Mask strip, preparation method thereof, mask substrate, and preparation method of mask plate

Abstract

This invention provides a mask strip and its preparation method, a mask substrate, and a mask plate. The mask strip includes a mask layer having a first side and a second side disposed opposite to each other. Multiple first openings are formed in the mask layer, and the second side is used for depositing an organic light-emitting material layer. It also includes a mesh pattern layer located on the first side of the mask layer, which at least covers a first distribution area of ​​the multiple first openings. The mesh pattern layer has multiple grooves or multiple second openings, and a second distribution area of ​​the grooves or second openings covers the first distribution area. The grooves or second openings are regularly shaped and uniformly distributed. This mask strip ensures mesh formation accuracy, avoiding problems such as excessively high resolution of the first openings in the mask layer leading to small openings affecting grasping accuracy, unequal spacing of the first openings in the mask layer causing inability to form a mesh, and irregular shapes of the first openings in the mask layer causing difficulties in mesh formation.

Description

Technical Field

[0001] This invention belongs to the field of display technology, and specifically relates to a mask strip and its preparation method, a mask substrate, and a mask plate preparation method. Background Technology

[0002] OLED (Organic Light-Emitting Diode) displays have attracted widespread attention due to their advantages such as self-illumination, low power consumption, thinness, flexibility, vibrant colors, high contrast, and fast response speed.

[0003] As a crucial step in the fabrication of OLED displays, improving the manufacturing precision and resolution of FMM (Fine Metal Mask) is of paramount importance. Summary of the Invention

[0004] This invention provides a mask strip and its preparation method, a mask substrate, and a mask plate. The mask strip ensures its screen-forming accuracy while avoiding problems such as: the first opening in the mask layer having too high resolution leading to an excessively small opening affecting grasping accuracy; the first opening in the mask layer having unequal spacing, making screen-forming impossible; or the first opening in the mask layer having irregular shapes, making screen-forming difficult.

[0005] This invention provides a mask strip, including a mask layer, the mask layer having a first side and a second side disposed opposite to each other, the mask layer having a plurality of first openings, and the second side being used for evaporating an organic light-emitting material layer;

[0006] It also includes a mesh pattern layer located on the first side of the mask layer, the mesh pattern layer at least covering the first distribution area of ​​the plurality of first openings;

[0007] The mesh pattern layer has multiple grooves or multiple second openings.

[0008] The second distribution area of ​​the plurality of grooves or the plurality of second openings covers the first distribution area;

[0009] The plurality of grooves or the plurality of second openings are regularly shaped and evenly distributed.

[0010] In some embodiments, the depth of the groove is greater than or equal to half the thickness of the mesh pattern layer, and less than the thickness of the mesh pattern layer.

[0011] In some embodiments, the opening size of the groove or the second opening ranges from 50 to 100 μm.

[0012] In some embodiments, the plurality of grooves or the plurality of second openings have the same size and shape when projected onto the mask layer.

[0013] The groove or the second opening has a centrally symmetrical orthographic projection shape on the mask layer.

[0014] In some embodiments, the material of the mesh pattern layer includes an organic resin material;

[0015] The material of the mask layer includes metal.

[0016] The present invention also provides a mask substrate, including a frame and at least one of the above-described mask strips.

[0017] At least two opposite ends of the mask strip are fixedly connected to the frame.

[0018] The present invention also provides a method for preparing a mask strip, comprising: preparing a mask layer; wherein the mask layer has a plurality of first openings;

[0019] A mesh pattern layer is coated on a first side of the mask layer to form a mesh pattern layer; the mesh pattern layer at least covers the first distribution area of ​​the plurality of first openings.

[0020] Multiple grooves or multiple second openings are formed in the mesh pattern layer through an exposure and development process;

[0021] The second distribution area of ​​the plurality of grooves or the plurality of second openings covers the first distribution area;

[0022] The plurality of grooves or the plurality of second openings are regularly shaped and evenly distributed.

[0023] In some embodiments, after a mesh pattern layer is formed on the first side of the mask layer, and before a pattern of multiple grooves or multiple second openings is formed in the mesh pattern layer, the method further includes:

[0024] The thickness of the mesh pattern layer is detected, and it is determined whether the thickness uniformity of the mesh pattern layer is less than or equal to 1%.

