A method for simulating mask evaporation

Abstract

This invention relates to the field of display technology and provides a method for simulating mask evaporation, comprising: fixing a mask mesh; illuminating the mask with a light source; acquiring a spot image after passing through the mask using a camera system; and performing visual differentiation processing on the spot image to distinguish each spot into a pixel simulation area and a pixel shadow simulation area, thereby obtaining a simulated image of the evaporation process. The technical problem solved is that by using a light source to simulate the evaporation source and performing visual differentiation processing on the acquired spot image to distinguish each spot into a pixel simulation area and a pixel shadow simulation area, and by estimating whether the pixel shadow is within a reasonable range and whether the pixel position is offset based on the simulated pixel simulation area and pixel shadow simulation area, the design and fabrication of the pixel opening of the FMM can be verified in advance without actual on-machine evaporation, thus solving the problems of high cost and long cycle of existing on-machine evaporation tests for FMMs.

Description

Technical Field

[0001] This invention relates to the field of display technology, and in particular to a method for simulating mask evaporation. Background Technology

[0002] In the field of display technology, FMM (Fine Metal Mask) is a key material used in the manufacture of OLED (Organic Light Emitting Diode) panels. It is mainly used in the vacuum evaporation process to deposit RGB (red, green, and blue) sub-pixel materials onto the display panel through the pixel openings (AA areas) on the FMM, thereby achieving high-resolution display.

[0003] However, precision errors are unavoidable in actual FMM manufacturing. Large dimensional errors in the pixel opening areas of the FMM can severely impact the yield of subsequent display products. In the production of the actual display substrate, there are organic areas around the actual pixel areas whose thickness gradually decreases outwards until they disappear; these edge organic areas can be referred to as pixel shadows. Currently, the only method to determine if the FMM's precision error is within acceptable limits is on-site vapor deposition at the client's location. If the pixels on the vapor-deposited display substrate do not shift and the pixel shadows are within a controllable range, then the FMM is considered problem-free. However, if the aforementioned problems occur, severe issues may require readjusting the FMM parameters and restocking. This significantly impacts the downstream customer's vapor deposition schedule and production capacity. Furthermore, the cost of on-site vapor deposition testing of the FMM is high, not only due to the testing costs of the vapor deposition materials themselves (approximately hundreds of thousands of yuan per hour for vapor deposition) but also the time cost of a lengthy process debugging cycle.

[0004] Therefore, a method is needed to simulate the evaporation effect of a photomask, and to solve the problems of high cost and long cycle of existing FMM on-machine evaporation tests. Summary of the Invention

[0005] The purpose of this invention is to provide a method for simulating mask evaporation, which solves the technical problems of high cost and long cycle of on-machine evaporation test when verifying pixel shadows and pixel offsets generated by FMM in the prior art.

[0006] In a first aspect, embodiments of the present invention provide a method for simulating mask evaporation, comprising: fixing a mask with a mesh; irradiating the mask with a light source; acquiring a spot image after passing through the mask using a camera system; performing visualization differentiation processing on the spot image to distinguish each spot into a pixel simulation area and a pixel shadow simulation area, thereby obtaining a simulated image of the simulated evaporation.

[0007] Furthermore, the visualization differentiation process includes, based on the grayscale data of the spot image, designating spot areas with grayscale values ​​greater than a grayscale threshold as the pixel simulation area, and spot areas with grayscale values ​​less than the grayscale threshold as the pixel shadow simulation area.

[0008] Furthermore, the light spot area with a gray level equal to the gray level threshold is designated as the pixel simulation area or the pixel shadow simulation area.

