Mask assembly, preparation method and evaporation equipment

Abstract

The invention discloses a mask assembly, a preparation method and evaporation equipment, and belongs to the technical field of display. The mask assembly comprises a mask, and the mask comprises an effective mask area used for being arranged corresponding to a display area of a display substrate. The mask plate comprises an organic material layer which comprises a plurality of mask openings located in the effective mask area and arranged at intervals, and the mask openings are used for being arranged corresponding to areas to be evaporated in the display area; and the magnetic pattern layer is positioned on one side of the organic material layer and is positioned among the mask openings in the effective mask region. The mask opening precision can be improved, so that the evaporation process precision requirement of the display substrate can be met.

Description

Technical Field

[0001] The present application belongs to the field of display technology, and in particular relates to a mask assembly and a preparation method, and an evaporation device. Background Art

[0002] Near-eye display products (such as VR / AR devices) have extremely high requirements for screen display clarity and brightness. Silicon-based OLED has the advantages of ultra-small size, ultra-high pixel density (PPI) and high brightness, which can reduce the "screen door effect" and is highly suitable for new near-eye display scenarios such as VR / AR.

[0003] At present, glass-based OLEDs use a metal mask plate (FMM) and make mask openings through wet etching. The manufacturing accuracy of the mask openings is poor and cannot meet the evaporation process accuracy requirements of silicon-based OLEDs. Summary of the invention

[0004] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, the present application proposes a mask assembly and a preparation method, and an evaporation device, which can improve the mask opening accuracy to meet the evaporation process accuracy requirements of the display substrate.

[0005] In a first aspect, the present application provides a mask assembly, including a mask, wherein the mask includes an effective mask area corresponding to a display area of ​​a display substrate; the mask includes:

[0006] The organic material layer comprises a plurality of mask openings located in the effective mask area and arranged at intervals, wherein the mask openings are used to be arranged corresponding to the areas to be evaporated in the display area;

[0007] The magnetic pattern layer is located on one side of the organic material layer and between the plurality of mask openings in the effective mask area.

[0008] According to the mask plate assembly of the present application, by setting the mask opening in the organic material layer, the size of the mask opening can be accurately controlled, and the accuracy and shape diversity of the mask opening can be improved to meet the accuracy requirements of the evaporation process of the display substrate, and a magnetic pattern layer is set between the mask openings so that the mask plate is tightly fitted to the display substrate under the action of magnetic force, so as to reduce the evaporation shadow when the to-be-evaporated area of ​​the display substrate is evaporated through the mask plate, thereby improving the evaporation effect.

[0009] According to an embodiment of the present application, the magnetic pattern layer is also located outside the effective mask area.

[0010] According to an embodiment of the present application, the magnetic pattern layer is disposed around the mask opening.

[0011] According to an embodiment of the present application, the plurality of mask openings are distributed in multiple rows and columns, and the magnetic pattern layer is located between the mask openings in two adjacent rows and / or two adjacent columns.

[0012] According to one embodiment of the present application, the magnetic pattern layer includes a plurality of patterns located between a plurality of the mask openings;

[0013] A plurality of the patterns are evenly distributed; or,

[0014] In a direction toward the center of the effective mask area, the area and / or density of the pattern gradually increases.

[0015] According to an embodiment of the present application, the spacing between adjacent mask openings is positively correlated with the width of the magnetic pattern layer between adjacent mask openings.

[0016] According to one embodiment of the present application, the mask further includes:

[0017] The first supporting portion is located at a side of the organic material layer away from the magnetic pattern layer and is located outside the effective mask area and is arranged around a peripheral edge of the organic material layer.

[0018] According to an embodiment of the present application, the mask plate includes a plurality of effective mask areas arranged at intervals; the mask plate further includes:

[0019] The second supporting portion is located at a side of the organic material layer away from the magnetic pattern layer and between the plurality of effective mask areas; the height of the second supporting portion is less than or equal to the height of the first supporting portion.

[0020] According to one embodiment of the present application, the mask assembly further includes:

[0021] The mask frame is arranged around the circumference of the mask.

[0022] According to an embodiment of the present application, a longitudinal section of the mask opening is trapezoidal.

[0023] In a second aspect, the present application provides an evaporation device, comprising:

[0024] A carrier, including a carrying surface, for carrying a display substrate;

[0025] A magnetic component, located on a side of the carrier away from the carrying surface;

[0026] The mask assembly as described in the first aspect is located on a side of the carrier close to the carrying surface.

