening, and after dry etching the second cathode and the second color light-emitting functional layer to retain the second pixel opening and the second color light-emitting functional layer and the second cathode on the second partition structure, the method further includes:
[0039] Using a wet etching process to etch away the conductive isolation layer at the third pixel opening to form a third partition structure surrounding the third pixel opening, wherein the first partition structure and the third partition structure are integrally arranged between adjacent first pixel openings and third pixel openings, and the second partition structure and the third partition structure are integrally arranged between adjacent second pixel openings and third pixel openings;
[0040] depositing a third color light-emitting functional layer and a third cathode on the conductive isolation layer;
[0041] The third cathode and the third color light-emitting functional layer are dry-etched to retain the third color light-emitting functional layer and the third cathode on the third pixel opening and the third partition structure.
[0042] In some embodiments, in the above-mentioned manufacturing method provided in the embodiment of the present disclosure, after depositing the third color light-emitting functional layer and the third cathode on the conductive isolation layer, and before dry-etching the third cathode and the third color light-emitting functional layer to retain the third pixel opening and the third color light-emitting functional layer and the third cathode on the third partition structure, the method further includes:
[0043] A third encapsulation layer is deposited on the third cathode, and the third encapsulation layer is etched to retain the third pixel opening and the third partition structure.
[0044] In some embodiments, in the above-mentioned manufacturing method provided in the embodiment of the present disclosure, the second cathode and the second color light-emitting functional layer are dry-etched, including: using the conductive isolation layer as an etching barrier layer, dry-etching and removing the second cathode and the second color light-emitting functional layer of the third pixel opening.
[0045] In some embodiments, in the above-mentioned manufacturing method provided in the embodiments of the present disclosure, depositing any one of the first cathode, the second cathode, and the third cathode specifically includes:
[0046] A metal layer is formed by vacuum evaporation process, and a transparent oxide conductive layer is formed on the metal layer by sputtering process. The metal layer and the transparent oxide conductive layer constitute any one of the first cathode, the second cathode and the third cathode.
[0047] On the other hand, an embodiment of the present disclosure provides a display device, including the above-mentioned display substrate provided by an embodiment of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS
[0048] Figure 1 A schematic structural diagram of a display substrate in related art;
[0049] Figure 2 A schematic structural diagram of a display substrate provided in an embodiment of the present disclosure;
[0050] Figure 3 For the Figure 2 Schematic diagram of the cross-sectional structure of the I-I' line;
[0051] Figure 4 A schematic structural diagram of a light-emitting device provided in an embodiment of the present disclosure;
[0052] Figure 5 A schematic diagram of another structure of a light emitting device provided in an embodiment of the present disclosure;
[0053] Figure 6 for Figure 3 The figure shows a schematic diagram of the structure of a display substrate during the manufacturing process;
[0054] Figure 7 for Figure 3 The diagram shows another structural diagram of a display substrate during the manufacturing process;
[0055] Figure 8 for Figure 3 The diagram shows another structural diagram of a display substrate during the manufacturing process;
[0056] Figure 9 for Figure 3 The diagram shows another structural diagram of a display substrate during the manufacturing process;
[0057] Figure 10 for Figure 3 The diagram shows another structural diagram of a display substrate during the manufacturing process;
[0058] Figure 11 for Figure 3 The diagram shows another structural diagram of a display substrate during the manufacturing process;
[0059] Figure 12 for Figure 3 The diagram shows another structural diagram of a display substrate during the manufacturing process;
[0060] Figure 13 for Figure 3 The diagram shows another structural diagram of a display substrate during the manufacturing process;
[0061] Figure 14 for Figure 3 The diagram shows another structural diagram of a display substrate during the manufacturing process;
[0062] Figure 15 for Figure 3 The diagram shows another structural diagram of a display substrate during the manufacturing process;
[0063] Figure 16 for Figure 3 The diagram shows another structural diagram of a display substrate during the manufacturing process;
[0064] Figure 17 for Figure 3 The diagram shows another structural diagram of a display substrate during the manufacturing process;
[0065] Figure 18 for Figure 3 The diagram shows another structural diagram of a display substrate during the manufacturing process;
[0066] Figure 19 for Figure 3 The diagram shows another structural diagram of a display substrate during the manufacturing process;
[0067] Figure 20 for Figure 3 The diagram shows another structural diagram of a display substrate during the manufacturing process;
[0068] Figure 21 for Figure 3 The diagram shows another structural diagram of a display substrate during the manufacturing process;
[0069] Figure 22 for Figure 3 The diagram shows another structural diagram of a display substrate during the manufacturing process;
[0070] Figure 23 for Figure 3 The diagram shows another structural diagram of a display substrate during the manufacturing process;
[0071] Figure 24 A schematic diagram of the partition structure provided in an embodiment of the present disclosure leading to patterned evaporation film formation. DETAILED DESCRIPTION