[0025] If not, apply the mesh pattern layer again until the thickness uniformity of the mesh pattern layer is less than or equal to 1%.

[0026] The present invention also provides a method for preparing a photomask, comprising:

[0027] Mask strips were prepared using the above-described preparation method;

[0028] The mask strip is stretched onto the frame to form a mask substrate;

[0029] The mesh pattern layer in the mask substrate is removed to form the mask plate.

[0030] In some embodiments, stretching the mask strip onto the frame to form a mask substrate includes:

[0031] The outline of the groove or second opening within the set area of ​​the mesh pattern layer is captured, the actual center coordinates of the set area are identified, and the difference between the actual center coordinates and the theoretical center coordinates is calculated by comparison.

[0032] The mask strip is moved according to the difference so that the actual center coordinates are consistent with the theoretical center coordinates, and then the mask strip is stretched onto the frame;

[0033] The step of removing the mesh pattern layer in the mask substrate to form the mask includes:

[0034] The screen pattern layer can be removed by wet etching with organic solvents, or by dry etching with exposure.

[0035] The beneficial effects of the present invention are as follows: The mask strip provided by the present invention, by setting a mesh pattern layer and opening multiple grooves or multiple second openings with regular shapes and uniform distribution in the mesh pattern layer, can achieve accurate meshing of the mask strip by identifying the contours of the grooves or second openings in the mesh pattern layer when the mask strip is meshed, thereby ensuring the meshing accuracy of the mask strip. At the same time, it avoids the problems of the first opening in the mask layer being too small due to excessively high resolution, affecting the grasping accuracy, or the first opening in the mask layer being unable to mesh due to unequal spacing, or the first opening in the mask layer being irregular in shape, making meshing difficult.

[0036] The mask substrate provided by the present invention, by employing the above-mentioned mask strip, can improve the screen-forming accuracy of the mask substrate and ensure that the accuracy of the mask layer in the mask substrate meets the usage requirements.

[0037] The method for preparing a mask provided by the present invention forms the mask by removing the mesh pattern layer in the above-mentioned mask substrate, which can improve the mesh pattern accuracy of the mask and ensure that the accuracy of the mask layer in the mask meets the requirements for use. Attached Figure Description

[0038] Figure 1a This is a schematic diagram of the aperture distribution in an FMM corresponding to a full HD OLED screen in related technologies;

[0039] Figure 1b This is a schematic diagram of the distribution of openings in an FMM corresponding to an ultra-high-definition OLED screen in related technologies;

[0040] Figure 1cThis is a schematic diagram showing the distribution of openings in an FMM corresponding to a VR / AR screen in related technologies;

[0041] Figure 2 This is a schematic diagram illustrating the capture of the opening pattern on the FMM (Foil Mesh Module) during the tensioning process in related technologies.

[0042] Figure 3a This is a top view schematic diagram of a mask strip provided in an embodiment of the present invention;

[0043] Figure 3b For along Figure 3a A structural cross-sectional view of the AA' section line;

[0044] Figure 3c For along Figure 3a Another structural cross-sectional view of the AA' section line;

[0045] Figure 4 This is a schematic diagram of the mesh tensioning of the mask strip in an embodiment of the present invention;

[0046] Figure 5a This is a top view schematic diagram of a mask strip and its mask layer in an embodiment of the present invention;

[0047] Figure 5b This is a top view schematic diagram of another mask strip and its mask layer in an embodiment of the present invention;

[0048] Figure 5c This is a top view schematic diagram of another mask strip and its mask layer in an embodiment of the present invention;

[0049] Figure 6 This is a schematic diagram of the mask strip preparation process in an embodiment of the present invention;

[0050] Figure 7 This is a top view of the mask substrate in an embodiment of the present invention;

[0051] Figure 8 This is a top view of the mask plate in an embodiment of the present invention;

[0052] Figure 9 This is a schematic diagram of the mask preparation process in an embodiment of the present invention. Detailed Implementation

[0053] To enable those skilled in the art to better understand the technical solution of the present invention, the following describes in further detail, with reference to the accompanying drawings and specific embodiments, a mask strip and its preparation method, a mask substrate, and a mask plate preparation method of the present invention.