[0009] Further, the step of obtaining the grayscale threshold includes: selecting a sample mask; acquiring a pixel image of a display substrate prepared by vapor deposition using the sample mask, the pixel image including a pixel area and a pixel shadow area; fixing the sample mask with a mesh; illuminating the sample mask with a light source; acquiring a sample spot image after passing through the sample mask using a camera system; aligning the edge of the sample spot image with the outer edge of the pixel shadow area; taking the grayscale value at the position corresponding to the edge of the sample spot image and the pixel area as the grayscale threshold, or taking the grayscale value at the position corresponding to the inner edge of the sample spot image and the pixel shadow area as the grayscale threshold.

[0010] Furthermore, the wavelength of the light source is adjusted so that the edge of the light spot image is aligned with the outer edge of the pixel shadow area.

[0011] Furthermore, the average of multiple gray values ​​at the corresponding positions of the sample spot image and the edge of the pixel region is taken as the gray value threshold, or the average of multiple gray values ​​at the corresponding positions of the sample spot image and the inner edge of the pixel shadow region is taken as the gray value threshold.

[0012] Furthermore, the sample spot image is divided into different grayscale threshold regions based on grayscale changes.

[0013] Furthermore, the wavelength range of the light source is 400~1000nm.

[0014] Furthermore, when the pixel aperture size of the mask is less than 20 micrometers, the wavelength of the light source is 700-1000 nanometers; when the pixel aperture size of the mask is greater than or equal to 20 micrometers and less than or equal to 50 micrometers, the wavelength of the light source is 600-700 nanometers; when the pixel aperture size of the mask is greater than 50 micrometers, the wavelength of the light source is 400-600 nanometers.

[0015] Furthermore, the camera system employs a CCD or CMOS sensor.

[0016] The embodiments of the present invention have at least the following technical effects:

[0017] The method for simulating mask evaporation provided in this invention requires first fixing the mask mesh, and then illuminating the mask with a light source. The light source can be analogous to the evaporation source of the evaporation equipment. Light propagation exhibits particle-like properties, as does the sublimation and diffusion of organic molecules driven by heat. Because the pixel opening size of the mask on the glass surface is larger than the actual pixel opening size, the organic matter, after passing through the pixel opening size, will deposit organic matter at the edge of individual sub-pixels due to the gradual expansion of the opening size, forming pixel shadows. In actual product manufacturing, the size of these pixel shadows needs to be controlled within a reasonable range; exceeding this range may cause color shifts in the screen, leading to product scrap. After light passes through the actual pixel opening size, it will also form a light spot diffraction due to the gradual expansion of the opening size. The light spot is brightest at the center and darkest towards the outside. Therefore, light diffraction can be used to simulate the pixel shadows formed by organic matter overflow during mask evaporation. The camera system captures images of the light spots after passing through the photomask. However, the human eye cannot discern subtle variations in brightness within these directly captured images. Therefore, visual differentiation processing is necessary to distinguish each light spot, identifying a pixel simulation area and a pixel shadow simulation area to obtain a simulated vapor deposition image. This simulated image clearly shows the pixel simulation and pixel shadow simulation areas for each light spot. The size of the pixel shadow simulation area is used to predict the actual pixel shadow size after vapor deposition. If the pixel shadow simulation area is too large, exceeding the product's acceptable range, the layout design dimensions can be modified based on the size of the pixel shadow simulation area. This ensures that the pixel opening size on the glass surface is more reasonable than the actual pixel opening size, guaranteeing that the pixel shadow actually vapor-deposited from the photomask is within a reasonable range.

[0018] In addition, after determining the pixel simulation area and pixel shadow simulation area of ​​the light spot, the distance between the light spots can also be obtained. The distance between the light spots is the spacing between the centers of the pixel simulation area, which is analogous to the distance between pixels after actual evaporation. The distance between the light spots can also be used to assess whether uncontrollable pixel position shifts occur.

