Vapor deposition mask plate assembly and manufacturing method of display substrate

Abstract

The invention provides an evaporation mask plate assembly and a manufacturing method of a display substrate, the evaporation mask plate assembly is used for forming a pixel pattern on a mother board through evaporation, the mother board is provided with a long edge and a short edge, the mother board comprises an evaporation effective area, the evaporation effective area is internally provided with at least one single-screen area with the extending length in the extending direction of the long side, the evaporation effective area is divided into N sub evaporation areas in the extending direction of the long side, and N is a positive integer larger than or equal to 2; the evaporation mask plate assembly comprises N sub-mask plates, the sub-mask plates stretch in the extending direction of the short edges, the pixel pattern of one sub-mask plate corresponds to the pixel pattern of one sub-evaporation area, and the pixel patterns of the N sub-mask plates are spliced and combined to form the pixel pattern of the whole evaporation effective area. According to the vapor deposition mask plate assembly and the manufacturing method of the display substrate, the problem that the number of pieces arranged on a mother board is limited can be solved.

Description

Technical Field

[0001] The present invention relates to the field of display technology, and in particular, to an evaporation mask template assembly and a method for manufacturing a display substrate. Background Art

[0002] AMOLED (Active Matrix Organic Light Emitting Diode) is a display technology widely used in devices such as smart phones, TVs, smart watches, and in-vehicle displays. AMOLED display screens can achieve higher contrast and a wider color range. With the popularization of AMOLED display screens in small and medium-sized display products, AMOLED display screens are gradually expanding towards medium and large sizes, large sizes, and even extra-large sizes.

[0003] The evaporation technology is a key step in the manufacturing process of AMOLED display screens for forming a thin film of organic light-emitting materials. However, in the evaporation process of related technologies, there are problems such as limited number of wafer arrangements on the mother board when manufacturing large-sized screens. Summary of the Invention

[0004] To solve at least one of the above-mentioned technical problems in the related art, embodiments of the present disclosure provide an evaporation mask template assembly and a method for manufacturing a display substrate.

[0005] The technical solutions provided by the embodiments of the present disclosure are as follows:

[0006] In a first aspect, embodiments of the present disclosure provide an evaporation mask template assembly for evaporating and forming a pixel pattern on a mother board. The mother board has a long side and a short side, and the mother board includes an evaporation effective area. At least one single-screen area with an extension length along the extension direction of the long side is provided in the evaporation effective area, and the evaporation effective area is divided into N sub-evaporation areas along the extension direction of the long side, where N is a positive integer greater than or equal to 2; the evaporation mask template assembly includes: N sub-mask templates, the sub-mask templates are meshed along the extension direction of the short side, and the pixel pattern of one sub-mask template corresponds to the pixel pattern of one sub-evaporation area. The pixel patterns of the N sub-mask templates are spliced and combined to form the pixel pattern of the entire evaporation effective area.

[0007] Exemplarily, the evaporation mask template assembly includes M mask units, where M is a positive integer greater than or equal to 2; the M mask units are configured such that the M mask units form corresponding pixel patterns on the mother board through M evaporation processes in sequence, and one mask unit corresponds to a single evaporation process;

[0008] Wherein, each of the mask plate units includes: at least one of the sub-mask plates and at least one baffle plate, wherein, in the same mask plate unit, the sub-mask plate and the baffle plate are configured to be alternately arranged in sequence along the long side extension direction; the sub-evaporation regions corresponding to the sub-mask plates in different mask plate units are configured to be alternately arranged along the long side extension direction.

[0009] Exemplarily, in the same mask plate unit, at least one of the baffle plates and at least one of the sub-mask plates adjacent thereto are connected as an integral structure; or, at least one of the baffle plates and at least one of the sub-mask plates adjacent thereto are stacked, and the sub-mask plate includes an edge region where no pixel pattern is provided, and the baffle plate and the edge region of the sub-mask plate adjacent thereto partially overlap.

[0010] Exemplarily, a virtual pixel pattern is provided on the baffle plate, and the virtual pixel pattern is configured not to penetrate the opposite two surfaces of the baffle plate.

[0011] Exemplarily, the thickness difference between the baffle plate and the sub-mask plate is within a threshold, and no pattern is provided on the baffle plate.

[0012] Exemplarily, N sub-mask plates are configured to form corresponding pixel patterns on the mother board through the same evaporation process; wherein the N sub-mask plates are spliced in sequence along the long side extension direction, and there is a gap between adjacent two sub-mask plates.

[0013] Exemplarily, the pixel pitch of the pixel pattern along the long side extension direction is rib, each sub-mask plate includes a first side and a second side opposite to each other along the long side extension direction of the sub-mask plate, the first side has a first edge region where no pixel pattern is provided, the first edge region has a width b1 along the long side extension direction, the second side has a second edge region where no pixel pattern is provided, the second edge region has a width b2 along the long side extension direction, and the gap has a width c along the long side extension direction; wherein, rib = b1 + b2 + c.