[0072] To further clarify the objectives, technical solutions, and advantages of the embodiments of the present disclosure, the technical solutions of the embodiments of the present disclosure will be described clearly and completely below in conjunction with the accompanying drawings of the embodiments of the present disclosure. It should be noted that in the drawings, the thicknesses of layers, films, panels, regions, etc. are exaggerated for clarity. In this disclosure, exemplary embodiments are described with reference to cross-sectional views that are schematic representations of idealized embodiments. As such, deviations from the shapes shown in the drawings are to be expected, for example, as a result of manufacturing techniques and / or tolerances. Therefore, the embodiments described in this disclosure should not be construed as limited to the specific shapes of the regions shown in this disclosure, but rather include deviations in shape resulting from, for example, manufacturing. For example, a region illustrated or described as flat may typically have rough and / or nonlinear features; a sharp angle illustrated may be rounded, etc. Therefore, the regions shown in the drawings are schematic in nature, and their sizes and shapes are not intended to illustrate the precise shapes of the regions or reflect true scale, but are intended solely to illustrate the present disclosure. Throughout, identical or similar reference numerals denote identical or similar elements or elements having identical or similar functions. In order to keep the following description of the embodiments of the present disclosure clear and concise, the present disclosure omits detailed descriptions of known functions and known components.
[0073] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning understood by persons of ordinary skill in the field to which the present disclosure belongs. The words "first", "second" and similar terms used in the present disclosure and the claims do not indicate any order, quantity or importance, but are only used to distinguish different components. Words such as "include" or "comprise" mean that the elements or objects preceding the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Inside", "outside", "upper", "lower" and the like are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.
[0074] In the following description, when an element or layer is referred to as being “on” or “connected to” another element or layer, the element or layer may be directly on, directly connected to, the other element or layer, or there may be intermediate elements or intermediate layers. When an element or layer is referred to as being “disposed on one side of” another element or layer, the element or layer may be directly on, directly connected to, the other element or layer, or there may be intermediate elements or intermediate layers. However, when an element or layer is referred to as being “directly on” or “directly connected to” another element or layer, there are no intermediate elements or intermediate layers. The term “and / or” includes any and all combinations of one or more of the associated listed items.
[0075] In some embodiments, full-color OLED devices can be prepared based on photolithography, which can have advantages such as increasing pixel aperture ratio, increasing screen brightness, reducing screen display power consumption, extending service life, and reducing manufacturing costs.
[0076] Figure 1 The related display substrate prepared by photolithography is shown. Figure 1 All the partition structures D are formed at one time, which may easily lead to failure of the cathode connection partition structure D of the final device, resulting in a low yield of the final device; using the inorganic pixel definition layer PDL2 as a protective layer for the organic pixel definition layer PDL1 can avoid damage to the organic pixel definition layer PDL1 during the etching and patterning process of the OLED device, but will reduce the effective aperture ratio of the pixel and increase the difficulty of the backplane process, especially the etching and patterning process of the inorganic pixel definition layer PDL2 (exposing the anode A), which will use over-etching time to avoid material residue of the inorganic pixel definition layer PDL2, which will damage the anode A and cause the device efficiency and life to decline.
[0077] In order to improve the above technical problems, the present disclosure provides a display substrate. Figure 3 A schematic diagram of the structure of the display substrate is given. Figure 4 For the Figure 3 The cross-sectional view of the I-I' line. Figure 3 and Figure 4As shown, the display substrate provided by the embodiment of the present disclosure may include: a base substrate 101, a pixel driving circuit layer 102, a flat layer 103, an anode 104, a pixel definition layer 105, a conductive isolation layer 106, a light-emitting functional layer 107 and a cathode 108. Among them, the anode 104 is located on one side of the base substrate 101, and the anode 104 may include a first indium tin oxide layer, a silver metal layer and a second indium tin oxide layer (ITO / Ag / ITO) arranged in a stacked manner; the pixel definition layer 105 is a single layer of organic material layer, and the pixel definition layer 105 includes a pixel opening K, and the orthographic projection of the pixel opening K on the base substrate 101 overlaps with the orthographic projection of the anode 104 on the base substrate 101, and the pixel opening K includes a first pixel opening R and a second pixel opening G; the conductive isolation layer 106 may be a metal layer (for example, a molybdenum metal layer), and the conductive isolation layer 106 may include a first partition structure D1 surrounding the first pixel opening R, and a second partition structure D2 surrounding the second pixel opening G, and the adjacent first pixel opening R and the second pixel opening The first partition structure D1 and the second partition structure D2 between the openings G are integrally arranged, that is, the conductive isolation layer 106 is continuously arranged between the adjacent first pixel openings R and the second pixel openings G; the light-emitting functional layer 107 includes a first color light-emitting functional layer EL1 and a second color light-emitting functional layer EL2, the first color light-emitting functional layer EL1 is arranged on the anode 104 at the first pixel opening R, and the second color light-emitting functional layer EL2 is arranged on the anode 104 at the second pixel opening G; the cathode 108 includes a first cathode C1 and a second cathode C2, the first cathode C1 is arranged on the first color light-emitting functional layer EL1 and contacts the side wall of the first partition structure D1, and the second cathode C2 is arranged on the second color light-emitting functional layer EL2 and contacts the side wall of the second partition structure D2.