[0019] This application uses a light source to simulate the evaporation source and performs visual differentiation processing on the collected light spot images. Each light spot is divided into a pixel simulation area and a pixel shadow simulation area. Based on the simulated pixel simulation area and pixel shadow simulation area, it is possible to predict whether the pixel shadow is within a reasonable range and whether the pixel position is offset. The design and fabrication of the pixel opening of the FMM can be verified in advance without actual on-machine evaporation, which shortens the verification cycle of the FMM and solves the problems of high cost and long cycle of existing FMM on-machine evaporation test. Attached Figure Description

[0020] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0021] Figure 1 A schematic flowchart of a method for simulating mask evaporation provided in an embodiment of the present invention;

[0022] Figure 2 This is a schematic diagram of the mask structure provided in an embodiment of the present invention;

[0023] Figure 3 The actual pixel FIB image provided in the embodiments of the present invention;

[0024] Figure 4 This is a schematic diagram simulating the light spot of a simulated photomask evaporation process, provided as an embodiment of the present invention.

[0025] Figure 5 This is a schematic flowchart illustrating the process of obtaining a grayscale threshold in a method for simulating mask evaporation, as provided in an embodiment of the present invention.

[0026] Icons: 1-mask; 10-pixel opening; 21-pixel area; 22-pixel shadow area; 31-pixel simulation area; 32-pixel shadow simulation area. Detailed Implementation

[0027] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless specifically defined as herein.

[0029] Those skilled in the art will understand that, unless specifically stated otherwise, the singular forms “a,” “an,” “the,” and “the” used herein may also include the plural forms. It should be further understood that the term “comprising” as used in this specification means the presence of the stated features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or combinations thereof. The term “and / or” as used herein includes all or any units and all combinations of one or more associated listed items.

[0030] For the first aspect, please refer to Figure 1 This invention provides a method for simulating mask evaporation, comprising: S101: fixing a mask with a mesh; S102: illuminating the mask with a light source; S103: acquiring a spot image after passing through the mask using a camera system; S104: performing visualization differentiation processing on the spot image, distinguishing each spot into a pixel simulation area and a pixel shadow simulation area, to obtain a simulated image of the evaporation process.

[0031] In this embodiment, the mask needs to be stretched and fixed first because it is also necessary to stretch and fix the mask before evaporation in actual evaporation. Then, a light source is used to illuminate the mask. The light source can be compared to the evaporation source of the evaporation equipment. The propagation of light has a particle-like property, and the sublimation and diffusion of organic molecules driven by thermal energy also has a particle-like property. Figures 2 to 4As shown, since the pixel opening 10 of the mask 1 has an opening size C1 on the glass surface S1 that is larger than the actual pixel opening size C2, the organic matter, after passing through the pixel opening size C2, will also deposit organic matter at the edge of the individual sub-pixel due to the gradual expansion of the opening size, forming a pixel shadow. In the actual product manufacturing process, the size of these pixel shadows needs to be controlled within a reasonable range. If it exceeds this range, it may cause color shift of the screen, resulting in product scrap. After light passes through the actual pixel opening size C2, it will also form light spot diffraction due to the gradual expansion of the opening size. The light spot is brightest at the center and gets darker towards the outside. Therefore, light diffraction can be used to simulate the pixel shadow formed by the overflow of organic matter during the evaporation of the mask. The light spot image after passing through the mask is captured by the camera system. For the light spot image directly captured by the camera system, the human eye cannot judge the subtle changes in brightness and darkness within the light spot. Therefore, it is necessary to perform visualization and differentiation processing on the obtained light spot, distinguishing each light spot into a pixel simulation area 31 and a pixel shadow simulation area 32, to obtain a simulated image of evaporation. The simulated image clearly shows the pixel simulation area and pixel shadow simulation area for each light spot. The size of the pixel shadow simulation area can be used to predict the actual pixel shadow size after evaporation. If the pixel shadow simulation area is too large, exceeding the product's acceptable range, the layout design dimensions can be modified based on the size of the pixel shadow simulation area. This allows for a more reasonable design of the pixel opening size C1 on the glass surface S1 compared to the actual pixel opening size C2. Using the simulated data, the resulting pixel shadow on the display substrate after evaporation can be predicted, ensuring that the pixel shadow actually evaporated from the mask is within a reasonable range.