[0027] In a third aspect, the present application provides a method for preparing a mask assembly, wherein the mask assembly includes a mask, and the mask includes an effective mask area for being arranged corresponding to a display area of ​​a display substrate; the method includes:

[0028] forming a magnetic pattern layer;

[0029] forming an organic material layer covering the magnetic pattern layer;

[0030] A plurality of mask openings are formed in the effective mask area of ​​the organic material layer. The mask openings are used to correspond to the areas to be evaporated in the display area. The magnetic pattern layer is located between the plurality of mask openings in the effective mask area.

[0031] According to an embodiment of the present application, before forming a plurality of mask openings spaced apart in the effective mask region of the organic material layer, the method further includes:

[0032] The mask plate is welded to a mask plate frame, and the mask plate frame is arranged around the circumference of the mask plate.

[0033] According to an embodiment of the present application, the mask plate includes a plurality of effective mask areas arranged at intervals; the method further includes:

[0034] Providing a substrate, on which the magnetic pattern layer is formed;

[0035] Before forming a plurality of mask openings spaced apart from each other in the effective mask region of the organic material layer, the method further comprises:

[0036] Attaching a transparent substrate to a side of the organic material layer away from the magnetic pattern layer;

[0037] The substrate is etched into a first supporting portion and a second supporting portion, wherein the first supporting portion is located outside the effective mask area and is arranged around the peripheral edge of the organic material layer, and the second supporting portion is located between a plurality of the effective mask areas; the height of the second supporting portion is less than or equal to the height of the first supporting portion;

[0038] The transparent substrate is removed.

[0039] The above one or more technical solutions in the embodiments of the present application have at least one of the following technical effects:

[0040] By setting a mask opening in the organic material layer, the size of the mask opening can be accurately controlled, the accuracy of the mask opening and the shape diversification can be improved to meet the accuracy requirements of the evaporation process of the display substrate, and a magnetic pattern layer is set between the mask openings so that the mask plate is closely attached to the display substrate under the action of magnetic force, so as to reduce the evaporation shadow when the evaporation area of ​​the display substrate is evaporated through the mask plate, thereby improving the evaporation effect;

[0041] Furthermore, the mask is first combined with the mask frame, and then a mask opening is formed in the organic material layer of the mask, which omits the tedious stretching process, reduces the risk of damage to the mask, improves the position accuracy of the mask opening, greatly reduces the manufacturing difficulty and operating costs, and improves production efficiency.

[0042] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0044] Figure 1 is a top view of a mask assembly provided in an embodiment of the present application;

[0045] Figure 2 This is one of the structural schematic diagrams of the mask assembly provided in the embodiment of the present application;

[0046] Figure 3 This is one of the structural schematic diagrams of the effective mask area in the mask assembly provided in the embodiment of the present application;

[0047] Figure 4 This is the second structural schematic diagram of the effective mask area in the mask assembly provided in the embodiment of the present application;

[0048] Figure 5 This is the third structural schematic diagram of the effective mask area in the mask assembly provided in the embodiment of the present application;

[0049] Figure 6 This is the fourth structural schematic diagram of the effective mask area in the mask assembly provided in the embodiment of the present application;

[0050] Figure 7 This is the fifth structural schematic diagram of the effective mask area in the mask assembly provided in the embodiment of the present application;

[0051] Figure 8 This is the sixth structural schematic diagram of the effective mask area in the mask assembly provided in the embodiment of the present application;

[0052] Fig. 9This is the seventh structural schematic diagram of the effective mask area in the mask assembly provided in the embodiment of the present application;

[0053] Fig.10 is a schematic diagram of the structure of a mask opening in the related art;

[0054] Fig.11 is a schematic structural diagram of a mask opening in a mask plate assembly provided in an embodiment of the present application;

[0055] Fig.12 This is one of the state schematic diagrams of the evaporation device provided in the embodiment of the present application;

[0056] Fig.13 This is the second state schematic diagram of the evaporation device provided in the embodiment of the present application;

[0057] Fig.14 It is a schematic diagram of a process for preparing a mask assembly provided in an embodiment of the present application;

[0058] Fig.15 It is one of the structural schematic diagrams in the method for preparing a mask assembly provided in an embodiment of the present application;

[0059] Fig.16 This is the second structural schematic diagram of the method for preparing a mask assembly provided in an embodiment of the present application;

[0060] Fig.17 This is the third structural schematic diagram of the method for preparing a mask assembly provided in an embodiment of the present application;

[0061] Fig.18 This is the fourth structural schematic diagram of the method for preparing a mask assembly provided in an embodiment of the present application;

[0062] Fig.19 This is the fifth structural schematic diagram of the method for preparing a mask assembly provided in an embodiment of the present application;

[0063] Fig. 20 This is the sixth structural schematic diagram of the method for preparing a mask assembly provided in an embodiment of the present application;

[0064] Fig.21 This is the second structural schematic diagram of the mask assembly provided in the embodiment of the present application. DETAILED DESCRIPTION

[0065] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0066] The following describes the mask assembly, preparation method, and evaporation equipment provided in the embodiments of the present application with reference to the accompanying drawings.