[0078] In the display substrate provided in the embodiments of the present disclosure, a first partition structure D1 surrounding the first pixel opening R and a second partition structure D2 surrounding the second pixel opening G can be fabricated one by one on the organic pixel definition layer 105 using a wet step-by-step etching process. This fully utilizes the high selectivity of wet etching for different materials, completes the etching and patterning of the conductive isolation layer 106 to expose the anode 104, and does not cause etching damage to the anode 104. It also reduces foreign matter residue caused by poor dry etching processes. At the same time, the conductive isolation layer 106 can be used as an etching barrier layer for patterning the OLED device, preventing damage to the organic pixel definition layer 105 during the OLED device etching and patterning process. Therefore, the present disclosure eliminates the need for an inorganic pixel definition layer PDL2 to protect the organic pixel definition layer 105, thereby simplifying the process flow of the driver backplane, improving the pixel aperture ratio, and avoiding damage to the anode 104 caused by adding the inorganic pixel definition layer PDL2 patterning process (dry etching process), thereby ensuring the efficiency and life of the OLED device.
[0079] In some embodiments, in the above-mentioned display substrate provided in the embodiments of the present disclosure, as Figure 2 and Figure 3 As shown, a grid structure 109 can also be provided on the side of the conductive isolation layer 106 away from the base substrate 101. The material of the grid structure 109 can be an inorganic medium, a metal, a metal oxide, etc. Optionally, the grid structure 109 covers the conductive isolation layer 106 and does not overlap with the pixel opening K. The grid structure 109 and the conductive isolation layer 106 between adjacent pixel openings K form an undercut structure. The present disclosure can use the upper grid structure 109 as a mask and utilize the isotropic characteristics of wet etching to achieve inward etching of the conductive isolation layer 106, so that the grid structure 109 between adjacent pixel openings K forms an undercut structure with the conductive isolation layer 106, which can avoid the device film layer remaining in the undercut structure when the previously prepared OLED device is etched and patterned, resulting in the failure of the cathode 108 connection of the subsequent OLED device.
[0080] In some embodiments, in the above-mentioned display substrate provided in the embodiments of the present disclosure, as Figure 2 and Figure 3 As shown, the pixel opening K may further include a third pixel opening B; the conductive isolation layer 106 may further include a third partition structure D3 surrounding the third pixel opening B, the first partition structure D1 and the third partition structure D3 between the adjacent first pixel opening R and the third pixel opening B are integrally arranged (that is, the conductive isolation layer 106 is continuously arranged between the adjacent first pixel opening R and the third pixel opening B), and the second partition structure D2 and the third partition structure D3 between the adjacent second pixel opening G and the third pixel opening B are integrally arranged (that is, the conductive isolation layer 106 is continuously arranged between the adjacent second pixel opening G and the third pixel opening B), so that the conductive isolation layer 106 of the present disclosure presents a mesh structure as a whole; the light-emitting functional layer 107 may further include a third color light-emitting functional layer EL3, and the third color light-emitting functional layer EL3 is arranged on the anode 104 at the third pixel opening B; the cathode 108 also includes a third cathode C3, and the third cathode C3 is arranged on the third color light-emitting functional layer EL3 and contacts the side wall of the third partition structure D3. Optionally, the first color light-emitting functional layer EL1, the second color light-emitting functional layer EL2 and the third color light-emitting functional layer EL3 in the present disclosure can emit light of different colors, for example, the first color light-emitting functional layer EL1 emits red light, the second color light-emitting functional layer EL2 emits green light, and the third color light-emitting functional layer EL3 emits blue light, to achieve full-color display.
