OLED display substrate and preparation method thereof

Abstract

The invention relates to the technical field of display, particularly provides an OLED display substrate and a preparation method thereof, and aims to solve the problem that a reflective anode film surface is eroded by an etching solution in a composition process of multiple exposure and etching. The display substrate includes: a substrate; a TFT driving layer; a reflective anode; the protective layer covers the reflecting anode, and the protective layer is made of an insulating material; a via hole is formed in the protection layer and exposes a local area of the reflection anode; the transparent oxide patterns are arranged on the protection layer and electrically connected with local areas of the corresponding reflection anodes through via holes, and the transparent oxide patterns are different in thickness for pixel units of different colors; an organic light emitting layer; the cathode is arranged on the organic light-emitting layer, and a micro-cavity structure is formed between the reflecting anode and the cathode of each pixel unit. And the film surface erosion of the reflective anode caused by the etching liquid in the composition process of multiple exposure and etching is avoided, so that the product yield and the display effect are effectively improved.

Description

Technical Field

[0001] The present application relates to the field of display technology, and particularly to an OLED display substrate and a method for manufacturing the same. Background Art

[0002] In the prior art, in order to improve the display effect of an organic light-emitting diode (OLED) device, reflective electrodes (such as a total reflection anode and a transparent or semi-transparent cathode) are usually disposed on both sides of the organic light-emitting layer to form an optical microcavity, and the microcavity resonance effect is utilized to improve the light-emitting efficiency and color purity of the device. When the light waves generated by the organic light-emitting layer are reflected multiple times within the microcavity structure, the light waves of certain specific wavelengths will be enhanced due to the resonance effect, thereby improving the intensity of light and the purity of color.

[0003] In practical applications, by precisely designing the microcavity structure and organic materials, emissions of different color wavelengths can be achieved to meet different display and lighting requirements. For example, by adjusting the thickness of indium tin oxide (ITO) of different sub-pixels, improvements in the light-emitting efficiency and chromaticity of different sub-pixels can be realized.

[0004] However, in the existing method for manufacturing an OLED display substrate, in order to manufacture the microcavity structure and form an anode ITO with different thicknesses, a patterning process of multiple exposures and etching is required. The etching solution will inevitably erode the surface of the underlying reflective anode film, which not only affects the reflection effect of the reflective anode, but also causes a change in the preset cavity length, thereby resulting in deterioration of the enhancement effect on the light of the preset wavelength and seriously affecting the light-emitting efficiency of the OLED display substrate.

[0005] Therefore, there is an urgent need in the art for a new manufacturing solution for an OLED display substrate to solve the above problems. Summary of the Invention

[0006] In order to overcome the above defects, the present application is proposed to solve or at least partially solve the technical problem that the etching solution erodes the surface of the reflective anode film in the patterning process of multiple exposures and etching.

[0007] In a first aspect, there is provided an OLED display substrate, including pixel units of multiple colors, including:

[0008] A substrate;

[0009] A TFT driving layer located on the substrate, including an active region, a gate, and source-drain electrodes;

[0010] A reflective anode located on the TFT driving layer and corresponding to the pixel units of the multiple colors one by one, the reflective anode being electrically connected to the corresponding source-drain electrodes;

[0011] A protective layer covering the reflective anode, wherein the protective layer is formed of an insulating material;

[0012] A via hole formed in the protective layer exposes a partial area of the reflective anode.

[0013] A transparent oxide pattern formed on the protective layer is electrically connected to a corresponding partial area of the reflective anode through the via hole, wherein the thickness of the transparent oxide pattern is different for pixel units of different colors.

[0014] An organic light-emitting layer corresponding to each pixel unit is formed on the transparent oxide pattern.

[0015] A cathode is formed on the organic light-emitting layer, and a microcavity structure is formed between the reflective anode and the cathode of each pixel unit.

[0016] In a technical solution of the above OLED display substrate, according to the color of the pixel unit, the transparent oxide pattern corresponding to the pixel unit may include 1 to 3 layers.

[0017] In a technical solution of the above OLED display substrate, the pixel units of multiple colors include red pixel units, green pixel units, and blue pixel units.

[0018] The transparent oxide pattern includes a first transparent oxide pattern, a second transparent oxide pattern, and a third transparent oxide pattern.

[0019] Wherein,

[0020] The first transparent oxide pattern is only formed on the protective layer at the red pixel unit and is electrically connected to a corresponding partial area of the reflective anode through the via hole.

[0021] The second transparent oxide pattern is only formed on the protective layer at the green pixel unit and on the first transparent oxide pattern. The second transparent oxide pattern formed on the protective layer at the green pixel unit is electrically connected to a corresponding partial area of the reflective anode through the via hole.

[0022] The third transparent oxide pattern is formed on the protective layer at the blue pixel unit and on the second transparent oxide pattern. The third transparent oxide pattern formed on the protective layer at the blue pixel unit is electrically connected to a corresponding partial area of the reflective anode through the via hole.

[0023] In a technical solution of the above OLED display substrate, the pixel units of multiple colors include red pixel units, green pixel units, and blue pixel units.

[0024] The transparent oxide pattern includes a first transparent oxide pattern, a second transparent oxide pattern, and a third transparent oxide pattern.

[0025] Among them,

[0026] The first transparent oxide pattern is disposed on the protective layer at the red pixel unit, in the vias at the green pixel unit, and in the vias at the blue pixel unit, and is electrically connected to local regions of the corresponding reflective anodes respectively;

[0027] The second transparent oxide pattern is only disposed on the protective layer at the green pixel unit and on the first transparent oxide pattern at the red pixel unit, wherein the second transparent oxide pattern disposed on the protective layer at the green pixel unit is electrically connected to the local region of the corresponding reflective anode through the first transparent oxide pattern in the corresponding via;

[0028] The third transparent oxide pattern is disposed on the protective layer at the blue pixel unit and on the second transparent oxide pattern, wherein the third transparent oxide pattern disposed on the protective layer at the blue pixel unit is electrically connected to the local region of the corresponding reflective anode through the first transparent oxide pattern in the corresponding via.