[0067] Figure 1 A schematic structural diagram of a mask assembly provided in an embodiment of the present application.

[0068] like Figure 1 As shown, the mask assembly provided in the embodiment of the present application includes a mask 1. Mask 1 can be a vapor deposition mask, used to evaporate a film layer on a display substrate. Among them, the display substrate can be a silicon-based OLED display substrate. The display substrate includes a display area for image display, and the display area has a plurality of sub-pixel areas arranged regularly. The display area includes an area to be evaporated, and the area to be evaporated can include a sub-pixel area, that is, the display area can include a plurality of areas to be evaporated with a regular arrangement.

[0069] The mask plate 1 includes an effective mask area 11, which is used to be set corresponding to the display area of ​​the display substrate. The size and shape of the effective mask area 11 of the mask plate 1 can match the display area of ​​the display substrate. When the mask plate 1 is used to evaporate a film layer on the display substrate, the effective mask area 11 of the mask plate 1 can overlap with the display area of ​​the display substrate.

[0070] The mask plate 1 may include one or more effective mask areas 11. In the case where the mask plate 1 includes multiple effective mask areas 11, the multiple effective mask areas 11 are arranged at intervals, and are used to correspond to the display areas of multiple display substrates one by one. The size and shape of each mask area 11 and the display area of ​​the corresponding display substrate can match, and the mask plate 1 can be used to evaporate film layers on multiple display substrates at the same time.

[0071] Combination Figure 2 As shown, the mask plate 1 includes an organic material layer 12 and a magnetic pattern layer 13. The organic material layer 12 includes a plurality of mask openings 14, and the mask openings 14 penetrate the organic material layer 12 longitudinally (i.e., in the thickness direction of the organic material layer 12). The plurality of mask openings 14 are located in the effective mask area 11, and the plurality of mask openings 14 are arranged at intervals. The mask openings 14 are used to correspond to the areas to be evaporated (such as sub-pixel areas) in the display area, and the plurality of mask openings 14 can be arranged one-to-one with the plurality of areas to be evaporated (such as multiple sub-pixel areas) in the display area. The transverse cross-section of the mask opening 14 can match the size and shape of the area to be evaporated of the display substrate. As shown Figures 3 to 9 As shown, the transverse cross-section of the mask opening 14 can be circular, square, hexagonal, etc. When the mask 1 is used to evaporate a film layer in the area to be evaporated on the display substrate, the mask opening 14 and the area to be evaporated on the display substrate can overlap. In the case where the area to be evaporated is a sub-pixel area, the film layer evaporated in the area to be evaporated on the display substrate using the mask 1 can include a light-emitting unit.

[0072] The longitudinal cross section of the mask opening 14 may be rectangular or trapezoidal. In the case where the longitudinal cross section of the mask opening 14 is trapezoidal, Figure 2 As shown, the bottom angle α of the mask opening 14 is less than 90°, so as to reduce the shielding of the evaporation material by the mask plate 1 and reduce the color mixing problem caused by the evaporation shadow.

[0073] The organic material layer 12 may include photoresist (PI) etc. The thickness of the organic material layer 12 may be 2-5 um. The thickness of the organic material layer 12 needs to be uniform, for example, the thickness variation of the organic material layer 12 should be kept within 1%.

[0074] The magnetic pattern layer 13 is located on one side of the organic material layer 12. When the mask 1 is used to evaporate a film layer in the to-be-evaporated area of ​​the display substrate, the magnetic pattern layer 13 is located on the side of the organic material layer 12 away from the display substrate. The magnetic pattern layer 13 is located between the multiple mask openings 14 in the effective mask area 11. The magnetic pattern layer 13 can completely cover the organic material layer 12 between the multiple mask openings 14, or can partially cover the organic material layer 12 between the multiple mask openings 14. By adjusting the shape, area and position of the magnetic pattern layer 13 between the multiple mask openings 14, the size and distribution of the magnetic force on the mask can be adjusted.

[0075] The magnetic pattern layer 13 may include one or more combinations of magnetic materials such as aluminum, iron, cobalt, nickel, and tin. The thickness of the magnetic pattern layer 13 may be 0.1-3 um.