[0081] In some embodiments, in the above-mentioned display substrate provided in the embodiments of the present disclosure, as Figure 2 and Figure 3As shown, a first encapsulation layer 110 covering the first pixel opening R and the first partition structure D1, a second encapsulation layer 111 covering the second pixel opening G and the second partition structure D2, a third encapsulation layer 112 covering the third pixel opening B and the third partition structure D3, and a fourth encapsulation layer 113 covering the first encapsulation layer 110, the second encapsulation layer 111, and the third encapsulation layer 112 may also be provided. Optionally, the first encapsulation layer 110, the second encapsulation layer 111, and the third encapsulation layer 112 may be a single-layer inorganic encapsulation film or a stacked inorganic encapsulation film, and the fourth encapsulation layer 113 may include an organic encapsulation film TFE1 in contact with the first encapsulation layer 110, the second encapsulation layer 111, and the third encapsulation layer 112, and an inorganic encapsulation film TFE2 located on a side of the organic encapsulation film TFE1 away from the first encapsulation layer 110, the second encapsulation layer 111, and the third encapsulation layer 112.
[0082] Since OLED devices are extremely sensitive to water and oxygen, in order to ensure that the retained pixels are not damaged by water and oxygen intrusion during the photolithography process, the present disclosure uses a thin film encapsulation process to independently encapsulate each pixel after the OLED device is prepared. Specifically, the present disclosure uses a first encapsulation layer 110 to encapsulate the first color pixel, a second encapsulation layer 111 to encapsulate the second color pixel, and a third encapsulation layer 112 to encapsulate the third color pixel, thereby ensuring that each pixel becomes an independent sealed body, avoiding the problem of water and oxygen penetrating along the encapsulation layer or OLED film layer interface during the subsequent photolithography process (exposure and etching). The fourth encapsulation layer 113 can further prevent water and oxygen from intruding and damaging the OLED device, achieving ultimate protection for the OLED device.
[0083] In some embodiments, Figure 4 and Figure 5 Schematic diagram of the structure of the OLED device disclosed in the present invention is shown. Figure 4 As shown, the OLED device of the present disclosure can be a Singe RGB device, and accordingly the light-emitting functional layer 107 includes a hole injection layer HIL, a hole transport layer HTL, an optical adjustment layer R'G'B', a light-emitting material layer RGB, an electron transport layer ETL and an electron injection layer EIL. Figure 5 As shown, the OLED device of the present disclosure can also be a Tandem RGB device, and accordingly the light-emitting functional layer 107 includes a hole injection layer HIL, a first hole transport layer HTL1, a first optical adjustment layer R1'G1'B1', a first light-emitting material layer R1G1B1, a first electron transport layer ETL1, a charge generation layer CGL, a second hole transport layer HTL2, a second optical adjustment layer R2'G2'B2', a second light-emitting material layer R2G2B2, a second electron transport layer ETL2 and an electron injection layer EIL.
[0084] Based on the same inventive concept, an embodiment of the present disclosure provides a method for manufacturing the above-mentioned display substrate, which may include the following steps:
[0085] Providing a base substrate 101;
[0086] An anode 104 is formed on the base substrate 101;
[0087] A pixel definition layer 105 is formed on the layer where the anode 104 is located. The pixel definition layer 105 includes a pixel opening K. The orthographic projection of the pixel opening K on the base substrate 101 overlaps with the orthographic projection of the anode 104 on the base substrate 101. The pixel opening K includes a first pixel opening R and a second pixel opening G.
[0088] Depositing a conductive isolation layer 106 on the pixel definition layer 105;
[0089] The conductive isolation layer 106 at the first pixel opening R is removed by a wet etching process to form a first partition structure surrounding the first pixel opening R;
[0090] Depositing a first color light-emitting functional layer EL1 and a first cathode C1 on the conductive isolation layer 106;
[0091] Using the conductive isolation layer 106 as an etching barrier, dry-etch the first cathode C1 and the first color light-emitting functional layer EL1, leaving the first color light-emitting functional layer EL1 and the first cathode C1 on the first pixel opening R and the first partition structure;
[0092] The conductive isolation layer 106 at the second pixel opening G is removed by a wet etching process to form a second partition structure surrounding the second pixel opening G. The first partition structure and the second partition structure between the adjacent first pixel opening R and the second pixel opening G are integrally arranged;
[0093] Depositing a second color light-emitting functional layer EL2 and a second cathode C2 on the conductive isolation layer 106;
[0094] The second cathode C2 and the second color light-emitting functional layer EL2 are dry-etched to retain the second color light-emitting functional layer EL2 and the second cathode C2 on the second pixel opening G and the second partition structure.
[0095] In order to better understand the above-mentioned manufacturing method provided by the embodiment of the present disclosure, the following Figure 3 The manufacturing process of the display substrate is described in detail.