[0014] In a second aspect, an embodiment of the present disclosure provides a method for manufacturing a display substrate, using the evaporation mask plate assembly as described above to manufacture the display substrate, the method including:

[0015] Providing a mother board, wherein the mother board has a long side and a short side, the mother board includes an evaporation effective area, at least one single screen area with an extension length along the long side extension direction is provided in the evaporation effective area, and the evaporation effective area is divided into N sub-evaporation areas along the long side extension direction, N is a positive integer greater than or equal to 2;

[0016] Using the evaporation mask template assembly, an evaporation pixel pattern is formed on the mother board, where the evaporation mask template assembly includes: N sub-mask templates, the sub-mask templates are stretched along the short side extension direction, and the pixel pattern of one sub-mask template corresponds to the pixel pattern of one sub-evaporation area. The pixel patterns of the N sub-mask templates are spliced and combined to form the pixel pattern of the entire evaporation effective area.

[0017] Exemplarily, the step of using the evaporation mask template assembly to form an evaporation pixel pattern on the mother board specifically includes:

[0018] Using M mask template units, through M evaporation processes, corresponding pixel patterns are sequentially formed on the mother board, where one mask template unit corresponds to a single evaporation process.

[0019] Exemplarily, the step of using the evaporation mask template assembly to form an evaporation pixel pattern on the mother board specifically includes:

[0020] Using N sub-mask templates, through one evaporation process, corresponding pixel patterns are formed on the mother board.

[0021] The beneficial effects brought by the embodiments of the present disclosure are as follows:

[0022] In the evaporation mask template assembly and the manufacturing method of the display substrate according to the embodiments of the present disclosure, by dividing the evaporation effective area on the mother board into N sub-evaporation areas arranged in sequence along the long side extension direction, the evaporation mask template assembly is provided with N sub-mask templates, and each sub-mask template is stretched along the short side direction of the mother board. The pixel pattern of one sub-mask template corresponds to the pixel pattern of one sub-evaporation area. The pixel patterns of the N sub-mask templates are spliced and combined to form the pixel pattern of the entire evaporation effective area.

[0023] In this way, the pixel patterns of the N sub-mask templates correspond to different areas on the mother board, which is equivalent to splicing the pixel patterns of the evaporation effective area on the mother board. Therefore, regardless of the size of a single single-screen area on the mother board, the pixel pattern on the single-screen area can be jointly spliced by the pixel patterns of at least two sub-mask templates.

[0024] For example, when the size of the single-screen area is large, the length direction of the single-screen area can be arranged along the long side direction of the mother board for film placement. In the length direction of the single-screen area, the pixel pattern on the single-screen area can be completed by splicing the pixel patterns of at least two sub-masks. For each of the sub-masks, the screen can be stretched along the short side direction of the mother board, and there is no limit to the width of each sub-mask in the long side direction of the mother board. There is no need to stretch the screen along the long side direction of the mother board, avoiding problems such as high transformation cost, large screen stretching difficulty, and poor accuracy caused by stretching the screen in the long side direction, and can meet the requirements of various film placement methods on the mother board.

[0025] Moreover, for an extra-large single screen, such as a single screen with an effective display area exceeding the short side of the mother board, the single screen can be arranged along the long side of the mother board, while the sub-mask is arranged along the short side of the mother board, and the pixel patterns of multiple sub-masks are spliced and combined to form the pixel pattern of the single screen, realizing the evaporation process of large-size and extra-large-size display products. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 One of the schematic diagrams showing the film placement method on the mother board;

[0027] Figure 2 One of the schematic diagrams showing the film placement method on the mother board;

[0028] Figure 3 One of the schematic diagrams showing the film placement method on the mother board;

[0029] Figure 4 One of the schematic diagrams showing the film placement method on the mother board;

[0030] Figure 5 One of the schematic diagrams showing the structure of the first mask unit in the evaporation mask assembly according to some embodiments of the present disclosure;

[0031] Figure 6 One of the schematic diagrams showing the structure of the first mask unit in the evaporation mask assembly according to some embodiments of the present disclosure;

[0032] Figure 7 One of the schematic diagrams showing the structure of the second mask unit in the evaporation mask assembly according to some embodiments of the present disclosure;

[0033] Figure 8 One of the schematic diagrams showing the positional relationship between the sub-mask and the baffle in the evaporation mask assembly according to some embodiments of the present disclosure;

[0034] Figure 9 One of the schematic diagrams showing the splicing position of two sub-masks in the evaporation mask assembly according to other embodiments of the present disclosure, where (b) is an enlarged structural diagram of the local area Q of the splicing position of the two sub-masks in (a);

[0035] Figure 10 It shows a schematic structural diagram of an evaporation mask template assembly in some other embodiments of the present disclosure. Specific embodiments

[0036] To make the objectives, technical solutions, and advantages of the embodiments of the present disclosure clearer, the technical solutions of the embodiments of the present disclosure will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present disclosure. Obviously, the described embodiments are some, but not all, of the embodiments of the present disclosure. All other embodiments obtained by those of ordinary skill in the art based on the described embodiments of the present disclosure without creative efforts shall fall within the scope of protection of the present disclosure.

[0037] Unless otherwise defined, the technical terms or scientific terms used in the present disclosure shall have the ordinary meanings understood by those of ordinary skill in the art to which the present disclosure pertains. The "first", "second", and similar terms used in the present disclosure do not denote any order, quantity, or importance, but are only used to distinguish different components. Similarly, the terms such as "a", "an", or "the" do not denote a limitation of quantity, but mean that there is at least one. The terms such as "including" or "comprising" mean that the elements or items appearing before the term cover the elements or items listed after the term 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", and "right" 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.