[0076] like Fig.10 and Fig.11 As shown, compared with the related art of making mask openings in metal mask plates, this embodiment makes mask openings 14 in the organic material layer 12, which can accurately control the size of the mask openings 14, improve the accuracy and shape diversity of the mask openings 14, so as to meet the precision requirements of the evaporation process of the display substrate with ultra-high PPI. Moreover, the drooping deformation of the organic material layer 12 caused by gravity is smaller, which improves the position accuracy of the mask opening 14. Moreover, a magnetic pattern layer 13 is provided between the mask openings 14, so that the mask plate 1 has magnetic properties, and can be closely attached to the display substrate under the action of magnetic force during the evaporation process, so as to reduce the evaporation shadow when the mask plate is used to evaporate the area to be evaporated on the display substrate, thereby improving the evaporation effect.

[0077] In some embodiments, the magnetic pattern layer 13 is also located outside the effective mask area 11. Figure 2 As shown, the magnetic pattern layer 13 is located outside the effective mask area 11 and between the multiple mask openings 14 in the effective mask area 11. The magnetic pattern layer 13 may cover all areas outside the effective mask area 11, or may cover part of the areas outside the effective mask area 11.

[0078] By adjusting the shape, area, and distribution position of the magnetic pattern layer 13 , the magnitude and distribution of the magnetic force on the mask 1 can be adjusted.

[0079] In some embodiments, the magnetic pattern layer 13 and the organic material layer 12 have the same design, that is, the magnetic pattern layer 13 and the organic material layer 12 overlap exactly, so as to increase the magnetic force on the mask 1 .

[0080] In some embodiments, the magnetic pattern layer 13 is disposed around the mask opening 14. The magnetic pattern layer 13 may be disposed around at least one mask opening 14. In some embodiments, the magnetic pattern layer 13 may be disposed around each mask opening 14. The magnetic pattern layer 13 may include an overall pattern located in the effective mask area 11, and the overall pattern is disposed around each mask opening 14, such as Figure 3 and Figure 4 The magnetic pattern layer 13 may also include a plurality of patterns located in the effective mask area 11, each pattern being arranged around a mask opening 14, and different patterns surround different mask openings 14, such as Figure 5 As shown. The pattern is a closed shape, such as a circular ring or a polygonal ring, etc. The magnetic pattern layer 13 and the mask opening 14 can be arranged at intervals or adjacent to each other, which is not specifically limited here.

[0081] In some embodiments, the plurality of mask openings 14 are distributed in a plurality of rows and columns. The plurality of mask openings 14 may be distributed in an array. Figures 3 to 9 As shown, multiple rows of mask openings 14 may be distributed in an aligned manner, and multiple columns of mask openings 14 may be distributed in an aligned manner; or, two adjacent rows of mask openings 14 may be distributed in an alternating manner, and two adjacent columns of mask openings 14 may be distributed in an alternating manner.

[0082] The magnetic pattern layer 13 may be located between two adjacent rows of mask openings 14. Figure 6 As shown, the magnetic pattern layer 13 may include a plurality of patterns, each pattern extending in the row direction, and a pattern is provided between every two rows of mask openings 14. The magnetic pattern layer 13 may also surround between two adjacent columns of mask openings 14. For example, the magnetic pattern layer 13 may include a plurality of patterns, each pattern extending in the column direction, and a pattern is provided between every two columns of mask openings 14. The magnetic pattern layer 13 may also be located between two adjacent rows of mask openings 14 and between two adjacent columns of mask openings 14, and extend in the row direction and the column direction respectively to surround each mask opening 14.

[0083] In some embodiments, the magnetic pattern layer 13 includes a plurality of patterns located between the plurality of mask openings 14, and the plurality of patterns are spaced apart. The pattern may be circular or square, etc. The shapes of the plurality of patterns may be the same or different. The area sizes of the plurality of patterns may be the same or different.

[0084] In some embodiments, Figure 7 and Figure 8 As shown, the plurality of patterns may be uniformly distributed among the plurality of mask openings 14 in the effective mask area 11 .

[0085] In some embodiments, the area and / or density of the pattern may gradually increase in the direction toward the center of the effective mask area 11. For example, when the density of the pattern remains unchanged, the area of ​​the pattern may gradually increase in the direction toward the center of the effective mask area 11; or, when the area of ​​the pattern remains unchanged, the density of the pattern may gradually increase in the direction toward the center of the effective mask area 11; or, in the direction toward the center of the effective mask area 11, the area and density of the pattern may gradually increase. Fig. 9 As shown, when the pattern density remains unchanged, the area of ​​the pattern is larger near the center of the effective mask area 11, and the area of ​​the pattern is smaller near the edge of the effective mask area 11.