[0096] In the present disclosure, the display substrate that meets the requirements of the photolithography process can select LTPS, Oxide or LTPO process solutions. The present disclosure omits the manufacturing process of the lower thin film transistor array (i.e., the pixel driving circuit layer 102), and only describes in detail the film preparation process above the anode 104.
[0097] The first step, such as Figure 6 As shown, an anode 104 (ITO / Ag / ITO) and a pixel definition layer 105 of an organic material are prepared on the flat layer 103, and then a conductive isolation layer 106 and a cap layer 109' are sputter-deposited. The anode 104 can be a stacked structure composed of ITO / Ag / ITO, wherein the thickness of the ITO layer can be The thickness of the Ag layer can be The pixel definition layer 105 can be made of photosensitive acrylic resin material, and the first pixel opening R, the second pixel opening G and the third pixel opening B can be directly patterned by exposure, development and post-baking. The conductive isolation layer 106 can be prepared by low-temperature sputtering process, and the material can be selected from Cu, Al, Mo, AlNd, etc., and the thickness is designed to be The cap layer 109' can be made of an inorganic dielectric layer, such as SiNx, SiO2, SiON, SiC, etc., or the cap layer 109' can be made of a metal or metal oxide, such as Ti, ITO, IZO, etc. The thickness of the cap layer 109' can be
[0098] The second step is Figure 7 and Figure 8 As shown, the cap layer 109' is patterned into a grid structure 109 at one time through exposure and dry etching processes, and the underlying conductive isolation layer 106 is used as an etching barrier for the cap layer 109', thereby avoiding etching damage to the pixel definition layer 105 and the anode 104 below the conductive isolation layer 106. The photoresist PR can then be stripped off.
[0099] The third step, such as Figure 9 and Figure 10 As shown, a wet etching process is used to remove the conductive isolation layer 106 on the surface of the anode 104 at the first pixel opening R. Simultaneously, the isotropic nature of wet etching is utilized to form a ring-shaped undercut partition structure, i.e., a first partition structure D1, at the first pixel opening R. Because the etching solution has a large etching ratio for the ITO on the surface of the anode 104 to the conductive isolation layer 106, the ITO on the surface of the anode 104 remains completely intact.
[0100] The fourth step is as follows Figure 11 As shown, a first color light-emitting functional layer EL1 and a first cathode C1 are formed by vacuum evaporation, and then a first encapsulation layer 110 is formed by chemical vapor deposition (CVD). The first color light-emitting functional layer EL1 and the first cathode C1 are separated by a T-shaped undercut structure formed by the first partition structure D1 and the grid structure 109. Figure 24A schematic diagram of the patterned evaporation film formation caused by the partition structure (including the first partition structure D1, the second partition structure D2, and the third partition structure D3) is provided. The first pixel opening R is surrounded by the first partition structure D1 in an undercut form, while the second pixel opening G and the third pixel opening B are not surrounded by such an undercut structure. The first color light-emitting functional layer EL1 and the first cathode C1 of the first pixel opening R can be encapsulated by the first partition structure D1 and the first encapsulation layer 110 to form a pixel-level package. The first cathode C1 can be a mixed metal cathode or a composite thin film cathode structure, and the first encapsulation layer 110 can be a single-layer inorganic encapsulation film or a laminated inorganic encapsulation film.
[0101] In some embodiments, the first cathode C1 can be deposited by vacuum evaporation to form a metal layer (e.g., a double-layer structure consisting of a magnesium metal layer and an aluminum metal layer). A transparent oxide conductive layer (e.g., ITO, IZO, ITZO, AZO, etc.) can then be formed on the metal layer using a sputtering process. The composite thin-film cathode structure consisting of the metal layer and the transparent oxide conductive layer serves as the first cathode C1. The enhanced film coverage of the transparent oxide conductive layer can improve the electrical connection between the cathode 108 and the first partition structure D1. The specific fabrication methods for the subsequent second and third cathodes C2 and C3 can refer to the first cathode C1 and are not further described in this disclosure.
[0102] Step 5: Figure 12 and Figure 13 As shown, a photoresist PR is used to cover and protect the area where the first pixel opening R and the first partition structure D1 are located. Then, the first color light-emitting functional layer EL1, the first cathode C1, and the first encapsulation layer 110 deposited on the second pixel opening G, the third pixel opening B, and the conductive isolation layer 106 surrounding them are removed by dry etching. During the dry etching process, the conductive isolation layer 106 and the mesh structure 109 are used as etching stops. This completes the patterning process of the first color pixel (e.g., the red light device Roled).