[0038] The features such as "parallel", "perpendicular", and "identical" used in the embodiments of the present disclosure include the strict meanings of "parallel", "perpendicular", "identical", etc., as well as the cases with certain tolerances such as "substantially parallel", "substantially perpendicular", and "substantially identical". Considering the measurement and tolerances associated with the measurement of specific quantities (e.g., limitations of the measurement system), it means within the acceptable deviation range for a specific value determined by those of ordinary skill in the art. For example, "substantially" can mean within one or more standard deviations, or within 3% or 5% of the value.

[0039] In addition, in this document, unless otherwise defined, the terms "substantially", "essentially", "about", and "approximately" are used to describe and explain small changes. When used in connection with an event or situation, these terms can cover the exact occurrence of the event or situation, or can also cover the approximate occurrence of the event or situation. For example, when used in connection with a numerical value, these terms can include a range of change of less than or equal to 10% of the numerical value, such as less than or equal to ±5%, less than or equal to ±4%, less than or equal to ±3%, less than or equal to ±2%, less than or equal to ±1%, less than or equal to ±0.5%, less than or equal to ±0.1%, less than or equal to ±0.05%. The term "substantially coplanar" can mean that two surfaces are arranged in the same plane within the range of micrometers, for example, arranged in the same plane within 40μm, 30μm, 20μm, 10μm, or 1μm.

[0040] It should be understood that in the exemplary embodiments of the present disclosure, when a layer or element is referred to as being on another layer or substrate, it may be that the layer or element is directly on the other layer or substrate, or there may be an intermediate layer between the layer or element and the other layer or substrate. "A and B are arranged on the same layer" means that after A and B are formed into a film layer for forming a specific pattern by the same film formation process, the layer structure formed by one patterning process using the same mask.

[0041] Before the method for manufacturing the evaporation mask assembly and the display substrate provided by the embodiments of the present disclosure is described in detail, the related technologies are described as follows:

[0042] With the popularization of AMOLED (Active Matrix Organic Light Emitting Diode) technology in small and medium-sized display products, the incremental market gradually tends to the direction of large and medium-sized display products, such as Notebook and in-vehicle display screens, etc. The evaporation technology is a key step in the manufacturing process of AMOLED display screens, which is used to form a thin film of organic light-emitting materials. However, in the evaporation process of the related technologies, there are problems such as limited number of film arrangements on the mother board when making large-sized screens.

[0043] The applicant of the present disclosure has found through research that one of the reasons for the above problems is:

[0044] In the evaporation process of the AMOLED display panel, it is necessary to use an FMM Mask (Fine Metal Mask) to evaporate and deposit the organic light-emitting materials on the mother board to form a pixel pattern on the mother board. The mother board includes a plurality of single-screen areas, and a plurality of single screens can be obtained after the mother board is cut.

[0045] The FMM Mask (Fine Metal Mask) is to make an opening pattern corresponding to the pixel pattern on an alloy plate, and the strip-shaped FMM Mask is welded onto the mask frame one by one. The mask frame serves to fix the FMM Mask and the fixtures used in the equipment.

[0046] Generally speaking, the mother board has a short side and a long side. Correspondingly, the mask frame also has corresponding short and long sides. In the related art, the FMM Mask generally adopts the screen stretching method in the short side direction, that is, the long side of the strip-shaped FMM Mask is stretched along the short side of the mask frame.

[0047] Taking the AMOLED display product with RGB side by side (true RGB patterning) as an example, during evaporation coating, the effective evaporation coating area on the mother board is basically determined, and the adjustable space of the effective evaporation coating area is very small. Therefore, the number of pieces arranged on the mother board for some specific size products will be limited by this.

[0048] For example, Figure 1 The figure shows the schematic diagram of the piece arrangement of some products on the mother board. As Figure 1 shown, if the mask 1 is arranged according to the screen stretching method in the short side direction, only 6 pcs (that is, 6 single screen areas 3) can be arranged on the mother board 2. As Figure 2 shown, if the mask 1 is stretched in the long side direction, the number of pieces arranged on the mother board 2 can be increased to 8 pcs (that is, 8 single screen areas 3), and the benefit improvement is very obvious.

[0049] In addition, in the case where the effective display area of a single screen is greater than the length of the short side of the effective evaporation coating area of the mother board, according to the screen stretching method in the related art, the screen stretching process of such products cannot be realized. For example, Figure 3 The figure shows the schematic diagram of the piece arrangement of a large-size single screen on the mother board during the evaporation coating process. As Figure 4 shown, when the single screen area is stretched along the short side of the mother board, the effective display area of the single screen area obviously exceeds the effective evaporation coating area of the mother board in the short side direction.

[0050] It can be seen that according to the screen stretching method in the short side direction in the related art, the number of pieces arranged on the mother board will decrease, and even for extra-large size single screens, the existing equipment and process conditions cannot realize the screen stretching process of such products.

[0051] In related technologies, to solve the above problems, the existing equipment is modified to perform long-side tension netting. However, when using long-side tension netting, the following problems exist: First, the cost of modifying the production line equipment after it is determined is very high; second, the difficulty of long-side tension netting is increased compared to short-side tension netting; third, in the case of long-side tension netting, the length of the FMM Mask is correspondingly larger, and it is difficult to guarantee the tension netting accuracy. In addition, for ultra-large-size display products, whether it is short-side tension netting or long-side tension netting, the tension netting process for such ultra-large-size display products cannot be achieved, resulting in limited production sizes of display products.