[0054] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the described embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0055] Unless otherwise defined, the technical or scientific terms used in the embodiments of this disclosure should have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms "first," "second," and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0056] This document describes exemplary embodiments with reference to sectional views and / or plan views, which are idealized exemplary drawings. In the drawings, the thickness of layers and regions is enlarged for clarity. Therefore, variations in shape relative to the drawings are contemplated due to, for example, manufacturing techniques and / or tolerances. Therefore, exemplary embodiments should not be construed as limited to the shapes of the regions shown herein, but rather include shape deviations due to, for example, manufacturing processes. Thus, the regions shown in the drawings are schematic in nature, and their shapes are not intended to show the actual shapes of the regions of the device, nor are they intended to limit the scope of the exemplary embodiments.

[0057] This disclosure is not limited to the embodiments shown in the accompanying drawings, but includes modifications to the configuration based on the manufacturing process. Therefore, the areas illustrated in the drawings are schematic, and the shapes of the areas shown illustrate specific shapes of the areas, but are not intended to be limiting.

[0058] As AMOLED (Active-Matrix Organic Light-Emitting Diode) display panels expand in the AR (Augmented Reality) / VR (Virtual Reality) market, the demand for high-resolution products is increasing. As a crucial part of the OLED display panel manufacturing process, the fabrication precision of FMM (Fine Metal Mask) is particularly important.

[0059] like Figure 1a , Figure 1b and Figure 1c As shown in Table 1 below, with the gradual increase in display product resolution, the density of the openings 7 used for evaporation to form pixels in the FMM also increases (e.g., the opening density ≥ 1500ppi in a square area with a side length of one foot), and the size of the openings 7 gradually decreases (e.g., the diagonal size of the opening ≤ 11μm). However, the stretching accuracy of the FMM onto the mask frame is required to be higher (e.g., stretching accuracy ≤ 1.5μm). Therefore, stretching the FMM onto the mask frame requires higher process capabilities from the stretching equipment.

[0060] Table 1

[0061]

[0062] In related technologies, such as Figure 2 The diagram illustrates the method for capturing and measuring the opening pattern on an FMM during its stretching process. The stretching device uses a CCD (photocoupled device, such as a camera) to capture the outline of the opening 7 for pixel deposition within a localized area of ​​the FMM. It identifies the actual center coordinates O of the opening 7 outline within the localized area and compares them with the theoretical center coordinates P. The device calculates the positional differences (such as Dx, Dy, θ, etc.) that need to be compensated for by the actual center coordinates O of the opening 7 outline within the localized area of ​​the FMM. Then, the stretching device clamps the FMM with clamps 8 and moves it, thereby compensating for the positional differences of the actual center coordinates O of the opening 7 outline within the localized area of ​​the FMM. This makes the actual center coordinates O and the theoretical center coordinates P more consistent, ultimately ensuring that the positional accuracy of the FMM reaches the control benchmark.

[0063] Currently, high-precision screen printing equipment requires significant investment and has a long development cycle, which hinders the smooth implementation of high-resolution projects. In addition, to enhance the display effect of OLED display panels, various irregular pixel shapes or uneven pixel spacing are currently being designed. However, the pattern grasping solutions of screen printing equipment are limited. Such irregular pixel shapes and unevenly spaced pixels cannot effectively ensure the accuracy of mask production during the FMM screen printing process, which may lead to a loss of yield or even project failure.

[0064] To address the aforementioned problem of difficulty in controlling the accuracy of FMM (Film Mesh Maker) mesh, this invention provides a mask strip, such as... Figure 3a , Figure 3b and Figure 3c As shown, the mask strip includes a mask layer 1, which has a first side 101 and a second side 102 disposed opposite to each other. The mask layer 1 has a plurality of first openings 10, and the second side 102 is used for evaporating an organic light-emitting material layer. It also includes a mesh pattern layer 2 located on the first side 101 of the mask layer 1. The mesh pattern layer 2 covers at least the first distribution area S1 of the plurality of first openings 10. The mesh pattern layer 2 has a plurality of grooves 20 or a plurality of second openings 21, and the second distribution area S2 of the plurality of grooves 20 or the plurality of second openings 21 covers the first distribution area S1. The plurality of grooves 20 or the plurality of second openings 21 are regularly shaped and uniformly distributed.