[0029] In a technical solution of the above OLED display substrate,

[0030] For the red pixel unit, the organic light-emitting layer is a red organic light-emitting layer;

[0031] For the green pixel unit, the organic light-emitting layer is a green organic light-emitting layer;

[0032] For the blue pixel unit, the organic light-emitting layer is a blue organic light-emitting layer.

[0033] In a technical solution of the above OLED display substrate,

[0034] For the red pixel unit, the green pixel unit, and the blue pixel unit, the organic light-emitting layer is a white organic light-emitting layer;

[0035] The display substrate further includes a red color film, a green color film, and a blue color film disposed on the cathode.

[0036] In a technical solution of the above OLED display substrate, the thickness of the protective layer is 1000 - 10000 angstroms.

[0037] In a technical solution of the above OLED display substrate, the material of the transparent oxide pattern is selected from the following group: ITO, IZO, AZO, and FTO.

[0038] In a second aspect, a method for manufacturing an OLED display substrate is provided. The OLED display substrate includes pixel units of multiple colors, and the method includes:

[0039] Form a TFT driving layer on a substrate, including an active region, a gate, and source-drain electrodes;

[0040] Form a reflective anode corresponding to the pixel units of the multiple colors on the TFT driving layer, and the reflective anode is electrically connected to the corresponding source-drain electrodes;

[0041] Form a protective layer to cover the reflective anode, wherein the protective layer is formed of an insulating material;

[0042] Form a via hole in the protective layer to expose a partial area of the reflective anode;

[0043] Form a transparent oxide pattern on the protective layer, which is electrically connected to the partial area of the corresponding reflective anode through the via hole, wherein the thickness of the transparent oxide pattern is different for pixel units of different colors;

[0044] Form an organic light-emitting layer corresponding to each pixel unit on the transparent oxide pattern;

[0045] Form a cathode on the organic light-emitting layer, wherein a microcavity structure is formed between the reflective anode and the cathode of each pixel unit.

[0046] In a technical solution of the above manufacturing method, forming the transparent oxide pattern on the protective layer includes: forming 1 to 3 layers of transparent oxide patterns corresponding to the pixel unit according to the color of the pixel unit.

[0047] In a technical solution of the above manufacturing method, the pixel units of the multiple colors include red pixel units, green pixel units, and blue pixel units;

[0048] Forming the transparent oxide pattern on the protective layer and being electrically connected to the partial area of the corresponding reflective anode through the via hole includes:

[0049] Through a first mask, form a first transparent oxide pattern only on the protective layer at the red pixel unit, and electrically connect it to the partial area of the corresponding reflective anode through the via hole;

[0050] Through a second mask, form a second transparent oxide pattern only on the protective layer at the green pixel unit and on the first transparent oxide pattern, wherein the second transparent oxide pattern formed on the protective layer at the green pixel unit is electrically connected to the partial area of the corresponding reflective anode through the via hole;

[0051] Through a third mask, a third transparent oxide pattern is formed on the protective layer at the blue pixel unit and on the second transparent oxide pattern, wherein the third transparent oxide pattern formed on the protective layer at the blue pixel unit is electrically connected to a local area of the corresponding reflective anode through the via hole.

[0052] In a technical solution of the above preparation method, the pixel units of multiple colors include red pixel units, green pixel units, and blue pixel units;

[0053] The forming of the transparent oxide pattern on the protective layer and electrically connecting it to a local area of the corresponding reflective anode through the via hole includes:

[0054] Through a first mask, a first transparent oxide pattern is formed on the protective layer at the red pixel unit, in the via holes at the green pixel unit, and in the via holes at the blue pixel unit, and is electrically connected to a local area of the corresponding reflective anode respectively;

[0055] Through a second mask, a second transparent oxide pattern is formed only on the protective layer at the green pixel unit and on the first transparent oxide pattern at the red pixel unit, wherein the second transparent oxide pattern formed on the protective layer at the green pixel unit is electrically connected to a local area of the corresponding reflective anode through the first transparent oxide pattern in the corresponding via hole;

[0056] Through a third mask, a third transparent oxide pattern is formed on the protective layer at the blue pixel unit and on the second transparent oxide pattern, wherein the third transparent oxide pattern formed on the protective layer at the blue pixel unit is electrically connected to a local area of the corresponding reflective anode through the first transparent oxide pattern in the corresponding via hole.

[0057] In a technical solution of the above preparation method, the forming of the organic light-emitting layer corresponding to each pixel unit on the transparent oxide pattern includes:

[0058] For the red pixel unit, a red organic light-emitting layer is formed;

[0059] For the green pixel unit, a green organic light-emitting layer is formed;

[0060] For the blue pixel unit, a blue organic light-emitting layer is formed,

[0061] wherein, the thickness of the transparent oxide pattern in the microcavity structure of the red pixel unit is the sum of the thicknesses of the first transparent oxide pattern, the second transparent oxide pattern, and the third transparent oxide pattern;

[0062] The thickness of the transparent oxide pattern in the microcavity structure of the green pixel unit is the sum of the thickness of the second transparent oxide pattern and the thickness of the third transparent oxide pattern;

[0063] The thickness of the transparent oxide pattern in the microcavity structure of the blue pixel unit is the thickness of the third transparent oxide pattern.