[0032] In addition, after determining the pixel simulation area and pixel shadow simulation area of ​​the light spot, the distance between the light spots can also be obtained. The distance between the light spots is the spacing between the centers of the pixel simulation area, which is analogous to the distance between pixels after actual evaporation. The distance between the light spots can also be used to assess whether uncontrollable pixel position shifts occur.

[0033] This application uses a light source to simulate the evaporation source and performs visual differentiation processing on the collected light spot images. Each light spot is divided into a pixel simulation area and a pixel shadow simulation area. Based on the simulated pixel simulation area and pixel shadow simulation area, it is possible to predict whether the pixel shadow is within a reasonable range and whether the pixel position is offset. The design and fabrication of the pixel opening of the FMM can be verified in advance without actual on-machine evaporation, which solves the problems of high cost and long cycle of existing FMM on-machine evaporation test.

[0034] Optionally, the visualization differentiation process includes classifying areas with grayscale values ​​greater than a grayscale threshold as pixel simulation areas and areas with grayscale values ​​less than a grayscale threshold as pixel shadow simulation areas based on the grayscale data of the spot image. In this embodiment, the visualization differentiation process is based on the grayscale data of the spot image. The grayscale value of the spot changes from the center to the outside, with the outermost area having the lowest grayscale value. Using the grayscale threshold as the distinction boundary, areas with grayscale values ​​greater than the grayscale threshold are pixel simulation areas, and areas with grayscale values ​​less than the grayscale threshold are pixel shadow simulation areas. The pixel shadow simulation areas surround the pixel simulation areas. Preferably, grayscale data with grayscale values ​​greater than the grayscale threshold can be uniformly assigned the value X1, and grayscale data with grayscale values ​​less than the grayscale threshold can be uniformly assigned the value X2, with X1 being greater than X2, preferably much greater than X2. This way, the output simulation image can clearly distinguish between the pixel simulation areas and the pixel shadow simulation areas, facilitating subsequent evaluation.

[0035] Optionally, the spot area with a grayscale value equal to the grayscale threshold can be designated as either a pixel simulation area or a pixel shadow simulation area. In this embodiment, whether the spot area with a grayscale value equal to the grayscale threshold is a pixel simulation area or a pixel shadow simulation area is determined by the position when the grayscale threshold is set. During the process of obtaining the grayscale threshold, the spot image needs to be compared with the actual deposited pixel. If the grayscale threshold is the grayscale value of the actual pixel edge corresponding to the spot, then the spot area with a grayscale value equal to the grayscale threshold is designated as a pixel simulation area. If the grayscale threshold is the grayscale value of the inner edge of the pixel shadow corresponding to the spot, and the pixel shadow is a ring area, the area closest to the actual pixel edge is the inner edge of the pixel shadow, then the spot area with a grayscale value equal to the grayscale threshold is designated as a pixel shadow simulation area.

[0036] Optional, such as Figure 5 As shown, the steps for obtaining the grayscale threshold include:

[0037] S201: Select a sample mask and obtain a pixel image of the display substrate prepared by vapor deposition using the sample mask. The pixel image includes pixel areas and pixel shadow areas.

[0038] S202: Fix the sample mask plate with a tension mesh.

[0039] S203: Illuminate the sample mask using a light source.

[0040] S204: Use a camera system to acquire images of the sample spot after it passes through the sample mask.

[0041] S205: Align the edge of the sample spot image with the outer edge of the pixel shadow area.

[0042] S206: Take the gray value at the position corresponding to the edge of the sample spot image and the pixel area as the gray value threshold, or take the gray value at the position corresponding to the inner edge of the pixel shadow area in the sample spot image as the gray value threshold.