[0052] To solve at least one of the above technical problems, an evaporation mask template assembly and a manufacturing method of a display substrate are provided in an embodiment of the present disclosure.

[0053] The evaporation mask template assembly provided in the embodiment of the present disclosure is used to evaporate and form pixel patterns on a mother board. As Figures 5 to 7 and Figure 10 shown, the mother board 100 has a long side 110 and a short side 120, the mother board 100 includes an evaporation effective area 100A, at least one single-screen area B with an extension length along the extension direction of the long side 110 is provided in the evaporation effective area 100A, and the evaporation effective area 100A is divided into N sub-evaporation areas C along the extension direction of the long side 110, where N is a positive integer greater than or equal to 2.

[0054] The evaporation mask template assembly 200 includes: N sub-mask templates 210, the sub-mask templates 210 are tensioned along the extension direction of the short side 120, and the pixel pattern of one sub-mask template 210 corresponds to the pixel pattern of one sub-evaporation area C, and the pixel patterns of the N sub-mask templates 210 are spliced and combined to form the pixel pattern of the entire evaporation effective area 100A.

[0055] It should be noted that the pixel pattern on the sub-mask template 210 refers to the opening pattern formed on the sub-mask template 210; the pixel pattern on the mother board 100 refers to the pattern of the organic material layer on each pixel. During evaporation, only the opening pattern on the sub-mask template 210 allows the organic material to pass through, so that the organic light-emitting material is deposited on the mother board 100 to form the pixel pattern on the mother board 100.

[0056] In the above solution, the evaporation effective area 100A of the mother board 100 is divided into N sub-evaporation areas C, the evaporation mask template assembly 200 is provided with N sub-mask templates 210, the pixel pattern of one sub-evaporation area C can correspond to the pattern of one sub-mask template 210, and the pixel patterns of the N sub-mask templates 210 are spliced and combined to form the pixel pattern of the entire evaporation effective area 100A.

[0057] In this way, the pixel patterns of the N sub-masks 210 correspond to different regions on the master plate 100, which is equivalent to splicing the pixel patterns of the evaporation effective region 100A on the master plate 100. Thus, regardless of the size of a single single-screen region B on the master plate 100, the pixel pattern on the single-screen region B can be formed by splicing the pixel patterns of at least two sub-masks 210 together.

[0058] For example, when the size of the single-screen region B is large, the length direction of the single-screen region B can be arranged along the long side 110 direction of the master plate 100 for layout. The evaporation effective region 100A on the master plate 100 is divided into N sub-evaporation regions C. In other words, the unit screen is divided into at least two sub-evaporation regions C in the length direction of the master plate 100. Therefore, in the length direction of the single-screen region B, the pixel pattern on the single-screen region B can be completed by splicing the pixel patterns of at least two sub-masks 210. For each sub-mask 210, the mesh can be set along the short side 120 direction of the master plate 100, and the width in the long side 110 direction of the master plate 100 can be relatively narrow without limitation. Therefore, the mesh setting method of each sub-mask 210 can achieve mesh setting along the short side 120, with reduced mesh setting difficulty, high mesh setting accuracy, low mesh setting transformation cost, and can meet the requirements of various layout methods on the master plate 100.

[0059] Moreover, for an extra-large single screen, such as a single screen with an effective display area exceeding the short side 120 of the master plate 100, the single screen can be arranged along the long side 110 of the master plate 100, while the sub-mask 210 is arranged along the short side 120 of the master plate 100. The pixel patterns of multiple sub-masks 210 are spliced and combined to form the pixel pattern of the single screen, realizing the evaporation process for large-size and extra-large-size display products.

[0060] In some embodiments, as Figure 5 、 Figure 6 and Figure 7 shown, the evaporation mask assembly 200 includes M mask units 201, where M is a positive integer greater than or equal to 2. Among them, the M mask units 201 are configured such that the M mask units 201 form corresponding pixel patterns on the master plate 100 through M evaporation processes in sequence, and one mask unit 201 corresponds to a single evaporation process.

[0061] In the above solution, among the M mask units 201, each mask unit 201 forms a corresponding pixel pattern on the master plate 100 through a single evaporation process. In this way, after the M mask units 201 complete their respective corresponding evaporation processes in sequence, the pixel pattern on the entire master plate 100 can be spliced and formed on the master plate 100.

[0062] Specifically, since each of the mask template units 201 can perform an evaporation process independently, at least one of the sub-mask templates 210 can be included in each of the mask template units 201. As shown in the figure, exemplarily, each of the mask template units 201 further includes: at least one baffle plate 220, wherein, in the same mask template unit 201, the sub-mask template 210 and the baffle plate 220 are configured to be alternately arranged in sequence along the extension direction of the long side 110, that is to say, the sub-evaporation areas C corresponding to the sub-mask templates 210 in the same mask template unit 201 are arranged at intervals; the sub-evaporation areas C corresponding to the sub-mask templates 210 in different mask template units 201 are configured to be alternately arranged along the extension direction of the long side 110, that is to say, the sub-evaporation area C corresponding to the sub-mask template 210 in any one of the mask template units 201 is the sub-evaporation area C corresponding to the baffle plate 220 in another mask template unit 201, so that the pixel patterns in different mask template units 201 correspond to the pixel patterns in different sub-evaporation areas C on the mother board 100, and finally the pixel patterns of the M mask template units 201 are spliced and combined into the pixel pattern of the evaporation effective area 100A on the entire mother board 100.