[0064] In a technical solution of the above preparation method, forming the organic light-emitting layer corresponding to each pixel unit on the transparent oxide pattern includes:

[0065] For the red pixel unit, the green pixel unit, and the blue pixel unit, a white organic light-emitting layer is formed;

[0066] The method further includes: forming a red color film sheet, a green color film sheet, and a blue color film sheet on the cathode,

[0067] Wherein, the thickness of the transparent oxide pattern in the microcavity structure of the red pixel unit is the sum of the thickness of the first transparent oxide pattern, the thickness of the second transparent oxide pattern, and the thickness of the third transparent oxide pattern;

[0068] The thickness of the transparent oxide pattern in the microcavity structure of the green pixel unit is the sum of the thickness of the second transparent oxide pattern and the thickness of the third transparent oxide pattern;

[0069] The thickness of the transparent oxide pattern in the microcavity structure of the blue pixel unit is the thickness of the third transparent oxide pattern.

[0070] In a technical solution of the above preparation method, when forming the protective layer, the thickness of the protective layer is 1000 - 10000 angstroms.

[0071] One or more of the above technical solutions of the present application have at least one or more of the following beneficial effects:

[0072] In implementing the technical solution of the OLED display substrate provided by the present application, by adopting a new protective layer process design to cover the reflective anode, the transparent oxide pattern is connected to the reflective anode through a via hole, avoiding the film surface erosion of the reflective anode caused by the etching solution in the lithography process of multiple exposures and etching, thereby effectively improving the product yield and display effect. Description of the Drawings

[0073] Referring to the accompanying drawings, the disclosure of the present application will become more understandable. It is easy for those skilled in the art to understand that: these drawings are only for illustrative purposes and are not intended to limit the protection scope of the present application. Among them:

[0074] Figure 1 is a main step flow chart of the preparation method of the OLED display substrate according to an embodiment of the present application;

[0075] Figures 2A - 2G is Figure 1 The cross-sectional schematic diagrams corresponding to the process steps of the preparation method shown;

[0076] Figures 3A - 3C The detailed cross-sectional schematic diagram corresponding to the process of step S5 in an embodiment of the present application;

[0077] Figures 4A - 4C The detailed cross-sectional schematic diagram corresponding to the process of step S5 in another embodiment of the present application;

[0078] Figure 5 is the cross-sectional schematic diagram of an OLED display substrate according to another embodiment of the present application. Specific Embodiments

[0079] Some embodiments of the present application will be described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principles of the present application and are not intended to limit the protection scope of the present application.

[0080] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the described embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0081] Unless otherwise defined, the technical terms or scientific terms used in the present application shall have the ordinary meanings understood by those of ordinary skill in the art in the field to which the present application belongs. The "first", "second", and similar terms used in the present application do not denote any order, quantity, or importance, but are only used to distinguish different components. The terms such as "including" or "comprising" mean that the elements or items appearing before this word cover the elements or items listed after this word and their equivalents, without excluding other elements or items. The terms such as "connected" or "coupled" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The terms such as "upper", "lower", "left", "right", etc. are only used to represent relative positional relationships, and when the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0082] The present application provides a method for preparing an OLED display substrate.

[0083] Please refer to both Figure 1 and Figures 2A - 2G , wherein, Figure 1It is a main step flowchart of a method for manufacturing an OLED display substrate according to an embodiment of the present application; Figures 2A - 2F is Figure 1 a cross-sectional schematic diagram corresponding to the process of each step of the shown manufacturing method.

[0084] The OLED display substrate includes pixel units A, B, C of multiple colors. As Figure 1 shown, the manufacturing method mainly includes the following steps S1 to S7.

[0085] Step S1, as Figure 2A shown, form a TFT (Thin Film Transistor) driving layer 110 on a substrate (Base) 100, including an active region 112, a gate 114, and source / drain electrodes 116, 117.

[0086] Specifically, the TFT driving layer 110 is used to drive the pixel units to control the display in the display area. In one example, as shown in the figure, the driving layer includes the following stacked structure: a lightshield 118 made of a metal material above the substrate 100, connected to one of the source / drain electrodes 116; a buffer layer (Buffer) 101, the buffer layer 101 covering the lightshield 118; the active region 112 above the buffer layer 101, the conductive active regions 115 on both sides of the active region 112, a gate insulating layer (GI) 113, and a gate (Gate) 114; an interlayer dielectric layer (ILD) 102, covering the gate, the active region 112, and the conductive active regions 115; source / drain electrodes 116, 117, respectively electrically connected to the conductive active regions 115 through vias in the interlayer dielectric layer 102.

[0087] Above the interlayer dielectric layer 102 is a passivation layer (PVX) 103, covering the source / drain electrodes 116, 117. Above the passivation layer 103 is a planarization layer (Resin) 104. Exemplarily, the passivation layer 103 is made of silicon nitride (SiN x ) material, and the planarization layer 104 is made of a resin material.

[0088] The TFT driving layer 110 includes multiple TFTs, respectively electrically connected to the pixel units. Figures 2A - 2F Only the TFT 111 electrically connected to the pixel unit A is shown in the figure.

[0089] Exemplarily, the TFT111 adopts a top-gate TFT, which has the characteristic of a short channel. Therefore, its on-state current Ion can be effectively increased, thus significantly improving the display effect of the panel and effectively reducing power consumption. In addition, since the overlapping area between the gate and the source-drain electrodes of the top-gate TFT is small, the parasitic capacitance generated is small, so the possibility of occurrence of defects such as GDS (Growing Dark Spot) is also reduced.