[0103] Step 6: Figure 14 and Figure 15 As shown, the first encapsulation layer 110, the third pixel opening B and the conductive isolation layer 106 around the third pixel opening B are protected by photoresist PR through an exposure process, and then the conductive isolation layer 106 on the anode 104 at the second pixel opening G is etched away through a wet etching process to expose the anode 104 at the second pixel opening G. At the same time, the grid structure 109 is used as a mask to inwardly etch the conductive isolation layer 106 around the second pixel opening G to form a second partition structure D2 with an undercut shape.
[0104] Step 7: Figure 16As shown, the second color light-emitting functional layer EL2 and the second cathode C2 are prepared by a vacuum evaporation process, and then the second encapsulation layer 111 is prepared by a chemical vapor deposition (CVD) process; wherein the second color light-emitting functional layer EL2 and the second cathode C2 at the second pixel opening G are isolated by the approximately "T"-shaped undercut structure composed of the second partition structure D2 and the grid structure 109. The second color light-emitting functional layer EL2 and the second cathode C2 at the second pixel opening G can be wrapped by the second partition structure D2 and the second encapsulation layer 111 to form a pixel-level encapsulation. The second cathode C2 can be a mixed metal cathode or a composite thin film cathode structure, and the second encapsulation layer 111 can be a single-layer inorganic encapsulation film, or a stacked inorganic encapsulation film.
[0105] Step 8: Figure 17 and Figure 18 As shown, photoresist PR is used to cover and protect the area where the second pixel opening G and the second partition structure D2 are located. Then, the second color light-emitting functional layer EL2, the second cathode C2, and the second encapsulation layer 111 deposited on the first encapsulation layer 110, the third pixel opening B, and the conductive isolation layer 106 around the third pixel opening B are removed by dry etching. During the dry etching process, the first encapsulation layer 110, the conductive isolation layer 106, and the mesh structure 109 are used as etching barriers. This completes the patterning process of the second color pixel (e.g., the green light device Goled).
[0106] Step 9: Figure 19 and Figure 20 As shown, the first encapsulation layer 110 and the second encapsulation layer 111 are protected by a photoresist PR through an exposure process, and then the conductive isolation layer 106 on the anode 104 at the third pixel opening B is etched away through a wet etching process to expose the anode 104 at the second pixel opening G. At the same time, the grid structure 109 is used as a mask to inwardly etch the conductive isolation layer 106 around the third pixel opening B to form a third partition structure D3 with an undercut shape.
[0107] Step 10, such as Figure 21 As shown, a third color light-emitting functional layer EL3 and a third cathode C3 are formed by a vacuum evaporation process, and then a third encapsulation layer 112 is formed by a chemical vapor deposition (CVD) process. The third color light-emitting functional layer EL3 and the third cathode C3 at the third pixel opening B are isolated by the approximately "T"-shaped undercut structure formed by the third partition structure D3 and the grid structure 109. The third color light-emitting functional layer EL3 and the third cathode C3 at the third pixel opening B can be encapsulated by the third partition structure D3 and the third encapsulation layer 112 to form a pixel-level encapsulation. The third cathode C3 can be a mixed metal cathode or a composite thin film cathode structure, and the third encapsulation layer 112 can be a single-layer inorganic encapsulation film or a stacked inorganic encapsulation film.
[0108] Step 8: Figure 22 and Figure 23 As shown, a photoresist PR is used to cover and protect the third color light-emitting functional layer EL3, the third cathode C3, and the third encapsulation layer 112 on the third pixel opening B and the third partition structure D3. The third color light-emitting functional layer EL3, the third cathode C3, and the third encapsulation layer 112 deposited on the first encapsulation layer 110 and the second encapsulation layer 111 are then removed by dry etching. The first encapsulation layer 110 and the second encapsulation layer 111 serve as etching barriers during the dry etching process. This completes the patterning process of the third color pixel (e.g., a blue light device Boled).
[0109] Step 9: Figure 3 As shown, an organic encapsulation film TFE1 is formed by inkjet printing, and an inorganic encapsulation film TFE2 is formed by chemical vapor deposition (CVD). The organic encapsulation film TFE1 and the inorganic encapsulation film TFE2 are then used to form a fourth encapsulation layer 113 covering the first encapsulation layer 110, the second encapsulation layer 111, and the third encapsulation layer 112, thereby completing the fabrication of a full-color light-emitting device. In some embodiments, touch electrodes and color film elements (COE) can also be integrated.
[0110] Based on the same inventive concept, the present disclosure further provides a display device comprising the display substrate described above in the embodiments of the present disclosure. Because the principles underlying the display device's solution are similar to those of the display substrate described above, the implementation of the display device can refer to the embodiments of the display substrate described above, and any repetitions will not be repeated.