[0043] In this embodiment, a specific type of mask is selected as the sample mask. The sample mask may have actual vapor deposition results, or it may not have undergone vapor deposition, in which case vapor deposition is required. In short, it is necessary to obtain pixel images of the display substrate prepared using the sample mask through vapor deposition. Figure 3 The pixel image includes pixel region 21 ( Figure 3 (green area in the middle) and pixel shadow area 22 ( Figure 3 The black area surrounding the green area in the image), the produced display substrate is imaged using SEM (Scanning Electron Microscopy) or FIB-SEM to obtain high-resolution images of the pixels. Pixel boundaries and shadow areas (gradual transition areas caused by uneven evaporation) are clearly visible in the pixel images. The sample mask is fixed with a mesh; an image of the sample spot after the light source illuminates the sample mask is acquired. After aligning the edge of the sample spot image with the outer edge of the pixel shadow area in the pixel image, it can be seen that the central area of ​​the spot corresponds to the pixel area of ​​the pixel image, and the outer area of ​​the spot corresponds to the pixel shadow area of ​​the pixel image. The grayscale value of the spot also changes. Next, the grayscale value at the position corresponding to the edge of the pixel area in the sample spot image is taken as the grayscale threshold, or the grayscale value at the position corresponding to the inner edge of the pixel shadow area in the sample spot image is taken as the grayscale threshold.

[0044] If the gray value at the position corresponding to the edge of the sample spot image and the pixel area is taken as the gray value threshold, then the spot area with a gray value greater than or equal to the gray value threshold is taken as the pixel simulation area, and the spot area with a gray value less than the gray value threshold is taken as the pixel shadow simulation area; if the gray value at the position corresponding to the inner edge of the sample spot image and the pixel shadow area is taken as the gray value threshold, then the spot area with a gray value greater than the gray value threshold is taken as the pixel simulation area, and the spot area with a gray value less than or equal to the gray value threshold is taken as the pixel shadow simulation area.

[0045] Optionally, the wavelength of the light source can be adjusted so that the edge of the light spot in the light spot image is aligned with the outer edge of the pixel shadow area. In this embodiment, the size of the light spot is determined by the diffraction range of the light, which is mainly determined by the wavelength of the light (λ) and the aperture size (d), following the diffraction formula: θ≈λ / d, where θ is the diffraction angle. The smaller the aperture (smaller d) or the longer the wavelength (larger λ), the larger the diffraction range. The aperture size (d) is the aperture size of the mask, which is already determined. Therefore, if the edge of the light spot in the sample light spot image cannot be aligned with the outer edge of the pixel shadow in the pixel image, the size of the light spot can be adjusted by adjusting the wavelength of the light source.

[0046] Optionally, the average of multiple gray values ​​at the corresponding positions of the sample spot image and the pixel area edge can be used as the gray value threshold; or, the average of multiple gray values ​​at the corresponding positions of the sample spot image and the inner edge of the pixel shadow area can be used as the gray value threshold. In this embodiment, there are multiple gray values ​​at the corresponding positions of the sample spot image and the pixel area edge, and not all of them are necessarily the same. Similarly, the gray values ​​at the corresponding positions of the sample spot image and the pixel shadow area are not necessarily the same. Therefore, if the gray value at the corresponding position of the sample spot image and the pixel area edge is to be selected, the average of the gray values ​​at multiple points in this circle is used as the gray value threshold; if the gray value at the corresponding position of the sample spot image and the pixel shadow area inner edge is to be selected, the average of the gray values ​​at multiple points in this circle is used as the gray value threshold.