[0086] This embodiment can adjust the distribution of the magnetic pattern layer 13 according to the degree of droop deformation of different areas of the mask 1. The effective mask area 11 is not supported by a frame. The closer to the center of the effective mask area 11, the greater the droop of the mask 1. Therefore, the closer to the center of the effective mask area 11, the larger the distribution area of ​​the magnetic pattern layer 13, the greater the magnetic force it is subjected to, and the closer to the edge of the effective mask area 11 (that is, the closer to the position of the mask frame glue 2), the smaller the distribution area of ​​the magnetic pattern layer 13, and the smaller the magnetic force it is subjected to. Through the differentiated design of the distribution area of ​​the magnetic pattern layer 13, the overall stress distribution of the mask 1 can be guaranteed, and the close fit between the mask 1 and the display substrate in the evaporation process can be guaranteed, thereby reducing the risk of evaporation shadow.

[0087] In some embodiments, the spacing between adjacent mask openings 14 is positively correlated with the width of the magnetic pattern layer 13 between adjacent mask openings 14 .

[0088] The multiple sub-pixel regions in the display substrate include multiple sub-pixel regions, and the sizes and / or shapes of the multiple sub-pixel regions are different. Among them, the multiple sub-pixel regions can be multiple color sub-pixel regions, such as red sub-pixel regions, blue sub-pixel regions, and green sub-pixel regions. The spacing between different adjacent sub-pixel regions can be the same or different.

[0089] Each mask opening 14 in the mask plate 1 matches the size and shape of the corresponding sub-pixel area, so that the mask plate 1 includes a plurality of mask plates, and the sizes and / or shapes of the plurality of mask openings 14 are different. The spacing between different adjacent mask openings 14 can be the same or different. The width of the magnetic pattern layer 13 between different adjacent mask openings 14 can be the same or different. The spacing between adjacent mask openings 14 is positively correlated with the width of the magnetic pattern layer 13 between adjacent mask openings 14, that is, the larger the spacing between adjacent mask openings 14, the larger the width of the magnetic pattern layer 13 between adjacent mask openings 14; the smaller the spacing between adjacent mask openings 14, the smaller the width of the magnetic pattern layer 13 between adjacent mask openings 14.

[0090] For example, the mask plate 1 includes a first mask opening and a second mask opening, the first mask opening and the second mask opening correspond to sub-pixel areas of different colors, the spacing between adjacent first mask openings is greater than the spacing between adjacent second mask openings, and the width of the magnetic pattern layer between adjacent first mask openings is greater than the width of the magnetic pattern layer between adjacent second mask openings.

[0091] In some embodiments, Figure 1 As shown, the mask assembly further includes a mask frame 2, and the mask frame 2 is arranged around the circumference of the mask 1. The mask frame 2 may include silicon.

[0092] In some embodiments, Figure 2 As shown, the mask 1 also includes a first support portion 15. The first support portion 15 is located on the side of the organic material layer 12 away from the magnetic pattern layer 13, and the first support portion 15 is located outside the effective mask area 11 and is arranged around the peripheral edge of the organic material layer 12, that is, the first support portion 15 can be arranged around multiple effective mask areas 11. The first support portion 15 can be adjacent to the mask frame 2. The setting of the first support portion 15 can make the thickness of the peripheral edge of the mask 1 consistent with the thickness of the mask frame 2, thereby improving the support effect. Among them, the first support portion 15 can include silicon.

[0093] In some embodiments, the mask 1 further includes a second support portion 16. The second support portion 16 is located on a side of the organic material layer 12 away from the magnetic pattern layer 13, and the second support portion 16 is located between the multiple effective mask areas 11. The second support portion 16 can be evenly distributed between the multiple effective mask areas 11, such as the second support portion 16 can completely cover the organic material layer 12 between the multiple effective mask areas 11.

[0094] The second support portion 16 and the first support portion 15 can be disposed in the same layer. The second support portion 16 and the first support portion 15 can be made of the same material, such as silicon. The height of the second support portion 16 is less than or equal to the height of the first support portion 15 .

[0095] According to the mask assembly provided in the embodiment of the present application, by setting the mask opening 14 in the organic material layer 12, the size of the mask opening 14 can be accurately controlled, and the accuracy and shape diversity of the mask opening 14 can be improved to meet the accuracy requirements of the evaporation process of the display substrate, and a magnetic pattern layer 13 is set between the mask openings 14, so that the mask 1 is tightly fitted to the display substrate under the action of magnetic force, so as to reduce the evaporation shadow when the to-be-evaporated area of ​​the display substrate is evaporated through the mask 1, thereby improving the evaporation effect.