[0063] Figure 5 The figure shows a schematic diagram during the first evaporation when a plurality of single-screen areas B are arranged on the mother board 100; Figure 6 and Figure 7 The figure shows a schematic diagram during the first evaporation and the second evaporation when only one large-sized single-screen area B is arranged on the mother board 100.

[0064] Taking Figures 5 to 7 the embodiment shown as an example, the length direction of at least one single-screen area B is arranged along the long side 110 direction of the mother board 100 for row placement, and the single-screen area B is divided into a first sub-evaporation area C1, a second sub-evaporation area C2, a third sub-evaporation area C3, and a fourth sub-evaporation area C4 along the long side 110 direction of the mother board 100. The evaporation mask template assembly 200 includes a first mask template unit 2011 and a second mask template unit 2012; wherein,

[0065] The first mask template unit 2011 includes a first sub-mask template 211, a first baffle plate 221, a second sub-mask template 212, and a second baffle plate 222. The mask pattern of the first sub-mask template 211 corresponds to the first sub-evaporation area C1, the mask pattern of the second sub-mask template 212 corresponds to the third sub-evaporation area C3, the mask pattern of the first baffle plate 221 corresponds to the second sub-evaporation area C2, and the mask pattern of the second baffle plate 222 corresponds to the fourth sub-evaporation area C4;

[0066] The second mask template unit 2012 includes a third sub-mask template 213, a third baffle 223, a fourth sub-mask template 214, and a fourth baffle 224. The mask pattern of the third sub-mask template 213 corresponds to the second sub-evaporation region C2, the mask pattern of the fourth sub-mask template 214 corresponds to the fourth sub-evaporation region C4, the mask pattern of the third baffle 223 corresponds to the first sub-evaporation region C1, and the mask pattern of the fourth baffle 224 corresponds to the third sub-evaporation region C3.

[0067] When performing evaporation, the first evaporation process can be carried out through the first mask template unit 2011. At this time, the first baffle 221 and the second baffle 222 respectively block the second sub-evaporation region C2 and the fourth sub-evaporation region C4. Using the first sub-mask template 211 and the second sub-mask template 212, pixel patterns of the first sub-evaporation region C1 and the third sub-evaporation region C3 are formed on the mother board 100; then, the second evaporation process is carried out through the second mask template unit 2012. At this time, the third baffle 223 and the fourth baffle 224 respectively block the first sub-evaporation region C1 and the third sub-evaporation region C3. Using the third sub-mask template 213 and the fourth sub-mask template 214, pixel patterns of the second sub-evaporation region C2 and the fourth sub-evaporation region C4 are formed on the mother board 100. In this way, through two evaporation processes, the pixel pattern evaporation of the same organic light-emitting layer on the mother board 100 is realized.

[0068] There can be various ways to divide the sub-evaporation regions C on the mother board 100, and the number of pixels in each sub-evaporation region C can be the same or different. For example, taking a specific exemplary embodiment as an example, the resolution of the bar single-screen area B in the length direction is 4000. Taking the long side 110 direction of the mother board 100 as the row direction of the pixel pattern and the short side 120 direction of the mother board 100 as the column direction of the pixel pattern, the pixel pattern of the first sub-evaporation region C1 can be the pixels in columns 0 to 1000, the pixel pattern of the second sub-evaporation region C2 can be the pixels in columns 1001 to 2000, the pixel pattern of the third sub-evaporation region C3 can be the pixels in columns 2001 to 3000, and the pixel pattern of the fourth sub-evaporation region C4 can be the pixels in columns 3001 to 4000. The above is only an example, but not limited thereto.

[0069] In addition, in some exemplary embodiments, in the same mask template unit 201, at least one of the baffles 220 and at least one of the sub-mask templates 210 adjacent thereto are connected as an integral structure. In other words, at least one of the sub-mask templates 210 in the mask template unit 201 can be made on the same mask as the baffle 220.

[0070] In this way, since the evaporation mask template needs to be attached to the mother board 100 under the action of magnetic force or the like during evaporation coating, the sub-mask template 210 and the shielding board 220 are integrally manufactured, which can ensure that the shielding board 220 and the sub-mask template 210 are made of the same material and have the same or slightly different thicknesses, so that the stress, magnetic force, etc. received by the shielding board 220 and the sub-mask template 210 are as consistent as possible, so as to ensure that the sag amount of the first mask unit 2011 can be controlled within the allowable range.

[0071] However, when the sub-mask template 210 and the shielding board 220 are integrally manufactured, the width of the integrated board formed by the sub-mask template 210 and the shielding board 220 in the long side 110 direction of the mother board 100 may be relatively large, which is not conducive to the mesh tension accuracy, mesh tension difficulty, etc. Therefore, in some exemplary embodiments, as Figure 8 shown, in the same mask unit 201, at least one shielding board 220 and at least one sub-mask template 210 adjacent thereto are separately arranged, and at least one shielding board 220 and at least one sub-mask template 210 adjacent thereto are stacked, wherein each sub-mask template 210 includes an intermediate area where pixel patterns are provided and an edge area where no pixel patterns are provided, and the edge area is located on opposite sides of the intermediate area along the long side 110 direction of the mother board 100, and a part of the edge area of the shielding board 220 and the adjacent sub-mask template 210 overlaps.