[0065] The mask substrate is formed by stretching the mask strip onto the frame. The first opening 10 of the mask layer 1 in the mask strip is used for vapor deposition to form pixels in the OLED display panel, such as the organic light-emitting material layer for forming the pixels. The shape regularity of the groove 20 or the second opening 21 refers to a shape that can be defined and named, such as a rectangle, circle, triangle, parallelogram, or regular polygon. Irregular shape refers to a shape that cannot be defined or named.

[0066] like Figure 4 As shown, during the mask strip stretching process, the stretching device uses a CCD (photocoupled device, such as a camera) to capture the outlines of the regularly shaped and uniformly distributed grooves 20 or second openings 21 in the stretching pattern layer 2 of the mask strip. Then, it identifies the actual center coordinates O of the grooves 20 or second openings 21 in the stretching pattern layer 2 and compares the actual center coordinates O with the theoretical center coordinates P. It calculates the positional difference (such as Dx, Dy, θ, etc.) that needs to be compensated for in the actual center coordinates O of the grooves 20 or second openings 21 in the stretching pattern layer 2. Then, the stretching device clamps the mask strip and moves it to compensate for the positional difference of the actual center coordinates O of the grooves 20 or second openings 21 in the stretching pattern layer 2 of the mask strip, so that the actual center coordinates O and the theoretical center coordinates P tend to be consistent, and finally, the positional accuracy of the mask strip reaches the control benchmark.

[0067] In this embodiment, the mask strip is applicable in two main areas: firstly, in the fabrication of high-resolution display panels; for example... Figure 5aAs shown, the pixel density of the display panel is too high and the pixel size is very small. Correspondingly, the density of the first opening 10 in the mask layer 1 of the mask strip is too high and the size of the first opening 10 is very small. Furthermore, the mask strip requires high precision, necessitating high-precision screen-setting equipment to meet the requirements. Using the mask strip in this embodiment eliminates the need to invest in high-precision screen-setting equipment, thereby reducing operating costs. Secondly, it relates to the fabrication of display panels with unequal pixel spacing: such as... Figure 5b As shown, different areas of the display panel have pixel arrangements with different resolutions, corresponding to different areas on the mask layer 1 with first openings 10 of different resolutions. Because the spacing of the first openings 10 is not equal, it is impossible to confirm the deviation between the actual position and the theoretical position of each first opening 10 during mesh stretching. Using the mask strip in this embodiment, the mesh stretching accuracy of the mask strip can be ensured by grasping the grooves 20 or the second openings 21 in the mesh stretching pattern layer 2; the third is the fabrication of display panels with irregular pixel shapes, such as... Figure 5c As shown, in order to improve the aperture ratio of pixels in the display panel, various irregular pixel designs are used, corresponding to various irregular first openings 10 designs on the mask layer 1. Currently, the screen stretching device can only capture the outer contour of the regular-shaped first opening 10 to identify the center of the first opening 10. It is more difficult to identify the center of the irregular-shaped first opening 10. Using the mask strip in this embodiment, any irregular pixel design can be handled. The size and density of the groove 20 or the second opening 21 in the screen stretching pattern layer 2 can be designed according to the screen stretching requirements. When stretching, it is only necessary to ensure the screen stretching accuracy of the screen stretching pattern layer 2 in the mask strip.

[0068] The mask strip provided in this embodiment, by setting a mesh pattern layer 2 and opening multiple grooves 20 or multiple second openings 21 with regular shapes and uniform distribution in the mesh pattern layer 2, can achieve accurate meshing of the mask strip by recognizing the contours of the grooves 20 or second openings 21 in the mesh pattern layer 2 when the mask strip is meshed. This ensures the meshing accuracy of the mask strip and avoids the problems of the first opening 10 in the mask layer 1 being too small due to excessively high resolution, affecting the grasping accuracy, or the first opening 10 in the mask layer 1 being unable to mesh due to unequal spacing, or the first opening 10 in the mask layer 1 having irregular shape, making meshing difficult.