[0090] Step S2, as Figure 2B shown, form reflection anodes 121, 122, 123 corresponding one-to-one with the pixel units of the multiple colors on the TFT driving layer 110 (it should be noted that only the case where the reflection anode 121 is electrically connected to the corresponding source-drain electrode 116 is shown in the figure, and those skilled in the art can understand that the reflection anode 122 and the reflection anode 123 will also be electrically connected to the corresponding source-drain electrodes).

[0091] Among them, the pixel units of the multiple colors include a red pixel unit A, a green pixel unit B, and a blue pixel unit C. The reflection anodes 121, 122, 123 are flat and smooth metal films, prepared from materials such as aluminum, silver, titanium, or alloy materials, etc., and have excellent reflection effects to effectively enhance light output and adjust the optical interference effect.

[0092] Step S3, as Figure 2C shown, form a protective layer 105 to cover the reflection anodes 121, 122, 123, where the protective layer 105 is formed of an insulating material.

[0093] Exemplarily, the protective layer 105 can be prepared from an inorganic insulating material such as silicon nitride, silicon oxide, silicon oxynitride, etc.; or can be prepared from a transparent organic insulating material.

[0094] In one embodiment, when forming the protective layer 105, the thickness of the protective layer 105 is 1000 - 10000 angstroms.

[0095] The above protective layer 105 will adjust the cavity length of the microcavity structure together with the transparent oxide pattern 130 formed subsequently, so those skilled in the art can control the thickness of the protective layer 105 as needed.

[0096] In addition, in some technical solutions that adjust the cavity length of the microcavity structure through ITO layers with different thicknesses, the reflection anode is easily eroded during the process of preparing the ITO layer, thus affecting the reflection effect; in some other technical solutions that adjust the cavity length by controlling the thickness of the inorganic layer, it is usually necessary to etch and thin the inorganic layer, which makes the uniformity of the thickness of the inorganic layer poor, and further leads to inaccurate control of the cavity length of the microcavity structure.

[0097] Compared with the above technical solutions for adjusting the cavity length, the protective layer 105 in the embodiment of the present application covers the reflective anode, which can protect the reflective anode film surface from being corroded in subsequent processes and does not affect the reflective effect; at the same time, there is no need to adjust the cavity length by etching and thinning the inorganic layer, but a vapor deposition process is used to deposit a transparent oxide to control the cavity length, thereby ensuring good thickness uniformity and achieving the effect of taking into account both the reflective effect and the precise control of the cavity length.

[0098] Step S4, such as Figure 2D As shown, via holes 124 , 125 , and 126 are formed in the protection layer 105 to expose partial areas of the reflective anodes 121 , 122 , and 123 .

[0099] Step S5, such as Figure 2E As shown, a transparent oxide pattern 130 is formed on the protection layer 105 and electrically connected to the local areas of the corresponding reflective anodes 121 , 122 , and 123 through the via holes 124 , 125 , and 126 , wherein the transparent oxide pattern 130 has different thicknesses for pixel units of different colors.

[0100] Further, forming the transparent oxide pattern 130 on the protection layer 105 includes: forming 1 to 3 layers of the transparent oxide pattern 130 corresponding to the pixel unit according to the color of the pixel unit.

[0101] In one embodiment, step S5 specifically includes the following steps S511-S513:

[0102] Step S511, see Figure 3A Through the first mask, a first transparent oxide pattern 131 is formed only on the protection layer 105 at the red pixel unit A, and is electrically connected to a local area of ​​the corresponding reflective anode 121 through the via hole 124.

[0103] Step S512, see Figure 3B Through a second mask, a second transparent oxide pattern 132B, 132A is formed only on the protective layer 105 at the green pixel unit B and on the first transparent oxide pattern 131, wherein the second transparent oxide pattern 132B formed on the protective layer 105 at the green pixel unit B is electrically connected to a local area of ​​the corresponding reflective anode 122 through the via 125.

[0104] Step S513, see Figure 3C, through a third mask, third transparent oxide patterns 133C, 133B, 133A are formed on the protective layer 105 at the blue pixel unit C and on the second transparent oxide patterns 132B, 132A, wherein the third transparent oxide pattern 133C formed on the protective layer 105 at the blue pixel unit C is electrically connected to a partial area of the corresponding reflective anode 123 through the via 126.

[0105] In the above embodiment, the materials of the first transparent oxide pattern 131, the second transparent oxide patterns 132A, 132B, and the third transparent oxide patterns 133A, 133B, 133C are selected from the following group: ITO, IZO, AZO, and FTO. Among them, a delaminated interface can be observed between adjacent transparent oxide patterns by SEM (scanning electron microscope), such as a clear interface can be observed between the first transparent oxide pattern 131 and the second transparent oxide pattern 132A, and between the second transparent oxide pattern 132A and the third transparent oxide pattern 133A.

[0106] In the above steps, by forming the protective layer 105 to cover most of the areas of the reflective anodes 121, 122, 123, during the formation process of the transparent oxide pattern 130, the film surface range of the reflective anodes 121, 122, 123 in contact with the etching solution is greatly reduced, thereby effectively controlling film surface erosion.

[0107] In another embodiment, step S5 specifically includes the following steps S521 - S523:

[0108] Step S521, refer to Figure 4A , through a first mask, first transparent oxide patterns 231, 201, 202 are formed on the protective layer 105 at the red pixel unit A, in the via 125 at the green pixel unit B, and in the via 126 at the blue pixel unit C, and are electrically connected to partial areas of the corresponding reflective anodes 121, 122, 123 respectively.