[0111] In some embodiments, the above-mentioned display device provided by the embodiments of the present disclosure may be any product or component with a display function, such as a mobile phone, a tablet computer, a television, a monitor, a laptop computer, a digital photo frame, a navigator, a smart watch, a fitness wristband, a personal digital assistant, etc. The display device includes but is not limited to components such as a radio frequency unit, a network module, an audio output & input unit, a sensor, a display unit, a user input unit, an interface unit, and a control chip. Optionally, the control chip is a central processing unit, a digital signal processor, a system-on-chip (SoC), etc. For example, the control chip may also include a memory, a power module, etc., and realize power supply and signal input and output functions through additionally provided wires, signal lines, etc. For example, the control chip may also include hardware circuits and computer executable codes, etc. The hardware circuit may include conventional very large scale integration (VLSI) circuits or gate arrays and existing semiconductors or other discrete components such as logic chips and transistors; the hardware circuit may also include field programmable gate arrays, programmable array logic, programmable logic devices, etc. In addition, those skilled in the art will understand that the above structure does not constitute a limitation on the above display device provided in the embodiment of the present disclosure. In other words, the above display device provided in the embodiment of the present disclosure may include more or fewer of the above components, or a combination of certain components, or different component arrangements.
[0112] Although the preferred embodiments of the present disclosure have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concepts. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present disclosure.
[0113] Obviously, those skilled in the art may make various changes and modifications to the embodiments of the present disclosure without departing from the spirit and scope of the embodiments of the present disclosure. Thus, if such changes and modifications of the embodiments of the present disclosure fall within the scope of the claims of the present disclosure and their equivalents, the present disclosure is intended to include such changes and modifications.
Claims
1. A display substrate, wherein: include: substrate; an anode, located on one side of the substrate; A pixel definition layer, which is a single layer of organic material. The pixel definition layer includes a pixel opening. The orthographic projection of the pixel opening on the base substrate overlaps with the orthographic projection of the anode on the base substrate. The pixel opening includes a first pixel opening and a second pixel opening. a conductive isolation layer, comprising a first partition structure surrounding the first pixel opening and a second partition structure surrounding the second pixel opening, wherein the first partition structure and the second partition structure are integrally arranged between adjacent first pixel openings and second pixel openings; a light-emitting functional layer, comprising a first color light-emitting functional layer and a second color light-emitting functional layer, wherein the first color light-emitting functional layer is disposed on the anode at the first pixel opening, and the second color light-emitting functional layer is disposed on the anode at the second pixel opening; The cathode includes a first cathode and a second cathode, wherein the first cathode is arranged on the first color luminescent functional layer and contacts the side wall of the first partition structure, and the second cathode is arranged on the second color luminescent functional layer and contacts the side wall of the second partition structure.
2. The display substrate according to claim 1, wherein: It also includes a grid structure located on the side of the conductive isolation layer away from the base substrate, the grid structure covers the conductive isolation layer and does not overlap with the pixel opening; the grid structure and the conductive isolation layer between adjacent pixel openings form an undercut structure.
3. The display substrate according to claim 1 or 2, wherein: The pixel opening further includes a third pixel opening; The conductive isolation layer further includes a third partition structure surrounding the third pixel opening, wherein the first partition structure and the third partition structure between the adjacent first pixel opening and the third pixel opening are integrally arranged, and the second partition structure and the third partition structure between the adjacent second pixel opening and the third pixel opening are integrally arranged; The light-emitting functional layer further includes a third color light-emitting functional layer, and the third color light-emitting functional layer is provided on the anode at the third pixel opening; The cathode further includes a third cathode, which is disposed on the third color light-emitting functional layer and contacts the sidewall of the third partition structure.
4. The display substrate according to claim 3, wherein: It also includes the first encapsulation layer covering the first pixel opening and the first partition structure, the second encapsulation layer covering the second pixel opening and the second partition structure, the third encapsulation layer covering the third pixel opening and the third partition structure, and the fourth encapsulation layer covering the first encapsulation layer, the second encapsulation layer and the third encapsulation layer.
5. The display substrate according to any one of claims 1 to 4, wherein: The light-emitting functional layer includes a hole injection layer, a hole transport layer, an optical adjustment layer, a light-emitting material layer, an electron transport layer and an electron injection layer.
6. The display substrate according to any one of claims 1 to 4, wherein: The light-emitting functional layer includes a hole injection layer, a first hole transport layer, a first optical adjustment layer, a first light-emitting material layer, a first electron transport layer, a charge generation layer, a second hole transport layer, a second optical adjustment layer, a second light-emitting material layer, a second electron transport layer and an electron injection layer.