[0069] In some embodiments, the depth of the groove 20 is greater than or equal to half the thickness of the mesh pattern layer 2, and less than the thickness of the mesh pattern layer 2. This depth setting of the groove 20 allows the contour of the groove 20 to be accurately identified during mesh stretching.

[0070] In some embodiments, the opening size of the groove 20 or the second opening 21 ranges from 50 to 100 μm. This opening size range ensures that the contours of the groove 20 and the second opening 21 are accurately identified during mesh stretching, while also improving the grasping accuracy of the contours of the groove 20 and the second opening 21, thereby improving the mesh stretching accuracy of the mask strip.

[0071] The opening size of the groove 20 or the second opening 21 refers to the maximum radial dimension of the groove 20 or the second opening 21 with a regular shape. For example, the maximum radial dimension of a rectangle is the diagonal dimension of the rectangle; the maximum radial dimension of a circle is the diameter dimension of the circle; the maximum radial dimension of a triangle and a regular polygon is the diameter dimension of the circumcircle of the triangle and the regular polygon; and the maximum radial dimension of a parallelogram is the diagonal dimension of the parallelogram.

[0072] In some embodiments, the orthographic projections of the plurality of grooves 20 or the plurality of second openings 21 on the mask layer 1 are of the same size and shape, and the orthographic projection shapes of the grooves 20 or the second openings 21 on the mask layer 1 are centrally symmetrical. In some embodiments, the orthographic projection shapes of the grooves 20 or the second openings 21 on the mask layer 1 include centrally symmetrical shapes such as circles, rectangles, or regular polygons.

[0073] During the mask strip stretching process, the stretching device identifies the contours of all grooves 20 or all second openings 21, or identifies the contours of grooves 20 or second openings 21 within a local area on the mask strip, thereby ensuring that the stretching accuracy of the mask strip meets the control benchmark. The aforementioned configuration of the grooves 20 or second openings 21 further ensures that the contours of the grooves 20 and second openings 21 are accurately identified during stretching, improving the grasping accuracy of the contours of the grooves 20 and second openings 21, thereby improving the stretching accuracy of the mask strip.

[0074] In some embodiments, the material of the mesh pattern layer 2 includes organic resin materials, such as photoresist, organic compounds (i.e., OC), polyimide (PI), polycarbonate (PC), polymethyl methacrylate (PMMA), etc.; the material of the mask layer 1 includes metals, such as stainless steel, aluminum alloy, copper, aluminum, nickel, titanium alloy, tungsten steel, etc. The first opening 10 in the mask layer 1 enables the vapor deposition of the organic light-emitting material layer in the pixel. The material of the mesh pattern layer 2 is light-transmitting, and the light transmittance (e.g., light transmittance) at the groove 20 or the second opening 21 is different from the light transmittance of other areas of the mesh pattern layer 2. Therefore, the meshing device can identify the contour of the groove 20 or the second opening 21, and then control the meshing accuracy of the mask strip according to the contour of the groove 20 or the second opening 21, thereby achieving precise meshing of the mask strip.

[0075] Based on the above-described structure of the mask strip, embodiments of the present invention also provide a method for preparing the mask strip, such as... Figure 6As shown, it includes: step S101: preparing a mask layer 1; the mask layer 1 has a plurality of first openings 10;

[0076] In this step, the mask layer 1 is prepared on the substrate through a patterning process (including film deposition, exposure, development, etching, etc.), and then the mask layer 1 is separated from the substrate.

[0077] Step S102: A mesh pattern layer 2 is formed by coating the first side of the mask layer 1; the mesh pattern layer 2 covers at least the first distribution area of ​​the plurality of first openings 10;

[0078] In this step, an organic resin material, such as PR glue, is coated on the first side of the mask layer 1.

[0079] Step S103: A pattern of multiple grooves 20 or multiple second openings 21 is formed in the mesh pattern layer 2 by exposure and development process; the second distribution area of ​​the multiple grooves 20 or multiple second openings 21 covers the first distribution area; the multiple grooves 20 or multiple second openings 21 are regularly shaped and evenly distributed.

[0080] In this step, through exposure and development, grooves 20 or second openings 21 are etched on the mesh pattern layer 2 to form equally spaced, regularly shaped and uniformly sized patterns.