[0109] Step S522, refer to Figure 4B , through a second mask, second transparent oxide patterns 232B, 232A are formed only on the protective layer 105 at the green pixel unit B and on the first transparent oxide pattern 231 of the red pixel unit A, wherein the second transparent oxide pattern 232B formed on the protective layer 105 at the green pixel unit B is electrically connected to a partial area of the corresponding reflective anode 122 through the first transparent oxide pattern 201 in the corresponding via.

[0110] Step S523, refer to Figure 4C, through a third mask, third transparent oxide patterns 233C, 233A, and 233B are formed on the protective layer 105 at the blue pixel unit C and on the second transparent oxide patterns 232A and 232B, wherein the third transparent oxide pattern 233C formed on the protective layer 105 at the blue pixel unit C is electrically connected to a partial area of the corresponding reflective anode 123 through the first transparent oxide pattern 202 in the corresponding via hole.

[0111] In the above steps, most of the areas of the reflective anodes 121, 122, and 123 are covered by the protective layer 105, and while forming the first transparent oxide pattern 231, the vias 125 and 126 are filled, further reducing the number of times the surface of the reflective anode film at the via holes contacts the etching solution, and further ensuring the smoothness of the reflective anodes 121, 122, and 123.

[0112] In the above embodiment, the materials of the first transparent oxide patterns 231, 201, and 202, the second transparent oxide patterns 232A and 232B, and the third transparent oxide patterns 233A, 233B, and 233C are selected from the following group: ITO, IZO, AZO, and FTO.

[0113] Step S6, as Figure 2F shown, an organic light-emitting layer 106 corresponding to each pixel unit A, B, and C is formed on the transparent oxide pattern 130. In the example shown in the figure, for the red pixel unit A, the green pixel unit B, and the blue pixel unit C, a white organic light-emitting layer 106 is formed.

[0114] Step S7, a cathode 107 is formed on the organic light-emitting layer 106, wherein a microcavity structure is formed between the reflective anodes 121, 122, and 123 and the cathode 107 of each pixel unit. Exemplarily, the cathode 107 is formed of an IZO material.

[0115] In the case of uniformly forming a white organic light-emitting layer, the method further includes: forming a red color film sheet, a green color film sheet, and a blue color film sheet on the cathode 107, so that the corresponding pixel units emit light of the corresponding colors.

[0116] As can be seen from, for example Figure 2G the thickness of the transparent oxide pattern 130 in the microcavity structure of the red pixel unit A is the sum of the thickness H1 of the first transparent oxide pattern, the thickness H2 of the second transparent oxide pattern, and the thickness H3 of the third transparent oxide pattern;

[0117] the thickness of the transparent oxide pattern 130 in the microcavity structure of the green pixel unit B is the sum of the thickness H2 of the second transparent oxide pattern and the thickness H3 of the third transparent oxide pattern;

[0118] The thickness of the transparent oxide pattern 130 in the microcavity structure of the blue pixel unit C is the thickness H3 of the third transparent oxide pattern.

[0119] Wherein, the thickness H1 of the first transparent oxide pattern, the thickness H2 of the second transparent oxide pattern, and the thickness H3 of the third transparent oxide pattern all refer to the corresponding thickness above the protective layer 105, excluding the thickness of filling the vias.

[0120] Exemplarily, in Figure 3C the thickness H1 of the first transparent oxide pattern refers to the thickness of the first transparent oxide pattern 131 above the protective layer 105, excluding the thickness of filling the via 124. In Figure 4C the thickness H1 of the first transparent oxide pattern refers to the thickness of the first transparent oxide pattern 231 above the protective layer 105, rather than the thickness of the first transparent oxide patterns 201 and 202 in the vias.

[0121] Different from the example of uniformly forming the white organic light-emitting layer, in an alternative embodiment, step S6 includes:

[0122] For the red pixel unit A, forming a red organic light-emitting layer;

[0123] For the green pixel unit B, forming a green organic light-emitting layer;

[0124] For the blue pixel unit C, forming a blue organic light-emitting layer,

[0125] Wherein, the thickness of the transparent oxide pattern 130 in the microcavity structure of the red pixel unit A is the sum of the thickness H1 of the first transparent oxide pattern, the thickness H2 of the second transparent oxide pattern, and the thickness H3 of the third transparent oxide pattern;

[0126] The thickness of the transparent oxide pattern 130 in the microcavity structure of the green pixel unit B is the sum of the thickness H2 of the second transparent oxide pattern and the thickness H3 of the third transparent oxide pattern;

[0127] The thickness of the transparent oxide pattern 130 in the microcavity structure of the blue pixel unit C is the thickness H3 of the third transparent oxide pattern.

[0128] In actual operation, the above thicknesses H1, H2, and H3 can be adjusted according to actual needs to form a good strong microcavity optical effect, so that when the light of each color interferes in the corresponding microcavity structure, the best interference conditions can be achieved, so that each color can obtain the best light intensity output at its resonance wavelength.

[0129] Based on the method described in the above steps S1 to S7, by adopting a brand-new protective layer process design to cover the reflective anode, the transparent oxide pattern is connected to the reflective anode through vias, avoiding the film surface erosion of the reflective anode caused by the etching solution in the lithography process of multiple exposures and etching, thereby effectively improving the product yield and display effect.

[0130] It should be noted that although the above steps are described in a specific order in the above embodiments, those skilled in the art can understand that in order to achieve the effects of the present application, different steps do not necessarily have to be executed in such an order. They can be executed simultaneously (in parallel) or in other orders, and the adjusted solutions are equivalent technical solutions to the technical solutions described in the present application, and thus will also fall within the protection scope of the present application.