[0096] Correspondingly, an embodiment of the present application also provides an evaporation device.

[0097] like Fig.12 As shown, the evaporation device provided in the embodiment of the present application includes a carrier 100, a magnetic component 200 and a mask assembly 300. Among them, the carrier 100 includes a bearing surface, and the bearing surface is used to carry a display substrate 400. The magnetic component 200 is located on the side of the carrier 100 away from the bearing surface, and the magnetic component 200 may include a plurality of magnetic plates. The mask assembly 300 is located on the side of the carrier 100 close to the bearing surface, and the organic material layer 12 in the mask assembly 300 is located between the magnetic pattern layer 13 and the carrier 100. The mask assembly 300 is the mask assembly in the above embodiment, and will not be described in detail here.

[0098] In the evaporation process, combined with Fig.13 As shown, under the action of the magnetic field, the magnetic component 200 adsorbs the mask component 300 to fix the display substrate 400 between the mask component 300 and the stage 100. The back of the display substrate 400 is arranged toward the stage 100, and the front of the display substrate 400 is arranged toward the mask component 300.

[0099] In some embodiments, the evaporation device further includes an evaporation source 500 . The evaporation source 500 is located on a side of the mask assembly 300 away from the stage 100 .

[0100] In the evaporation process, the evaporation material (such as a luminescent organic material) is disposed at the evaporation source 500, and the evaporation material is heated by the evaporation source 500, so that the atoms or molecules of the evaporation material are vaporized from its surface to form a vapor flow, which is incident on the area to be evaporated of the display substrate 400, and condensed in the area to be evaporated to form a solid film (such as a light-emitting unit).

[0101] The mask opening 14 is provided in the organic material layer 12 in the mask assembly 300, which may cause the mask 1 to wrinkle and deform. Fig.12 Under the action of the magnetic field, the mask 1 can be adsorbed and attached to the display substrate, as shown in FIG. Fig.13 shown.

[0102] According to the evaporation equipment provided in the embodiment of the present application, by setting a mask opening in the organic material layer in the mask assembly, the size of the mask opening can be accurately controlled, and the accuracy and shape diversity of the mask opening can be improved to meet the evaporation process accuracy requirements of the display substrate, and a magnetic pattern layer is set between the mask openings so that the mask is tightly fitted to the display substrate under the action of magnetic force, so as to reduce the evaporation shadow when evaporation is performed on the to-be-evaporated area of ​​the display substrate through the mask, thereby improving the evaporation effect.

[0103] Correspondingly, an embodiment of the present application also provides a method for preparing a mask assembly, which can prepare the mask assembly in the above embodiment.

[0104] like Fig.14 As shown, the method for preparing the mask assembly provided in the embodiment of the present application includes steps 110 to 130. Figure 1 As shown, the mask assembly includes a mask 1, and the mask 1 includes an effective mask area 11 for being set corresponding to the display area of ​​the display substrate. The mask 1 may include one or more effective mask areas 11. In the case where the mask 1 includes multiple effective mask areas 11, the multiple effective mask areas 11 are arranged at intervals, and are used to be set one-to-one corresponding to the display areas of multiple display substrates, so that the mask 1 is used to evaporate film layers on multiple display substrates at the same time.

[0105] Step 110: forming a magnetic pattern layer.

[0106] The magnetic pattern layer may cover a portion of the effective mask area 11 , and the magnetic pattern layer does not overlap with the area to be evaporated in the display substrate. In some embodiments, the magnetic pattern layer is also located outside the effective mask area 11 .

[0107] In some embodiments, the method for preparing the mask assembly further includes: providing a substrate, and forming a magnetic pattern layer on the substrate.

[0108] Combination Fig.15 As shown, a substrate 3 is provided. The substrate 3 may be a circular silicon wafer, etc. The size (such as radius) of the substrate 3 may be the same as the size of a wafer (the wafer may include multiple display substrates). The thickness of the substrate 3 may be 10 to 30 mm.

[0109] A magnetic material layer 4 is formed on a substrate 3 by a thin film deposition process as an electroforming cathode. Fig.16 As shown, a photoresist is coated on the magnetic material layer 4, and an exposure, development and electroforming process are performed to etch the magnetic material layer 4 into a magnetic pattern layer 13. The magnetic pattern layer 13 may include one or more combinations of magnetic aluminum, iron, cobalt, nickel and tin, etc. The thickness of the magnetic pattern layer 13 may be 0.1 to 3 um.

[0110] Step 120 : forming an organic material layer covering the magnetic pattern layer.