[0081] In some embodiments, after step S102 and before step S103, the method further includes: step S102': checking the thickness of the mesh pattern layer 2 and determining whether the thickness uniformity of the mesh pattern layer 2 is less than or equal to 1%; if not, coating the mesh pattern layer 2 again until the thickness uniformity of the mesh pattern layer 2 is less than or equal to 1%.

[0082] In this process, after the mesh pattern layer 2 is coated, the material of the mesh pattern layer 2 is prone to seepage at the first opening 10 of the mask layer 1, resulting in poor flatness and thickness uniformity (NG) of the mesh pattern layer 2. This leads to inaccurate or incorrect contour recognition of the groove 20 or the second opening 21 in the mesh pattern layer 2. Through step S102', the flatness and thickness uniformity of the mesh pattern layer 2 can be ensured to meet the usage standard (thickness uniformity ≤1%), thereby ensuring the accuracy of contour recognition of the groove 20 or the second opening 21 in the mesh pattern layer 2, and thus improving the mesh forming accuracy of the mask strip.

[0083] The mask strip provided in this embodiment, by setting a mesh pattern layer and opening multiple grooves or multiple second openings with regular shapes and uniform distribution in the mesh pattern layer, can achieve accurate meshing of the mask strip by recognizing the contours of the grooves or second openings in the mesh pattern layer when the mask strip is meshed. This ensures the meshing accuracy of the mask strip and avoids problems such as the first opening in the mask layer being too small due to excessively high resolution, affecting the grasping accuracy, the first opening in the mask layer being unable to mesh due to unequal spacing, or the first opening in the mask layer being irregular in shape, making meshing difficult.

[0084] This invention also provides a mask substrate, such as... Figure 7 As shown, it includes a frame 3 and at least one mask strip 4 as described in the above embodiments, with at least two opposite ends of the mask strip 4 fixedly connected to the frame 3.

[0085] By using the mask strip in the above embodiments, the meshing accuracy of the mask substrate can be improved, ensuring that the accuracy of the mask layer in the mask substrate meets the usage requirements.

[0086] This invention also provides a mask, such as... Figure 8 As shown, it includes a frame 3 and a mask layer 1. The mask layer 1 has an edge region 201 and a middle region 202. The edge region 201 surrounds the middle region 202. The edge region 201 of the mask layer 1 is fixedly connected to the frame 3. The mask layer 1 has a plurality of first openings 10, which are located in the middle region 202.

[0087] In some embodiments, the plurality of first openings 10 have regular shapes, such as rectangles, circles, regular polygons, etc. In some embodiments, the plurality of first openings 10 may also have irregular shapes. In some embodiments, the plurality of first openings 10 are evenly spaced. In some embodiments, the plurality of first openings 10 are not evenly spaced. In some embodiments, the plurality of first openings 10 are the same size and shape. In some embodiments, the plurality of first openings 10 are different sizes and shapes.

[0088] Based on the above-described structure of the photomask, this embodiment also provides a method for preparing the photomask, such as... Figure 9 As shown, it includes: preparing mask strip 4 by the preparation method in the above embodiments;

[0089] Four mask strips are stretched onto frame 3 to form mask substrate 5;

[0090] The mesh pattern layer in the mask substrate 5 is removed to form the mask plate 6.

[0091] In some embodiments, refer to Figure 4The process of stretching the mask strip 4 onto the frame 3 to form a mask substrate 5 includes: grasping the outline of the groove 20 or the second opening 21 within the set area of ​​the stretched pattern layer 2, identifying the actual center coordinate O of the set area, comparing and calculating the difference between the actual center coordinate O and the theoretical center coordinate P; moving the mask strip 4 according to the difference so that the actual center coordinate O is consistent with the theoretical center coordinate P, and then stretching the mask strip 4 onto the frame 3.

[0092] The designated area can be the entire area containing the groove 20 or the second opening 21 on the mesh pattern layer 2, or it can be a local area on the mesh pattern layer 2. The specific area of ​​the designated area is determined according to the required mesh precision.

[0093] In some embodiments, removing the mesh pattern layer 2 in the mask substrate 5 to form a mask 6 includes: removing the mesh pattern layer by wet etching with an organic solvent, or removing the mesh pattern layer by dry etching process.