[0131] On the other hand of the present application, an OLED display substrate is also provided, as Figure 2G shown, including pixel units A, B, and C of multiple colors, including:

[0132] Substrate 100;

[0133] The TFT driving layer 110 located on the substrate 100, including an active region 112, a gate 114, and source-drain electrodes 116 and 117;

[0134] Reflective anodes 121, 122, and 123 corresponding to the pixel units A, B, and C of multiple colors and located on the TFT driving layer 110, and the reflective anode 121 is electrically connected to the corresponding source-drain electrode 116;

[0135] The protective layer 105 covers the reflective anodes 121, 122, and 123, and the protective layer 105 is formed of an insulating material;

[0136] Vias 124, 125, and 126 are provided in the protective layer 105 to expose partial regions of the reflective anodes 121, 122, and 123;

[0137] A transparent oxide pattern 130 is provided on the protective layer 105 and is electrically connected to the partial regions of the corresponding reflective anodes 121, 122, and 123 through the vias 124, 125, and 126, and the thickness of the transparent oxide pattern 130 is different for different color pixel units;

[0138] An organic light-emitting layer 106 corresponding to each pixel unit is provided on the transparent oxide pattern 130;

[0139] A cathode 107 is disposed on the organic light-emitting layer 106, and a microcavity structure is formed between the reflective anodes 121, 122, 123 and the cathode 107 of each pixel unit.

[0140] In one embodiment, the thickness of the protective layer 105 is 1000 - 10000 angstroms.

[0141] Further, according to the color of the pixel unit, the corresponding transparent oxide pattern 130 of the pixel unit may include 1 to 3 layers.

[0142] The material of the transparent oxide pattern 130 is selected from the following group: ITO, IZO, AZO, and FTO.

[0143] Further, in one embodiment, the pixel units of multiple colors include a red pixel unit A, a green pixel unit B, and a blue pixel unit C;

[0144] The transparent oxide pattern 130 includes a first transparent oxide pattern 131, second transparent oxide patterns 132A, 132B, and third transparent oxide patterns 133A, 133B, 133C.

[0145] Among them, the first transparent oxide pattern 131 is only disposed on the protective layer 105 at the red pixel unit A and is electrically connected to a partial area of the corresponding reflective anode 121 through the via 124;

[0146] The second transparent oxide patterns 132A, 132B are only disposed on the protective layer 105 at the green pixel unit B and on the first transparent oxide pattern 131, and the second transparent oxide pattern 132B disposed on the protective layer 105 at the green pixel unit B is electrically connected to a partial area of the corresponding reflective anode 122 through the via 125;

[0147] The third transparent oxide patterns 133A, 133B, 133C are disposed on the protective layer 105 at the blue pixel unit C and on the second transparent oxide patterns 132A, 132B, and the third transparent oxide pattern 133C disposed on the protective layer 105 at the blue pixel unit C is electrically connected to a partial area of the corresponding reflective anode 123 through the via 126.

[0148] In another embodiment, please refer to Figure 5 A cross-sectional schematic diagram of an OLED display substrate according to another embodiment of the present application. The pixel units of multiple colors include a red pixel unit A, a green pixel unit B, and a blue pixel unit C;

[0149] The transparent oxide pattern 230 includes a first transparent oxide pattern 231, 201, 202, a second transparent oxide pattern 232A, 232B, and a third transparent oxide pattern 233A, 233B, 233C.

[0150] Among them, the first transparent oxide patterns 231, 201, 202 are disposed on the protective layer 105 at the red pixel unit A, in the vias 125 at the green pixel unit B, and in the vias 126 at the blue pixel unit C, and are electrically connected to local regions of the corresponding reflective anodes 121, 122, 123 respectively;

[0151] The second transparent oxide patterns 232B, 232A are only disposed on the protective layer 105 at the green pixel unit B and on the first transparent oxide pattern 231 of the red pixel unit A. Among them, the second transparent oxide pattern 232B disposed on the protective layer 105 at the green pixel unit B is electrically connected to a local region of the corresponding reflective anode 122 through the first transparent oxide pattern 201 in the corresponding via;

[0152] The third transparent oxide patterns 233C, 233A, 233B are disposed on the protective layer 105 at the blue pixel unit C and on the second transparent oxide patterns 232A, 232B. Among them, the third transparent oxide pattern 233C disposed on the protective layer 105 at the blue pixel unit C is electrically connected to a local region of the corresponding reflective anode 123 through the first transparent oxide pattern 202 in the corresponding via.

[0153] Further, as Figure 2G or Figure 5 shown, for the red pixel unit A, the green pixel unit B, and the blue pixel unit C, the organic light-emitting layer 106 is a white organic light-emitting layer;

[0154] The display substrate further includes a red color filter film, a green color filter film, and a blue color filter film (not shown) disposed on the cathode 107.

[0155] In another embodiment:

[0156] For the red pixel unit A, the organic light-emitting layer 106 is a red organic light-emitting layer;

[0157] For the green pixel unit B, the organic light-emitting layer 106 is a green organic light-emitting layer;

[0158] For the blue pixel unit C, the organic light-emitting layer 106 is a blue organic light-emitting layer.

[0159] In the above embodiments, the descriptions of the respective embodiments have their own emphases. For parts not described in detail or recorded in a certain embodiment, reference may be made to the relevant descriptions of other embodiments. All the above optional technical solutions can be combined arbitrarily to form the optional embodiments of the present application, which will not be elaborated one by one here.

[0160] So far, the technical solutions of the present application have been described in conjunction with one embodiment shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present application is obviously not limited to these specific embodiments. Without departing from the principle of the present application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present application.