[0072] Adopting the above scheme, the shielding board 220 and the sub-mask template 210 are separately stacked, which is beneficial to reducing the width of each sub-mask template 210, realizing the narrow-width design of the sub-mask template 210, and further beneficial to ensuring the mesh tension accuracy of the entire mask template and reducing the mesh tension difficulty. Moreover, each sub-mask template 210 has an edge area where no pixel patterns are provided, and the edge area can keep a certain distance between the shielding board 220 and the pixel pattern closest to the edge area, so as to avoid problems such as shadows on the pixel pattern due to the presence of the shielding board 220.

[0073] In addition, in order to ensure that the stress, magnetic force, etc. received by the shielding board 220 and the sub-mask template 210 are substantially the same, so as to ensure that the sag amount of the entire mask template is within the allowable range, in some exemplary embodiments, the shielding board 220 may be provided with virtual pixel patterns 220a, and the virtual pixel patterns 220a are configured not to penetrate the opposite two surfaces of the shielding board 220.

[0074] The pixel pattern may be an opening pattern obtained by double-sided etching of the sub-mask 210, while the virtual pixel pattern 220a may be a groove structure obtained by one-sided semi-etching treatment of the mask 220. In this way, the stress conditions of the sub-mask 210 and the mask 220 can be ensured to be consistent as much as possible.

[0075] In addition, the pixel arrangement of the virtual pixel pattern 220a and the pixel pattern may be substantially the same. For example, the size of a single pixel pattern, the pixel pitch, etc. may be the same. However, this is not a limitation.

[0076] In addition, in the above solution, a virtual pixel pattern 220a is provided on the mask 220 to ensure that the stress conditions of the sub-mask 210 and the mask 220 are consistent as much as possible. However, in some other exemplary embodiments, the thickness difference between the mask 220 and the sub-mask 210 is within a threshold, and no pattern may be provided on the mask 220. By reasonably selecting the thickness and material of the mask 220, etc., the stress conditions of the sub-mask 210 and the mask 220 are ensured to be consistent as much as possible.

[0077] In addition, it should be noted that each mask unit 201 may further include a mask frame (not shown in the figure), and each sub-mask 210 and the mask 220 may be welded to the corresponding mask frame by stretching the net.

[0078] In addition, it should also be noted that as Figures 5 to 7 shown, each mask unit 201 may further include a support plate (howling mask) 230, and the support plate 230 is used to support the sub-mask 210 and the mask 220 and define the graphics of the effective display areas of each single-screen area B. For example, Figure 5 shown, 4 effective display areas of the single-screen area B are defined by the support plate 230; Figure 6 and Figure 7 shown, 1 effective display area of the single-screen area B is defined by the support plate 230.

[0079] In some other exemplary embodiments of the present disclosure, as Figure 10 shown, N sub-masks 210 are configured to form corresponding pixel patterns on the mother board 100 through the same evaporation process. Among them, the N sub-masks 210 are spliced in sequence along the extension direction of the long side 110, and there is a gap E between adjacent two sub-masks 210.

[0080] In the above solution, N of the sub-masks 210 can be directly spliced into a mask, and by arranging and splicing the N sub-masks 210 in sequence along the long side 110 direction of the mother board 100, the entire evaporation effective area 100A on the mother board 100 can be fully covered. In this way, the evaporation of the same organic light-emitting layer on the mother board 100 can be achieved through one evaporation process.

[0081] By directly splicing N of the sub-masks 210 into a mask and completing the evaporation of the same organic light-emitting layer on the mother board 100 through one evaporation process, compared with the solution in the above embodiment where N of the sub-masks 210 and the baffle 220 are made into two mask units 201 and at least two evaporation processes are used to complete the evaporation of the same organic light-emitting layer on the mother board 100, if two evaporations are used for the same organic light-emitting layer, film thickness differences may be caused by different evaporation processes, and further color differences in the same color pixels may occur. However, by completing the evaporation of the same organic light-emitting layer on the mother board 100 through one evaporation process, the above color differences can be avoided.

[0082] It should be noted that when at least two evaporation processes are used to complete the evaporation of the same organic light-emitting layer on the mother board 100, although film thickness differences and further color differences in the same color pixels may be caused by different evaporation processes, the above differences can be compensated by a later algorithm.

[0083] Demura technology is an algorithm for display calibration and color management. Its main purpose is to compensate for color differences between different pixels, thereby improving the overall color consistency and accuracy of the display. Demura technology generally involves the following aspects: 1) Gamut mapping: First, determine the gamut characteristics of the display, such as the range of colors that can be displayed, and establish a color space model. This can be achieved by measuring the display and analyzing the relationship between its input and output. 2) Color compensation: Adjust the original input signal through an algorithm to compensate for the color deviation of specific pixels. This usually requires calculating using the RGB values of each pixel to ensure that the output of each pixel can be as close as possible to the set target color standard. 3) Nonlinear correction: Since the response characteristics of the display are often nonlinear, Demura technology can use various nonlinear algorithms (e.g., progressive functions) to adjust the color output to make it more in line with expectations. 4) Dynamic adjustment: During operation, the output of the display can be monitored in real time, and dynamic color adjustment can be performed according to the actual output results to ensure the stability of the visual effect. 5) Visual matching: Adjust according to the human eye's perception characteristics of colors. For example, compensate for the human eye's sensitivity to light of different wavelengths to achieve a more natural color presentation.