[0094] The organic solvent can be N-methylformamide, which can be used to immerse the mask substrate 5 in the organic solvent to remove the mesh pattern layer.

[0095] The mask provided in this embodiment is formed by removing the mesh pattern layer in the mask substrate of the above embodiment, which can improve the mesh pattern accuracy of the mask and ensure that the accuracy of the mask layer in the mask meets the usage requirements.

[0096] It is understood that the above embodiments are merely exemplary implementations used to illustrate the principles of the present invention, and the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A mask strip, comprising a mask layer having a first side and a second side disposed opposite to each other, wherein a plurality of first openings are formed in the mask layer, and the second side is used for depositing an organic light-emitting material layer; characterized in that It also includes a mesh pattern layer located on the first side of the mask layer, the mesh pattern layer at least covering the first distribution area of ​​the plurality of first openings; The mesh pattern layer has multiple grooves or multiple second openings. The second distribution area of ​​the plurality of grooves or the plurality of second openings covers the first distribution area; The opening size of the groove or the second opening is larger than the opening size of the first opening; The plurality of grooves or the plurality of second openings are of the same size and shape, are regular in shape and are evenly distributed; The resolution of the first opening is higher than that of the second opening; or the spacing between the first openings is unequal; or the shape of the first opening is irregular.

2. The mask strip according to claim 1, characterized in that, The depth of the groove is greater than or equal to half the thickness of the mesh pattern layer, and less than the thickness of the mesh pattern layer.

3. The mask strip according to claim 1, characterized in that, The opening size of the groove or the second opening ranges from 50 to 100 µm.

4. The mask strip according to claim 1, characterized in that, The plurality of grooves or the plurality of second openings have the same size and shape when projected onto the mask layer. The groove or the second opening has a centrally symmetrical orthographic projection shape on the mask layer.

5. The mask strip according to claim 1, characterized in that, The material of the mesh pattern layer includes organic resin material; The material of the mask layer includes metal.

6. A mask substrate, comprising a frame, characterized in that, It also includes at least one mask strip as described in any one of claims 1-5, At least two opposite ends of the mask strip are fixedly connected to the frame.

7. A method for preparing a mask strip, characterized in that, include: A mask layer is prepared; the mask layer has multiple first openings; A mesh pattern layer is coated on the first side of the mask layer; The mesh pattern layer at least covers the first distribution area of ​​the plurality of first openings; Multiple grooves or multiple second openings are formed in the mesh pattern layer through an exposure and development process; The second distribution area of ​​the plurality of grooves or the plurality of second openings covers the first distribution area; The opening size of the groove or the second opening is larger than the opening size of the first opening; The plurality of grooves or the plurality of second openings are of the same size and shape, are regular in shape and are evenly distributed; The resolution of the first opening is higher than that of the second opening; or the spacing between the first openings is unequal; or the shape of the first opening is irregular.

8. The method for preparing the mask strip according to claim 7, characterized in that, After the mesh pattern layer is coated and formed on the first side of the mask layer, and before the pattern of multiple grooves or multiple second openings is formed in the mesh pattern layer, the method further includes: The thickness of the mesh pattern layer is detected, and it is determined whether the thickness uniformity of the mesh pattern layer is less than or equal to 1%. If not, apply the mesh pattern layer again until the thickness uniformity of the mesh pattern layer is less than or equal to 1%.

9. A method for preparing a photomask, characterized in that, include: The mask strip is prepared by the preparation method according to any one of claims 7-8; The mask strip is stretched onto the frame to form a mask substrate; The mesh pattern layer in the mask substrate is removed to form the mask plate.

10. The method for preparing a mask according to claim 9, characterized in that, The step of stretching the mask strip onto the frame to form a mask substrate includes: The outline of the groove or second opening within the set area of ​​the mesh pattern layer is captured, the actual center coordinates of the set area are identified, and the difference between the actual center coordinates and the theoretical center coordinates is calculated by comparison. The mask strip is moved according to the difference so that the actual center coordinates are consistent with the theoretical center coordinates, and then the mask strip is stretched onto the frame; The step of removing the mesh pattern layer in the mask substrate to form the mask includes: The screen pattern layer can be removed by wet etching with organic solvents, or by dry etching with exposure.

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