Claims

1. An OLED display substrate, comprising pixel units (A, B, C) of multiple colors, characterized in that: include: Base (100); A TFT driving layer (110) located on the substrate (100), comprising an active area (112), a gate (114), and source and drain electrodes (116, 117); Reflective anodes (121, 122, 123) located on the TFT driving layer (110) and corresponding to the pixel units (A, B, C) of the multiple colors, the reflective anode (121) being electrically connected to the corresponding source-drain electrode (116); A protective layer (105) covering the reflective anodes (121, 122, 123), wherein the protective layer (105) is formed of an insulating material; Vias (124, 125, 126) are provided in the protective layer (105) to expose local areas of the reflective anodes (121, 122, 123); A transparent oxide pattern (130) disposed on the protective layer (105) is electrically connected to a local area of ​​a corresponding reflective anode (121, 122, 123) through the via holes (124, 125, 126), wherein the transparent oxide pattern (130) has different thicknesses for pixel units of different colors; An organic light-emitting layer (106) corresponding to each pixel unit is arranged on the transparent oxide pattern (130); A cathode (107) is arranged on the organic light-emitting layer (106), wherein a microcavity structure is formed between the reflective anode (121, 122, 123) and the cathode (107) of each pixel unit.

2. The display substrate according to claim 1, characterized in that: According to the color of the pixel unit, the transparent oxide pattern (130) corresponding to the pixel unit may include 1 to 3 layers.

3. The display substrate according to claim 2, characterized in that: The pixel units of the plurality of colors include a red pixel unit (A), a green pixel unit (B) and a blue pixel unit (C); The transparent oxide pattern (130) includes a first transparent oxide pattern (131), a second transparent oxide pattern (132A, 132B) and a third transparent oxide pattern (133A, 133B, 133C), in, The first transparent oxide pattern (131) is only arranged on the protective layer (105) at the red pixel unit (A), and is electrically connected to a local area of ​​the corresponding reflective anode (121) through the via hole (124); The second transparent oxide pattern (132A, 132B) is only arranged on the protective layer (105) at the green pixel unit (B) and on the first transparent oxide pattern (131), wherein the second transparent oxide pattern (132B) arranged on the protective layer (105) at the green pixel unit (B) is electrically connected to a local area of ​​the corresponding reflective anode (122) through the via hole (125); The third transparent oxide pattern (133A, 133B, 133C) is arranged on the protective layer (105) at the blue pixel unit (C) and on the second transparent oxide pattern (132A, 132B), wherein the third transparent oxide pattern (133C) arranged on the protective layer (105) at the blue pixel unit (C) is electrically connected to a local area of ​​the corresponding reflective anode (123) through the via hole (126).

4. The display substrate according to claim 2, characterized in that: The pixel units of the plurality of colors include a red pixel unit (A), a green pixel unit (B) and a blue pixel unit (C); The transparent oxide pattern (230) includes a first transparent oxide pattern (231, 201, 202), a second transparent oxide pattern (232A, 232B) and a third transparent oxide pattern (233A, 233B, 233C), in, The first transparent oxide pattern (231, 201, 202) is arranged on the protective layer (105) at the red pixel unit (A), in the via hole (125) at the green pixel unit (B), and in the via hole (126) at the blue pixel unit (C), and is electrically connected to the local area of ​​the corresponding reflective anode (121, 122, 123) respectively; The second transparent oxide pattern (232B, 232A) is only arranged on the protective layer (105) at the green pixel unit (B) and on the first transparent oxide pattern (231) of the red pixel unit (A), wherein the second transparent oxide pattern (232B) arranged on the protective layer (105) at the green pixel unit (B) is electrically connected to a local area of ​​the corresponding reflective anode (122) through the first transparent oxide pattern (201) in the corresponding via hole; The third transparent oxide pattern (233C, 233A, 233B) is arranged on the protective layer (105) at the blue pixel unit (C) and on the second transparent oxide pattern (232A, 232B), wherein the third transparent oxide pattern (233C) arranged on the protective layer (105) at the blue pixel unit (C) is electrically connected to a local area of ​​a corresponding reflective anode (123) through the first transparent oxide pattern (202) in the corresponding via hole.

5. The display substrate according to any one of claims 1 to 4, characterized in that: For the red pixel unit (A), the organic light-emitting layer (106) is a red organic light-emitting layer; For the green pixel unit (B), the organic light-emitting layer (106) is a green organic light-emitting layer; For the blue pixel unit (C), the organic light-emitting layer (106) is a blue organic light-emitting layer.

6. The display substrate according to any one of claims 1 to 4, characterized in that: For the red pixel unit (A), the green pixel unit (B) and the blue pixel unit (C), the organic light-emitting layer (106) is a white organic light-emitting layer; The display substrate further comprises a red color filter sheet, a green color filter sheet and a blue color filter sheet arranged on the cathode (107).

7. The display substrate according to claim 1, characterized in that: The thickness of the protective layer (105) is 1000-10000 angstroms.

8. The display substrate according to claim 1, characterized in that: The material of the transparent oxide pattern (130) is selected from the following group: ITO, IZO, AZO and FTO.

9. A method for preparing an OLED display substrate, wherein the OLED display substrate comprises pixel units of multiple colors, characterized in that: include: A TFT driving layer (110) is formed on a substrate (100), comprising an active region (112), a gate (114), and source and drain electrodes (116, 117); Forming reflective anodes (121, 122, 123) corresponding one-to-one to the pixel units (A, B, C) of the multiple colors on the TFT driving layer (110), wherein the reflective anode (121) is electrically connected to the corresponding source-drain electrode (116); forming a protective layer (105) to cover the reflective anodes (121, 122, 123), wherein the protective layer (105) is formed of an insulating material; Forming via holes (124, 125, 126) in the protective layer (105) to expose local areas of the reflective anodes (121, 122, 123); forming a transparent oxide pattern (130) on the protective layer (105), and electrically connecting the transparent oxide pattern (130) to a local area of ​​a corresponding reflective anode (121, 122, 123) through the via holes (124, 125, 126), wherein the transparent oxide pattern (130) has different thicknesses for pixel units of different colors; forming an organic light-emitting layer (106) corresponding to each pixel unit on the transparent oxide pattern (130); A cathode (107) is formed on the organic light-emitting layer (106), wherein a microcavity structure is formed between the reflective anode (121, 122, 123) and the cathode (107) of each pixel unit.