[0084] Therefore, in some embodiments, the evaporation coating process is adopted at least twice to complete the evaporation coating of the same layer of the organic light-emitting layer on the mother board 100, and the resulting color difference can be compensated by an algorithm using the Demura technology. However, it is not limited thereto.

[0085] It should be noted that the method of directly splicing the N sub-mask plates 210 into a mask plate in this embodiment is applicable to products with a relatively low pixel density PPI. For example, for a large-size display screen, the PPI is generally low, the pixel pitch rib is large, and the mask plate has the characteristic of shrinking after being stretched and meshed. Therefore, the widths of the first edge region and the second edge region on the sub-mask plate 210 are reduced, for example, only a width of 0.5*a is reserved, where rib is the pixel pitch.

[0086] In addition, in the method of directly splicing the N sub-mask plates 210 into a mask plate in this embodiment, there are edge regions where pixel patterns are not set on any of the sub-mask plates 210, and there is a gap E between adjacent sub-mask plates 210. The sizes of the edge regions and the gap E need to be small to meet the pixel pitch size requirements of the pixel patterns on the mother board 100.

[0087] In addition, at the splicing position of adjacent sub-mask plates 210, a certain gap E can be reserved as much as possible between the two sub-mask plates 210. The size of the gap E can be determined according to the pixel resolution ppi, the pixel pitch rib, and the accuracy of the width of the sub-mask plate 210 of the actual product.

[0088] For example, in some exemplary embodiments, as Figure 9 shown, the pixel pitch of the pixel pattern in the extending direction of the long side 110 is rib. Each sub-mask plate 210 includes a first side and a second side opposite to each other in the extending direction of the long side 110 of the sub-mask plate 210. The first side has a first edge region 210a where the pixel pattern is not set, and the first edge region 210a has a width b1 in the extending direction of the long side 110. The second side has a second edge region 210b where the pixel pattern is not set, and the second edge region 210b has a width b2 in the extending direction of the long side 110. The gap E has a width c in the extending direction of the long side 110. Wherein, rib = b1 + b2 + c. In this way, it can be ensured that the pixel patterns at the splicing position are the same as those at other positions.

[0089] For example, taking a display product with 254 ppi as an example, the pixel pitch is 100 μm. In the case of a real RGB arrangement, the pixel pitch rib is about 45 μm, that is, the sum of the width of the gap E and the widths of the first edge region 210a and the second edge region is equal to 45 μm.

[0090] If the incoming material width accuracy of the mask is relatively high, for example, the accuracy of the mask is controlled within 5 μm, then a gap E of 10 μm can be reserved between the two sub-masks 210, so that it can prevent the two sub-masks 210 from overlapping due to fluctuations during the process.

[0091] In addition, it should be noted that although due to the existence of the gap E and the gap E being within the effective display area, some organic light-emitting materials will be evaporated onto the mother board 100 through the gap E, however, during the later encapsulation of the effective display area, the encapsulation is performed for the entire effective display area. Therefore, the organic light-emitting materials evaporated at the gap E will also be encapsulated, and there will be no risk of water vapor erosion or the like.

[0092] In addition, the embodiments of the present disclosure provide a method for manufacturing a display substrate. Using the evaporation mask assembly 200 provided by the embodiments of the present disclosure to manufacture the display substrate, the method includes:

[0093] Step S01: Provide a mother board 100, where the mother board 100 has a long side 110 and a short side 120, the mother board 100 includes an evaporation effective area 100A, at least one single screen area B with an extension length along the extension direction of the long side 110 is provided in the evaporation effective area 100A, and the evaporation effective area 100A is divided into N sub-evaporation areas C along the extension direction of the long side 110, and N is a positive integer greater than or equal to 2;

[0094] Step S02: Use the evaporation mask assembly 200 to evaporate and form a pixel pattern on the mother board 100, where the evaporation mask assembly 200 includes: N sub-masks 210, the sub-masks 210 are stretched along the extension direction of the short side 120, and the pixel pattern of one sub-mask 210 corresponds to the pixel pattern of one sub-evaporation area C, and the pixel patterns of the N sub-masks 210 are spliced and combined to form the pixel pattern of the entire evaporation effective area 100A.

[0095] Exemplarily, when the evaporation mask assembly 200 includes M mask units 201, the above step S02 specifically includes:

[0096] Use the M mask units 201 to form corresponding pixel patterns on the mother board 100 through M evaporation processes in sequence, where one mask unit 201 corresponds to a single evaporation process.

[0097] Exemplarily, when the N sub-masks 210 in the evaporation mask assembly 200 are spliced in sequence along the extension direction of the long side 110, the above step S02 specifically includes:

[0098] Using the N sub-masks 210, a corresponding pixel pattern is formed on the mother board 100 through a single evaporation process.

[0099] Since the principle of the problem solved by the manufacturing method of this display substrate is similar to the principle of the problem solved by the above evaporation mask assembly 200, therefore, for the embodiments of the manufacturing method of the display substrate provided in this disclosure, reference can be made to the embodiments of the above evaporation mask assembly 200 provided in the embodiments of this disclosure, which will not be elaborated here.

[0100] The following points need to be noted:

[0101] (1) The drawings of the embodiments of this disclosure only relate to the structures involved in the embodiments of this disclosure, and other structures can refer to the general design.