[0111] Combination Fig.17 As shown, an organic material layer 12 is coated on the magnetic pattern layer 13, and the organic material layer 12 completely covers the magnetic pattern layer 13. The organic material layer 12 may include a photoresist (PI) or the like. The thickness of the organic material layer 12 may be 2 to 5 um. The thickness of the organic material layer 12 needs to be uniform, such as the thickness variation of the organic material layer 12 is kept within 1%.

[0112] In some embodiments, the method for preparing the mask assembly further includes:

[0113] A transparent substrate is attached to the side of the organic material layer facing away from the magnetic pattern layer;

[0114] The substrate is etched into a first support portion and a second support portion, wherein the first support portion is located outside the effective mask area and is arranged around the peripheral edge of the organic material layer, and the second support portion is located between the multiple effective mask areas; the height of the second support portion is less than or equal to the height of the first support portion;

[0115] The transparent substrate is removed.

[0116] Combination Fig.18 As shown, a transparent substrate 5 is attached to the organic material layer 12, and the transparent substrate 5 is light-transmissive, so that the mask and the mask frame can be welded later. The transparent substrate 5 can include transparent borosilicate or quartz glass.

[0117] Combination Fig.19 As shown, the current structure (including the transparent substrate 5, the organic material layer 12, the magnetic pattern layer 13 and the substrate 3) is turned over so that the substrate 3 faces upward. The substrate 3 is etched to obtain the first support portion 15 and the second support portion 16. The first support portion 15 is arranged outside the effective mask area 11 around the peripheral edge of the organic material layer 12. The first support portion 15 can make the mask retain the peripheral thickness of the mask frame. The second support portion 16 is located between multiple effective mask areas 11. The height of the second support portion 16 is less than or equal to the height of the first support portion 15.

[0118] In some embodiments, the method for preparing the mask assembly further includes:

[0119] The mask is combined with a mask frame, and the mask frame is arranged around the circumference of the mask.

[0120] The mask plate and the mask plate frame can be combined by welding or bonding. Fig. 20As shown, a mask (including an organic material layer 12, a magnetic pattern layer 13, a first support portion 15 and a second support portion 16) is welded to a mask frame 2 by laser, so that the mask frame 2 is arranged around the periphery of the mask.

[0121] Then, the organic material layer 12 is irradiated with UV light to peel off the transparent substrate 5 attached to the surface.

[0122] Step 130 , forming a plurality of mask openings spaced apart in the effective mask area of ​​the organic material layer, the mask openings being used to correspond to the to-be-evaporated areas in the display area, and the magnetic pattern layer being located between the plurality of mask openings in the effective mask area.

[0123] Then, combine Fig.21 As shown, the alignment holes on the mask frame 2 are used to establish a coordinate system, and laser processing is used to form a mask opening 14 in the organic material layer 12. It should be noted that the alignment holes used to form the mask opening 14 are consistent with the alignment holes in the evaporation process.

[0124] The mask opening 14 is used to be arranged corresponding to the area to be evaporated in the display area (such as a sub-pixel area). A plurality of mask openings 14 may be formed in the organic material layer 12, and the plurality of mask openings 14 may be arranged one-to-one corresponding to the plurality of areas to be evaporated in the display area (such as a plurality of sub-pixel areas). In the case where the area to be evaporated is a sub-pixel area, the film layer evaporated in the area to be evaporated of the display substrate using the mask plate 1 may include a light-emitting unit.

[0125] The magnetic pattern layer 13 is located between the plurality of mask openings 14 in the effective mask area 11. By adjusting the shape, area and position of the magnetic pattern layer 13 between the plurality of mask openings 14, the magnitude and distribution of the magnetic force on the mask can be adjusted.

[0126] In the related art, the metal mask used in glass-based OLEDs obtains the mask opening by wet etching, but the size of the mask opening is large and the manufacturing precision is poor, which cannot meet the ultra-high PPI (>3000PPI) requirements of silicon-based OLEDs. Moreover, after the mask opening is formed, the metal mask needs to be stretched and welded to the metal frame. The process is cumbersome, and the stretching precision of the metal mask is difficult to control. Excessive or insufficient tension may cause serious deformation of the metal mask, resulting in poor shadow and color mixing. In addition, when the metal mask is welded to the metal frame glue, it is easy to have cold welding or welding penetration, resulting in a loose connection, which is difficult to manufacture and has high operating costs.