10. The preparation method according to claim 9, characterized in that: The forming of the transparent oxide pattern (130) on the protective layer (105) comprises: forming 1 to 3 layers of transparent oxide patterns (130) corresponding to the pixel units according to the colors of the pixel units.

11. The preparation method according to claim 10, characterized in that: The pixel units of the plurality of colors include a red pixel unit (A), a green pixel unit (B) and a blue pixel unit (C); The transparent oxide pattern (130) is formed on the protective layer (105), and is electrically connected to a local area of ​​a corresponding reflective anode (121, 122, 123) through the via holes (124, 125, 126), comprising: Forming a first transparent oxide pattern (131) only on the protective layer (105) at the red pixel unit (A) through a first mask, and electrically connecting the first transparent oxide pattern (131) to a local area of ​​a corresponding reflective anode (121) through the via hole (124); Forming a second transparent oxide pattern (132A, 132B) only on the protective layer (105) at the green pixel unit (B) and on the first transparent oxide pattern (131) through a second mask, wherein the second transparent oxide pattern (132B) formed on the protective layer (105) at the green pixel unit (B) is electrically connected to a local area of ​​the corresponding reflective anode (122) through the via hole (125); A third transparent oxide pattern (133A, 133B, 133C) is formed on the protective layer (105) at the blue pixel unit (C) and on the second transparent oxide pattern (132A, 132B) through a third mask, wherein the third transparent oxide pattern (133C) formed on the protective layer (105) at the blue pixel unit (C) is electrically connected to a local area of ​​a corresponding reflective anode (123) through the via hole (126).

12. The preparation method according to claim 10, characterized in that: The pixel units of the plurality of colors include a red pixel unit (A), a green pixel unit (B) and a blue pixel unit (C); The transparent oxide pattern (130) is formed on the protective layer (105), and is electrically connected to a local area of ​​a corresponding reflective anode (121, 122, 123) through the via holes (124, 125, 126), comprising: Through a first mask, a first transparent oxide pattern (231, 201, 202) is formed on the protective layer (105) at the red pixel unit (A), in the via hole (125) at the green pixel unit (B), and in the via hole (126) at the blue pixel unit (C), and is electrically connected to local areas of corresponding reflective anodes (121, 122, 123), respectively; Forming a second transparent oxide pattern (232B, 232A) only on the protective layer (105) at the green pixel unit (B) and on the first transparent oxide pattern (231) of the red pixel unit (A) through a second mask, wherein the second transparent oxide pattern (232B) formed on the protective layer (105) at the green pixel unit (B) is electrically connected to a local area of ​​a corresponding reflective anode (122) through the first transparent oxide pattern (201) in the corresponding via hole; A third transparent oxide pattern (233C, 233A, 233B) is formed on the protective layer (105) at the blue pixel unit (C) and on the second transparent oxide pattern (232A, 232B) through a third mask, wherein the third transparent oxide pattern (233C) formed on the protective layer (105) at the blue pixel unit (C) is electrically connected to a local area of ​​a corresponding reflective anode (123) through the first transparent oxide pattern (233C) in the corresponding via hole.

13. The preparation method according to any one of claims 9 to 12, characterized in that: The step of forming an organic light-emitting layer corresponding to each pixel unit on the transparent oxide pattern (130) comprises: For the red pixel unit (A), a red organic light emitting layer is formed; For the green pixel unit (B), a green organic light emitting layer is formed; For the blue pixel unit (C), a blue organic light emitting layer is formed. The thickness of the transparent oxide pattern (130) in the microcavity structure of the red pixel unit (A) is the sum of the thickness of the first transparent oxide pattern, the thickness of the second transparent oxide pattern and the thickness of the third transparent oxide pattern; The thickness of the transparent oxide pattern (130) in the microcavity structure of the green pixel unit (B) is the sum of the thickness of the second transparent oxide pattern and the thickness of the third transparent oxide pattern; The thickness of the transparent oxide pattern (130) in the microcavity structure of the blue pixel unit (C) is a third transparent oxide pattern thickness.

14. The preparation method according to any one of claims 9 to 12, characterized in that: The method of forming an organic light-emitting layer (106) corresponding to each pixel unit on the transparent oxide pattern (130) comprises: For the red pixel unit (A), the green pixel unit (B) and the blue pixel unit (C), a white organic light-emitting layer (106) is formed; The method further comprises: forming a red color filter sheet, a green color filter sheet and a blue color filter sheet on the cathode (107), The thickness of the transparent oxide pattern (130) in the microcavity structure of the red pixel unit (A) is the sum of the thickness of the first transparent oxide pattern, the thickness of the second transparent oxide pattern and the thickness of the third transparent oxide pattern; The thickness of the transparent oxide pattern (130) in the microcavity structure of the green pixel unit (B) is the sum of the thickness of the second transparent oxide pattern and the thickness of the third transparent oxide pattern; The thickness of the transparent oxide pattern (130) in the microcavity structure of the blue pixel unit (C) is a third transparent oxide pattern thickness.

15. The preparation method according to claim 9, characterized in that: When the protective layer (105) is formed, the thickness of the protective layer (105) is 1000-10000 angstroms.

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