[0102] (2) For clarity, in the drawings used to describe the embodiments of this disclosure, the thickness of layers or regions is enlarged or reduced, that is, these drawings are not drawn to actual scale. It can be understood that when an element such as a layer, film, region, or substrate is referred to as being "on" or "under" another element, the element can be "directly" on or under the other element or there can be intermediate elements.

[0103] (3) Without conflict, the embodiments of this disclosure and the features in the embodiments can be combined with each other to obtain new embodiments.

[0104] The above is only the specific implementation manner of this disclosure, but the protection scope of this disclosure is not limited thereto. The protection scope of this disclosure should be subject to the protection scope of the claims.

Claims

1. A vapor deposition mask assembly, characterized in that: Used to form a pixel pattern on a motherboard by evaporation, the motherboard having a long side and a short side, the motherboard comprising an evaporation effective area, the evaporation effective area is provided with at least one single screen area having an extension length along the extension direction of the long side, and the evaporation effective area is divided into N sub-evaporation areas along the extension direction of the long side, N is a positive integer greater than or equal to 2; The evaporation mask template assembly includes: N sub-mask templates, the sub-mask templates are stretched along the extension direction of the short side, and the pixel pattern of one of the sub-mask templates corresponds to the pixel pattern of one of the sub-evaporation areas, and the pixel patterns of the N sub-mask templates are spliced ​​and combined to form the pixel pattern of the entire evaporation effective area.

2. The evaporation mask assembly according to claim 1, characterized in that: The evaporation mask template assembly includes M mask template units, where M is a positive integer greater than or equal to 2; the M mask template units are configured as follows: the M mask template units sequentially form corresponding pixel patterns on the motherboard through M evaporation processes, and one mask template unit corresponds to a single evaporation process; Among them, each of the mask template units includes: at least one sub-mask template and at least one baffle plate, wherein, in the same mask template unit, the sub-mask template and the baffle plate are configured to be arranged alternately in sequence along the long side extension direction; the sub-evaporation areas corresponding to the sub-masks in different mask template units are configured to be arranged alternately along the long side extension direction.

3. The evaporation mask assembly according to claim 2, characterized in that: In the same mask template unit, at least one of the baffle plates and at least one of the adjacent sub-mask templates are connected to form an integral structure; or, at least one of the baffle plates and at least one of the adjacent sub-mask templates are stacked, and the sub-mask template includes an edge area where a pixel pattern is not set, and the baffle plate and the edge area of ​​the adjacent sub-mask template partially overlap.

4. The evaporation mask assembly according to claim 2, characterized in that: A virtual pixel pattern is disposed on the shielding plate, and the virtual pixel pattern is configured not to penetrate through two opposite surfaces of the shielding plate.

5. The evaporation mask assembly according to claim 2, characterized in that: A thickness difference between the shielding plate and the sub-mask plate is within a threshold, and no pattern is set on the shielding plate.

6. The evaporation mask assembly according to claim 1, characterized in that: The N sub-masks are configured to form corresponding pixel patterns on the motherboard through the same evaporation process; The N sub-mask plates are sequentially arranged and spliced ​​along the extending direction of the long sides, and there is a gap between two adjacent sub-mask plates.

7. The evaporation mask assembly according to claim 6, characterized in that: The pixel interval of the pixel pattern along the direction in which the long side extends is rib, and each of the sub-mask templates includes a first side and a second side opposite to the sub-mask template along the direction in which the long side extends, the first side having a first edge area where the pixel pattern is not set, and the first edge area has a width b1 along the direction in which the long side extends, the second side having a second edge area where the pixel pattern is not set, and the second edge area has a width b2 along the direction in which the long side extends, and the gap has a width c along the direction in which the long side extends; wherein, rib=b1+b2+c.

8. A method for manufacturing a display substrate, characterized in that: The display substrate is manufactured using the evaporation mask assembly according to any one of claims 1 to 7, the method comprising: A motherboard is provided, wherein the motherboard has a long side and a short side, the motherboard includes an evaporation effective area, at least one single screen area having an extension length along an extension direction of the long side is provided in the evaporation effective area, and the evaporation effective area is divided into N sub-evaporation areas along the extension direction of the long side, where N is a positive integer greater than or equal to 2; The evaporation mask template assembly is used to form a pixel pattern by evaporation on the motherboard, wherein the evaporation mask template assembly includes: N sub-masks, the sub-masks are stretched along the extension direction of the short sides, and the pixel pattern of one sub-mask template corresponds to the pixel pattern of one sub-evaporation area, and the pixel patterns of the N sub-masks are spliced ​​and combined to form the pixel pattern of the entire evaporation effective area.

9. The method according to claim 8, characterized in that When applied to the evaporation mask assembly according to claim 2, the evaporation of the evaporation mask assembly to form a pixel pattern on the motherboard specifically includes: By using M mask template units and performing M evaporation processes, corresponding pixel patterns are sequentially formed on the motherboard, wherein one mask template unit corresponds to a single evaporation process.

10. The method according to claim 8, characterized in that When applied to the evaporation mask plate assembly according to claim 6, the evaporation of the evaporation mask plate assembly to form a pixel pattern on the motherboard specifically includes: By using N sub-masks and undergoing one evaporation process, corresponding pixel patterns are formed on the motherboard.

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