[0047] Optionally, the sample spot image can be divided into different grayscale threshold regions based on grayscale changes. In this embodiment, since the evaporation source used in a real evaporation machine may be a point evaporation source or a line evaporation source, the number of simulated light sources must match the number of evaporation sources. For example, if the evaporation source is a point evaporation source, then a point light source is selected; if the evaporation source is multiple point evaporation sources, then multiple point light sources are selected. However, since there are multiple adjustment devices for the evaporation beam inside the uniform cavity of the evaporation machine, the simulated spot may have different light intensity due to the different distances between the pixel opening and the light source, regardless of whether a point light source or a line light source is used. It is possible that the grayscale threshold corresponding to each spot is different. Therefore, it can be divided according to the size of the threshold. Taking the spot closest to the light source as the center, if the grayscale threshold of the surrounding spots does not differ from the grayscale threshold of the spot closest to the light source by more than 3%, it can be divided into the first grayscale threshold region; if the difference in grayscale threshold exceeds 3%, then a second grayscale threshold region is divided, and so on. There can even be a third grayscale threshold, a fourth grayscale threshold, etc. Therefore, it's understandable that the grayscale threshold isn't a single value, but rather multiple values. Different regions of the mask may have different grayscale thresholds.

[0048] Optionally, the layout of the subsequent simulated mask does not need to be the same as the sample mask; they can be different. After dividing the sample spot image into different grayscale threshold regions, different grayscale thresholds need to be selected for simulation based on the defined regions in the subsequent mask simulation. Here, taking the region defined in the subsequent mask as an example, the sample mask is defined as having a first grayscale threshold region where the difference between the grayscale threshold of the surrounding spots and the grayscale threshold of the spot closest to the light source does not exceed 3%. This determines the distance between the outermost pixel opening of the first grayscale threshold region of the sample mask and the light source. Therefore, in the subsequent mask simulation, the distance between the outermost pixel opening of the region using the first grayscale threshold and the light source should be less than or equal to the distance between the outermost pixel opening of the region using the first grayscale threshold region of the sample mask and the light source. This ensures that the subsequent prediction and evaluation results are more accurate.

[0049] Optionally, the wavelength range of the light source is 400~1000nm. In this embodiment, the pixel aperture size of the fine metal mask is typically in the range of 10-100 micrometers. Visible and near-infrared wavelengths (400-1000 nm) are sufficiently small compared to this size to produce a clear diffraction pattern, suitable for simulation. Moreover, visible and near-infrared wavelength light sources are relatively easy to obtain, reducing simulation costs. Preferably, the light source is an LED light source or a laser light source. Diffusion elements, such as frosted sheets, integrating spheres, and diffuse reflectors, can also be added to artificially increase the divergence angle, making it approach the uniform distribution of vapor-deposited particles. Especially when using a laser light source, diffusion elements must be added.

[0050] Optionally, when the pixel aperture size of the mask is less than 20 micrometers, the wavelength of the light source is 700-1000 nanometers; when the pixel aperture size of the mask is greater than or equal to 20 micrometers and less than or equal to 50 micrometers, the wavelength of the light source is 600-700 nanometers; and when the pixel aperture size of the mask is greater than 50 micrometers, the wavelength of the light source is 400-600 nanometers. In this embodiment, since the smaller the actual pixel aperture size of the mask, the ratio of the actual generated pixel shadow area to the real pixel area increases. Therefore, when using light diffraction to simulate the shadow of organic matter, the diffraction formula is: θ≈λ / d. If we want to simulate the situation where diffraction becomes stronger, we can only increase the wavelength of the light. By increasing the wavelength, the shadow area of ​​the simulated light spot can be made larger, which is equivalent to the phenomenon of increased shadow ratio during actual evaporation. The selection of the aforementioned light source wavelength is not only necessary during the simulated mask evaporation process, but also readily apparent in the process of obtaining the grayscale threshold. If the pixel aperture size of the selected sample mask is greater than 50 micrometers, then a light source with a wavelength of 400-600 nanometers should be used when irradiating the sample mask. This same wavelength should then be used when irradiating masks with pixel aperture sizes greater than 50 micrometers. Therefore, the grayscale threshold used may differ for masks with different pixel aperture sizes.