[0127] Based on this, the mask plate 1 in this embodiment is first combined with the mask plate frame 2 (such as welding), and then a mask opening 14 is formed in the organic material layer 12 of the mask plate 1 by laser drilling, which omits the cumbersome net stretching process, reduces the risk of damage to the mask plate 1, improves the position accuracy of the mask opening 14, greatly reduces the difficulty of production and operating costs, saves time, and improves production efficiency. Moreover, by combining the organic material layer 12 with the magnetic pattern layer 13, the organic material layer 12 is used as the opening definition layer, and laser processing can accurately control the opening size in the organic material layer 12 and meet the diversity of the opening shape. The magnetic pattern layer 13 can make the mask plate 1 fit closely with the display substrate under the action of magnetic force, reduce the evaporation shadow, and improve the evaporation effect.

[0128] The terms "first", "second", etc. in the specification and claims of this application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first", "second", etc. are generally of the same type, and the number of objects is not limited. For example, the first object can be one or more.

[0129] In the description of the present application, “plurality” means two or more.

[0130] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0131] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

1. A mask assembly, characterized in that: The invention comprises a mask plate, wherein the mask plate comprises an effective mask area for being arranged corresponding to a display area of ​​a display substrate; the mask plate comprises: The organic material layer comprises a plurality of mask openings located in the effective mask area and arranged at intervals, wherein the mask openings are used to be arranged corresponding to the areas to be evaporated in the display area; The magnetic pattern layer is located on one side of the organic material layer and between the plurality of mask openings in the effective mask area.

2. The mask assembly according to claim 1, characterized in that: The magnetic pattern layer is also located outside the effective mask area.

3. The mask assembly according to claim 1, characterized in that: The magnetic pattern layer is arranged around the mask opening.

4. The mask assembly according to claim 1, characterized in that: The plurality of mask openings are distributed in multiple rows and columns, and the magnetic pattern layer is located between the mask openings in two adjacent rows and / or two adjacent columns.

5. The mask assembly according to claim 1, characterized in that: The magnetic pattern layer includes a plurality of patterns located between a plurality of the mask openings; A plurality of the patterns are evenly distributed; or, In a direction toward the center of the effective mask area, the area and / or density of the pattern gradually increases.

6. The mask assembly according to claim 1, characterized in that: The spacing between adjacent mask openings is positively correlated with the width of the magnetic pattern layer between adjacent mask openings.

7. The mask assembly according to claim 1, characterized in that: The mask also includes: The first supporting portion is located at a side of the organic material layer away from the magnetic pattern layer and is located outside the effective mask area and is arranged around a peripheral edge of the organic material layer.

8. The mask assembly according to claim 7, characterized in that: The mask plate includes a plurality of effective mask areas arranged at intervals; the mask plate also includes: The second supporting portion is located at a side of the organic material layer away from the magnetic pattern layer and between the plurality of effective mask areas; the height of the second supporting portion is less than or equal to the height of the first supporting portion.

9. The mask assembly according to claim 1, characterized in that: The mask assembly also includes: The mask frame is arranged around the circumference of the mask.

10. The mask assembly according to any one of claims 1 to 9, characterized in that: The longitudinal section of the mask opening is trapezoidal.

11. A vapor deposition device, characterized in that: include: A carrier, including a carrying surface, for carrying a display substrate; A magnetic component, located on a side of the carrier away from the carrying surface; The mask assembly according to any one of claims 1 to 10 is located on a side of the carrier close to the carrying surface.

12. A method for preparing a mask assembly, characterized in that: The mask assembly includes a mask, and the mask includes an effective mask area for being arranged corresponding to a display area of ​​a display substrate; the method includes: forming a magnetic pattern layer; forming an organic material layer covering the magnetic pattern layer; A plurality of mask openings are formed in the effective mask area of ​​the organic material layer. The mask openings are used to correspond to the areas to be evaporated in the display area. The magnetic pattern layer is located between the plurality of mask openings in the effective mask area.

13. The method for preparing a mask assembly according to claim 12, characterized in that: Before forming a plurality of mask openings spaced apart from each other in the effective mask region of the organic material layer, the method further comprises: The mask is combined with a mask frame, and the mask frame is arranged around the circumference of the mask.

14. The method for preparing a mask assembly according to claim 12, characterized in that: The mask plate includes a plurality of effective mask areas arranged at intervals; the method further includes: Providing a substrate, on which the magnetic pattern layer is formed; Before forming a plurality of mask openings spaced apart from each other in the effective mask region of the organic material layer, the method further comprises: Attaching a transparent substrate to a side of the organic material layer away from the magnetic pattern layer; The substrate is etched into a first supporting portion and a second supporting portion, wherein the first supporting portion is located outside the effective mask area and is arranged around the peripheral edge of the organic material layer, and the second supporting portion is located between a plurality of the effective mask areas; the height of the second supporting portion is less than or equal to the height of the first supporting portion; The transparent substrate is removed.

Images