7. A method for manufacturing a display substrate according to any one of claims 1 to 6, wherein: include: providing a substrate; forming an anode on the base substrate; forming a pixel definition layer on the layer where the anode is located, the pixel definition layer including a pixel opening, the orthographic projection of the pixel opening on the base substrate overlapping with the orthographic projection of the anode on the base substrate, and the pixel opening including a first pixel opening and a second pixel opening; depositing a conductive isolation layer on the pixel definition layer; Using a wet etching process to etch away the conductive isolation layer at the first pixel opening to form a first partition structure surrounding the first pixel opening; Depositing a first color light-emitting functional layer and a first cathode on the conductive isolation layer; Using the conductive isolation layer as an etching barrier, dry-etching the first cathode and the first color light-emitting functional layer to retain the first color light-emitting functional layer and the first cathode on the first pixel opening and the first partition structure; Using a wet etching process to etch away the conductive isolation layer at the second pixel opening to form a second partition structure surrounding the second pixel opening, wherein the first partition structure and the second partition structure between adjacent first pixel openings are integrally arranged; Depositing a second color light-emitting functional layer and a second cathode on the conductive isolation layer; The second cathode and the second color light-emitting functional layer are dry-etched to retain the second color light-emitting functional layer and the second cathode on the second pixel opening and the second partition structure.
8. The production method according to claim 7, wherein: After depositing a conductive isolation layer on the pixel definition layer and before forming a first partition structure surrounding the first pixel opening, the method further includes: A cap layer is deposited on the conductive isolation layer, and the conductive isolation layer is used as an etching barrier layer. The cap layer is dry-etched to form a grid structure, and the orthographic projection of the grid structure on the base substrate does not overlap with the orthographic projection of the pixel opening on the base substrate.
9. The production method according to claim 7 or 8, wherein: Forming a pixel definition layer on the layer where the anode is located, specifically comprising: A single organic material layer is deposited on the layer where the anode is located, and the organic material layer is sequentially exposed, developed and post-baked to form a pixel definition layer.
10. The production method according to any one of claims 7 to 9, wherein: After depositing a first color light-emitting functional layer and a first cathode on the conductive isolation layer, and before dry-etching the first cathode and the first color light-emitting functional layer using the conductive isolation layer as an etching barrier layer to retain the first color light-emitting functional layer and the first cathode on the first pixel opening and the first partition structure, the method further includes: A first encapsulation layer is deposited on the first cathode, and the first encapsulation layer is etched to retain the first pixel opening and the first partition structure.
11. The production method according to any one of claims 7 to 10, wherein: After depositing the second color light-emitting functional layer and the second cathode on the conductive isolation layer, and before dry-etching the second cathode and the second color light-emitting functional layer to retain the second color light-emitting functional layer and the second cathode on the second pixel opening and the second partition structure, the method further includes: A second encapsulation layer is deposited on the second cathode, and the second encapsulation layer is etched to retain the second pixel opening and the second partition structure.
12. The production method according to any one of claims 7 to 11, wherein: The pixel opening further includes a third pixel opening, and after dry etching the second cathode and the second color light-emitting functional layer to retain the second pixel opening and the second color light-emitting functional layer and the second cathode on the second partition structure, further includes: Using a wet etching process to etch away the conductive isolation layer at the third pixel opening to form a third partition structure surrounding the third pixel opening, wherein the first partition structure and the third partition structure are integrally arranged between adjacent first pixel openings and third pixel openings, and the second partition structure and the third partition structure are integrally arranged between adjacent second pixel openings and third pixel openings; depositing a third color light-emitting functional layer and a third cathode on the conductive isolation layer; The third cathode and the third color light-emitting functional layer are dry-etched to retain the third color light-emitting functional layer and the third cathode on the third pixel opening and the third partition structure.
13. The production method according to claim 12, wherein: After depositing a third color light-emitting functional layer and a third cathode on the conductive isolation layer, and before dry-etching the third cathode and the third color light-emitting functional layer to retain the third pixel opening and the third color light-emitting functional layer and the third cathode on the third partition structure, the method further includes: A third encapsulation layer is deposited on the third cathode, and the third encapsulation layer is etched to retain the third pixel opening and the third partition structure.
14. The production method according to claim 12 or 13, wherein: The second cathode and the second color light-emitting functional layer are dry-etched, including: using the conductive isolation layer as an etching barrier layer, and dry-etching and removing the second cathode and the second color light-emitting functional layer of the third pixel opening.
15. The production method according to any one of claims 12 to 14, wherein: Depositing any one of the first cathode, the second cathode, and the third cathode specifically includes: A metal layer is formed by vacuum evaporation process, and a transparent oxide conductive layer is formed on the metal layer by sputtering process. The metal layer and the transparent oxide conductive layer constitute any one of the first cathode, the second cathode and the third cathode.
16. A display device, wherein: The display substrate comprises the display substrate according to any one of claims 1 to 6.