[0051] Preferably, when the pixel aperture size of the mask is greater than or equal to 20 micrometers and less than or equal to 50 micrometers, the wavelength of the light source is 633 nanometers; when the pixel aperture size of the mask is greater than 50 micrometers, the wavelength of the light source is 532 nanometers.

[0052] Optionally, the camera system employs a CCD or CMOS sensor. In this embodiment, the grayscale changes of the light spot require a high-resolution CCD or CMOS sensor to acquire. The advantage of using a CCD sensor is that its charge transfer efficiency (CTE) can reach 99.999%, making it suitable for low-light environments and capable of detecting extremely subtle grayscale changes (such as the brightness contrast between the center and edge of the light spot), which is suitable for subsequent more precise visualization and differentiation processing adapted to the human eye. However, when acquiring the light spot image of the entire mask, a CMOS sensor can also be considered, as it is faster and less expensive.

[0053] Those skilled in the art will understand that the steps, measures, and schemes in the various operations, methods, and processes discussed in this invention can be alternated, modified, combined, or deleted. Furthermore, other steps, measures, and schemes in the various operations, methods, and processes discussed in this invention can also be alternated, modified, rearranged, decomposed, combined, or deleted. Furthermore, steps, measures, and schemes in the prior art that are similar to those disclosed in this invention can also be alternated, modified, rearranged, decomposed, combined, or deleted.

[0054] In the description of this invention, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0055] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0056] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0057] In the description of this specification, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method of simulating a shadow mask evaporation, characterized by, The method comprises the following steps: fixing a mask in tension; irradiating the mask by using a light source; collecting a light spot image after the mask by using a camera system; performing visualized division processing on the light spot image, dividing each light spot into a pixel simulation area and a pixel shadow simulation area, and obtaining a simulation image of simulated evaporation; the visualized division processing comprises: according to the gray data of the light spot image, regarding a light spot area with a gray value greater than a gray threshold value as the pixel simulation area, and regarding a light spot area with a gray value less than the gray threshold value as the pixel shadow simulation area; the gray threshold value is determined according to an actual evaporation result of a sample mask.

2. The method of claim 1, wherein, regarding a light spot area with a gray value equal to the gray threshold value as the pixel simulation area or the pixel shadow simulation area.

3. The method of claim 1, wherein, The step of obtaining the gray threshold value comprises: selecting a sample mask, obtaining a pixel image of a display substrate prepared by using the sample mask for evaporation, the pixel image comprising a pixel area and a pixel shadow area; fixing the sample mask in tension; irradiating the sample mask by using a light source; collecting a sample light spot image after the sample mask by using a camera system; aligning a light spot edge of the sample light spot image with an outer edge of the pixel shadow area; taking a gray value at a position corresponding to an edge of the pixel area of the sample light spot image as the gray threshold value, or taking a gray value at a position corresponding to an inner edge of the pixel shadow area of the sample light spot image as the gray threshold value.

4. The method of claim 3, wherein, adjusting the wavelength of the light source so that the light spot edge of the light spot image is aligned with the outer edge of the pixel shadow area.

5. The method of claim 3, wherein, taking an average of multiple gray values at positions corresponding to the edge of the pixel area of the sample light spot image as the gray threshold value, or taking an average of multiple gray values at positions corresponding to the inner edge of the pixel shadow area of the sample light spot image as the gray threshold value.

6. The method of claim 3, wherein, dividing different gray threshold value areas according to gray changes of the sample light spot image.

7. The method of claim 1, wherein, The wavelength range of the light source is 400-1000 nm.

8. The method of claim 7, wherein, when the pixel opening size of the mask is less than 20 microns, the wavelength of the light source is 700-1000 nm; when the pixel opening size of the mask is greater than or equal to 20 microns and less than or equal to 50 microns, the wavelength of the light source is 600-700 nm; when the pixel opening size of the mask is greater than 50 microns, the wavelength of the light source is 400-600 nm.

9. The method of claim 1, wherein, The camera system uses a CCD or CMOS sensor.

Images